Motor and electric vehicle

Abstract

To provide a motor capable of suppressing loosening of a fastening member, and an electric vehicle.SOLUTION: A motor 10 comprises a stationary part 50, a rotary part and an annular rim part 400. The stationary part is fixed to a fixture shaft extending in an axial direction. The rotary part is rotated with respect to the fixture shaft. The rim part is fixed radially outside of the rotary part. The rotary part includes: a first rotor housing 260 which is positioned at one side in the axial direction and disposed rotatably on the fixture shaft; and a second rotor housing 270 which is positioned at the other side in the axial direction and disposed rotatably on the fixture shaft. The first rotor housing and the second rotor housing are fixed by a fastening member. The rotary part further includes a contact region in contact with the rim part and an arrangement region in which the fastening member is arranged. In a view in the axial direction, there is the arrangement region in a region, that is different from the contact region, in the rotary part.SELECTED DRAWING: Figure 3

Description

Technical Field

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

Background Art

[0002] Conventionally, in-wheel motors that are directly connected to wheels and driven are known. (For example, see Patent Document 1).

[0003] Also, a wheel including a wheel, a tire mounted on the outer periphery of the wheel, and a cover is known (for example, see Patent Document 1). A plurality of screw holes are provided in the end face of the outer peripheral portion of the wheel. A hole is provided in the outer peripheral portion of the cover. By aligning the screw hole and the hole and fastening a bolt to the screw hole, the cover is fixed to the wheel.

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 viewed from the radial direction of the tire, the contact region where the tire and the wheel contact overlaps with the bolt, so that the load applied to the tire during traveling may be transmitted to the bolt via the wheel. As a result, fastening members such as bolts may become loose.

[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 suppressing loosening of a fastening member.

Means for Solving the Problems

[0007] An exemplary motor according to the present disclosure includes a fixed part, a rotating part, and an annular rim part. The fixed part is fixed to a fixed shaft extending along the axial direction. The rotating part rotates with respect to the fixed shaft. The rim part is fixed to the outside in the radial direction of the rotating part. The rotating part includes a first rotor housing located on one side in the axial direction and rotatably arranged on the fixed shaft, and a second rotor housing located on the other side in 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 includes a contact area in contact with the rim part and an arrangement area where the fastening member is arranged. The arrangement area is in a region different from the contact area in the rotating part when viewed from the radial direction.

[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.

Advantages of the Invention

[0009] According to the exemplary present disclosure, since the contact area is different from the arrangement area of the fastening member, it is possible to suppress the application of a load to the fastening member. As a result, it is possible to provide a motor that can suppress the loosening of the fastening member.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

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, there may be cases where the direction of the rotation axis AX (see FIG. 1) of the motor is 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 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. For this reason, in this specification, the axial direction indicates the direction along the rotation axis AX that is the rotation center of the motor or the rotation axis that is the rotation center of the rotor.

[0015] (First Embodiment) First, referring 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 rotor 100, a fixed portion 300, and a rim portion 400. The rotor 100 is an example of a "rotating portion".

[0016] The motor 10 is, as an example, attached to the wheels of a four-wheeled vehicle or a two-wheeled vehicle. 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 rim portion 400 supports a tire (not shown). The rim portion 400 is fixed to the outside in the radial direction RD of the rotor 100.

[0018] Next, referring to FIGS. 1 and 2, the motor 10 of the first embodiment will be described. FIG. 2 is an exploded view showing the inside of the motor 10 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 shaft".

[0019] 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 the axle.

[0020] The motor stator 200 is a substantially cylindrical body. The motor stator 200 is located outside 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 inside in the radial direction of the rotor 100.

[0021] 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 shaft 50. Such a rotor 100 is also called an outer rotor.

[0022] Specifically, the motor stator 200 includes a stator core 210, an insulator 220, a coil 230, and an insulating plate 240.

[0023] 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 composed of, for example, a laminated steel plate in which thin electromagnetic steel plates are laminated in the axial direction AD.

[0024] 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.

[0025] 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 annular". 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 composed of a single member or 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.

[0026] 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.

[0027] The stator holder 250 is a disc-shaped body provided with a through-hole penetrating along the axial direction AD at its center. The motor stator 200 is disposed at the 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 one axial direction AD side (+X direction) along the rotation axis AX. Also, the shaft 50 extends from the stator holder 250 in the other axial direction AD side (-X direction) along the rotation axis AX.

[0028] 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.

[0029] 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 outside 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 ring-shaped". The plurality of magnets 120 are arranged such that the N poles and the S poles alternate 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.

[0030] The yoke 110 is a substantially cylindrical body. In the axial direction AD, the length of the yoke 110 is the first distance L1 (see FIG. 5). The yoke 110 is, for example, an iron member. The yoke 110 is fixed to the radially outer surface of the magnet 120 in the radial direction RD. 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.

[0031] The first cover screw hole 111 is provided on one side surface of the yoke 110 in the axial direction AD. The first cover screw hole 111 is formed from one side surface of the yoke 110 in the axial direction AD to the second distance L2 (see FIG. 5). The second distance L2 is preferably shorter than half of the first distance L1 and not more than 1 / 3 of the first distance L1. For example, eight first cover screw holes 111 are formed in the yoke 110. The eight first cover screw holes 111 are arranged at equal intervals along the circumferential direction CD.

[0032] The second cover screw hole is provided on the other side surface of the yoke 110 in the axial direction AD. The second cover screw hole is formed from the other side surface of the yoke 110 in the axial direction AD to the second distance L2 (see FIG. 5). For example, eight second cover screw holes are formed in the yoke 110. The eight second cover screw holes are arranged at equal intervals along the circumferential direction CD. Note that the first cover screw hole 111 and the second cover screw hole are alternately arranged along the circumferential direction CD.

[0033] Next, referring to FIGS. 1 to 4, 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. FIG. 4 is a cross-sectional view showing the configuration of the motor 10 according to the first embodiment. FIG. 5 is a plan view showing the configuration of the yoke 110 according to the first embodiment. Note that FIG. 3 is a cross-sectional view cut along a line connecting the first cover screw holes 111. Also, FIG. 4 is a cross-sectional view cut along a line connecting the second cover screw holes. As shown in FIGS. 1 to 4, the rotor 100 further includes a first rotor housing 260, a second rotor housing 270, a brake mechanism 280, and bearings 290 and 291.

[0034] The first rotor housing 260 is a disk body provided with a through hole penetrating along the axial direction AD at its 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.

[0035] Specifically, the outer end portion of the first rotor housing 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 first screws 261. The first screw 261 is an example of a "first fastening member". Specifically, the first screw 261 is attached to the first cover screw hole 111 from one side of the yoke 110 in the axial direction AD. The length of the first screw 261 in the axial direction AD is the third distance L3. Note that the length of the first screw 261 in the axial direction AD refers to the length of the shaft portion excluding the head of the screw. The third distance L3 is less than or equal to the second distance L2, and preferably equal to the second distance L2. For example, the number of the plurality of first screws 261 is "8", but it is not limited thereto.

[0036] Also, the first rotor housing 260 is rotatably arranged with respect 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 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.

[0037] The bearing 290 rotatably supports the first rotor housing 260 with respect to the shaft 50. The bearing 290 is arranged between the shaft 50 and the wall portion 262a. The bearing 290 is, for example, a ball bearing or a rolling bearing.

[0038] The second rotor housing 270 is a disc body provided with a through hole penetrating along the axial direction AD at its center. The second rotor housing 270 is located on the other side (-X direction) of the 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 yoke 110.

[0039] Specifically, the outer end portion of the second rotor housing 270 in the radial direction R is fixed to one side surface of the yoke 110 in the axial direction AD by a plurality of second screws 271. The second screw 271 is an example of a "second fastening member". Specifically, the second screw 271 is attached to the second cover screw hole 112 from the other side in the axial direction AD of the yoke 110. The length of the second screw 271 in the axial direction AD is the third distance L3. Note that the length of the second screw 271 in the axial direction AD refers to the length of the shaft portion excluding the head of the screw. The third distance L3 is less than or equal to the second distance L2, and preferably equal to the second distance L2. The length of the first screw 261 in the axial direction AD and the length of 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".

[0040] The first rotor housing 260 and the yoke 110 are fixed by the first screw 261, and the second rotor housing 270 and the 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 by the first screw 261 and the second screw 271 via the yoke 110. Also, a first screw arrangement region S1 in which the first screw 261 is arranged is included in a first region SA from one side in the axial direction AD of the yoke 110 to the third distance L3, and 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 yoke 110 to the third distance L3, and a central region SS is formed between the first region SA and the second region SB.

[0041] Further, the second rotor housing 270 is rotatably disposed with respect 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 262 is located radially outward of the bearing 290 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.

[0042] The bearing 291 rotatably supports the second rotor housing 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.

[0043] 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.

[0044] Note that the inner end portion of the rotor 100 in the radial direction RD faces the motor stator 200 directly without being covered by the first rotor housing 260 and the second rotor housing 270. The motor stator 200 is disposed between the first rotor housing 260 and the second rotor housing 270.

[0045] 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 U-phase control signal, a V-phase control signal, and a W-phase control signal. When the U-phase control signal, the V-phase control signal, and the W-phase control signal 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.

[0046] The tire is attached to the rim portion 400. The rim portion 400 is fixed to the outside in the radial direction RD of the rotor 100. The rim portion 400 is an annular member surrounding the outer circumference of the rotor 100. For example, the material of the rim portion 400 is preferably a ferrous material or aluminum, and the same material as that of the yoke 110.

[0047] 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 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.

[0048] The rim portion 400 becomes larger from the center in the axial direction AD of the rim portion 400 toward one side in the axial direction AD, and also becomes larger 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.

[0049] Further, the radially outer surface of the yoke 110 in the radial direction RD contacts the radially inner surface of the first cylindrical portion 411. Specifically, a contact region that contacts the rim portion 400 and a non-contact region that does not contact the rim portion 400 are formed in the radially outer surface of the yoke 110 in the radial direction RD. In other words, the rotor 100 further includes a contact region, a first screw arrangement region S1, and a second screw arrangement region S2. The contact region is in the central region SS. That is, when viewed in the radial direction RD, the first screw arrangement region S1 and the second screw arrangement region S2 are in regions different from the contact region in the rotor 100. Note that "when viewed in the radial direction RD, the first screw arrangement region S1 and the second screw arrangement region S2 are in regions different from the contact region in the rotor 100" means that the contact region, the first screw arrangement region S1, and the second screw arrangement region S2 do not overlap when viewed in the radial direction RD.

[0050] Further, the entire radially inner surface of the first cylindrical portion 411 may contact the radially outer surface of the yoke 110, or a part of the radially inner surface of the first cylindrical portion 411 may contact the radially outer surface of the yoke 110. For example, the central portion of the first cylindrical portion 411 in the axial direction AD may protrude radially outward, and both end portions of the first cylindrical portion 411 in the axial direction AD may contact the radially outer surface of the yoke 110. In this case, the contact region may be a region 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.

[0051] Specifically, the contact region is arranged between the tip of the first screw 261 and the tip of the second screw 271 when viewed in the radial direction RD. Further, it is preferable that the contact region is arranged between the tip of the first cover screw hole 111 and the tip of the second cover screw hole 112 when viewed in the radial direction RD. Then, the radially inner surface of the first cylindrical portion 411 and the radially outer surface of the yoke 110 are welded.

[0052] When the tire is attached to the rim portion 400, one end portion of the tire in the one axial direction AD side (X direction) contacts the radially outer surface of the second cylindrical portion 412 and the other axial direction AD side of the second connecting portion 432. Further, one end portion of the tire in the other axial direction AD side (-X direction) contacts the radially outer surface of the fourth cylindrical portion 414 and the one axial direction AD side (X direction) of the fourth connecting portion 434.

[0053] As described above, according to the first embodiment, when viewed from the radial direction RD, there are a first screw arrangement region S1 and a second screw arrangement region S2 in a region different from the contact region in the rotor 100. As a result, when running, the load from the tire is applied to the contact region. 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, it is possible to provide the motor 10 that can suppress loosening of the first screw 261 and the second screw 271.

[0054] Further, since the contact region indicates a region where the radially outer surface of the yoke 110 and the rim portion 400 are in contact, it is possible to suppress the first screw 261 and the second screw 271 from coming out of the yoke 110.

[0055] Further, the contact region is disposed between the tip of the first screw 261 and the tip of the second screw 271 when viewed from the radial direction RD. That is, since the contact region is disposed at the center of the yoke 110, the yoke 110 and the rim portion 400 can be firmly fixed.

[0056] Further, since the contact region is disposed between the tip of the first cover screw hole 111 and the tip of the second cover screw hole 112 when viewed from the radial direction RD, the contact region can surely be prevented from overlapping the first screw 261 and the second screw 271.

[0057] Further, since the axial length AD of the first screw 261 and the axial length AD of the second screw 271 are the same, the types of the first screw 261 and the second screw 271 can be made the same. As a result, it is possible to suppress an increase in the types of parts.

[0058] Also, since each of the axial length AD of the first screw 261 and the axial length AD of the second screw 271 is shorter than half of the axial length AD of the yoke 110, it is possible to suppress a decrease in the area of the contact region.

[0059] And the rim portion 400 increases in size from the center in the axial direction AD of the rim portion 400 toward one side in the axial direction AD and also increases in size 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 central portion of the yoke 110, the yoke 110 and the rim portion 400 can be firmly fixed.

[0060] Furthermore, since the yoke 110 and the rim portion 400 are welded in the contact region, the yoke 110 and the rim portion 400 can be fixed more firmly.

[0061] Next, with reference to FIG. 6, an electric two-wheeler 1020 equipped with the motor 10 of the first embodiment will be described. FIG. 6 is a schematic diagram of an electric two-wheeler 1020 including the motor 10 according to the first embodiment.

[0062] As shown in FIG. 6, 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.

[0063] 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. Thus, the rear wheel 1024 is attached to the frame 1021.

[0064] The rear wheel 1024 is rotatably supported below the rear of the frame 1021. The rear wheel 1024 rotates in contact with the ground.

[0065] 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 motor 10 can assist in driving the electric two-wheeler 1020. Also, according to the first embodiment, when traveling, 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 area S1 and the second screw arrangement area S2. Thus, it is possible to suppress the load from the tire being applied to the first screw 261 and the second screw 271. As a result, it is possible to suppress the loosening of the first screw 261 and the second screw 271.

[0066] (Second Embodiment) Referring to FIG. 7, the motor 2010 according to the second embodiment of the present invention will be described. FIG. 7 is a cross-sectional view showing the configuration of the motor 2010 according to the second embodiment. The motor 10 according to the first embodiment is an outer rotor, whereas the motor 2010 according to the second embodiment is an inner rotor. Hereinafter, regarding the second embodiment, matters different from the first embodiment will be described, and descriptions of parts overlapping with the first embodiment will be omitted.

[0067] The motor stator 200 is a substantially cylindrical body. The motor stator 200 is located radially outward of the shaft 50 in the radial direction RD. Specifically, the motor stator 200 is arranged around the rotation axis AX extending along the axial direction AD. The motor stator 200 is fixed to the shaft 50.

[0068] The rotor 100 includes a yoke 1110, a magnet 1120, a first rotor housing 1260, a second rotor housing 1270, a brake mechanism 280, and bearings 1290, 1291.

[0069] The magnet 1120 is, for example, a permanent magnet. The magnet 1120 faces radially inward with respect to the motor stator 200.

[0070] The yoke 1110 is a substantially cylindrical body. The yoke 1110 is, for example, an iron member. The yoke 1110 is fixed to the inner surface in the radial direction RD of the magnet 1120.

[0071] The first rotor housing 1260 is a disk body provided with a through hole penetrating along the axial direction AD at the center. The first rotor housing 1260 is located on one side (+X direction) in the axial direction AD of the yoke 1110. The first rotor housing 1260 is fixed to the yoke 1110.

[0072] Also, the first rotor housing 1260 is rotatably arranged with respect to the shaft 50. Specifically, the first rotor housing 1260 includes a cylindrical portion 1262. The cylindrical portion 1262 houses the bearing 1290. The cylindrical portion 1262 is located on the outside in the radial direction RD of the bearing 1290. 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.

[0073] The bearing 1290 rotatably supports the first rotor housing 1260 with respect to the shaft 50. The bearing 1290 is arranged between the shaft 50 and the wall portion 1262a. The bearing 1290 is, for example, a ball bearing, a rolling bearing.

[0074] The second rotor housing 1270 includes a disk body provided with a through hole penetrating 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) in the axial direction AD of the yoke 1110.

[0075] 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 on the outside in the radial direction RD with respect to the motor stator 200.

[0076] The side surface portion 1271 is provided with screw holes 1111. The screw holes 1111 extend along the axial direction AD. The screw holes 1111 are provided on one side surface of the side surface portion 1271 in the axial direction AD. For example, eight screw holes 1111 are formed in the side surface portion 1271. The eight screw holes 1111 are arranged at equal intervals along the circumferential direction CD.

[0077] Further, the second rotor housing 1270 is arranged to be rotatable with respect 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 1262 is located outside the bearing 1290 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.

[0078] The bearing 1291 rotatably supports the second rotor housing 1270 with respect to the shaft 50. The bearing 1291 is arranged between the shaft 50 and the wall portion 1272a. The bearing 1291 is, for example, a ball bearing or a roller bearing.

[0079] Specifically, the outer end portion of the first rotor housing 260 in the radial direction RD is fixed to one side surface of the side surface portion 1271 of the second rotor housing 270 by a plurality of screws 1261. The screws 1261 are an example of a "fastening member". That is, a screw arrangement region S3 in which the screws 1261 are arranged is included in a region up to a predetermined distance from one side in the axial direction AD of the side surface portion 1271.

[0080] Further, the radially outer surface of the side surface portion 1271 of the second rotor housing 270 contacts the radially inner surface of the first cylindrical portion 411. Specifically, in the side surface portion 1271 of the second rotor housing 270, a contact region that contacts the rim portion 400 and a non-contact region that does not contact the rim portion 400 are formed. The screw arrangement region S3 is in the non-contact region. That is, when viewed in the radial direction RD, the screw arrangement region S3 is in a region different from the contact region in the second rotor housing 270. Then, the radially inner surface of the first cylindrical portion 411 and the radially outer surface of the side surface portion 1271 of the second rotor housing 270 are welded.

[0081] As described above, according to the second embodiment, when viewed in the radial direction RD, the screw arrangement region S3 is in a region different from the contact region in the second rotor housing 270. As a result, when traveling, the load from the tire is applied to the contact region. On the other hand, the load from the tire is not applied to the screw arrangement region S3. Therefore, it is possible to suppress the load from the tire from being applied to the screw 1261. As a result, it is possible to provide the motor 2010 that suppresses the loosening of the screw 1261.

[0082] 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 forms without departing from the gist thereof. The drawings schematically show each component mainly for easy understanding, and the thickness, length, number, etc. of each illustrated component are different from the actual ones for convenience of drawing creation. Further, 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.

[0083] Note that the present technology can have the following configuration.

[0084] (1) A fixing portion fixed to a fixed shaft extending along the axial direction, A rotating portion that rotates with respect to the fixed shaft, An annular rim portion fixed to the radially outer side of the rotating portion comprises The rotating part comprises a first rotor housing located on one side in the axial direction and rotatably arranged on the fixed shaft, and a second rotor housing located on the other side in the axial direction and rotatably arranged on the fixed shaft comprises The first rotor housing and the second rotor housing are fixed by a fastening member, The rotating part a contact area in contact with the rim part, and an arrangement area where the fastening member is arranged further comprises When viewed from the radial direction, the arrangement area is in a region different from the contact area in the rotating part, a motor.

[0085] (2) The fastening member comprises a first fastening member and a second fastening member, The rotating part further comprises a yoke located outside the fixed part in the radial direction, 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 area is the area where the rim part and the yoke are in contact, the motor according to (1).

[0086] (3) The first fastening member is attached from one side in the axial direction of the yoke, The second fastening member is attached from the other side in the axial direction of the yoke, The contact area is arranged between the tip of the first fastening member and the tip of the second fastening member when viewed from the radial direction, the motor according to (2).

[0087] (4) The yoke comprises a first screw hole to which the first fastening member is attached, and a second screw hole to which the second fastening member is attached comprises The contact area is disposed between the tip of the first screw hole and the tip of the second screw hole when viewed in the radial direction, the motor according to (2) or (3).

[0088] (5) The axial length of the first fastening member and the axial length of the second fastening member are the same, The contact area is located at the axial center of the yoke, the motor according to any one of (2) to (4).

[0089] (6) Each of the axial length of the first fastening member and the axial length of the second fastening member is shorter than half of the axial length of the yoke, the motor according to any one of (2) to (5).

[0090] (7) The rim portion increases from the axial center of the rim portion toward one side in the axial direction and increases from the axial center of the rim portion toward the other side in the axial direction, the motor according to any one of (2) to (6).

[0091] (8) At the contact area, the yoke and the rim portion are welded, the motor according to any one of (2) to (7).

[0092] (9) The motor according to any one of (1) to (8), a wheel and is provided with,

Explanation of reference numerals

[0093] 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 placement area

Claims

1. a fixed part fixed to a fixed shaft extending along the axial direction; a rotating part that rotates with respect to the fixed shaft; an annular rim part fixed to the outer side in the radial direction of the rotating part and comprising; the rotating part is a first rotor housing located on one side in the axial direction and rotatably arranged on the fixed shaft; a second rotor housing located on the other side in the axial direction and rotatably arranged on the fixed shaft and comprising; the first rotor housing and the second rotor housing are fixed by a fastening member; the rotating part is a contact area in contact with the rim part; an arrangement area where the fastening member is arranged and further comprising; a motor, wherein when viewed from the radial direction, the arrangement area is in a region different from the contact area in the rotating part.

2. The fastening member comprises a first fastening member and a second fastening member, the rotating part further comprises a yoke located outside the fixed part in the radial direction, 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 motor according to claim 1, wherein the contact area indicates an area where the rim part and the yoke are in contact.

3. The first fastening member is attached from one side in the axial direction of the yoke, the second fastening member is attached from the other side in the axial direction of the yoke, The motor according to claim 2, wherein the contact area is arranged between the tip of the first fastening member and the tip of the second fastening member when viewed from the radial direction.

4. The yoke is a first screw hole to which the first fastening member is attached; a second screw hole to which the second fastening member is attached and comprising; The motor according to claim 3, wherein the contact area is arranged between the tip of the first screw hole and the tip of the second screw hole when viewed from the radial direction.

5. The axial length of the first fastening member and the axial length of the second fastening member are the same, The motor according to claim 2, wherein the contact area is located at the center in the axial direction of the yoke.

6. Each of the axial length of the first fastening member and the axial length of the second fastening member is shorter than half of the axial length of the yoke, The motor according to claim 2.

7. The motor according to claim 2, wherein the rim portion increases in size from the axial center of the rim portion toward one side in the axial direction and also 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, wherein at the contact region, the yoke and the rim portion are welded together.

9. A motor according to any one of claims 1 to 8, a wheel, comprising: an electric vehicle, wherein the motor is attached to the wheel.

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