WO2022172479A1 - Rotating electrical machine - Google Patents

Rotating electrical machine Download PDF

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Publication number
WO2022172479A1
WO2022172479A1 PCT/JP2021/021979 JP2021021979W WO2022172479A1 WO 2022172479 A1 WO2022172479 A1 WO 2022172479A1 JP 2021021979 W JP2021021979 W JP 2021021979W WO 2022172479 A1 WO2022172479 A1 WO 2022172479A1
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WO
WIPO (PCT)
Prior art keywords
circumferential
magnet
pair
magnets
viewed
Prior art date
Application number
PCT/JP2021/021979
Other languages
French (fr)
Japanese (ja)
Inventor
正倫 綿引
Original Assignee
日本電産株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日本電産株式会社 filed Critical 日本電産株式会社
Priority to CN202180093476.2A priority Critical patent/CN116888861A/en
Publication of WO2022172479A1 publication Critical patent/WO2022172479A1/en

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K1/00—Details of the magnetic circuit
    • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
    • H02K1/22—Rotating parts of the magnetic circuit
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K1/00—Details of the magnetic circuit
    • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
    • H02K1/22—Rotating parts of the magnetic circuit
    • H02K1/27—Rotor cores with permanent magnets
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K21/00—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets
    • H02K21/12—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets
    • H02K21/14—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets with magnets rotating within the armatures

Definitions

  • the present invention relates to rotating electric machines.
  • a rotary electric machine such as an interior permanent magnet synchronous motor (IPMSM) is known that includes a rotor core and permanent magnets arranged in holes provided in the rotor core.
  • IPMSM interior permanent magnet synchronous motor
  • Patent Document 1 discloses a first magnet in which permanent magnets are arranged in a V shape, and magnetization directions inside the magnets of each of two sets of magnet portions forming the V shape are directed to intersect each other.
  • a rotary electric machine is disclosed in which demagnetization of a magnet is suppressed by arranging a portion and a second magnet portion.
  • Patent Document 2 discloses a radially inner portion on the outer peripheral surface of the rotor core. It is disclosed to provide a recessed groove in the .
  • the provision of grooves on the outer peripheral surface of the rotor core increases the air gap between the rotor core and the stator, thereby reducing the electromagnetic excitation force in the circumferential direction.
  • the drive range is wide, and as the number of revolutions of the motor increases, more d-axis current may flow in order to reduce the induced voltage.
  • the balance relationship between the d-axis magnetic flux and the q-axis magnetic flux in the motor also changes significantly, and the electromagnetic excitation force that excites the motor also changes significantly.
  • a circumferential electromagnetic excitation force becomes a noise source at low speed
  • a radial electromagnetic excitation force becomes a noise source at high speed. Therefore, it is necessary to deal with different components of the electromagnetic excitation force in the circumferential direction and the radial direction with one motor shape. cannot be said to have been taken into consideration.
  • the present invention has been made in consideration of the above points, and an object of the present invention is to provide a rotating electric machine that can reduce noise regardless of the number of revolutions of the motor.
  • One aspect of the rotating electrical machine of the present invention includes a rotor rotatable about a central axis, and a stator positioned radially outward of the rotor, the rotor including a rotor core having a plurality of housing holes; and a plurality of magnets respectively housed within the plurality of housing holes, wherein the stator includes an annular core-back surrounding the rotor core, and a stator extending radially inward from the core-back and spaced circumferentially from the core-back. a stator core having a plurality of teeth arranged side by side; and a plurality of coils attached to the stator core.
  • the rotor core has a pair of grooves recessed radially inward at intervals on both sides in the circumferential direction of the outer peripheral surface of the rotor core across the q-axis when viewed in the axial direction.
  • L1 is the maximum dimension of the grooves
  • L2 is the minimum dimension of the interval between the pair of grooves in the circumferential direction.
  • noise can be reduced in a rotating electric machine regardless of the number of revolutions of the motor.
  • FIG. 1 is a cross-sectional view showing a rotating electrical machine of this embodiment.
  • FIG. 2 is a cross-sectional view showing a part of the rotating electric machine of this embodiment, taken along the line II--II in FIG.
  • FIG. 3 is a sectional view showing the magnetic pole portions of the rotor and part of the stator core of the present embodiment.
  • FIG. 4 is an enlarged cross-sectional view of the periphery of the groove facing the teeth 66F in the radial direction.
  • FIG. 5 is a diagram showing the relationship between the number of revolutions of the motor and the increase/decrease ratio of the 12th order radial electromagnetic excitation force.
  • FIG. 1 is a cross-sectional view showing a rotating electrical machine of this embodiment.
  • FIG. 2 is a cross-sectional view showing a part of the rotating electric machine of this embodiment, taken along the line II--II in FIG.
  • FIG. 3 is a sectional view showing the magnetic pole portions of the rotor and part of
  • FIG. 6 is a diagram showing the relationship between the number of rotations of the motor and the increase/decrease ratio of the twelfth circumferential electromagnetic excitation force.
  • FIG. 7 is a diagram showing the relationship between the number of grooves and the increase/decrease ratio of the average torque, and the relationship between the number of grooves and the increase/decrease ratio of the electromagnetic excitation force of 12th electrical angle.
  • FIG. 8 is an enlarged cross-sectional view of the periphery of a groove portion of a rotating electric machine having "one groove".
  • FIG. 9 shows the groove width L3, the average torque, the radial electromagnetic excitation force of the twelfth electrical angle, and the circumferential electromagnetic force of the twelfth electrical angle in the rotating electrical machine having the groove 80C, as compared with the rotating electrical machine having no groove. It is a figure which shows the relationship with each increase-and-decrease ratio of vibration force.
  • FIG. 10 is a diagram showing the relationship between the groove width L3 and the increase/decrease ratio of the average torque, the radial electromagnetic excitation force of the 12th electrical angle, and the circumferential electromagnetic excitation force of the 12th electrical angle.
  • 11 shows the relationship between the minimum dimension L2 of the circumferential interval between the grooves and the ratio of increase/decrease of the average torque, radial electromagnetic excitation force of 12th electrical angle, and circumferential electromagnetic excitation force of 12th electrical angle. It is a diagram.
  • the Z-axis direction shown as appropriate in each figure is a vertical direction in which the positive side is the "upper side” and the negative side is the “lower side.”
  • a central axis J appropriately shown in each figure is a virtual line parallel to the Z-axis direction and extending in the vertical direction.
  • the axial direction of the central axis J that is, the direction parallel to the vertical direction is simply referred to as the "axial direction”
  • the radial direction around the central axis J is simply referred to as the "radial direction”
  • the central axis J is simply referred to as the "circumferential direction”.
  • An arrow ⁇ appropriately shown in each figure indicates the circumferential direction.
  • the arrow ⁇ points clockwise around the central axis J when viewed from above.
  • the side toward which the arrow ⁇ is directed that is, the side proceeding clockwise when viewed from the upper side
  • the side opposite to the direction of the arrow ⁇ , that is, the side proceeding counterclockwise when viewed from above is called the “other side in the circumferential direction”.
  • the rotating electrical machine 1 of this embodiment is an inner rotor type rotating electrical machine.
  • the rotating electrical machine 1 is a three-phase AC rotating electrical machine.
  • the rotary electric machine 1 is, for example, a three-phase motor that is driven by being supplied with three-phase AC power.
  • the rotating electric machine 1 includes a housing 2, a rotor 10, a stator 60, a bearing holder 4, and bearings 5a and 5b.
  • the housing 2 accommodates the rotor 10, the stator 60, the bearing holder 4, and the bearings 5a and 5b inside.
  • the bottom of housing 2 holds a bearing 5b.
  • a bearing holder 4 holds a bearing 5a.
  • the bearings 5a, 5b are, for example, ball bearings.
  • the stator 60 is located radially outside the rotor 10 .
  • the stator 60 has a stator core 61 , insulators 64 and multiple coils 65 .
  • Stator core 61 has a core back 62 and a plurality of teeth 63 .
  • the core back 62 is located radially outside the rotor core 20, which will be described later. As shown in FIG. 2 , core back 62 has an annular shape surrounding rotor core 20 .
  • the core back 62 has an annular shape centering on the central axis J, for example.
  • a plurality of teeth 63 extend radially inward from the core back 62 .
  • the plurality of teeth 63 are arranged side by side at intervals in the circumferential direction.
  • the multiple teeth 63 are, for example, arranged at regular intervals along the circumferential direction.
  • 48 teeth 63 are provided. That is, the number of slots 67 of the rotating electric machine 1 is 48, for example.
  • each of the teeth 63 has a base portion 63a and an umbrella portion 63b.
  • the base portion 63 a extends radially inward from the core back 62 .
  • the circumferential dimension of the base portion 63a is, for example, the same throughout the radial direction. Note that the circumferential dimension of the base portion 63a may decrease, for example, toward the radially inner side.
  • the umbrella portion 63b is provided at the radially inner end portion of the base portion 63a.
  • the umbrella portion 63b protrudes to both sides in the circumferential direction from the base portion 63a.
  • the circumferential dimension of the umbrella portion 63b is greater than the circumferential dimension of the radially inner end portion of the base portion 63a.
  • a radially inner surface of the umbrella portion 63b is a curved surface along the circumferential direction.
  • a radially inner surface of the umbrella portion 63b extends in an arc around the central axis J when viewed in the axial direction.
  • the radially inner surface of the umbrella portion 63b faces the outer peripheral surface of the rotor core 20 to be described later with a gap in the radial direction.
  • Umbrella portions 63b of teeth 63 adjacent to each other in the circumferential direction are arranged side by side with a gap in the circumferential direction.
  • a plurality of coils 65 are attached to the stator core 61 . As shown in FIG. 1, the plurality of coils 65 are attached to the teeth 63 via insulators 64, for example.
  • the coil 65 is distributed winding. That is, each coil 65 is wound over a plurality of teeth 63 .
  • the coil 65 is wound in full pitch. That is, the circumferential pitch between the slots of the stator 60 into which the coils 65 are inserted is equal to the circumferential pitch of the magnetic poles generated when the stator 60 is supplied with the three-phase AC power.
  • the number of poles of the rotary electric machine 1 is eight, for example. That is, the rotary electric machine 1 is, for example, an 8-pole 48-slot rotary electric machine.
  • the number of poles is N
  • the number of slots is N ⁇ 6. 2 and 3, illustration of the insulator 64 is omitted.
  • the rotor 10 is rotatable around the central axis J.
  • the rotor 10 has a shaft 11 , a rotor core 20 and a plurality of magnets 40 .
  • the shaft 11 has a columnar shape extending in the axial direction around the central axis J.
  • the shaft 11 is rotatably supported around a central axis J by bearings 5a and 5b.
  • the rotor core 20 is a magnetic material. Rotor core 20 is fixed to the outer peripheral surface of shaft 11 . Rotor core 20 has a through hole 21 that axially penetrates rotor core 20 . As shown in FIG. 2, the through hole 21 has a circular shape centered on the central axis J when viewed in the axial direction.
  • the shaft 11 is passed through the through hole 21 .
  • the shaft 11 is fixed in the through hole 21 by, for example, press fitting.
  • the rotor core 20 is configured, for example, by laminating a plurality of electromagnetic steel sheets in the axial direction.
  • the rotor core 20 has a plurality of accommodation holes 30.
  • the plurality of housing holes 30 for example, penetrate the rotor core 20 in the axial direction.
  • a plurality of magnets 40 are housed inside the plurality of housing holes 30, respectively.
  • a method for fixing the magnet 40 in the accommodation hole 30 is not particularly limited.
  • the multiple accommodation holes 30 include a pair of first accommodation holes 31 a and 31 b and a second accommodation hole 32 .
  • the types of the plurality of magnets 40 are not particularly limited.
  • the magnet 40 may be, for example, a neodymium magnet or a ferrite magnet.
  • the multiple magnets 40 include a pair of first magnets 41 a and 41 b and a second magnet 42 .
  • the pair of first magnets 41a and 41b and the second magnet 42 form poles.
  • the pair of first accommodation holes 31a, 31b, the pair of first magnets 41a, 41b, the second accommodation holes 32, and the second magnets 42 are provided at intervals in the circumferential direction.
  • the pair of first accommodation holes 31a, 31b, the pair of first magnets 41a, 41b, the second accommodation holes 32, and the second magnets 42 are provided, for example, eight each.
  • the rotor 10 has a plurality of magnetic pole portions 70 each including a pair of first housing holes 31a, 31b, a pair of first magnets 41a, 41b, a second housing hole 32, and a second magnet 42.
  • eight magnetic pole portions 70 are provided.
  • the plurality of magnetic pole portions 70 are, for example, arranged at regular intervals along the circumferential direction.
  • the plurality of magnetic pole portions 70 include a plurality of magnetic pole portions 70N having N-pole magnetic poles on the outer peripheral surface of the rotor core 20 and a plurality of magnetic pole portions 70S having S-pole magnetic poles on the outer peripheral surface of the rotor core 20, respectively.
  • four magnetic pole portions 70N and four magnetic pole portions 70S are provided.
  • the four magnetic pole portions 70N and the four magnetic pole portions 70S are alternately arranged along the circumferential direction.
  • the configuration of each magnetic pole portion 70 is the same except that the magnetic poles on the outer peripheral surface of the rotor core 20 are different and the positions in the circumferential direction are different.
  • the pair of first accommodation holes 31a and 31b are arranged with a space therebetween in the circumferential direction.
  • the first accommodation hole 31a is positioned, for example, on one circumferential side (+ ⁇ side) of the first accommodation hole 31b.
  • the first accommodation holes 31a and 31b extend substantially linearly in a direction oblique to the radial direction, for example, when viewed in the axial direction.
  • the pair of first receiving holes 31a and 31b extend in directions away from each other in the circumferential direction as viewed in the axial direction from the radially inner side toward the radially outer side. That is, the circumferential distance between the first receiving holes 31a and 31b increases from the radially inner side to the radially outer side.
  • the first accommodation hole 31a is located on one side in the circumferential direction, for example, from the radially inner side to the radially outer side.
  • the first accommodation hole 31b is located, for example, on the other circumferential side ( ⁇ side) from the radially inner side toward the radially outer side.
  • the radially outer ends of the first accommodation holes 31 a and 31 b are positioned at the radially outer peripheral edge of the rotor core 20 .
  • the first accommodation holes 31a and 31b are arranged, for example, in the axial direction so as to sandwich the magnetic pole center line IL1 shown in FIG. 3, which constitutes the d-axis, in the circumferential direction.
  • the magnetic pole center line IL1 is a virtual line passing through the circumferential center of the magnetic pole portion 70 and the central axis J and extending in the radial direction.
  • the first receiving holes 31a and the first receiving holes 31b are, for example, arranged line-symmetrically with respect to the magnetic pole center line IL1 when viewed in the axial direction.
  • description of the first receiving hole 31b may be omitted for the same configuration as the first receiving hole 31a except that it is line-symmetrical with respect to the magnetic pole center line IL1.
  • the first accommodation hole 31a has a first linear portion 31c, an inner end portion 31d, and an outer end portion 31e.
  • the first linear portion 31c linearly extends in the direction in which the first receiving hole 31a extends when viewed in the axial direction.
  • the first linear portion 31c has, for example, a rectangular shape when viewed in the axial direction.
  • the inner end portion 31d is connected to the radially inner end portion of the first straight portion 31c.
  • the inner end portion 31d is a radially inner end portion of the first receiving hole 31a.
  • the outer end portion 31e is connected to the radially outer end portion of the first straight portion 31c.
  • the outer end portion 31e is a radially outer end portion of the first accommodation hole 31a.
  • the first accommodation hole 31b has a first linear portion 31f, an inner end portion 31g, and an outer end portion 31h.
  • the second accommodation hole 32 is located between the radial outer ends of the pair of first accommodation holes 31a and 31b in the circumferential direction. That is, in the present embodiment, the second accommodation hole 32 is located between the outer end portion 31e and the outer end portion 31h in the circumferential direction.
  • the second receiving hole 32 extends substantially linearly in a direction orthogonal to the radial direction, for example, when viewed in the axial direction.
  • the second receiving hole 32 extends, for example, in a direction orthogonal to the magnetic pole center line IL1 when viewed in the axial direction.
  • the pair of first receiving holes 31a and 31b and the second receiving hole 32 are arranged, for example, along a ⁇ shape when viewed in the axial direction.
  • a certain object extends in a direction orthogonal to a certain direction
  • a certain object extends in a direction strictly orthogonal to a certain direction
  • a certain object It also includes the case where it extends in a direction substantially orthogonal to a certain direction.
  • a direction substantially orthogonal to a certain direction includes, for example, a direction inclined within a range of several degrees [°] with respect to a direction strictly orthogonal to a certain direction due to manufacturing tolerances or the like.
  • the magnetic pole center line IL1 passes through the center of the second housing hole 32 in the circumferential direction. That is, the circumferential position of the circumferential center of the second housing hole 32 coincides with, for example, the circumferential position of the magnetic pole portion 70 .
  • the shape of the second housing hole 32 when viewed in the axial direction is, for example, a line-symmetrical shape about the magnetic pole center line IL1.
  • the second accommodation hole 32 is positioned at the radially outer peripheral edge of the rotor core 20 .
  • the second accommodation hole 32 has a second linear portion 32a, one end portion 32b, and the other end portion 32c.
  • the second linear portion 32a linearly extends in the direction in which the second receiving hole 32 extends when viewed in the axial direction.
  • the second linear portion 32a has, for example, a rectangular shape when viewed in the axial direction.
  • the one end portion 32b is connected to the end portion on one circumferential side (+ ⁇ side) of the second linear portion 32a.
  • the one end portion 32b is an end portion on one side in the circumferential direction of the second accommodation hole 32 .
  • the one end portion 32b is spaced apart from the outer end portion 31e of the first accommodating hole 31a in the circumferential direction ( ⁇ side).
  • the other end 32c is connected to the end of the second linear portion 32a on the other circumferential side ( ⁇ side).
  • the other end 32c is the end of the second receiving hole 32 on the other side in the circumferential direction.
  • the other end portion 32c is arranged on one circumferential side of the outer end portion 31h of the first accommodation hole 31b with a space therebetween.
  • the pair of first magnets 41a and 41b are housed inside the pair of first housing holes 31a and 31b, respectively.
  • the first magnet 41a is housed inside the first housing hole 31a.
  • the first magnet 41b is housed inside the first housing hole 31b.
  • the pair of first magnets 41a and 41b has, for example, a rectangular shape when viewed in the axial direction.
  • the lengths in the direction in which the pair of first magnets 41a and 41b extend are the same.
  • the lengths of the first magnets 41a and 41b in the direction orthogonal to the direction in which the pair of first magnets 41a and 41b extend are the same.
  • the first magnets 41a and 41b are rectangular parallelepipeds, for example. Although not shown, the first magnets 41a and 41b are provided, for example, over the entirety of the first receiving holes 31a and 31b in the axial direction. The pair of first magnets 41a and 41b are arranged with a space therebetween in the circumferential direction. The first magnet 41a is positioned, for example, on one circumferential side (+ ⁇ side) of the first magnet 41b.
  • the first magnet 41a extends along the first receiving hole 31a when viewed in the axial direction.
  • the first magnet 41b extends along the first receiving hole 31b when viewed in the axial direction.
  • the first magnets 41a and 41b for example, extend substantially linearly in a direction oblique to the radial direction when viewed in the axial direction.
  • the pair of first magnets 41a and 41b extend in directions away from each other in the circumferential direction as viewed in the axial direction from the radially inner side toward the radially outer side. That is, the circumferential distance between the first magnets 41a and 41b increases from the radially inner side to the radially outer side.
  • the first magnet 41a is positioned, for example, on one circumferential side (+ ⁇ side) from the radially inner side to the radially outer side.
  • the first magnet 41b is positioned, for example, on the other circumferential side ( ⁇ side) from the radially inner side to the radially outer side.
  • the first magnet 41a and the first magnet 41b are arranged, for example, so as to sandwich the magnetic pole center line IL1 in the circumferential direction when viewed in the axial direction.
  • the first magnet 41a and the first magnet 41b are arranged line-symmetrically with respect to the magnetic pole center line IL1, for example, when viewed in the axial direction.
  • the description of the first magnet 41b may be omitted for the same configuration as the first magnet 41a except that it is line-symmetrical with respect to the magnetic pole center line IL1.
  • the first magnet 41a is fitted in the first accommodation hole 31a. More specifically, the first magnet 41a is fitted inside the first linear portion 31c. Of the side surfaces of the first magnet 41a, both side surfaces in the direction perpendicular to the direction in which the first straight portion 31c extends are in contact with the inner side surface of the first straight portion 31c, for example. In the direction in which the first linear portion 31c extends when viewed in the axial direction, the length of the first magnet 41a is, for example, the same as the length of the first linear portion 31c.
  • both ends of the first magnet 41a in the extending direction are arranged apart from both ends of the first accommodating hole 31a in the extending direction.
  • an inner end portion 31d and an outer end portion 31e are arranged adjacent to each other on both sides of the first magnet 41a in the direction in which the first magnet 41a extends.
  • the inner end portion 31d constitutes the first flux barrier portion 51a.
  • the outer end portion 31e constitutes a first flux barrier portion 51b. That is, the rotor core 20 has a pair of first flux barrier portions 51a and 51b arranged to sandwich the first magnet 41a in the direction in which the first magnet 41a extends when viewed in the axial direction.
  • the rotor core 20 has a pair of first flux barrier portions 51c and 51d arranged to sandwich the first magnet 41b in the direction in which the first magnet 41b extends when viewed in the axial direction.
  • the rotor core 20 has a pair of first flux barrier portions 51a and 51b arranged with each of the first magnets 41a and 41b interposed therebetween in the direction in which the first magnets 41a and 41b extend when viewed in the axial direction. , 51c and 51d.
  • the first flux barrier portions 51a, 51b, 51c, and 51d, the second flux barrier portions 52a and 52b, which will be described later, and the groove portion 80, which will be described later, are portions that can suppress the flow of magnetic flux. That is, it is difficult for magnetic flux to pass through each flux barrier portion and groove portion.
  • Each flux barrier portion and groove portion is not particularly limited as long as it can suppress the flow of magnetic flux, and may include a void portion or a non-magnetic portion such as a resin portion.
  • the second magnet 42 is housed inside the second housing hole 32 .
  • the second magnet 42 is arranged at a circumferential position between the pair of first magnets 41a and 41b radially outside the radial inner end portions of the pair of first magnets 41a and 41b.
  • the second magnet 42 extends along the second receiving hole 32 when viewed in the axial direction.
  • the second magnet 42 extends in a direction perpendicular to the radial direction when viewed in the axial direction.
  • the pair of first magnets 41a and 41b and the second magnet 42 are arranged, for example, along a ⁇ shape when viewed in the axial direction.
  • the second magnet is arranged at a circumferential position between the pair of first magnets
  • the circumferential position of the second magnet is between the pair of first magnets.
  • the radial position of the second magnet with respect to the first magnet is not particularly limited as long as it is included in the directional position.
  • the shape of the second magnet 42 when viewed in the axial direction is, for example, a line-symmetrical shape with respect to the magnetic pole center line IL1.
  • the second magnet 42 has, for example, a rectangular shape when viewed in the axial direction.
  • the second magnet 42 has, for example, a rectangular parallelepiped shape.
  • the second magnet 42 is provided, for example, over the entirety of the second housing hole 32 in the axial direction.
  • the radially inner portion of the second magnet 42 is positioned, for example, between the radially outer ends of the pair of first magnets 41a and 41b in the circumferential direction.
  • the radially outer portion of the second magnet 42 is positioned, for example, radially outer than the pair of first magnets 41a and 41b.
  • the second magnet 42 is fitted inside the second housing hole 32 . More specifically, the second magnet 42 is fitted inside the second straight portion 32a. Of the side surfaces of the second magnet 42, both side surfaces in the radial direction perpendicular to the direction in which the second straight portion 32a extends are in contact with, for example, the inner side surface of the second straight portion 32a.
  • the length of the second magnet 42 is, for example, the same as the length of the second straight portion 32a in the direction in which the second straight portion 32a extends when viewed in the axial direction.
  • both ends of the second magnet 42 in the extending direction are arranged apart from both ends of the second receiving hole 32 in the extending direction.
  • one end portion 32b and the other end portion 32c are arranged adjacent to each other on both sides of the second magnet 42 in the direction in which the second magnet 42 extends.
  • the one end portion 32b constitutes the second flux barrier portion 52a.
  • the other end portion 32c constitutes a second flux barrier portion 52b.
  • the rotor core 20 has a pair of second flux barrier portions 52a and 52b arranged to sandwich the second magnet 42 in the direction in which the second magnet 42 extends when viewed in the axial direction.
  • the pair of second flux barrier portions 52a and 52b and the second magnet 42 are composed of the first flux barrier portion 51b positioned radially outward of the pair of first flux barrier portions 51a and 51b sandwiching the first magnet 41a, Among the pair of first flux barrier portions 51c and 51d sandwiching one magnet 41b, it is located between the first flux barrier portion 51d located radially outside and the first flux barrier portion 51d in the circumferential direction.
  • the magnetic poles of the first magnet 41a are arranged along the direction orthogonal to the direction in which the first magnet 41a extends when viewed in the axial direction.
  • the magnetic poles of the first magnet 41b are arranged along the direction orthogonal to the direction in which the first magnet 41b extends when viewed in the axial direction.
  • the magnetic poles of the second magnet 42 are arranged along the radial direction.
  • the magnetic pole located radially outward among the magnetic poles of the first magnet 41a, the magnetic pole located radially outward among the magnetic poles of the first magnet 41b, and the magnetic pole located radially outward among the magnetic poles of the second magnet 42, are the same as each other.
  • the magnetic pole located radially inward among the magnetic poles of the first magnet 41a, the magnetic pole located radially inward among the magnetic poles of the first magnet 41b, and the magnetic pole located radially inward among the magnetic poles of the second magnet 42, are the same as each other.
  • the radially outer magnetic pole of the first magnet 41a and the radially outer magnetic pole of the first magnet 41b and the magnetic pole of the second magnet 42 The magnetic pole positioned radially outward is, for example, the N pole.
  • the radially inner magnetic pole of the first magnet 41a, the radially inner magnetic pole of the first magnet 41b, and the radially inner magnetic pole of the second magnet 42 The magnetic pole to be used is, for example, the S pole.
  • the magnetic pole of each magnet 40 is reversed with respect to the magnetic pole portion 70N. That is, in the magnetic pole portion 70S, the radially outer magnetic pole of the first magnet 41a, the radially outer magnetic pole of the first magnet 41b, and the radially outer magnetic pole of the second magnet 42
  • the magnetic pole located at is, for example, the S pole.
  • the magnetic pole to be used is, for example, the N pole.
  • the circumferential center of the second magnet 42 is arranged at the same circumferential position as the circumferential center of one tooth 63 (hereinafter simply referred to as a "certain state")
  • the circumferential center is Teeth 63 arranged at the same circumferential position as the circumferential center of the second magnet 42 are referred to as teeth 66A.
  • 2 and 3 show an example of such a certain state. That is, in a certain state shown in FIGS. 2 and 3, the tooth 66A corresponds to "one certain tooth”.
  • the magnetic pole center line IL1 passes through the circumferential center of the teeth 66A when viewed in the axial direction.
  • “a certain state” is a state in which "the center position of the teeth 66A in the circumferential direction coincides with the magnetic pole center line IL1, which is the d-axis”.
  • teeth 63 adjacent to the teeth 66A on one side in the circumferential direction (+ ⁇ side) are called teeth 66B.
  • a tooth 63 adjacent to the tooth 66A on the other circumferential side ( ⁇ side) is called a tooth 66C.
  • a tooth 63 adjacent to one side of the tooth 66B in the circumferential direction is called a tooth 66D.
  • the teeth 63 adjacent to the teeth 66C on the other side in the circumferential direction are called teeth 66E.
  • a tooth 63 adjacent to one side in the circumferential direction of the tooth 66D is called a tooth 66F.
  • the teeth 63 adjacent to the teeth 66E on the other side in the circumferential direction are called teeth 66G.
  • the rotor core 20 has grooves 80 .
  • the groove portion 80 has a pair of groove portions 80A and 80B.
  • the groove portion 80A and the groove portion 80B are recessed radially inward from the outer peripheral surface 20a when viewed in the axial direction.
  • Groove portion 80A and groove portion 80B each penetrate rotor core 20 in the axial direction.
  • the groove portion 80A and the groove portion 80B are provided for each q-axis IL2.
  • the q-axis IL2 is an axis extending in a direction electrically perpendicular to the d-axis.
  • FIG. 4 is an enlarged sectional view of the periphery of the groove portion 80 radially facing the teeth 66F.
  • the groove portion 80A and the groove portion 80B are spaced apart from each other in the circumferential direction with the q-axis IL2 interposed therebetween.
  • the groove portion 80 has a groove portion 80A and a groove portion 80B extending in the circumferential direction with a gap located on the q-axis IL2 when viewed in the axial direction.
  • Groove portion 80A is positioned on one circumferential side of q-axis IL2.
  • Groove portion 80B is located on the other circumferential side of q-axis IL2.
  • the groove portion 80A and the groove portion 80B are arranged line-symmetrically with respect to the q-axis IL2 when viewed in the axial direction.
  • the description of the groove portion 80B may be omitted for the configuration similar to that of the groove portion 80A except that the groove portion 80B is line-symmetrical with respect to the q-axis IL2.
  • the groove portion 80 located on the q-axis IL2 when viewed in the axial direction By providing the groove portion 80 located on the q-axis IL2 when viewed in the axial direction, the radial electromagnetic excitation force during high-speed rotation can be reduced, and the radial vibration of the twelfth electrical angle generated by the radial electromagnetic excitation force can be suppressed. can. If the groove portion 80A and the groove portion 80B are continuously provided in the circumferential direction including the position of the q-axis IL2 without leaving an interval therebetween, the circumferential electromagnetic excitation force increases during low-speed rotation. According to the present embodiment, the groove 80A and the groove 80B are provided on both sides in the circumferential direction with the q-axis IL2 interposed therebetween.
  • High-speed rotation means, for example, that the rotation speed of the motor (rotor core 20) is 5000 (rpm) or more.
  • Low-speed rotation means, for example, that the rotation speed of the motor (rotor core 20) is less than 5000 (rpm).
  • the circumferential electromagnetic excitation force becomes a noise source during low-speed rotation
  • the radial electromagnetic excitation force becomes a noise source during high-speed rotation.
  • the maximum radial dimension L1 of the grooves 80A and 80B and the minimum dimension L2 of the circumferential interval between the grooves 80A and 80B satisfy 0.8 ⁇ (L2/L1) ⁇ 1.
  • FIG. 5 is a diagram showing the relationship between the rotation speed of the motor (rotor core 20) and the increase/decrease ratio of the twelfth radial electromagnetic excitation force.
  • the increase/decrease ratio of the radial electromagnetic excitation force of the twelfth electrical angle in the rotating electrical machine having the above-described grooves 80A and 80B is The increase/decrease ratio of the twelfth electrical angle radial electromagnetic excitation force is shown as "two grooves". As shown in FIG. 8, "one groove" in FIG.
  • the groove portion 80A and the groove portion 80B of "two grooves" satisfy the relationship of 0.8 ⁇ (L2/L1) ⁇ 1.2.
  • FIG. 6 is a diagram showing the relationship between the rotation speed of the motor (rotor core 20) and the increase/decrease ratio of the twelfth circumferential electromagnetic excitation force.
  • the increase/decrease ratio of the circumferential electromagnetic excitation force of twelfth electrical angle in the rotating electrical machine having the above-described grooves 80A and 80B is The increase/decrease ratio of the circumferential electromagnetic excitation force of the twelfth electrical angle is indicated as “two grooves", and the groove portion 80C is provided as "one groove” in a rotating electric machine. is shown.
  • the groove portion 80A and the groove portion 80B of "two grooves" satisfy the relationship of 0.8 ⁇ (L2/L1) ⁇ 1.2.
  • both the "two grooves” provided with the grooves 80A and 80B and the “single groove” provided with the grooves 80C rotate at a higher speed than the rotating electric machine without the grooves 80. It is possible to reduce the radial electromagnetic excitation force.
  • the circumferential electromagnetic excitation force during low-speed rotation is equivalent to that of the rotary electric machine in which the grooves 80 are not provided.
  • the circumferential electromagnetic excitation force during low-speed rotation increased as compared to the rotating electric machine in which the groove portion 80 was not provided.
  • the groove 80A and the groove 80B satisfy the relationship 0.8 ⁇ (L2/L1) ⁇ 1.2, so that the circumferential electromagnetic excitation force during low-speed rotation is reduced by the groove 80. It was equivalent to the rotary electric machine without the grooves 80, and the radial electromagnetic excitation force during high-speed rotation could be reduced more than the rotary electric machine without the grooves 80.
  • FIG. 1 is equivalent to the rotary electric machine without the grooves 80, and the radial electromagnetic excitation force during high-speed rotation could be reduced more than the rotary electric machine without the grooves 80.
  • the groove portion 80A has first linear portions 81 and 82, a second linear portion 83, and curved portions 84 and 85 when viewed in the axial direction.
  • the first linear portions 81 and 82 linearly extend radially inward from the outer peripheral surface 20a.
  • the first straight portion 81 is further from the q-axis IL2 than the first straight portion 82 in the circumferential direction.
  • the first linear portion 82 is closer to the q-axis IL2 than the first linear portion 81 in the circumferential direction.
  • the second straight portion 83 is positioned radially inward of the first straight portions 81 and 82 and extends linearly in the circumferential direction.
  • the curved portion 84 has an arc shape and connects the first straight portion 81 and the second straight portion 83 .
  • the curved portion 85 has an arc shape and connects the first straight portion 82 and the second straight portion 83 .
  • the arc-shaped curved portion 84 connects the first straight portion 81 and the second straight portion 83, thereby reducing the stress concentration at the intersection of the first straight portion 81 and the second straight portion 83. can be mitigated.
  • the arc-shaped curved portion 85 connects the first straight portion 82 and the second straight portion 83, thereby reducing the stress concentration at the intersection of the first straight portion 82 and the second straight portion 83. can be mitigated.
  • the circumferential distance from the farthest point from the q-axis IL2 (the radially outer end portion of the first straight portion 81) is the distance between the radially outer flux barrier portion 51d and the q-axis IL2. Shorter than the shortest circumferential distance.
  • the circumferential distance to the farthest point from the q-axis IL2 in the groove portion 80B is shorter than the circumferential shortest distance between the q-axis IL2 and the flux barrier portion 51b positioned radially outward.
  • the circumferential distance to the furthest point from the q-axis IL2 is shorter than the circumferential shortest distance between the q-axis IL2 and the flux barrier portion 51d located radially outward. It is possible to prevent the magnetic path between the flux barrier portion 51d from narrowing and the flow of the magnetic flux from being obstructed, thereby reducing the average torque.
  • the circumferential distance to the furthest point from the q-axis IL2 is shorter than the circumferential shortest distance between the q-axis IL2 and the flux barrier portion 51b located radially outward. It is possible to prevent the magnetic path between the flux barrier portion 51b from being narrowed and the flow of magnetic flux from being obstructed, thereby reducing the average torque.
  • FIG. 7 is a diagram showing the relationship between the number of grooves and the increase/decrease ratio of the average torque, and the relationship between the number of grooves and the increase/decrease ratio of the electromagnetic excitation force of 12th electrical angle.
  • the rotary electric machine without the groove portion 80 is indicated as "no groove”.
  • "one groove” indicates a rotary electric machine having a groove portion 80C with a maximum radial dimension L1 of 1.0 mm and a circumferential groove width L3 of 4.0 mm.
  • Tro grooves have a maximum radial dimension L1 of 1.0 mm for the grooves 80A and 80B, a minimum distance L2 of the circumferential spacing between the grooves 80A and 80B of 1.0 mm, and a groove width in the circumferential direction of 1.0 mm.
  • a rotating electrical machine with L3 of 4.0 mm is shown.
  • the average torque is the same value with no big difference in any of the "no groove”, “one groove”, and “two groove” rotary electric machines.
  • the increase/decrease ratio of the radial electromagnetic excitation force of the 12th electrical angle can be reduced more than the rotating electric machine in which the groove portion 80 is not provided in both the “single groove” and the “two grooves” rotating electric machines.
  • Regarding the increase/decrease ratio of the twelfth electrical angle circumferential electromagnetic excitation force in the case of the rotating electric machine with "one groove”, it increases more than in the case of the rotating electric machine with "no grooves", and in the case of the rotating electric machine with "two grooves", It is less than that of a "grooveless" rotary electric machine.
  • FIG. 9 shows the groove width L3, the average torque, the twelfth electrical angle radial electromagnetic
  • FIG. 10 is a diagram showing the relationship between the excitation force and each increase/decrease ratio of the circumferential electromagnetic excitation force of twelfth electrical angle;
  • the maximum radial dimension L1 is fixed at 1.0 mm, and the radius of the arc-shaped curved portion is fixed at 1.0 mm.
  • the average torque increase/decrease ratio is the same value without a large difference regardless of the value of the groove width L3.
  • the increase/decrease ratio of the radial electromagnetic excitation force of the 12th electrical angle is between 2.0 and 4.0 mm. Reduce.
  • the increase/decrease ratio of the circumferential electromagnetic excitation force of the twelfth electrical angle increases as the value of the groove width L3 increases. For this reason, in the case of a rotating electric machine having "one groove", it is difficult to reduce the increase/decrease ratio of the circumferential electromagnetic excitation force of the twelfth electrical angle.
  • FIG. 10 shows the groove width L3, the average torque, and the electrical angle 12 in the rotating electric machine having the groove portion 80A and the groove portion 80B of the "two grooves" shown in FIG.
  • FIG. 5 is a diagram showing the relationship between the increase/decrease ratios of the secondary radial electromagnetic excitation force and the electrical angle twelfth circumferential electromagnetic excitation force.
  • the minimum dimension L2 of the circumferential interval between the grooves 80A and 80B is fixed at 1.0 mm
  • the maximum radial dimension L1 and the radius of the arc-shaped curved portion are fixed at 1.0 mm. .
  • the average torque increase/decrease ratio is the same value without a large difference regardless of the value of the groove width L3.
  • the increase/decrease ratio of the radial electromagnetic excitation force of the 12th electrical angle is between 2.0 and 4.0 mm. Reduce.
  • the increase/decrease ratio of the circumferential electromagnetic excitation force of the 12th order in electrical angle is as follows: When the value of the groove width L3 exceeds 2.5 mm and is 4.0 mm or less, it is lower than that of the "no groove” rotary electric machine.
  • the value of the groove width L3 is set to, for example, 3.0 mm or more and 4.0 mm or less, thereby reducing the increase/decrease ratio of the twelfth electrical angle circumferential electromagnetic excitation force. can.
  • FIG. 11 shows the circumferential distance L2 between the grooves 80A and 80B in the rotating electric machine having the grooves 80A and 80B of "two grooves", the average torque, the electric power
  • FIG. 10 is a diagram showing the relationship between the increase/decrease ratios of the angular twelfth order radial electromagnetic excitation force and the electrical angle twelfth order circumferential electromagnetic excitation force;
  • the groove width L3 is fixed at 2.0 mm
  • the maximum radial dimension L1 and the radius of the arc-shaped curved portion are fixed at 1.0 mm.
  • the increase/decrease ratio of the average torque is such that when the value of the circumferential interval L2 is between 0.2 and 1.2 mm, the circumferential interval L2 There is no big difference regardless of the value of , and the values are equivalent.
  • the increase/decrease ratio of the radial electromagnetic excitation force of the 12th electrical angle is the same as that of "no groove” rotation when the value of the circumferential interval L2 is between 0.2 and 1.2 mm. Less than electric.
  • the increase/decrease ratio of the twelfth-order circumferential electromagnetic excitation force in the electrical angle is "no groove” rotation when the value of the circumferential interval L2 is between 0.2 and 1.2 mm. Although it increases more than the electric machine, the increase ratio is the smallest when the value of the interval L2 in the circumferential direction is 1.0 mm. Therefore, in the case of a rotating electric machine having "two grooves", the increase/decrease ratio of the circumferential electromagnetic excitation force of the twelfth electrical angle can be suppressed by setting the value of the circumferential interval L2 to 1.0 mm, for example.
  • the rotating electrical machine 1 may have a configuration in which the magnet 40 does not have the second magnet 42 and the magnetic pole pieces are adjacent to the first magnets 41a and 41b arranged in a V shape.
  • the magnet 40 does not have the second magnet 42, and a plurality of sets (for example, two sets) of adjacent magnetic pole pieces are arranged in the first magnets 41a and 41b with an interval in the radial direction. It may be the rotary electric machine 1 .

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Abstract

One embodiment of the rotating electric machine according to the present invention comprises: a rotor rotatable about the central axis; and a stator located outside the rotor in the radial direction. The rotor has a rotor core having a plurality of housing holes and a plurality of magnets respectively housed in the plurality of housing holes. The stator has: a stator core having an annular core back surrounding the rotor core and a plurality of teeth extending inward in the radial direction from the core back and disposed side by side at intervals in the circumferential direction; and a plurality of coils attached to the stator core. The plurality of magnets constitute poles and are disposed in the circumferential direction with the q-axis interposed therebetween. The rotor core has a pair of groove portions spaced on both sides sandwiching the q-axis in the circumferential direction in the outer circumferential surface when viewed in the axial direction and hollowed inward in the radial direction. When the maximum dimension of the groove portions in the radial direction is denoted by L1 and the minimum dimension of the space between the pair of groove portions in the circumferential direction is denoted by L2, the relationship of 0.8 ≤ (L2/L1) ≤ 1.2 is satisfied.

Description

回転電機Rotating electric machine
　本発明は、回転電機に関する。 The present invention relates to rotating electric machines.
　ロータコアとロータコアに設けられた穴に配置された永久磁石とを備える埋込磁石同期モータ（ＩＰＭＳＭ）等の回転電機が知られている。この種の回転電機では、減磁対策として、溝や突起，スリット，孔等をロータコアに設けること、磁石自体の寸法および材質、磁石の温度変化対策等が採られている。例えば、特許文献１には、永久磁石がＶ形状に配置されるとともに、Ｖ形状を構成する二組の磁石部のそれぞれが、磁石内部の磁化方向が互いに交差する向きとなっている第１磁石部と第２磁石部とを配置することで磁石の減磁を抑制する回転電機が開示されている。 A rotary electric machine such as an interior permanent magnet synchronous motor (IPMSM) is known that includes a rotor core and permanent magnets arranged in holes provided in the rotor core. In this type of rotary electric machine, as countermeasures against demagnetization, grooves, protrusions, slits, holes, etc. are provided in the rotor core, the dimensions and materials of the magnets themselves, countermeasures against temperature changes of the magnets, and the like are taken. For example, Patent Document 1 discloses a first magnet in which permanent magnets are arranged in a V shape, and magnetization directions inside the magnets of each of two sets of magnet portions forming the V shape are directed to intersect each other. A rotary electric machine is disclosed in which demagnetization of a magnet is suppressed by arranging a portion and a second magnet portion.
　回転電機においては、低振動・低騒音化が要求されている。そのため、モータを励振するロータとステータと間に働く電磁加振力への寄与度が高いエアギャップ近傍の形状を変更する技術として、例えば、特許文献２には、ロータコアの外周面に径方向内側に窪んだ溝を設けることが開示されている。特許文献２に記載された回転電機では、ロータコアの外周面に溝を設けることでステータとのエアギャップが大きくなり、周方向の電磁加振力を低減できる。 　In rotating electric machines, low vibration and low noise are required. Therefore, as a technique for changing the shape of the vicinity of the air gap that highly contributes to the electromagnetic excitation force acting between the rotor and the stator that excites the motor, for example, Patent Document 2 discloses a radially inner portion on the outer peripheral surface of the rotor core. It is disclosed to provide a recessed groove in the . In the rotary electric machine disclosed in Patent Document 2, the provision of grooves on the outer peripheral surface of the rotor core increases the air gap between the rotor core and the stator, thereby reducing the electromagnetic excitation force in the circumferential direction.
特開２０１９－３０２０６号公報Japanese Patent Application Laid-Open No. 2019-30206 特開２００９－２１３２５６号公報JP 2009-213256 A
　上記の回転電機では、モータの用途によっては駆動範囲が広く、モータの回転数が増えるほど、誘起電圧を低減するためにｄ軸電流を多く流すことがある。この場合、モータにおけるｄ軸磁束とｑ軸磁束のバランス関係も大きく変化し、モータを励振する電磁加振力も大きく変化する。例えば、モータは、低速時に周方向の電磁加振力が騒音源となり、高速時に径方向の電磁加振力が騒音源となる。そのため、１つのモータ形状で周方向と径方向の異なる成分の電磁加振力に対応する必要があるが、特許文献２に記載された溝は、低速時および高速時における電磁加振力を十分に考慮したものとは言えない。 In the rotating electric machine described above, depending on the application of the motor, the drive range is wide, and as the number of revolutions of the motor increases, more d-axis current may flow in order to reduce the induced voltage. In this case, the balance relationship between the d-axis magnetic flux and the q-axis magnetic flux in the motor also changes significantly, and the electromagnetic excitation force that excites the motor also changes significantly. For example, in a motor, a circumferential electromagnetic excitation force becomes a noise source at low speed, and a radial electromagnetic excitation force becomes a noise source at high speed. Therefore, it is necessary to deal with different components of the electromagnetic excitation force in the circumferential direction and the radial direction with one motor shape. cannot be said to have been taken into consideration.
　本発明は、以上のような点を考慮してなされたもので、モータの回転数に依らず騒音を低減できる回転電機を提供することを目的とする。 The present invention has been made in consideration of the above points, and an object of the present invention is to provide a rotating electric machine that can reduce noise regardless of the number of revolutions of the motor.
　本発明の回転電機の一つの態様は、中心軸を中心として回転可能なロータと、前記ロータの径方向外側に位置するステータと、を備え、前記ロータは、複数の収容穴を有するロータコアと、前記複数の収容穴の内部にそれぞれ収容された複数のマグネットと、を有し、前記ステータは、前記ロータコアを囲む環状のコアバック、および前記コアバックから径方向内側に延び周方向に間隔を空けて並んで配置された複数のティースを有するステータコアと、前記ステータコアに取り付けられた複数のコイルと、を有し、前記複数のマグネットは、極を構成し、ｑ軸を介して前記周方向に複数配置され、前記ロータコアは、軸方向に見て外周面における前記ｑ軸を挟んだ周方向の両側に間隔をあけて、径方向内側に窪んだ一対の溝部をそれぞれ有し、前記溝部の径方向の最大寸法をＬ１とし、一対の前記溝部同士の周方向の間隔の最小寸法をＬ２とすると、０．８≦（Ｌ２／Ｌ１）≦１．２の関係を満足する。 One aspect of the rotating electrical machine of the present invention includes a rotor rotatable about a central axis, and a stator positioned radially outward of the rotor, the rotor including a rotor core having a plurality of housing holes; and a plurality of magnets respectively housed within the plurality of housing holes, wherein the stator includes an annular core-back surrounding the rotor core, and a stator extending radially inward from the core-back and spaced circumferentially from the core-back. a stator core having a plurality of teeth arranged side by side; and a plurality of coils attached to the stator core. The rotor core has a pair of grooves recessed radially inward at intervals on both sides in the circumferential direction of the outer peripheral surface of the rotor core across the q-axis when viewed in the axial direction. L1 is the maximum dimension of the grooves, and L2 is the minimum dimension of the interval between the pair of grooves in the circumferential direction.
　本発明の一つの態様によれば、回転電機においてモータの回転数に依らず騒音を低減できる。 According to one aspect of the present invention, noise can be reduced in a rotating electric machine regardless of the number of revolutions of the motor.
図１は、本実施形態の回転電機を示す断面図である。FIG. 1 is a cross-sectional view showing a rotating electrical machine of this embodiment. 図２は、本実施形態の回転電機の一部を示す断面図であって、図１におけるII－II断面図である。FIG. 2 is a cross-sectional view showing a part of the rotating electric machine of this embodiment, taken along the line II--II in FIG. 図３は、本実施形態のロータの磁極部およびステータコアの一部を示す断面図である。FIG. 3 is a sectional view showing the magnetic pole portions of the rotor and part of the stator core of the present embodiment. 図４は、ティース６６Ｆと径方向に対向する溝部の周辺を拡大した断面図である。FIG. 4 is an enlarged cross-sectional view of the periphery of the groove facing the teeth 66F in the radial direction. 図５は、モータの回転数と、１２次径方向電磁加振力の増減比との関係を示す図である。FIG. 5 is a diagram showing the relationship between the number of revolutions of the motor and the increase/decrease ratio of the 12th order radial electromagnetic excitation force. 図６は、モータの回転数と、１２次周方向電磁加振力の増減比との関係を示す図である。FIG. 6 is a diagram showing the relationship between the number of rotations of the motor and the increase/decrease ratio of the twelfth circumferential electromagnetic excitation force. 図７は、溝部の数と平均トルクの増減比との関係を示すとともに、溝部の数と電気角１２次電磁加振力の増減比との関係を示す図である。FIG. 7 is a diagram showing the relationship between the number of grooves and the increase/decrease ratio of the average torque, and the relationship between the number of grooves and the increase/decrease ratio of the electromagnetic excitation force of 12th electrical angle. 図８は、「溝１つ」を有する回転電機の溝部の周辺を拡大した断面図である。FIG. 8 is an enlarged cross-sectional view of the periphery of a groove portion of a rotating electric machine having "one groove". 図９は、溝部が設けられない回転電機に対して、溝部８０Ｃを有する回転電機における、溝幅Ｌ３と、平均トルク、電気角１２次径方向電磁加振力および電気角１２次周方向電磁加振力の各増減比との関係を示す図である。FIG. 9 shows the groove width L3, the average torque, the radial electromagnetic excitation force of the twelfth electrical angle, and the circumferential electromagnetic force of the twelfth electrical angle in the rotating electrical machine having the groove 80C, as compared with the rotating electrical machine having no groove. It is a figure which shows the relationship with each increase-and-decrease ratio of vibration force. 図１０は、溝幅Ｌ３と、平均トルク、電気角１２次径方向電磁加振力および電気角１２次周方向電磁加振力の各増減比との関係を示す図である。FIG. 10 is a diagram showing the relationship between the groove width L3 and the increase/decrease ratio of the average torque, the radial electromagnetic excitation force of the 12th electrical angle, and the circumferential electromagnetic excitation force of the 12th electrical angle. 図１１は、溝部同士の周方向の間隔の最小寸法Ｌ２と、平均トルク、電気角１２次径方向電磁加振力および電気角１２次周方向電磁加振力の各増減比との関係を示す図である。FIG. 11 shows the relationship between the minimum dimension L2 of the circumferential interval between the grooves and the ratio of increase/decrease of the average torque, radial electromagnetic excitation force of 12th electrical angle, and circumferential electromagnetic excitation force of 12th electrical angle. It is a diagram.
　以下、図面を参照しながら、本発明の実施形態に係る回転電機について説明する。なお、本発明の範囲は、以下の実施の形態に限定されず、本発明の技術的思想の範囲内で任意に変更可能である。また、以下の図面においては、各構成をわかりやすくするために、実際の構造と各構造における縮尺や数等を異ならせる場合がある。 A rotating electrical machine according to an embodiment of the present invention will be described below with reference to the drawings. It should be noted that the scope of the present invention is not limited to the following embodiments, and can be arbitrarily changed within the scope of the technical idea of the present invention. Also, in the drawings below, in order to make each configuration easier to understand, there are cases where the actual structure and the scale, number, etc. of each structure are different.
　各図に適宜示すＺ軸方向は、正の側を「上側」とし、負の側を「下側」とする上下方向である。各図に適宜示す中心軸Ｊは、Ｚ軸方向と平行であり、上下方向に延びる仮想線である。以下の説明においては、中心軸Ｊの軸方向、すなわち上下方向と平行な方向を単に「軸方向」と呼び、中心軸Ｊを中心とする径方向を単に「径方向」と呼び、中心軸Ｊを中心とする周方向を単に「周方向」と呼ぶ。各図に適宜示す矢印θは、周方向を示している。矢印θは、上側から見て中心軸Ｊを中心として時計回りの向きを向いている。以下の説明では、或る対象を基準として周方向のうち矢印θが向かう側、すなわち上側から見て時計回りに進む側を「周方向一方側」と呼び、或る対象を基準として周方向のうち矢印θが向かう側と逆側、すなわち上側から見て反時計回りに進む側を「周方向他方側」と呼ぶ。 The Z-axis direction shown as appropriate in each figure is a vertical direction in which the positive side is the "upper side" and the negative side is the "lower side." A central axis J appropriately shown in each figure is a virtual line parallel to the Z-axis direction and extending in the vertical direction. In the following description, the axial direction of the central axis J, that is, the direction parallel to the vertical direction is simply referred to as the "axial direction", the radial direction around the central axis J is simply referred to as the "radial direction", and the central axis J is simply referred to as the "circumferential direction". An arrow θ appropriately shown in each figure indicates the circumferential direction. The arrow θ points clockwise around the central axis J when viewed from above. In the following description, of the circumferential direction with a certain object as a reference, the side toward which the arrow θ is directed, that is, the side proceeding clockwise when viewed from the upper side will be referred to as "one side in the circumferential direction". Of these, the side opposite to the direction of the arrow θ, that is, the side proceeding counterclockwise when viewed from above is called the “other side in the circumferential direction”.
　なお、上下方向、上側、および下側とは、単に各部の配置関係等を説明するための名称であり、実際の配置関係等は、これらの名称で示される配置関係等以外の配置関係等であってもよい。 It should be noted that the vertical direction, upper side, and lower side are simply names for explaining the arrangement relationship of each part, and the actual arrangement relationship is not the arrangement relationship indicated by these names. There may be.
　図１に示すように、本実施形態の回転電機１は、インナーロータ型の回転電機である。
　本実施形態において回転電機１は、三相交流式の回転電機である。回転電機１は、例えば、三相交流の電源が供給されることで駆動される三相モータである。回転電機１は、ハウジング２と、ロータ１０と、ステータ６０と、ベアリングホルダ４と、ベアリング５ａ，５ｂと、を備える。 As shown in FIG. 1, the rotating electrical machine 1 of this embodiment is an inner rotor type rotating electrical machine.
In this embodiment, the rotating electrical machine 1 is a three-phase AC rotating electrical machine. The rotary electric machine 1 is, for example, a three-phase motor that is driven by being supplied with three-phase AC power. The rotating electric machine 1 includes a housing 2, a rotor 10, a stator 60, a bearing holder 4, and bearings 5a and 5b.
　ハウジング２は、ロータ１０、ステータ６０、ベアリングホルダ４、およびベアリング５ａ，５ｂを内部に収容している。ハウジング２の底部は、ベアリング５ｂを保持している。ベアリングホルダ４は、ベアリング５ａを保持している。ベアリング５ａ，５ｂは、例えば、ボールベアリングである。 The housing 2 accommodates the rotor 10, the stator 60, the bearing holder 4, and the bearings 5a and 5b inside. The bottom of housing 2 holds a bearing 5b. A bearing holder 4 holds a bearing 5a. The bearings 5a, 5b are, for example, ball bearings.
　ステータ６０は、ロータ１０の径方向外側に位置する。ステータ６０は、ステータコア６１と、インシュレータ６４と、複数のコイル６５と、を有する。ステータコア６１は、コアバック６２と、複数のティース６３と、を有する。コアバック６２は、後述するロータコア２０の径方向外側に位置する。図２に示すように、コアバック６２は、ロータコア２０を囲む環状である。コアバック６２は、例えば、中心軸Ｊを中心とする円環状である。 The stator 60 is located radially outside the rotor 10 . The stator 60 has a stator core 61 , insulators 64 and multiple coils 65 . Stator core 61 has a core back 62 and a plurality of teeth 63 . The core back 62 is located radially outside the rotor core 20, which will be described later. As shown in FIG. 2 , core back 62 has an annular shape surrounding rotor core 20 . The core back 62 has an annular shape centering on the central axis J, for example.
　複数のティース６３は、コアバック６２から径方向内側に延びている。複数のティース６３は、周方向に間隔を空けて並んで配置されている。複数のティース６３は、例えば、周方向に沿って一周に亘って等間隔に配置されている。ティース６３は、例えば、４８個設けられている。つまり、回転電機１のスロット６７の数は、例えば、４８である。図３および図４に示すように、複数のティース６３は、基部６３ａと、アンブレラ部６３ｂと、をそれぞれ有する。 A plurality of teeth 63 extend radially inward from the core back 62 . The plurality of teeth 63 are arranged side by side at intervals in the circumferential direction. The multiple teeth 63 are, for example, arranged at regular intervals along the circumferential direction. For example, 48 teeth 63 are provided. That is, the number of slots 67 of the rotating electric machine 1 is 48, for example. As shown in FIGS. 3 and 4, each of the teeth 63 has a base portion 63a and an umbrella portion 63b.
　基部６３ａは、コアバック６２から径方向内側に延びている。基部６３ａの周方向の寸法は、例えば、径方向の全体に亘って同じである。なお、基部６３ａの周方向の寸法は、例えば、径方向内側に向かうに従って小さくなっていてもよい。 The base portion 63 a extends radially inward from the core back 62 . The circumferential dimension of the base portion 63a is, for example, the same throughout the radial direction. Note that the circumferential dimension of the base portion 63a may decrease, for example, toward the radially inner side.
　アンブレラ部６３ｂは、基部６３ａの径方向内側の端部に設けられている。アンブレラ部６３ｂは、基部６３ａよりも周方向の両側に突出している。アンブレラ部６３ｂの周方向の寸法は、基部６３ａの径方向内側の端部における周方向の寸法よりも大きい。アンブレラ部６３ｂの径方向内側の面は、周方向に沿った曲面である。アンブレラ部６３ｂの径方向内側の面は、軸方向に見て、中心軸Ｊを中心とする円弧状に延びている。アンブレラ部６３ｂの径方向内側の面は、後述するロータコア２０の外周面と径方向に隙間を介して対向している。周方向に隣り合うティース６３同士において、アンブレラ部６３ｂ同士は、周方向に隙間を介して並んで配置されている。 The umbrella portion 63b is provided at the radially inner end portion of the base portion 63a. The umbrella portion 63b protrudes to both sides in the circumferential direction from the base portion 63a. The circumferential dimension of the umbrella portion 63b is greater than the circumferential dimension of the radially inner end portion of the base portion 63a. A radially inner surface of the umbrella portion 63b is a curved surface along the circumferential direction. A radially inner surface of the umbrella portion 63b extends in an arc around the central axis J when viewed in the axial direction. The radially inner surface of the umbrella portion 63b faces the outer peripheral surface of the rotor core 20 to be described later with a gap in the radial direction. Umbrella portions 63b of teeth 63 adjacent to each other in the circumferential direction are arranged side by side with a gap in the circumferential direction.
　複数のコイル６５は、ステータコア６１に取り付けられている。図１に示すように、複数のコイル６５は、例えば、インシュレータ６４を介してティース６３に取り付けられている。本実施形態においてコイル６５は、分布巻きされている。つまり、各コイル６５は、複数のティース６３に跨って巻き回されている。本実施形態においてコイル６５は、全節巻きされている。つまり、コイル６５が差し込まれるステータ６０のスロット同士の周方向ピッチが、ステータ６０に三相交流電源が供給された際に生じる磁極の周方向ピッチと等しい。回転電機１の極数は、例えば、８である。つまり、回転電機１は、例えば、８極４８スロットの回転電機である。このように、本実施形態の回転電機１においては、極数をＮとしたとき、スロット数がＮ×６となる。なお、図２～図３においては、インシュレータ６４の図示を省略している。 A plurality of coils 65 are attached to the stator core 61 . As shown in FIG. 1, the plurality of coils 65 are attached to the teeth 63 via insulators 64, for example. In this embodiment, the coil 65 is distributed winding. That is, each coil 65 is wound over a plurality of teeth 63 . In this embodiment, the coil 65 is wound in full pitch. That is, the circumferential pitch between the slots of the stator 60 into which the coils 65 are inserted is equal to the circumferential pitch of the magnetic poles generated when the stator 60 is supplied with the three-phase AC power. The number of poles of the rotary electric machine 1 is eight, for example. That is, the rotary electric machine 1 is, for example, an 8-pole 48-slot rotary electric machine. Thus, in the rotary electric machine 1 of this embodiment, when the number of poles is N, the number of slots is N×6. 2 and 3, illustration of the insulator 64 is omitted.
　ロータ１０は、中心軸Ｊを中心として回転可能である。図２に示すように、ロータ１０は、シャフト１１と、ロータコア２０と、複数のマグネット４０と、を有する。シャフト１１は、中心軸Ｊを中心として軸方向に延びる円柱状である。図１に示すように、シャフト１１は、ベアリング５ａ，５ｂによって中心軸Ｊ回りに回転可能に支持されている。 The rotor 10 is rotatable around the central axis J. As shown in FIG. 2 , the rotor 10 has a shaft 11 , a rotor core 20 and a plurality of magnets 40 . The shaft 11 has a columnar shape extending in the axial direction around the central axis J. As shown in FIG. As shown in FIG. 1, the shaft 11 is rotatably supported around a central axis J by bearings 5a and 5b.
　ロータコア２０は、磁性体である。ロータコア２０は、シャフト１１の外周面に固定されている。ロータコア２０は、ロータコア２０を軸方向に貫通する貫通孔２１を有する。図２に示すように、貫通孔２１は、軸方向に見て、中心軸Ｊを中心とする円形状である。貫通孔２１には、シャフト１１が通されている。シャフト１１は、例えば圧入等により、貫通孔２１内に固定されている。図示は省略するが、ロータコア２０は、例えば、複数の電磁鋼板が軸方向に積層されて構成されている。 The rotor core 20 is a magnetic material. Rotor core 20 is fixed to the outer peripheral surface of shaft 11 . Rotor core 20 has a through hole 21 that axially penetrates rotor core 20 . As shown in FIG. 2, the through hole 21 has a circular shape centered on the central axis J when viewed in the axial direction. The shaft 11 is passed through the through hole 21 . The shaft 11 is fixed in the through hole 21 by, for example, press fitting. Although illustration is omitted, the rotor core 20 is configured, for example, by laminating a plurality of electromagnetic steel sheets in the axial direction.
　ロータコア２０は、複数の収容穴３０を有する。複数の収容穴３０は、例えば、ロータコア２０を軸方向に貫通している。複数の収容穴３０の内部には、複数のマグネット４０がそれぞれ収容されている。収容穴３０内におけるマグネット４０の固定方法は、特に限定されない。複数の収容穴３０は、一対の第１収容穴３１ａ，３１ｂと、第２収容穴３２と、を含む。 The rotor core 20 has a plurality of accommodation holes 30. The plurality of housing holes 30 , for example, penetrate the rotor core 20 in the axial direction. A plurality of magnets 40 are housed inside the plurality of housing holes 30, respectively. A method for fixing the magnet 40 in the accommodation hole 30 is not particularly limited. The multiple accommodation holes 30 include a pair of first accommodation holes 31 a and 31 b and a second accommodation hole 32 .
　複数のマグネット４０の種類は、特に限定されない。マグネット４０は、例えば、ネオジム磁石であってもよいし、フェライト磁石であってもよい。複数のマグネット４０は、一対の第１マグネット４１ａ，４１ｂと、第２マグネット４２と、を含む。一対の第１マグネット４１ａ，４１ｂと、第２マグネット４２とは極を構成する。 The types of the plurality of magnets 40 are not particularly limited. The magnet 40 may be, for example, a neodymium magnet or a ferrite magnet. The multiple magnets 40 include a pair of first magnets 41 a and 41 b and a second magnet 42 . The pair of first magnets 41a and 41b and the second magnet 42 form poles.
　本実施形態において一対の第１収容穴３１ａ，３１ｂと一対の第１マグネット４１ａ，４１ｂと第２収容穴３２と第２マグネット４２とは、周方向に間隔を空けて複数ずつ設けられている。一対の第１収容穴３１ａ，３１ｂと一対の第１マグネット４１ａ，４１ｂと第２収容穴３２と第２マグネット４２とは、例えば、８つずつ設けられている。 In the present embodiment, the pair of first accommodation holes 31a, 31b, the pair of first magnets 41a, 41b, the second accommodation holes 32, and the second magnets 42 are provided at intervals in the circumferential direction. The pair of first accommodation holes 31a, 31b, the pair of first magnets 41a, 41b, the second accommodation holes 32, and the second magnets 42 are provided, for example, eight each.
　ロータ１０は、一対の第１収容穴３１ａ，３１ｂと一対の第１マグネット４１ａ，４１ｂと第２収容穴３２と第２マグネット４２とを１つずつ含む磁極部７０を複数有する。磁極部７０は、例えば、８つ設けられている。複数の磁極部７０は、例えば、周方向に沿って一周に亘って等間隔に配置されている。複数の磁極部７０は、ロータコア２０の外周面における磁極がＮ極の磁極部７０Ｎと、ロータコア２０の外周面における磁極がＳ極の磁極部７０Ｓと、を複数ずつ含む。磁極部７０Ｎと磁極部７０Ｓとは、例えば、４つずつ設けられている。４つの磁極部７０Ｎと４つの磁極部７０Ｓとは、周方向に沿って交互に配置されている。各磁極部７０の構成は、ロータコア２０の外周面の磁極が異なる点および周方向位置が異なる点を除いて、同様の構成である。 The rotor 10 has a plurality of magnetic pole portions 70 each including a pair of first housing holes 31a, 31b, a pair of first magnets 41a, 41b, a second housing hole 32, and a second magnet 42. For example, eight magnetic pole portions 70 are provided. The plurality of magnetic pole portions 70 are, for example, arranged at regular intervals along the circumferential direction. The plurality of magnetic pole portions 70 include a plurality of magnetic pole portions 70N having N-pole magnetic poles on the outer peripheral surface of the rotor core 20 and a plurality of magnetic pole portions 70S having S-pole magnetic poles on the outer peripheral surface of the rotor core 20, respectively. For example, four magnetic pole portions 70N and four magnetic pole portions 70S are provided. The four magnetic pole portions 70N and the four magnetic pole portions 70S are alternately arranged along the circumferential direction. The configuration of each magnetic pole portion 70 is the same except that the magnetic poles on the outer peripheral surface of the rotor core 20 are different and the positions in the circumferential direction are different.
　図３に示すように、磁極部７０において、一対の第１収容穴３１ａ，３１ｂは、周方向に互いに間隔を空けて配置されている。第１収容穴３１ａは、例えば、第１収容穴３１ｂの周方向一方側（＋θ側）に位置する。第１収容穴３１ａ，３１ｂは、例えば、軸方向に見て、径方向に対して斜めに傾いた方向に略直線状に延びている。一対の第１収容穴３１ａ，３１ｂは、軸方向に見て径方向内側から径方向外側に向かうに従って互いに周方向に離れる方向に延びている。つまり、第１収容穴３１ａと第１収容穴３１ｂとの間の周方向の距離は、径方向内側から径方向外側に向かうに従って大きくなっている。第１収容穴３１ａは、例えば、径方向内側から径方向外側に向かうに従って、周方向一方側に位置する。第１収容穴３１ｂは、例えば、径方向内側から径方向外側に向かうに従って、周方向他方側（－θ側）に位置する。第１収容穴３１ａ，３１ｂの径方向外側の端部は、ロータコア２０の径方向外周縁部に位置する。 As shown in FIG. 3, in the magnetic pole portion 70, the pair of first accommodation holes 31a and 31b are arranged with a space therebetween in the circumferential direction. The first accommodation hole 31a is positioned, for example, on one circumferential side (+θ side) of the first accommodation hole 31b. The first accommodation holes 31a and 31b extend substantially linearly in a direction oblique to the radial direction, for example, when viewed in the axial direction. The pair of first receiving holes 31a and 31b extend in directions away from each other in the circumferential direction as viewed in the axial direction from the radially inner side toward the radially outer side. That is, the circumferential distance between the first receiving holes 31a and 31b increases from the radially inner side to the radially outer side. The first accommodation hole 31a is located on one side in the circumferential direction, for example, from the radially inner side to the radially outer side. The first accommodation hole 31b is located, for example, on the other circumferential side (−θ side) from the radially inner side toward the radially outer side. The radially outer ends of the first accommodation holes 31 a and 31 b are positioned at the radially outer peripheral edge of the rotor core 20 .
　第１収容穴３１ａと第１収容穴３１ｂとは、例えば、軸方向に見て、ｄ軸を構成する図３に示す磁極中心線ＩＬ１を周方向に挟んで配置されている。磁極中心線ＩＬ１は、磁極部７０の周方向中心と中心軸Ｊとを通り、径方向に延びる仮想線である。第１収容穴３１ａと第１収容穴３１ｂとは、例えば、軸方向に見て、磁極中心線ＩＬ１に対して線対称に配置されている。以下、磁極中心線ＩＬ１に対して線対称である点を除いて第１収容穴３１ａと同様の構成については、第１収容穴３１ｂについての説明を省略する場合がある。 The first accommodation holes 31a and 31b are arranged, for example, in the axial direction so as to sandwich the magnetic pole center line IL1 shown in FIG. 3, which constitutes the d-axis, in the circumferential direction. The magnetic pole center line IL1 is a virtual line passing through the circumferential center of the magnetic pole portion 70 and the central axis J and extending in the radial direction. The first receiving holes 31a and the first receiving holes 31b are, for example, arranged line-symmetrically with respect to the magnetic pole center line IL1 when viewed in the axial direction. Hereinafter, description of the first receiving hole 31b may be omitted for the same configuration as the first receiving hole 31a except that it is line-symmetrical with respect to the magnetic pole center line IL1.
　第１収容穴３１ａは、第１直線部３１ｃと、内端部３１ｄと、外端部３１ｅと、を有する。第１直線部３１ｃは、軸方向に見て、第１収容穴３１ａが延びる方向に直線状に延びている。第１直線部３１ｃは、例えば、軸方向に見て長方形状である。内端部３１ｄは、第１直線部３１ｃの径方向内側の端部に繋がっている。内端部３１ｄは、第１収容穴３１ａの径方向内側の端部である。外端部３１ｅは、第１直線部３１ｃの径方向外側の端部に繋がっている。外端部３１ｅは、第１収容穴３１ａの径方向外側の端部である。第１収容穴３１ｂは、第１直線部３１ｆと、内端部３１ｇと、外端部３１ｈと、を有する。 The first accommodation hole 31a has a first linear portion 31c, an inner end portion 31d, and an outer end portion 31e. The first linear portion 31c linearly extends in the direction in which the first receiving hole 31a extends when viewed in the axial direction. The first linear portion 31c has, for example, a rectangular shape when viewed in the axial direction. The inner end portion 31d is connected to the radially inner end portion of the first straight portion 31c. The inner end portion 31d is a radially inner end portion of the first receiving hole 31a. The outer end portion 31e is connected to the radially outer end portion of the first straight portion 31c. The outer end portion 31e is a radially outer end portion of the first accommodation hole 31a. The first accommodation hole 31b has a first linear portion 31f, an inner end portion 31g, and an outer end portion 31h.
　第２収容穴３２は、一対の第１収容穴３１ａ，３１ｂの径方向外側の端部同士の周方向の間に位置する。つまり、本実施形態において第２収容穴３２は、外端部３１ｅと外端部３１ｈとの周方向の間に位置する。第２収容穴３２は、例えば、軸方向に見て、径方向と直交する方向に略直線状に延びている。第２収容穴３２は、例えば、軸方向に見て、磁極中心線ＩＬ１と直交する方向に延びている。一対の第１収容穴３１ａ，３１ｂと第２収容穴３２とは、例えば、軸方向に見て、∇形状に沿って配置されている。 The second accommodation hole 32 is located between the radial outer ends of the pair of first accommodation holes 31a and 31b in the circumferential direction. That is, in the present embodiment, the second accommodation hole 32 is located between the outer end portion 31e and the outer end portion 31h in the circumferential direction. The second receiving hole 32 extends substantially linearly in a direction orthogonal to the radial direction, for example, when viewed in the axial direction. The second receiving hole 32 extends, for example, in a direction orthogonal to the magnetic pole center line IL1 when viewed in the axial direction. The pair of first receiving holes 31a and 31b and the second receiving hole 32 are arranged, for example, along a ∇ shape when viewed in the axial direction.
　なお、本明細書において「或る対象が或る方向と直交する方向に延びる」とは、或る対象が、或る方向と厳密に直交する方向に延びる場合に加えて、或る対象が、或る方向と略直交する方向に延びる場合も含む。「或る方向と略直交する方向」とは、例えば、製造時の公差等によって、或る方向と厳密に直交する方向に対して数度［°］程度の範囲内で傾いた方向を含む。 In addition, in this specification, "a certain object extends in a direction orthogonal to a certain direction" means that a certain object extends in a direction strictly orthogonal to a certain direction, and in addition, a certain object It also includes the case where it extends in a direction substantially orthogonal to a certain direction. "A direction substantially orthogonal to a certain direction" includes, for example, a direction inclined within a range of several degrees [°] with respect to a direction strictly orthogonal to a certain direction due to manufacturing tolerances or the like.
　軸方向に見て、第２収容穴３２の周方向の中心には、例えば、磁極中心線ＩＬ１が通っている。つまり、第２収容穴３２の周方向中心の周方向位置は、例えば、磁極部７０の周方向中心の周方向位置と一致している。第２収容穴３２の軸方向に見た形状は、例えば、磁極中心線ＩＬ１を中心とする線対称な形状である。第２収容穴３２は、ロータコア２０の径方向外周縁部に位置する。 When viewed in the axial direction, for example, the magnetic pole center line IL1 passes through the center of the second housing hole 32 in the circumferential direction. That is, the circumferential position of the circumferential center of the second housing hole 32 coincides with, for example, the circumferential position of the magnetic pole portion 70 . The shape of the second housing hole 32 when viewed in the axial direction is, for example, a line-symmetrical shape about the magnetic pole center line IL1. The second accommodation hole 32 is positioned at the radially outer peripheral edge of the rotor core 20 .
　第２収容穴３２は、第２直線部３２ａと、一端部３２ｂと、他端部３２ｃと、を有する。第２直線部３２ａは、軸方向に見て、第２収容穴３２が延びる方向に直線状に延びている。第２直線部３２ａは、例えば、軸方向に見て長方形状である。一端部３２ｂは、第２直線部３２ａの周方向一方側（＋θ側）の端部に繋がっている。一端部３２ｂは、第２収容穴３２の周方向一方側の端部である。一端部３２ｂは、第１収容穴３１ａにおける外端部３１ｅの周方向他方側（－θ側）に間隔を空けて配置されている。他端部３２ｃは、第２直線部３２ａの周方向他方側（－θ側）の端部に繋がっている。他端部３２ｃは、第２収容穴３２の周方向他方側の端部である。他端部３２ｃは、第１収容穴３１ｂにおける外端部３１ｈの周方向一方側に間隔を空けて配置されている。 The second accommodation hole 32 has a second linear portion 32a, one end portion 32b, and the other end portion 32c. The second linear portion 32a linearly extends in the direction in which the second receiving hole 32 extends when viewed in the axial direction. The second linear portion 32a has, for example, a rectangular shape when viewed in the axial direction. The one end portion 32b is connected to the end portion on one circumferential side (+θ side) of the second linear portion 32a. The one end portion 32b is an end portion on one side in the circumferential direction of the second accommodation hole 32 . The one end portion 32b is spaced apart from the outer end portion 31e of the first accommodating hole 31a in the circumferential direction (−θ side). The other end 32c is connected to the end of the second linear portion 32a on the other circumferential side (−θ side). The other end 32c is the end of the second receiving hole 32 on the other side in the circumferential direction. The other end portion 32c is arranged on one circumferential side of the outer end portion 31h of the first accommodation hole 31b with a space therebetween.
　一対の第１マグネット４１ａ，４１ｂは、一対の第１収容穴３１ａ，３１ｂの内部にそれぞれ収容されている。第１マグネット４１ａは、第１収容穴３１ａの内部に収容されている。第１マグネット４１ｂは、第１収容穴３１ｂの内部に収容されている。一対の第１マグネット４１ａ，４１ｂは、例えば、軸方向に見て長方形状である。一対の第１マグネット４１ａ，４１ｂが延びる方向の長さは同じである。一対の第１マグネット４１ａ，４１ｂが延びる方向と直交する方向の第１マグネット４１ａ，４１ｂの長さは同じである。 The pair of first magnets 41a and 41b are housed inside the pair of first housing holes 31a and 31b, respectively. The first magnet 41a is housed inside the first housing hole 31a. The first magnet 41b is housed inside the first housing hole 31b. The pair of first magnets 41a and 41b has, for example, a rectangular shape when viewed in the axial direction. The lengths in the direction in which the pair of first magnets 41a and 41b extend are the same. The lengths of the first magnets 41a and 41b in the direction orthogonal to the direction in which the pair of first magnets 41a and 41b extend are the same.
　図示は省略するが、第１マグネット４１ａ，４１ｂは、例えば、直方体状である。図示は省略するが、第１マグネット４１ａ，４１ｂは、例えば、第１収容穴３１ａ，３１ｂ内の軸方向の全体に亘って設けられている。一対の第１マグネット４１ａ，４１ｂは、周方向に互いに間隔を空けて配置されている。第１マグネット４１ａは、例えば、第１マグネット４１ｂの周方向一方側（＋θ側）に位置する。 Although not shown, the first magnets 41a and 41b are rectangular parallelepipeds, for example. Although not shown, the first magnets 41a and 41b are provided, for example, over the entirety of the first receiving holes 31a and 31b in the axial direction. The pair of first magnets 41a and 41b are arranged with a space therebetween in the circumferential direction. The first magnet 41a is positioned, for example, on one circumferential side (+θ side) of the first magnet 41b.
　第１マグネット４１ａは、軸方向に見て第１収容穴３１ａに沿って延びている。第１マグネット４１ｂは、軸方向に見て第１収容穴３１ｂに沿って延びている。第１マグネット４１ａ，４１ｂは、例えば、軸方向に見て、径方向に対して斜めに傾いた方向に略直線状に延びている。一対の第１マグネット４１ａ，４１ｂは、軸方向に見て径方向内側から径方向外側に向かうに従って互いに周方向に離れる方向に延びている。つまり、第１マグネット４１ａと第１マグネット４１ｂとの間の周方向の距離は、径方向内側から径方向外側に向かうに従って大きくなっている。 The first magnet 41a extends along the first receiving hole 31a when viewed in the axial direction. The first magnet 41b extends along the first receiving hole 31b when viewed in the axial direction. The first magnets 41a and 41b, for example, extend substantially linearly in a direction oblique to the radial direction when viewed in the axial direction. The pair of first magnets 41a and 41b extend in directions away from each other in the circumferential direction as viewed in the axial direction from the radially inner side toward the radially outer side. That is, the circumferential distance between the first magnets 41a and 41b increases from the radially inner side to the radially outer side.
　第１マグネット４１ａは、例えば、径方向内側から径方向外側に向かうに従って、周方向一方側（＋θ側）に位置する。第１マグネット４１ｂは、例えば、径方向内側から径方向外側に向かうに従って、周方向他方側（－θ側）に位置する。第１マグネット４１ａと第１マグネット４１ｂとは、例えば、軸方向に見て、磁極中心線ＩＬ１を周方向に挟んで配置されている。第１マグネット４１ａと第１マグネット４１ｂとは、例えば、軸方向に見て、磁極中心線ＩＬ１に対して線対称に配置されている。以下、磁極中心線ＩＬ１に対して線対称である点を除いて第１マグネット４１ａと同様の構成については、第１マグネット４１ｂについての説明を省略する場合がある。 The first magnet 41a is positioned, for example, on one circumferential side (+θ side) from the radially inner side to the radially outer side. The first magnet 41b is positioned, for example, on the other circumferential side (−θ side) from the radially inner side to the radially outer side. The first magnet 41a and the first magnet 41b are arranged, for example, so as to sandwich the magnetic pole center line IL1 in the circumferential direction when viewed in the axial direction. The first magnet 41a and the first magnet 41b are arranged line-symmetrically with respect to the magnetic pole center line IL1, for example, when viewed in the axial direction. Hereinafter, the description of the first magnet 41b may be omitted for the same configuration as the first magnet 41a except that it is line-symmetrical with respect to the magnetic pole center line IL1.
　第１マグネット４１ａは、第１収容穴３１ａ内に嵌め合わされている。より詳細には、第１マグネット４１ａは、第１直線部３１ｃ内に嵌め合わされている。第１マグネット４１ａの側面のうち、第１直線部３１ｃが延びる方向と直交する方向における両側面は、例えば、第１直線部３１ｃの内側面とそれぞれ接触している。軸方向に見て第１直線部３１ｃが延びる方向において、第１マグネット４１ａの長さは、例えば、第１直線部３１ｃの長さと同じである。 The first magnet 41a is fitted in the first accommodation hole 31a. More specifically, the first magnet 41a is fitted inside the first linear portion 31c. Of the side surfaces of the first magnet 41a, both side surfaces in the direction perpendicular to the direction in which the first straight portion 31c extends are in contact with the inner side surface of the first straight portion 31c, for example. In the direction in which the first linear portion 31c extends when viewed in the axial direction, the length of the first magnet 41a is, for example, the same as the length of the first linear portion 31c.
　軸方向に見て、第１マグネット４１ａの延伸方向の両端部は、第１収容穴３１ａの延伸方向の両端部からそれぞれ離れて配置されている。軸方向に見て、第１マグネット４１ａが延びる方向において第１マグネット４１ａの両側には、内端部３１ｄと外端部３１ｅとがそれぞれ隣接して配置されている。ここで、本実施形態において内端部３１ｄは、第１フラックスバリア部５１ａを構成している。外端部３１ｅは、第１フラックスバリア部５１ｂを構成している。つまり、ロータコア２０は、軸方向に見て、第１マグネット４１ａが延びる方向において第１マグネット４１ａを挟んで配置された一対の第１フラックスバリア部５１ａ，５１ｂを有する。ロータコア２０は、軸方向に見て、第１マグネット４１ｂが延びる方向において第１マグネット４１ｂを挟んで配置された一対の第１フラックスバリア部５１ｃ，５１ｄを有する。 When viewed in the axial direction, both ends of the first magnet 41a in the extending direction are arranged apart from both ends of the first accommodating hole 31a in the extending direction. When viewed in the axial direction, an inner end portion 31d and an outer end portion 31e are arranged adjacent to each other on both sides of the first magnet 41a in the direction in which the first magnet 41a extends. Here, in this embodiment, the inner end portion 31d constitutes the first flux barrier portion 51a. The outer end portion 31e constitutes a first flux barrier portion 51b. That is, the rotor core 20 has a pair of first flux barrier portions 51a and 51b arranged to sandwich the first magnet 41a in the direction in which the first magnet 41a extends when viewed in the axial direction. The rotor core 20 has a pair of first flux barrier portions 51c and 51d arranged to sandwich the first magnet 41b in the direction in which the first magnet 41b extends when viewed in the axial direction.
　このように、ロータコア２０は、軸方向に見て、各第１マグネット４１ａ，４１ｂが延びる方向において各第１マグネット４１ａ，４１ｂのそれぞれを挟んで一対ずつ配置された第１フラックスバリア部５１ａ，５１ｂ，５１ｃ，５１ｄを有する。第１フラックスバリア部５１ａ，５１ｂ，５１ｃ，５１ｄ、後述する第２フラックスバリア部５２ａ，５２ｂ、および後述する溝部８０は、磁束の流れを抑制できる部分である。すなわち、各フラックスバリア部および溝部には、磁束が通りにくい。各フラックスバリア部および溝部は、磁束の流れを抑制できるならば、特に限定されず、空隙部を含んでもよいし、樹脂部等の非磁性部を含んでもよい。 As described above, the rotor core 20 has a pair of first flux barrier portions 51a and 51b arranged with each of the first magnets 41a and 41b interposed therebetween in the direction in which the first magnets 41a and 41b extend when viewed in the axial direction. , 51c and 51d. The first flux barrier portions 51a, 51b, 51c, and 51d, the second flux barrier portions 52a and 52b, which will be described later, and the groove portion 80, which will be described later, are portions that can suppress the flow of magnetic flux. That is, it is difficult for magnetic flux to pass through each flux barrier portion and groove portion. Each flux barrier portion and groove portion is not particularly limited as long as it can suppress the flow of magnetic flux, and may include a void portion or a non-magnetic portion such as a resin portion.
　第２マグネット４２は、第２収容穴３２の内部に収容されている。第２マグネット４２は、一対の第１マグネット４１ａ，４１ｂの径方向内端部よりも径方向外側において一対の第１マグネット４１ａ，４１ｂ同士の間の周方向位置に配置されている。第２マグネット４２は、軸方向に見て第２収容穴３２に沿って延びている。第２マグネット４２は、軸方向に見て径方向と直交する方向に延びている。一対の第１マグネット４１ａ，４１ｂと第２マグネット４２とは、例えば、軸方向に見て、∇形状に沿って配置されている。 The second magnet 42 is housed inside the second housing hole 32 . The second magnet 42 is arranged at a circumferential position between the pair of first magnets 41a and 41b radially outside the radial inner end portions of the pair of first magnets 41a and 41b. The second magnet 42 extends along the second receiving hole 32 when viewed in the axial direction. The second magnet 42 extends in a direction perpendicular to the radial direction when viewed in the axial direction. The pair of first magnets 41a and 41b and the second magnet 42 are arranged, for example, along a ∇ shape when viewed in the axial direction.
　なお、本明細書において「第２マグネットが一対の第１マグネット同士の間の周方向位置に配置されている」とは、第２マグネットの周方向位置が一対の第１マグネット同士の間の周方向位置に含まれていればよく、第１マグネットに対する第２マグネットの径方向位置は特に限定されない。 In this specification, "the second magnet is arranged at a circumferential position between the pair of first magnets" means that the circumferential position of the second magnet is between the pair of first magnets. The radial position of the second magnet with respect to the first magnet is not particularly limited as long as it is included in the directional position.
　第２マグネット４２の軸方向に見た形状は、例えば、磁極中心線ＩＬ１に対して線対称な形状である。第２マグネット４２は、例えば、軸方向に見て長方形状である。図示は省略するが、第２マグネット４２は、例えば、直方体状である。図示は省略するが、第２マグネット４２は、例えば、第２収容穴３２内の軸方向の全体に亘って設けられている。第２マグネット４２の径方向内側部分は、例えば、一対の第１マグネット４１ａ，４１ｂの径方向外端部同士の周方向の間に位置する。第２マグネット４２の径方向外側部分は、例えば、一対の第１マグネット４１ａ，４１ｂよりも径方向外側に位置する。 The shape of the second magnet 42 when viewed in the axial direction is, for example, a line-symmetrical shape with respect to the magnetic pole center line IL1. The second magnet 42 has, for example, a rectangular shape when viewed in the axial direction. Although not shown, the second magnet 42 has, for example, a rectangular parallelepiped shape. Although not shown, the second magnet 42 is provided, for example, over the entirety of the second housing hole 32 in the axial direction. The radially inner portion of the second magnet 42 is positioned, for example, between the radially outer ends of the pair of first magnets 41a and 41b in the circumferential direction. The radially outer portion of the second magnet 42 is positioned, for example, radially outer than the pair of first magnets 41a and 41b.
　第２マグネット４２は、第２収容穴３２内に嵌め合わされている。より詳細には、第２マグネット４２は、第２直線部３２ａ内に嵌め合わされている。第２マグネット４２の側面のうち、第２直線部３２ａが延びる方向と直交する径方向における両側面は、例えば、第２直線部３２ａの内側面とそれぞれ接触している。軸方向に見て第２直線部３２ａが延びる方向において、第２マグネット４２の長さは、例えば、第２直線部３２ａの長さと同じである。 The second magnet 42 is fitted inside the second housing hole 32 . More specifically, the second magnet 42 is fitted inside the second straight portion 32a. Of the side surfaces of the second magnet 42, both side surfaces in the radial direction perpendicular to the direction in which the second straight portion 32a extends are in contact with, for example, the inner side surface of the second straight portion 32a. The length of the second magnet 42 is, for example, the same as the length of the second straight portion 32a in the direction in which the second straight portion 32a extends when viewed in the axial direction.
　軸方向に見て、第２マグネット４２の延伸方向の両端部は、第２収容穴３２の延伸方向の両端部からそれぞれ離れて配置されている。軸方向に見て、第２マグネット４２が延びる方向において第２マグネット４２の両側には、一端部３２ｂと他端部３２ｃとがそれぞれ隣接して配置されている。ここで、本実施形態において一端部３２ｂは、第２フラックスバリア部５２ａを構成している。他端部３２ｃは、第２フラックスバリア部５２ｂを構成している。つまり、ロータコア２０は、軸方向に見て、第２マグネット４２が延びる方向において第２マグネット４２挟んで配置された一対の第２フラックスバリア部５２ａ，５２ｂを有する。一対の第２フラックスバリア部５２ａ，５２ｂおよび第２マグネット４２は、第１マグネット４１ａを挟む一対の第１フラックスバリア部５１ａ，５１ｂのうち径方向外側に位置する第１フラックスバリア部５１ｂと、第１マグネット４１ｂを挟む一対の第１フラックスバリア部５１ｃ，５１ｄのうち径方向外側に位置する第１フラックスバリア部５１ｄとの周方向の間に位置する。 When viewed in the axial direction, both ends of the second magnet 42 in the extending direction are arranged apart from both ends of the second receiving hole 32 in the extending direction. When viewed in the axial direction, one end portion 32b and the other end portion 32c are arranged adjacent to each other on both sides of the second magnet 42 in the direction in which the second magnet 42 extends. Here, in this embodiment, the one end portion 32b constitutes the second flux barrier portion 52a. The other end portion 32c constitutes a second flux barrier portion 52b. In other words, the rotor core 20 has a pair of second flux barrier portions 52a and 52b arranged to sandwich the second magnet 42 in the direction in which the second magnet 42 extends when viewed in the axial direction. The pair of second flux barrier portions 52a and 52b and the second magnet 42 are composed of the first flux barrier portion 51b positioned radially outward of the pair of first flux barrier portions 51a and 51b sandwiching the first magnet 41a, Among the pair of first flux barrier portions 51c and 51d sandwiching one magnet 41b, it is located between the first flux barrier portion 51d located radially outside and the first flux barrier portion 51d in the circumferential direction.
　第１マグネット４１ａの磁極は、軸方向に見て第１マグネット４１ａが延びる方向と直交する方向に沿って配置されている。第１マグネット４１ｂの磁極は、軸方向に見て第１マグネット４１ｂが延びる方向と直交する方向に沿って配置されている。第２マグネット４２の磁極は、径方向に沿って配置されている。 The magnetic poles of the first magnet 41a are arranged along the direction orthogonal to the direction in which the first magnet 41a extends when viewed in the axial direction. The magnetic poles of the first magnet 41b are arranged along the direction orthogonal to the direction in which the first magnet 41b extends when viewed in the axial direction. The magnetic poles of the second magnet 42 are arranged along the radial direction.
　第１マグネット４１ａの磁極のうち径方向外側に位置する磁極と第１マグネット４１ｂの磁極のうち径方向外側に位置する磁極と第２マグネット４２の磁極のうち径方向外側に位置する磁極とは、互いに同じである。第１マグネット４１ａの磁極のうち径方向内側に位置する磁極と第１マグネット４１ｂの磁極のうち径方向内側に位置する磁極と第２マグネット４２の磁極のうち径方向内側に位置する磁極とは、互いに同じである。 The magnetic pole located radially outward among the magnetic poles of the first magnet 41a, the magnetic pole located radially outward among the magnetic poles of the first magnet 41b, and the magnetic pole located radially outward among the magnetic poles of the second magnet 42, are the same as each other. The magnetic pole located radially inward among the magnetic poles of the first magnet 41a, the magnetic pole located radially inward among the magnetic poles of the first magnet 41b, and the magnetic pole located radially inward among the magnetic poles of the second magnet 42, are the same as each other.
　図３に示すように、磁極部７０Ｎにおいて、第１マグネット４１ａの磁極のうち径方向外側に位置する磁極と第１マグネット４１ｂの磁極のうち径方向外側に位置する磁極と第２マグネット４２の磁極のうち径方向外側に位置する磁極とは、例えば、Ｎ極である。磁極部７０Ｎにおいて、第１マグネット４１ａの磁極のうち径方向内側に位置する磁極と第１マグネット４１ｂの磁極のうち径方向内側に位置する磁極と第２マグネット４２の磁極のうち径方向内側に位置する磁極とは、例えば、Ｓ極である。 As shown in FIG. 3, in the magnetic pole portion 70N, the radially outer magnetic pole of the first magnet 41a and the radially outer magnetic pole of the first magnet 41b and the magnetic pole of the second magnet 42 The magnetic pole positioned radially outward is, for example, the N pole. In the magnetic pole portion 70N, the radially inner magnetic pole of the first magnet 41a, the radially inner magnetic pole of the first magnet 41b, and the radially inner magnetic pole of the second magnet 42. The magnetic pole to be used is, for example, the S pole.
　図示は省略するが、磁極部７０Ｓにおいては、磁極部７０Ｎに対して、各マグネット４０の磁極が反転して配置されている。つまり、磁極部７０Ｓにおいて、第１マグネット４１ａの磁極のうち径方向外側に位置する磁極と第１マグネット４１ｂの磁極のうち径方向外側に位置する磁極と第２マグネット４２の磁極のうち径方向外側に位置する磁極とは、例えば、Ｓ極である。磁極部７０Ｓにおいて、第１マグネット４１ａの磁極のうち径方向内側に位置する磁極と第１マグネット４１ｂの磁極のうち径方向内側に位置する磁極と第２マグネット４２の磁極のうち径方向内側に位置する磁極とは、例えば、Ｎ極である。 Although not shown, in the magnetic pole portion 70S, the magnetic pole of each magnet 40 is reversed with respect to the magnetic pole portion 70N. That is, in the magnetic pole portion 70S, the radially outer magnetic pole of the first magnet 41a, the radially outer magnetic pole of the first magnet 41b, and the radially outer magnetic pole of the second magnet 42 The magnetic pole located at is, for example, the S pole. In the magnetic pole portion 70S, the magnetic pole positioned radially inward among the magnetic poles of the first magnet 41a, the magnetic pole positioned radially inward among the magnetic poles of the first magnet 41b, and the magnetic pole positioned radially inward among the magnetic poles of the second magnet 42 The magnetic pole to be used is, for example, the N pole.
　第２マグネット４２の周方向中心が或る１つのティース６３の周方向中心と同じ周方向位置に配置された或る状態（以下では、単に「或る状態」と称する）において、周方向中心が第２マグネット４２の周方向中心と同じ周方向の位置に配置されたティース６３を、ティース６６Ａと呼ぶ。図２～図３は、当該或る状態の一例を示している。つまり、図２～図３に示す或る状態において、ティース６６Ａが「或る１つのティース」に相当する。図２～図３に示す或る状態において、軸方向に見て、ティース６６Ａの周方向中心には、磁極中心線ＩＬ１が通る。また、本明細書において「或る状態」は、「ティース６６Ａの周方向の中心位置がｄ軸である磁極中心線ＩＬ１と一致している」状態である。 In a certain state where the circumferential center of the second magnet 42 is arranged at the same circumferential position as the circumferential center of one tooth 63 (hereinafter simply referred to as a "certain state"), the circumferential center is Teeth 63 arranged at the same circumferential position as the circumferential center of the second magnet 42 are referred to as teeth 66A. 2 and 3 show an example of such a certain state. That is, in a certain state shown in FIGS. 2 and 3, the tooth 66A corresponds to "one certain tooth". In a certain state shown in FIGS. 2 and 3, the magnetic pole center line IL1 passes through the circumferential center of the teeth 66A when viewed in the axial direction. In this specification, "a certain state" is a state in which "the center position of the teeth 66A in the circumferential direction coincides with the magnetic pole center line IL1, which is the d-axis".
　図２～図３に示す或る状態において、ティース６６Ａの周方向一方側（＋θ側）に隣り合うティース６３をティース６６Ｂと呼ぶ。ティース６６Ａの周方向他方側（－θ側）に隣り合うティース６３をティース６６Ｃと呼ぶ。ティース６６Ｂの周方向一方側に隣り合うティース６３をティース６６Ｄと呼ぶ。ティース６６Ｃの周方向他方側に隣り合うティース６３をティース６６Ｅと呼ぶ。ティース６６Ｄの周方向一方側に隣り合うティース６３をティース６６Ｆと呼ぶ。ティース６６Ｅの周方向他方側に隣り合うティース６３をティース６６Ｇと呼ぶ。 In a certain state shown in FIGS. 2 and 3, the teeth 63 adjacent to the teeth 66A on one side in the circumferential direction (+θ side) are called teeth 66B. A tooth 63 adjacent to the tooth 66A on the other circumferential side (−θ side) is called a tooth 66C. A tooth 63 adjacent to one side of the tooth 66B in the circumferential direction is called a tooth 66D. The teeth 63 adjacent to the teeth 66C on the other side in the circumferential direction are called teeth 66E. A tooth 63 adjacent to one side in the circumferential direction of the tooth 66D is called a tooth 66F. The teeth 63 adjacent to the teeth 66E on the other side in the circumferential direction are called teeth 66G.
　図３に示すように、ロータコア２０は、溝部８０を有する。溝部８０は、一対の溝部８０Ａおよび溝部８０Ｂを有する。溝部８０Ａおよび溝部８０Ｂは、軸方向に見て外周面２０ａから径方向内側にそれぞれ窪んでいる。溝部８０Ａおよび溝部８０Ｂは、それぞれロータコア２０を軸方向に貫通している。軸方向に見て、溝部８０Ａおよび溝部８０Ｂは、ｑ軸ＩＬ２ごとに設けられている。ｑ軸ＩＬ２は、ｄ軸に対して電気的に直角方向に延びる軸である。 As shown in FIG. 3, the rotor core 20 has grooves 80 . The groove portion 80 has a pair of groove portions 80A and 80B. The groove portion 80A and the groove portion 80B are recessed radially inward from the outer peripheral surface 20a when viewed in the axial direction. Groove portion 80A and groove portion 80B each penetrate rotor core 20 in the axial direction. When viewed in the axial direction, the groove portion 80A and the groove portion 80B are provided for each q-axis IL2. The q-axis IL2 is an axis extending in a direction electrically perpendicular to the d-axis.
　図４は、ティース６６Ｆと径方向に対向する溝部８０の周辺を拡大した断面図である。図４に示すように、溝部８０Ａと溝部８０Ｂは、ｑ軸ＩＬ２を挟んだ周方向の両側に間隔をあけて設けられている。言い換えると、溝部８０は、軸方向に見てｑ軸ＩＬ２に位置する間隔をあけて周方向に延びる溝部８０Ａと溝部８０Ｂとを有している。溝部８０Ａは、ｑ軸ＩＬ２の周方向一方側に位置する。溝部８０Ｂは、ｑ軸ＩＬ２の周方向他方側に位置する。溝部８０Ａと溝部８０Ｂとは、例えば、軸方向に見て、ｑ軸ＩＬ２に対して線対称に配置されている。以下、ｑ軸ＩＬ２に対して線対称である点を除いて溝部８０Ａと同様の構成については、溝部８０Ｂについての説明を省略する場合がある。 FIG. 4 is an enlarged sectional view of the periphery of the groove portion 80 radially facing the teeth 66F. As shown in FIG. 4, the groove portion 80A and the groove portion 80B are spaced apart from each other in the circumferential direction with the q-axis IL2 interposed therebetween. In other words, the groove portion 80 has a groove portion 80A and a groove portion 80B extending in the circumferential direction with a gap located on the q-axis IL2 when viewed in the axial direction. Groove portion 80A is positioned on one circumferential side of q-axis IL2. Groove portion 80B is located on the other circumferential side of q-axis IL2. For example, the groove portion 80A and the groove portion 80B are arranged line-symmetrically with respect to the q-axis IL2 when viewed in the axial direction. Hereinafter, the description of the groove portion 80B may be omitted for the configuration similar to that of the groove portion 80A except that the groove portion 80B is line-symmetrical with respect to the q-axis IL2.
　軸方向に見てｑ軸ＩＬ２に位置する溝部８０が設けられることで、高速回転時の径方向電磁加振力を低減でき、径方向電磁加振力で生じる電気角１２次のラジアル振動を抑制できる。溝部８０Ａと溝部８０Ｂとがｑ軸ＩＬ２の位置を含んで周方向に間隔をあけずに連続して設けられる場合は、低速回転時の周方向電磁加振力が増加してしまう。本実施形態によれば、ｑ軸ＩＬ２を挟んだ周方向の両側に間隔をあけて溝部８０Ａと溝部８０Ｂとが設けられることで、図３に示すように、或る状態において、溝部８０Ａと溝部８０Ｂとが設けられていないロータコア２０の外周面２０ａがティース６６Ｆおよびティース６６Ｇと径方向に対向する。このため、ティース６６Ｆおよびティース６６Ｇから径方向内側に流れる磁束の磁路が確保されることで、低速回転時の周方向電磁加振力を低減でき、周方向電磁加振力で生じる電気角１２次のラジアル振動を抑制できる。高速回転とは、一例として、モータ（ロータコア２０）の回転数が５０００（ｒｐｍ）以上である。低速回転とは、一例として、モータ（ロータコア２０）の回転数が５０００（ｒｐｍ）未満である。 By providing the groove portion 80 located on the q-axis IL2 when viewed in the axial direction, the radial electromagnetic excitation force during high-speed rotation can be reduced, and the radial vibration of the twelfth electrical angle generated by the radial electromagnetic excitation force can be suppressed. can. If the groove portion 80A and the groove portion 80B are continuously provided in the circumferential direction including the position of the q-axis IL2 without leaving an interval therebetween, the circumferential electromagnetic excitation force increases during low-speed rotation. According to the present embodiment, the groove 80A and the groove 80B are provided on both sides in the circumferential direction with the q-axis IL2 interposed therebetween. The outer peripheral surface 20a of the rotor core 20 without the teeth 80B radially faces the teeth 66F and 66G. Therefore, by securing the magnetic path of the magnetic flux flowing radially inward from the teeth 66F and 66G, the circumferential electromagnetic excitation force during low-speed rotation can be reduced, and the electrical angle 12 generated by the circumferential electromagnetic excitation force can be reduced. The following radial vibration can be suppressed. High-speed rotation means, for example, that the rotation speed of the motor (rotor core 20) is 5000 (rpm) or more. Low-speed rotation means, for example, that the rotation speed of the motor (rotor core 20) is less than 5000 (rpm).
　図４に示すように、溝部８０Ａおよび溝部８０Ｂの径方向の最大寸法をＬ１とし、一対の溝部８０Ａ、８０Ｂ同士の周方向の間隔の最小寸法をＬ２とすると、０．８≦（Ｌ２／Ｌ１）≦１．２の関係を満足する。（Ｌ２／Ｌ１）で表される値が０．８未満の場合、ティース６６Ｆおよびティース６６Ｇから径方向内側に流れる磁束の磁路が狭くなり、低速回転時の周方向電磁加振力の低減が十分ではなくなる可能性がある。（Ｌ２／Ｌ１）で表される値が１．２を超えた場合、高速回転時の径方向電磁加振力の低減が十分ではなくなる可能性がある。（Ｌ２／Ｌ１）で表される値が０．８以上、１．２以下であることで、低速回転時の周方向電磁加振力および高速回転時の径方向電磁加振力を十分に低減できる。 As shown in FIG. 4, when the maximum radial dimension of the grooves 80A and 80B is L1, and the minimum distance between the pair of grooves 80A and 80B in the circumferential direction is L2, 0.8≦(L2/L1 )≦1.2. When the value represented by (L2/L1) is less than 0.8, the magnetic path of the magnetic flux flowing radially inward from the teeth 66F and 66G narrows, reducing the circumferential electromagnetic excitation force during low-speed rotation. may not be enough. If the value represented by (L2/L1) exceeds 1.2, there is a possibility that the reduction in the radial electromagnetic excitation force during high-speed rotation will not be sufficient. When the value represented by (L2/L1) is 0.8 or more and 1.2 or less, the circumferential electromagnetic excitation force during low-speed rotation and the radial electromagnetic excitation force during high-speed rotation are sufficiently reduced. can.
　回転電機１においては、低速回転時には周方向電磁加振力が騒音源となり、高速回転時には径方向電磁加振力が騒音源となる。本実施形態によれば、溝部８０Ａおよび溝部８０Ｂの径方向の最大寸法Ｌ１と、溝部８０Ａ、８０Ｂ同士の周方向の間隔の最小寸法Ｌ２とが、０．８≦（Ｌ２／Ｌ１）≦１．２の関係を満足することで、低速回転時の周方向電磁加振力および高速回転時の径方向電磁加振力を低減し、低速回転時から高速回転時に亘ってモータの回転数に依らず騒音を低減できる。 In the rotating electric machine 1, the circumferential electromagnetic excitation force becomes a noise source during low-speed rotation, and the radial electromagnetic excitation force becomes a noise source during high-speed rotation. According to the present embodiment, the maximum radial dimension L1 of the grooves 80A and 80B and the minimum dimension L2 of the circumferential interval between the grooves 80A and 80B satisfy 0.8≦(L2/L1)≦1. By satisfying the relationship of 2, the circumferential electromagnetic excitation force at low speed rotation and the radial electromagnetic excitation force at high speed rotation can be reduced, regardless of the motor rotation speed from low speed rotation to high speed rotation. Noise can be reduced.
［回転数と１２次電磁加振力の増減比との関係］
　図５は、モータ（ロータコア２０）の回転数と、１２次径方向電磁加振力の増減比との関係を示す図である。電気角１２次径方向電磁加振力の増減比は、溝部８０が設けられない回転電機における電気角１２次径方向電磁加振力に対して、上述した溝部８０Ａおよび溝部８０Ｂを有する回転電機における電気角１２次径方向電磁加振力の増減比が「溝２つ」として示されている。図５における「溝１つ」は、図８に示すように、周方向中心がｑ軸ＩＬ２上に位置し、径方向の最大寸法Ｌ１が１．０ｍｍ、周方向の溝幅Ｌ３が２．０ｍｍの溝部８０Ｃを有する回転電機における電気角１２次径方向電磁加振力の増減比が示されている。「溝２つ」の溝部８０Ａおよび溝部８０Ｂは、上記０．８≦（Ｌ２／Ｌ１）≦１．２の関係を満足する。 [Relationship between rotation speed and increase/decrease ratio of 12th order electromagnetic excitation force]
FIG. 5 is a diagram showing the relationship between the rotation speed of the motor (rotor core 20) and the increase/decrease ratio of the twelfth radial electromagnetic excitation force. The increase/decrease ratio of the radial electromagnetic excitation force of the twelfth electrical angle in the rotating electrical machine having the above-described grooves 80A and 80B is The increase/decrease ratio of the twelfth electrical angle radial electromagnetic excitation force is shown as "two grooves". As shown in FIG. 8, "one groove" in FIG. 5 has a circumferential center located on the q-axis IL2, a maximum radial dimension L1 of 1.0 mm, and a circumferential groove width L3 of 2.0 mm. shows the increase/decrease ratio of the radial electromagnetic excitation force of the 12th electrical angle in the rotary electric machine having the groove portion 80C. The groove portion 80A and the groove portion 80B of "two grooves" satisfy the relationship of 0.8≦(L2/L1)≦1.2.
　図６は、モータ（ロータコア２０）の回転数と、１２次周方向電磁加振力の増減比との関係を示す図である。電気角１２次周方向電磁加振力の増減比は、溝部８０が設けられない回転電機における電気角１２次周方向電磁加振力に対して、上述した溝部８０Ａおよび溝部８０Ｂを有する回転電機における電気角１２次周方向電磁加振力の増減比が「溝２つ」として示され、上記の溝部８０Ｃが「溝１つ」として設けられた回転電機における電気角１２次周方向電磁加振力の増減比が示されている。「溝２つ」の溝部８０Ａおよび溝部８０Ｂは、上記０．８≦（Ｌ２／Ｌ１）≦１．２の関係を満足する。 FIG. 6 is a diagram showing the relationship between the rotation speed of the motor (rotor core 20) and the increase/decrease ratio of the twelfth circumferential electromagnetic excitation force. The increase/decrease ratio of the circumferential electromagnetic excitation force of twelfth electrical angle in the rotating electrical machine having the above-described grooves 80A and 80B is The increase/decrease ratio of the circumferential electromagnetic excitation force of the twelfth electrical angle is indicated as "two grooves", and the groove portion 80C is provided as "one groove" in a rotating electric machine. is shown. The groove portion 80A and the groove portion 80B of "two grooves" satisfy the relationship of 0.8≦(L2/L1)≦1.2.
　図５に示すように、溝部８０Ａおよび溝部８０Ｂが設けられた「溝２つ」と、溝部８０Ｃが設けられた「溝１つ」の両方で、溝部８０が設けられない回転電機よりも高速回転時の径方向電磁加振力を低減できる。
　図６に示すように、溝部８０Ａおよび溝部８０Ｂが設けられた「溝２つ」では、溝部８０が設けられない回転電機と同等の低速回転時の周方向電磁加振力であった。溝部８０Ｃが設けられた「溝１つ」では、溝部８０が設けられない回転電機よりも低速回転時の周方向電磁加振力が増加した。
　本実施形態によれば、溝部８０Ａおよび溝部８０Ｂが、上記０．８≦（Ｌ２／Ｌ１）≦１．２の関係を満足することで、低速回転時の周方向電磁加振力は溝部８０が設けられない回転電機と同等であり、高速回転時の径方向電磁加振力は溝部８０が設けられない回転電機よりも低減できた。 As shown in FIG. 5, both the "two grooves" provided with the grooves 80A and 80B and the "single groove" provided with the grooves 80C rotate at a higher speed than the rotating electric machine without the grooves 80. It is possible to reduce the radial electromagnetic excitation force.
As shown in FIG. 6 , in the case of “two grooves” in which the grooves 80A and 80B are provided, the circumferential electromagnetic excitation force during low-speed rotation is equivalent to that of the rotary electric machine in which the grooves 80 are not provided. In the "single groove" in which the groove portion 80C was provided, the circumferential electromagnetic excitation force during low-speed rotation increased as compared to the rotating electric machine in which the groove portion 80 was not provided.
According to the present embodiment, the groove 80A and the groove 80B satisfy the relationship 0.8≦(L2/L1)≦1.2, so that the circumferential electromagnetic excitation force during low-speed rotation is reduced by the groove 80. It was equivalent to the rotary electric machine without the grooves 80, and the radial electromagnetic excitation force during high-speed rotation could be reduced more than the rotary electric machine without the grooves 80. FIG.
　溝部８０Ａは、軸方向に見て第１直線部８１、８２と、第２直線部８３と、曲線部８４、８５と、を有する。第１直線部８１、８２は、外周面２０ａから径方向の内側に直線状に延びる。第１直線部８１は、周方向で第１直線部８２よりもｑ軸ＩＬ２から遠い。第１直線部８２は、周方向で第１直線部８１よりもｑ軸ＩＬ２に近い。第２直線部８３は、第１直線部８１、８２よりも径方向内側に位置し周方向に直線状に延びる。曲線部８４は、円弧状であり、第１直線部８１と第２直線部８３とをつなぐ。曲線部８５は、円弧状であり、第１直線部８２と第２直線部８３とをつなぐ。 The groove portion 80A has first linear portions 81 and 82, a second linear portion 83, and curved portions 84 and 85 when viewed in the axial direction. The first linear portions 81 and 82 linearly extend radially inward from the outer peripheral surface 20a. The first straight portion 81 is further from the q-axis IL2 than the first straight portion 82 in the circumferential direction. The first linear portion 82 is closer to the q-axis IL2 than the first linear portion 81 in the circumferential direction. The second straight portion 83 is positioned radially inward of the first straight portions 81 and 82 and extends linearly in the circumferential direction. The curved portion 84 has an arc shape and connects the first straight portion 81 and the second straight portion 83 . The curved portion 85 has an arc shape and connects the first straight portion 82 and the second straight portion 83 .
　本実施形態によれば、円弧状の曲線部８４が第１直線部８１と第２直線部８３とをつなぐことで、第１直線部８１と第２直線部８３との交差部の応力集中を緩和できる。本実施形態によれば、円弧状の曲線部８５が第１直線部８２と第２直線部８３とをつなぐことで、第１直線部８２と第２直線部８３との交差部の応力集中を緩和できる。 According to the present embodiment, the arc-shaped curved portion 84 connects the first straight portion 81 and the second straight portion 83, thereby reducing the stress concentration at the intersection of the first straight portion 81 and the second straight portion 83. can be mitigated. According to the present embodiment, the arc-shaped curved portion 85 connects the first straight portion 82 and the second straight portion 83, thereby reducing the stress concentration at the intersection of the first straight portion 82 and the second straight portion 83. can be mitigated.
　溝部８０Ａのうち、ｑ軸ＩＬ２から最も遠い箇所（第１直線部８１の径方向外側の端部）までの周方向の距離は、径方向外側に位置するフラックスバリア部５１ｄとｑ軸ＩＬ２との周方向の最短距離よりも短い。溝部８０Ｂのうち、ｑ軸ＩＬ２から最も遠い箇所までの周方向の距離は、径方向外側に位置するフラックスバリア部５１ｂとｑ軸ＩＬ２との周方向の最短距離よりも短い。 In the groove portion 80A, the circumferential distance from the farthest point from the q-axis IL2 (the radially outer end portion of the first straight portion 81) is the distance between the radially outer flux barrier portion 51d and the q-axis IL2. Shorter than the shortest circumferential distance. The circumferential distance to the farthest point from the q-axis IL2 in the groove portion 80B is shorter than the circumferential shortest distance between the q-axis IL2 and the flux barrier portion 51b positioned radially outward.
　溝部８０Ａのうち、ｑ軸ＩＬ２から最も遠い箇所までの周方向の距離が、径方向外側に位置するフラックスバリア部５１ｄとｑ軸ＩＬ２との周方向の最短距離よりも短いことで、溝部８０Ａとフラックスバリア部５１ｄとの間の磁路が狭くなってしまい磁束の流れを阻害して平均トルクが低下することを抑制できる。溝部８０Ｂのうち、ｑ軸ＩＬ２から最も遠い箇所までの周方向の距離が、径方向外側に位置するフラックスバリア部５１ｂとｑ軸ＩＬ２との周方向の最短距離よりも短いことで、溝部８０Ｂとフラックスバリア部５１ｂとの間の磁路が狭くなってしまい磁束の流れを阻害して平均トルクが低下することを抑制できる。 In the groove portion 80A, the circumferential distance to the furthest point from the q-axis IL2 is shorter than the circumferential shortest distance between the q-axis IL2 and the flux barrier portion 51d located radially outward. It is possible to prevent the magnetic path between the flux barrier portion 51d from narrowing and the flow of the magnetic flux from being obstructed, thereby reducing the average torque. In the groove portion 80B, the circumferential distance to the furthest point from the q-axis IL2 is shorter than the circumferential shortest distance between the q-axis IL2 and the flux barrier portion 51b located radially outward. It is possible to prevent the magnetic path between the flux barrier portion 51b from being narrowed and the flow of magnetic flux from being obstructed, thereby reducing the average torque.
［溝部の数と、平均トルクおよび電気角１２次電磁加振力の増減比との関係］
　図７は、溝部の数と平均トルクの増減比との関係を示すとともに、溝部の数と電気角１２次電磁加振力の増減比との関係を示す図である。図７においては、溝部８０が設けられない回転電機を「溝なし」と示している。「溝１つ」は、図８に示すように、径方向の最大寸法Ｌ１が１．０ｍｍ、周方向の溝幅Ｌ３が４．０ｍｍの溝部８０Ｃを有する回転電機を示している。「溝２つ」は、上述した溝部８０Ａおよび溝部８０Ｂが径方向の最大寸法Ｌ１が１．０ｍｍ、溝部８０Ａ、８０Ｂ同士の周方向の間隔の最小寸法Ｌ２が１．０ｍｍ、周方向の溝幅Ｌ３が４．０ｍｍで設けられた回転電機を示している。 [Relationship Between Number of Grooves and Increase/Decrease Ratio of Average Torque and 12th Electrical Angular Electromagnetic Excitation Force]
FIG. 7 is a diagram showing the relationship between the number of grooves and the increase/decrease ratio of the average torque, and the relationship between the number of grooves and the increase/decrease ratio of the electromagnetic excitation force of 12th electrical angle. In FIG. 7, the rotary electric machine without the groove portion 80 is indicated as "no groove". As shown in FIG. 8, "one groove" indicates a rotary electric machine having a groove portion 80C with a maximum radial dimension L1 of 1.0 mm and a circumferential groove width L3 of 4.0 mm. "Two grooves" have a maximum radial dimension L1 of 1.0 mm for the grooves 80A and 80B, a minimum distance L2 of the circumferential spacing between the grooves 80A and 80B of 1.0 mm, and a groove width in the circumferential direction of 1.0 mm. A rotating electrical machine with L3 of 4.0 mm is shown.
　図７に示すように、平均トルクについては、「溝なし」、「溝１つ」および「溝２つ」のいずれの回転電機の場合も大きな差はなく同等の値である。電気角１２次径方向電磁加振力の増減比については、「溝１つ」および「溝２つ」のいずれの回転電機の場合も溝部８０が設けられない回転電機よりも低減できた。電気角１２次周方向電磁加振力の増減比については、「溝１つ」の回転電機の場合は「溝なし」の回転電機よりも増加し、「溝２つ」の回転電機の場合は「溝なし」の回転電機よりも低減する。 As shown in FIG. 7, the average torque is the same value with no big difference in any of the "no groove", "one groove", and "two groove" rotary electric machines. The increase/decrease ratio of the radial electromagnetic excitation force of the 12th electrical angle can be reduced more than the rotating electric machine in which the groove portion 80 is not provided in both the "single groove" and the "two grooves" rotating electric machines. Regarding the increase/decrease ratio of the twelfth electrical angle circumferential electromagnetic excitation force, in the case of the rotating electric machine with "one groove", it increases more than in the case of the rotating electric machine with "no grooves", and in the case of the rotating electric machine with "two grooves", It is less than that of a "grooveless" rotary electric machine.
　図９は、「溝なし」の回転電機に対して、図８に示した上記「溝１つ」の溝部８０Ｃを有する回転電機における、溝幅Ｌ３と、平均トルク、電気角１２次径方向電磁加振力および電気角１２次周方向電磁加振力の各増減比との関係を示す図である。図９においては、径方向の最大寸法Ｌ１は１．０ｍｍに固定し、円弧状の曲線部の半径は１．０ｍｍに固定している。 FIG. 9 shows the groove width L3, the average torque, the twelfth electrical angle radial electromagnetic FIG. 10 is a diagram showing the relationship between the excitation force and each increase/decrease ratio of the circumferential electromagnetic excitation force of twelfth electrical angle; In FIG. 9, the maximum radial dimension L1 is fixed at 1.0 mm, and the radius of the arc-shaped curved portion is fixed at 1.0 mm.
　図９に示されるように、「溝１つ」の回転電機の場合、平均トルクの増減比については、溝幅Ｌ３の値に依らず大きな差はなく同等の値である。「溝１つ」の回転電機の場合、電気角１２次径方向電磁加振力の増減比は、溝幅Ｌ３の値が２．０～４．０ｍｍの間では溝幅Ｌ３の値が大きいほど低減する。「溝１つ」の回転電機の場合、電気角１２次周方向電磁加振力の増減比は、溝幅Ｌ３の値が大きいほど増加する。このため、「溝１つ」の回転電機の場合、電気角１２次周方向電磁加振力の増減比を低減することは困難である。 As shown in FIG. 9, in the case of the "single groove" rotary electric machine, the average torque increase/decrease ratio is the same value without a large difference regardless of the value of the groove width L3. In the case of a "single groove" rotary electric machine, the increase/decrease ratio of the radial electromagnetic excitation force of the 12th electrical angle is between 2.0 and 4.0 mm. Reduce. In the case of a rotating electric machine having "one groove", the increase/decrease ratio of the circumferential electromagnetic excitation force of the twelfth electrical angle increases as the value of the groove width L3 increases. For this reason, in the case of a rotating electric machine having "one groove", it is difficult to reduce the increase/decrease ratio of the circumferential electromagnetic excitation force of the twelfth electrical angle.
　図１０は、上記「溝なし」の回転電機に対して、図４に示した上記「溝２つ」の溝部８０Ａおよび溝部８０Ｂを有する回転電機における、溝幅Ｌ３と、平均トルク、電気角１２次径方向電磁加振力および電気角１２次周方向電磁加振力の各増減比との関係を示す図である。図１０においては、溝部８０Ａ、８０Ｂ同士の周方向の間隔の最小寸法Ｌ２を１．０ｍｍに固定し、径方向の最大寸法Ｌ１および円弧状の曲線部の半径は１．０ｍｍに固定している。 FIG. 10 shows the groove width L3, the average torque, and the electrical angle 12 in the rotating electric machine having the groove portion 80A and the groove portion 80B of the "two grooves" shown in FIG. FIG. 5 is a diagram showing the relationship between the increase/decrease ratios of the secondary radial electromagnetic excitation force and the electrical angle twelfth circumferential electromagnetic excitation force. In FIG. 10, the minimum dimension L2 of the circumferential interval between the grooves 80A and 80B is fixed at 1.0 mm, and the maximum radial dimension L1 and the radius of the arc-shaped curved portion are fixed at 1.0 mm. .
　図１０に示されるように、「溝２つ」の回転電機の場合、平均トルクの増減比については、溝幅Ｌ３の値に依らず大きな差はなく同等の値である。「溝２つ」の回転電機の場合、電気角１２次径方向電磁加振力の増減比は、溝幅Ｌ３の値が２．０～４．０ｍｍの間では溝幅Ｌ３の値が大きいほど低減する。「溝２つ」の回転電機の場合、電気角１２次周方向電磁加振力の増減比は、溝幅Ｌ３の値が２．０～２．５ｍｍの間では「溝なし」の回転電機よりも増加し、溝幅Ｌ３の値が２．５ｍｍを超え、４．０ｍｍ以下では「溝なし」の回転電機よりも低減する。このため、「溝２つ」の回転電機の場合、溝幅Ｌ３の値を例えば、３．０ｍｍ以上、４．０ｍｍ以下とすることで電気角１２次周方向電磁加振力の増減比を低減できる。 As shown in FIG. 10, in the case of the "two-groove" rotary electric machine, the average torque increase/decrease ratio is the same value without a large difference regardless of the value of the groove width L3. In the case of a rotating electrical machine with two grooves, the increase/decrease ratio of the radial electromagnetic excitation force of the 12th electrical angle is between 2.0 and 4.0 mm. Reduce. In the case of a rotating electric machine with "two grooves", the increase/decrease ratio of the circumferential electromagnetic excitation force of the 12th order in electrical angle is as follows: When the value of the groove width L3 exceeds 2.5 mm and is 4.0 mm or less, it is lower than that of the "no groove" rotary electric machine. For this reason, in the case of a rotating electrical machine with "two grooves", the value of the groove width L3 is set to, for example, 3.0 mm or more and 4.0 mm or less, thereby reducing the increase/decrease ratio of the twelfth electrical angle circumferential electromagnetic excitation force. can.
　図１１は、上記「溝なし」の回転電機に対して、「溝２つ」の溝部８０Ａおよび溝部８０Ｂを有する回転電機における、溝部８０Ａ、８０Ｂ同士の周方向の間隔Ｌ２と、平均トルク、電気角１２次径方向電磁加振力および電気角１２次周方向電磁加振力の各増減比との関係を示す図である。図１１においては、溝幅Ｌ３を２．０ｍｍに固定し、径方向の最大寸法Ｌ１および円弧状の曲線部の半径は１．０ｍｍに固定している。 FIG. 11 shows the circumferential distance L2 between the grooves 80A and 80B in the rotating electric machine having the grooves 80A and 80B of "two grooves", the average torque, the electric power FIG. 10 is a diagram showing the relationship between the increase/decrease ratios of the angular twelfth order radial electromagnetic excitation force and the electrical angle twelfth order circumferential electromagnetic excitation force; In FIG. 11, the groove width L3 is fixed at 2.0 mm, and the maximum radial dimension L1 and the radius of the arc-shaped curved portion are fixed at 1.0 mm.
　図１１に示されるように、「溝２つ」の回転電機の場合、平均トルクの増減比については、周方向の間隔Ｌ２の値が０．２～１．２ｍｍの間では周方向の間隔Ｌ２の値に依らず大きな差はなく同等の値である。「溝２つ」の回転電機の場合、電気角１２次径方向電磁加振力の増減比は、周方向の間隔Ｌ２の値が０．２～１．２ｍｍの間では「溝なし」の回転電機よりも低減する。「溝２つ」の回転電機の場合、電気角１２次周方向電磁加振力の増減比は、周方向の間隔Ｌ２の値が０．２～１．２ｍｍの間では「溝なし」の回転電機よりも増加するが、周方向の間隔Ｌ２の値が１．０ｍｍで増加比が最も小さくなる。このため、「溝２つ」の回転電機の場合、周方向の間隔Ｌ２の値を例えば、１．０ｍｍとすることで電気角１２次周方向電磁加振力の増減比を抑制できる。 As shown in FIG. 11, in the case of the rotating electric machine with “two grooves”, the increase/decrease ratio of the average torque is such that when the value of the circumferential interval L2 is between 0.2 and 1.2 mm, the circumferential interval L2 There is no big difference regardless of the value of , and the values are equivalent. In the case of a rotating electrical machine with "two grooves", the increase/decrease ratio of the radial electromagnetic excitation force of the 12th electrical angle is the same as that of "no groove" rotation when the value of the circumferential interval L2 is between 0.2 and 1.2 mm. Less than electric. In the case of a rotating electrical machine with "two grooves", the increase/decrease ratio of the twelfth-order circumferential electromagnetic excitation force in the electrical angle is "no groove" rotation when the value of the circumferential interval L2 is between 0.2 and 1.2 mm. Although it increases more than the electric machine, the increase ratio is the smallest when the value of the interval L2 in the circumferential direction is 1.0 mm. Therefore, in the case of a rotating electric machine having "two grooves", the increase/decrease ratio of the circumferential electromagnetic excitation force of the twelfth electrical angle can be suppressed by setting the value of the circumferential interval L2 to 1.0 mm, for example.
　以上、添付図面を参照しながら本発明に係る好適な実施形態について説明したが、本発明は係る例に限定されないことは言うまでもない。上述した例において示した各構成部材の諸形状や組み合わせ等は一例であって、本発明の主旨から逸脱しない範囲において設計要求等に基づき種々変更可能である。 Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such examples. The various shapes, combinations, etc., of the constituent members shown in the above examples are merely examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.
　例えば、上記実施形態では、第１マグネット４１ａ，４１ｂと第２マグネット４２とを有する∇型のマグネット４０を例示したが、この構成に限定されない。例えば、マグネット４０が第２マグネット４２を有さず、Ｖ型に配置された第１マグネット４１ａ，４１ｂに磁極片が隣り合う構成の回転電機１であってもよい。また、例えば、マグネット４０が第２マグネット４２を有さず、第１マグネット４１ａ，４１ｂに磁極片が隣り合う組が径方向に間隔をあけて複数組（例えば、二組）配置された構成の回転電機１であってもよい。 For example, in the above embodiment, the ∇-shaped magnet 40 having the first magnets 41a and 41b and the second magnet 42 was exemplified, but the configuration is not limited to this. For example, the rotating electrical machine 1 may have a configuration in which the magnet 40 does not have the second magnet 42 and the magnetic pole pieces are adjacent to the first magnets 41a and 41b arranged in a V shape. Alternatively, for example, the magnet 40 does not have the second magnet 42, and a plurality of sets (for example, two sets) of adjacent magnetic pole pieces are arranged in the first magnets 41a and 41b with an interval in the radial direction. It may be the rotary electric machine 1 .
　１…回転電機、　１０…ロータ、　２０…ロータコア、　２０ａ…外周面、　３０…収容穴、　４０…マグネット、　４１ａ，４１ｂ…第１マグネット、　４２…第２マグネット、　５１ｂ，５１ｄ…第１フラックスバリア部（フラックスバリア部）、　５２ａ，５２ｂ…第２フラックスバリア部、　６０…ステータ、　６１…ステータコア、　６２…コアバック、　６３，６６Ａ，６６Ｂ，６６Ｃ，６６Ｄ，６６Ｅ…ティース、　６５…コイル、　６７…スロット、　７０、７０Ｎ、７０Ｓ…磁極部、　８０Ａ、８０Ｂ…溝部、　８１、８２…第１直線部、　８３…第２直線部、　８４、８５…曲線部、　ＩＬ１…磁極中心線（ｄ軸）、　ＩＬ２…ｑ軸、　Ｊ…中心軸 1... Rotating electric machine 10... Rotor 20... Rotor core 20a... Outer peripheral surface 30... Accommodating hole 40... Magnets 41a, 41b... First magnets 42... Second magnets 51b, 51d... First flux barrier part (Flux barrier portion) 52a, 52b... Second flux barrier portion 60... Stator 61... Stator core 62... Core back 63, 66A, 66B, 66C, 66D, 66E... Teeth 65... Coil 67... Slot , 70, 70N, 70S... magnetic pole portions, 80A, 80B... groove portions, 81, 82... first straight portion, 83... second straight portion, 84, 85... curved portion, IL1... magnetic pole center line (d-axis), IL2 … q-axis, J … central axis

Claims (4)

  1. 　中心軸を中心として回転可能なロータと、
    　前記ロータの径方向外側に位置するステータと、
    　を備え、
    　前記ロータは、
    　　複数の収容穴を有するロータコアと、
    　　前記複数の収容穴の内部にそれぞれ収容された複数のマグネットと、
    　を有し、
    　前記ステータは、
    　　前記ロータコアを囲む環状のコアバック、および前記コアバックから径方向内側に延び周方向に間隔を空けて並んで配置された複数のティースを有するステータコアと、
    　　前記ステータコアに取り付けられた複数のコイルと、
    　を有し、
    　前記複数のマグネットは、極を構成し、ｑ軸を介して前記周方向に複数配置され、
    　前記ロータコアは、
    　　軸方向に見て外周面における前記ｑ軸を挟んだ周方向の両側に間隔をあけて、径方向内側に窪んだ一対の溝部をそれぞれ有し、
    　　前記溝部の径方向の最大寸法をＬ１とし、一対の前記溝部同士の周方向の間隔の最小寸法をＬ２とすると、　０．８≦（Ｌ２／Ｌ１）≦１．２
    　の関係を満足する、回転電機。     a rotor rotatable about a central axis;
    a stator positioned radially outward of the rotor;
    with
    The rotor is
    a rotor core having a plurality of accommodation holes;
    a plurality of magnets respectively housed inside the plurality of housing holes;
    has
    The stator is
    a stator core having an annular core-back surrounding the rotor core, and a plurality of teeth extending radially inward from the core-back and arranged side by side at intervals in the circumferential direction;
    a plurality of coils attached to the stator core;
    has
    The plurality of magnets constitute poles and are arranged in plurality in the circumferential direction via the q-axis,
    The rotor core is
    having a pair of grooves recessed inward in the radial direction at intervals on both sides in the circumferential direction of the outer peripheral surface across the q-axis when viewed in the axial direction,
    Let L1 be the maximum radial dimension of the grooves, and L2 be the minimum distance between the pair of grooves in the circumferential direction, then 0.8≦(L2/L1)≦1.2
    A rotating electrical machine that satisfies the relationship between
  2. 　前記溝部は、軸方向に見て、前記外周面から径方向の内側に直線状に延びる第１直線部と、
    　前記第１直線部よりも径方向内側に位置し周方向に直線状に延びる第２直線部と、
    　前記第１直線部と前記第２直線部とをつなぐ円弧状の曲線部と、
    　を有する、
    　請求項１に記載の回転電機。     a first linear portion extending linearly inward in the radial direction from the outer peripheral surface when viewed in the axial direction;
    a second straight portion positioned radially inward of the first straight portion and extending linearly in the circumferential direction;
    an arc-shaped curved portion connecting the first straight portion and the second straight portion;
    has a
    The rotary electric machine according to claim 1.
  3. 　前記ロータコアは、
    　　軸方向に見て、前記マグネットが延びる方向において前記マグネットを挟んで一対で配置されたフラックスバリア部を有し、
    　前記溝部のうち、前記ｑ軸から最も遠い箇所までの距離は、
    　一対の前記フラックスバリア部のうち径方向外側に位置する前記フラックスバリア部と前記ｑ軸との最短距離よりも短い、
    　請求項１または２に記載の回転電機。     The rotor core is
    Having a pair of flux barrier portions arranged across the magnet in the direction in which the magnet extends when viewed in the axial direction,
    Among the grooves, the distance to the furthest point from the q-axis is
    shorter than the shortest distance between the flux barrier portion located radially outside of the pair of flux barrier portions and the q-axis;
    The rotary electric machine according to claim 1 or 2.
  4. 　前記複数のマグネットは、
    　　周方向に互いに間隔を空けて配置され、軸方向に見て径方向内側から径方向外側に向かうに従って互いに周方向に離れる方向に延びる一対の第１マグネットと、
    　　前記一対の第１マグネットの径方向内端部よりも径方向外側において前記一対の第１マグネット同士の間の周方向位置に配置され、軸方向に見て径方向と直交する方向に延びる第２マグネットと、
    　を含む、
    　請求項１から３のいずれか一項に記載の回転電機。     The plurality of magnets are
    a pair of first magnets arranged circumferentially spaced apart from each other and extending in directions away from each other in the circumferential direction as viewed in the axial direction from the radially inner side to the radially outer side;
    A second magnet is arranged at a circumferential position between the pair of first magnets radially outside of the radial inner end portions of the pair of first magnets and extends in a direction orthogonal to the radial direction when viewed in the axial direction. a magnet;
    including,
    The rotary electric machine according to any one of claims 1 to 3.
PCT/JP2021/021979 2021-02-15 2021-06-09 Rotating electrical machine WO2022172479A1 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005354798A (en) * 2004-06-10 2005-12-22 Fujitsu General Ltd Electric motor
JP2017050965A (en) * 2015-09-01 2017-03-09 日産自動車株式会社 Rotor structure for rotary electric machine
JP2017085821A (en) * 2015-10-29 2017-05-18 株式会社富士通ゼネラル Rotor and permanent magnet motor
WO2018235145A1 (en) * 2017-06-19 2018-12-27 日産自動車株式会社 Rotating electric machine rotor

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005354798A (en) * 2004-06-10 2005-12-22 Fujitsu General Ltd Electric motor
JP2017050965A (en) * 2015-09-01 2017-03-09 日産自動車株式会社 Rotor structure for rotary electric machine
JP2017085821A (en) * 2015-10-29 2017-05-18 株式会社富士通ゼネラル Rotor and permanent magnet motor
WO2018235145A1 (en) * 2017-06-19 2018-12-27 日産自動車株式会社 Rotating electric machine rotor

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