CN118572914A - Motor with a motor housing - Google Patents

Abstract

The motor is provided with: a rotor rotating about a rotation axis; and a stator located radially outward relative to the rotor. The stator has a stator core in which a plurality of unit cores are annularly arranged, and each of the plurality of unit cores has: teeth; and a core back extending circumferentially radially outward relative to the teeth. Any one of the plurality of unit cores further has a first protrusion part which partially protrudes radially outward from the outer peripheral surface of the radially outer side of the core back and extends in the circumferential direction from the circumferential direction one end portion to the circumferential direction other end portion of the core back.

Description

Motor with a motor housing

Technical Field

The present invention relates to a motor.

Background

Conventionally, it has been known to use an inner rotor type motor as a small driving source. In the inner rotor type motor, a rotor is disposed radially inward of a stator (see, for example, patent document 1).

In the motor described in patent document 1, the stator includes a stator core block arranged in an annular shape and an annular connecting yoke. The stator core block has: laminating the stator chips to form laminated stator cores; slot insulators provided to the laminated stator cores; and an exciting coil wound around the upper side of the slot insulator. The stator core piece has a tooth portion, a yoke portion, and a tooth tip enlarged portion, and is provided with a tenon (dovetail) protruding toward the outer periphery of the yoke portion. In the motor described in patent document 1, a tenon provided on the outer periphery of a yoke portion is coupled to a coupling yoke, thereby forming a strong coupling structure.

Prior art literature

Patent literature

Patent document 1: japanese patent application laid-open No. 2018-7413

Disclosure of Invention

Technical problem to be solved by the invention

However, in the case of downsizing the motor of patent document 1, if the radial direction of the yoke portion is shortened, the rigidity of the stator core is lowered, and noise may be generated by driving the motor.

The present invention has been made in view of the above-described problems, and an object thereof is to provide a motor in which rigidity of a stator core is improved.

Technical proposal adopted for solving the technical problems

An exemplary motor of the present invention includes: a rotor that rotates around a central axis; and a stator located radially outward relative to the rotor. The stator has a stator core in which a plurality of unit cores are annularly arranged. Each of the plurality of unit cores has: teeth; and a core back extending circumferentially radially outward relative to the teeth. Any one of the plurality of unit cores further has a first protrusion part which partially protrudes radially outward from an outer peripheral surface of the radially outer side of the core back and extends in the circumferential direction from a circumferential one-side end portion to a circumferential other-side end portion of the core back.

Effects of the invention

According to the exemplary present invention, a motor in which rigidity of a stator core is improved can be provided.

Drawings

Fig. 1 is a sectional view showing the structure of a motor according to an embodiment of the present invention.

Fig. 2 is an exploded perspective view of a motor according to an embodiment of the present invention.

Fig. 3A is a perspective view of a stator core of a motor according to an embodiment of the present invention.

Fig. 3B is a plan view showing a stator core of a motor according to an embodiment of the present invention.

Fig. 4A is a perspective view of a unit core of a motor according to an embodiment of the present invention.

Fig. 4B is a plan view showing a unit core of a motor according to an embodiment of the present invention.

Fig. 5A is an exploded top view of a stator core of a motor according to an embodiment of the present invention.

Fig. 5B is an expanded view of a stator core of a motor according to an embodiment of the present invention.

Fig. 6A is an exploded perspective view showing a positional relationship between a stator core and a first housing of a motor according to an embodiment of the present invention.

Fig. 6B is an exploded perspective view showing a positional relationship of a stator core and a second housing of the motor according to an embodiment of the present invention.

Fig. 7A is a side view of a motor according to an embodiment of the present invention.

Fig. 7B is a view of fig. 7A, in which the contents other than the first and second cases are omitted.

Fig. 7C is a cross-sectional view taken along line VIIC-VIIC of fig. 7A.

Fig. 8 is a perspective view of a part of a rotor of a motor according to an embodiment of the present invention, which is enlarged and shown.

(Symbol description)

10 Motor

100 Rotor

200 Stator

210 Stator core

210U unit core

211 Tooth

212 Core back

213 First protrusion

214 Second protrusion

Detailed Description

Exemplary embodiments of the present invention are described below with reference to the accompanying drawings. The same or corresponding portions in the drawings are denoted by the same reference numerals, and description thereof will not be repeated.

In the present specification, for convenience, the direction of the rotation axis AX (see fig. 1) of the motor may be described as the up-down direction. In the figure, for ease of understanding, the X-axis, Y-axis, and Z-axis of a three-dimensional rectangular coordinate system are appropriately described. The positive direction of the Z axis indicates the upward direction, and the negative direction of the Z axis indicates the downward direction. However, the vertical direction, the upward direction, and the downward direction are determined for convenience of explanation, and do not need to coincide with the vertical direction. The vertical direction is defined only for convenience of explanation, and the orientation at the time of use and assembly of the motor of the present invention is not limited. The direction parallel to the rotation axis AX of the motor is simply referred to as "axial direction AD", and the radial direction and the circumferential direction around the rotation axis AX of the motor are simply referred to as "radial direction RD" and "circumferential direction CD". The term "planar view" means that the object is viewed from the axial direction AD. In addition, the term "parallel direction" in the present specification includes a substantially parallel direction.

First, a motor 10 according to an embodiment of the present invention will be described with reference to fig. 1. Fig. 1 is a sectional view showing the construction of a motor 10 according to an embodiment of the present invention.

As shown in fig. 1, the motor 10 includes a bearing 11, a shaft 12, a rotor 100, a stator 200, and a housing 300. At least a part of the bearing 11, the shaft 12, the rotor 100, and the stator 200 is housed in the housing 300.

The rotor 100 is disposed around a rotation axis AX extending in the up-down direction. Here, the motor 10 is of an inner rotor type. The rotor 100 rotates about the rotation axis AX. The rotor 100 is disposed radially inward of the stator 200.

The rotor 100 has a rotor core 110 and a magnet 120. The magnet 120 is, for example, a permanent magnet. For example, the rotor 100 may have one magnet 120 in a substantially annular shape, or may have a plurality of magnets 120 arranged in the circumferential direction CD. The "substantially annular" is, for example, "substantially annular". For example, the number of poles of the magnet 120 is "fourteen". However, the number of poles of the magnet 120 is not limited thereto.

The rotor core 110 is made of, for example, laminated steel sheets (an example of a laminate (lamination)) in which electromagnetic steel sheets are laminated in the axial direction AD. The rotor core 110 may have a substantially annular core main body 110a and a plurality of projections 110b. The "substantially annular" is, for example, "substantially annular". Details of the convex portion 110b are described below with reference to fig. 8. The plurality of magnets 120 are arranged radially outward of the rotor core 110. In the present embodiment, the motor 10 is an SPM (Surface PERMANENT MAGNET: surface permanent magnet) motor. However, the rotor 100 may be a spoke (spoke) type rotor. The motor 10 may be an IPM (Interior PERMANENT MAGNET: interior permanent magnet) motor.

The bearing 11 rotatably supports the shaft 12. The bearing 11 is, for example, a rolling bearing.

The shaft 12 is disposed centering on the rotation axis AX. The shaft 12 is generally cylindrical. Shaft 12 is fixed to rotor core 110. Therefore, the shaft 12 rotates together with the rotor 100 about the rotation axis AX.

The housing 300 has a first housing 310 and a second housing 320. The first housing 310 is disposed on one axial side (-Z direction) of the motor 10. The first housing 310 covers one side (-Z direction) of the stator 200 in the axial direction.

The second housing 320 is disposed on the other axial side (+z direction) of the motor 10. The second housing 320 covers the other axial side (+z direction) of the stator 200.

In addition, a part of the stator core 210 is not covered by the first and second cases 310 and 320 but is exposed to the outer circumferential surface of the motor 10.

The rotor 100 and the stator 200 are disposed in a space formed by the first housing 310 and the second housing 320.

The stator 200 is arranged around a rotation axis AX extending in the up-down direction. The stator 200 is opposite to the magnet 120 in the radial direction RD. The stator 200 includes a stator core 210, an insulator 220, and a coil 230.

The stator core 210 is arranged around a rotation axis AX extending in the up-down direction. As an example, the stator core 210 is disposed around the central axis AX and has a substantially annular shape. The "substantially annular" is, for example, "substantially annular". The stator core 210 is formed of, for example, laminated steel sheets (an example of a laminate) in which thin electromagnetic steel sheets are laminated in the axial direction AD. The stator core 210 has a core back and teeth. Details of the stator core 210 are described below.

The insulator 220 covers at least a portion of the stator core 210. As an example, the insulator 220 is disposed around the central axis AX and has a substantially annular shape. The "substantially annular" is, for example, "substantially annular". Insulator 220 is an electrical insulator. The insulator 220 may be formed of a single member or may be formed of a plurality of different members. For example, the insulator 220 is a resin molded product in which the stator core 210 is embedded. The insulator 220 may be separately attached to the stator core 210.

The coil 230 is wound around the stator core 210 via the insulator 220. The coil 230 is a covered wire covered with a film. The raw material of the metal wire is copper, for example. However, instead of copper, the raw material of the metal wire may also be aluminum. The coating film covering the metal wire is, for example, an insulating resin. The raw material of the resin is, for example, enamel. The insulator 220 electrically insulates the stator core 210 from the coil 230. The insulator 220 is composed of an insulating material. The insulator 220 is made of, for example, a thermoplastic resin.

Here, the insulator 220 has an insulator 220a and an insulator 220b. Insulator 220a is located on one axial side (-Z direction) and insulator 220b is located on the other axial side (+z direction). The insulator 220a covers the circumferential side surface of the stator core 210, the other side surface, and the axial side (-Z direction) surface. The insulator 220b covers the side face of one side in the circumferential direction of the stator core 210, the side face of the other side, and the surface of the other side in the axial direction (+z direction).

The substrate SB has a substantially flat plate shape. The substrate SB is substantially orthogonal to the axial direction AD. The substrate SB is a printed circuit board on which wiring is printed, and various electronic components are mounted. The substrate SB is disposed substantially horizontally so as to face at least a part of the stator 200 and at least a part of the rotor 100 in the axial direction AD.

Next, a motor 10 according to an embodiment of the present invention will be described with reference to fig. 1 and 2. Fig. 2 is an exploded perspective view of a motor 10 according to an embodiment of the present invention.

As shown in fig. 2, the motor 10 includes a rotor 100, a stator 200, a first housing 310, and a second housing 320. The rotor 100 rotates about the rotation axis AX. The rotor 100 has a substantially cylindrical shape.

The stator 200 has a substantially cylindrical shape. The stator 200 is arranged around a rotation axis AX extending in the up-down direction. The rotor 100 is disposed radially inward of the stator 200. The stator 200 is opposite to the magnet 120 in the radial direction RD.

The first housing 310 covers the rotor 100 and the stator 200 from one side in the axial direction (-Z direction). The first housing 310 has a bottomed cylindrical shape having a bottom on one axial side (-Z direction).

The second case 320 covers the rotor 100 and the stator 200 from the other side in the axial direction (+z direction). The second housing 320 has a bottomed cylindrical shape having a bottom on the other axial side (+z direction).

The motor 10 further includes a fixing member 330. The fixing member 330 fixes the stator 200, the first housing 310, and the second housing 320.

For example, the fixing member 330 is a screw. The stator core 210 is provided with a through hole through which the fixing member 330 penetrates. In this case, the first housing 310 and the second housing 320 are provided with screw holes into which the fixing members 330 are fitted.

The fixing member 330 may be inserted from different directions with respect to the stator core 210 in the axial direction AD. The plurality of fixing members 330 may penetrate the first housing 310 and the stator core 210 from one axial side (-Z direction) toward the other axial side (+z direction) and be fitted into the second housing 320. Further, the other fixing members 330 may be inserted into the first housing 310 so as to penetrate the stator core 210 from the other axial side (+z direction) toward the one axial side (-Z direction).

The fixing member 330 includes a fixing member 330a, a fixing member 330b, and a fixing member 330c. The fixing members 330a, 330b, and 330c penetrate the first casing 310, the stator core 210, and are inserted into the second casing 320 from one axial side (-Z direction) toward the other axial side (+z direction).

Further, the fixing member 330 includes a fixing member 330s, a fixing member 330t, and a fixing member 330u. The fixing members 330s, 330t, and 330u penetrate the stator core 210 from the other axial side (+z direction) toward one axial side (-Z direction) and are fitted into the first housing 310.

Next, a stator core 210 of a motor 10 according to an embodiment of the present invention will be described with reference to fig. 1 to 3B. Fig. 3A is a perspective view of the stator core 210 of the motor 10 according to an embodiment of the present invention, and fig. 3B is a plan view of the stator core 210 of the motor 10 according to an embodiment of the present invention.

As shown in fig. 3A and 3B, the stator core 210 is constituted by a plurality of unit cores 210 u. The unit cores 210u are arranged in a ring shape. The unit core 210u is formed of laminated steel sheets (an example of a laminate) in which thin electromagnetic steel sheets are laminated in the axial direction AD. Here, the steel plates constituting one unit core 210u include steel plates having different shapes.

For example, the plurality of unit cores 210u include twelve unit cores (unit cores 210a to 210 l). In the present specification, the unit cores 210a to 210l are collectively referred to as a unit core 210u.

The unit core 210u has teeth 211 and a core back 212. The teeth 211 extend radially RD relative to the core back 212. The core back 212 extends from the radially outer side of the teeth 211 to the circumferential direction CD.

The unit core 210u also has a first protrusion 213. The first protrusion 213 partially protrudes radially outward from the radially outer peripheral surface of the core back 212. The first protrusion 213 extends from an end portion on one side in the circumferential direction to an end portion on the other side in the circumferential direction of the outer peripheral surface of the core back 212. Here, the plurality of unit cores 210u have the first protrusions 213, respectively.

Further, the unit core 210u also has a second protrusion 214. The second protrusion 214 partially protrudes radially outward from the radially outer peripheral surface of the core back 212. The second protrusion 214 extends from one end portion in the axial direction of the outer peripheral surface of the core back 212 to the other end portion in the axial direction. Here, the plurality of unit cores 210u have the second protrusions 214, respectively.

The unit core 210u further has a through hole 215 penetrating in the axial direction. The through hole 215 is located radially outward of the teeth 211.

The core backs 212 of the plurality of unit cores 210u are arranged along the circumferential direction CD. Specifically, the core back 212 is arranged in a substantially annular shape around the rotation axis AX. The "substantially annular" is, for example, "substantially polygonal annular" or "substantially circular annular". By "substantially polygonal ring-like" is meant that at least the outer edge is polygonal in shape. By "substantially annular" is meant that at least the outer edge is circular in shape. The core back 212 of the plurality of unit cores 210u may be formed of a single member or may be formed of a plurality of different members.

As described above, the first protrusion 213 of one unit core among the adjacent two unit cores 210u among the plurality of unit cores 210u is in contact with the first protrusion 213 of the other unit core. For example, the end of the first protrusion 213 of the unit core 210g on one side in the circumferential direction is in contact with the end of the first protrusion 213 of the unit core 210h on the other side in the circumferential direction.

As shown in fig. 2 to 3B, here, the stator core 210 has twelve unit cores 210u. Thus, the unit core 210u has twelve teeth 211 and twelve core backs 212. Twelve teeth 211 are equally spaced along the circumferential direction CD. Twelve core backs 212 are provided corresponding to twelve teeth 211, respectively. In addition, the number of unit cores 210u, the number of teeth 211, and the number of core backs 212 are not limited to "twelve".

As such, in the stator core 210, twelve core backs 212 are arranged along the circumferential direction CD. The twelve core backs 212 may be formed as a single member in a connected manner, or may be formed as different members.

The unit cores 210u constituting the stator core 210 may be divided cores that are in contact with the unit cores 210u divided individually from each other. The unit cores 210u constituting the stator core 210 may be connected to each other via a connecting portion.

Next, a stator core 210 of a motor 10 according to an embodiment of the present invention will be described with reference to fig. 1 to 4. Fig. 4A is a perspective view of the unit core 210u of the motor 10 according to an embodiment of the present invention, and fig. 4B is a plan view showing the unit core 210u of the motor 10 according to an embodiment of the present invention.

As shown in fig. 4A, the unit core 210u has teeth 211 and a core back 212. The teeth 211 extend radially RD relative to the core back 212. The core back 212 extends from the radially outer end of the tooth 211 in the circumferential direction CD. The core back 212 has a circular arc shape. The teeth 211 extend radially inward from the center of the inner peripheral surface of the core back 212.

The unit core 210u also has a first protrusion 213. The first protrusion 213 partially extends radially outward from the radially outer peripheral surface of the core back 212. The first protrusion 213 extends from one end to the other end in the circumferential direction of the core back 212.

Further, the unit core 210u also has a second protrusion 214. The second protrusion 214 partially extends radially outward from the radially outer peripheral surface of the core back 212. The second protrusion 214 extends from one axial end portion to the other axial end portion of the core back 212.

Here, in the unit core 210u, the first protrusion 213 and the second protrusion 214 intersect at the outer peripheral surface of the core back 212. Typically, the first protrusion 213 and the second protrusion 214 are orthogonal to the outer peripheral surface of the core back 212.

The length of the first protrusion 213 protruding radially outward from the outer peripheral surface of the core back 212 is substantially equal to the length of the second protrusion 214 protruding radially outward from the outer peripheral surface of the core back 212. Accordingly, the outer peripheral surface of the first protruding portion 213 and the outer peripheral surface of the second protruding portion 214 form a smooth curved surface. That is, since there is no portion protruding radially outward in the outer peripheral surface of the first protruding portion 213 and the outer peripheral surface of the second protruding portion 214, the motor 10 can be prevented from increasing in size.

In the unit core 210u, the first protrusion 213 and the second protrusion 214 are not provided in a part of the outer peripheral surface of the core back 212, and the outer peripheral surface of the core back 212 is exposed. In the present specification, a surface of the outer peripheral surface of the core back 212 where the first protrusion 213 and the second protrusion 214 are not provided is referred to as a reference surface 212s.

Here, the reference surface 212s is divided into four reference surfaces (reference surfaces 212s1, 212s2, 212s3, 212s 4) by the first protruding portion 213 and the second protruding portion 214. The reference surface 212s1 is located in a region on the other side (+z direction) and one side (-X direction) in the circumferential direction in the outer circumferential surface of the core back 212. The reference surface 212s2 is located in a region on one side in the axial direction (-Z direction) and one side in the circumferential direction (-X direction) of the outer peripheral surface of the core back 212. The reference surface 212s3 is located in a region on the other side in the axial direction (+z direction) and the other side in the circumferential direction (+x direction) of the outer peripheral surface of the core back 212. The reference surface 212s4 is located in a region on one side in the axial direction (-Z direction) and the other side in the circumferential direction (+x direction) of the outer peripheral surface of the core back 212.

In this case, the reference surface 212s1, the other axial side (+z direction) portion of the second protrusion 214, and the reference surface 212s3 are separated from the reference surface 212s2, the one axial side (-Z direction) portion of the second protrusion 214, and the reference surface 212s4 by the first protrusion 213. The reference surface 212s1, a portion of one circumferential side (-X direction) of the first protruding portion 213, and the reference surface 212s2 are separated from the reference surface 213s3, a portion of the other circumferential side (+x direction) of the first protruding portion 213, and the reference surface 212s4 by the second protruding portion 214. In this way, the first protruding portion 213 and the second protruding portion 214 are formed to intersect, and the first protruding portion 213 and the second protruding portion 214 are formed to protrude only partially from the outer peripheral surface of the core back 212, whereby the stator core 210 having improved rigidity can be made lightweight.

The unit core 210u is provided with a through hole 215. Typically, the through hole 215 is used for fixation by the fixation member 330. The through hole 215 penetrates the unit core 210u in the axial direction AD. Here, the through hole 215 and the second protrusion 214 are located on a straight line extending from the tooth 211 in the radial direction RD. Thus, even when the through hole 215 is provided, a decrease in motor performance due to magnetic flux leakage can be suppressed. Further, the portion through which the magnetic flux lines pass can be suppressed from becoming too thin, and therefore, the motor performance can be further suppressed from being degraded.

Further, the through-hole 215 is provided across the core back 212 and the second protrusion 214. This can suppress the unit core 210u from becoming longer in the radial direction RD even when the through-hole 215 is provided.

In the above description with reference to fig. 1 to 4B, the unit core 210u has the teeth 211, the core back 212, the first protruding portion 213, and the second protruding portion 214, but the present embodiment is not limited thereto. The unit core 210u may have the teeth 211, the core back 212, and the first protruding portion 213, and may not have the second protruding portion 214. In this case, the unit core 210u has the first protrusion 213 that partially protrudes radially outward from the outer peripheral surface of the radial outer side of the core back 212 and extends circumferentially from the circumferential one-side end portion to the circumferential other-side end portion of the core back 212, whereby the rigidity of the stator core 210 can be improved. However, it is preferable that the unit core 210u has the second protrusion 214 in addition to the teeth 211, the core back 212, and the first protrusion 213. This can further improve the rigidity of the stator core 210.

In the above description with reference to fig. 1 to 4B, the stator core 210 has twelve unit cores 210u of the same shape, but the present embodiment is not limited thereto. The unit cores 210u of the stator core 210 may not have the same shape. For example, at least one unit core 210u of the stator core 210 may have teeth 211, a core back 212, and a first protrusion 213. At least one unit core 210u of the stator core 210 may have a second protrusion 214 in addition to the teeth 211, the core back 212, and the first protrusion 213.

Thus, the motor 10 includes: a rotor 100 that rotates around a rotation axis AX; and a stator 200 located radially outward with respect to the rotor 100. The stator 200 includes a stator core 210 in which a plurality of unit cores 210u are annularly arranged. Each of the plurality of unit cores 210u has teeth 211 and a core back 212 extending circumferentially radially outward relative to the teeth 211. Any one of the plurality of unit cores 210u further has a first protrusion 213 that partially protrudes radially outward from the outer peripheral surface of the radially outer side of the core back 212 and extends circumferentially from one circumferential end portion to the other circumferential end portion of the core back 212.

The first protruding portion 213 protruding partially radially outward from the outer peripheral surface of the core back 212 extends from one circumferential side to the other circumferential side of the core back 212 in the circumferential direction CD, whereby the unit core 210u can be lengthened in the radial direction RD, and therefore the rigidity of the stator core 210 can be improved, and noise can be suppressed.

As described above, each of the plurality of unit cores 210u may have the first protrusion 213, and the first protrusion 213 of one unit core of the adjacent two unit cores 210u of the plurality of unit cores 210u may be in contact with the first protrusion 213 of the other unit core. Since the first protrusions 213 of the adjacent unit cores 210u are in contact, the rigidity of the stator core 210 can be improved, and noise can be suppressed.

Any one of the plurality of unit cores 210u further has a second protrusion 214 partially protruding radially outward from the outer peripheral surface of the radially outer side of the core back 212 and extending in the axial direction from one axial side of the core back 214 to the other axial side. Accordingly, since the first protruding portion 213 protruding in the circumferential direction and the second protruding portion 214 extending in the axial direction are provided on the outer peripheral surface of the core back 212, the radial length of the unit core can be ensured to be wide, and therefore, the rigidity of the stator core 210 can be improved, and noise can be suppressed.

In any one of the unit cores 210u, the first protruding portion 213 protrudes with respect to each of the reference surfaces 212s on one side in the axial direction and the other side in the axial direction of the outer peripheral surface of the core back 212. In any one of the unit cores 210u, the second protrusion 214 protrudes with respect to each of the reference surfaces on one side and the other side in the circumferential direction of the outer peripheral surface of the core back 212. The first protrusion 213 intersects the second protrusion 214. This can reduce the weight of the stator core 210 with increased rigidity.

Any one of the unit cores 210u is provided with a through hole 215 extending in the axial direction AD. The through hole 215 and the second protrusion 214 are located on a straight line extending from the tooth 211 in the radial direction RD. Therefore, even if the through-hole 215 is provided in the unit core 210u, the through-hole 215 and the second protrusion 214 are positioned on a straight line extending from the tooth 211 in the radial direction RD, so that a decrease in motor performance (efficiency, torque) due to magnetic flux leakage can be suppressed.

In any of the unit cores 210u, a through hole 215 extending in the axial direction AD is provided across the core back 212 and the second protrusion 214. The protruding portion can be reduced when the unit core 210u is provided with the through hole 215.

The motor 10 further includes: a first housing 310 covering the stator 200 from one side in the axial direction; a second housing 320 covering the stator 200 from the other axial side; and a fixing member 330 penetrating the through hole 215 to fix the stator 200 of the first case 310 and the second case 320. The fixing member 330 fixes the stator 200 and the first and second cases 310 and 320 covering the stator 200 from both sides in the axial direction, thereby easily assembling the motor 10.

The motor 10 further includes: a first housing 310 covering the stator 200 from one side in the axial direction; and a second housing 320 covering the stator 200 from the other side in the axial direction. The radially outer peripheral surfaces of the first and second cases 310 and 320 are located on the same plane or radially outer side with respect to the radially outer peripheral surface of the stator core 210. Thereby, the motor 10 along the radial direction RD can be reduced in size.

The motor 10 of the present embodiment is preferably used for a small-sized motor. For example, either one of the first housing 310 and the second housing 320 may be provided with a gear to serve as a carrier. The motor is preferably used as a motor for a bicycle with electric motor.

Next, a stator core 210 of a motor 10 according to an embodiment of the present invention will be described with reference to fig. 1 to 5A. Fig. 5A is an exploded top view of the stator core 210 of the motor 10 according to an embodiment of the present invention.

As shown in fig. 5A, the unit cores 210u constituting the stator core 210 are separate divided cores separated from each other. The unit cores 210u are each a single member.

When the stator core 210 is manufactured from the unit cores 210u, the side surface of one of the adjacent unit cores 210u on the circumferential side of the core back 212 is welded to the side surface of the other unit core 210u on the circumferential side of the core back 212. Thus, the stator core 210 in which two adjacent unit cores 210u are in contact can be manufactured.

In this way, in the stator core 210, each of the plurality of unit cores 210u is a split core that is split and contacted. Each of the plurality of unit cores 210u has a laminated structure in which a plurality of laminated bodies are laminated in the axial direction AD. The laminate is, for example, an electromagnetic steel sheet. That is, each unit core 210u is formed by stacking a plurality of laminated bodies, and by bringing adjacent unit cores 210u into contact with each other and forming the unit cores into a substantially annular shape, one stator core 210 can be easily assembled. For example, a plurality of laminated bodies are riveted to form the unit core 210 u. In this case, by manufacturing the unit cores 210u in a number that can be formed in a substantially annular shape, one stator core 210 can be easily assembled.

For example, the unit core 210u may have a laminated structure in which a plurality of different laminated bodies are laminated in the axial direction AD. In this case, for example, the unit core 210u may have a laminated structure in which a plurality of laminated bodies having different shapes are laminated in the axial direction AD. The unit core 210u may have a laminated structure in which a plurality of identical laminated bodies are laminated in the axial direction AD.

The stator core 210 shown in fig. 5A is composed of a unit core 210u as a split core, but the present embodiment is not limited thereto. In the stator core 210, a plurality of unit cores 210u may be connected to each other via a connecting portion.

Next, a stator core 210 of a motor 10 according to an embodiment of the present invention will be described with reference to fig. 1 to 5B. Fig. 5B is an expanded view of the stator core 210 of the motor 10 according to an embodiment of the present invention.

As shown in fig. 5B, the stator core 210 has: a plurality of unit cores 210u arranged in a straight line; and a connecting portion 216 connecting adjacent unit cores 210 u. In this case, the plurality of unit cores 210u are connected to each other via the connecting portion 216. Typically, the connecting portion 216 is formed by laminated steel plates constituting the unit cores 210 u.

Specifically, the connecting portion 216 connects one side surface of the core back 212 in the circumferential direction of one unit core 210u with the other side surface of the core back 212 in the circumferential direction of the other unit core 210u in the adjacent two unit cores 210 u.

The stator core 210 may be constituted by the unit cores 210u connected in this manner via the connecting portions 216. In this case, the stator core 210 is produced by welding the side surface of one of the adjacent two unit cores 210u on the circumferential side of the core back 212 with the side surface of the other of the adjacent two unit cores 210u on the circumferential side of the core back 212.

Next, the stator core 210 and the first housing 310 of the motor 10 according to the embodiment of the present invention will be described with reference to fig. 1 to 6A. Fig. 6A is an exploded perspective view showing a positional relationship of the stator core 210 and the first housing 310 of the motor 10 according to an embodiment of the present invention.

As shown in fig. 6A, the first housing 310 covers the stator 200 from one side in the axial direction (-Z direction). The first housing 310 is located at one side in the axial direction (-Z direction) with respect to the stator 200.

The first housing 310 has a first base portion 312, a first annular wall 314, and a plurality of first guide portions 316. The first base portion 312 has a substantially disk shape. The first body portion 312 is provided with holes and/or recesses as desired. The first annular wall 314 extends annularly from the outer edge of the first base portion 312 to the other axial side (+z direction). The first annular wall 314 has an end 314s on the other axial side (+z direction) of the first annular wall 314.

The plurality of first guide portions 316 partially protrude from the end portion 314s of the first annular wall 314 toward the other axial side (+z direction). The plurality of first guide portions 316 are arranged in the circumferential direction CD. The first guide portion 316 is located radially outward in the surface of the outer edge of the first base portion 312. For example, the plurality of first guide portions 316 are arranged at equal intervals in the circumferential direction CD. Here, the plurality of first guide portions 316 is twelve. However, the number of the first guide portions 316 is not limited to this, and may be changed according to the number of the unit cores 210 u.

The first base portion 312 and the first annular wall 314 are provided with screw holes 318 into which the fixing members 330 are inserted. The threaded bore 318 extends in the axial direction AD.

The stator core 210 is accommodated in the first housing 310. In this case, the first protruding portion 213 of the unit core 210u in the stator core 210 is opposed to the first guide portion 316 in the axial direction AD. Further, the second protrusion 214 is located between two adjacent first guide portions 316.

Next, the stator core 210 and the second housing 320 of the motor 10 according to the embodiment of the present invention will be described with reference to fig. 1 to 6B. Fig. 6B is an exploded perspective view showing a positional relationship of the stator core 210 and the second housing 320 of the motor 10 according to an embodiment of the present invention.

As shown in fig. 6B, the second housing 320 covers the stator 200 from the other side in the axial direction (+z direction). The second housing 320 is located on the other side (+z direction) in the axial direction with respect to the stator 200.

The second housing 320 has a second base portion 322, a second annular wall 324, and a plurality of second guide portions 326. The second base portion 322 has a substantially disk shape. The second base portion 322 is provided with holes and/or recesses as desired. The second annular wall 324 extends annularly from the outer edge of the second base portion 322 to one axial side (-Z direction). The second annular wall 324 has an end 324s on one axial side (-Z direction) of the second annular wall 324.

The plurality of second guide portions 326 partially protrude from the end 324s of the second annular wall 324 toward one axial side (-Z direction). The plurality of second guide portions 326 are arranged in the circumferential direction CD. The second guide 326 is located radially outward in the surface of the outer edge of the second base portion 322. For example, the plurality of second guide portions 326 are arranged at equal intervals in the circumferential direction CD. Here, the plurality of second guide portions 326 is twelve. However, the number of the second guide portions 326 is not limited thereto, and may be changed according to the number of the unit cores 210 u.

The second base portion 322 and the second annular wall 324 are provided with screw holes 328 into which the fixing members 330 are inserted. Threaded bore 328 extends in axial direction AD.

The stator core 210 is accommodated in the second housing 320. In this case, the first protruding portion 213 of the unit core 210u in the stator core 210 is opposed to the second guiding portion 326 in the axial direction AD. Further, the second protrusion 214 is located between two adjacent second guide portions 326.

Next, a motor 10 according to an embodiment of the present invention will be described with reference to fig. 1 to 7C. Fig. 7A is a side view of motor 10 according to one embodiment of the present invention. Fig. 7B is a view in which the contents other than the first case 310 and the second case 320 in fig. 7A are omitted. Fig. 7C is a cross-sectional view taken along line VIIC-VIIC of fig. 7A.

As shown in fig. 7A, the stator 200, the first housing 310, and the second housing 320 are located on the outer peripheral surface of the motor 10. The stator core 210 of the stator 200 is located between the first housing 310 and the second housing 320. In detail, the first and second protrusions 213 and 214 in the stator core 210 are exposed from the first and second cases 310 and 320. As a result, the heat dissipation performance of the stator core 210 can be improved.

In the first housing 310, an end 314s of the first annular wall 314 on the other axial side (+z direction) faces the second protrusion 214 with a gap therebetween in the axial direction AD. Further, both ends of the first guide portion 316 in the circumferential direction face the second protruding portion 214 with a gap therebetween in the circumferential direction CD. The other end portion (+z direction) of the first guide portion 316 in the axial direction faces the first protrusion 213 with a gap therebetween in the axial direction AD.

Similarly, in the second case 320, an end 324s of the second annular wall 324 on one axial side (-Z direction) faces the second protrusion 214 in the axial direction AD with a gap therebetween. The second guide 326 has both ends in the circumferential direction facing the second protrusion 214 with a gap therebetween in the circumferential direction CD. Further, an end portion of the second guide portion 326 on one axial side (-Z direction) is opposed to the first protruding portion 213 with a gap therebetween in the axial direction AD.

As can be understood from the outer peripheral surfaces of the motor 10 in the-X direction in fig. 7A, the radially outer peripheral surfaces of the first housing 310 and the second housing 320 are on the same plane with respect to the radially outer peripheral surface of the stator core 210. However, the radially outer peripheral surfaces of the first casing 310 and the second casing 320 may be located radially outward from the radially outer peripheral surface of the stator core 210.

As shown in fig. 7B, the first housing 310 has an annular first annular wall 314 and a plurality of first guide portions 316. The first annular wall 314 extends from the outer edge of the first base portion 312 to the other axial side (+z direction). The first guide portion 316 extends from an end 314s of the first annular wall 314 on the other axial side (+z direction) to the other axial side (+z direction). The plurality of first guide portions 316 are arranged in the circumferential direction CD.

As described above, the first annular wall 314 has the end 314s on the other axial side (+z direction) of the first annular wall 314. The end 314s has: an inner diameter portion 314s1 located radially inward of the first guide portion 316; and an outer diameter portion 314s2 located between adjacent first guide portions 316. The inner diameter portion 314s1 extends in the circumferential direction CD. The outer diameter portion 314s2 is recessed relative to the inner diameter portion 314s 1. Therefore, the outer diameter portion 314s2 is located on one axial side (-Z direction) with respect to the inner diameter portion 314s1 along the axial direction AD.

Similarly, the second housing 320 has an annular second annular wall 324 and a plurality of second guide portions 326. The second annular wall 324 extends from the outer edge of the second base portion 322 to one axial side (-Z direction). The second guide 326 extends from an end of the second annular wall 324 on one axial side (-Z direction) to one axial side (-Z direction). The plurality of second guide portions 326 are arranged in the circumferential direction CD.

In detail, the second annular wall 324 has an end 324s on one axial side (-Z direction) of the second annular wall 324. The end 324s has: an inner diameter portion 324s1 located radially inward of the second guide portion 326; and an outer diameter portion 324s2 located between adjacent second guide portions 326. The inner diameter portion 324s1 extends in the circumferential direction CD. The outer diameter portion 324s2 is recessed relative to the inner diameter portion 324s 1. Therefore, the outer diameter portion 324s2 is located on the other axial side (+z direction) with respect to the inner diameter portion 324s1 along the axial direction AD.

As shown in fig. 7C, in the stator core 210, the first protrusion 213 and the second protrusion 214 are not in contact with the first housing 310, and the core back 212 is in contact with the first housing 310. Specifically, the surface of the core back 212 on one axial side (-Z direction) is not in contact with the outer diameter portion 314s2 of the first housing 310, but is in contact with the inner diameter portion 314s 1.

Similarly, in the stator core 210, the first protrusion 213 and the second protrusion 214 are not in contact with the second housing 320, while the core back 212 is in contact with the second housing 320. Specifically, the other axial side (+z direction) surface of the core back 212 is not in contact with the outer diameter portion 324s2 of the second housing 320, and is in contact with the inner diameter portion 324s 1.

Thus, the motor 10 further includes: a first housing 310 covering the stator 200 from one side in the axial direction; and a second housing 320 covering the stator 200 from the other side in the axial direction. The first housing 310 has: a first base portion 312; an annular first annular wall 314 extending from an outer edge of the first base portion 312 toward the other axial side (+z direction); and a plurality of first guide portions 316 arranged in the circumferential direction, which extend from an end portion 314s of the first annular wall 314 on the other axial side (+z direction) to the other axial side (+z direction). The first guide portion 316 is opposite to the second projection 214 in the circumferential direction CD with a gap therebetween at both ends in the circumferential direction. The surface of one axial side (-Z direction) of the stator core 210 is in contact with the end 314s of the other axial side (+z direction) of the first annular wall 314. This enables the stator core 210 to be positioned with high accuracy with respect to the first housing 310.

The motor 10 further includes: a first housing 310 covering the stator 200 from one side in the axial direction (-Z direction); and a second housing 320 covering the stator 200 from the other side in the axial direction (+z direction). The second housing 320 has: a second base portion 322; an annular second annular wall 324 extending from an outer edge of the second base portion 322 toward one axial side (-Z direction); and a plurality of second guide portions 326 arranged in the circumferential direction CD, which extend from an end portion 324s of the second annular wall 324 on one axial side (-Z direction) to one axial side (-Z direction). The second guide 326 has both ends in the circumferential direction facing the second protrusion 214 with a gap therebetween in the circumferential direction CD. The surface of the other axial side (+z direction) of the stator core 210 is in contact with the end 324s of one axial side (-Z direction) of the first annular wall 324. This enables the stator core 210 to be positioned with high accuracy with respect to the second housing 320.

Next, with reference to fig. 8, a description will be given of the convex portion 110b of the rotor core 110 shown in fig. 1. Fig. 8 is an enlarged and illustrated perspective view of a part of a rotor 100 of a motor 10 according to an embodiment of the present invention. As shown in fig. 8, the convex portion 110b protrudes radially outward from the radially outer peripheral surface of the core main body 110 a. The plurality of protruding portions 110b are arranged at intervals in the circumferential direction CD. The magnet 120 is disposed between the convex portion 110b and the convex portion 110b adjacent in the circumferential direction CD. By providing the rotor core 110 with the convex portion 110b, positioning of the magnet 120 is facilitated, and the work of applying the adhesive to the surface of the rotor core 110 is facilitated. Further, two or more protrusions 110b are arranged at respective positions P along the circumferential direction CD of the rotor core 110 with an interval in the axial direction AD. In the example of fig. 8, three protruding portions 110b are arranged at intervals in the axial direction AD. However, the number of the convex portions 110b at each position P is not limited to three.

In more detail, each of the plurality of protrusions 110b has one or more tabs 111. Tab 111 is part of a laminate. In the present embodiment, each of the plurality of convex portions 110b has a plurality of tabs 111. In the example of fig. 8, the boss 110b has three or four tabs 111. However, the number of the tabs 111 in each of the convex portions 110b is not limited to three and four. In each of the plurality of convex portions 110b, the plurality of tabs 111 are arranged along the axial direction AD. The protruding pieces 111 protrude radially outward from the radially outer peripheral surface of the core main body 110 a.

For example, one convex portion 110b may be arranged at each position P along the circumferential direction CD of the rotor core 110. In this case, for example, the convex portion 110b extends from one axial end portion to the other axial end portion of the core main body 110 a. In this example, the plurality of fins 111 are arranged in the axial direction AD from one axial end portion to the other axial end portion of the core body 110a in the protruding portion 110b.

The embodiments of the present invention are described above with reference to the drawings (fig. 1 to 8). However, the present invention is not limited to the above-described embodiments, and can be implemented in various modes within a scope not departing from the gist thereof. For ease of understanding, the drawings schematically show the main body of each structural element, and for convenience of drawing, the thickness, length, number, and the like of each structural element shown in the drawings are different from those in practice. The materials, shapes, sizes, and the like of the respective constituent elements shown in the above embodiments are not particularly limited, and various modifications can be made without substantially departing from the effects of the present invention.

In addition, the present technology can employ the following structure.

(1) A motor, the motor comprising: a rotor that rotates around a central axis; and

A stator located radially outward with respect to the rotor,

In the case of the motor in question,

The stator has a stator core in which a plurality of unit cores are annularly arranged,

Each of the plurality of unit cores has:

Teeth; and

A core back extending circumferentially radially outward relative to the teeth,

Any one of the plurality of unit cores further has:

And a first protrusion part which partially protrudes radially outward from an outer peripheral surface of the core back in a radial direction, and which extends from one end part to the other end part in the circumferential direction.

(2) In the motor of (1), each of the plurality of unit cores has the first protruding portion,

The first protrusion of one of the adjacent two unit cores is in contact with the first protrusion of the other unit core.

(3) In the motor described in (1) or (2), in the stator core, each of a plurality of the unit cores is a split core split and contacted,

Each of the plurality of unit cores has a laminated structure in which a plurality of laminated bodies are laminated in the axial direction.

(4) In the motor according to (3), any one of the plurality of unit cores further includes a second protrusion that partially protrudes radially outward from an outer peripheral surface of the core back in a radial direction, and extends in an axial direction from one axial side to the other axial side of the core back.

(5) In the motor according to (4), in any one of the unit cores, the first protrusion protrudes with respect to each of the reference surfaces on one side in the axial direction and the other side in the axial direction of the outer peripheral surface of the core back,

In any one of the unit cores, the second protrusion protrudes with respect to each of the reference surfaces on one side and the other side in the circumferential direction of the outer peripheral surface of the core back,

The first protrusion intersects the second protrusion.

(6) In the motor according to (4), the unit core is provided with a through hole extending in the axial direction, and the through hole and the second protrusion are located on a straight line extending in the radial direction from the tooth.

(7) In the motor according to (4), in any one of the unit cores, a through hole extending in the axial direction is provided so as to span the core back and the second protrusion.

(8) The motor according to (6) or (7), further comprising: a first housing covering the stator from one axial side;

a second housing covering the stator from the other axial side; and

And a fixing member that fixes the first housing, the second housing, and the stator so as to penetrate the penetration hole.

(9) The motor according to (1) or (2), further comprising: a first housing covering the stator from one axial side; and

A second housing covering the stator from the other side in the axial direction,

The radially outer peripheral surfaces of the first and second housings are on the same plane or radially outer side with respect to the radially outer peripheral surface of the stator core.

(10) The motor according to (4), further comprising: a first housing covering the stator from one axial side; and

A second housing covering the stator from the other side in the axial direction,

The first housing has:

a first base portion;

An annular first annular wall extending from an outer edge of the first base portion to the other side in the axial direction; and

A plurality of first guide portions arranged in a circumferential direction, the plurality of first guide portions extending from an end portion of the first annular wall on the other axial side toward the other axial side,

The first guide portion is circumferentially opposite to the second protruding portion with a gap therebetween at both circumferential ends,

A surface of one axial side of the stator core is in contact with an end of the other axial side of the first annular wall.

(11) The motor according to (4), further comprising: a first housing covering the stator from one axial side; and

A second housing covering the stator from the other side in the axial direction,

The second housing has:

A second base portion;

An annular second annular wall extending from an outer edge of the second base portion to one side in an axial direction; and

A plurality of second guide portions arranged in the circumferential direction, the plurality of second guide portions extending from an end portion of one axial side of the second annular wall to one axial side,

The second guide portion is circumferentially opposite to the second protruding portion with a gap interposed therebetween,

The other axial side surface of the stator core is in contact with the one axial side end of the second annular wall.

Claims (11)

1. A motor, the motor comprising:

A rotor that rotates around a central axis; and

A stator located radially outward with respect to the rotor,

It is characterized in that the method comprises the steps of,

The stator has a stator core in which a plurality of unit cores are annularly arranged,

Each of the plurality of unit cores has:

Teeth; and

A core back extending circumferentially radially outward relative to the teeth,

Any one of the plurality of unit cores further has:

And a first protrusion part which partially protrudes radially outward from an outer peripheral surface of the core back in a radial direction, and which extends from one end part to the other end part in the circumferential direction.

2. The motor according to claim 1, wherein,

Each of the plurality of unit cores has the first protrusion,

The first protrusion of one of the adjacent two unit cores is in contact with the first protrusion of the other unit core.

3. A motor according to claim 1 or 2, wherein,

In the stator core, each of the plurality of unit cores is a divided core divided and contacted,

Each of the plurality of unit cores has a laminated structure in which a plurality of laminated bodies are laminated in the axial direction.

4. The motor according to claim 1, wherein,

Any one of the plurality of unit cores further has a second protrusion part which partially protrudes radially outward from an outer peripheral surface of the radially outer side of the core back and extends in the axial direction from one axial side of the core back to the other axial side.

5. The motor according to claim 4, wherein,

In any one of the unit cores, the first protrusion protrudes from each of the reference surfaces on one side in the axial direction and the other side in the axial direction of the outer peripheral surface of the core back,

In any one of the unit cores, the second protrusion protrudes with respect to each of the reference surfaces on one side and the other side in the circumferential direction of the outer peripheral surface of the core back,

The first protrusion intersects the second protrusion.

6. The motor according to claim 4, wherein,

Any unit core is provided with a through hole extending along the axial direction,

The through hole and the second protrusion are located on a straight line extending radially from the tooth.

7. The motor according to claim 4, wherein,

In the unit cores, a through hole extending in the axial direction is provided across the core back and the second protrusion.

8. The motor according to claim 6 or 7, characterized by further comprising:

A first housing covering the stator from one axial side;

a second housing covering the stator from the other axial side; and

And a fixing member that fixes the first housing, the second housing, and the stator so as to penetrate the penetration hole.

9. The motor according to claim 1 or 2, characterized by further comprising:

a first housing covering the stator from one axial side; and

A second housing covering the stator from the other side in the axial direction,

The radially outer peripheral surfaces of the first and second housings are on the same plane or radially outer side with respect to the radially outer peripheral surface of the stator core.

10. The motor according to claim 4, characterized by further comprising:

a first housing covering the stator from one axial side; and

A second housing covering the stator from the other side in the axial direction,

The first housing has:

a first base portion;

An annular first annular wall extending from an outer edge of the first base portion to the other side in the axial direction; and

A plurality of first guide portions arranged in a circumferential direction, the plurality of first guide portions extending from an end portion of the first annular wall on the other axial side toward the other axial side,

The first guide portion is circumferentially opposite to the second protruding portion with a gap therebetween at both circumferential ends,

A surface of one axial side of the stator core is in contact with an end of the other axial side of the first annular wall.

11. The motor according to claim 4, characterized by further comprising:

a first housing covering the stator from one axial side; and

A second housing covering the stator from the other side in the axial direction,

The second housing has:

A second base portion;

An annular second annular wall extending from an outer edge of the second base portion to one side in an axial direction; and

A plurality of second guide portions arranged in the circumferential direction, the plurality of second guide portions extending from an end portion of one axial side of the second annular wall to one axial side,

The second guide portion is circumferentially opposite to the second protruding portion with a gap interposed therebetween,

The other axial side surface of the stator core is in contact with the one axial side end of the second annular wall.