Motor and electric vehicle

Abstract

To provide a motor capable of performing exchange with a new rim part without disassembling a motor part, and an electric vehicle.SOLUTION: A motor 10 comprises a motor part and a rim part 400. The motor part includes a stationary part 50 and a rotary part 100 which is rotated with respect to the stationary part. The rim part supports a tire. The stationary part includes a fixture shaft and a motor stator 200 which is positioned radially outside with respect to the fixture shaft. The rotary part includes: a magnet which is opposed to the motor stator radially outside; a yoke 110 which is fixed on the radially outside face of the magnet; and a cover 260 to which the yoke is fixed and which is disposed rotatably with respect to the fixture shaft. The rim part is connected to at least one of the yoke and the cover by a fastening member.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a motor and an electric vehicle.

Background Art

[0002] Conventionally, an electric two-wheeled vehicle equipped with an in-wheel motor directly connected to a wheel and driven has been known.

[0003] Also, a wheel including a rim portion, a hub portion, a spoke portion, a stator core and a coil, a ferrite magnet, and a back yoke portion is known (see, for example, Patent Document 1). The rim portion supports a tire. The hub portion is provided inside the rim portion in the radial direction of the wheel and rotates about the rotation axis of the wheel. The spoke portion connects the rim portion to the hub portion. The stator core and the coil are provided inside the spoke connection portion of the hub portion to which the spoke portion is connected in the radial direction of the wheel and around the rotation axis of the wheel. The ferrite magnet is provided inside the spoke connection portion of the hub portion in the radial direction of the wheel and outside the stator core, faces the stator core, and rotates together with the hub portion, the spoke portion, and the rim portion about the rotation axis of the wheel. The back yoke portion is provided inside the spoke connection portion of the hub portion in the radial direction of the wheel and outside the ferrite magnet and supports the ferrite magnet. Further, the back yoke portion is integrally formed with the hub portion by being cast into the hub portion.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the wheel described in Patent Document 1, when replacing the attached rim portion with a new rim portion, since the rim portion is connected to the motor portion such as the spoke portion, the hub portion, and the back yoke portion, it is necessary to replace it with a motor portion including the new rim portion, which is costly. Alternatively, when replacing only the new rim portion, it took time to disassemble the attached motor portion.

[0006] The present disclosure has been made in view of the above problems, and an object thereof is to provide a motor and an electric vehicle capable of replacing the attached rim portion with a new rim portion without disassembling the motor portion.

Means for Solving the Problems

[0007] An exemplary motor according to the present disclosure includes a motor portion and a rim portion. The motor portion includes a fixed portion and a rotating portion that rotates with respect to the fixed portion. The rim portion supports a tire. The fixed portion includes a fixed shaft and a motor stator located radially outside the fixed shaft. The rotating portion includes a magnet facing radially outside the motor stator, a yoke fixed to the radially outer surface of the magnet, and a cover to which the yoke is fixed and which is arranged to be rotatable with respect to the fixed shaft. The rim portion is connected to at least one of the yoke and the cover by a fastening member.

[0008] An exemplary electric vehicle according to the present disclosure includes the motor described above and a wheel, and the motor is attached to the wheel.

Effects of the Invention

[0009] According to an exemplary aspect of the present disclosure, it is possible to provide a motor capable of replacing the attached rim portion with a new rim portion without disassembling the motor portion.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0011] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and the description will not be repeated.

[0012] In this specification, for convenience, the direction of the rotation axis AX (see FIG. 1) of the motor may be described as the horizontal direction. In the drawings, for ease of understanding, the X-axis, Y-axis, and Z-axis of the three-dimensional orthogonal coordinate system are appropriately shown. In one example, 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 up-down direction, upward direction, and downward direction are defined for convenience of explanation and do not necessarily coincide with the vertical direction. Also, the up-down direction is defined only for convenience of explanation and does not limit the orientation of the motor according to the present invention during use and assembly. Further, the direction parallel to the rotation axis AX of the motor is simply described as the "axial direction AD", and the radial direction and circumferential direction centered on the rotation axis AX of the motor are simply described as the "radial direction RD" and "circumferential direction CD", respectively. Note that in this specification, the "parallel direction" includes a substantially parallel direction.

[0013] In this specification, the rotation axis AX of the motor may coincide with the rotation axis of the rotor, but the rotation axis AX of the motor does not necessarily have to coincide with the rotation axis of the rotor. When the rotation axis AX of the motor does not coincide with the rotation axis of the rotor, the rotor may rotate about a virtual central axis different from the rotation axis AX of the motor.

[0014] In this specification, the direction along the rotation axis AX of the motor or the rotation axis of the rotor may be described as the axial direction. Therefore, in this specification, the axial direction indicates the direction along the rotation axis AX that is the center of rotation of the motor or the rotation axis that is the center of rotation of the rotor.

[0015] (First Embodiment) First, with reference to FIG. 1, the motor 10 according to the first embodiment of the present disclosure will be described. FIG. 1 is a perspective view showing the motor 10 of the first embodiment of the present disclosure. As shown in FIG. 1, the motor 10 includes a motor unit 20 and a rim portion 400.

[0016] The motor 10 is attached to the wheel of a four-wheeled vehicle or a two-wheeled vehicle as an example. Typically, the motor 10 is used as an in-wheel motor attached to the axle of a four-wheeled vehicle or a two-wheeled vehicle.

[0017] The motor unit 20 includes a rotor 100 and a fixed portion 300. The rotor 100 is an example of a "rotating portion".

[0018] The rim portion 400 supports a tire (not shown). The rim portion 400 surrounds the outer periphery of the motor unit 20.

[0019] Next, with reference to FIGS. 1 and 2, the motor unit 20 of the first embodiment will be described. FIG. 2 is an exploded view showing the inside of the motor unit 20 of the first embodiment. As shown in FIGS. 1 and 2, the fixed portion 300 includes a shaft 50, a motor stator 200, and a stator holder 250. The shaft 50 is an example of a "fixed axis".

[0020] The shaft 50 is a substantially cylindrical body. The shaft 50 is arranged around the rotation axis AX extending along the axial direction AD. In the case of an in-wheel motor, the shaft 50 constitutes the axle.

[0021] The motor stator 200 is a substantially cylindrical body. The motor stator 200 is located radially outward in the radial direction RD with respect to the shaft 50. Specifically, the motor stator 200 is arranged around a rotation axis AX extending along the axial direction AD. The motor stator 200 is fixed to the shaft 50. Also, the motor stator 200 is located radially inward in the radial direction RD of the rotor 100.

[0022] The rotor 100 is a substantially cylindrical body. The rotor 100 is located radially outward in the radial direction RD with respect to the fixed part 300. Specifically, the rotor 100 is arranged around a rotation axis AX extending along the axial direction AD. The rotor 100 surrounds the outside in the radial direction RD of the fixed part 300. The rotor 100 rotates around the rotation axis AX with respect to the fixed part 300. Such a rotor 100 is also called an outer rotor.

[0023] Specifically, the motor stator 200 includes a stator core 210, an insulator 220, a coil 230, and an insulating plate 240.

[0024] The stator core 210 is arranged around a rotation axis AX extending in the axial direction AD. As an example, the stator core 210 is substantially annular around the rotation axis AX. "Substantially annular" is, for example, "substantially circular annular". The stator core 210 is constituted by, for example, a laminated steel plate in which thin electromagnetic steel plates are laminated in the axial direction AD.

[0025] The stator core 210 has a core back and a plurality of teeth. Each of the plurality of teeth extends radially outward from the radially outer surface of the core back. The plurality of teeth are arranged at equal intervals along the circumferential direction CD.

[0026] The insulator 220 covers at least a part of the stator core 210. As an example, the insulator 220 surrounds the stator core 210 from both sides in the axial direction AD. The insulator 220 is substantially annular. "Substantially annular" is, for example, "substantially circular-ring-shaped". The insulator 220 is an electrical insulator. The insulator 220 electrically insulates the stator core 210 and the coil 230. The insulator 220 may be constituted by a single member or may be constituted by a plurality of separate members. For example, the insulator 220 is a resin molded product into which the stator core 210 is inserted. Also, the insulator 220 may have a structure that is separately attached to the stator core 210.

[0027] The coil 230 is wound around the stator core 210 via the insulator 220. The coil 230 is a coated conductor in which a metal wire is coated with a coating. The material of the metal wire is, for example, copper. However, the material of the metal wire may be aluminum instead of copper. The coating that coats the metal wire is, for example, an insulating resin.

[0028] The stator holder 250 is a disk body provided with a through hole penetrating along the axial direction AD at the center. The motor stator 200 is disposed at the radially outer end in the radial direction RD of the stator holder 250. For example, the shaft 50 is press-fitted into the through hole, and the shaft 50 and the stator holder 250 are fixed. At this time, the shaft 50 is exposed outside the stator holder 250. The shaft 50 extends from the stator holder 250 in the axial direction AD on one side (+X direction) along the rotation axis AX. Also, the shaft 50 extends from the stator holder 250 in the axial direction AD on the other side (-X direction) along the rotation axis AX.

[0029] The insulating plate 240 is formed of, for example, an insulating resin. The insulating plate 240 is disposed between the stator holder 250 and the motor stator 200. The insulating plate 240 is a substantially cylindrical body. Note that the insulating plate 240 and the insulator 220 may be integrally formed.

[0030] The rotor 100 includes a yoke 110 and a magnet 120. The magnet 120 is, for example, a permanent magnet. The magnet 120 faces the motor stator 200 on the outer side in the radial direction RD. For example, the rotor 100 may have a single substantially annular magnet 120, or may have a plurality of magnets 120 arranged in the circumferential direction CD. "Substantially annular" is, for example, "substantially circular annular". The plurality of magnets 120 are arranged such that the N poles and the S poles are alternately arranged in the circumferential direction CD. For example, the number of poles of the magnet 120 is "60". However, the number of poles of the magnet 120 is not limited to this.

[0031] The yoke 110 is a substantially cylindrical body. The yoke 110 is fixed to the outer surface of the magnet 120 in the radial direction RD. The yoke 110 is, for example, an iron member. The yoke 110 includes a first cover screw hole 111 and a second cover screw hole (not shown). Each of the first cover screw hole 111 and the second cover screw hole extends along the axial direction AD. The first cover screw hole 111 is provided on one side surface of the yoke 110 in the axial direction AD. For example, the yoke 110 includes eight first cover screw holes 111. The eight first cover screw holes 111 are arranged at equal intervals along the circumferential direction CD. The second cover screw hole is provided on the other side surface of the yoke 110 in the axial direction AD. For example, the yoke 110 includes eight second cover screw holes. The eight second cover screw holes are arranged at equal intervals along the circumferential direction CD. The first cover screw hole 111 and the second cover screw hole are alternately arranged along the circumferential direction CD.

[0032] Next, with reference to FIGS. 1 to 3, the motor 10 of the first embodiment will be described. FIG. 3 is a cross-sectional view showing the configuration of the motor 10 according to the first embodiment. As shown in FIGS. 1 to 3, the rotor 100 further includes a first cover 260, a second cover 270, a brake mechanism 280, and bearings 290 and 291.

[0033] The first cover 260 is a disk body provided with a through hole penetrating along the axial direction AD at the center. The first cover 260 is disposed on one side (+X direction) of the yoke 110 in the axial direction AD. The first cover 260 covers at least a part of the motor stator 200 and the rotor 100 from one side in the axial direction AD. The yoke 110 is fixed to the first cover 260. Specifically, the outer end portion of the first cover 260 in the radial direction RD is fixed to one side surface of the yoke 110 in the axial direction AD by a plurality of screws 261. More specifically, the screws 261 are attached to the first cover screw holes 111 from one side of the yoke 110 in the axial direction AD. For example, the number of the plurality of screws 261 is "8".

[0034] Further, the first cover 260 is rotatably disposed with respect to the shaft 50. Specifically, the first cover 260 includes a cylindrical portion 262. The cylindrical portion 262 is an example of a "bearing housing portion". The cylindrical portion 262 houses the bearing 290. The cylindrical portion 262 is located outside the bearing 290 in the radial direction RD. The cylindrical portion 262 surrounds the shaft 50 and extends along the axial direction AD. Specifically, the cylindrical portion 262 includes a cylindrical wall portion 262a.

[0035] The bearing 290 rotatably supports the first cover 260 with respect to the shaft 50. The bearing 290 is disposed between the shaft 50 and the wall portion 262a. The bearing 290 is, for example, a ball bearing or a rolling bearing.

[0036] According to the first embodiment, the first cover 260 further includes a screw seat portion 263 extending along the axial direction AD. The screw seat portion 263 is disposed inside the motor stator 200 in the radial direction RD. Note that the screw seat portion 263 may be disposed outside the motor stator 200 in the radial direction RD. That is, in the radial direction RD, the position of the screw seat portion 263 and the position of the motor stator 200 are different. Specifically, the screw seat portion 263 is provided on the wall portion 262a. Specifically, the screw seat portion 263 includes a hole extending along the axial direction AD. For example, the first cover 260 includes eight screw seat portions 263. The eight screw seat portions 263 are arranged at equal intervals along the circumferential direction CD.

[0037] The second cover 270 is a disk body provided with a through hole penetrating along the axial direction AD at the center. The second cover 270 is disposed on the other side (-X direction) of the axial direction AD of the yoke 110. The second cover 270 covers at least a part of the motor stator 200 and the rotor 100 from the other side in the axial direction AD. The yoke 110 is fixed to the second cover 270. Specifically, the outer end portion in the radial direction RD of the second cover 270 is fixed to one side surface in the axial direction AD of the yoke 110 by a plurality of screws (not shown). For example, the number of the plurality of screws is "8".

[0038] Also, the second cover 270 is rotatably disposed with respect to the shaft 50. Specifically, the second cover 270 includes a cylindrical portion 272. The cylindrical portion 272 houses the bearing 291. The cylindrical portion 272 is located outside the bearing 291 in the radial direction RD. The cylindrical portion 272 surrounds the shaft 50 and extends along the axial direction AD. Specifically, the cylindrical portion 272 includes a cylindrical wall portion 272a.

[0039] The bearing 291 rotatably supports the second cover 270 with respect to the shaft 50. The bearing 291 is disposed between the shaft 50 and the wall portion 272a. The bearing 291 is, for example, a ball bearing or a rolling bearing.

[0040] The brake mechanism 280 is a substantially cylindrical body. The brake mechanism 280 is located outside the shaft 50 in the radial direction RD. Specifically, the brake mechanism 280 is disposed around a rotation axis AX extending along the axial direction AD. The brake mechanism 280 is fixed to the second cover 270.

[0041] Note that the inner end portion in the radial direction RD of the rotor 100 directly faces the motor stator 200 without being covered by the first cover 260 and the second cover 270. The motor stator 200 is disposed between the first cover 260 and the second cover 270.

[0042] Such a motor 10 is driven by three-phase (U-phase, V-phase, and W-phase) AC power output from three output terminals of a control device. The motor 10 is driven by a control signal for the U-phase, a control signal for the V-phase, and a control signal for the W-phase. When the control signal for the U-phase, the control signal for the V-phase, and the control signal for the W-phase are input to the motor stator 200, the rotor 100 rotates along with the change in the magnetic field generated in the motor stator 200. These three-phase AC powers are connected to the motor stator 200 via a power line (not shown) from an inverter device (not shown) mounted on the electric two-wheeler 1020. The power line (not shown) is connected to the motor stator 200 through a through hole (not shown) provided in the shaft 50.

[0043] According to the first embodiment, the rim portion 400 includes a tire portion 410 and a connection portion 420. A tire is attached to the tire portion 410. The tire portion 410 is an annular member that surrounds the outer periphery of the motor portion 20.

[0044] Specifically, the tire portion 410 includes a first cylindrical portion 411, a second cylindrical portion 412, a third cylindrical portion 413, a fourth cylindrical portion 414, a fifth cylindrical portion 415, a first connection portion 431, a second connection portion 432, a third connection portion 433, and a fourth connection portion 434. The second cylindrical portion 412 is connected to one side (X direction) in the axial direction AD of the first cylindrical portion 411 via the first connection portion 431. The third cylindrical portion 413 is connected to one side (X direction) in the axial direction AD of the second cylindrical portion 412 via the second connection portion 432. The fourth cylindrical portion 414 is connected to the other side (-X direction) in the axial direction AD of the first cylindrical portion 411 via the third connection portion 433. The fifth cylindrical portion 415 is connected to the other side (-X direction) in the axial direction AD of the fourth cylindrical portion 414 via the fourth connection portion 434.

[0045] The tire part 410 becomes larger from the center in the axial direction AD of the tire part 410 toward one side in the axial direction AD, and also becomes larger from the center in the axial direction AD of the tire part 410 toward the other side in the axial direction AD. Specifically, the diameter of the second cylindrical part 412 is larger than the diameter of the first cylindrical part 411. The diameter of the third cylindrical part 413 is larger than the diameter of the second cylindrical part 412. The diameter of the fourth cylindrical part 414 is larger than the diameter of the first cylindrical part 411. The diameter of the fifth cylindrical part 415 is larger than the diameter of the fourth cylindrical part 414.

[0046] When the tire is attached to the tire part 410, the end on one side (X direction) in the axial direction AD of the tire contacts the radially outer surface of the second cylindrical part 412 and the other side in the axial direction AD of the second connecting part 432. Also, the end on the other side (-X direction) in the axial direction AD of the tire contacts the radially outer surface of the fourth cylindrical part 414 and the one side (X direction) in the axial direction AD of the fourth connecting part 434.

[0047] The connecting part 420 extends radially inward from the tire part 410. Specifically, the connecting part 420 includes a plate-like part 421 and a side surface part 422. The side surface part 422 extends in the axial direction AD from one side in the axial direction AD of the third cylindrical part 413. The plate-like part 421 is connected to one side surface in the axial direction AD of the side surface part 422.

[0048] The plate-like part 421 is a disk body provided with a through hole 424 at the center. The plate-like part 421 is arranged on one side (X direction) in the axial direction AD of the first cover 260. The end on one side in the axial direction AD of the shaft 50 is inserted into the through hole 424. Also, a plurality of through holes 425 extending in the axial direction AD are provided at the central part of the plate-like part 421. For example, the number of the plurality of through holes 425 is "8". The eight through holes 425 are arranged at equal intervals along the circumferential direction CD of the through hole 424.

[0049] According to the first embodiment, the rim portion 400 is connected to the first cover 260 by a fastening member 500. For example, the fastening member 500 is a screw. Specifically, the rim portion 400 is connected to the first cover 260 by eight screws 500. Each of the eight screws 500 is inserted into the screw seat portion 263 of the first cover 260 through the through hole 425 of the plate-like portion 421. As a result, the rim portion 400 is attached to the first cover 260. That is, the rim portion 400 is attached to the rotor 100. On the other hand, when replacing the attached rim portion 400 with a new rim portion 400, when the eight screws 500 are removed from the screw seat portion 263, the rim portion 400 is removed from the first cover 260. That is, only the rim portion 400 is removed from the motor unit 20.

[0050] As described above, according to the first embodiment, it is possible to provide a motor 10 in which the attached rim portion 400 and a new rim portion 400 can be exchanged without disassembling the motor unit 20. Further, the rim portion 400 can be easily attached and detached to and from the rotor 100 without using complicated members. Furthermore, when the motor 10 is in use, since the rim portion 400 is firmly fixed to the first cover 260 by the fastening member 500, the transmission of force from the rotor 100 to the rim portion 400 is excellent.

[0051] Also, in the radial direction RD, since the position of the screw seat portion 263 and the position of the motor stator 200 are different, even if the screw 500 is lengthened in the axial direction AD to ensure the fastening force between the motor stator 200 and the screw 500, interference between the motor stator 200 and the screw 500 can be prevented. As a result, the rim portion 400 can be firmly fixed to the first cover 260 by the fastening member 500.

[0052] And the screw seat portion 263 is provided on the wall portion 262a. As a result, when the manufacturer manufactures the motor 10, the manufacturer can easily provide the screw seat portion 263 on the first cover 260.

[0053] Furthermore, the side surface portion 422 extends from one side in the axial direction AD of the third cylindrical portion 413 toward one side in the axial direction AD. In other words, the tire portion 410 and the connection portion 420 are a single member. As a result, the number of components of the rim portion 400 can be reduced. That is, the number of components of the rim portion 400 can be made one.

[0054] For example, the rim portion 400 is formed by press working with iron or casting with aluminum.

[0055] Next, with reference to FIG. 4, an electric two-wheeler 1020 equipped with the motor 10 of the first embodiment will be described. FIG. 4 is a schematic diagram of an electric two-wheeler 1020 including the motor 10 according to the first embodiment.

[0056] As shown in FIG. 4, the motor 10 is mounted on the electric two-wheeler 1020. Examples of electric two-wheelers include electric scooters and electric motorcycles. For example, the motor 10 drives the wheels of the electric two-wheeler 1020.

[0057] The motor 10 is mounted on the electric two-wheeler 1020. In addition to the motor 10, the electric two-wheeler 1020 includes a frame 1021, a handle 1022, a front wheel 1023, a rear wheel 1024, and a saddle 1025. The rear wheel 1024 is an example of a "wheel". For example, the motor 10 is attached to the rear wheel 1024. Further, the shaft 50 of the motor 10 is attached to the frame 1021. Therefore, the rear wheel 1024 is attached to the frame 1021.

[0058] The rear wheel 1024 is rotatably supported below the rear of the frame 1021. The rear wheel 1024 rotates in contact with the ground.

[0059] In the first embodiment, the electric two-wheeler 1020 includes the motor 10, the front wheel 1023, and the rear wheel 1024 that rotates as the motor 10 rotates. Therefore, the electric two-wheeler 1020 is driven by the motor 10. Further, according to the first embodiment, the attached rim portion 400 and the new rim portion 400 can be exchanged without disassembling the motor unit 20.

[0060] (Second Embodiment) Referring to FIG. 5, the motor 2010 according to the second embodiment of the present invention will be described. FIG. 5 is a cross-sectional view showing the configuration of the motor 2010 according to the second embodiment. In the motor 10 according to the first embodiment, the tire portion 410 and the connecting portion 420 are a single member, whereas in the motor 2010 according to the second embodiment, the tire portion 2410 and the connecting portion 2420 are separate components. The connecting portion 2420 is welded to the tire portion 2410. Hereinafter, the second embodiment will be described with respect to the matters different from the first embodiment, and the description of the overlapping portions with the first embodiment will be omitted.

[0061] The rim portion 2400 according to the second embodiment includes a tire portion 2410 and a connecting portion 2420. The tire portion 2410 has a tire attached thereto. The tire portion 2410 is an annular member that surrounds the outer periphery of the motor portion 20.

[0062] The connecting portion 2420 extends radially inward in the radial direction RD from the tire portion 410. Specifically, the connecting portion 2420 includes a plate-like portion 2421 and a side surface portion 2422. The side surface portion 2422 extends in the other axial direction AD (-X direction) from the other side in the axial direction AD of the plate-like portion 2421.

[0063] The connecting portion 2420 is welded to the tire portion 2410. Note that the connecting portion 2420 may be adhered to the tire portion 2410 with an adhesive. In other words, the tire portion 2410 and the connecting portion 2420 are separate members. As a result, when the manufacturer manufactures the rim portion 400, each of the tire portion 2410 and the connecting portion 2420 can be easily produced. In particular, when a high-rigidity iron material is used for the rim portion 400, the tire portion 2410 and the connecting portion 2420 can be easily formed by punching or bending with a press. Specifically, the outer surface in the radial direction RD of the connecting portion 2420 and the inner surface in the radial direction RD of the first cylindrical portion 411 are welded.

[0064] According to the second embodiment, the rim portion 2400 is connected to the first cover 260 by the fastening member 500. For example, the fastening member 500 is a screw. Specifically, the rim portion 2400 is connected to the first cover 260 by eight screws 500. Each of the eight screws 500 is inserted into the screw seat portion 263 of the first cover 260 through the through hole 2425 of the plate-like portion 2421. As a result, the rim portion 2400 is attached to the first cover 260. That is, the rim portion 2400 is attached to the rotor 100. On the other hand, when replacing the attached rim portion 2400 with a new rim portion 2400, when the eight screws 500 are removed from the screw seat portion 263, the rim portion 2400 is removed from the first cover 260. That is, only the rim portion 2400 is removed from the motor unit 20.

[0065] As described above, according to the second embodiment, it is possible to provide the motor 2010 in which the attached rim portion 2400 and the new rim portion 2400 can be exchanged without disassembling the motor unit 20. In addition, the rim portion 2400 can be easily detached from and attached to the rotor 100 without using complicated members. Furthermore, when the motor 2010 is in use, since the rim portion 2400 is firmly fixed to the first cover 260 by the fastening member 500, the transmission of force from the rotor 100 to the rim portion 2400 is excellent.

[0066] (Third Embodiment) Referring to FIG. 6, the motor 3010 according to the third embodiment of the present invention will be described. FIG. 6 is a cross-sectional view showing the configuration of the motor 3010 according to the third embodiment. In the motor 10 according to the first embodiment, the rim portion 400 includes the tire portion 410 and the connecting portion 420, whereas in the motor 3010 according to the third embodiment, the rim portion 3400 includes a through hole 3411a. Hereinafter, the third embodiment will be described with respect to matters different from the first embodiment, and the description of the overlapping portions with the first embodiment will be omitted.

[0067] The rim portion 3400 according to the third embodiment includes a tire portion 3410. The tire portion 3410 has a tire attached thereto. The tire portion 3410 is an annular member that surrounds the outer periphery of the motor unit 20.

[0068] Specifically, the tire portion 3410 includes a first cylindrical portion 3411, a second cylindrical portion 3412, a third cylindrical portion 3413, a fourth cylindrical portion 3414, a fifth cylindrical portion 3415, a first connecting portion 3431, a second connecting portion 3432, a third connecting portion 3433, and a fourth connecting portion 3434. The second cylindrical portion 3412 is connected to one side (X direction) in the axial direction AD of the first cylindrical portion 3411 via the first connecting portion 3431. The third cylindrical portion 3413 is connected to one side (X direction) in the axial direction AD of the second cylindrical portion 3412 via the second connecting portion 3432. The fourth cylindrical portion 3414 is connected to the other side (-X direction) in the axial direction AD of the first cylindrical portion 3411 via the third connecting portion 3433. The fifth cylindrical portion 3415 is connected to the other side (-X direction) in the axial direction AD of the fourth cylindrical portion 3414 via the fourth connecting portion 3434.

[0069] The diameter of the second cylindrical portion 3412 is larger than the diameter of the first cylindrical portion 3411. The diameter of the third cylindrical portion 3413 is larger than the diameter of the second cylindrical portion 3412. The diameter of the fourth cylindrical portion 3414 is larger than the diameter of the first cylindrical portion 3411. The diameter of the fifth cylindrical portion 3415 is larger than the diameter of the fourth cylindrical portion 3414. Further, the inner surface in the radial direction RD of the first cylindrical portion 3411 is in contact with the outer surface in the radial direction RD of the yoke 3110.

[0070] When the tire is attached to the tire portion 3410, the end portion on one side (X direction) in the axial direction AD of the tire contacts the outer surface in the radial direction RD of the second cylindrical portion 3412 and the other side in the axial direction AD of the second connecting portion 3432. Also, the end portion on the other side (-X direction) in the axial direction AD of the tire contacts the outer surface in the radial direction RD of the fourth cylindrical portion 3414 and the one side in the axial direction AD of the fourth connecting portion 3434.

[0071] A plurality of through holes 3411a extending in the radial direction RD are provided in the first cylindrical portion 3411. For example, the number of the plurality of through holes 3411a is "8". The eight through holes 3411a are arranged at equal intervals along the circumferential direction CD. Thereby, it is not necessary for the rim portion 3400 to include a connecting portion, and it is possible to suppress the rim portion 3400 from having a complicated structure.

[0072] The yoke 3110 is a substantially cylindrical body. The yoke 3110 is fixed to the outer surface of the magnet 120 in the radial direction RD. The yoke 3110 is, for example, an iron member.

[0073] According to the third embodiment, the yoke 3110 includes screw holes 3110a extending along the radial direction RD. For example, the yoke 3110 includes eight screw holes 3110a. The eight screw holes 3110a are arranged at equal intervals along the circumferential direction CD.

[0074] According to the third embodiment, the rim portion 3400 is connected to the yoke 3110 by a fastening member 3500. For example, the fastening member 3500 is a screw. Specifically, when the screw 3500 is attached to the screw hole 3110a, the rim portion 3400 is connected to the yoke 3110. Specifically, the rim portion 3400 is connected to the yoke 3110 by eight screws 3500. Each of the eight screws 3500 is inserted into the screw hole 3110a of the yoke 3110 through the through hole 3411a of the first cylindrical portion 3411. As a result, the rim portion 3400 is attached to the yoke 3110. That is, the rim portion 3400 is attached to the rotor 100. On the other hand, when the operator replaces the attached rim portion 3400 with a new rim portion 3400, when the eight screws 3500 are removed from the screw holes 3110a, the rim portion 3400 is removed from the yoke 3110. That is, only the rim portion 3400 is removed from the motor unit 20.

[0075] As described above, according to the third embodiment, it is possible to provide the motor 3010 that can replace the attached rim portion 3400 with a new rim portion 3400 without disassembling the motor unit 20. Further, the rim portion 3400 can be easily attached to and detached from the rotor 100 without using complicated members. Furthermore, when the motor 3010 is in use, since the rim portion 3400 is firmly fixed to the yoke 3110 by the fastening member 3500, the transmission of force from the rotor 100 to the rim portion 3400 is excellent. Also, since the rim portion 3400 and the yoke 3110 are not fixed by welding, the rim portion 3400 and the yoke 3110 do not need to be made of the same material, and the rim portion 3400 can adopt various materials such as iron materials and aluminum.

[0076] The screw hole 3110a, the first cover screw hole 111, and the second cover screw hole are provided at different positions in the circumferential direction CD. As a result, even if the first cover screw hole 111 and the second cover screw hole are made longer to ensure the fastening force between the first cover screw hole 111 and the second cover screw hole and the screw, interference between the screw hole 3110a, the first cover screw hole 111, and the second cover screw hole can be suppressed.

[0077] Also, it is possible to additionally apply the connection structure by the fastening member 3500 of the third embodiment to the rim portions of the first embodiment and the second embodiment.

[0078] As described above, the embodiments of the present invention have been described with reference to the drawings. However, the present invention is not limited to the above-described embodiments, and can be implemented in various aspects without departing from the gist thereof. The drawings are schematically shown mainly for each component for easy understanding, and the thickness, length, number, etc. of each illustrated component are different from the actual ones for convenience of drawing creation. Also, the materials, shapes, dimensions, etc. of each component shown in the above embodiments are examples and are not particularly limited, and various changes can be made without substantially departing from the effects of the present invention.

[0079] Note that the present technology can have the following configurations.

[0080] (1) A motor unit including a fixed part and a rotating part that rotates with respect to the fixed part, a rim part that supports a tire, and wherein, the fixed part includes a fixed shaft, and a motor stator located radially outside the fixed shaft; and the rotating part includes a magnet facing radially outside the motor stator, a yoke fixed to the radially outer surface of the magnet, and a cover to which the yoke is fixed and which is rotatably arranged with respect to the fixed shaft; and the rim part is connected to at least one of the yoke and the cover by a fastening member, a motor.

[0081] (2) The cover includes a threaded seat portion extending along the axial direction, the fastening member is a screw, and the threaded seat portion is arranged radially inside or radially outside the motor stator, the motor according to (1).

[0082] (3) The rotating part further includes a bearing that rotatably supports the cover with respect to the fixed shaft, the cover further includes a bearing housing portion that houses the bearing, the bearing housing portion includes a wall portion, and the threaded seat portion is provided on the wall portion, the motor according to (2).

[0083] (4) The rim part includes a tire portion to which the tire is attached, and a connecting portion extending radially inward from the tire portion; and the tire portion and the connecting portion are a single member, the motor according to any one of (1) to (3).

[0084] (5) The rim part a tire part to which the tire is attached, a connecting part extending radially inward from the tire part, and is provided with, the connecting part is welded or adhered to the tire part, the motor according to any one of (1) to (3).

[0085] (6) The yoke is provided with a screw hole extending along the radial direction, the fastening member is a screw, by attaching the screw to the screw hole, the rim part is connected to the yoke, the motor according to any one of (1) to (3).

[0086] (7) The yoke further includes a cover screw hole extending along the axial direction, the screw hole and the cover screw hole are provided at different positions in the circumferential direction, the motor according to (6).

[0087] (8) The motor according to any one of (1) to (7), and a wheel is provided with, the motor is attached to the wheel, an electric vehicle.

Explanation of Reference Numerals

[0088] 10 Motor 50 Shaft (fixed shaft) 100 Rotor (rotating part) 110 Yoke 120 Magnet 200 Motor Stator 260 Cover 300 Motor Part (fixed part) 400 Rim Part

Claims

1. A motor unit including a fixed part and a rotating part that rotates with respect to the fixed part, and a rim part that supports a tire ; wherein the fixed part includes a fixed shaft, and a motor stator located radially outside the fixed shaft ; wherein the rotating part includes a magnet that faces the motor stator radially outside, a yoke fixed to the radially outer surface of the magnet, and a cover to which the yoke is fixed and that is rotatably arranged with respect to the fixed shaft ; wherein the rim part is connected to at least one of the yoke and the cover by a fastening member, a motor.

2. The cover includes a threaded seat portion extending along the axial direction, the fastening member is a screw, and the threaded seat portion is arranged radially inside or radially outside the motor stator, the motor according to claim 1.

3. The rotating part further includes a bearing that rotatably supports the cover with respect to the fixed shaft, the cover further includes a bearing housing portion that houses the bearing, the bearing housing portion includes a wall portion, and the threaded seat portion is provided on the wall portion, the motor according to claim 2.

4. The rim part includes a tire portion to which the tire is attached, and a connection portion extending radially inward from the tire portion ; wherein the tire portion and the connection portion are a single member, the motor according to claim 3.

5. The rim part includes a tire portion to which the tire is attached, and a connection portion extending radially inward from the tire portion ; wherein the connection portion is welded or adhered to the tire portion, the motor according to claim 3.

6. The yoke includes a threaded hole extending along the radial direction, the fastening member is a screw, and the rim part is connected to the yoke by attaching the screw to the threaded hole, the motor according to claim 1.

7. The yoke further includes a cover threaded hole extending along the axial direction, and the threaded hole and the cover threaded hole are provided at different positions in the circumferential direction, the motor according to claim 6.

8. A motor according to any one of claims 1 to 7, and a wheel ; wherein the motor is attached to the wheel, an electric vehicle.

Images