WO2019054047A1 - Electric motor, electric air blower, electric vacuum cleaner, and air towel - Google Patents

Electric motor, electric air blower, electric vacuum cleaner, and air towel Download PDF

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Publication number
WO2019054047A1
WO2019054047A1 PCT/JP2018/026971 JP2018026971W WO2019054047A1 WO 2019054047 A1 WO2019054047 A1 WO 2019054047A1 JP 2018026971 W JP2018026971 W JP 2018026971W WO 2019054047 A1 WO2019054047 A1 WO 2019054047A1
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WO
WIPO (PCT)
Prior art keywords
rotor
recess
core
motor
electric blower
Prior art date
Application number
PCT/JP2018/026971
Other languages
French (fr)
Japanese (ja)
Inventor
哲夫 嶋崎
Original Assignee
パナソニックＩｐマネジメント株式会社
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Publication date
Application filed by パナソニックＩｐマネジメント株式会社 filed Critical パナソニックＩｐマネジメント株式会社
Publication of WO2019054047A1 publication Critical patent/WO2019054047A1/en

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    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47L—DOMESTIC WASHING OR CLEANING; SUCTION CLEANERS IN GENERAL
    • A47L9/00—Details or accessories of suction cleaners, e.g. mechanical means for controlling the suction or for effecting pulsating action; Storing devices specially adapted to suction cleaners or parts thereof; Carrying-vehicles specially adapted for suction cleaners
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • 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
    • H02K15/00—Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines
    • H02K15/16—Centering rotors within the stator; Balancing rotors
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
    • H02K7/14—Structural association with mechanical loads, e.g. with hand-held machine tools or fans

Definitions

  • the present disclosure relates to an electric motor, an electric blower, a vacuum cleaner, and an air towel.
  • the present disclosure particularly relates to an electric motor used for household electric appliances and the like, an electric blower using the electric motor, and electric appliances such as a vacuum cleaner and an air towel using the electric blower.
  • the electric motor is used, for example, for an electric blower mounted on a vacuum cleaner.
  • a rotary fan of the electric blower a centrifugal fan capable of obtaining a high suction pressure is used.
  • the centrifugal fan is fixed to the shaft (rotary shaft) of the motor and generates wind pressure by rotating at high speed.
  • the vibration of the electric blower is caused by the weight balance deviation in the rotational direction of the rotor of the motor. That is, when the center of gravity of the rotor is decentered from the rotation axis, the rotation of the rotor generates a centrifugal force proportional to the distance between the center of gravity and the rotation axis, the rotation balance of the rotor is lost, and vibration occurs in the electric blower . Since the centrifugal force is proportional to the square of the number of rotations, especially when the rotor rotates at high speed, the centrifugal force also increases and the vibration increases.
  • Patent Document 1 discloses that the center-of-gravity balance is corrected by cutting a part of the outer peripheral portion of the core forming the rotor.
  • the present disclosure is made to solve such a problem, and it is an object of the present disclosure to provide a low noise motor and the like.
  • one aspect of a motor according to the present disclosure includes a rotor, and a shaft fixed to the rotor and extending in the axial direction of the rotor.
  • the rotor has a core in which a plurality of teeth are formed, and a coil disposed between adjacent teeth.
  • the core has a first recess in which a portion of the outer surface of the core is recessed.
  • the first recess has a bottom surface and a pair of side surfaces facing in the rotational direction of the rotor.
  • the axial direction of the rotor refers to the direction in which the axial center of the rotor extends.
  • one aspect of the electric blower according to the present disclosure includes the above-described electric motor, and a rotating fan attached to a shaft included in the electric motor.
  • mode of the vacuum cleaner which concerns on this indication is provided with said electric blower and the control part which controls an electric blower.
  • one aspect of the air towel according to the present disclosure includes the above-described electric blower and a control unit that controls the electric blower.
  • the motor according to the present disclosure it is possible to suppress wind noise while suppressing the vibration caused by the deviation of the weight balance. Therefore, a low noise motor and the like can be realized.
  • FIG. 1 is an external perspective view of the electric blower according to the embodiment.
  • FIG. 2 is a half sectional view of the electric blower according to the embodiment.
  • FIG. 3 is an exploded view of the electric blower according to the embodiment.
  • FIG. 4 is a perspective view showing a structure around a rotor provided in the motor according to the embodiment.
  • FIG. 5 is a principal part expanded sectional view of the rotor with which the electric motor which concerns on embodiment is provided.
  • FIG. 6 is an enlarged view of a region VI surrounded by a broken line in FIG.
  • FIG. 7 is a view for explaining a conventional cutting method when cutting a core of a rotor to form a recess.
  • FIG. 8 is an enlarged view of a region VIII surrounded by a broken line in FIG.
  • FIG. 9 is a view for explaining the cutting method according to the embodiment when cutting the core of the rotor to form a recess.
  • FIG. 10 is a diagram showing the relationship between the frequency and the sound pressure in the conventional electric fan.
  • FIG. 11 is a diagram showing the relationship between the frequency and the sound pressure in the electric fan according to the embodiment.
  • FIG. 12 is a cross-sectional view showing the configuration of the first recess formed in the rotor provided in the motor according to an example of the embodiment.
  • FIG. 13 is a cross-sectional view showing a configuration of a first recess formed in a rotor provided to a motor according to another example of the embodiment.
  • FIG. 14 is a schematic view showing an example of a vacuum cleaner using the electric blower according to the embodiment.
  • FIG. 15 is a schematic view showing an example of an air towel using the electric blower according to the embodiment.
  • FIG. 16 is a cross-sectional view showing a configuration of a first recess formed in a rotor provided in a motor according to a modification.
  • FIG. 17 is a cross-sectional view showing the configuration of the first recess formed in the rotor provided in the motor according to the modification.
  • FIG. 18 is a cross-sectional view showing a configuration of a first recess formed in a rotor provided in a motor according to a modification.
  • FIG. 19 is a cross-sectional view showing the configuration of the first recess formed in the rotor provided in the motor according to the modification.
  • FIG. 16 is a cross-sectional view showing a configuration of a first recess formed in a rotor provided in a motor according to a modification.
  • FIG. 17 is a cross-sectional view showing the configuration of the first recess formed in the rotor provided
  • FIG. 20 is a cross-sectional view showing the configuration of the first recess formed in the rotor provided in the motor according to the modification.
  • FIG. 21 is a cross-sectional view showing a configuration of a first recess formed in a rotor provided in a motor according to a modification.
  • FIG. 22 is a cross-sectional view showing the configuration of the first recess formed in the rotor provided in the motor according to the modification.
  • FIG. 23 is a cross-sectional view showing the configuration of the first recess formed in the rotor provided in the motor according to the modification.
  • FIG. 1 is an external perspective view of the electric blower 1 according to the embodiment.
  • FIG. 2 is a half sectional view of the electric blower 1.
  • FIG. 3 is an exploded view of the electric blower 1. The arrows shown in FIG. 2 indicate the flow of air drawn into the electric blower 1 by the rotation of the rotary fan 3.
  • the electric blower 1 in the present embodiment includes a motor 2 (motor), a rotary fan 3, an air guide 4, a bracket 5, a frame 6 and a fan case 7. Prepare.
  • the motor 2 rotates the rotating fan 3 as a rotating load.
  • the detailed configuration of the motor 2 will be described later.
  • the rotating fan 3 sucks air into an outer housing (housing) constituted by the frame 6 and the fan case 7.
  • the rotation fan 3 is attached to a predetermined portion of a shaft 30 of the motor 2 and rotates by the rotation of the shaft 30.
  • the rotary fan 3 is attached to the tip of the shaft 30 protruding from the bracket 5.
  • the rotary fan 3 is a centrifugal fan that can obtain high suction pressure. The rotation of the rotary fan 3 generates a wind pressure, and air is sucked from the air inlet 7 a of the fan case 7.
  • the air guide 4 forms an air passage around the outer periphery of the rotary fan 3.
  • the air guide 4 is formed in a ring shape so as to surround the rotary fan 3.
  • the air guide 4 has a plurality of diffuser blades 4a as a guide plate for rectifying the flow of gas.
  • the air guide 4 rectifies the flow of air drawn from the air inlet 7 a of the fan case 7 by the rotation of the rotary fan 3 to generate a swirling flow, and smoothly flows the drawn gas into the frame 6.
  • the bracket 5 covers the opening of the frame 6 together with the air guide 4.
  • the bracket 5 is disposed to cover the first bearing portion 60.
  • An opening is formed in the bracket 5, and the air rectified by the air guide 4 passes through the opening of the bracket 5 and flows into the frame 6.
  • the frame 6 is a first housing for housing the motor 2. At the bottom of the frame 6, a plurality of exhaust ports 6 a for discharging the air sucked by the rotation of the rotary fan 3 are formed.
  • the fan case 7 is a second housing that houses the rotary fan 3.
  • the fan case 7 is fixed to the frame 6 so as to cover the rotary fan 3, the air guide 4 and the bracket 5.
  • the fan case 7 has an air inlet 7a for suctioning the outside air.
  • the motor 2 in the present embodiment is a brushed commutator motor, and includes a rotor 10, a stator 20, a shaft 30, a commutator 40, a brush 50, and a first motor.
  • a bearing portion 60 and a second bearing portion 70 are provided.
  • the rotor 10 (rotor) rotates around the shaft 30 by the magnetic force of the stator 20.
  • the rotor 10 is an inner rotor.
  • the rotor 10 is disposed inside the stator 20, as shown in FIG. Specifically, the rotor 10 is surrounded by the stator 20 via a minute air gap with the stator 20.
  • the rotor 10 rotates at a high speed, for example, at 40,000 rpm (revolutions per minute).
  • the stator 20 (stator) generates a magnetic force acting on the rotor 10.
  • the stator 20 is disposed to surround the rotor 10.
  • the stator 20 is constituted by, for example, a permanent magnet having an S pole and an N pole, but may be constituted by a core (stator core) and a winding coil (stator coil).
  • the stator 20 is fixed to, for example, the frame 6.
  • the shaft 30 is a rotation axis serving as a center when the rotor 10 rotates.
  • the shaft 30 extends in the longitudinal direction which is the axial center C direction.
  • the shaft 30 is formed of, for example, a metal rod.
  • the shaft 30 is fixed to the rotor 10. Specifically, the shaft 30 is fixed to the core 11 in a state of penetrating the center of the core 11 of the rotor 10 so as to extend on both sides of the rotor 10, for example. As an example, the shaft 30 is press-fit into the core 11 of the rotor 10.
  • the shaft 30 passes through the rotor 10 and is disposed to extend on both sides of the rotor 10.
  • One end (the end on the rotary fan 3 side) of the shaft 30 is supported by the first bearing portion 60.
  • the other end of the shaft 30 is supported by the second bearing portion 70.
  • the first bearing portion 60 and the second bearing portion 70 are bearings that support the shaft 30.
  • the shaft 30 is held by the first bearing portion 60 and the second bearing portion 70 so as to be rotatable.
  • One end of the shaft 30 protrudes from the first bearing portion 60 and penetrates the bracket 5.
  • the rotating fan 3 is attached to the tip of the shaft 30 protruding from the bracket 5.
  • the commutator 40 is attached to the shaft 30.
  • the commutator 40 is fixed to a portion of the shaft 30 between the rotor 10 and the second bearing portion 70.
  • the commutator 40 is electrically connected to the coil 12 of the rotor 10 and is in sliding contact with the brush 50.
  • the commutator 40 is constituted by a plurality of segments insulated and separated from each other in the rotational direction of the shaft 30.
  • the brush 50 is a power supply brush for supplying power to the rotor 10 by contacting the commutator 40.
  • the brush 50 contacts the commutator 40 to supply armature current to the commutator 40.
  • the brush 50 is a carbon brush.
  • the brush 50 is a long substantially rectangular parallelepiped.
  • the brush 50 is disposed slidably on the commutator 40.
  • the brushes 50 are provided as a pair, and the pair of brushes 50 are disposed to face each other across the commutator 40 so as to sandwich the commutator 40.
  • the inner front end portions of the pair of brushes 50 are in contact with the commutator 40.
  • an end surface on the inner side (shaft 30 side) of the brush 50 in the longitudinal direction is a contact surface with the commutator 40.
  • the rotary fan 3 rotates.
  • the rotation of the rotary fan 3 causes air to be drawn into the inside of the fan case 7 from the air inlet 7 a of the fan case 7, thereby generating an air flow from the central portion of the rotary fan 3 toward the outer diameter side.
  • the air drawn into the inside of the fan case 7 is guided to the outer peripheral portion of the fan case 7 by the diffuser 4a of the air guide 4 and becomes a swirling flow at the gap between the air guide 4 and the fan case 7.
  • Flows into the frame 6 through the opening of The inflowing swirling flow is discharged from the exhaust port 6 a of the frame 6 to the outside of the electric blower 1 while cooling the rotor 10 and the stator 20 of the motor 2.
  • the air flowing into the frame 6 passes through the gap in the frame 6 (the gap between the stator 20 and the frame 6, the gap between the rotor 10 and the stator 20, etc.), and the exhaust port of the frame 6 It is discharged from 6a.
  • FIG. 4 is a perspective view showing the structure around the rotor 10 provided in the motor 2 according to the embodiment.
  • FIG. 5 is a principal part expanded sectional view of the rotor 10 with which the motor 2 is provided.
  • the arrow W indicates the flow of air passing around the rotor 10
  • the arrow R indicates the rotation direction of the shaft 30.
  • the rotor 10 has the core 11 (rotor core) in which several teeth 11a were formed, and the coil 12 (rotor coil) arrange
  • teeth teeth: plural form
  • tooth tooth
  • the core 11 is formed of a laminate in which a plurality of electromagnetic steel plates are stacked in the axial direction of the shaft 30.
  • the electromagnetic steel plates constituting the core 11 are, for example, punched electromagnetic steel plates, and have the same shape and the same thickness.
  • the plurality of magnetic steel sheets are fixed to one another, for example, by caulking.
  • the core 11 may be a bulk body of a magnetic material instead of a laminate of a plurality of electromagnetic steel sheets.
  • each tooth 11a formed in the core 11 is provided along the rotation direction of the rotor 10 at predetermined intervals over the entire circumference of the core 11.
  • each tooth 11a has a substantially T-shaped cross section.
  • a space between two adjacent teeth 11a constitutes a slot 11b (iron core groove).
  • the coil 12 is disposed in the slot 11b.
  • the coil 12 is a winding coil (field winding) wound around the core 11.
  • the winding method of the coil 12 may be lap winding or concentrated winding.
  • the coils 12 are electrically connected to each other via the commutator 40 and the brush 50.
  • the wedge 13 is arrange
  • the core 11 has a first recess 111 and a second recess 112 in which a part of the outer surface of the core 11 is recessed.
  • the first recess 111 and the second recess 112 are cutting portions formed by partially cutting the outer surface of the core 11 in order to correct the center of gravity balance of the rotor 10.
  • the first recess 111 and the second recess 112 are formed by cutting each tooth 11 a so as to lower a part of the outer surface of the plurality of teeth 11 a of the core 11.
  • the first recess 111 has a bottom surface 111 a and a pair of side surfaces 111 b facing in the rotational direction of the rotor 10. At both end portions of the first recess 111 in the rotational direction of the rotor 10, steps formed of the side surface 111b and the outer surface of the core 11 are formed. That is, by forming the first recess 111, two steps are formed in the core 11.
  • the first recess 111 is formed by cutting the core 11 extensively to adjust the weight of the rotor 10 dynamically. For this reason, the first recess 111 is formed across the plurality of continuous teeth 11 a and provided at the end of the core 11 in the longitudinal direction of the shaft 30.
  • the first concave portion 111 is formed at an end of the core 11 opposite to the side of the commutator 40 (an end of the rotary fan 3).
  • the 1st recessed part 111 is formed over the continuous 5 teeth 11a.
  • the bottom surface 111a of the first recess 111 is present in all five consecutive teeth 11a.
  • the side surface 111b of the 1st recessed part 111 exists in each of the teeth 11a of the both ends of five continuous teeth 11a. That is, with respect to three teeth 11a except two of the two end portions of the five consecutive teeth 11a, only the bottom surface 111a exists among the bottom surface 111a and the side surface 111b.
  • the tooth 11a in which only the bottom surface 111a is present is not limited to three as illustrated.
  • the bottom surfaces 111a of the three teeth 11a are present in the entire region along the rotation direction of the rotor 10 of each tooth 11a.
  • FIG. 6 is an enlarged view of a region VI surrounded by a broken line in FIG.
  • the outer circumferential line 15 includes the outer surface of the core 11.
  • the inner circumferential line 16 includes the bottom surface 111 a of the first recess 111.
  • One end of the side surface 111 b intersects the outer circumferential line 15, and the other end intersects the inner circumferential line 16.
  • the first intersection point 15a is an intersection point of the outer peripheral line 15 and the side surface 111b.
  • the second intersection 16a is an intersection of the inner circumferential line 16 and the side surface 111b.
  • a straight line passing the first intersection point 15a and the second intersection point 16a is taken as Rb.
  • An angle ⁇ 1 formed by the straight line Rb and the bottom surface 111a is an obtuse angle.
  • the second intersection 16a is the first intersection 15a and the axis It is located closer to the bottom surface 111 a than a straight line Ra passing through the heart C.
  • the angle of the step of the cutting boundary with the outer surface of the core 11 in the first recess 111 is not 90 °.
  • the cross section having the axis C of the shaft 30 as a normal is also referred to as a cross section intersecting the axis C.
  • each of the pair of side surfaces 111 b includes, in a cross-section normal to the axial center C of the shaft 30, a portion whose depth changes along the rotation direction of the rotor 10.
  • each of the pair of side surfaces 111 b is a tapered surface
  • each side surface 111 b is a portion whose depth changes along the rotation direction of the rotor 10 as a whole surface. That is, each side surface 111 b is an inclined surface whose depth gradually decreases along the rotation direction of the rotor 10.
  • the taper angle ⁇ 2 (inclination angle) of each side surface 111b is 45 ° which is an acute angle. That is, an angle ⁇ 1 between each side surface 111b and the bottom surface 111a is 135 ° which is an obtuse angle.
  • the first recess 111 has a line-symmetrical shape in a cross section with the axis C of the shaft 30 as a normal. Therefore, the pair of side surfaces 111 b are forward tapered surfaces, and both have the same taper angle.
  • the second recess 112 is formed by cutting the core 11 into a small area in order to finely adjust the weight of the rotor 10. Specifically, the second recess 112 is formed to finely adjust the position of the center of gravity of the rotor 10 after the first recess 111 is formed. For this reason, the cutting amount of the second recess 112 is smaller than the cutting amount of the first recess 111.
  • the second recess 112 is a V-shaped groove. That is, the cross-sectional shape of the second recess 112 is V-shaped in a cross section with the axis C of the shaft 30 as a normal. Alternatively, the cross-sectional shape of the second recess 112 is U-shaped in a cross section with the axis C of the shaft 30 as a normal.
  • the second recess 112 is provided at the central portion of the core 11 in the longitudinal direction of the shaft 30.
  • the 2nd crevice 112 is formed in tooth 11a different from teeth 11a in which the 1st crevice 111 was formed, it may be formed in teeth 11a in which the 1st crevice 111 was formed.
  • FIG. 7 is a view for explaining a conventional cutting method when cutting a core of a rotor to form a recess.
  • the balance of the center of gravity of the rotor 10 is corrected by cutting a part of the outer peripheral portion of the core 11 of the rotor 10 using the hourglass-shaped cutting blade 200X. .
  • a recess 111X is formed as a cutting portion.
  • the recess 111X is formed across the plurality of teeth 11a.
  • the recess 111 ⁇ / b> X has a bottom surface 111 x which is a flat surface, and a pair of side surfaces 111 y facing in the rotational direction of the rotor 10. That is, on both ends of the recess 111X in the rotational direction of the rotor 10, steps are formed as cutting boundaries.
  • the recess 111 ⁇ / b> X has two steps in the rotational direction of the rotor 10.
  • FIG. 8 is an enlarged view of a region VIII surrounded by a broken line in FIG.
  • the angle between the side surface 111y and the outer surface of the core 11 is 90 °, and the entire side surface 111y is perpendicular to the bottom surface 111x. That is, the step of the cutting boundary with the outer surface of the core 11 in the recess 111X is 90 °.
  • the noise in the electric blower is one factor that is the vibration of the rotor due to the deviation of the weight balance of the rotor.
  • the vibration of the rotor can suppress the noise due to the vibration of the rotor by cutting a part of the core of the rotor and correcting the center-of-gravity balance of the rotor as described above.
  • NZ sound has the largest sound pressure among the noises of the electric blower.
  • it is possible to suppress NZ noise by devising the air passage shape of the air guide.
  • the factor behind the NZ sound is a sound with a frequency that is an even multiple (twice, four times,%) Of the rotational speed of the rotary fan.
  • the generation factor of the sound having a frequency that is an even multiple of the rotational speed of the rotary fan is the harmonic component of the vibration of the motor or the sliding noise between the brush and the commutator.
  • a sound having a frequency that is an even multiple of the rotational speed of the rotating fan is formed by cutting the rotor core when correcting the center of gravity balance of the rotor.
  • the inventor has found that the correlativity with the recessed portion (cutting portion) is high. Specifically, it has been found that the sound having a frequency that is an even multiple of the rotational speed is a wind noise generated by the step of the recess formed in the core of the rotor by cutting the core. The wind noise will be described below.
  • the cutting of the core when correcting the center of gravity balance of the rotor is performed using a drum-shaped cutting blade as described above.
  • the steps of the cutting boundary in the recess are formed at two places in the rotational direction of the rotor.
  • the second cutting may be performed.
  • two cuts may be performed even when the initial imbalance amount is large.
  • the core cutting amount may be increased, but in order to ensure the core magnetic circuit and mechanical strength, it is necessary to regulate the cutting depth of the recess. There is. For this reason, instead of increasing the cutting amount of the core at one time, the cutting position may be dispersed and the core may be cut in two steps. Thus, when the core is cut twice, there are four steps in total at the cutting boundaries in the two concave portions (cutting portions).
  • each step of the recess 111X formed by cutting the core 11 is 90 °, which is sharp. For this reason, it was found that a wind noise was generated when the rotary fan was rotated due to the recess 111X formed by cutting the core 11.
  • the wind noise due to the recess 111X formed by the cutting of the core 11 is the generation factor of the sound having a frequency that is an even multiple of the rotational speed of the rotating fan.
  • the frequency of the even multiple of the rotational speed is a frequency in the audible range of about 1,000 Hz to 3,000 Hz. That is, the frequency that is an even multiple of the rotational speed of the rotating fan is a frequency band where the sensitivity of human hearing is high. Therefore, it is easy to become an unpleasant sound.
  • the present disclosure is made based on such findings.
  • the inventor of the present invention has obtained an idea that the wind noise caused by the recess can be suppressed by eliminating the corner of the step of the cutting boundary in the recess in the recess formed by cutting the core of the rotor. .
  • the first recess 111 includes a bottom surface 111 a and a pair of side surfaces 111 b facing in the rotational direction R of the rotor 10.
  • the pair of side surfaces 111b is a first intersection point 15a where the outer surface of the core 11 intersects one side surface 111b, the bottom surface 111a and one side surface 111b And a second intersection point 16a intersecting with each other.
  • a straight line passing the first intersection point 15a and the second intersection point 16a is taken as Rb.
  • An angle ⁇ 1 formed by the straight line Rb and the bottom surface 111a is an obtuse angle.
  • the second intersection 16a is located closer to the bottom surface 111a than a straight line Ra passing through the first intersection 15a and the axis C.
  • the first recess 111 is provided across the plurality of teeth 11 a of the core 11, and the side surface 111 b of the first recess 111 is a tapered surface.
  • This configuration can further reduce sudden collision of air in the first recess 111. Therefore, the sound of the frequency of the even multiple of the rotation speed of the rotary fan can be further suppressed.
  • FIG. 9 is a view for explaining the cutting method according to the embodiment when the core 11 of the rotor 10 is cut to form a recess.
  • the first recess 111 can be formed using a drum-shaped cutting blade 200, as shown in FIG.
  • the cutting blade 200 in the present embodiment has a shape in which flat portions 201 are formed at both ends of the conventional cutting blade 200X shown in FIG. That is, both ends of the cutting blade 200 are in a substantially parallel cylindrical shape.
  • the first recess 111 By forming the first recess 111 by cutting the core 11 (the teeth 11a) using the drum-shaped cutting blade 200 configured in this manner, the cutting depth gradually increases in the vicinity of the cutting boundary after cutting. It gets shallow. For this reason, a sharp level difference does not occur at the cutting boundary.
  • the side surface 111b of the first recess 111 can be made into a tapered surface (inclined surface) having a taper angle ⁇ 2 of 45 °, for example. That is, the angle ⁇ 1 formed by the straight line Rb and the bottom surface 111a is 135 °.
  • FIG. 10 is a diagram showing the relationship between the frequency and the sound pressure in the conventional electric fan.
  • FIG. 11 is a diagram showing the relationship between the vibration frequency and the sound pressure in the electric blower 1 according to the embodiment.
  • the conventional electric blower in FIG. 10 uses a motor having a rotor 10 in which the core 11 is cut by the conventional cutting blade 200X shown in FIG. 7 to form a recess 111X.
  • the electric blower 1 according to the present embodiment in FIG. 11 uses the motor 2 having the rotor 10 in which the first recess 111 is formed by cutting the core 11 with the cutting blade 200 shown in FIG.
  • the sound pressure of the conventional electric blower is 76.8 dB (FIG. 10) at 1306 Hz, which is a frequency twice (2 N) of the rotational speed.
  • the sound pressure of the electric blower 1 according to the embodiment is 70.5 dB (FIG. 11).
  • the sound pressure of the conventional electric blower is 79.5 dB (FIG. 10), whereas the electric power according to the present embodiment.
  • the sound pressure of the blower 1 is 80.0 dB (FIG. 11).
  • the sound pressure of the conventional electric blower and the electric blower 1 according to the present embodiment are about the same in sound pressure as to the frequency seven times the rotational speed, and the first recess 111 in the electric blower 1 according to the present embodiment.
  • the sound pressure suppression effect appears even at 653 Hz, which is a frequency that is one time the rotational speed (1N). Specifically, the sound pressure at a frequency that is one time the rotational speed is due to the vibration noise of the motor.
  • the sound pressure of the conventional electric blower is 76.8 dB and the sound pressure of the electric blower 1 according to the present embodiment is 73.5 dB at a frequency that is one time the rotational speed.
  • a straight line Rb passing through the first intersection point 15a and the second intersection point 16a and an angle ⁇ 1 formed by the bottom surface 111a are obtuse angles
  • the efficiency of the conventional motor was 52.2%, and the efficiency of the motor 2 in the present embodiment was 52.5%. That is, in a cross section having the axis C of the shaft 30 as a normal, the first recess 111 is formed such that the angle ⁇ 1 between the straight line Rb passing the first intersection 15a and the second intersection 16a and the bottom surface 111a is an obtuse angle It was also found that by doing this, the efficiency of the motor was improved.
  • FIG. 12 is a cross-sectional view showing the configuration of the first recess 111 formed in the rotor 10 of the motor 2 according to an example of the embodiment.
  • FIG. 13 is a cross-sectional view showing the configuration of the first recess 111 formed in the rotor 10 of the motor 2 according to another example of the embodiment. For example, as shown in FIG.
  • the angle ⁇ 1 between the straight line Rb and the bottom surface 111a may be less than 135 ° as long as it is an obtuse angle.
  • an angle ⁇ 1 formed by the straight line Rb and the bottom surface 111a may exceed 135 °.
  • the taper angle ⁇ 2 of the side surface 111b of the first recess 111 is 45 °, which is an acute angle, but the present invention is not limited to this.
  • the taper angle ⁇ 2 of the side surface 111b of the first recess 111 may exceed 45 °
  • the taper angle ⁇ 2 of the side surface 111b of the first recess 111 is It may be less than 45 °.
  • the motor 2 of the present embodiment includes the rotor 10 and the shaft 30 fixed to the rotor 10 and extended in the axial center C direction of the rotor 10.
  • the rotor 10 has a core 11 in which a plurality of teeth 11 a are formed, and a coil 12 disposed between adjacent teeth 11 a.
  • the core 11 has a first recess 111 in which a part of the outer surface of the core 11 is recessed.
  • the first recess 111 has a bottom surface 111 a and a pair of side surfaces 111 b facing in the rotational direction of the rotor 10.
  • At least one of the pair of side surfaces 111b has a first intersection point 15a intersecting with the outer surface of the core 11 and a second intersection point 16a intersecting with the bottom surface 111a.
  • the angle between a straight line Rb passing through the intersection point 15a and the second intersection point 16a and the bottom surface 111a is an obtuse angle.
  • the wind noise can be suppressed while suppressing the vibration caused by the deviation of the weight balance. Therefore, the low noise motor 2 can be realized.
  • the 1st recessed part 111 may be provided over several teeth 11a.
  • the first recess 111 may be provided at the end of the core 11 in the longitudinal direction of the shaft 30.
  • At least one of the pair of side surfaces 111 b may include a portion whose depth changes along the rotation direction of the rotor 10.
  • the portion may be a tapered surface.
  • the portion may be a curved surface.
  • the portion may be at least one of the pair of side surfaces 111b.
  • the 1st recessed part 111 may be line symmetrical.
  • the core 11 may also have a second recess 112 in which a part of the outer surface of the core 11 is recessed.
  • the cross-sectional shape of the 2nd recessed part 112 may be V shape.
  • the cross-sectional shape of the 2nd recessed part 112 may be U-shape.
  • the electric blower 1 of the present embodiment includes the electric motor 2 and the rotary fan 3 attached to the shaft 30 provided in the electric motor 2.
  • FIG. 14 is a schematic view showing an example of a vacuum cleaner 8 using the electric blower 1 according to the embodiment.
  • the vacuum cleaner 8 is provided with the electric blower 1 using the electric motor 2, and the control part 8a which controls the electric blower 1 (electric motor 2).
  • the vacuum cleaner 8 is sucked by the electric blower 1 to clean it.
  • the controller 8a controls the electric blower 1 (electric motor 2). For example, the control unit 8a stops suctioning by the electric blower 1, starts it, or adjusts the suction amount.
  • the electric vacuum cleaner 8 in the present embodiment uses the electric blower 1, a low noise electric vacuum cleaner can be realized.
  • the electric blower 1 may be used as an air towel 9 for drying hands.
  • FIG. 15 is a schematic view showing an example of the air towel 9 using the electric blower 1 according to the embodiment.
  • the air towel 9 includes an electric blower 1 using the electric motor 2 and a control unit 9a that controls the electric blower 1 (electric motor 2).
  • the air towel 9 hot air or cold air is blown by the electric blower 1.
  • the controller 9a controls the electric blower 1 (electric motor 2).
  • the control unit 9a stops or starts air blowing by the electric blower 1, or adjusts the air blowing amount.
  • the air towel 9 in the present embodiment uses the electric blower 1, a low noise air towel can be realized.
  • the above embodiment has been described using an inclined surface which is entirely flat.
  • the side surface of the first recess is not limited to the inclined surface which is entirely flat.
  • the entire first side 111b may be a first concave portion 111A that is a concave curved surface, or as shown in FIG. 17, the entire side 111b is a convex curved surface. It may be a certain first recess 111B.
  • FIG. 16 is a cross-sectional view showing the configuration of the first recess 111A formed in the rotor 10 of the motor 2 according to the modification.
  • FIG. 17 is a cross-sectional view showing the configuration of the first recess 111B formed in the rotor 10 of the motor 2 according to the modification.
  • the side surface 111 b may include both a concave curved surface and a convex curved surface.
  • FIG. 18 is a cross-sectional view showing the configuration of a first recess 111C formed in the rotor 10 of the motor 2 according to the modification.
  • FIG. 19 is a cross-sectional view showing the configuration of the first recess 111D formed in the rotor 10 of the motor 2 according to the modification.
  • the side surface 111b of the first recess 111C shown in FIG. 18 is a convex curved surface on the outer surface side of the core 11, and a concave curved surface on the bottom surface 111a side.
  • the outer surface side of the core 11 is a concave curved surface
  • the bottom surface 111a side is a convex curved surface.
  • the side surface 111b may further include a flat surface.
  • FIG. 20 is a cross-sectional view showing the configuration of a first recess 111E formed in the rotor 10 of the motor 2 according to the modification.
  • FIG. 21 is a cross-sectional view showing the configuration of the first recess 111F formed in the rotor 10 of the motor 2 according to the modification. That is, the ridgeline of the boundary between the side surface 111 b and the outer surface of the core 11 may be chamfered.
  • the corner of the step of the cutting boundary is chamfered so as to be the C surface 111c
  • the side surface 111b of the first recess 111E includes the C surface 111c.
  • the corner of the step of the cutting boundary is chamfered so as to be the R surface 111d
  • the side surface 111b of the first recess 111F includes the R surface 111d.
  • the plane shown in FIG. 20 and FIG. 21 is a cross section having an axis C of the shaft 30 as a normal.
  • the C surface 111 c is a surface located between the outer surface of the core 11 and the side surface 111 b in a cross section with the axial center C of the shaft 30 as a normal.
  • the C surface 111c can be formed by, for example, scraping a corner located between the outer surface of the core 11 and the side surface 111b after forming the first recess 111E.
  • the C surface 111 c can be formed by adjusting the shape of the cutting blade 200 described above. That is, the boundary between each of the pair of side surfaces 111 b and the outer surface of the core 11 may have no corner.
  • the R surface 111 d is a curved surface located between the outer surface of the core 11 and the side surface 111 b in a cross section having the axial center C of the shaft 30 as a normal.
  • the R surface 111d can be formed by, for example, scraping a corner portion located between the outer surface of the core 11 and the side surface 111b.
  • the C surface 111 c can be formed by adjusting the shape of the cutting blade 200 described above.
  • FIG. 22 is a cross-sectional view showing the configuration of the first recess 111G formed in the rotor 10 of the motor 2 according to the modification.
  • FIG. 23 is a cross-sectional view showing the configuration of the first recess 111H formed in the rotor 10 of the motor 2 according to the modification. Specifically, in the first recess 111G shown in FIG.
  • the corner of the step of the cutting boundary is chamfered so as to be the C surface 111c, and the root portion of the step is an inclined surface
  • the side surface 111b of the recess 111G includes a C surface 111c and an inclined surface.
  • the corner of the step of the cutting boundary is chamfered to be the R surface 111d, and the root portion of the step is a curved surface, and the side surface 111b of the first recess 111H Includes the R surface 111 d and the curved surface.
  • each of the two boundaries between each of the pair of side surfaces 111b and the outer surface of the core 11 has no corner, but the present invention is not limited to this. That is, in the first concave portion 111, the first intersection point 15a, which is the intersection point of at least one of the pair of side surfaces 111b and the outer surface of the core 11, and the second intersection point 16a, which is the intersection point of the side surface 111b and the bottom surface 111a It is good if That is, a straight line passing the first intersection point 15a and the second intersection point 16a is taken as Rb. At this time, the angle ⁇ 1 formed by the straight line Rb and the bottom surface 111a may be an obtuse angle.
  • the second intersection 16a may be configured to be located closer to the bottom surface 111a than a straight line Ra passing through the first intersection 15a and the axial center C.
  • a straight line Ra passing through the first intersection 15a and the axial center C Even if one side surface 111b of the pair of side surfaces 111b is an inclined surface inclined to the outer surface of the core 11, and the other side surface 111b of the pair of side surfaces 111b is a surface perpendicular to the outer surface of the core 11. Good.
  • the technology of the present disclosure can be applied to various electric devices such as an electric motor, an electric blower, and a vacuum cleaner.
  • the technique of the present disclosure is particularly useful for an electric blower or the like mounted on a vacuum cleaner or the like that rotates a rotating fan such as a centrifugal fan at a high speed.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • General Engineering & Computer Science (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
  • Iron Core Of Rotating Electric Machines (AREA)
  • Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)
  • Manufacture Of Motors, Generators (AREA)
  • Electric Suction Cleaners (AREA)

Abstract

This electric motor is provided with: a rotor; and a shaft which is fixed to the rotor and extends in an axial direction of the rotor. The rotor has: a core in which a plurality of teeth are formed; and coils disposed between neighboring teeth. The core has a first recess part in which an outer surface of the core is partially recessed. The first recess part has a bottom surface and a pair of side surfaces that face each other in the rotation direction of the rotor. In a cross-section having the axis as the normal line, at least one side surface among the pair of side surfaces has a first intersection point that crosses the outer surface of the core and a second intersection point that crosses the bottom surface. The angle between the bottom surface and a straight line that passes through the first intersection point and the second intersection point is an obtuse angle.

Description

電動機、電動送風機、電気掃除機およびエアタオルElectric motor, electric blower, electric vacuum cleaner and air towel
　本開示は、電動機、電動送風機、電気掃除機およびエアタオルに関する。本開示は、特に、家庭用電気機器等に使用される電動機、この電動機を用いた電動送風機、並びに、この電動送風機を用いた電気掃除機およびエアタオル等の電気機器に関する。 The present disclosure relates to an electric motor, an electric blower, a vacuum cleaner, and an air towel. The present disclosure particularly relates to an electric motor used for household electric appliances and the like, an electric blower using the electric motor, and electric appliances such as a vacuum cleaner and an air towel using the electric blower.
　電動機は、例えば電気掃除機に搭載される電動送風機に用いられる。電動送風機の回転ファンとしては、高い吸引圧力が得られる遠心ファンが用いられている。遠心ファンは、電動機のシャフト（回転軸）に固定されており、高速で回転することにより風圧を発生させる。 The electric motor is used, for example, for an electric blower mounted on a vacuum cleaner. As a rotary fan of the electric blower, a centrifugal fan capable of obtaining a high suction pressure is used. The centrifugal fan is fixed to the shaft (rotary shaft) of the motor and generates wind pressure by rotating at high speed.
　電動送風機では、駆動時の振動を低減することが重要である。電動送風機の振動は、電動機が有する回転子の回転方向における重量バランスの偏りによって生じる。つまり、回転子の重心が回転軸から偏芯すると、回転子の回転によって重心と回転軸との距離に比例した遠心力が発生し、回転子の回転バランスが崩れて電動送風機に振動が発生する。遠心力は回転数の二乗に比例するため、特に回転子が高速回転すると遠心力も大きくなり、振動が大きくなる。 In the electric blower, it is important to reduce the vibration at the time of driving. The vibration of the electric blower is caused by the weight balance deviation in the rotational direction of the rotor of the motor. That is, when the center of gravity of the rotor is decentered from the rotation axis, the rotation of the rotor generates a centrifugal force proportional to the distance between the center of gravity and the rotation axis, the rotation balance of the rotor is lost, and vibration occurs in the electric blower . Since the centrifugal force is proportional to the square of the number of rotations, especially when the rotor rotates at high speed, the centrifugal force also increases and the vibration increases.
　そこで、従来、電動機が有する回転子の重量バランスの偏りを軽減する技術が提案されている（例えば特許文献１を参照）。特許文献１には、回転子を成すコアの外周部の一部を切削することによって重心バランスを修正していることが、開示されている。 Therefore, conventionally, a technique has been proposed to reduce the deviation of the weight balance of the rotor that the motor has (see, for example, Patent Document 1). Patent Document 1 discloses that the center-of-gravity balance is corrected by cutting a part of the outer peripheral portion of the core forming the rotor.
　近年、電気掃除機に対する低騒音の要求から、電動送風機に搭載される電動機の騒音を抑制することが求められている。しかしながら、従来の電動機を用いた電動送風機では、十分に騒音を低減することができない。特に、重心バランスを修正して振動を低減するために、回転子を成すコアの外周部の一部を切削すると、電動機の回転数の偶数倍（２倍、４倍）の周波数に起因する音が発生することが判明した。 In recent years, from the demand for low noise to a vacuum cleaner, it is required to suppress the noise of the motor mounted on the electric blower. However, noise can not be sufficiently reduced with a motor-driven blower using a conventional motor. In particular, when a portion of the outer peripheral portion of the core forming the rotor is cut to correct the balance of the center of gravity and reduce the vibration, the sound resulting from the frequency that is an even multiple (2 or 4) of the rotation speed of the motor Was found to occur.
日本国特許第３４０６８３８号公報Japanese Patent No. 3406838
　本開示は、このような問題を解決するためになされたものであり、低騒音の電動機等を提供することを目的とする。 The present disclosure is made to solve such a problem, and it is an object of the present disclosure to provide a low noise motor and the like.
　上記目的を達成するために、本開示に係る電動機の一態様は、回転子と、回転子に固定されるとともに、回転子の軸心方向に延伸したシャフトと、を備える。回転子は、複数のティースが形成されたコアと、隣り合うティースの間に配置されたコイルとを有する。コアは、コアの外面の一部を窪ませた第１凹部を有する。第１凹部は、底面と、回転子の回転方向に対面する一対の側面とを有する。軸心を法線とする断面において、一対の側面のうち少なくとも一方は、コアの外面と交差する第１交点と、底面と交差する第２交点とを有し、第１交点と第２交点とを通る直線と底面とのなす角度は鈍角である。なお、以下の説明において、回転子の軸心方向とは、回転子の軸心が延伸する方向をいう。 In order to achieve the above object, one aspect of a motor according to the present disclosure includes a rotor, and a shaft fixed to the rotor and extending in the axial direction of the rotor. The rotor has a core in which a plurality of teeth are formed, and a coil disposed between adjacent teeth. The core has a first recess in which a portion of the outer surface of the core is recessed. The first recess has a bottom surface and a pair of side surfaces facing in the rotational direction of the rotor. In a cross section normal to the axis, at least one of the pair of side surfaces has a first intersection intersecting the outer surface of the core and a second intersection intersecting the bottom, and the first intersection and the second intersection The angle between the straight line passing through and the bottom is an obtuse angle. In the following description, the axial direction of the rotor refers to the direction in which the axial center of the rotor extends.
　また、本開示に係る電動送風機の一態様は、上記の電動機と、電動機が備えるシャフトに取り付けられた回転ファンと、を備える。 Moreover, one aspect of the electric blower according to the present disclosure includes the above-described electric motor, and a rotating fan attached to a shaft included in the electric motor.
　また、本開示に係る電気掃除機の一態様は、上記の電動送風機と、電動送風機を制御する制御部と、を備える。 Moreover, the one aspect | mode of the vacuum cleaner which concerns on this indication is provided with said electric blower and the control part which controls an electric blower.
　また、本開示に係るエアタオルの一態様は、上記の電動送風機と、電動送風機を制御する制御部と、を備える。 Further, one aspect of the air towel according to the present disclosure includes the above-described electric blower and a control unit that controls the electric blower.
　本開示に係る電動機によれば、重量バランスの偏りによって生じる振動を抑制しつつ、風切り音を抑制できる。したがって、低騒音の電動機等を実現することができる。 According to the motor according to the present disclosure, it is possible to suppress wind noise while suppressing the vibration caused by the deviation of the weight balance. Therefore, a low noise motor and the like can be realized.
図１は、実施の形態に係る電動送風機の外観斜視図である。FIG. 1 is an external perspective view of the electric blower according to the embodiment. 図２は、実施の形態に係る電動送風機の半断面図である。FIG. 2 is a half sectional view of the electric blower according to the embodiment. 図３は、実施の形態に係る電動送風機の分解図である。FIG. 3 is an exploded view of the electric blower according to the embodiment. 図４は、実施の形態に係る電動機が備える回転子周辺の構造を示す斜視図である。FIG. 4 is a perspective view showing a structure around a rotor provided in the motor according to the embodiment. 図５は、実施の形態に係る電動機が備える回転子の要部拡大断面図である。FIG. 5: is a principal part expanded sectional view of the rotor with which the electric motor which concerns on embodiment is provided. 図６は、図５の破線で囲まれる領域ＶＩの拡大図である。FIG. 6 is an enlarged view of a region VI surrounded by a broken line in FIG. 図７は、回転子のコアを切削して凹部を形成するときの従来の切削方法を説明するための図である。FIG. 7 is a view for explaining a conventional cutting method when cutting a core of a rotor to form a recess. 図８は、図７の破線で囲まれる領域ＶＩＩＩの拡大図である。FIG. 8 is an enlarged view of a region VIII surrounded by a broken line in FIG. 図９は、回転子のコアを切削して凹部を形成するときの実施の形態に係る切削方法を説明するための図である。FIG. 9 is a view for explaining the cutting method according to the embodiment when cutting the core of the rotor to form a recess. 図１０は、従来の電動送風機における振動数と音圧との関係を示す図である。FIG. 10 is a diagram showing the relationship between the frequency and the sound pressure in the conventional electric fan. 図１１は、実施の形態に係る電動送風機における振動数と音圧との関係を示す図である。FIG. 11 is a diagram showing the relationship between the frequency and the sound pressure in the electric fan according to the embodiment. 図１２は、実施の形態の一例に係る電動機が備える回転子に形成された第１凹部の構成を示す断面図である。FIG. 12 is a cross-sectional view showing the configuration of the first recess formed in the rotor provided in the motor according to an example of the embodiment. 図１３は、実施の形態の他の例に係る電動機が備える回転子に形成された第１凹部の構成を示す断面図である。FIG. 13 is a cross-sectional view showing a configuration of a first recess formed in a rotor provided to a motor according to another example of the embodiment. 図１４は、実施の形態に係る電動送風機を用いた電気掃除機の一例を示す模式図である。FIG. 14 is a schematic view showing an example of a vacuum cleaner using the electric blower according to the embodiment. 図１５は、実施の形態に係る電動送風機を用いたエアタオルの一例を示す模式図である。FIG. 15 is a schematic view showing an example of an air towel using the electric blower according to the embodiment. 図１６は、変形例に係る電動機が備える回転子に形成された第１凹部の構成を示す断面図である。FIG. 16 is a cross-sectional view showing a configuration of a first recess formed in a rotor provided in a motor according to a modification. 図１７は、変形例に係る電動機が備える回転子に形成された第１凹部の構成を示す断面図である。FIG. 17 is a cross-sectional view showing the configuration of the first recess formed in the rotor provided in the motor according to the modification. 図１８は、変形例に係る電動機が備える回転子に形成された第１凹部の構成を示す断面図である。FIG. 18 is a cross-sectional view showing a configuration of a first recess formed in a rotor provided in a motor according to a modification. 図１９は、変形例に係る電動機が備える回転子に形成された第１凹部の構成を示す断面図である。FIG. 19 is a cross-sectional view showing the configuration of the first recess formed in the rotor provided in the motor according to the modification. 図２０は、変形例に係る電動機が備える回転子に形成された第１凹部の構成を示す断面図である。FIG. 20 is a cross-sectional view showing the configuration of the first recess formed in the rotor provided in the motor according to the modification. 図２１は、変形例に係る電動機が備える回転子に形成された第１凹部の構成を示す断面図である。FIG. 21 is a cross-sectional view showing a configuration of a first recess formed in a rotor provided in a motor according to a modification. 図２２は、変形例に係る電動機が備える回転子に形成された第１凹部の構成を示す断面図である。FIG. 22 is a cross-sectional view showing the configuration of the first recess formed in the rotor provided in the motor according to the modification. 図２３は、変形例に係る電動機が備える回転子に形成された第１凹部の構成を示す断面図である。FIG. 23 is a cross-sectional view showing the configuration of the first recess formed in the rotor provided in the motor according to the modification.
　以下、本開示の実施の形態について、図面を参照しながら説明する。なお、以下に説明する実施の形態は、いずれも本開示の一具体例を示すものである。したがって、以下の実施の形態で示される、数値、形状、材料、構成要素、構成要素の配置位置および接続形態等は、一例であって本開示を限定する主旨ではない。よって、以下の実施の形態における構成要素のうち、本開示の最上位概念を示す独立請求項に記載されていない構成要素については、任意の構成要素として説明される。 Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Each embodiment described below shows one specific example of the present disclosure. Therefore, numerical values, shapes, materials, components, arrangement positions of components, connection configurations, and the like shown in the following embodiments are merely examples, and are not intended to limit the present disclosure. Therefore, among the components in the following embodiments, components that are not described in the independent claims indicating the highest concept of the present disclosure are described as optional components.
　なお、各図は、模式図であり、必ずしも厳密に図示されたものではない。また、各図において、実質的に同一の構成に対しては同一の符号を付しており、重複する説明は省略または簡略化する。 Each drawing is a schematic view and is not necessarily strictly illustrated. Further, in the respective drawings, substantially the same configuration is given the same reference numeral, and overlapping description will be omitted or simplified.
　（実施の形態）
　図１～図３を用いて、実施の形態に係る電動送風機１および電動送風機１に用いられる電動機２について説明する。図１は、実施の形態に係る電動送風機１の外観斜視図である。図２は、同電動送風機１の半断面図である。図３は、同電動送風機１の分解図である。なお、図２に示される矢印は、回転ファン３の回転により電動送風機１内に吸引される空気の流れを示している。 Embodiment
The electric blower 1 according to the embodiment and the electric motor 2 used for the electric blower 1 will be described with reference to FIGS. 1 to 3. FIG. 1 is an external perspective view of the electric blower 1 according to the embodiment. FIG. 2 is a half sectional view of the electric blower 1. FIG. 3 is an exploded view of the electric blower 1. The arrows shown in FIG. 2 indicate the flow of air drawn into the electric blower 1 by the rotation of the rotary fan 3.
　図１～図３に示すように、本実施の形態における電動送風機１は、電動機２（モータ）と、回転ファン３と、エアガイド４と、ブラケット５と、フレーム６と、ファンケース７とを備える。 As shown in FIGS. 1 to 3, the electric blower 1 in the present embodiment includes a motor 2 (motor), a rotary fan 3, an air guide 4, a bracket 5, a frame 6 and a fan case 7. Prepare.
　電動機２は、回転負荷として回転ファン３を回転させる。電動機２の詳細な構成については後述する。 The motor 2 rotates the rotating fan 3 as a rotating load. The detailed configuration of the motor 2 will be described later.
　回転ファン３は、フレーム６とファンケース７とにより構成される外郭筐体（ハウジング）内に空気を吸引する。回転ファン３は、電動機２が有するシャフト３０の所定の部位に取り付けられており、シャフト３０が回転することで回転する。本実施の形態において、回転ファン３は、ブラケット５から突出したシャフト３０の先端部に取り付けられている。一例として、回転ファン３は、高い吸引圧力が得られる遠心ファンである。回転ファン３が回転することにより、風圧が発生し、ファンケース７の吸気口７ａから空気が吸い込まれる。 The rotating fan 3 sucks air into an outer housing (housing) constituted by the frame 6 and the fan case 7. The rotation fan 3 is attached to a predetermined portion of a shaft 30 of the motor 2 and rotates by the rotation of the shaft 30. In the present embodiment, the rotary fan 3 is attached to the tip of the shaft 30 protruding from the bracket 5. As an example, the rotary fan 3 is a centrifugal fan that can obtain high suction pressure. The rotation of the rotary fan 3 generates a wind pressure, and air is sucked from the air inlet 7 a of the fan case 7.
　エアガイド４は、回転ファン３の外周に通風路を形成する。エアガイド４は、回転ファン３を囲むようにリング状に形成されている。エアガイド４は、気体の流れを整流するためのガイド板として、複数のデュフューザ翼４ａを有する。エアガイド４は、回転ファン３の回転によってファンケース７の吸気口７ａから吸引された空気の流れを整流して旋回流を生成し、吸引した気体をフレーム６へと滑らかに流し込む。 The air guide 4 forms an air passage around the outer periphery of the rotary fan 3. The air guide 4 is formed in a ring shape so as to surround the rotary fan 3. The air guide 4 has a plurality of diffuser blades 4a as a guide plate for rectifying the flow of gas. The air guide 4 rectifies the flow of air drawn from the air inlet 7 a of the fan case 7 by the rotation of the rotary fan 3 to generate a swirling flow, and smoothly flows the drawn gas into the frame 6.
　ブラケット５は、エアガイド４とともにフレーム６の開口部を覆っている。ブラケット５は、第１軸受け部６０を覆うように配置されている。ブラケット５には、開口部が形成されており、エアガイド４で整流された空気は、ブラケット５の開口部を通過してフレーム６内に流入する。 The bracket 5 covers the opening of the frame 6 together with the air guide 4. The bracket 5 is disposed to cover the first bearing portion 60. An opening is formed in the bracket 5, and the air rectified by the air guide 4 passes through the opening of the bracket 5 and flows into the frame 6.
　フレーム６は、電動機２を収納する第１筐体である。フレーム６の底部には、回転ファン３の回転によって吸引した空気を排出する複数の排気口６ａが形成されている。 The frame 6 is a first housing for housing the motor 2. At the bottom of the frame 6, a plurality of exhaust ports 6 a for discharging the air sucked by the rotation of the rotary fan 3 are formed.
　ファンケース７は、回転ファン３を収納する第２筐体である。ファンケース７は、回転ファン３、エアガイド４およびブラケット５を覆うようにフレーム６に固定されている。ファンケース７は、外気を吸引するための吸気口７ａを有している。 The fan case 7 is a second housing that houses the rotary fan 3. The fan case 7 is fixed to the frame 6 so as to cover the rotary fan 3, the air guide 4 and the bracket 5. The fan case 7 has an air inlet 7a for suctioning the outside air.
　次に、電動機２の詳細な構成について説明する。図２に示すように、本実施の形態における電動機２は、ブラシ付き整流子電動機であって、回転子１０と、固定子２０と、シャフト３０と、整流子４０と、ブラシ５０と、第１軸受け部６０と、第２軸受け部７０とを備える。 Next, the detailed configuration of the motor 2 will be described. As shown in FIG. 2, the motor 2 in the present embodiment is a brushed commutator motor, and includes a rotor 10, a stator 20, a shaft 30, a commutator 40, a brush 50, and a first motor. A bearing portion 60 and a second bearing portion 70 are provided.
　回転子１０（ロータ）は、固定子２０による磁力によって、シャフト３０を回転中心として回転する。本実施の形態において、回転子１０は、インナーロータである。回転子１０は、図２に示すように、固定子２０の内側に配置されている。具体的には、回転子１０は、固定子２０との間に微小なエアギャップを介して、固定子２０に囲まれている。回転子１０は、例えば、４０，０００ｒｐｍ（ｒｅｖｏｌｕｔｉｏｎｓ　ｐｅｒ　ｍｉｎｕｔｅ）で高速回転する。 The rotor 10 (rotor) rotates around the shaft 30 by the magnetic force of the stator 20. In the present embodiment, the rotor 10 is an inner rotor. The rotor 10 is disposed inside the stator 20, as shown in FIG. Specifically, the rotor 10 is surrounded by the stator 20 via a minute air gap with the stator 20. The rotor 10 rotates at a high speed, for example, at 40,000 rpm (revolutions per minute).
　固定子２０（ステータ）は、回転子１０に作用する磁力を発生させる。本実施の形態において、固定子２０は、回転子１０を囲むように配置されている。固定子２０は、例えば、Ｓ極およびＮ極を有する永久磁石によって構成されているが、コア（ステータコア）と巻線コイル（ステータコイル）とによって構成されていてもよい。固定子２０は、例えば、フレーム６に固定されている。 The stator 20 (stator) generates a magnetic force acting on the rotor 10. In the present embodiment, the stator 20 is disposed to surround the rotor 10. The stator 20 is constituted by, for example, a permanent magnet having an S pole and an N pole, but may be constituted by a core (stator core) and a winding coil (stator coil). The stator 20 is fixed to, for example, the frame 6.
　シャフト３０は、回転子１０が回転する際の中心となる回転軸である。シャフト３０は、軸心Ｃ方向である長手方向に延伸している。シャフト３０は、例えば金属棒によって構成される。シャフト３０は、回転子１０に固定されている。具体的には、シャフト３０は、例えば、回転子１０の両側に延在するように、回転子１０のコア１１の中心を貫いた状態で、コア１１に固定されている。一例として、シャフト３０は、回転子１０のコア１１に圧入されている。 The shaft 30 is a rotation axis serving as a center when the rotor 10 rotates. The shaft 30 extends in the longitudinal direction which is the axial center C direction. The shaft 30 is formed of, for example, a metal rod. The shaft 30 is fixed to the rotor 10. Specifically, the shaft 30 is fixed to the core 11 in a state of penetrating the center of the core 11 of the rotor 10 so as to extend on both sides of the rotor 10, for example. As an example, the shaft 30 is press-fit into the core 11 of the rotor 10.
　シャフト３０は、回転子１０を貫通しており、回転子１０の両側に延在するように配置されている。シャフト３０が有する一方の端部（回転ファン３側の端部）は、第１軸受け部６０に支持されている。シャフト３０が有する他方の端部は、第２軸受け部７０に支持されている。一例として、第１軸受け部６０および第２軸受け部７０は、シャフト３０を支持するベアリングである。このように、シャフト３０は、第１軸受け部６０と第２軸受け部７０とによって、回転自在となるように両端部が保持されている。 The shaft 30 passes through the rotor 10 and is disposed to extend on both sides of the rotor 10. One end (the end on the rotary fan 3 side) of the shaft 30 is supported by the first bearing portion 60. The other end of the shaft 30 is supported by the second bearing portion 70. As an example, the first bearing portion 60 and the second bearing portion 70 are bearings that support the shaft 30. As described above, the shaft 30 is held by the first bearing portion 60 and the second bearing portion 70 so as to be rotatable.
　シャフト３０の一方の端部は、第１軸受け部６０から突出するとともに、ブラケット５を貫通している。ブラケット５から突出したシャフト３０の先端部には、回転ファン３が取り付けられている。 One end of the shaft 30 protrudes from the first bearing portion 60 and penetrates the bracket 5. The rotating fan 3 is attached to the tip of the shaft 30 protruding from the bracket 5.
　整流子４０は、シャフト３０に取り付けられている。本実施の形態において、整流子４０は、シャフト３０における回転子１０と第２軸受け部７０との間の部分に固定されている。整流子４０は、回転子１０が有するコイル１２と電気的に接続されており、ブラシ５０と摺接する。整流子４０は、シャフト３０の回転方向に互いに絶縁分離された複数のセグメントによって構成されている。 The commutator 40 is attached to the shaft 30. In the present embodiment, the commutator 40 is fixed to a portion of the shaft 30 between the rotor 10 and the second bearing portion 70. The commutator 40 is electrically connected to the coil 12 of the rotor 10 and is in sliding contact with the brush 50. The commutator 40 is constituted by a plurality of segments insulated and separated from each other in the rotational direction of the shaft 30.
　ブラシ５０は、整流子４０に接触することで回転子１０に電力を供給するための給電ブラシである。ブラシ５０は、整流子４０に接触することで整流子４０に電機子電流を供給する。一例として、ブラシ５０は、カーボンブラシである。また、ブラシ５０は、長尺状の実質的な直方体である。 The brush 50 is a power supply brush for supplying power to the rotor 10 by contacting the commutator 40. The brush 50 contacts the commutator 40 to supply armature current to the commutator 40. As an example, the brush 50 is a carbon brush. Moreover, the brush 50 is a long substantially rectangular parallelepiped.
　ブラシ５０は、整流子４０に摺接可能に配置されている。ブラシ５０は、一対設けられており、一対のブラシ５０は、整流子４０を挟持するように、整流子４０を挟んで対向して配置されている。具体的には、一対のブラシ５０の内側の先端部は、整流子４０に当接している。本実施の形態において、ブラシ５０の長手方向の内側（シャフト３０側）の端面が整流子４０との接触面となっている。 The brush 50 is disposed slidably on the commutator 40. The brushes 50 are provided as a pair, and the pair of brushes 50 are disposed to face each other across the commutator 40 so as to sandwich the commutator 40. Specifically, the inner front end portions of the pair of brushes 50 are in contact with the commutator 40. In the present embodiment, an end surface on the inner side (shaft 30 side) of the brush 50 in the longitudinal direction is a contact surface with the commutator 40.
　このように構成される電動送風機１では、電動機２の回転子１０が回転すると、回転ファン３が回転する。回転ファン３が回転することによって、ファンケース７の吸気口７ａからファンケース７の内部に空気が吸引され、回転ファン３の中央部から外径側に向かって流れる気流が生じる。ファンケース７の内部に吸引された空気は、エアガイド４が有するデュフューザ翼４ａによってファンケース７の外周部へと導かれてエアガイド４とファンケース７との空隙部で旋回流となり、ブラケット５の開口部を介してフレーム６内に流入する。流入した旋回流は、電動機２が有する回転子１０および固定子２０を冷却しながら、フレーム６の排気口６ａから電動送風機１の外に排出される。 In the electric blower 1 configured as described above, when the rotor 10 of the motor 2 rotates, the rotary fan 3 rotates. The rotation of the rotary fan 3 causes air to be drawn into the inside of the fan case 7 from the air inlet 7 a of the fan case 7, thereby generating an air flow from the central portion of the rotary fan 3 toward the outer diameter side. The air drawn into the inside of the fan case 7 is guided to the outer peripheral portion of the fan case 7 by the diffuser 4a of the air guide 4 and becomes a swirling flow at the gap between the air guide 4 and the fan case 7. Flows into the frame 6 through the opening of The inflowing swirling flow is discharged from the exhaust port 6 a of the frame 6 to the outside of the electric blower 1 while cooling the rotor 10 and the stator 20 of the motor 2.
　このとき、フレーム６に流入した空気は、フレーム６内の隙間（固定子２０とフレーム６との隙間、回転子１０と固定子２０との隙間等）を通過して、フレーム６が有する排気口６ａから排出される。 At this time, the air flowing into the frame 6 passes through the gap in the frame 6 (the gap between the stator 20 and the frame 6, the gap between the rotor 10 and the stator 20, etc.), and the exhaust port of the frame 6 It is discharged from 6a.
　次に、電動機２が有する回転子１０の詳細な構成について、図４および図５を用いて説明する。図４は、実施の形態に係る電動機２が備える回転子１０周辺の構造を示す斜視図である。図５は、同電動機２が備える回転子１０の要部拡大断面図である。なお、図４において、矢印Ｗは、回転子１０の周辺を通過する空気の流れを示しており、矢印Ｒは、シャフト３０の回転方向を示している。 Next, the detailed configuration of the rotor 10 of the motor 2 will be described with reference to FIGS. 4 and 5. FIG. 4 is a perspective view showing the structure around the rotor 10 provided in the motor 2 according to the embodiment. FIG. 5: is a principal part expanded sectional view of the rotor 10 with which the motor 2 is provided. In FIG. 4, the arrow W indicates the flow of air passing around the rotor 10, and the arrow R indicates the rotation direction of the shaft 30.
　図４および図５に示すように、回転子１０は、複数のティース１１ａが形成されたコア１１（ロータコア）と、隣り合うティース１１ａの間に配置されたコイル１２（ロータコイル）とを有する。 As shown to FIG. 4 and FIG. 5, the rotor 10 has the core 11 (rotor core) in which several teeth 11a were formed, and the coil 12 (rotor coil) arrange | positioned between the adjacent teeth 11a.
　なお、以下の説明において、ティース（ｔｅｅｔｈ：ｔｏｏｔｈの複数形）あるいはトゥース（ｔｏｏｔｈ）という用語の使い分けを行っている。具体的には、円環状のステータコアの中心方向に突出する複数の歯部は、ティースと記す。ステータコアの複数の歯部のうち、一つの歯部については、トゥース（ｔｏｏｔｈ）と記す。 In the following description, the term teeth (tooth: plural form) or tooth (tooth) is used properly. Specifically, the plurality of teeth projecting in the center direction of the annular stator core is referred to as teeth. One tooth of the plurality of teeth of the stator core is referred to as a tooth.
　図４に示すように、コア１１は、複数の電磁鋼板がシャフト３０の軸心方向に積層された積層体によって構成されている。コア１１を構成する電磁鋼板は、例えば、打ち抜き電磁鋼板であり、互いに同一形状および同一厚さである。複数の電磁鋼板は、例えばかしめによって互いに固定されている。なお、コア１１は、複数の電磁鋼板の積層体ではなく、磁性材料のバルク体であってもよい。 As shown in FIG. 4, the core 11 is formed of a laminate in which a plurality of electromagnetic steel plates are stacked in the axial direction of the shaft 30. The electromagnetic steel plates constituting the core 11 are, for example, punched electromagnetic steel plates, and have the same shape and the same thickness. The plurality of magnetic steel sheets are fixed to one another, for example, by caulking. The core 11 may be a bulk body of a magnetic material instead of a laminate of a plurality of electromagnetic steel sheets.
　図４に示すように、コア１１に形成された複数のティース１１ａは、回転子１０の回転方向に沿って、コア１１の全周にわたって、所定の間隔をあけて設けられている。図５に示すように、各トゥース１１ａは、断面形状が実質的にＴ字状に形成されている。隣り合う２つのティース１１ａの間の空間は、スロット１１ｂ（鉄心溝）を構成している。 As shown in FIG. 4, the plurality of teeth 11 a formed in the core 11 are provided along the rotation direction of the rotor 10 at predetermined intervals over the entire circumference of the core 11. As shown in FIG. 5, each tooth 11a has a substantially T-shaped cross section. A space between two adjacent teeth 11a constitutes a slot 11b (iron core groove).
　コイル１２は、このスロット１１ｂに配置されている。コイル１２は、コア１１に巻回された巻線コイル（界磁巻線）である。コイル１２の巻き方は、重ね巻であってもよいし、集中巻であってもよい。コイル１２は、整流子４０およびブラシ５０を介して互いに電気的に接続されている。 The coil 12 is disposed in the slot 11b. The coil 12 is a winding coil (field winding) wound around the core 11. The winding method of the coil 12 may be lap winding or concentrated winding. The coils 12 are electrically connected to each other via the commutator 40 and the brush 50.
　なお、図５に示すように、各スロット１１ｂの開口部分には、コイル１２を保持するためにウエッジ１３が配置されている。また、各スロット１１ｂ内の各ティース１１ａの表面には、絶縁フィルム１４が設けられている。 In addition, as shown in FIG. 5, in order to hold | maintain the coil 12, the wedge 13 is arrange | positioned in the opening part of each slot 11b. Insulating films 14 are provided on the surfaces of the teeth 11 a in the slots 11 b.
　図４に示すように、コア１１は、コア１１の外面の一部を窪ませた第１凹部１１１および第２凹部１１２を有する。第１凹部１１１および第２凹部１１２は、回転子１０の重心バランスを修正するために、コア１１の外面を部分的に切削することにより形成された切削部である。第１凹部１１１および第２凹部１１２を形成することで、回転子１０の重量バランスの偏りを軽減でき、電動機２の振動を抑制できる。具体的には、第１凹部１１１および第２凹部１１２は、コア１１が有する複数のティース１１ａの外面の一部を窪ませるように各トゥース１１ａを切削することにより形成される。 As shown in FIG. 4, the core 11 has a first recess 111 and a second recess 112 in which a part of the outer surface of the core 11 is recessed. The first recess 111 and the second recess 112 are cutting portions formed by partially cutting the outer surface of the core 11 in order to correct the center of gravity balance of the rotor 10. By forming the first recess 111 and the second recess 112, it is possible to reduce the deviation of the weight balance of the rotor 10 and to suppress the vibration of the motor 2. Specifically, the first recess 111 and the second recess 112 are formed by cutting each tooth 11 a so as to lower a part of the outer surface of the plurality of teeth 11 a of the core 11.
　図５に示すように、第１凹部１１１は、底面１１１ａと、回転子１０の回転方向に対面する一対の側面１１１ｂとを有する。第１凹部１１１における回転子１０の回転方向の両端部には、側面１１１ｂとコア１１の外面とで構成される段差が形成されている。つまり、第１凹部１１１を形成することで、コア１１に２つの段差が形成される。 As shown in FIG. 5, the first recess 111 has a bottom surface 111 a and a pair of side surfaces 111 b facing in the rotational direction of the rotor 10. At both end portions of the first recess 111 in the rotational direction of the rotor 10, steps formed of the side surface 111b and the outer surface of the core 11 are formed. That is, by forming the first recess 111, two steps are formed in the core 11.
　第１凹部１１１は、回転子１０の重量をダイナミックに調整するために、コア１１を広範囲に切削することにより形成される。このため、第１凹部１１１は、連続する複数のティース１１ａにわたって形成されているとともに、シャフト３０の長手方向のコア１１の端部に設けられている。 The first recess 111 is formed by cutting the core 11 extensively to adjust the weight of the rotor 10 dynamically. For this reason, the first recess 111 is formed across the plurality of continuous teeth 11 a and provided at the end of the core 11 in the longitudinal direction of the shaft 30.
　図４に示すように、本実施の形態において、第１凹部１１１は、コア１１の整流子４０側とは反対側の端部（回転ファン３側の端部）に形成されている。また、図５に示すように、第１凹部１１１は、連続する５つのティース１１ａにわたって形成されている。この場合、第１凹部１１１の底面１１１ａは、連続する５つのティース１１ａの全てに存在する。第１凹部１１１の側面１１１ｂは、連続する５つのティース１１ａのうちの両端部のティース１１ａの各々に存在する。つまり、連続する５つのティース１１ａのうちの両端部の２つ除く３つのティース１１ａについては、底面１１１ａおよび側面１１１ｂのうち底面１１１ａのみが存在する。当然のことながら、底面１１１ａのみが存在するトゥース１１ａは、例示する３つに限定されない。なお、この３つのティース１１ａの底面１１１ａは、各トゥース１１ａの回転子１０の回転方向に沿った全域に存在している。 As shown in FIG. 4, in the present embodiment, the first concave portion 111 is formed at an end of the core 11 opposite to the side of the commutator 40 (an end of the rotary fan 3). Moreover, as shown in FIG. 5, the 1st recessed part 111 is formed over the continuous 5 teeth 11a. In this case, the bottom surface 111a of the first recess 111 is present in all five consecutive teeth 11a. The side surface 111b of the 1st recessed part 111 exists in each of the teeth 11a of the both ends of five continuous teeth 11a. That is, with respect to three teeth 11a except two of the two end portions of the five consecutive teeth 11a, only the bottom surface 111a exists among the bottom surface 111a and the side surface 111b. Naturally, the tooth 11a in which only the bottom surface 111a is present is not limited to three as illustrated. The bottom surfaces 111a of the three teeth 11a are present in the entire region along the rotation direction of the rotor 10 of each tooth 11a.
　図６は、図５の破線で囲まれる領域ＶＩの拡大図である。図５および図６に示すように、シャフト３０の軸心Ｃを法線とする断面において、外周線１５は、コア１１の外面を含む。内周線１６は、第１凹部１１１の底面１１１ａを含む。側面１１１ｂは、その一端が外周線１５と交差し、その他端が内周線１６と交差する。第１交点１５ａは、外周線１５と側面１１１ｂとの交点である。第２交点１６ａは、内周線１６と側面１１１ｂとの交点である。ここで、第１交点１５ａと第２交点１６ａとを通る直線をＲｂとする。直線Ｒｂと底面１１１ａとがなす角度θ１は、鈍角である。 FIG. 6 is an enlarged view of a region VI surrounded by a broken line in FIG. As shown in FIGS. 5 and 6, in a cross section normal to the axial center C of the shaft 30, the outer circumferential line 15 includes the outer surface of the core 11. The inner circumferential line 16 includes the bottom surface 111 a of the first recess 111. One end of the side surface 111 b intersects the outer circumferential line 15, and the other end intersects the inner circumferential line 16. The first intersection point 15a is an intersection point of the outer peripheral line 15 and the side surface 111b. The second intersection 16a is an intersection of the inner circumferential line 16 and the side surface 111b. Here, a straight line passing the first intersection point 15a and the second intersection point 16a is taken as Rb. An angle θ1 formed by the straight line Rb and the bottom surface 111a is an obtuse angle.
　他の言い方をすれば、シャフト３０の軸心Ｃを法線とする断面において、第１交点１５ａと軸心Ｃとを通る直線をＲａとすると、第２交点１６ａは、第１交点１５ａと軸心Ｃとを通る直線Ｒａよりも底面１１１ａ側に位置している。 In other words, in a cross section having the axis C of the shaft 30 as a normal, assuming that a straight line passing the first intersection 15a and the axis C is Ra, the second intersection 16a is the first intersection 15a and the axis It is located closer to the bottom surface 111 a than a straight line Ra passing through the heart C.
　つまり、第１凹部１１１におけるコア１１の外面との切削境界の段差の角が９０°になっていない。シャフト３０の軸心Ｃを法線とする断面とは、軸心Ｃと交差する断面ともいう。 That is, the angle of the step of the cutting boundary with the outer surface of the core 11 in the first recess 111 is not 90 °. The cross section having the axis C of the shaft 30 as a normal is also referred to as a cross section intersecting the axis C.
　具体的には、一対の側面１１１ｂの各々は、シャフト３０の軸心Ｃを法線とする断面において、回転子１０の回転方向に沿って深さが変化する部位を含んでいる。一例として、一対の側面１１１ｂの各々はテーパ面であり、各側面１１１ｂは、面全体として回転子１０の回転方向に沿って深さが変化する部位となっている。つまり、各側面１１１ｂは、回転子１０の回転方向に沿って深さが漸次浅くなる傾斜面となっている。本実施の形態において、各側面１１１ｂのテーパ角θ２（傾斜角）は、鋭角である４５°である。すなわち、各側面１１１ｂと底面１１１ａとのなす角θ１は、鈍角である１３５°である。 Specifically, each of the pair of side surfaces 111 b includes, in a cross-section normal to the axial center C of the shaft 30, a portion whose depth changes along the rotation direction of the rotor 10. As an example, each of the pair of side surfaces 111 b is a tapered surface, and each side surface 111 b is a portion whose depth changes along the rotation direction of the rotor 10 as a whole surface. That is, each side surface 111 b is an inclined surface whose depth gradually decreases along the rotation direction of the rotor 10. In the present embodiment, the taper angle θ2 (inclination angle) of each side surface 111b is 45 ° which is an acute angle. That is, an angle θ1 between each side surface 111b and the bottom surface 111a is 135 ° which is an obtuse angle.
　また、図５に示すように、第１凹部１１１は、シャフト３０の軸心Ｃを法線とする断面において、線対称形状となっている。したがって、一対の側面１１１ｂは、順テーパ面となっており、いずれも同じテーパ角を有する。 Further, as shown in FIG. 5, the first recess 111 has a line-symmetrical shape in a cross section with the axis C of the shaft 30 as a normal. Therefore, the pair of side surfaces 111 b are forward tapered surfaces, and both have the same taper angle.
　図４に示すように、第２凹部１１２は、回転子１０の重量を微調整するために、コア１１を小範囲に切削することにより形成される。具体的には、第２凹部１１２は、第１凹部１１１を形成した後に、回転子１０の重心位置を微調整するために形成される。このため、第２凹部１１２の切削量は第１凹部１１１の切削量よりも小さい。一例として、第２凹部１１２は、Ｖ字溝である。つまり、第２凹部１１２の断面形状は、シャフト３０の軸心Ｃを法線とする断面においてＶ字である。あるいは、第２凹部１１２の断面形状は、シャフト３０の軸心Ｃを法線とする断面においてＵ字である。 As shown in FIG. 4, the second recess 112 is formed by cutting the core 11 into a small area in order to finely adjust the weight of the rotor 10. Specifically, the second recess 112 is formed to finely adjust the position of the center of gravity of the rotor 10 after the first recess 111 is formed. For this reason, the cutting amount of the second recess 112 is smaller than the cutting amount of the first recess 111. As an example, the second recess 112 is a V-shaped groove. That is, the cross-sectional shape of the second recess 112 is V-shaped in a cross section with the axis C of the shaft 30 as a normal. Alternatively, the cross-sectional shape of the second recess 112 is U-shaped in a cross section with the axis C of the shaft 30 as a normal.
　第２凹部１１２は、シャフト３０の長手方向におけるコア１１の中央部に設けられている。第２凹部１１２は、第１凹部１１１が形成されたティース１１ａとは異なるトゥース１１ａに形成されているが、第１凹部１１１が形成されたティース１１ａに形成されていてもよい。 The second recess 112 is provided at the central portion of the core 11 in the longitudinal direction of the shaft 30. Although the 2nd crevice 112 is formed in tooth 11a different from teeth 11a in which the 1st crevice 111 was formed, it may be formed in teeth 11a in which the 1st crevice 111 was formed.
　次に、本実施の形態に係る電動機２を用いた電動送風機１の作用効果について、本開示に至った経緯も含めて説明する。 Next, the operation and effect of the electric blower 1 using the motor 2 according to the present embodiment will be described, including the background of the present disclosure.
　従来、電動機の振動を抑制するために、電動機が備える回転子の重量バランスの偏りを軽減することが行われている。図７は、回転子のコアを切削して凹部を形成するときの従来の切削方法を説明するための図である。この場合、例えば、図７に示すように、鼓状の切削刃２００Ｘを用いて回転子１０のコア１１の外周部の一部を切削することによって、回転子１０の重心バランスを修正している。このため、重心バランスを修正した後の回転子１０のコア１１には、切削部として凹部１１１Ｘが形成される。 Conventionally, in order to suppress the vibration of the motor, it has been performed to reduce the deviation of the weight balance of the rotor provided in the motor. FIG. 7 is a view for explaining a conventional cutting method when cutting a core of a rotor to form a recess. In this case, for example, as shown in FIG. 7, the balance of the center of gravity of the rotor 10 is corrected by cutting a part of the outer peripheral portion of the core 11 of the rotor 10 using the hourglass-shaped cutting blade 200X. . For this reason, in the core 11 of the rotor 10 after correcting the center-of-gravity balance, a recess 111X is formed as a cutting portion.
　凹部１１１Ｘは、複数のティース１１ａにわたって形成されている。凹部１１１Ｘは、フラット面である底面１１１ｘと、回転子１０の回転方向に対面する一対の側面１１１ｙとを有する。つまり、凹部１１１Ｘの回転子１０の回転方向における両端部には、切削境界として段差が形成されている。凹部１１１Ｘは、回転子１０の回転方向において２つの段差を有する。 The recess 111X is formed across the plurality of teeth 11a. The recess 111 </ b> X has a bottom surface 111 x which is a flat surface, and a pair of side surfaces 111 y facing in the rotational direction of the rotor 10. That is, on both ends of the recess 111X in the rotational direction of the rotor 10, steps are formed as cutting boundaries. The recess 111 </ b> X has two steps in the rotational direction of the rotor 10.
　図８は、図７の破線で囲まれる領域ＶＩＩＩの拡大図である。図８に示すように、凹部１１１Ｘにおいて、側面１１１ｙとコア１１の外面とのなす角が９０°であり、側面１１１ｙ全体が底面１１１ｘに対して垂直になっている。つまり、凹部１１１Ｘにおけるコア１１の外面との切削境界の段差が９０°になっている。 FIG. 8 is an enlarged view of a region VIII surrounded by a broken line in FIG. As shown in FIG. 8, in the recess 111X, the angle between the side surface 111y and the outer surface of the core 11 is 90 °, and the entire side surface 111y is perpendicular to the bottom surface 111x. That is, the step of the cutting boundary with the outer surface of the core 11 in the recess 111X is 90 °.
　ここで、電動送風機については低騒音であることが求められている。電動送風機における騒音は、回転子の重量バランスの偏りによる回転子の振動が一つの要因である。しかし、回転子の振動は、上記のように、回転子のコアの一部を切削して回転子の重心バランスを修正することで、回転子の振動による騒音を抑制することができる。 Here, low noise is required for the electric blower. The noise in the electric blower is one factor that is the vibration of the rotor due to the deviation of the weight balance of the rotor. However, the vibration of the rotor can suppress the noise due to the vibration of the rotor by cutting a part of the core of the rotor and correcting the center-of-gravity balance of the rotor as described above.
　一方、電動送風機における騒音の他の要因として、回転ファンに起因するものもある。回転ファンによって電動送風機から排出される空気については、回転ファンの回転数と回転ファンの翼数との積に対応する周波数の音、いわゆるＮＺ音が発生する。ＮＺ音は、電動送風機の騒音の中では最も音圧が大きい。しかし、エアガイドの通風路形状を工夫することで、ＮＺ音を抑制することは可能である。 On the other hand, another cause of noise in the electric blower is that caused by the rotating fan. As air discharged from the electric blower by the rotary fan, a sound of a frequency corresponding to the product of the number of rotations of the rotary fan and the number of blades of the rotary fan, so-called NZ sound is generated. NZ sound has the largest sound pressure among the noises of the electric blower. However, it is possible to suppress NZ noise by devising the air passage shape of the air guide.
　ＮＺ音の次に大きい音の要因は、回転ファンの回転数の偶数倍（２倍、４倍、・・・）の周波数の音である。これまで、回転ファンの回転数の偶数倍の周波数の音の発生要因は、電動機の振動の高調波成分、又は、ブラシと整流子との摺動音であると考えられていた。 The factor behind the NZ sound is a sound with a frequency that is an even multiple (twice, four times,...) Of the rotational speed of the rotary fan. Heretofore, it has been considered that the generation factor of the sound having a frequency that is an even multiple of the rotational speed of the rotary fan is the harmonic component of the vibration of the motor or the sliding noise between the brush and the commutator.
　しかしながら、このような観点で電動機に騒音対策を試みても、回転数の偶数倍の周波数の音を抑制することができなかった。つまり、回転数の偶数倍の周波数の音は、電動機の振動の大きさとの相関性が低く、ブラシバネ圧および整流子の真円度とも相関性が低いことが分かった。 However, even if the noise countermeasure is attempted to the motor from such a viewpoint, it is not possible to suppress the sound of the frequency that is an even multiple of the rotational speed. That is, it has been found that the sound having a frequency that is an even number multiple of the rotational speed has low correlation with the magnitude of vibration of the motor and has low correlation with the brush spring pressure and the roundness of the commutator.
　そこで、本発明者がさらに実験を重ねて検討した結果、回転ファンの回転数の偶数倍の周波数の音は、回転子の重心バランスを修正する際に回転子のコアを切削することで形成される凹部（切削部）との相関性が高いことを、本発明者は突き止めた。具体的には、回転数の偶数倍の周波数の音は、コアの切削により回転子のコアに形成された凹部の段差により生じる風切り音であることが分かった。以下、この風切り音について説明する。 Therefore, as a result of repeated examinations by the inventor of the present invention, as a result, a sound having a frequency that is an even multiple of the rotational speed of the rotating fan is formed by cutting the rotor core when correcting the center of gravity balance of the rotor. The inventor has found that the correlativity with the recessed portion (cutting portion) is high. Specifically, it has been found that the sound having a frequency that is an even multiple of the rotational speed is a wind noise generated by the step of the recess formed in the core of the rotor by cutting the core. The wind noise will be described below.
　回転子の重心バランスを修正する際のコアの切削は、上記のように鼓状の切削刃を用いて行われる。しかし、この場合、１回の切削によってアンバランス量が規定範囲内に収まったときには、凹部における切削境界の段差は、回転子の回転方向の２ヶ所に形成される。 The cutting of the core when correcting the center of gravity balance of the rotor is performed using a drum-shaped cutting blade as described above. However, in this case, when the unbalance amount falls within the specified range by one cutting, the steps of the cutting boundary in the recess are formed at two places in the rotational direction of the rotor.
　１回目のコアの切削によってアンバランス量が規定範囲内に収まらない場合、２回目の切削を行うことがある。あるいは、初期のアンバランス量が大きい場合にも、２回の切削を行うことがある。具体的には、初期のアンバランス量が大きい場合には、コアの切削量を大きくすればよいが、コアの磁気回路および機械強度を確保するためには、凹部の切削深さを規制する必要がある。このため、１回のコアの切削量を大きくするのではなく、切削する位置を分散させて２回に分けてコアの切削を行うことがある。このように、コアの切削を２回行うと、２ヵ所の凹部（切削部）における切削境界の段差は、合計で４ヶ所になる。 If the unbalanced amount does not fall within the specified range due to the first core cutting, the second cutting may be performed. Alternatively, two cuts may be performed even when the initial imbalance amount is large. Specifically, when the initial imbalance amount is large, the core cutting amount may be increased, but in order to ensure the core magnetic circuit and mechanical strength, it is necessary to regulate the cutting depth of the recess. There is. For this reason, instead of increasing the cutting amount of the core at one time, the cutting position may be dispersed and the core may be cut in two steps. Thus, when the core is cut twice, there are four steps in total at the cutting boundaries in the two concave portions (cutting portions).
　この場合、図７および図８に示すように、コア１１の切削により形成された凹部１１１Ｘの各段差は、９０°であり、鋭利なものとなっている。このため、コア１１の切削により形成された凹部１１１Ｘによって、回転ファンの回転時に風切り音が発生することが分かった。 In this case, as shown in FIGS. 7 and 8, each step of the recess 111X formed by cutting the core 11 is 90 °, which is sharp. For this reason, it was found that a wind noise was generated when the rotary fan was rotated due to the recess 111X formed by cutting the core 11.
　つまり、回転ファン３によって吸引された空気がエアガイド４の通風路を経てフレーム６内に配置された回転子１０と固定子２０との隙間を通過する際に、その空気が、回転子１０（コア１１）の回転によって、コア１１の切削により形成された凹部１１１Ｘの２つの段差に衝突する。これが原因となって、風切り音が発生することが分かった。 That is, when the air sucked by the rotary fan 3 passes through the air passage of the air guide 4 and passes through the gap between the rotor 10 and the stator 20 disposed in the frame 6, the air By rotation of the core 11), it collides with two steps of the recessed part 111X formed by cutting of the core 11. As shown in FIG. It was found that this caused wind noise.
　本発明者は、コア１１の切削により形成した凹部１１１Ｘによる風切り音が、回転ファンの回転数の偶数倍の周波数の音の発生要因であることを突き止めた。 The inventor has found that the wind noise due to the recess 111X formed by the cutting of the core 11 is the generation factor of the sound having a frequency that is an even multiple of the rotational speed of the rotating fan.
　つまり、コア１１を切削して凹部１１１Ｘを形成すると、１つの凹部１１１Ｘには２つの段差が形成される。このため、１つの凹部１１１Ｘがコア１１に形成されている場合は、回転数の２倍の周波数の音が発生する。また、２つの凹部１１１Ｘがコア１１に形成されている場合は、２つの凹部１１１Ｘによって合計４つの段差が形成される。このため、回転数の４倍の周波数の音が発生する。 That is, when the core 11 is cut to form the recess 111X, two steps are formed in one recess 111X. For this reason, when one concave portion 111X is formed in the core 11, a sound having a frequency twice as high as the rotational speed is generated. Moreover, when two recessed parts 111X are formed in the core 11, a total of four level | step differences are formed by two recessed parts 111X. For this reason, a sound having a frequency four times the rotational speed is generated.
　特に、回転ファンの回転数が４０，０００ｒｐｍ（＝約６６７Ｈｚ）程度の高速になると、回転数の偶数倍の周波数は、１，０００Ｈｚ～３，０００Ｈｚ程度の可聴域の周波数となる。つまり、回転ファンの回転数の偶数倍の周波数は、人の聴感の感度が高い周波数帯になる。したがって、耳障りな音となり易い。 In particular, when the rotational speed of the rotating fan is as high as about 40,000 rpm (= about 667 Hz), the frequency of the even multiple of the rotational speed is a frequency in the audible range of about 1,000 Hz to 3,000 Hz. That is, the frequency that is an even multiple of the rotational speed of the rotating fan is a frequency band where the sensitivity of human hearing is high. Therefore, it is easy to become an unpleasant sound.
　このように、回転ファンの回転数の偶数倍の周波数の音が凹部１１１Ｘによる風切り音の要因であることは、これまで知られておらず、本発明者が突き止めたものである。 As described above, it has not been known until now that the sound with a frequency that is an even multiple of the rotational speed of the rotary fan is the cause of the wind noise due to the recess 111X, and the present inventor has identified.
　本開示は、このような知見に基づいてなされたものである。本発明者は、鋭意検討した結果、回転子のコアを切削することにより形成された凹部について、凹部における切削境界の段差の角をなくすことで、凹部による風切り音を抑制できるという着想を得た。 The present disclosure is made based on such findings. As a result of intensive investigations, the inventor of the present invention has obtained an idea that the wind noise caused by the recess can be suppressed by eliminating the corner of the step of the cutting boundary in the recess in the recess formed by cutting the core of the rotor. .
　具体的には、図５から図７に示すように、本実施の形態における電動機２において、第１凹部１１１は、底面１１１ａと、回転子１０の回転方向Ｒに対面する一対の側面１１１ｂとを有する。シャフト３０の軸心Ｃを法線とする断面において、一対の側面１１１ｂのうち少なくとも一方は、コア１１の外面と一方の側面１１１ｂとが交差する第１交点１５ａと、底面１１１ａと一方の側面１１１ｂとが交差する第２交点１６ａとを有する。ここで、第１交点１５ａと第２交点１６ａとを通る直線をＲｂとする。直線Ｒｂと底面１１１ａとがなす角度θ１は、鈍角である。 Specifically, as shown in FIGS. 5 to 7, in the electric motor 2 according to the present embodiment, the first recess 111 includes a bottom surface 111 a and a pair of side surfaces 111 b facing in the rotational direction R of the rotor 10. Have. In a cross section in which the axial center C of the shaft 30 is a normal, at least one of the pair of side surfaces 111b is a first intersection point 15a where the outer surface of the core 11 intersects one side surface 111b, the bottom surface 111a and one side surface 111b And a second intersection point 16a intersecting with each other. Here, a straight line passing the first intersection point 15a and the second intersection point 16a is taken as Rb. An angle θ1 formed by the straight line Rb and the bottom surface 111a is an obtuse angle.
　他の言い方をすれば、シャフト３０の軸心Ｃを法線とする断面において、第２交点１６ａは、第１交点１５ａと軸心Ｃとを通る直線Ｒａよりも底面１１１ａ側に位置する。 In other words, in a cross section having the axis C of the shaft 30 as a normal, the second intersection 16a is located closer to the bottom surface 111a than a straight line Ra passing through the first intersection 15a and the axis C.
　この構成により、回転ファン３によって吸引された空気が回転子１０と固定子２０との間を通過する際に、第１凹部１１１の段差での衝突を軽減することができ、第１凹部１１１による風切り音を低減することができる。これにより、回転子１０の回転によって発生する回転数の偶数倍の周波数の音を抑制することができる。したがって、重量バランスの偏りによって生じる振動を抑制しつつ風切り音を抑制できる。よって、低騒音の電動機２および電動送風機１を実現することができる。しかも、回転子１０による風損を抑制することができるので、電動機２の効率を向上させることもできる。つまり、電動送風機１の振動および騒音の抑制と電動機２の性能の改善との両立を図ることができる。 With this configuration, when air sucked by the rotary fan 3 passes between the rotor 10 and the stator 20, the collision at the step of the first recess 111 can be reduced, and the first recess 111 causes the collision. Wind noise can be reduced. Thereby, the sound of the frequency of the even multiple of the number of rotations generated by rotation of rotor 10 can be controlled. Therefore, the wind noise can be suppressed while suppressing the vibration generated by the deviation of the weight balance. Therefore, the low noise motor 2 and the electric blower 1 can be realized. And since the windage loss by the rotor 10 can be suppressed, the efficiency of the electric motor 2 can also be improved. That is, it is possible to achieve both suppression of vibration and noise of the electric blower 1 and improvement of the performance of the motor 2.
　また、本実施の形態において、第１凹部１１１は、コア１１の複数のティース１１ａにわたって設けられており、第１凹部１１１の側面１１１ｂは、テーパ面となっている。 Further, in the present embodiment, the first recess 111 is provided across the plurality of teeth 11 a of the core 11, and the side surface 111 b of the first recess 111 is a tapered surface.
　この構成により、第１凹部１１１における空気の急激な衝突をより軽減できる。よって、回転ファンの回転数の偶数倍の周波数の音を一層抑制することができる。 This configuration can further reduce sudden collision of air in the first recess 111. Therefore, the sound of the frequency of the even multiple of the rotation speed of the rotary fan can be further suppressed.
　図９は、回転子１０のコア１１を切削して凹部を形成するときの実施の形態に係る切削方法を説明するための図である。第１凹部１１１は、図９に示すように、鼓状の切削刃２００を用いて形成することができる。この場合、本実施の形態における切削刃２００は、図７に示す従来の切削刃２００Ｘにおいて、両端部に平坦部２０１が形成された形状となっている。つまり、切削刃２００の両端は、実質的に平行な円筒状となっている。 FIG. 9 is a view for explaining the cutting method according to the embodiment when the core 11 of the rotor 10 is cut to form a recess. The first recess 111 can be formed using a drum-shaped cutting blade 200, as shown in FIG. In this case, the cutting blade 200 in the present embodiment has a shape in which flat portions 201 are formed at both ends of the conventional cutting blade 200X shown in FIG. That is, both ends of the cutting blade 200 are in a substantially parallel cylindrical shape.
　このように構成された鼓状の切削刃２００を用いてコア１１（ティース１１ａ）を切削して第１凹部１１１を形成することで、切削した後の切削境界付近は、徐々に切削深さが浅くなっていく。このため、切削境界部に急激な段差が生じない。本実施の形態では、切削刃２００を用いることで、第１凹部１１１の側面１１１ｂを、例えばテーパ角θ２が４５°のテーパ面（傾斜面）にすることができる。つまり、直線Ｒｂと底面１１１ａとがなす角度θ１は、１３５°となる。図９に示す切削刃２００を用いて第１凹部１１１を形成することで、第１凹部１１１の切削境界の段差に、切削刃２００の摩耗によるバリが発生することも抑制できる。 By forming the first recess 111 by cutting the core 11 (the teeth 11a) using the drum-shaped cutting blade 200 configured in this manner, the cutting depth gradually increases in the vicinity of the cutting boundary after cutting. It gets shallow. For this reason, a sharp level difference does not occur at the cutting boundary. In the present embodiment, by using the cutting blade 200, the side surface 111b of the first recess 111 can be made into a tapered surface (inclined surface) having a taper angle θ2 of 45 °, for example. That is, the angle θ1 formed by the straight line Rb and the bottom surface 111a is 135 °. By forming the first recess 111 using the cutting blade 200 shown in FIG. 9, it is possible to suppress the generation of burrs due to the wear of the cutting blade 200 in the step of the cutting boundary of the first recess 111.
　ここで、本実施の形態における電動送風機１と従来の電動送風機との騒音を測定した実験結果について、図１０および図１１を用いて説明する。図１０は、従来の電動送風機における振動数と音圧との関係を示す図である。図１１は、実施の形態に係る電動送風機１における振動数と音圧との関係を示す図である。 Here, the experimental result which measured the noise of the electric blower 1 in this Embodiment and the conventional electric blower is demonstrated using FIG. 10 and FIG. FIG. 10 is a diagram showing the relationship between the frequency and the sound pressure in the conventional electric fan. FIG. 11 is a diagram showing the relationship between the vibration frequency and the sound pressure in the electric blower 1 according to the embodiment.
　図１０における従来の電動送風機では、図７に示す従来の切削刃２００Ｘによってコア１１を切削して凹部１１１Ｘを形成した回転子１０を有する電動機を用いている。図１１における本実施の形態に係る電動送風機１では、図９に示す切削刃２００によってコア１１を切削して第１凹部１１１を形成した回転子１０を有する電動機２を用いている。なお、図１０における従来の電動送風機と、図１１における本実施の形態に係る電動送風機１とは、凹部１１１Ｘおよび第１凹部１１１のみが異なり、それ以外の構成は同じである。また、本実験において、回転ファン３の回転数Ｎは、Ｎ＝６５３Ｈｚとしている。 The conventional electric blower in FIG. 10 uses a motor having a rotor 10 in which the core 11 is cut by the conventional cutting blade 200X shown in FIG. 7 to form a recess 111X. The electric blower 1 according to the present embodiment in FIG. 11 uses the motor 2 having the rotor 10 in which the first recess 111 is formed by cutting the core 11 with the cutting blade 200 shown in FIG. The conventional electric blower in FIG. 10 and the electric blower 1 according to the present embodiment in FIG. 11 are different only in the recess 111X and the first recess 111, and the other configurations are the same. Further, in the present experiment, the rotational speed N of the rotary fan 3 is N = 653 Hz.
　図１０および図１１に示すように、回転数の２倍（２Ｎ）の周波数である１３０６Ｈｚにおいては、従来の電動送風機の音圧が７６．８ｄＢ（図１０）であるのに対して、本実施の形態に係る電動送風機１の音圧が７０．５ｄＢ（図１１）となっている。このように、本実施の形態に係る電動送風機１によれば、回転数の２倍の周波数の音圧を抑制できることが分かる。 As shown in FIGS. 10 and 11, the sound pressure of the conventional electric blower is 76.8 dB (FIG. 10) at 1306 Hz, which is a frequency twice (2 N) of the rotational speed. The sound pressure of the electric blower 1 according to the embodiment is 70.5 dB (FIG. 11). Thus, according to the electric blower 1 which concerns on this Embodiment, it turns out that the sound pressure of the frequency twice the rotation speed can be suppressed.
　同様に、回転数の４倍（４Ｎ）の周波数である２６０９Ｈｚにおいては、従来の電動送風機の音圧が７４．６ｄＢ（図１０）であるのに対して、本実施の形態に係る電動送風機１の音圧が７１．９ｄＢ（図１１）となっている。このように、本実施の形態に係る電動送風機１によれば、回転数の４倍の周波数の音圧も抑制できることが分かる。 Similarly, at 2609 Hz, which is a frequency four times the rotational speed (4 N), the sound pressure of the conventional electric blower is 74.6 dB (FIG. 10), whereas the electric blower 1 according to the present embodiment Sound pressure of 71.9 dB (FIG. 11). Thus, according to the electric blower 1 which concerns on this Embodiment, it turns out that the sound pressure of the frequency of 4 times of rotation speed can also be suppressed.
　なお、図１０および図１１に示す特性図は、デジタル表示された計測器の値のため、真値を示すものではなく、誤差を有していることもある。 Note that the characteristic diagrams shown in FIGS. 10 and 11 do not show true values because they are values of the digitally displayed measuring instrument, and may have errors.
　これに対して、回転数の７倍（７Ｎ）の周波数である４５６５Ｈｚにおいては、従来の電動送風機の音圧が７９．５ｄＢ（図１０）であるのに対して、本実施の形態に係る電動送風機１の音圧が８０．０ｄＢ（図１１）となっている。つまり、回転数の７倍の周波数については、従来の電動送風機と本実施の形態に係る電動送風機１とでは音圧が同程度であり、本実施の形態に係る電動送風機１における第１凹部１１１による音圧の抑制効果が見られない。なお、回転数の７倍の周波数で音圧のピークが現れるのは、本実験で用いた回転ファン３の翼数が７枚であったことが要因である。 On the other hand, at 4565 Hz, which is a frequency seven times the rotational speed (7 N), the sound pressure of the conventional electric blower is 79.5 dB (FIG. 10), whereas the electric power according to the present embodiment. The sound pressure of the blower 1 is 80.0 dB (FIG. 11). In other words, the sound pressure of the conventional electric blower and the electric blower 1 according to the present embodiment are about the same in sound pressure as to the frequency seven times the rotational speed, and the first recess 111 in the electric blower 1 according to the present embodiment. There is no sound pressure suppression effect due to The sound pressure peak appears at a frequency seven times the rotational speed because the number of blades of the rotary fan 3 used in this experiment is seven.
　本実験によれば、回転数の１倍（１Ｎ）の周波数である６５３Ｈｚにおいても、音圧抑制の効果が現れている。具体的には、回転数の１倍の周波数における音圧は、電動機の振動音に起因するものである。回転数の１倍の周波数においては、従来の電動送風機の音圧が７６．８ｄＢで、本実施の形態に係る電動送風機１の音圧が７３．５ｄＢとなっている。 According to this experiment, the sound pressure suppression effect appears even at 653 Hz, which is a frequency that is one time the rotational speed (1N). Specifically, the sound pressure at a frequency that is one time the rotational speed is due to the vibration noise of the motor. The sound pressure of the conventional electric blower is 76.8 dB and the sound pressure of the electric blower 1 according to the present embodiment is 73.5 dB at a frequency that is one time the rotational speed.
　このように、本実験によれば、シャフト３０の軸心Ｃを法線とする断面において、第１交点１５ａと第２交点１６ａとを通る直線Ｒｂと、底面１１１ａとのなす角度θ１が鈍角である、第１凹部１１１を形成することによって、人の聴感の感度が高い周波数帯である１，０００Ｈｚから３，０００Ｈｚ程度の可聴域の周波数において、回転ファンの回転数の偶数倍の周波数の音を抑制できることが分かる。 As described above, according to the present experiment, in a cross section having the axial center C of the shaft 30 as a normal, a straight line Rb passing through the first intersection point 15a and the second intersection point 16a and an angle θ1 formed by the bottom surface 111a are obtuse angles By forming the first recess 111, sound at an even multiple of the rotational speed of the rotating fan at a frequency in the audible range of about 1,000 Hz to 3,000 Hz, which is a frequency band in which human hearing sensitivity is high Can be suppressed.
　本実験では、従来の電動機の効率が５２．２％であり、本実施の形態における電動機２の効率が５２．５％であった。つまり、シャフト３０の軸心Ｃを法線とする断面において、第１交点１５ａと第２交点１６ａとを通る直線Ｒｂと、底面１１１ａとのなす角度θ１が鈍角である、第１凹部１１１を形成することによって、電動機の効率が向上することも分かった。 In this experiment, the efficiency of the conventional motor was 52.2%, and the efficiency of the motor 2 in the present embodiment was 52.5%. That is, in a cross section having the axis C of the shaft 30 as a normal, the first recess 111 is formed such that the angle θ1 between the straight line Rb passing the first intersection 15a and the second intersection 16a and the bottom surface 111a is an obtuse angle It was also found that by doing this, the efficiency of the motor was improved.
　なお、本実施の形態では、第１凹部１１１において、直線Ｒｂと底面１１１ａとのなす角度θ１を鈍角である１３５°としたが、これに限らない。図１２は、実施の形態の一例に係る電動機２が備える回転子１０に形成された第１凹部１１１の構成を示す断面図である。図１３は、実施の形態の他の例に係る電動機２が備える回転子１０に形成された第１凹部１１１の構成を示す断面図である。例えば、図１２に示すように、第１凹部１１１において、直線Ｒｂと底面１１１ａとのなす角度θ１は、鈍角であれば１３５°未満であってもよい。あるいは、図１３に示すように、第１凹部１１１において、直線Ｒｂと底面１１１ａとのなす角度θ１は、１３５°を越えていてもよい。 In the present embodiment, in the first concave portion 111, the angle θ1 formed by the straight line Rb and the bottom surface 111a is 135 °, which is an obtuse angle, but the present invention is not limited to this. FIG. 12 is a cross-sectional view showing the configuration of the first recess 111 formed in the rotor 10 of the motor 2 according to an example of the embodiment. FIG. 13 is a cross-sectional view showing the configuration of the first recess 111 formed in the rotor 10 of the motor 2 according to another example of the embodiment. For example, as shown in FIG. 12, in the first concave portion 111, the angle θ1 between the straight line Rb and the bottom surface 111a may be less than 135 ° as long as it is an obtuse angle. Alternatively, as shown in FIG. 13, in the first recess 111, an angle θ1 formed by the straight line Rb and the bottom surface 111a may exceed 135 °.
　言い換えれば、本実施の形態では、第１凹部１１１の側面１１１ｂのテーパ角θ２を鋭角である４５°としたが、これに限らない。例えば、図１２に示すように、第１凹部１１１の側面１１１ｂのテーパ角θ２は４５°を超えていてもよいし、図１３に示すように、第１凹部１１１の側面１１１ｂのテーパ角θ２は４５°未満であってもよい。 In other words, in the present embodiment, the taper angle θ2 of the side surface 111b of the first recess 111 is 45 °, which is an acute angle, but the present invention is not limited to this. For example, as shown in FIG. 12, the taper angle θ2 of the side surface 111b of the first recess 111 may exceed 45 °, and as shown in FIG. 13, the taper angle θ2 of the side surface 111b of the first recess 111 is It may be less than 45 °.
　以上のように、本実施の形態の電動機２は、回転子１０と、回転子１０に固定されるとともに、回転子１０の軸心Ｃ方向に延伸したシャフト３０と、を備える。回転子１０は、複数のティース１１ａが形成されたコア１１と、隣り合うティース１１ａの間に配置されたコイル１２とを有する。コア１１は、コア１１の外面の一部を窪ませた第１凹部１１１を有する。第１凹部１１１は、底面１１１ａと、回転子１０の回転方向に対面する一対の側面１１１ｂとを有する。軸心Ｃを法線とする断面において、一対の側面１１１ｂのうち少なくとも一方は、コア１１の外面と交差する第１交点１５ａと、底面１１１ａと交差する第２交点１６ａとを有し、第１交点１５ａと第２交点１６ａとを通る直線Ｒｂと底面１１１ａとのなす角度は鈍角である。 As described above, the motor 2 of the present embodiment includes the rotor 10 and the shaft 30 fixed to the rotor 10 and extended in the axial center C direction of the rotor 10. The rotor 10 has a core 11 in which a plurality of teeth 11 a are formed, and a coil 12 disposed between adjacent teeth 11 a. The core 11 has a first recess 111 in which a part of the outer surface of the core 11 is recessed. The first recess 111 has a bottom surface 111 a and a pair of side surfaces 111 b facing in the rotational direction of the rotor 10. In a cross section normal to the axial center C, at least one of the pair of side surfaces 111b has a first intersection point 15a intersecting with the outer surface of the core 11 and a second intersection point 16a intersecting with the bottom surface 111a. The angle between a straight line Rb passing through the intersection point 15a and the second intersection point 16a and the bottom surface 111a is an obtuse angle.
　これにより、重量バランスの偏りによって生じる振動を抑制しつつ、風切り音を抑制できる。したがって、低騒音の電動機２を実現することができる。 Thereby, the wind noise can be suppressed while suppressing the vibration caused by the deviation of the weight balance. Therefore, the low noise motor 2 can be realized.
　また、第１凹部１１１は、複数のティース１１ａにわたって設けられていてもよい。 Moreover, the 1st recessed part 111 may be provided over several teeth 11a.
　これにより、第１凹部１１１における空気の急激な衝突をより軽減できる。よって、回転ファンの回転数の偶数倍の周波数の音を一層抑制することができる。 Thereby, the sudden collision of air in the first recess 111 can be further reduced. Therefore, the sound of the frequency of the even multiple of the rotation speed of the rotary fan can be further suppressed.
　また、第１凹部１１１は、シャフト３０の長手方向のコア１１の端部に設けられていてもよい。 The first recess 111 may be provided at the end of the core 11 in the longitudinal direction of the shaft 30.
　また、軸心Ｃを法線とする断面において、一対の側面１１１ｂの少なくとも一方は、回転子１０の回転方向に沿って深さが変化する部位を含んでもよい。 In a cross section normal to the axial center C, at least one of the pair of side surfaces 111 b may include a portion whose depth changes along the rotation direction of the rotor 10.
　また、部位は、テーパ面であってもよい。 Also, the portion may be a tapered surface.
　また、部位は、湾曲面であってもよい。 Also, the portion may be a curved surface.
　また、部位は、一対の側面１１１ｂの少なくとも一方であってもよい。 Further, the portion may be at least one of the pair of side surfaces 111b.
　また、軸心Ｃを法線とする断面において、第１凹部１１１は、線対称形状であってもよい。 Moreover, in the cross section which makes the axial center C a normal, the 1st recessed part 111 may be line symmetrical.
　また、コア１１は、コア１１の外面の一部を窪ませた第２凹部１１２を有してもよい。 The core 11 may also have a second recess 112 in which a part of the outer surface of the core 11 is recessed.
　また、軸心Ｃを法線とする断面において、第２凹部１１２の断面形状は、Ｖ字であってもよい。 Moreover, in the cross section which makes the axial center C a normal, the cross-sectional shape of the 2nd recessed part 112 may be V shape.
　また、軸心Ｃを法線とする断面において、第２凹部１１２の断面形状は、Ｕ字であってもよい。 Moreover, in the cross section which makes the axial center C a normal, the cross-sectional shape of the 2nd recessed part 112 may be U-shape.
　また、本実施の形態の電動送風機１は、電動機２と、電動機２が備えるシャフト３０に取り付けられた回転ファン３と、を備える。 Further, the electric blower 1 of the present embodiment includes the electric motor 2 and the rotary fan 3 attached to the shaft 30 provided in the electric motor 2.
　これにより、重量バランスの偏りによって生じる振動を抑制しつつ、風切り音を抑制できる。したがって、低騒音の電動送風機１を実現することができる。 Thereby, the wind noise can be suppressed while suppressing the vibration caused by the deviation of the weight balance. Therefore, a low noise electric blower 1 can be realized.
　また、このように構成される電動送風機１は、例えば家庭用の電気掃除機に用いられる。以下、電動送風機１が用いられる電気掃除機８について、図１４を用いて説明する。図１４は、実施の形態に係る電動送風機１を用いた電気掃除機８の一例を示す模式図である。 Moreover, the electric blower 1 comprised in this way is used for a domestic vacuum cleaner, for example. Hereinafter, the vacuum cleaner 8 in which the electric blower 1 is used is demonstrated using FIG. FIG. 14 is a schematic view showing an example of a vacuum cleaner 8 using the electric blower 1 according to the embodiment.
　図１４に示すように、電気掃除機８は、電動機２を用いた電動送風機１と、電動送風機１（電動機２）を制御する制御部８ａとを備えている。電気掃除機８は、電動送風機１によって吸引して清掃する。制御部８ａは、電動送風機１（電動機２）を制御する。例えば、制御部８ａは、電動送風機１による吸引を停止したり、開始したり、吸引量を調整したりする。 As shown in FIG. 14, the vacuum cleaner 8 is provided with the electric blower 1 using the electric motor 2, and the control part 8a which controls the electric blower 1 (electric motor 2). The vacuum cleaner 8 is sucked by the electric blower 1 to clean it. The controller 8a controls the electric blower 1 (electric motor 2). For example, the control unit 8a stops suctioning by the electric blower 1, starts it, or adjusts the suction amount.
　このように、本実施の形態における電気掃除機８は、電動送風機１を用いているので、低騒音の電気掃除機を実現できる。 As described above, since the electric vacuum cleaner 8 in the present embodiment uses the electric blower 1, a low noise electric vacuum cleaner can be realized.
　図１５に示すように、電動送風機１は、手を風で乾かすエアタオル９に用いてもよい。図１５は、実施の形態に係る電動送風機１を用いたエアタオル９の一例を示す模式図である。 As shown in FIG. 15, the electric blower 1 may be used as an air towel 9 for drying hands. FIG. 15 is a schematic view showing an example of the air towel 9 using the electric blower 1 according to the embodiment.
　図１５に示すように、エアタオル９は、電動機２を用いた電動送風機１と、電動送風機１（電動機２）を制御する制御部９ａとを備えている。エアタオル９では、電動送風機１によって、温風又は冷風を送風する。制御部９ａは、電動送風機１（電動機２）を制御する。例えば、制御部９ａは、電動送風機１による送風を停止したり、開始したり、送風量を調整したりする。 As shown in FIG. 15, the air towel 9 includes an electric blower 1 using the electric motor 2 and a control unit 9a that controls the electric blower 1 (electric motor 2). In the air towel 9, hot air or cold air is blown by the electric blower 1. The controller 9a controls the electric blower 1 (electric motor 2). For example, the control unit 9a stops or starts air blowing by the electric blower 1, or adjusts the air blowing amount.
　このように、本実施の形態におけるエアタオル９は、電動送風機１を用いているので、低騒音のエアタオルを実現できる。 Thus, since the air towel 9 in the present embodiment uses the electric blower 1, a low noise air towel can be realized.
　（変形例）
　以上、本開示に係る電動機、電動送風機、電気掃除機およびエアタオル等について、実施の形態に基づいて説明したが、本開示は、上記実施の形態に限定されるものではない。 (Modification)
As mentioned above, although the electric motor concerning this indication, an electric blower, a vacuum cleaner, an air towel, etc. were explained based on an embodiment, this indication is not limited to the above-mentioned embodiment.
　例えば、本開示の特徴である、第１交点と第２交点の関係を分かり易く説明するために、上記実施の形態では、全体がフラット面である傾斜面を用いて説明を行った。しかし、第１凹部の側面は、全体がフラット面である傾斜面に限らない。 For example, in order to explain the relationship between the first intersection point and the second intersection point, which is a feature of the present disclosure, in an easily understandable manner, the above embodiment has been described using an inclined surface which is entirely flat. However, the side surface of the first recess is not limited to the inclined surface which is entirely flat.
　具体的には、図１６に示すように、側面１１１ｂ全体が凹状の湾曲面である第１凹部１１１Ａであってもよいし、図１７に示すように、側面１１１ｂ全体が凸状の湾曲面である第１凹部１１１Ｂであってもよい。図１６は、変形例に係る電動機２が備える回転子１０に形成された第１凹部１１１Ａの構成を示す断面図である。図１７は、変形例に係る電動機２が備える回転子１０に形成された第１凹部１１１Ｂの構成を示す断面図である。 Specifically, as shown in FIG. 16, the entire first side 111b may be a first concave portion 111A that is a concave curved surface, or as shown in FIG. 17, the entire side 111b is a convex curved surface. It may be a certain first recess 111B. FIG. 16 is a cross-sectional view showing the configuration of the first recess 111A formed in the rotor 10 of the motor 2 according to the modification. FIG. 17 is a cross-sectional view showing the configuration of the first recess 111B formed in the rotor 10 of the motor 2 according to the modification.
　また、図１８および図１９に示すように、凹状の湾曲面および凸状の湾曲面の両方を含む側面１１１ｂであってもよい。図１８は、変形例に係る電動機２が備える回転子１０に形成された第１凹部１１１Ｃの構成を示す断面図である。図１９は、変形例に係る電動機２が備える回転子１０に形成された第１凹部１１１Ｄの構成を示す断面図である。具体的には、図１８に示される第１凹部１１１Ｃの側面１１１ｂは、コア１１の外面側が凸状の湾曲面で、底面１１１ａ側が凹状の湾曲面となっている。図１９に示される第１凹部１１１Ｄの側面１１１ｂは、コア１１の外面側が凹状の湾曲面で、底面１１１ａ側が凸状の湾曲面となっている。なお、図１８および図１９に示される第１凹部１１１Ｃおよび１１１Ｄにおいて、側面１１１ｂにさらにフラット面が含まれていてもよい。 In addition, as shown in FIGS. 18 and 19, the side surface 111 b may include both a concave curved surface and a convex curved surface. FIG. 18 is a cross-sectional view showing the configuration of a first recess 111C formed in the rotor 10 of the motor 2 according to the modification. FIG. 19 is a cross-sectional view showing the configuration of the first recess 111D formed in the rotor 10 of the motor 2 according to the modification. Specifically, the side surface 111b of the first recess 111C shown in FIG. 18 is a convex curved surface on the outer surface side of the core 11, and a concave curved surface on the bottom surface 111a side. In the side surface 111b of the first recess 111D shown in FIG. 19, the outer surface side of the core 11 is a concave curved surface, and the bottom surface 111a side is a convex curved surface. In the first recesses 111C and 111D shown in FIGS. 18 and 19, the side surface 111b may further include a flat surface.
　また、図２０および図２１に示される第１凹部１１１Ｅおよび１１１Ｆのように、切削境界の段差の角が面取りされた形状であってもよい。図２０は、変形例に係る電動機２が備える回転子１０に形成された第１凹部１１１Ｅの構成を示す断面図である。図２１は、変形例に係る電動機２が備える回転子１０に形成された第１凹部１１１Ｆの構成を示す断面図である。つまり、側面１１１ｂとコア１１の外面との境界部の稜線が面取りされていてもよい。具体的には、図２０に示される第１凹部１１１Ｅでは、切削境界の段差の角がＣ面１１１ｃとなるように面取りされており、第１凹部１１１Ｅの側面１１１ｂはＣ面１１１ｃを含んでいる。図２１に示される第１凹部１１１Ｆでは、切削境界の段差の角がＲ面１１１ｄとなるように面取りされており、第１凹部１１１Ｆの側面１１１ｂはＲ面１１１ｄを含んでいる。 Further, as in the first recesses 111E and 111F shown in FIGS. 20 and 21, the corner of the step of the cutting boundary may be chamfered. FIG. 20 is a cross-sectional view showing the configuration of a first recess 111E formed in the rotor 10 of the motor 2 according to the modification. FIG. 21 is a cross-sectional view showing the configuration of the first recess 111F formed in the rotor 10 of the motor 2 according to the modification. That is, the ridgeline of the boundary between the side surface 111 b and the outer surface of the core 11 may be chamfered. Specifically, in the first recess 111E shown in FIG. 20, the corner of the step of the cutting boundary is chamfered so as to be the C surface 111c, and the side surface 111b of the first recess 111E includes the C surface 111c. . In the first recess 111F shown in FIG. 21, the corner of the step of the cutting boundary is chamfered so as to be the R surface 111d, and the side surface 111b of the first recess 111F includes the R surface 111d.
　図２０および図２１に示す平面は、シャフト３０の軸心Ｃを法線とする断面である。ここで、Ｃ面１１１ｃとは、シャフト３０の軸心Ｃを法線とする断面において、コア１１の外面と側面１１１ｂとの間に位置する面である。例えば、Ｃ面１１１ｃは、第１凹部１１１Ｅを形成した後、コア１１の外面と側面１１１ｂとの間に位置する角部を削るなどして形成できる。あるいは、Ｃ面１１１ｃは、上述した切削刃２００の形状を調整することで形成できる。つまり、一対の側面１１１ｂの各々とコア１１の外面との境界部には、角がなくてもよい。 The plane shown in FIG. 20 and FIG. 21 is a cross section having an axis C of the shaft 30 as a normal. Here, the C surface 111 c is a surface located between the outer surface of the core 11 and the side surface 111 b in a cross section with the axial center C of the shaft 30 as a normal. For example, the C surface 111c can be formed by, for example, scraping a corner located between the outer surface of the core 11 and the side surface 111b after forming the first recess 111E. Alternatively, the C surface 111 c can be formed by adjusting the shape of the cutting blade 200 described above. That is, the boundary between each of the pair of side surfaces 111 b and the outer surface of the core 11 may have no corner.
　同様に、Ｒ面１１１ｄとは、シャフト３０の軸心Ｃを法線とする断面において、コア１１の外面と側面１１１ｂとの間に位置する曲面である。例えば、Ｒ面１１１ｄは、第１凹部１１１Ｆを形成した後、コア１１の外面と側面１１１ｂとの間に位置する角部を削るなどして形成できる。あるいは、Ｃ面１１１ｃは、上述した切削刃２００の形状を調整することで形成できる。 Similarly, the R surface 111 d is a curved surface located between the outer surface of the core 11 and the side surface 111 b in a cross section having the axial center C of the shaft 30 as a normal. For example, after forming the first recess 111F, the R surface 111d can be formed by, for example, scraping a corner portion located between the outer surface of the core 11 and the side surface 111b. Alternatively, the C surface 111 c can be formed by adjusting the shape of the cutting blade 200 described above.
　図２２および図２３に示される第１凹部１１１Ｇおよび１１１Ｈのように、切削境界の段差の角を面取りして角をなくしているだけではなく、段差の根元（底面１１１ａと側面１１１ｂとの境界）の角もなくしてもよい。図２２は、変形例に係る電動機２が備える回転子１０に形成された第１凹部１１１Ｇの構成を示す断面図である。図２３は、変形例に係る電動機２が備える回転子１０に形成された第１凹部１１１Ｈの構成を示す断面図である。具体的には、図２２に示される第１凹部１１１Ｇでは、切削境界の段差の角がＣ面１１１ｃとなるように面取りされているとともに、段差の根元部分が傾斜面となっており、第１凹部１１１Ｇの側面１１１ｂはＣ面１１１ｃと傾斜面とを含んでいる。図２３に示される第１凹部１１１Ｈでは、切削境界の段差の角がＲ面１１１ｄとなるように面取りされているとともに、段差の根元部分が湾曲面となっており、第１凹部１１１Ｈの側面１１１ｂはＲ面１１１ｄと湾曲面とを含んでいる。 As in the first recesses 111G and 111H shown in FIGS. 22 and 23, not only are the corners of the step of the cutting boundary chamfered to eliminate the corner, but also the root of the step (boundary between the bottom surface 111a and the side surface 111b) You may not have the corner of FIG. 22 is a cross-sectional view showing the configuration of the first recess 111G formed in the rotor 10 of the motor 2 according to the modification. FIG. 23 is a cross-sectional view showing the configuration of the first recess 111H formed in the rotor 10 of the motor 2 according to the modification. Specifically, in the first recess 111G shown in FIG. 22, the corner of the step of the cutting boundary is chamfered so as to be the C surface 111c, and the root portion of the step is an inclined surface, The side surface 111b of the recess 111G includes a C surface 111c and an inclined surface. In the first recess 111H shown in FIG. 23, the corner of the step of the cutting boundary is chamfered to be the R surface 111d, and the root portion of the step is a curved surface, and the side surface 111b of the first recess 111H Includes the R surface 111 d and the curved surface.
　また、実施の形態では、第１凹部１１１において、一対の側面１１１ｂの各々とコア１１の外面との２つの境界部の各々に角がないようにしたが、これに限らない。つまり、第１凹部１１１は、一対の側面１１１ｂの少なくとも一方とコア１１の外面との交点である第１交点１５ａと、側面１１１ｂと底面１１１ａとの交点である第２交点１６ａとがつぎの位置にあればよい。すなわち、第１交点１５ａと第２交点１６ａとを通る直線をＲｂとする。このとき、直線Ｒｂと底面１１１ａとがなす角度θ１は、鈍角であるように構成されていればよい。 In the embodiment, in the first recess 111, each of the two boundaries between each of the pair of side surfaces 111b and the outer surface of the core 11 has no corner, but the present invention is not limited to this. That is, in the first concave portion 111, the first intersection point 15a, which is the intersection point of at least one of the pair of side surfaces 111b and the outer surface of the core 11, and the second intersection point 16a, which is the intersection point of the side surface 111b and the bottom surface 111a It is good if That is, a straight line passing the first intersection point 15a and the second intersection point 16a is taken as Rb. At this time, the angle θ1 formed by the straight line Rb and the bottom surface 111a may be an obtuse angle.
　他の言い方をすれば、第２交点１６ａは、第１交点１５ａと軸心Ｃとを通る直線Ｒａよりも底面１１１ａ側に位置するように構成されていればよい。例えば、一対の側面１１１ｂの一方の側面１１１ｂがコア１１の外面に対して傾斜する傾斜面であり、一対の側面１１１ｂの他方の側面１１１ｂがコア１１の外面に対して垂直な面であってもよい。 In other words, the second intersection 16a may be configured to be located closer to the bottom surface 111a than a straight line Ra passing through the first intersection 15a and the axial center C. For example, even if one side surface 111b of the pair of side surfaces 111b is an inclined surface inclined to the outer surface of the core 11, and the other side surface 111b of the pair of side surfaces 111b is a surface perpendicular to the outer surface of the core 11. Good.
　その他、実施の形態に対して当業者が思い付く各種変形を施して得られる形態、又は、本開示の趣旨を逸脱しない範囲で実施の形態における構成要素および機能を任意に組み合わせることで実現される形態も、本開示に含まれる。 In addition, an embodiment obtained by applying various modifications to those skilled in the art to the embodiment, or an embodiment realized by arbitrarily combining components and functions in the embodiment without departing from the scope of the present disclosure. Are also included in the present disclosure.
　本開示の技術は、電動機、電動送風機および電気掃除機等の種々の電気機器に利用することができる。本開示の技術は、特に、遠心ファン等の回転ファンを高速で回転する電気掃除機等に搭載される電動送風機等に有用である。 The technology of the present disclosure can be applied to various electric devices such as an electric motor, an electric blower, and a vacuum cleaner. The technique of the present disclosure is particularly useful for an electric blower or the like mounted on a vacuum cleaner or the like that rotates a rotating fan such as a centrifugal fan at a high speed.
　１　電動送風機
　２　電動機
　３　回転ファン
　４　エアガイド
　４ａ　デュフューザ翼
　５　ブラケット
　６　フレーム
　６ａ　排気口
　７　ファンケース
　７ａ　吸気口
　８　電気掃除機
　８ａ　制御部
　９　エアタオル
　９ａ　制御部
　１０　回転子
　１１　コア
　１１ａ　ティース
　１１ｂ　スロット
　１２　コイル
　１３　ウエッジ
　１４　絶縁フィルム
　１５　外周線
　１５ａ　第１交点
　１６　内周線
　１６ａ　第２交点
　２０　固定子
　３０　シャフト
　４０　整流子
　５０　ブラシ
　６０　第１軸受け部
　７０　第２軸受け部
　１１１、１１１Ａ、１１１Ｂ、１１１Ｃ、１１１Ｄ、１１１Ｅ、１１１Ｆ、１１１Ｇ、１１１Ｈ　第１凹部
　１１１ａ、１１１ｘ　底面
　１１１ｂ、１１１ｙ　側面
　１１１ｃ　Ｃ面
　１１１ｄ　Ｒ面
　１１１Ｘ　凹部
　１１２　第２凹部
　２００、２００Ｘ　切削刃
　２０１　平坦部 DESCRIPTION OF SYMBOLS 1 electric blower 2 motor 3 rotation fan 4 air guide 4a diffuser wing 5 bracket 6 frame 6a exhaust port 7 fan case 7a air inlet 8 electric vacuum cleaner 8a control part 9 air towel 9a control part 10 rotor 11 core 11a teeth 11b slot 12 coil 13 wedge 14 insulating film 15 outer peripheral wire 15a first intersection point 16 inner peripheral line 16a second intersection point 20 stator 30 shaft 40 commutator 50 brush 60 first bearing portion 70 second bearing portion 111, 111A, 111B, 111C, 111D, 111E, 111F, 111G, 111H first concave portion 111a, 111x bottom surface 111b, 111y side surface 111c C surface 111d R surface 111d concave portion 112 second concave portion 200, 200X cutting blade 201 flat portion

Claims (16)

  1. 回転子と、
    前記回転子に固定されるとともに、前記回転子の軸心方向に延伸したシャフトと、
    を備える電動機であって、
    前記回転子は、複数のティースが形成されたコアと、隣り合う前記ティースの間に配置されたコイルとを有し、
    前記コアは、前記コアの外面の一部を窪ませた第１凹部を有し、
    前記第１凹部は、底面と、前記回転子の回転方向に対面する一対の側面とを有し、
    前記軸心を法線とする断面において、前記一対の側面のうち少なくとも一方の側面は、前記コアの外面と交差する第１交点と、前記底面と交差する第２交点とを有し、前記第１交点と前記第２交点とを通る直線と前記底面とのなす角度は鈍角である、
    電動機。     With the rotor,
    A shaft fixed to the rotor and extending in an axial direction of the rotor;
    A motor comprising
    The rotor has a core on which a plurality of teeth are formed, and a coil disposed between the adjacent teeth.
    The core has a first recess in which a portion of the outer surface of the core is recessed;
    The first recess has a bottom surface and a pair of side surfaces facing in the rotational direction of the rotor,
    In the cross section normal to the axis, at least one side surface of the pair of side surfaces has a first intersection intersecting the outer surface of the core and a second intersection intersecting the bottom surface; An angle between a straight line passing through one intersection point and the second intersection point and the bottom surface is an obtuse angle,
    Electric motor.
  2. 前記第１凹部は、前記複数のティースにわたって設けられている、請求項１に記載の電動機。 The motor according to claim 1, wherein the first recess is provided across the plurality of teeth.
  3. 前記第１凹部は、前記シャフトの長手方向の前記コアの端部に設けられている、
    請求項１又は２に記載の電動機。     The first recess is provided at an end of the core in the longitudinal direction of the shaft.
    The electric motor according to claim 1 or 2.
  4. 前記軸心を法線とする断面において、前記一対の側面のうち少なくとも一方の側面は、前記回転子の回転方向に沿って深さが変化する部位を含む、
    請求項１～３のいずれか１項に記載の電動機。     In a cross section normal to the axis, at least one side surface of the pair of side surfaces includes a portion whose depth changes along the rotational direction of the rotor.
    The motor according to any one of claims 1 to 3.
  5. 前記部位は、テーパ面である、
    請求項４に記載の電動機。     The portion is a tapered surface,
    The motor according to claim 4.
  6. 前記部位は、湾曲面である、
    請求項４に記載の電動機。     The part is a curved surface,
    The motor according to claim 4.
  7. 前記部位は、前記一対の側面のうち少なくとも一方の側面の全面である、
    請求項４～６のいずれか１項に記載の電動機。     The portion is an entire surface of at least one side surface of the pair of side surfaces,
    The electric motor according to any one of claims 4 to 6.
  8. 前記一対の側面のうち少なくとも一方の側面と前記コアの外面との境界部の稜線は、面取りされている、
    請求項１～３のいずれか１項に記載の電動機。     The ridgeline of the boundary between the at least one side of the pair of sides and the outer surface of the core is chamfered.
    The motor according to any one of claims 1 to 3.
  9. 前記一対の側面の各々の側面と前記コアの外面との境界部には、角がない、
    請求項１～８のいずれか１項に記載の電動機。     There are no corners at the boundary between each side of the pair of sides and the outer surface of the core,
    A motor according to any one of the preceding claims.
  10. 前記軸心を法線とする断面において、前記第１凹部は、線対称形状である、
    請求項９に記載の電動機。     In the cross section normal to the axis, the first recess has a line symmetrical shape.
    The motor according to claim 9.
  11. 前記コアは、前記コアの外面の一部を窪ませた第２凹部を有する、
    請求項１～１０のいずれか１項に記載の電動機。     The core has a second recess in which a portion of the outer surface of the core is recessed,
    The electric motor according to any one of claims 1 to 10.
  12. 前記軸心を法線とする断面において、前記第２凹部の断面形状は、Ｖ字である、
    請求項１１に記載の電動機。     In the cross section in which the axis is normal, the cross sectional shape of the second recess is V-shaped,
    The motor according to claim 11.
  13. 前記軸心を法線とする断面において、前記第２凹部の断面形状は、Ｕ字である、
    請求項１１に記載の電動機。     In the cross section normal to the axis, the cross-sectional shape of the second recess is a U shape.
    The motor according to claim 11.
  14. 請求項１～１３のいずれか１項に記載の電動機と、
    前記電動機が備える前記シャフトに取り付けられた回転ファンと、
    を備える、電動送風機。     An electric motor according to any one of claims 1 to 13,
    A rotating fan attached to the shaft of the motor;
    , Equipped with an electric blower.
  15. 請求項１４に記載の電動送風機と、
    前記電動送風機を制御する制御部と、
    を備える、電気掃除機。     An electric blower according to claim 14;
    A control unit that controls the electric blower;
    Equipped with a vacuum cleaner.
  16. 請求項１４に記載の電動送風機と、
    前記電動送風機を制御する制御部と、
    を備える、エアタオル。     An electric blower according to claim 14;
    A control unit that controls the electric blower;
    Equipped with an air towel.
PCT/JP2018/026971 2017-09-14 2018-07-18 Electric motor, electric air blower, electric vacuum cleaner, and air towel WO2019054047A1 (en)

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JP2017-176647 2017-09-14
JP2017176647A JP2021005910A (en) 2017-09-14 2017-09-14 Electric motor, electric blower, vacuum cleaner and air towel

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS53122703A (en) * 1977-03-31 1978-10-26 Shimadzu Corp Correcting unbalance for motor rotor and apparatus
JPS53147901A (en) * 1977-05-30 1978-12-23 Shimadzu Corp Method and apparatus for correcting motor-rotor unbalance
JPH04221523A (en) * 1990-12-25 1992-08-12 Matsushita Electric Works Ltd Hand dryer
US5871314A (en) * 1996-10-08 1999-02-16 Balance Systems S.R.L. Device for balancing rotors by material removal
JP2011101444A (en) * 2009-11-04 2011-05-19 Hitachi Appliances Inc Commutator motor, electric blower, power tool, and vacuum cleaner
JP2015142686A (en) * 2014-01-31 2015-08-06 株式会社東芝 Electric vacuum cleaner

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS53122703A (en) * 1977-03-31 1978-10-26 Shimadzu Corp Correcting unbalance for motor rotor and apparatus
JPS53147901A (en) * 1977-05-30 1978-12-23 Shimadzu Corp Method and apparatus for correcting motor-rotor unbalance
JPH04221523A (en) * 1990-12-25 1992-08-12 Matsushita Electric Works Ltd Hand dryer
US5871314A (en) * 1996-10-08 1999-02-16 Balance Systems S.R.L. Device for balancing rotors by material removal
JP2011101444A (en) * 2009-11-04 2011-05-19 Hitachi Appliances Inc Commutator motor, electric blower, power tool, and vacuum cleaner
JP2015142686A (en) * 2014-01-31 2015-08-06 株式会社東芝 Electric vacuum cleaner

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