Motor and electric vehicle

Abstract

The invention provides a motor and an electric vehicle. The motor includes a fixed portion, a rotating portion, and an annular rim portion. The fixing part is fixed to a fixing shaft extending in the axial direction. The rotating part rotates relative to the fixed shaft. The rim part is fixed to the radial outer side of the rotating part. The rotating part is provided with: a first rotor housing which is positioned on one side in the axial direction and which is rotatably disposed on the fixed shaft; and a second rotor housing that is located on the other side in the axial direction and is rotatably disposed on the fixed shaft. And the first rotor shell and the second rotor shell are fixed through a fastening part. The rotating part is further provided with: a contact region that is in contact with the rim part; and an arrangement region in which the fastening member is arranged. The arrangement region is provided in a region different from the contact region in the rotating part when viewed from the radial direction.

Description

Technical Field

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

[0002] Conventionally, an in-wheel motor that is directly connected to a wheel or the like for driving has been known. (For example, refer to Patent Document 1)

[0003] In addition, a wheel including a wheel, a tire mounted on the outer periphery of the wheel, and a cover has been known. (For example, refer to Patent Document 1). A plurality of threaded holes are provided on the end surface of the outer peripheral portion of the wheel. A hole is provided on the outer peripheral portion of the cover. The cover is fixed to the wheel by aligning the threaded holes with the holes and fastening bolts to the threaded holes.

[0004] Prior Art Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2018-137864

[0006] In the wheel described in Patent Document 1, since the contact area where the tire contacts the wheel overlaps with the bolts when viewed from the radial direction of the tire, the load applied to the tire during driving sometimes is transmitted to the bolts via the wheel. As a result, fastening members such as bolts sometimes become loose. Summary of the Invention

[0007] The present invention has been made in view of the above problems, and an object thereof is to provide a motor and an electric vehicle capable of suppressing loosening of fastening members.

[0008] An exemplary motor of the present invention includes a fixed portion, a rotating portion, and an annular rim portion. The fixed portion is fixed to a fixed shaft extending in the axial direction. The rotating portion rotates relative to the fixed shaft. The rim portion is fixed to the radially outer side of the rotating portion. The rotating portion includes: a first rotor housing located on one axial side and rotatably disposed on the fixed shaft; and a second rotor housing located on the other axial side and rotatably disposed on the fixed shaft. The first rotor housing and the second rotor housing are fixed by a fastening member. The rotating portion further includes: a contact area that contacts the rim portion; and a configuration area that configures the fastening member. When viewed from the radial direction, the configuration area is located in a region of the rotating portion different from the contact area.

[0009] An exemplary electric vehicle of the present invention includes the motor described above and a wheel, and the motor is mounted on the wheel.

[0010] The effects of the present invention are as follows.

[0011] According to an exemplary aspect of the present invention, the contact area is different from the configuration area of the fastening member, so that a load applied to the fastening member can be suppressed. As a result, a motor capable of suppressing loosening of the fastening member can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 FIG. 1 is a perspective view of a motor according to a first embodiment of the present invention.

[0013] Figure 2 FIG. 2 is an exploded view of the interior of the motor according to the first embodiment.

[0014] Figure 3 FIG. 3 is a cross-sectional view showing the structure of the motor according to the first embodiment.

[0015] Figure 4 FIG. 4 is a cross-sectional view showing the structure of the motor according to the first embodiment.

[0016] Figure 5 FIG. 5 is a top view showing the structure of the yoke according to the first embodiment.

[0017] Figure 6 FIG. 6 is a schematic view of an electric two-wheeler including the motor according to the first embodiment.

[0018] Figure 7 FIG. 7 is a cross-sectional view showing the structure of the motor according to a second embodiment of the present invention.

[0019] In the figures: 10 - motor, 50 - shaft (fixed shaft), 100 - rotor (rotating part), 110 - yoke, 120 - magnet, 200 - motor stator, 260 - first rotor housing, 261 - first screw (first fastening member), 270 - second rotor housing, 300 - motor part (fixed part), 400 - rim part, S1 - first screw configuration area. DETAILED DESCRIPTION

[0020] Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. In the figures, the same or corresponding parts are denoted by the same reference numerals, and redundant description will not be repeated.

[0021] In this specification, for convenience, the rotation axis AX of the motor (see Figure 1) The direction of () is described as the horizontal direction. In the figure, 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 determined for ease of explanation and do not need to be consistent with the plumb direction. In addition, the up-down direction is defined only for ease of explanation and does not limit the orientation of the motor of the present invention during use and assembly. Moreover, the direction parallel to the rotation axis AX of the motor is only described as the "axial direction AD", and the radial direction and circumferential direction centered on the rotation axis AX of the motor are only described as the "radial direction RD" and "circumferential direction CD". In addition, in this specification, the "parallel direction" also includes a substantially parallel direction.

[0022] In addition, in this specification, the rotation axis AX of the motor sometimes coincides with the rotation axis of the rotor, but the rotation axis AX of the motor may also not coincide with the rotation axis of the rotor. In the case where the rotation axis AX of the motor does not coincide with the rotation axis of the rotor, the rotor may also rotate about a hypothetical central axis different from the rotation axis AX of the motor.

[0023] In this specification, the direction along the rotation axis AX of the motor or the direction along the rotation axis of the rotor is sometimes described as the axial direction. Therefore, in this specification, the axial direction represents the direction along the rotation axis AX that is the rotation center of the motor or the direction along the rotation axis that is the rotation center of the rotor.

[0024] (First Embodiment)

[0025] First, refer to Figure 1 to describe the motor 10 of the first embodiment of the present invention. Figure 1 is a perspective view showing the motor 10 of the first embodiment of the present invention. As Figure 1 shown, the motor 10 includes a rotor 100, a fixing portion 300, and a rim portion 400. The rotor 100 is an example of a "rotating portion".

[0026] As an example, the motor 10 is mounted on the wheel of a four-wheeled vehicle or a two-wheeled vehicle. Typically, the motor 10 is used as an in-wheel motor mounted on the axle of a four-wheeled vehicle or a two-wheeled vehicle.

[0027] The rim portion 400 supports a tire (not shown). The rim portion 400 is fixed to the outside of the rotor 100 in the radial direction RD.

[0028] Next, refer to Figure 1 and Figure 2 to describe the motor 10 of the first embodiment. Figure 2 is an exploded view showing the inside of the motor 10 of the first embodiment. As Figure 1 and Figure 2As shown, the fixing part 300 includes a shaft 50, a motor stator 200, and a stator holder 250. The shaft 50 is an example of a "fixed shaft".

[0029] The shaft 50 is a substantially cylindrical body. The shaft 50 is arranged around a rotation axis AX extending along the axial direction AD. In the case of an in-wheel motor, the shaft 50 constitutes an axle.

[0030] The motor stator 200 is a substantially cylindrical body. The motor stator 200 is located outside the shaft 50 in the radial direction RD. 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. In addition, the motor stator 200 is located radially inside the rotor 100.

[0031] The rotor 100 is a substantially cylindrical body. The rotor 100 is located outside the fixing part 300 in the radial direction RD. Specifically, the rotor 100 is arranged around a rotation axis AX extending along the axial direction AD. The rotor 100 surrounds the outside of the fixing part 300 in the radial direction RD. The rotor 100 rotates around the rotation axis AX with respect to the shaft 50. Such a rotor 100 is also called an outer rotor.

[0032] Specifically, the motor stator 200 includes a stator core 210, an insulator 220, a coil 230, and an insulating plate 240.

[0033] The stator core 210 is arranged around a rotation axis AX extending along the axial direction AD. As an example, the stator core 210 is a substantially annular shape centered on the rotation axis AX. "Substantially annular" is, for example, "substantially circular annular". The stator core 210 is composed of, for example, a laminated steel plate formed by laminating thin electromagnetic steel sheets along the axial direction AD.

[0034] The stator core 210 has a core back and a plurality of teeth. The plurality of teeth respectively extend from the outer surface of the core back in the radial direction RD to the outside in the radial direction RD. The plurality of teeth are arranged at equal intervals along the circumferential direction CD.

[0035] 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 a substantially annular shape. "Substantially annular" is, for example, "substantially circular annular". The insulator 220 is an electrical insulator. The insulator 220 electrically insulates the stator core 210 from the coil 230. The insulator 220 can be composed of a single component or multiple different components. For example, the insulator 220 is a resin molded product inserted into the stator core 210. In addition, the insulator 220 can also be a structure separately installed with respect to the stator core 210.

[0036] The coil 230 is wound around the stator core 210 with the insulator 220 interposed therebetween. The coil 230 is a covered wire in which a metal wire is coated with a film. The raw material of the metal wire is, for example, copper. However, the raw material of the metal wire can also be replaced with aluminum instead of copper. The film covering the covered wire is, for example, an insulating resin.

[0037] The stator holder 250 is a disk-shaped body having a through hole penetrating along the axial direction AD at the center. The motor stator 200 is disposed at the outer end portion in the radial direction RD of the stator holder 250. For example, the shaft 50 is press-fitted into the through hole to fix the shaft 50 and the stator holder 250. At this time, the shaft 50 protrudes outside the stator holder 250. The shaft 50 extends from the stator holder 250 along the rotation axis AX to one side (+X direction) in the axial direction AD. In addition, the shaft 50 extends from the stator holder 250 along the rotation axis AX to the other side (-X direction) in the axial direction AD.

[0038] 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. In addition, the insulating plate 240 and the insulator 220 may be integrally formed.

[0039] 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 alternately arranged with N poles and S poles side by side 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.

[0040] The yoke 110 is a substantially cylindrical body. In the axial direction AD, the length of the yoke 110 is a first distance L1 (refer to Figure 5 ). The yoke 110 is, for example, an iron-made member. The yoke 110 is fixed to the outer side surface in the radial direction RD of the magnet 120. The yoke 110 has a first cover threaded hole 111 and a second cover threaded hole (not shown). The first cover threaded hole 111 and the second cover threaded hole extend along the axial direction AD, respectively.

[0041] The first cover threaded hole 111 is provided on one side surface of the yoke 110 in the axial direction AD. The first cover threaded hole 111 is formed from one side surface of the yoke 110 in the axial direction AD to a second distance L2 (refer to Figure 5 ). The second distance L2 is shorter than half of the first distance L1, and is preferably 1 / 3 or less of the first distance L1. For example, eight first cover threaded holes 111 are formed in the yoke 110. The eight first cover threaded holes 111 are arranged at equal intervals along the circumferential direction CD.

[0042] The second cover threaded holes are provided on the other side surface of the yoke 110 in the axial direction AD. The second cover threaded holes are formed from the other side surface of the yoke 110 in the axial direction AD to a second distance L2 (refer to Figure 5 ). For example, eight second cover threaded holes are formed in the yoke 110. The eight second cover threaded holes are arranged at equal intervals along the circumferential direction CD. In addition, the first cover threaded holes 111 and the second cover threaded holes are arranged alternately along the circumferential direction CD.

[0043] Next, referring to Figures 1 to 4 , the motor 10 of the first embodiment will be described. Figure 3 FIG. is a cross-sectional view showing the structure of the motor 10 of the first embodiment. Figure 4 FIG. is a cross-sectional view showing the structure of the motor 10 of the first embodiment. Figure 5 FIG. is a plan view showing the structure of the yoke 110 of the first embodiment. In addition, Figure 3 FIG. is a cross-sectional view taken along a line connecting the first cover threaded holes 111 and the first cover threaded holes 111. In addition, Figure 4 FIG. is a cross-sectional view taken along a line connecting the second cover threaded holes. As Figures 1 to 4 shown, the rotor 100 further includes a first rotor housing 260, a second rotor housing 270, a braking mechanism 280, and bearings 290, 291.

[0044] The first rotor housing 260 is a disk-shaped body having a through hole penetrating therethrough along the axial direction AD at the center. The first rotor housing 260 is located on one side (+X direction) of the yoke 110 in the axial direction AD. The first rotor housing 260 covers at least a part of the motor stator 200 and the rotor 100 from one side in the axial direction AD. The first rotor housing 260 is fixed to the yoke 110.

[0045] Specifically, the radially outer end of the first rotor housing 260 is fixed to the one side surface of the yoke 110 in the axial direction AD by a plurality of first screws 261. The first screw 261 is an example of the "first fastening member". Specifically, the first screw 261 is mounted on the first cover threaded hole 111 from one side in the axial direction AD of the yoke 110. The length of the first screw 261 in the axial direction AD is a third distance L3. In addition, the length of the first screw 261 in the axial direction AD refers to the length of the shaft portion of the screw except for the head. The third distance L3 is equal to or less than the second distance L2, and preferably is the second distance L2. For example, the number of the plurality of first screws 261 is "8", but is not limited thereto.

[0046] In addition, the first rotor housing 260 is configured to be rotatable relative to the shaft 50. Specifically, the first rotor housing 260 includes a cylindrical portion 262. The cylindrical portion 262 houses a bearing 290. The cylindrical portion 262 is located radially 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.

[0047] The bearing 290 supports the first rotor housing 260 so as to be rotatable relative 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.

[0048] The second rotor housing 270 is a disk-shaped body having a through hole penetrating therethrough along the axial direction AD at the center. The second rotor housing 270 is located on the other side (-X direction) of the magnetic yoke 110 in the axial direction AD. The second rotor housing 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 second rotor housing 270 is fixed to the magnetic yoke 110.

[0049] Specifically, the radially outer end portion of the second rotor housing 270 is fixed to the one axial surface of the magnetic yoke 110 by a plurality of second screws 271. The second screw 271 is an example of the "second fastening member". Specifically, the second screw 271 is installed in the second cover threaded hole 112 from the other side in the axial direction AD of the magnetic yoke 110. The axial length of the second screw 271 in the axial direction AD is a third distance L3. In addition, the axial length of the second screw 271 in the axial direction AD refers to the length of the shaft portion of the screw excluding the head. The third distance L3 is equal to or less than the second distance L2, and preferably equal to the second distance L2. The axial lengths of the first screw 261 and the second screw 271 in the axial direction AD are preferably the same. For example, the number of the plurality of second screws 271 is "8".

[0050] The first rotor housing 260 and the magnetic yoke 110 are fixed by the first screw 261, and the second rotor housing 270 and the magnetic yoke 110 are fixed by the second screw 271. In other words, the first rotor housing 260 and the second rotor housing 270 are fixed via the magnetic yoke 110 by the first screw 261 and the second screw 271. In addition, a first screw arrangement region S1 in which the first screw 261 is arranged is included in a first region SA from the one side in the axial direction AD of the magnetic yoke 110 to the third distance L3, a second screw arrangement region S2 in which the second screw 271 is arranged is included in a second region SB from the other side in the axial direction AD of the magnetic yoke 110 to the third distance L3, and a central region SS is formed between the first region SA and the second region SB.

[0051] In addition, the second rotor housing 270 is configured to be rotatable relative to the shaft 50. Specifically, the second rotor housing 270 includes a cylindrical portion 272. The cylindrical portion 272 houses a bearing 291. The cylindrical portion 272 is located radially outward of 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.

[0052] The bearing 291 supports the second rotor housing 270 so as to be rotatable relative 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.

[0053] The brake mechanism 280 is a substantially cylindrical body. The brake mechanism 280 is located radially outward of 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 rotor housing 270.

[0054] In addition, the inner end portion of the rotor 100 in the radial direction RD is not covered by the first rotor housing 260 and the second rotor housing 270 and directly faces the motor stator 200. The motor stator 200 is disposed between the first rotor housing 260 and the second rotor housing 270.

[0055] Such a motor 10 is driven by three-phase (U-phase, V-phase, and W-phase) alternating current power output from three output terminals of the control device. The motor 10 is driven by a control signal of the U-phase, a control signal of the V-phase, and a control signal of the W-phase. When the control signal of the U-phase, the control signal of the V-phase, and the control signal of the W-phase are input to the motor stator 200, the rotor 100 rotates as the magnetic field generated in the motor stator 200 changes. This three-phase alternating current power is connected from an inverter device (not shown) mounted on the electric two-wheeler 1020 to the motor stator 200 via a power line (not shown). The power line (not shown) is connected to the motor stator 200 through a through hole (not shown) provided in the shaft 50.

[0056] A tire is mounted on the rim portion 400. The rim portion 400 is fixed to the outside of the rotor 100 in the radial direction RD. The rim portion 400 is an annular member that surrounds the outer periphery of the rotor 100. For example, the material of the rim portion 400 is iron or aluminum, and preferably the same material as that of the yoke 110.

[0057] Specifically, the rim portion 400 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 connecting portion 431, a second connecting portion 432, a third connecting portion 433, and a fourth connecting 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 connecting 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 connecting 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 connecting 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 connecting portion 434.

[0058] The rim portion 400 expands from the center in the axial direction AD of the rim portion 400 toward one side in the axial direction AD, and expands from the center in the axial direction AD of the rim portion 400 toward the other side in the axial direction AD. The diameter of the second cylindrical portion 412 is larger than the diameter of the first cylindrical portion 411. The diameter of the third cylindrical portion 413 is larger than the diameter of the second cylindrical portion 412. The diameter of the fourth cylindrical portion 414 is larger than the diameter of the first cylindrical portion 411. The diameter of the fifth cylindrical portion 415 is larger than the diameter of the fourth cylindrical portion 414.

[0059] In addition, the outer surface of the yoke 110 in the radial direction RD contacts the inner surface of the first cylindrical portion 411 in the radial direction RD. Specifically, a contact area that contacts the rim portion 400 and a non-contact area that does not contact the rim portion 400 are formed on the outer surface of the yoke 110 in the radial direction RD. In other words, the rotor 100 further includes a contact area, a first screw arrangement area S1, and a second screw arrangement area S2. The contact area is located in the central area SS. That is, when viewed from the radial direction RD, the first screw arrangement area S1 and the second screw arrangement area S2 are provided in areas of the rotor 100 that are different from the contact area. In addition, "when viewed from the radial direction RD, the first screw arrangement area S1 and the second screw arrangement area S2 are provided in areas of the rotor 100 that are different from the contact area" means that when viewed from the radial direction RD, the contact area does not overlap with the first screw arrangement area S1 and the second screw arrangement area S2.

[0060] Alternatively, the entire inner surface of the first cylindrical portion 411 in the radial direction RD may be in contact with the outer surface of the yoke 110 in the radial direction RD, or a part of the inner surface of the first cylindrical portion 411 in the radial direction RD may be in contact with the outer surface of the yoke 110 in the radial direction RD. For example, the central portion of the first cylindrical portion 411 in the axial direction AD may protrude outward in the radial direction RD, and both end portions of the first cylindrical portion 411 in the axial direction AD may be in contact with the outer surface of the yoke 110 in the radial direction RD. In this case, the contact area may be an area including both end portions of the first cylindrical portion 411 in the axial direction AD and the central portion of the first cylindrical portion 411 in the axial direction AD.

[0061] Specifically, when viewed from the radial direction RD, the contact area is disposed between the front end portions of the first screw 261 and the second screw 271. Additionally, preferably, when viewed from the radial direction RD, the contact area is disposed between the front end portions of the first cover threaded hole 111 and the second cover threaded hole 112. Moreover, the inner surface of the first cylindrical portion 411 in the radial direction RD and the outer surface of the yoke 110 in the radial direction RD are welded.

[0062] When the tire is mounted on the rim portion 400, the end portion on one side (X direction) in the axial direction AD of the tire is in contact with the outer surface of the second cylindrical portion 412 in the radial direction RD and the other side in the axial direction AD of the second connecting portion 432. Additionally, the end portion on the other side (-X direction) in the axial direction AD of the tire is in contact with the outer surface of the fourth cylindrical portion 414 in the radial direction RD and the one side (X direction) in the axial direction AD of the fourth connecting portion 434.

[0063] As described above, according to the first embodiment, when viewed from the radial direction RD, the first screw arrangement region S1 and the second screw arrangement region S2 are provided in regions of the rotor 100 that are different from the contact area. As a result, when driving, the load from the tire is applied to the contact area. On the other hand, the load from the tire is not applied to the first screw arrangement region S1 and the second screw arrangement region S2. Therefore, it is possible to suppress the load from the tire from being applied to the first screw 261 and the second screw 271. As a result, a motor 10 that can suppress loosening of the first screw 261 and the second screw 271 can be provided.

[0064] In addition, since the contact area represents the area where the outer surface of the yoke 110 is in contact with the rim portion 400, it is possible to suppress the first screw 261 and the second screw 271 from coming out of the yoke 110.

[0065] In addition, when viewed from the radial direction RD, the contact area is disposed between the front end portions of the first screw 261 and the second screw 271. That is, the contact area is disposed at the central portion of the yoke 110, so that the yoke 110 and the rim portion 400 can be firmly fixed.

[0066] In addition, when viewed from the radial direction RD, the contact area is disposed between the front end portions of the first cover threaded hole 111 and the second cover threaded hole 112, so that overlap between the contact area and the first screw 261 and the second screw 271 can be reliably suppressed.

[0067] In addition, the length of the axial direction AD of the first screw 261 is the same as the length of the axial direction AD of the second screw 271, so that the type of the first screw 261 can be the same as the type of the second screw 271. As a result, an increase in the types of parts can be suppressed.

[0068] In addition, the length of the axial direction AD of the first screw 261 and the length of the axial direction AD of the second screw 271 are each shorter than half of the length of the axial direction AD of the yoke 110, so that a decrease in the area of the contact area can be suppressed.

[0069] Moreover, the rim portion 400 increases from the center in the axial direction AD of the rim portion 400 toward one side in the axial direction AD and increases from the center in the axial direction AD of the rim portion 400 toward the other side in the axial direction AD. That is, since the rim portion 400 is disposed at the center portion of the yoke 110, the yoke 110 and the rim portion 400 can be firmly fixed.

[0070] Furthermore, since the yoke 110 and the rim portion 400 are welded in the contact area, the yoke 110 and the rim portion 400 can be fixed more firmly.

[0071] Next, with reference to Figure 6 An electric two-wheeler 1020 equipped with the motor 10 of the first embodiment will be described. Figure 6 It is a schematic view of the electric two-wheeler 1020 equipped with the motor 10 of the first embodiment.

[0072] As Figure 6 shown, the motor 10 is mounted on the electric two-wheeler 1020. Examples of the electric two-wheeler include an electric scooter and an electric motorcycle. For example, the motor 10 drives the wheels of the electric two-wheeler 1020.

[0073] The motor 10 is mounted on the electric two-wheeler 1020. The electric two-wheeler 1020 includes, in addition to the motor 10, a vehicle 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 the "wheel". For example, the motor 10 is mounted on the rear wheel 1024. Moreover, the shaft 50 of the motor 10 is mounted on the vehicle frame 1021. Therefore, the rear wheel 1024 is mounted on the vehicle frame 1021.

[0074] The rear wheel 1024 is rotatably supported below the rear of the vehicle frame 1021. The rear wheel 1024 contacts the ground and rotates.

[0075] In the first embodiment, the electric two-wheeler 1020 includes a motor 10, a front wheel 1023, and a rear wheel 1024 that rotates as the motor 10 rotates. Therefore, the driving of the electric two-wheeler 1020 can be supported by the motor 10. Further, according to the first embodiment, when traveling, a load from the tire is applied to the contact area. On the other hand, a load from the tire is not applied to the first screw arrangement area S1 and the second screw arrangement area S2. Therefore, it is possible to suppress the load from the tire from being applied to the first screw 261 and the second screw 271. As a result, loosening of the first screw 261 and the second screw 271 can be suppressed.

[0076] (Second Embodiment)

[0077] Refer to Figure 7 to describe the motor 2010 of the second embodiment of the present invention. Figure 7 is a cross-sectional view showing the structure of the motor 2010 of the second embodiment. The motor 10 of the first embodiment is an outer rotor, whereas the motor 2010 of the second embodiment is an inner rotor. Hereinafter, regarding the second embodiment, matters different from the first embodiment will be described, and the description of parts overlapping with the first embodiment will be omitted.

[0078] The motor stator 200 is a substantially cylindrical body. The motor stator 200 is located on the outer side in the radial direction RD with respect to the shaft 50. Specifically, the motor stator 200 is arranged centered on the rotation axis AX extending along the axial direction AD. The motor stator 200 is fixed to the shaft 50.

[0079] The rotor 100 includes a yoke 1110, a magnet 1120, a first rotor housing 1260, a second rotor housing 1270, a braking mechanism 280, and bearings 1290 and 1291.

[0080] The magnet 1120 is, for example, a permanent magnet. The magnet 1120 faces the motor stator 200 on the inner side in the radial direction RD.

[0081] The yoke 1110 is a substantially cylindrical body. The yoke 1110 is, for example, an iron component. The yoke 1110 is fixed to the inner surface of the magnet 1120 in the radial direction RD.

[0082] The first rotor housing 1260 is a disk-shaped body having a through hole penetrating along the axial direction AD at the center. The first rotor housing 1260 is located on one side (+X direction) of the yoke 1110 in the axial direction AD. The first rotor housing 1260 is fixed to the yoke 1110.

[0083] In addition, the first rotor housing 1260 is configured to be rotatable relative to the shaft 50. Specifically, the first rotor housing 1260 includes a cylindrical portion 1262. The cylindrical portion 1262 houses a bearing 1290. The cylindrical portion 1262 is located radially outside the bearing 1290 in the radial direction RD. The cylindrical portion 1262 surrounds the shaft 50 and extends along the axial direction AD. Specifically, the cylindrical portion 1262 includes a cylindrical wall portion 1262a.

[0084] The bearing 1290 supports the first rotor housing 1260 so as to be rotatable relative to the shaft 50. The bearing 1290 is disposed between the shaft 50 and the wall portion 1262a. The bearing 1290 is, for example, a ball bearing or a rolling bearing.

[0085] The second rotor housing 1270 includes a disk body having a through hole penetrating therethrough along the axial direction AD at the center and a side surface portion 1271. The second rotor housing 1270 is located on the other side (-X direction) of the yoke 1110 in the axial direction AD.

[0086] The side surface portion 1271 extends from the outer end portion of the disk body toward one side in the axial direction AD. Specifically, the side surface portion 1271 is a substantially cylindrical body. The side surface portion 1271 is located radially outside the motor stator 200 in the radial direction RD.

[0087] The side surface portion 1271 has a threaded hole 1111. The threaded hole 1111 extends along the axial direction AD. The threaded hole 1111 is provided on one side surface of the side surface portion 1271 in the axial direction AD. For example, eight threaded holes 1111 are formed in the side surface portion 1271. The eight threaded holes 1111 are arranged at equal intervals along the circumferential direction CD.

[0088] In addition, the second rotor housing 1270 is configured to be rotatable relative to the shaft 50. Specifically, the second rotor housing 1270 includes a cylindrical portion 1272. The cylindrical portion 1272 houses a bearing 1291. The cylindrical portion 1272 is located radially outside the bearing 1291 in the radial direction RD. The cylindrical portion 1272 surrounds the shaft 50 and extends along the axial direction AD. Specifically, the cylindrical portion 1272 includes a cylindrical wall portion 1272a.

[0089] The bearing 1291 supports the second rotor housing 1270 so as to be rotatable relative to the shaft 50. The bearing 1291 is disposed between the shaft 50 and the wall portion 1272a. The bearing 1291 is, for example, a ball bearing or a rolling bearing.

[0090] Specifically, the radially outer end portion of the first rotor housing 1260 is fixed to one side surface of the side surface portion 1271 of the second rotor housing 1270 in the axial direction AD by a plurality of screws 1261. The screws 1261 are an example of "fastening members". That is, in a region from one side in the axial direction AD of the side surface portion 1271 to a predetermined distance, there is a screw arrangement region S3 in which the screws 1261 are arranged.

[0091] In addition, the radially outer side of the side surface portion 1271 of the second rotor housing 1270 contacts the radially inner side of the first cylindrical portion 411. Specifically, a contact area that contacts the rim portion 400 and a non-contact area that does not contact the rim portion 400 are formed in the side surface portion 1271 of the second rotor housing 270. The screw arrangement area S3 is located in the non-contact area. That is, when viewed from the radial direction RD, a region different from the contact area in the second rotor housing 270 has the screw arrangement area S3. Further, the radially inner side of the first cylindrical portion 411 and the radially outer side of the side surface portion 1271 of the second rotor housing 270 are welded together.

[0092] As described above, according to the second embodiment, when viewed from the radial direction RD, a region different from the contact area in the second rotor housing 270 has the screw arrangement area S3. As a result, when the vehicle is running, the load from the tire is applied to the contact area. On the other hand, the load from the tire is not applied to the screw arrangement area S3. Therefore, it is possible to suppress the load from the tire being applied to the screw 1261. As a result, it is possible to provide the motor 2010 in which loosening of the screw 1261 can be suppressed.

[0093] As described above, 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 ways without departing from the gist thereof. For ease of understanding, the drawings schematically show each structural element. The thickness, length, number, etc. of each structural element shown in the drawings are different from the actual ones for the convenience of drawing production. In addition, the materials, shapes, dimensions, etc. of each structural element shown in the above-described embodiments are examples and are not particularly limited, and various changes can be made without substantially departing from the effects of the present invention.

[0094] In addition, the present technology can adopt the following structure.

[0095] (1) A motor, comprising:

[0096] A fixing portion fixed to a fixing shaft extending in the axial direction;

[0097] A rotating portion that rotates relative to the fixing shaft; and

[0098] A ring-shaped rim portion fixed to the radially outer side of the rotating portion,

[0099] The rotating portion includes:

[0100] A first rotor housing located on one axial side and rotatably arranged on the fixing shaft; and

[0101] A second rotor housing, which is located on the other axial side and is rotatably disposed on the fixed shaft,

[0102] The first rotor housing and the second rotor housing are fixed by fastening members.

[0103] The rotating portion further includes:

[0104] A contact area that contacts the rim portion; and

[0105] A configuration area that configures the fastening members.

[0106] When viewed from the radial direction, the configuration area is provided in a region of the rotating portion different from the contact area.

[0107] (2) The motor according to (1),

[0108] The fastening members include a first fastening member and a second fastening member.

[0109] The rotating portion further includes a yoke located radially outside the fixed portion.

[0110] The first rotor housing is fixed to the yoke by the first fastening member.

[0111] The second rotor housing is fixed to the yoke by the second fastening member.

[0112] The contact area indicates the area where the rim portion contacts the yoke.

[0113] (3) The motor according to (1),

[0114] The first fastening member is installed from one axial side of the yoke.

[0115] The second fastening member is installed from the other axial side of the yoke.

[0116] When viewed from the radial direction, the contact area is disposed between the front end portions of the first fastening member and the second fastening member.

[0117] (4) The motor according to (2) or (3),

[0118] The yoke includes:

[0119] A first threaded hole for installing the first fastening member; and

[0120] A second threaded hole for installing the second fastening member.

[0121] When viewed from the radial direction, the contact area is disposed between the front end portions of the first threaded hole and the second threaded hole.

[0122] (5) The motor according to any one of (2) to (4),

[0123] The axial length of the first fastening member is the same as the axial length of the second fastening member.

[0124] The contact area is located at the axial center of the yoke.

[0125] (6) The motor according to any one of (2) to (5),

[0126] The axial length of the first fastening member and the axial length of the second fastening member are each shorter than half of the axial length of the yoke.

[0127] (7) The motor according to any one of (2) to (6),

[0128] The rim portion becomes larger from the axial center of the rim portion toward one side in the axial direction and becomes larger from the axial center of the rim portion toward the other side in the axial direction.

[0129] (8) The motor according to any one of (2) to (7),

[0130] In the contact area, the yoke and the rim portion are welded.

[0131] (9) An electric vehicle, comprising:

[0132] (1) to (8) The motor according to any one of the above; and a wheel,

[0133] The motor is mounted on the wheel.

Claims

1. A motor, characterized in that: have: A fixing portion fixed to a fixing shaft extending in the axial direction; a rotating portion that rotates relative to the fixed shaft; and an annular rim portion fixed to the radially outer side of the rotating portion, The rotating part comprises: a first rotor housing located on one side of the axial direction and rotatably disposed on the fixed shaft; and a second rotor housing located on the other side of the axial direction and rotatably arranged on the fixed shaft; The first rotor housing and the second rotor housing are fixed by a fastening member, The rotating part further comprises: a contact area that contacts the rim portion; and a configuration area, which configures the fastening component, When viewed in the radial direction, the rotation portion has the arrangement region in a region different from the contact region.

2. The motor according to claim 1, characterized in that The fastening member includes a first fastening member and a second fastening member. The rotating part further includes a yoke located radially outside the fixed part. The first rotor housing is fixed to the yoke by the first fastening member, The second rotor housing is fixed to the yoke by the second fastening member, The contact region refers to a region where the rim portion contacts the yoke.

3. The motor according to claim 2, characterized in that The first fastening member is mounted from one axial side of the yoke. The second fastening member is mounted from the other axial side of the yoke. The contact region is arranged between a front end portion of the first fastening member and a front end portion of the second fastening member when viewed in the radial direction.

4. The motor according to claim 3, characterized in that The yoke comprises: a first threaded hole for mounting the first fastening member; and a second threaded hole, which mounts the second fastening member, When viewed in the radial direction, the contact region is arranged between the front end portion of the first threaded hole and the front end portion of the second threaded hole.

5. The motor according to claim 2, characterized in that The axial length of the first fastening member is the same as the axial length of the second fastening member. The contact region is located at the center of the yoke in the axial direction.

6. The motor according to claim 2, characterized in that The axial length of the first fastening member and the axial length of the second fastening member are each shorter than half the axial length of the yoke.

7. The motor according to claim 2, characterized in that The rim portion increases in size from the axial center of the rim portion toward one side in the axial direction, and increases in size from the axial center of the rim portion toward the other side in the axial direction.

8. The motor according to claim 2, characterized in that The yoke and the rim portion are welded in the contact region.

9. An electric vehicle, characterized in that: have: The motor according to any one of claims 1 to 8; and wheel, The motor is mounted on the wheel.

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