CN112567598A - Stator and motor - Google Patents

Abstract

One embodiment of the stator of the present invention is a stator used for an outer rotor motor. The stator has: a stator core having a plurality of teeth arranged in a circumferential direction with respect to a central axis and extending in a radial direction; coils wound around the plurality of teeth, respectively; and a stator holder that holds the stator core. The stator core includes a plurality of core pieces having teeth and a coupling portion located closer to the center axis than the teeth. The stator holder has a first holder member and a second holder member that are axially opposed to each other and sandwich the stator core from both axial sides. The coupling portion has a through hole penetrating in the axial direction. At least one of the first holder member and the second holder member has a plurality of protrusions that are inserted into the through holes of the plurality of core pieces, respectively.

Description

Stator and motor

Technical Field

The invention relates to a stator and a motor.

Background

In a stator core formed by laminating electromagnetic steel sheets formed by punching and pressing, a split core is used in which the stator core is split for each tooth in order to improve the yield of the electromagnetic steel sheets at the time of pressing. In the inner rotor type motor, the split cores arranged in a ring shape are surrounded from the outside in the radial direction, whereby the split cores can be easily coupled to each other. However, in the outer rotor type motor, since the rotor is disposed radially outward of the stator core, it is difficult to connect the split cores from the radially outward side. Patent document 1 discloses an outer rotor type stator core having a structure in which teeth are fitted into recesses provided in an annular core.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2017-225311

Disclosure of Invention

Technical problem to be solved by the invention

In a stator using a split core, it is required to more firmly fix core pieces to each other.

In view of the above circumstances, an object of the present invention is to provide a stator having excellent joining strength between core segments and a motor having the stator.

Technical scheme for solving technical problem

One embodiment of the stator of the present invention is a stator used for an outer rotor motor. The stator has: a stator core having a plurality of teeth arranged in a circumferential direction with respect to a central axis and extending in a radial direction; coils wound around the plurality of teeth, respectively; and a stator holder that holds the stator core. The stator core includes a plurality of core pieces having the tooth portions and a coupling portion located closer to the central axis than the tooth portions. The stator holder has a first holder member and a second holder member that are axially opposed to each other and sandwich the stator core from both axial sides. The coupling portion has a through hole penetrating in the axial direction. At least one of the first holder member and the second holder member has a plurality of protrusions that are inserted into the through holes of the plurality of core pieces, respectively. In addition, one embodiment of the motor according to the present invention includes the stator and a rotor that surrounds the stator from a radially outer side and rotates around the central shaft.

Effects of the invention

According to one embodiment of the present invention, a stator having excellent connection strength between core pieces and a motor having the stator are provided.

Drawings

Fig. 1 is a sectional view of a motor according to an embodiment.

Fig. 2 is a plan view of a stator core according to an embodiment.

Fig. 3 is a perspective view of a core plate according to an embodiment.

Fig. 4 is a partially enlarged view of a stator core according to an embodiment.

Fig. 5 is an exploded view of an embodiment of a stator.

FIG. 6 is a cross-sectional schematic view of an embodiment of a stator.

Fig. 7 is a partial sectional view of a stator showing a projection of a modification.

Fig. 8 is an exploded perspective view showing a positional relationship between a core segment in which a part of a plurality of core segments are annularly arranged and a jig in a stator manufacturing method according to an embodiment.

Fig. 9 is an enlarged plan view of a part of a stator core according to a modification.

Fig. 10 is a perspective view of a core piece according to a modification.

Detailed Description

Hereinafter, a stator and a motor according to an embodiment of the present invention will be described with reference to the drawings. In the following drawings, scales, numbers, and the like of the respective structures may be different from those of actual structures in order to facilitate understanding of the respective structures.

The Z-axis is shown in the figures. The central axis J shown in the drawings is an imaginary line extending parallel to the Z-axis direction. In the following description, the axial direction of the central axis J, i.e., the direction parallel to the Z-axis direction, is simply referred to as the "axial direction", the radial direction about the central axis J is simply referred to as the "radial direction", and the circumferential direction about the central axis J is simply referred to as the "circumferential direction".

In this specification, the positive side in the Z-axis direction in the axial direction is sometimes referred to as "upper side", and the negative side in the Z-axis direction in the axial direction is sometimes referred to as "lower side". The vertical direction, the upper side, and the lower side are directions used for explanation only, and are not limited to an actual positional relationship and a posture of the motor when the motor is used.

In the present specification, a side that advances by rotating counterclockwise when viewed from above toward below, that is, a side that advances in the direction of arrow θ is referred to as a "circumferential side". The side that advances by rotating clockwise when viewed from the upper side toward the lower side in the circumferential direction, i.e., the side that advances in the direction opposite to the arrow θ direction, is referred to as the "other side in the circumferential direction".

< Motor >

Fig. 1 is a sectional view of a motor 1 of the present embodiment.

The motor 1 of the present embodiment is an outer rotor type motor. The motor 1 of the present embodiment is used as an in-wheel motor (japanese: インホイールモータ) of an electric automobile, for example. In addition, in the case where the motor 1 is used as an in-wheel motor, the motor 1 is supported by the vehicle in a state where the central axis J is arranged in the horizontal direction.

The motor 1 includes a stator 2, a rotor 7, a shaft 9, a bearing holder 60, a first bearing 61, and a second bearing 62. Although not shown in fig. 1, the motor 1 includes a bus bar connected to a coil wire extending from the stator 2, and a circuit board for controlling rotation of the rotor 7.

The shaft 9 is a cylindrical shaft extending along the center axis J. The shaft 9 is fixed to the stator 2. In the case where the motor 1 is used as an in-wheel motor, the shaft 9 is mounted to the frame of the vehicle so as not to be relatively rotatable.

A bearing holder 60 is fixed to the shaft 9. The bearing holder 60 is located on the lower side of the stator 2. The bearing holder 60 holds the second bearing 62 from the radially inner side. The bearing holder 60 is provided with a wire drawing hole 60a penetrating in the axial direction. The wiring extending from the stator 2 is drawn out to the outside of the motor 1 through the wiring drawing hole 60 a.

The rotor 7 rotates about the central axis J. The rotor 7 is rotated by a magnetic field generated by supplying a drive current from an external device to the stator 2. In the case where the motor 1 is used as an in-wheel motor, a rim, for example, is fixed to the rotor 7. The rotor 7 surrounds the stator 2 from the radially outer side.

The rotor 7 includes a rotor holder 72, a rotor magnet 71, a first cover member 73, and a second cover member 74.

The rotor holder 72 has a cylindrical shape extending in the axial direction about the central axis J. A first cover member 73 is fixed to an upper end of the rotor holder 72. Further, a second cover member 74 is fixed to a lower end portion of the rotor holder 72. The upper end of the rotor holder 72 corresponds to an axial end of the rotor holder 72. The lower end of the rotor holder 72 corresponds to the other axial end of the rotor holder 72.

The rotor magnet 71 is a permanent magnet having different magnetic poles arranged in the circumferential direction. The rotor magnet 71 is held on the inner peripheral surface of the rotor holder 72. The rotor magnet 71 is fixed to the inner peripheral surface of the rotor holder 72 by, for example, an adhesive.

The first cover member 73 has a circular disk shape when viewed from the axial direction. The first cover member 73 covers the upper side (one axial side) of the stator 2. The first cover member 73 is provided with a first center hole 73b located at the center in a plan view, and a first bearing holding portion 73a surrounding the first center hole 73 b. The shaft 9 passes through the first central hole 73 b. The first bearing holding portion 73a holds the first bearing 61 from the radial outside.

The second cover member 74 has a circular disk shape when viewed from the axial direction. The second cover member 74 covers the lower side (the other axial side) of the stator 2. The second cover member 74 is axially opposed to the first cover member 73. The stator 2 is disposed in a space surrounded by the rotor holder 72, the first cover member 73, and the second cover member 74.

The second cover member 74 is provided with a second center hole 74b located at the center in a plan view, and a second bearing holding portion 74a surrounding the second center hole 74 b. The shaft 9 and the bearing holder 60 are disposed radially inward of the second center hole 74 b. The second bearing holding portion 74a holds the second bearing 62 from the radially outer side.

The first bearing 61 and the second bearing 62 are arranged side by side in the axial direction. The first bearing 61 is located on the upper side of the stator 2 and the second bearing 62 is located on the lower side of the stator 2. The first bearing 61 is disposed radially between the rotor 7 and the shaft 9. The first bearing 61 supports the rotor 7 rotatably with respect to the shaft 9. The second bearing 62 is disposed radially between the rotor 7 and the bearing holder 60. The second bearing 62 supports the rotor 7 rotatably with respect to the bearing holder 60.

< stator >

The stator 2 of the present embodiment is a stator used in an outer rotor type motor. The stator 2 surrounds the shaft 9 from the radially outer side. The stator 2 is fixed to the outer peripheral surface of the shaft 9. The stator 2 includes a stator core 20 having teeth 21, a plurality of insulators 41, a plurality of coils 40, and a stator holder 8. The plurality of coils 40 are wound around the teeth 21 of the stator core 20 via insulators 41.

Fig. 2 is a plan view of stator core 20.

Stator core 20 has annular core back 28 and a plurality of teeth 21 extending radially outward from core back 28. The teeth 21 are arranged in the circumferential direction around the center axis J and extend in the radial direction. The coil 40 is wound around the tooth portion 21. In the present embodiment, 36 teeth 21 are provided on the stator core 20.

The stator core 20 is a so-called split core. The stator core 20 has a plurality of core pieces 20P and a plurality of connecting members 30. That is, the stator 2 has a plurality of core pieces 20P and a plurality of connecting members 30. In addition, the plurality of core pieces 20P and the plurality of connecting members 30 constitute the stator core 20. The connecting member 30 connects two core pieces 20P adjacent in the circumferential direction among the plurality of core pieces 20P.

In the present embodiment, the stator core 20 has the core pieces 20P and the connecting members 30, which are equal in number to each other. Therefore, one connecting member 30 connects only two core pieces 20P adjacent to each other. However, the core segment may be configured such that three or more core segments 20P are connected by one connecting member. In this case, the number of the core pieces is larger than the number of the connection members.

The plurality of core segments 20P are annularly arranged in the circumferential direction. That is, the plurality of core pieces 20P are arranged in the circumferential direction with respect to the central axis J. In the present embodiment, 36 core pieces 20P and 36 connecting members 30 are provided on the stator core 20. According to the present embodiment, since the stator core 20 includes the plurality of core segments 20P, the coil 40 can be wound in a state where the core segments 20P are separated from each other or in a state where the core segments 20P are separated from each other in the circumferential direction. Therefore, the tip of the nozzle of the winding machine is easily inserted between the core pieces 20P, and the coil 40 is easily wound tightly around the core pieces 20P. As a result, the space factor of the coil 40 in the slot can be increased.

Fig. 3 is a perspective view of the core piece 20P.

The core segment 20P is formed of electromagnetic steel sheets stacked in the axial direction. In the present embodiment, the outer shapes of the stacked electromagnetic steel sheets are all the same.

The core piece 20P has teeth 21, a connecting portion 22 located radially inside the teeth 21, and an umbrella portion 21a located radially outside the teeth 21. In the present embodiment, the core piece 20P includes one tooth portion 21 and one coupling portion 22. However, one core piece may have a structure having a plurality of coupling portions.

The teeth 21 extend radially with the same width. In the stator core 20, a plurality of teeth 21 are arranged at equal intervals in the circumferential direction. The umbrella portion 21a is wider in the circumferential direction with respect to the tooth portion 21. The radially outward surface of the umbrella portion 21a is formed in an arc shape centered on the central axis J when viewed in the axial direction.

The coupling portion 22 is located radially inward of the tooth portion 21. That is, the coupling portion 22 is located closer to the central axis J than the tooth portion 21. The coupling portion 22 is wider in the circumferential direction with respect to the tooth portion 21. That is, the dimension of the coupling portion 22 in the direction orthogonal to the radial direction is larger than the dimension of the tooth portion 21 in the direction orthogonal to the radial direction. The coupling portion 22 has a through hole (hole portion) 29 penetrating in the axial direction. That is, the core piece 20P has a through hole 29. According to the present embodiment, since each of the plurality of core pieces 20P has the through-hole 29, the stator core 20 can be reduced in weight.

Fig. 4 is a partially enlarged view of the stator core 20.

The through-hole 29 is disposed at a position sufficiently apart from the tooth portion 21 in the radial direction when viewed in the axial direction. Therefore, the cross-sectional area of the path of the magnetic flux passing from the tooth 21 to the connection 22 can be secured with a sufficient size. More specifically, the radial distance d between the through-hole 29 and the tooth portion 21 is preferably equal to or more than half (d.gtoreq.t/2) of the dimension t of the tooth portion 21 perpendicular to the radial direction. The magnetic flux passing through the coupling portion 22 from the tooth portion 21 is divided into two toward both sides in the circumferential direction at the coupling portion 22. That is, in the coupling portion 22, the magnetic flux directed to one side in the circumferential direction and the magnetic flux directed to the other side in the circumferential direction are each half of the magnetic flux passing through the tooth portion 21. By setting the distance d and the dimension t to the above relationship, the cross-sectional area of the magnetic flux passing through the connection portion 22 can be made equal to or more than half of the cross-sectional area of the magnetic flux passing through the tooth portion 21. Therefore, the magnetic flux density of the coupling portion 22 becomes equal to or less than the magnetic flux density of the tooth portion 21. As a result, the magnetic resistance of the stator core 20 in the connecting portion 22 can be reduced, and power saving of the motor 1 can be achieved.

The coupling portion 22 has a pair of end surfaces 22a, 22b facing opposite sides in the circumferential direction. Here, one of the pair of end surfaces 22a and 22b facing one side in the circumferential direction is defined as a first end surface 22a, and the other end facing the other side in the circumferential direction is defined as a second end surface 22b. The first end surface 22a and the second end surface 22b extend in the radial direction, respectively, as viewed in the axial direction. In the pair of core segments 20P adjacent in the circumferential direction, the second end surface 22b of the core segment 20P located on one circumferential side is in contact with the first end surface 22a of the core segment 20P located on the other circumferential side.

Here, a straight line extending in the radial direction through the center of the tooth portion 21 when viewed from the axial direction is taken as a reference line L. The first end surface 22a gradually separates from the reference line L toward one circumferential side as viewed in the axial direction, as it goes radially outward. That is, the first end surface 22a is inclined to one side in the circumferential direction with respect to the reference line L. The second end surface 22b gradually separates from the reference line L toward the other circumferential side as viewed in the axial direction. That is, the second end surface 22b is inclined to the other side in the circumferential direction with respect to the reference line L. In the present embodiment, the inclination angle of the first end face 22a with respect to the reference line L is equal to the inclination angle of the second end face with respect to the reference line L. The angle formed by the first end surface 22a and the second end surface 22b is, for example, 10 degrees.

According to the present embodiment, the coupling portions 22 adjacent in the circumferential direction contact each other, and the core back portion 28 in which the plurality of coupling portions 22 are annularly connected in the circumferential direction is configured. According to the present embodiment, the magnetic resistance of the stator core 20 can be reduced by having only one member boundary surface in the magnetic path passing between the core pieces 20P adjacent in the circumferential direction.

As a comparative example, a structure in which the connection members of the core segments adjacent in the circumferential direction are separated from each other and the connection members made of a magnetic material are connected to each other will be described. In the structure of the comparative example, the connecting member constitutes a part of the core back. Therefore, the number of the member boundary surfaces in the magnetic path between the circumferentially adjacent core pieces is two or more, and the magnetic resistance of the stator core 20 is larger than that of the present embodiment.

The first end surface 22a is provided with a projection 23 projecting to one side in the circumferential direction. In addition, a recess 24 that is recessed toward one side in the circumferential direction is provided on the second end surface 22b. That is, the coupling portion 22 has a convex portion 23 protruding from the first end surface 22a and a concave portion 24 recessed in the second end surface 22b. The outer shapes of the convex portion 23 and the concave portion 24 are arc-shaped when viewed from the axial direction.

In a pair of core segments 20P adjacent in the circumferential direction, the convex portion 23 of the core segment 20P located on the other side in the circumferential direction is embedded in the concave portion 24 of the core segment 20P located on one side in the circumferential direction. That is, in a state where the convex portion 23 enters the concave portion 24, the coupling portions 22 adjacent in the circumferential direction are fixed to each other by the connecting member 30.

According to the present embodiment, the convex portions 23 are fitted into the concave portions 24 in the coupling portions 22 adjacent in the circumferential direction, whereby the radial positional displacement between the coupling portions 22 adjacent in the circumferential direction can be suppressed. In addition, the alignment of the plurality of core pieces 20P with each other in the assembly process is facilitated.

According to the present embodiment, in the coupling portion 22 adjacent in the circumferential direction, a part of the outer peripheral surface of the convex portion 23 and a part of the inner peripheral surface of the concave portion 24 are opposed to and in contact with each other in the radial direction. Therefore, even when a radial force is applied to the single core piece 20P, the convex portion 23 and the concave portion 24 interfere with each other, and the movement of the core piece 20P is restricted. As a result, the connection strength between the core pieces 20P can be improved.

The coupling portion 22 has a first ridge 25 and a second ridge 26. The first ridge portion 25 and the second ridge portion 26 protrude radially inward. The first ridge 25 and the second ridge 26 extend in the same shape in the axial direction. The first ridge 25 and the second ridge 26 are arranged in the circumferential direction. The width dimension of the first raised strip 25 in the circumferential direction is equal to the width dimension of the second raised strip 26 in the circumferential direction. The end surface of the first raised strip 25 on the radially inner side of the coupling portion 22 is located at the end portion on the circumferential side. The end surface of the second raised strip 26 on the radially inner side of the coupling portion 22 is located on the other end in the circumferential direction. In the coupling portions 22 adjacent in the circumferential direction, the side surface of the second projected strip 26 of one coupling portion 22 and the side surface of the first projected strip 25 of the other coupling portion 22 contact each other in the circumferential direction.

The connecting member 30 is formed of electromagnetic steel sheets stacked in the axial direction. The outer shapes of the electromagnetic steel sheets stacked in the axial direction are all the same. In the stator core 20, the connecting member 30 is located radially inward of the coupling portion 22. The connecting members 30 connect the connecting portions 22 of the core pieces 20P adjacent in the circumferential direction to each other.

The connecting member 30 has a main body portion 31 and a pair of clamping portions 32. The body portion 31 extends in the circumferential direction. The pair of clamping portions 32 extend radially outward from both circumferential ends of the body portion 31.

The distance between the surfaces of the pair of sandwiching portions 32 facing each other is substantially equal to the sum of the width of the first raised strip 25 and the width of the second raised strip 26 of the core piece 20P in the circumferential direction. In the pair of core segments 20P adjacent in the circumferential direction, the second raised strip 26 of the core segment 20P on one circumferential side and the first raised strip 25 of the core segment 20P on the other circumferential side are sandwiched by the pair of sandwiching portions 32.

According to the present embodiment, the pair of holding portions 32 hold the first raised strip 25 provided on one of the circumferentially adjacent coupling portions 22 and the second raised strip 26 provided on the other of the circumferentially adjacent coupling portions 22. This makes it possible to fix and connect the pair of core segments 20P adjacent to each other in the circumferential direction.

According to the present embodiment, the plurality of core pieces 20P are connected by the plurality of connecting members 30. Therefore, the yield of the electromagnetic steel sheet can be easily improved in the step of punching the connecting member 30, as compared with the case where a plurality of core pieces are connected by an annular connecting member. As a result, the stator 2 can be manufactured at low cost.

According to the present embodiment, the number of the core pieces 20P and the number of the connection members 30 are the same as each other. Further, one connecting member 30 connects the connecting portions 22 of a pair of core pieces adjacent in the circumferential direction to each other. In the punching press, the smaller the size of the molded product, the closer the shape of the molded product is to a rectangular shape, and the easier the yield of the material is to be improved. According to the present embodiment, the connecting member 30 can be reduced in size and can be close to a rectangular shape, and therefore, the yield of the material (electromagnetic steel sheet) to be punched and stamped can be more easily improved.

In the present embodiment, a case where the pair of core pieces 20P are connected to each other by one connecting member 30 is described. However, as long as the stator core 20 has a plurality of connecting members 30, three or more core pieces may be connected by one connecting member.

According to the present embodiment, the connecting member 30 is composed of electromagnetic steel sheets stacked in the axial direction. Therefore, in the stator core 20 of the present embodiment, the connecting member 30 can pass the magnetic flux through the inside as a part of the core back portion 28. That is, according to the present embodiment, by using the connecting member 30 as a part of the core back 28, the radial dimension of the core back 28 can be increased, and the magnetic resistance of the stator core 20 can be reduced.

According to the present embodiment, the connection members 30 are stacked in the axial direction. The pair of sandwiching portions 32 sandwich the first raised strip 25 and the second raised strip 26, and thus the pair of sandwiching portions 32 receive a reaction force in the circumferential direction from the first raised strip 25 and the second raised strip 26. According to the present embodiment, the reaction force received by the connecting member 30 from the connecting portion 22 can be set to a direction intersecting the stacking direction of the electromagnetic steel sheets, and separation of the stacked electromagnetic steel sheets can be suppressed.

In the present embodiment, the stator core 20 having the connection member 30 made of an electromagnetic steel plate is explained. However, according to the structure of the stator core 20 of the present embodiment, a resin material may be used as the material of the connecting member. In this case, the connecting member is molded by injection molding. Generally, injection molding is less expensive to manufacture and has a higher yield of material than blanking and stamping. That is, by adopting the structure of the present embodiment, the connecting member 30 can be made of a resin material, and a stator core which is easy to improve the yield of the material and is inexpensive can be provided.

Stator holder

As shown in fig. 1, the stator holder 8 is disposed radially between the stator core 20 and the shaft 9. The stator holder 8 holds the stator core 20. The stator holder 8 is fixed to the outer peripheral surface of the shaft 9 via a bush 9 a.

Fig. 5 is an exploded view of the stator 2. Fig. 6 is a schematic sectional view of the stator 2 mainly showing the stator holder 8.

The stator holder 8 has a first holder member 81 and a second holder member 86 that are opposite to each other in the axial direction. In the present embodiment, the first holder member 81 and the second holder member 86 have the same shape.

The first holder member 81 includes a cylindrical portion 81a, a bottom plate portion 81b, a flange portion 81c, and a shaft support portion 81 d. Similarly, the second holder member 86 includes a cylindrical portion 86a, a bottom plate portion 86b, a flange portion 86c, and a shaft support portion 86 d.

As shown in fig. 6, the cylindrical portions 81a, 86a of the first and second holder members 81, 86 are located radially inward of the stator core 20. That is, the cylindrical portions 81a and 86a are located radially inward of the plurality of core pieces 20P. The cylindrical portions 81a and 86a extend in the axial direction around the central axis J. The outer peripheral surfaces of the cylindrical portions 81a, 86a contact the connecting member 30 from the radially inner side. In the present embodiment, the cylindrical portion 81a of the first holder member 81 is in contact with the region of the upper half of the joint member 30, and the cylindrical portion 86a of the second holder member 86 is in contact with the region of the lower half of the joint member 30. The cylindrical portions 81a and 86a restrict the movement of the connecting member 30 radially inward, and prevent the connecting member 30 from coming off the coupling portion 22 of the core piece 20P. Thereby, the stator holder 8 suppresses the release of the connection between the plurality of core pieces 20P. In the present embodiment, the first holder member 81 and the second holder member 86 have cylindrical portions 81a and 86a, respectively, which are in contact with the connecting member 30. However, as long as at least one of the first and second holder members 81 and 86 has a cylindrical portion that is in contact with the connecting member 30.

The flange portion 81c of the first holder member 81 extends radially outward from the upper end of the cylindrical portion 81 a. The flange portion 86c of the second holder member 86 extends radially outward from the lower end of the cylindrical portion 86a. The flanges 81c and 86c are annular around the central axis J. The flange portion 81c of the first holder member 81 and the flange portion 86c of the second holder member 86 are axially opposed to each other.

The flange portion 81c of the first holder member 81 is in contact with the upper end surface of the connecting member 30. Similarly, the flange portion 86c of the second holder member 86 contacts the lower end surface of the connecting member 30. Thus, the flanges 81c and 86c restrict the movement of the connecting member 30 in the axial direction, and prevent the connecting member 30 from coming off the coupling portion 22 of the core piece 20P.

The flange 81c of the first holder member 81 contacts the upper end surfaces of the coupling portions 22 of the plurality of core pieces 20P. Similarly, the flange portion 86c of the second holder member 86 contacts the lower end surfaces of the coupling portions 22 of the plurality of core pieces 20P. That is, the first holder member 81 and the second holder member 86 are opposed to each other in the axial direction, and sandwich the stator core 20 from both sides in the axial direction. Thereby, the first holder member 81 and the second holder member 86 suppress the positional displacement of the plurality of core pieces 20P in the axial direction. In addition, the first holder member 81 and the second holder member 86 firmly hold the plurality of core pieces 20P and support the coupling of the plurality of core pieces 20P.

The flange portion 81c of the first holder member 81 is provided with a plurality of projecting portions 82 projecting downward. Similarly, the flange portion 86c of the second holder member 86 is provided with a plurality of projecting portions 82 projecting upward. The protrusions 82 of the first holder member 81 and the second holder member 86 are inserted into the through-holes 29 provided in the core piece 20P. In the present embodiment, 36 protruding portions 82, the number of which is the same as that of the through-holes 29, are provided on the first holder member 81 and the second holder member 86, respectively. All the protrusions 82 are inserted into the through-holes 29.

According to the present embodiment, the rotation of the stator holder 8 about the central axis J is suppressed by inserting the protrusion 82 into the through-hole 29 of the stator core 20. That is, the protrusion 82 functions as a rotation stopper of the stator holder 8 with respect to the stator core 20.

According to the present embodiment, the protrusions 82 are inserted into the through holes 29 of all the core pieces 20P. The protrusion 82 restricts the movement of the core piece 20P in the radial direction. Thereby, the stator holder 8 suppresses the release of the connection between the plurality of core pieces 20P.

In the present embodiment, the case where the protrusion 82 is provided in both the first holder member 81 and the second holder member 86 is shown. However, as long as at least one of the first holder member 81 and the second holder member 86 is provided with the protruding portion 82, the release of the coupling of the plurality of core pieces 20P can be suppressed. Further, both the first holder member 81 and the second holder member 86 can suppress the movement of the core pieces 20P in balance at both end portions in the axial direction of the stator holder 8 by the same number of the protrusion portions 82 as the number of the through-holes 29. Therefore, according to the present embodiment, the effect of releasing the connection of the plurality of core pieces 20P can be improved.

The protrusion 82 of the present embodiment is formed by caulking the flanges 81c and 86 c. As shown in fig. 5, the flanges 81c and 86c before the assembly process are flat. The protrusion 82 is formed by applying a force to the portions of the flange portions 81c, 86c that overlap the through-hole 29 in a state where the flange portions 81c, 86c are in contact with the upper surface or the lower surface of the stator core 20, respectively, and plastically deforming the portions.

Fig. 7 is a partial cross-sectional view of the stator 2 showing a projection 82A of a modification that can be employed in the present embodiment. Similarly to the projection 82, the projection 82A of the present modification is formed by deforming a part of the flange 81 c. The projection 82A of the present modification is formed by applying a force to a portion of the flange 81c overlapping the through-hole 29, thereby breaking a portion of the flange and bending the flange downward. Even in the case of using the projection 82A of the present modification, the same effect as the projection 82 can be obtained.

The structure of the protrusion is not limited to the above embodiment and the modifications. For example, a different member may be fixed to the lower surface of the flange portion as the protrusion portion.

As shown in fig. 6, the bottom plate portion 81b of the first holder member 81 and the bottom plate portion 86b of the second holder member 86 extend along a plane orthogonal to the central axis J. The bottom plate portions 81b, 86b are located radially inward of the stator core 20. The bottom plate portions 81b and 86b are disk-shaped with the central axis J as the center. Radially outer ends of the bottom plate portions 81b, 86b are connected to the cylindrical portions 81a, 86a. The radially inner ends of the bottom plate portions 81b and 86b are connected to the shaft support portions 81d and 86 d. That is, the bottom plate portions 81b and 86b are respectively positioned between the shaft support portions 81d and 86d and the cylindrical portions 81a and 86a in the radial direction.

As shown in fig. 5, the bottom plate portion 81b of the first holder member 81 and the bottom plate portion 86b of the second holder member 86 are in contact with each other in the axial direction. Further, the bottom plate portions 81b, 86b of the first holder member 81 and the second holder member 86 are fixed to each other.

According to the present embodiment, the stator core 20 can be sandwiched from the axial direction by the first holder member 81 and the second holder member 86. This ensures the fixing strength of the stator holder 8 and the stator core 20, and improves the coupling strength between the core pieces 20P.

First fixing holes (fixing holes) 83, second fixing holes 84, and fixing projections 85 are provided in the bottom plate portions 81b, 86b of the first holder member 81 and the second holder member 86, respectively. In the present embodiment, three first fixing holes 83, three second fixing holes 84, and three fixing protrusions 85 are provided in the bottom plate portions 81b and 86b.

The first fixing hole 83 and the second fixing hole 84 penetrate in the axial direction. The first fixing hole 83 and the second fixing hole 84 are circular when viewed from the axial direction. The diameter of the first fixing hole 83 is slightly larger than that of the second fixing hole 84. In the bottom plate portions 81b, 86b, the first fixing holes 83 and the second fixing holes 84 are alternately arranged in the circumferential direction. The first fixing hole 83 of the first holder member 81 and the second fixing hole 84 of the second holder member 86 overlap each other when viewed from the axial direction. Likewise, the first fixing hole 83 of the second holder member 86 and the second fixing hole 84 of the first holder member 81 overlap each other when viewed in the axial direction.

The fixing projection 85 protrudes in an axial direction cylindrically from the outer edge of the second fixing hole 84. The fixing protrusion 85 of the first holder member 81 protrudes downward (i.e., the second holder member 86 side). On the other hand, the fixing protrusion 85 of the second holder member 86 protrudes upward (i.e., toward the first holder member 81).

As shown in fig. 6, the fixing projection 85 of the second holder member 86 is inserted into the first fixing hole 83 of the first holder member 81. The front end of the fixing projection 85 of the second holder member 86 is located above the bottom plate portion 81b of the first holder member 81. A caulking portion 85a extending outward from the center of the second fixing hole 84 is provided at the tip of the fixing protrusion 85 of the second holder member 86. The caulking portion 85a is formed by caulking for plastically deforming the tip of the fixing protrusion 85. The caulking portion 85a and the bottom plate portion 86b of the second holder member 86 sandwich the bottom plate portion 81b of the first holder member 81 in the axial direction. Thereby, the first holder member 81 and the second holder member 86 are fastened to each other. According to the present embodiment, the first holder member 81 and the second holder member 86 can be fixed to each other by performing caulking. In addition, according to the present embodiment, since the first holder member 81 and the second holder member 86 are fixed without using another member, the motor 1 can be manufactured at low cost.

Here, the relationship between the first fixing hole 83 of the first holder member 81, the second fixing hole 84 of the second holder member 86, and the fixing protrusion 85 is described with reference to fig. 6. However, the same structure is also applied to the relationship between the first fixing hole 83 of the second holder member 86, and the second fixing hole 84 and the fixing projection 85 of the first holder member 81. In the present embodiment, the first holder member 81 and the second holder member 86 have three fixing projections 85, respectively. Therefore, the first holder member 81 and the second holder member 86 are fixed to each other at six locations in the circumferential direction in total.

The shaft support portion 81d of the first holder member 81 has a cylindrical portion 81da and a conical portion 81 db. The cylindrical portion 81da has a cylindrical shape centered on the central axis J. The cylindrical portion 81da contacts the outer peripheral surface of the bush 9a fixed to the shaft 9. The conical portion 81db extends radially outward from the upper end of the cylindrical portion 81 da. The conical portion 81db is conical about the central axis J. The conical portion 81db extends downward as it goes radially outward. The radially outer end of the conical portion 81db is connected to the bottom plate portion 81 b.

The shaft support portion 86d of the second holder member 86 has a cylindrical portion 86da and a conical portion 86 db. The shaft support portion 86d of the second holder member 86 has a shape in which the shaft support portion 81d of the first holder member 81 is inverted in the vertical direction, and has the same configuration.

According to the present embodiment, the stator holder 8 is fitted and fixed to the outer peripheral surface of the bush 9a in the cylindrical portions 81da and 86 da. Therefore, the fitting length can be sufficiently ensured in the axial direction. As a result, the stator holder 8 can be firmly fixed to the bush 9 a.

< production method >

Next, a method for manufacturing the stator 2 of the present embodiment will be described. That is, the stator 2 of the present embodiment is manufactured by the manufacturing method described below.

The method of manufacturing the stator 2 of the present embodiment mainly includes a core piece preparation step, a first arrangement step, a winding step, a second arrangement step, a third arrangement step, a connection step, and a holder fixing step. The processing steps of the method for manufacturing the stator 2 are performed in the order described above.

(iron chip preparation Process)

The core piece preparation step is a step of preparing a plurality of core pieces 20P and mounting the insulator 41 on each tooth portion 21. The core segment 20P is manufactured by laminating a plurality of electromagnetic steel sheets formed by punching and pressing in the axial direction and connecting the electromagnetic steel sheets to each other by caulking or the like. In the present embodiment, 36 core pieces 20P are prepared for each stator 2.

(first preparation Process)

The first arrangement step is a preliminary step for winding the coil 40 around the core piece 20P. The first arrangement step is a step of arranging a plurality of core pieces 20P for easy winding. The first disposing step is a step of disposing the plurality of core pieces 20P in the circumferential direction with respect to the central axis J.

Before the first arrangement step, the plurality of core pieces 20P are first classified into two or more groups. In the present embodiment, before the first arranging step, 36 core pieces 20P are classified into two groups of 18 core pieces 20P. The first arrangement process is performed for each of the groups classified into two or more iron core pieces 20P.

In the present specification, a group refers to a single or a collection of a plurality of core pieces 20P. That is, the core pieces 20P belonging to one group may be singular. In addition, since the first arrangement process cannot be performed, all the groups of the core pieces 20P are not classified into a singular number.

As shown in fig. 8, in the first arrangement step, the core pieces 20P of each group are arranged in a ring shape. At this time, in the core piece 20P, the tooth portions 21 are arranged in the radial direction with the coupling portions 22 on the radially inner side. Therefore, in the first arranging step, the core pieces 20P are radially arranged around the central axis J.

According to the first arrangement process, the plurality of core pieces 20P are arranged at the first arrangement angle with respect to each other

Are radially arranged. That is, in the first arrangement step, the angle formed by the two adjacent core pieces 20P and the central axis J is set as the first arrangement angle

A plurality of core pieces 20P are arranged. The first arrangement process is performed for each group of the core pieces 20P classified into two or more groups. Therefore, the number of the core segments 20P arranged in the first arranging step is smaller than the total number of the core segments 20P used in the stator 2. Thus, the first disposition angle

Is larger than the angle formed by the core pieces 20P in the final stator core 20 (the second arrangement angle shown in fig. 2)

). In the present embodiment, the core pieces 20P are divided into two halves to form respective groups, and the core pieces 20P of the respective groups are annularly arranged, so that the first arrangement angle

Is a second disposition angle

Twice as much.

In the first arrangement step, the jig 90 shown in fig. 8 is used. That is, the first arranging process uses the jig 90.

The jig 90 has a disk-shaped base 92 and a plurality of holding projections 91 projecting from the base 92. The holding projection 91 projects upward from the upper surface of the jig 90. The retaining projection 91 extends in the axial direction. The plurality of holding projections 91 are arranged in the circumferential direction around the center axis J. In the present embodiment, each of the plurality of holding projections 91 has a pair of pins 91a. The pair of pins 91a has a cylindrical shape extending in parallel with each other in the axial direction. The pair of pins 91a are arranged in the circumferential direction.

In the first arrangement process, the holding projections 91 of the jig 90 are inserted into the through-holes 29 of the respective groups of the core pieces 20P. That is, the first arrangement step is a step of inserting the holding projections 91 into the through holes 29 of the plurality of core pieces 20P in each group. The plurality of core pieces 20P inserted by the holding projection 91 are not angularly adjusted, but are aligned in the circumferential direction at the first arrangement angle. That is, according to the present embodiment, the first disposing step can be easily performed.

The through-hole 29 of the core piece 20P is an elongated hole extending in a direction orthogonal to the radial direction when viewed in the axial direction. The through hole 29 has a size in the radial direction equal to or slightly larger than the diameter of the pin 91a. In a state where the holding projection 91 is inserted into the through-hole 29, the pair of pins 91a are aligned in the longitudinal direction of the through-hole. Therefore, in a state where the holding projection 91 is inserted into the through-hole 29, the rotation of the core piece 20P around the holding projection 91 is suppressed. This makes it possible to uniquely determine the angle of the core segment 20P with respect to the jig 90.

In the present embodiment, the holding projection 91 is inserted into the through hole 29 of the core piece 20P. However, the hole into which the holding projection 91 is inserted may not necessarily penetrate the core piece 20P. That is, if the core piece 20P has a hole portion extending in the axial direction and opening in the axial direction, the holding projection 91 can be inserted into the hole portion and supported by the jig.

(winding step)

The winding step is a step of winding the coil 40 around the tooth portions 21 of the core piece 20P via the insulator 41. The winding process is performed for each group of the core pieces 20P having completed the first arrangement process. That is, the winding process is performed for each set of the core pieces 20P. The winding process is performed in a state where the core piece 20P is held by the jig 90 shown in fig. 8.

According to the present embodiment, the plurality of core pieces 20P performing the winding process are arranged at the first arrangement angle in the circumferential direction

And (4) arranging. First configuration angle

Is greater than the second disposition angle

The angle of (c). Therefore, the gap between the core pieces 20P subjected to the winding process is wider than that of the final stator core 20. According to the present embodiment, the tip of the nozzle of the winding machine that performs the winding process can be easily inserted between the core pieces 20P. Therefore, the second arrangement angle is formed between the plurality of ferrite pieces 20P

In comparison with the case where the winding step is performed in the aligned state, the winding step is easier, and the space factor of the coil is easier to increase. This effect is more pronounced in stators 2 having a larger number of slots.

According to the present embodiment, the coil 40 can be continuously wound around the plurality of core pieces 120P in the circumferential direction. Therefore, the winding efficiency can be improved as compared with the case where the coils are individually wound around the plurality of core pieces 120P. Further, since the plurality of core pieces 120P are arranged in the circumferential direction, a crossover wire for connecting the coils 40 can be provided in the winding step. In addition, in the case of adopting the method for manufacturing the stator 2 according to the present embodiment, since the winding process can be performed using an existing winding machine, a new equipment investment is not required.

The order of winding the plurality of coils 40 in the winding step is not particularly limited. The order of providing lead wires for connection to the bus bars is not particularly limited. For example, a method may be employed in which all the coils 40 in a group are wound in series in the circumferential direction, and then a part of the crossover is cut to form a lead wire.

(second preparation Process)

The second arranging step is to arrange the plurality of core pieces 20P in the group at a second arranging angle

(see FIG. 2) a step of arranging the substrates in the circumferential direction. The second arranging step is performed on the group of core pieces 20P having completed the winding step. In the second arrangement step, the angle formed by the two adjacent core pieces 20P and the central axis J is set to a second arrangement angle

In addition, as described above, the second arrangement angle

Is at a greater angle than the first disposition

A small angle. The second arranging step is performed by detaching each group of the plurality of core pieces 20P from the jig 90.

(third preparation Process)

The third arranging step is performed after the second arranging step. The third arrangement step is a step of arranging the plurality of groups subjected to the second arrangement step in a ring shape in the circumferential direction. By performing the third arranging step, all the core pieces 20P of the stator core 20 can be annularly arranged, and the shape of the stator core 20 can be formed.

(joining step)

The connection process is to arrange the second arrangement angle

And a step of connecting the core segments adjacent in the circumferential direction. As shown in fig. 2, in the joining step, the connecting members 30 are attached to the joining portions 22 of the core pieces 20P adjacent in the circumferential direction and joined to each other. The joining step is a step of forming the stator core 20. That is, the second arrangement angle is formed by the connection process

And stator cores 20 of core pieces 20P arranged in the circumferential direction.

In the present embodiment, the connecting step is performed after the third step. Therefore, in the present embodiment, the connection process is performed for the plurality of core segments 20P arranged annularly in the circumferential direction. According to the connection step of the present embodiment, all the core pieces 20P can be connected at once by using a jig or the like, and there is an advantage that the workability of the connection step is easily improved.

(modification of connection step)

The joining step may be performed again to join the groups after the group classification. In this case, the joining step includes a first joining step performed for each group and a second joining step of joining the groups to each other. The first joining step is performed after the second arranging step, and joins the core segments 20P adjacent in the circumferential direction to each other in the group. The second joining step is performed after the third arranging step, and joins the core segments 20P positioned at the circumferential end portions of the adjacent groups to each other.

According to the connection step of the present modification, after the core pieces 20P are connected for each group in the first connection step, the groups are connected to each other in the second connection step. Therefore, when the coupling step of the present modification is adopted, the method for manufacturing the stator 2 is performed in the order of the first coupling step, the third arranging step, and the second coupling step. According to this modification, since the core pieces 20P in the group are connected to each other before the third arranging step, handling is easy for each group, and workability in the third arranging step is improved.

(holder fixing step)

The holder fixing step is a step of attaching the stator holder 8 to the stator core 20. The holder fixing step is performed after the connecting step is completed. The stator core 20 for performing the holder fixing process has a second arrangement angle

A plurality of core pieces 20P arranged in the circumferential direction.

As shown in fig. 6, the stator holder 8 has a first holder member 81 and a second holder member 86. The retainer fixing step of the present embodiment includes a fastening step and a protrusion forming step performed after the fastening step.

The fastening process is a process of fastening the first holder member 81 and the second holder member 86 to each other in the axial direction. The fastening step of the present embodiment is a step of fixing the first holder member 81 and the second holder member 86 to each other by caulking.

In the fastening process, first, the cylindrical portion 81a of the first holder member 81 is inserted from the upper side into the radial inside of the stator core 20, and the cylindrical portion 86a of the second holder member 86 is inserted from the lower side into the radial inside of the stator core 20. Further, the flange portion 81c of the first holder member 81 is brought into contact with the upper surface of the stator core 20, and the flange portion 86c of the second holder member 86 is brought into contact with the lower surface of the stator core 20. Simultaneously with these steps, the fixing protrusion 85 of the second holder member 86 is inserted into the first fixing hole 83 of the first holder member 81. In addition, although illustration is omitted, simultaneously, the fixing protrusion 85 of the first holder member 81 is inserted into the first fixing hole 83 of the second holder member 86.

In the fastening step, the tip of the fixing projection 85 is swaged outward with respect to the center of the second fixing hole 84 to form a swaged portion 85a. Thereby, the first holder member 81 and the second holder member 86 are fastened to each other.

The protrusion forming step is a step of plastically deforming a part of the first holder member 81 and the second holder member 86 (the flange portions 81c, 86c in the present embodiment) and forming the protrusion 82, respectively. The protrusion forming step is a step of forming the protrusion 82 and inserting the protrusion 82 into the through-hole 29 of the stator core 20. The formation of the protrusion 82 and the insertion of the protrusion 82 into the through-hole 29 are performed simultaneously.

In the protrusion forming step, first, a force is applied to the portions of the flanges 81c and 86c that overlap the through-hole 29. This plastically deforms the flange portions 81c, 86c, and forms the protrusion 82 inserted into the through-hole 29.

In addition, in the protrusion forming step of the present embodiment, the protrusion 82 is formed in both the first holder member 81 and the second holder member 86. However, the protrusion forming step may be performed by forming the protrusion 82 on at least one of the first holder member 81 and the second holder member 86.

< modification of stator core >

Next, a stator core 120 according to a modification example that can be adopted in the above embodiment will be described.

The same reference numerals are given to the constituent elements of the same embodiment and the description thereof is omitted.

Fig. 9 is an enlarged plan view of a part of stator core 120 according to the present modification.

As in the above embodiment, the stator core 120 includes an annular core back portion 128 and a plurality of tooth portions 121 extending radially outward from the core back portion 128. The teeth 121 are arranged in the circumferential direction around the center axis J and extend in the radial direction.

The stator core 120 includes a plurality of core pieces 120P and a plurality of connecting members 130 that connect the core pieces 120P to each other. The plurality of core segments 120P are annularly arranged in the circumferential direction.

Fig. 10 is a perspective view of the core piece 120P.

The core piece 120P includes teeth 121, a coupling portion 122 located closer to the central axis J than the teeth 121, and an umbrella portion 121a located radially outward of the teeth 121. The tooth 121 and the umbrella 121a of this modification have the same configuration as that of the above-described embodiment.

As in the above-described embodiment, the coupling portion 122 is located at the radially inner end of the tooth portion 121. The coupling portion 122 is provided with a through hole 129 that penetrates in the axial direction. The circumferentially adjacent coupling portions 122 are connected in a ring shape while contacting each other, and constitute a core back portion 128. A convex portion 123 is provided on one circumferential end surface of the coupling portion 122, and a concave portion is provided on the other circumferential end surface. In a pair of core segments 120P adjacent in the circumferential direction, the convex portion 123 is fitted in the concave portion 124.

The coupling portion 122 of the present modification includes a first arm portion 122A and a second arm portion 122B extending radially inward. The first arm portion 122A and the second arm portion 122B are located at radially inward end portions of the coupling portion 122. The first arm portion 122A and the second arm portion 122B are arranged in the axial direction. The first arm portion 122A and the second arm portion 122B each have the same cross-sectional shape in the axial direction.

The first arm portion 122A and the second arm portion 122B are in line symmetry with each other with respect to the reference line L when viewed in the axial direction. The first arm portion 122A extends radially inward. The first arm portion 122A extends to one circumferential side as it goes to the radially inner side. The second arm portion 122B extends radially inward. The second arm portion 122B extends to the other circumferential side as it goes to the radially inner side. That is, the direction in which the first arm portion 122A extends radially inward is circumferentially offset from the direction in which the second arm portion 122B extends radially inward. The first arm portion 122A and the second arm portion 122B extend in mutually different directions in the circumferential direction as they go radially inward.

The core piece 120P is provided with two first arm portions 122A and two second arm portions 122B. The first arm portions 122A and the second arm portions 122B are alternately arranged in the axial direction. The two first arm portions 122A and the two second arm portions 122B are all equal in axial dimension.

The core segment 120P is formed of electromagnetic steel sheets stacked in the axial direction. The shapes of the electromagnetic steel sheets of the region having the first arm portion 122A and the region having the second arm portion 122B in the axial direction are different from each other. That is, the core segment 120P of the present modification is formed by laminating a plurality of electromagnetic steel sheets having different shapes in the axial direction.

In the adjacent core pieces 120P of the stator core 120, the first arm portion 122A and the second arm portion 122B overlap in the axial direction. That is, in a pair of core segments 120P adjacent in the circumferential direction, the first arm portion 122A of one core segment 120P and the second arm portion 122B of the other core segment 120P overlap each other when viewed from the axial direction. Further, the surfaces of the first arm portion 122A and the second arm portion 122B which are opposed in the axial direction are in contact with each other. According to this modification, it is possible to suppress the core segments 120P adjacent in the circumferential direction from being displaced relative to each other in the axial direction. As a result, the stability of the connection between the core pieces 120P is improved. In addition, the positioning of the core pieces 120P in the axial direction in the assembly process is facilitated.

Although the number of the first arm portions 122A and the second arm portions 122B provided in the connecting portion 122 is not limited, at least one of them is preferably two or more. As an example, a case where two or more first arm portions 122A are provided on one core piece 120P will be described. In this case, in the adjacent core pieces 120P, the second arm portion 122B is sandwiched between the two first arm portions 122A in the axial direction. Therefore, the core pieces 120P are restricted from moving relative to each other to both axial sides.

As shown in fig. 10, the first arm portion 122A has a pair of end surfaces 122Aa and 122Ab facing opposite sides in the circumferential direction. That is, the coupling portion 122 has a first end surface 122Aa and a second end surface 122Ab. Here, one of the pair of end surfaces 122Aa and 122Ab facing one side in the circumferential direction is defined as a first end surface 122Aa, and the other end facing the other side in the circumferential direction is defined as a second end surface 122Ab.

The first end surface 122Aa extends radially inward. The first end surface 122Aa is inclined to the circumferential direction side as it goes radially inward. The second end surface 122Ab extends radially inward. The second end surface 122Ab is inclined to the circumferential side as it goes radially inward. That is, the first end surface 122Aa and the second end surface 122Ab are inclined in the same direction with respect to the reference line L when viewed from the axial direction.

As shown in fig. 9, in a pair of core segments 120P adjacent in the circumferential direction, the second end surface 122Ab of the core segment 120P located on one circumferential side and the first end surface 122Aa of the core segment 120P located on the other circumferential side are in contact with each other. That is, in the circumferentially adjacent connecting portions 122, the end surfaces 122Aa and 122Ab of the first arm portions 122A contact each other.

According to the present modification, end surfaces 122Aa and 122Ab inclined in the same direction in the circumferentially adjacent connecting portions 122 are in contact with each other. Therefore, in the case where a radial force is applied to the single core piece 120P in the stator core 120, the end faces 122Aa, 122Ab interfere with each other, and movement of the core piece 120P in the radial direction is restricted. As a result, the connection strength between the core pieces 120P can be improved.

As shown in fig. 10, the second arm portion 122B has a pair of end surfaces 122Ba and 122Bb facing opposite sides in the circumferential direction, similarly to the first arm portion 122A. Here, one of the pair of end surfaces 122Ba and 122Bb facing one side in the circumferential direction is defined as a third end surface 122Ba, and the other end facing the other side in the circumferential direction is defined as a fourth end surface 122Bb.

The third end surface 122Ba extends radially inward. The third end surface 122Ba is inclined to the other circumferential side as it goes radially inward. The fourth end surface 122Bb extends radially inward. The fourth end surface 122Bb is inclined to the other circumferential side as facing the radially inner side. That is, the third end surface 122Ba and the fourth end surface 122Bb are inclined in the same direction with respect to the reference line L when viewed from the axial direction.

In fig. 9, the first arm portion 122A is indicated by a solid line, and the second arm portion 122B is indicated by a broken line.

As shown in fig. 9, in the coupling portions 122 adjacent in the circumferential direction, the end surfaces 122Ba, 122Bb of the second arm portions 122B contact each other. Therefore, in the stator core 120, the end surfaces 122Ba and 122Bb of the adjacent coupling portions 122 interfere with each other, and movement of the core piece 120P in the radial direction is restricted.

In the present modification, the inclination directions of the end surfaces 122Aa and 122Ab of the first arm portion 122A and the inclination directions of the end surfaces 122Ba and 122Bb of the second arm portion 122B are opposite to each other with respect to the reference line L. Therefore, in the stator core 120, in the case where a radial force is applied to a single core piece 120P, the directions of the circumferential directions that the first arm portion 122A and the second arm portion 122B respectively receive from the adjacent core pieces 120P are opposite directions to each other. Therefore, the movement of the core segments 120P in the circumferential direction when a force is applied to the core segments 120P is suppressed, and the coupling force of the plurality of core segments 120P is improved.

In the present modification, the end surfaces 122Aa, 122Ab, 122Ba, and 122Bb of the first arm portion 122A and the second arm portion 122B are linearly inclined when viewed from the axial direction. However, the end surfaces 122Aa, 122Ab, 122Ba, and 122Bb may be curved surfaces.

Groove portions 125 are provided at radially inner end portions of the first arm portion 122A and the second arm portion 122B, respectively. The recessed portion 125 extends in the axial direction. In addition, the groove portion 125 is open on the radially inner side.

In a pair of core pieces 120P adjacent in the circumferential direction, the first arm portion 122A of one core piece 120P and the second arm portion 122B of the other core piece 120P overlap each other when viewed from the axial direction. In addition, in the first arm portion 122A and the second arm portion 122B overlapped with each other, the respective groove portions 125 are connected in the axial direction. The connection member 130 is fitted into the groove portion 125 connected in the axial direction.

The connecting member 130 is located radially inward of the coupling portion 122 of the core piece 120P. The connecting member 130 connects the first arm portion 122A and the second arm portion 122B of the core pieces 120P adjacent in the circumferential direction. In the present modification, the connecting member 130 has a rectangular shape when viewed from the axial direction. The connection member 130 has a rod shape extending in the axial direction.

The groove portion 125 extends across the first arm portion 122A and the second arm portion 122B of the core pieces 120P adjacent in the circumferential direction. The connection members 130 are fitted into the groove portions 125, whereby the core pieces 120P adjacent in the circumferential direction are coupled to each other.

As shown in fig. 10, the groove portion 125 has a pair of opposing faces 125a. The pair of opposing faces 125a are parallel to each other. The pair of opposing faces 125a circumferentially oppose each other. In addition, a pair of opposing faces extend in the radial direction. The connecting member 130 is sandwiched between the pair of opposing surfaces 125a. Therefore, the distance between the pair of opposing faces 125a is substantially equal to the dimension of the connecting member 130 orthogonal to the radial direction.

The pair of opposing surfaces 125a are inclined at an angle α with respect to the reference line L as viewed in the axial direction. That is, the insertion direction of the connection member 130 with respect to the groove portion 125 is inclined with respect to the extending direction of the tooth portion 121. Therefore, even if a force along the reference line L is applied to the core piece 120P, the connection member 130 is not easily pulled out from the groove portion 125. That is, according to the present modification, the connection member 130 is not easily separated from the core piece 120P, and the stability of the connection of the core piece 120P is improved. In the present modification, the angle α is about 5 °.

In addition, the connecting member 130 is sandwiched by the pair of opposing surfaces 125a in the groove portion 125 from both circumferential sides. By laminating the electromagnetic steel sheets of the connecting member 130 in the radial direction, the reaction force received by the connecting member 130 from the opposing surface 125a can be set to a direction intersecting the laminating direction of the electromagnetic steel sheets, and separation of the laminated electromagnetic steel sheets can be suppressed. In addition, the connection members 130 may be stacked in the circumferential direction. In this case, the connecting member 130 receives a force in a direction in which the stacked magnetic steel sheets are brought into close contact with each other, and suppresses separation of the magnetic steel sheets from each other.

As shown by the two-dot chain line in fig. 9, the cylindrical portion 81a of the stator holder 8 is disposed radially inward of the connecting member 130 of the present modification. The outer peripheral surface of the cylindrical portion 81a contacts the connecting member 130 from the radially inner side. The tube 81a restricts the movement of the connecting member 130 radially inward, and suppresses the connecting member 130 from coming off the coupling portion 122 of the core piece 120P. Thereby, the stator holder 8 suppresses the release of the connection between the plurality of core segments 120P.

Further, the outer peripheral surface of the cylindrical portion 81a applies a radially outward force to the coupling portion 122 in the radial direction via the connecting member 130. When the tube 81a applies a radially outward force to the coupling portion 122, the first end surface 122Aa is pressed against the second end surface 122Ab of the adjacent core piece 120P, and the fourth end surface 122Bb is pressed against the third end surface 122Ba of the adjacent core piece 120P. This improves the coupling strength and rigidity of stator core 120.

Although the embodiments and the modifications of the present invention have been described above, the respective configurations and combinations thereof are examples, and additions, omissions, substitutions, and other modifications of the configurations can be made without departing from the scope of the present invention. In addition, the present invention is not limited by the embodiments.

Description of the symbols

A motor; a stator; a rotor; a stator holder; 20. a stator core; 20P, 120P. 21. A tooth portion; 22. a connection ofA section; 22a, 122Aa... first end face (end face); 22b, 122Ab... second end face (end face); 23. a convex portion; 24. a recess; a first raised strip portion; a second raised strip portion; 29. a through hole (bore portion); 30. a connecting member; a main body portion; a clamping portion; a coil; a first retainer member; a barrel portion 81a, 86a.. section; a bottom plate portion 81b, 86 b.; 82. a protrusion; a first fixing hole (fixing hole); 85.. a fixation boss; a rivet; 86.. a second retainer member; 90.. a clamp; a retention projection; a pin; 122Ba... third end face (end face); 122Bb... fourth end face (end face); a first arm portion; a second arm portion; a recessed portion; an opposite face; j. central axis; l.. a reference line; an angle;

.., a second configuration angle;

.., a first configuration angle.

Claims (10)

1. A stator for an outer rotor type motor, comprising:

a stator core having a plurality of teeth arranged in a circumferential direction with respect to a central axis and extending in a radial direction;

coils wound around the plurality of teeth, respectively; and

a stator holder that holds the stator core,

the stator core has a plurality of core pieces having the tooth portions and a coupling portion located closer to the central axis than the tooth portions,

the stator holder has a first holder member and a second holder member that are opposed to each other in the axial direction and sandwich the stator core from both axial sides,

the connecting part is provided with a through hole which penetrates along the axial direction,

at least one of the first holder member and the second holder member has a plurality of protrusions that are inserted into the through holes of the plurality of core pieces, respectively.

2. The stator of claim 1,

the first holder member and the second holder member have bottom plate portions located radially inward of the stator core and extending along a plane orthogonal to the central axis,

the bottom plate portion of the first holder member and the bottom plate portion of the second holder member are in contact with each other in the axial direction and fixed to each other.

3. The stator of claim 2,

a fixing hole penetrating in an axial direction is provided in the bottom plate portion of the first holder member,

a fixing protrusion protruding toward the first holder member and inserted into the fixing hole is provided on the bottom plate portion of the second holder member,

the front end of the fixed convex part is provided with a riveting part,

the caulking portion and the bottom plate portion of the second holder member sandwich the bottom plate portion of the first holder member.

4. The stator of any one of claims 1 to 3,

the stator core has a plurality of connecting members that connect the coupling portions that are adjacent in the circumferential direction to each other, the connecting members being located radially inward with respect to the coupling portions,

at least one of the first holder member and the second holder member has a cylindrical portion located radially inside the plurality of core pieces and extending in an axial direction,

the outer peripheral surface of the cylindrical portion contacts the connecting member from a radially inner side.

5. The stator of any one of claims 1 to 4,

the coupling portion has a pair of end surfaces facing opposite sides in a circumferential direction,

the pair of end faces extend radially inward and incline to one side in the circumferential direction as facing radially inward,

the end surfaces of the coupling portions adjacent in the circumferential direction are respectively in contact with each other,

at least one of the first holder member and the second holder member has a cylindrical portion located radially inside the plurality of core pieces and extending in an axial direction,

the outer peripheral surface of the cylindrical portion exerts a force directed radially outward on the coupling portion.

6. The stator of any one of claims 1 to 5,

the coupling portion has a first arm portion and a second arm portion arranged in an axial direction,

the first arm portion has a pair of end surfaces facing opposite sides to each other in the circumferential direction,

the pair of end surfaces of the first arm portion extend radially inward and are inclined to one side in the circumferential direction as they extend radially inward,

the second arm portion has a pair of end surfaces facing opposite sides to each other in the circumferential direction,

the pair of end surfaces of the second arm portion extend radially inward and are inclined toward the other circumferential side as they go radially inward,

in the circumferentially adjacent joint portions, the end surfaces of the first arm portions are in contact with each other, and the end surfaces of the second arm portions are in contact with each other.

7. The stator of claim 6,

the first arm portion extends radially inward,

the second arm portion extends radially inward,

the direction in which the first arm portion extends radially inward is circumferentially displaced from the direction in which the second arm portion extends radially inward,

groove portions extending in the axial direction and opening to the radially inner side are provided at radially inner end portions of the first arm portion and the second arm portion, respectively,

in a pair of the core pieces adjacent in the circumferential direction, the first arm portion of one of the core pieces and the second arm portion of the other of the core pieces overlap each other when viewed in the axial direction, the respective groove portions are connected to each other in the axial direction,

the stator core is provided with a connecting component which is in a rod shape extending along the axial direction and is embedded in the groove parts connected along the axial direction.

8. The stator of claim 7,

the groove portion has a pair of opposing faces opposing each other in the circumferential direction,

the pair of opposing faces are inclined with respect to the reference line passing through the center of the tooth portion as viewed in the axial direction.

9. The stator of claim 7 or 8,

the connecting member is composed of electromagnetic steel sheets laminated in the radial direction.

10. A motor, comprising:

a stator according to any one of claims 1 to 9; and

a rotor surrounding the stator from a radially outer side and rotating about the central axis.

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