Motor and electric vehicle

Abstract

A motor (10) has a fixed portion (300), a rotating portion (100), and a rim portion (400). The rotating portion (100) rotates relative to the fixed portion (300). The rim portion (400) supports a tire. The rotating portion (100) has a yoke (110) having a yoke main body portion (113) of a cylindrical shape and a yoke side contact portion (114) provided on a radial direction (RD) outer side of the yoke main body portion (113), and a magnet (120) mounted to the yoke main body portion (113). The rim portion (400) has a rim side contact portion (411) in contact with the radial direction (RD) outer side of the yoke side contact portion (114). A length of the yoke side contact portion (114) in an axial direction (AD) is different from a length of the yoke main body portion (113) in the axial direction (AD), or a position of a center of the yoke side contact portion (114) in the axial direction (AD) is different from a position of a center of the yoke main body portion (113) in the axial direction (AD).

Description

Technical Field

[0001] This invention relates to motors and electric vehicles. Background Technology

[0002] Previously, wheels for straddle-type electric vehicles were known (see, for example, Patent Document 1). A wheel for a straddle-type electric vehicle includes: a rim portion supporting a tire; a hub portion located inside the rim portion; and a rear yoke portion located inside the hub portion and supporting a ferrite magnet. In the wheel described in Patent Document 1, the axial center positions of the rim portion, the hub portion, and the rear yoke portion are the same.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2013-126859 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In the wheel described in Patent Document 1, when the axial position of the rim portion is shifted to accommodate a braking mechanism or similar device, the yoke, such as the rear yoke portion, lacks a configuration for contacting the rim portion. Therefore, it is necessary to increase the axial length of both the hub portion and the axial length of the yoke. As a result, the weight of the yoke increases.

[0008] This disclosure was made in view of the above-mentioned problems, and its purpose is to provide a motor and electric vehicle that can achieve a lightweight yoke without increasing the size of the yoke.

[0009] Solution for solving the problem

[0010] An exemplary motor disclosed herein includes: a fixed portion, a rotating portion, and a rim portion. The rotating portion rotates relative to the fixed portion. The rim portion supports a tire. The rotating portion includes: a yoke having a cylindrical yoke body portion and a yoke-side contact portion disposed radially outward of the yoke body portion; and a magnet mounted on the yoke body portion. The rim portion has a rim-side contact portion that contacts the radially outward side of the yoke-side contact portion. The axial length of the yoke-side contact portion differs from the axial length of the yoke body portion, or the position of the axial center of the yoke-side contact portion differs from the position of the axial center of the yoke body portion.

[0011] An exemplary electric vehicle disclosed herein includes: a motor as described above; and wheels, wherein the motor is mounted on the wheels.

[0012] Invention Effects

[0013] According to the exemplary disclosure, a yoke-side contact portion is provided in the yoke body portion of the yoke, corresponding to the position of the rim portion relative to the yoke. As a result, the yoke can be lightweight without increasing its size. Attached Figure Description

[0014] Figure 1 This is a perspective view showing a motor according to a first embodiment of the present disclosure.

[0015] Figure 2 This is an exploded view showing the interior of the motor according to the first embodiment.

[0016] Figure 3 This is a cross-sectional view showing the configuration of the motor according to the first embodiment.

[0017] Figure 4 This is an enlarged cross-sectional view showing the configuration of the motor according to the first embodiment.

[0018] Figure 5 This is a schematic diagram of an electric two-wheeled vehicle equipped with the motor of the first embodiment.

[0019] Figure 6 This is an enlarged cross-sectional view showing the configuration of the motor according to the second embodiment of this disclosure.

[0020] Figure 7 This is an enlarged cross-sectional view showing the configuration of the motor according to the third embodiment of this disclosure.

[0021] Figure 8 This is an enlarged cross-sectional view showing the configuration of the motor according to the fourth embodiment of this disclosure. Detailed Implementation

[0022] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be noted that in the drawings, the same or equivalent parts are labeled with the same reference numerals without being described repeatedly.

[0023] For convenience, the central axis AX of the motor is sometimes referred to as (refer to...) Figure 1The direction is explained as horizontal. In the figures, 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 represents the upward direction, and the negative direction of the Z-axis represents the downward direction. However, the vertical direction, the upward direction, and the downward direction are determined for ease of explanation and do not need to be consistent with the vertical direction. Furthermore, the vertical direction is defined only for ease of explanation and does not limit the orientation of the motor during use or assembly. Moreover, the direction parallel to the central axis AX of the motor is abbreviated as "axial AD," and the radial and circumferential directions centered on the central axis AX of the motor are abbreviated as "radial RD" and "circumferential CD." It should be noted that in this specification, "parallel direction" also includes directions that are substantially parallel.

[0024] It should be noted that in this specification, the motor's central axis AX sometimes coincides with the rotor's central axis, but the motor's central axis AX may also not coincide with the rotor's central axis. Even when the motor's central axis AX does not coincide with the rotor's central axis, the rotor may still rotate around an imaginary central axis different from the motor's central axis AX.

[0025] In this specification, the direction along the central axis AX of the motor or the central axis of the rotor is sometimes described as axial. Therefore, in this specification, axial means the direction along the central axis AX, which is the center of rotation of the motor or the central axis, which is the center of rotation of the rotor.

[0026] (First Implementation)

[0027] First, refer to Figure 1 The motor 10 of the first embodiment of this disclosure will be described. Figure 1 This is a perspective view showing the motor 10 according to the first embodiment of this disclosure. Figure 1 As shown, the motor 10 includes a rotor 100, a fixed part 300, and a rim part 400. The rotor 100 is an example of a "rotating part".

[0028] As an example, motor 10 is mounted on the wheel of a four-wheeled or two-wheeled vehicle. Typically, motor 10 is used as an in-wheel motor mounted on the axle of a four-wheeled or two-wheeled vehicle.

[0029] The rim portion 400 supports a tire (not shown). The rim portion 400 is fixed to the radial RD outer side of the rotor 100.

[0030] Next, refer to Figure 1 and Figure 2 The motor 10 of the first embodiment will be described. Figure 2 This is an exploded view showing the interior of the motor 10 according to the first embodiment. Figure 1 and Figure 2As shown, the fixing part 300 includes a shaft 50, a motor stator 200, and a stator cage 250.

[0031] Shaft 50 is approximately cylindrical. Shaft 50 is centered on a central axis AX extending along the axial direction AD. In the case of an in-wheel motor, shaft 50 is a fixed shaft, constituting the axle.

[0032] The motor stator 200 is generally cylindrical. The motor stator 200 is located radially outside the shaft 50. Specifically, the motor stator 200 is centered on a central axis AX extending along the axial direction AD. The motor stator 200 is fixed to the shaft 50. Furthermore, the motor stator 200 is located radially inside the rotor 100.

[0033] Rotor 100 is a generally cylindrical body. Rotor 100 is located radially outside the fixed part 300. Specifically, rotor 100 is centered on a central axis AX extending along the axial direction AD. Rotor 100 surrounds the radially outside the fixed part 300. Rotor 100 rotates relative to shaft 50 about the central axis AX. Such a rotor 100 is also referred to as an outer rotor.

[0034] The motor stator 200 includes a stator core 210, an insulator 220, a coil 230, and an insulating plate 240.

[0035] The stator core 210 is centered on a central axis AX extending along the axial direction AD. As an example, the stator core 210 is approximately annular with the central axis AX as its center. "Approximately annular" means, for example, approximately circular. The stator core 210 is, for example, composed of laminated steel plates formed by stacking thin electromagnetic steel plates along the axial direction AD.

[0036] The stator core 210 has a core back and multiple teeth. The multiple teeth extend from the outer radial direction RD of the core back to the outer radial direction RD. The multiple teeth are arranged at equal intervals along the circumferential direction CD.

[0037] Insulator 220 covers at least a portion of stator core 210. As an example, insulator 220 surrounds stator core 210 from both sides of axial direction AD. Insulator 220 is generally annular. "Generally annular" is, for example, "generally circular." Insulator 220 is an electrical insulator. Insulator 220 electrically insulates stator core 210 from coil 230. Insulator 220 can be composed of a single component or multiple different components. For example, insulator 220 is a resin-molded article into which stator core 210 is embedded. Furthermore, insulator 220 can also be a separately mounted structure relative to stator core 210.

[0038] Coil 230 is wound around stator core 210 with an insulator 220 in between. Coil 230 is a covered conductor made of metal wire covered by a coating. The raw material of the metal wire is, for example, copper. However, the raw material of the metal wire can also be aluminum instead of copper. The coating covering the metal wire is, for example, an insulating resin.

[0039] The stator cage 250 is a circular plate with a through hole extending along the axial direction AD at its center. The motor stator 200 is disposed at the radially outer end of the stator cage 250. For example, the shaft 50 is pressed into the through hole to fix the shaft 50 to the stator cage 250. At this time, the shaft 50 protrudes from the outside of the stator cage 250. The shaft 50 extends from the stator cage 250 along the central axis AX towards the axial direction AD (+X direction). In addition, the shaft 50 extends from the stator cage 250 along the central axis AX towards the other side of the axial direction AD (-X direction).

[0040] The insulating plate 240 is formed, for example, of an insulating resin. The insulating plate 240 is disposed between the stator cage 250 and the motor stator 200. The insulating plate 240 is generally cylindrical. It should be noted that the insulating plate 240 and the insulating element 220 can also be integrally formed.

[0041] The rotor 100 includes a yoke 110 and magnets 120. Magnets 120 are, for example, permanent magnets. Magnets 120 are positioned radially outward relative to the motor stator 200. For example, the rotor 100 may have a single, generally annular magnet 120, or multiple magnets 120 arranged circumferentially along the CD. "Generally annular" is, for example, "generally circular." The multiple magnets 120 are arranged with alternating N and S poles along the circumferential CD. For example, the number of poles of the magnets 120 is "60." However, the number of poles of the magnets 120 is not limited to this.

[0042] The yoke 110 is a generally cylindrical body. The yoke 110 is, for example, an iron component. A magnet 120 is mounted on the yoke 110. Specifically, the yoke 110 is fixed to the radially RD outer surface of the magnet 120. It should be noted that the magnet 120 can also be disposed inside the yoke 110.

[0043] Next, refer to Figures 1 to 4 The motor 10 of the first embodiment will be described. Figure 3 This is a cross-sectional view showing the configuration of the motor 10 according to the first embodiment. Figure 4 This is an enlarged cross-sectional view showing the configuration of the motor 10 according to the first embodiment. It should be noted that... Figure 3 yes, Figure 4 This is a cross-sectional view obtained by cutting the line connecting the second cover threaded hole 112 to the second cover threaded hole 112. For example... Figures 1 to 4 As shown, the rim portion 400 is fixed to the radial RD outer side of the rotor 100.

[0044] The rim portion 400 is an annular component surrounding the outer periphery of the rotor 100. A tire is mounted on the rim portion 400. For example, the material of the rim portion 400 is iron or aluminum, preferably the same material as the magnetic yoke 110.

[0045] 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 first cylindrical portion 411 is an example of a "rim-side contact portion". The second cylindrical portion 412, the third cylindrical portion 413, the fourth cylindrical portion 414, the fifth cylindrical portion 415, the first connecting portion 431, the second connecting portion 432, the third connecting portion 433, and the fourth connecting portion 434 are examples of "rim flange portions". In the axial direction AD, the length of the first cylindrical portion 411 is a first distance L1.

[0046] The second cylindrical portion 412 is connected to the other side (-X direction) of the first cylindrical portion 411 along the axial AD direction via the first connecting portion 431. The third cylindrical portion 413 is connected to the other side (-X direction) of the second cylindrical portion 412 along the axial AD direction via the second connecting portion 432. The fourth cylindrical portion 414 is connected to one side (X direction) of the first cylindrical portion 411 along the axial AD direction via the third connecting portion 433. The fifth cylindrical portion 415 is connected to one side (X direction) of the fourth cylindrical portion 414 along the axial AD direction via the fourth connecting portion 434.

[0047] In detail, the rim portion 400 protrudes radially RD from both ends of the first cylindrical portion 411 along the axial direction AD. The rim portion 400 increases in size from the center of the rim portion 400 along the axial direction AD to one side, and from the center of the rim portion 400 along the axial direction AD to the other side. 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.

[0048] Furthermore, the radially RD outer surface of the magnetic yoke 110 contacts the radially RD inner surface of the first cylindrical portion 411. Specifically, the radially RD inner surface of the first cylindrical portion 411 and the radially RD outer surface of the magnetic yoke 110 are pressed together and welded.

[0049] It should be noted that the entire inner radial surface of the first cylindrical portion 411 may contact the outer radial surface of the magnetic yoke 110, or only a portion of the inner radial surface of the first cylindrical portion 411 may contact the outer radial surface of the magnetic yoke 110. For example, the central portion of the first cylindrical portion 411 on the axial direction AD may protrude outward on the radial direction RD, and both ends of the first cylindrical portion 411 on the axial direction AD may contact the outer radial surface of the magnetic yoke 110.

[0050] When the tire is mounted on the rim portion 400, the end of the tire on the other side of the axial AD direction (-X direction) contacts the outer radial RD side surface of the second cylindrical portion 412 and the axial AD side surface of the second connecting portion 432. In addition, the end of the tire on the axial AD side (X direction) contacts the outer radial RD side surface of the fourth cylindrical portion 414 and the other side of the axial AD direction (-X direction) of the fourth connecting portion 434.

[0051] The magnetic yoke 110 includes a main body portion 113 and a side contact portion 114. The main body portion 113 and the side contact portion 114 are a single component. As a result, it is not necessary to fix the main body portion 113 and the side contact portion 114 by welding or the like, and it can better withstand impacts from the rim portion 400 compared to fixing different components together.

[0052] The main body 113 of the magnetic yoke is cylindrical in shape. The length of the main body 113 of the magnetic yoke along the axial direction AD is the second distance L2.

[0053] The magnetic yoke body 113 has a first cover threaded hole 111 and a second cover threaded hole 112. The first cover threaded hole 111 and the second cover threaded hole 112 extend along the axial direction AD, respectively.

[0054] The first cover threaded hole 111 is provided on the other side of the magnetic yoke body 113 along the axial direction AD. For example, eight first cover threaded holes 111 are formed in the magnetic yoke body 113. The eight first cover threaded holes 111 are arranged at equal intervals along the circumferential direction CD.

[0055] The second cover threaded hole 112 is provided on one side of the magnetic yoke body 113 along the axial direction AD. For example, eight second cover threaded holes 112 are formed on the magnetic yoke 110. The eight second cover threaded holes 112 are arranged at equal intervals along the circumferential direction CD. It should be noted that the first cover threaded hole 111 and the second cover threaded hole 112 are arranged alternately along the circumferential direction CD.

[0056] A yoke-side contact portion 114 is provided on the radially RD outer side of the yoke body portion 113. Specifically, corresponding to the position of the rim portion 400 relative to the yoke 110, a yoke-side contact portion 114 is provided on the yoke body portion 113 of the yoke 110. For example, the yoke-side contact portion 114 has a cylindrical shape located on the radially RD outer side of the yoke body portion 113. In the axial direction AD, the length of the yoke-side contact portion 114 is a third distance L3.

[0057] The magnetic yoke-side contact portion 114 in the first embodiment includes a protrusion 114a and a connecting portion 114b.

[0058] The protrusion 114a protrudes from the magnetic yoke body 113 toward the axial direction AD. The protrusion 114a is cylindrical in shape. Along the axial direction AD, the length of the protrusion 114a is the fourth distance L4.

[0059] The connecting portion 114b is connected to the radially RD outer side of the yoke body portion 113. The connecting portion 114b is cylindrical in shape. The length of the connecting portion 114b along the axial direction AD is a fifth distance L5. A protrusion 114a is disposed on one side of the connecting portion 114b along the axial direction AD. Furthermore, the end face of the yoke-side contact portion 114 along the axial direction AD is connected to the outer peripheral surface of the yoke body portion 113. Specifically, the other side of the connecting portion 114b along the axial direction AD is connected to the outer peripheral surface of the yoke body portion 113. In other words, a stepped shape is formed on the outer peripheral surface of the yoke 110. As a result, compared to the case where the outer peripheral surface of the yoke 110 is a uniform surface, a lighter yoke can be achieved.

[0060] The axial AD length L5 of the connecting portion 114b is longer than the axial AD length L4 of the protrusion 114a. In other words, the area of ​​the connecting portion 114b connected to the radial RD outer side of the magnetic yoke body portion 113 can be increased. As a result, it can better withstand impacts from the rim portion 400.

[0061] In the yoke 110, the length L3 of the axial AD of the yoke-side contact portion 114 is different from the length L2 of the axial AD of the yoke body portion 113, or the position of the center of the axial AD of the yoke-side contact portion 114 is different from the position of the center of the axial AD of the yoke body portion 113. Specifically, in the yoke 110 of the first embodiment, the length L3 of the axial AD of the yoke-side contact portion 114 is different from the length L2 of the axial AD of the yoke body portion 113, and the position of the center of the axial AD of the yoke-side contact portion 114 is different from the position of the center of the axial AD of the yoke body portion 113.

[0062] As described above, according to the first embodiment, for example, the position or length L1 of the axial AD of the first cylindrical portion 411 differs from the position or length L2 of the axial AD of the yoke body portion 113, but a yoke-side contact portion 114 is provided on the yoke 110. In other words, the yoke-side contact portion 114 is provided on the yoke 110 corresponding to the position or length L1 of the first cylindrical portion 411 relative to the yoke 110. As a result, compared to a cylindrical yoke, the yoke 110 can be made lighter without increasing its size.

[0063] Furthermore, the magnetic yoke side contact portion 114 is cylindrical in shape and located on the radial outer side of the magnetic yoke body portion 113. Therefore, the magnetic yoke side contact portion 114 is connected to the rim portion 400 around the circumference CD, which can further improve the fixing strength between the magnetic yoke 110 and the rim portion 400.

[0064] Specifically, the length L3 of the axial AD of the yoke-side contact portion 114 is more than half the length L1 of the axial AD of the first cylindrical portion 411. As a result, deformation of the first cylindrical portion 411 can be suppressed. In the first embodiment, the length L3 of the axial AD of the yoke-side contact portion 114 is the same as the length of the axial AD of the first cylindrical portion 411.

[0065] Next, refer to Figures 1 to 4 The rotor 100 will be described below. Figures 1 to 4 As shown, the rotor 100 also includes a first rotor housing 260, a second rotor housing 270, a braking mechanism 280, and bearings 290 and 291. The first rotor housing 260 and the second rotor housing 270 are examples of a "cover member".

[0066] The first rotor housing 260 is a circular plate with a through hole extending along the axial direction AD at its center. The first rotor housing 260 is located on the other side of the magnetic yoke 110 along the axial direction AD (-X direction). The first rotor housing 260 covers at least a portion of the motor stator 200 and rotor 100 from the other side of the axial direction AD. The first rotor housing 260 is fixed to the magnetic yoke 110.

[0067] Specifically, the radially RD outer end of the first rotor housing 260 is fixed to the other side of the axial AD of the magnetic yoke body 113 by a plurality of first screws 261. Specifically, the first screws 261 are installed from the other side of the axial AD of the magnetic yoke body 113 into the first cover threaded hole 111. For example, the number of the plurality of first screws 261 can be "8", but is not limited thereto.

[0068] Furthermore, the first rotor housing 260 is configured to rotate 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. The cylindrical portion 262 surrounds the shaft 50 and extends axially along the AD.

[0069] The bearing 290 supports the first rotor housing 260 for rotation relative to the shaft 50. The bearing 290 is disposed between the shaft 50 and the cylinder portion 262. The bearing 290 is, for example, a ball bearing or a rolling bearing.

[0070] The second rotor housing 270 is a circular plate with a through hole extending along the axial direction AD at its center. The second rotor housing 270 is located on the axial direction AD side (X direction) of the magnetic yoke 110. The second rotor housing 270 covers at least a portion of the motor stator 200 and rotor 100 from the axial direction AD side. The second rotor housing 270 is fixed to the magnetic yoke 110.

[0071] Specifically, the radially RD outer end of the second rotor housing 270 is fixed to the axially AD side of the magnetic yoke body 113 by a plurality of second screws 271. Specifically, the second screws 271 are installed from the axially AD side of the magnetic yoke body 113 into the threaded hole 112 of the second cover. For example, the number of the plurality of second screws 271 is "8".

[0072] The second rotor housing 270 is located radially inside the protrusion 114a. As a result, the mounting position of the second rotor housing 270 can be configured on the central side of the rim portion 400, reducing the overall axial length AD of the motor 10. Furthermore, the presence of a yoke-side contact portion 114 between the second cover threaded hole 112 and the rim portion 400 suppresses the transmission of vibrations from the tire to the second screw 271.

[0073] Furthermore, the second rotor housing 270 is configured to rotate relative to the shaft 50. Specifically, the second rotor housing 270 includes a cylindrical portion 272. The cylindrical portion 272 houses the bearing 291. The cylindrical portion 272 is located radially outside the bearing 291. The cylindrical portion 272 surrounds the shaft 50 and extends axially along the axis AD.

[0074] The bearing 291 supports the second rotor housing 270 for rotation relative to the shaft 50. The bearing 291 is disposed between the shaft 50 and the cylinder portion 272. The bearing 291 is, for example, a ball bearing or a rolling bearing.

[0075] The braking mechanism 280 is generally cylindrical. The braking mechanism 280 is located radially outward relative to the shaft 50. Specifically, the braking mechanism 280 is centered on a central axis AX extending along the axial direction AD. The braking mechanism 280 is fixed to the second rotor housing 270.

[0076] It should be noted that the inner end of the rotor 100 on the radial RD side is not covered by the first rotor housing 260 and the second rotor housing 270 and is directly opposite the motor stator 200. The motor stator 200 is disposed between the first rotor housing 260 and the second rotor housing 270.

[0077] 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 control signals for the U-phase, V-phase, and W-phase. When the control signals for the U-phase, V-phase, and W-phase are input to the motor stator 200, the rotor 100 rotates in response to changes in the magnetic field generated in the motor stator 200. This three-phase AC power is supplied from an electric two-wheeled vehicle 1020 (see reference 1020). Figure 5 The inverter device (not shown) is connected to the motor stator 200 via power lines (not shown). The power lines (not shown) pass through a through hole (not shown) provided on the shaft 50 and are connected to the motor stator 200.

[0078] The third connecting portion 433 has a through hole 440 connecting the inner radial side RD to the outer radial side RD. Specifically, the through hole 440 is provided on the third connecting portion 433 on the axial AD side of the first cylindrical portion 411. As a result, when the valve 441 is provided in the through hole 440, air can enter the tire from the inner radial side RD of the third connecting portion 433 through the through hole 440 without being obstructed by the magnetic yoke 110.

[0079] Next, refer to Figure 5 The electric two-wheeled vehicle 1020 equipped with the motor 10 of the first embodiment will be described. Figure 5 This is a schematic diagram of an electric two-wheeled vehicle 1020 equipped with the motor 10 of the first embodiment.

[0080] like Figure 5 As shown, motor 10 is mounted on electric two-wheeler 1020. Examples of electric two-wheelers include electric scooters and electric motorcycles. For example, motor 10 drives the wheels of electric two-wheeler 1020.

[0081] Motor 10 is mounted on electric two-wheeler 1020. In addition to motor 10, electric two-wheeler 1020 also includes frame 1021, handlebars 1022, front wheel 1023, rear wheel 1024, and seat 1025. Rear wheel 1024 is an example of a "wheel". For example, motor 10 is mounted on rear wheel 1024. Furthermore, the axle 50 of motor 10 is mounted on frame 1021. Therefore, rear wheel 1024 is mounted on frame 1021.

[0082] The rear wheel 1024 is rotatably supported at the rear under the frame 1021. The rear wheel 1024 rotates in contact with the ground.

[0083] In the first embodiment, the axial length AD of the entire motor 10 can be reduced.

[0084] (Second Implementation)

[0085] Reference Figure 6 The motor 2010 of the second embodiment of the present invention will be described. Figure 6 This is an enlarged cross-sectional view showing the configuration of the motor 2010 according to the second embodiment. The motor 10 of the first embodiment includes a yoke-side contact portion 114, while the motor 2010 of the second embodiment includes a yoke-side contact portion 2114. Hereinafter, the differences between the second embodiment and the first embodiment will be described, and descriptions of parts that are repeated in the first embodiment will be omitted.

[0086] The magnetic yoke 110 includes a main body 113 and a side contact portion 2114. The main body 113 and the side contact portion 2114 are a single component. As a result, the main body 113 and the side contact portion 2114 do not need to be fixed by welding or the like, and can withstand impacts from the rim portion 400 more strongly compared to fixing different components together.

[0087] A yoke-side contact portion 2114 is provided on the radially RD outer side of the yoke body portion 113. Specifically, corresponding to the position of the rim portion 400 relative to the yoke 110, the yoke-side contact portion 2114 is provided on the yoke body portion 113 of the yoke 110. For example, the yoke-side contact portion 2114 is cylindrical in shape and located on the radially RD outer side of the yoke body portion 113. In the axial direction AD, the length of the yoke-side contact portion 2114 is a third distance L3.

[0088] The end face of the axial AD of the yoke-side contact portion 2114 is connected to the outer peripheral surface of the yoke body portion 113. Specifically, the other side of the axial AD of the yoke-side contact portion 2114 is connected to the outer peripheral surface of the yoke body portion 113. In other words, a stepped shape is formed on the outer peripheral surface of the yoke 110. As a result, compared with the case where the outer peripheral surface of the yoke 110 is a uniform surface, the yoke can be made lighter.

[0089] In the yoke 110, the length L3 of the axial AD of the yoke-side contact portion 2114 is different from the length L2 of the axial AD of the yoke body portion 113, or the position of the center of the axial AD of the yoke-side contact portion 2114 is different from the position of the center of the axial AD of the yoke body portion 113. Specifically, in the yoke 110 of the second embodiment, the length L3 of the axial AD of the yoke-side contact portion 2114 is different from the length L2 of the axial AD of the yoke body portion 113, and the position of the center of the axial AD of the yoke-side contact portion 2114 is different from the position of the center of the axial AD of the yoke body portion 113.

[0090] As described above, according to the second embodiment, for example, the position or length L1 of the axial AD of the first cylindrical portion 411 differs from the position or length L2 of the axial AD of the yoke body portion 113, but a yoke-side contact portion 2114 is provided on the yoke 110. In other words, the yoke-side contact portion 2114 is provided on the yoke 110 corresponding to the position or length L1 of the first cylindrical portion 411 relative to the yoke 110. As a result, compared with a cylindrical yoke, the yoke 110 can be made lighter without increasing its size.

[0091] (Third Implementation)

[0092] Reference Figure 7 The motor 3010 of the third embodiment of the present invention will be described. Figure 7 This is an enlarged cross-sectional view showing the configuration of the motor 3010 according to the third embodiment. The motor 10 of the first embodiment includes a yoke-side contact portion 114, while the motor 3010 of the third embodiment includes a yoke-side contact portion 3114. Hereinafter, the differences between the third embodiment and the first embodiment will be described, and descriptions of parts that overlap with the first embodiment will be omitted.

[0093] The magnetic yoke 110 includes a main body portion 113 and a side contact portion 3114. The main body portion 113 and the side contact portion 3114 are a single component. As a result, it is not necessary to fix the main body portion 113 and the side contact portion 3114 by welding or the like, and it can better withstand impacts from the rim portion 400 compared to fixing different components together.

[0094] A yoke-side contact portion 3114 is provided on the radially RD outer side of the yoke body portion 113. Specifically, corresponding to the position of the rim portion 400 relative to the yoke 110, a yoke-side contact portion 3114 is provided on the yoke body portion 113 of the yoke 110. For example, the yoke-side contact portion 3114 is cylindrical in shape and located on the radially RD outer side of the yoke body portion 113. In the axial direction AD, the length of the yoke-side contact portion 3114 is a sixth distance L6.

[0095] Specifically, the length L6 of the axial AD of the yoke-side contact portion 3114 is more than half the length L1 of the axial AD of the first cylindrical portion 411. As a result, deformation of the first cylindrical portion 411 can be suppressed. In the third embodiment, the length L6 of the axial AD of the yoke-side contact portion 3114 is longer than the length of the axial AD of the first cylindrical portion 411.

[0096] The end face of the axial AD of the yoke-side contact portion 3114 is connected to the outer peripheral surface of the yoke body portion 113. Specifically, the other side of the axial AD of the yoke-side contact portion 3114 is connected to the outer peripheral surface of the yoke body portion 113. In other words, a stepped shape is formed on the outer peripheral surface of the yoke 110. As a result, compared with the case where the outer peripheral surface of the yoke 110 is a uniform surface, the yoke can be made lighter.

[0097] In the yoke 110, the length L6 of the axial AD of the yoke-side contact portion 3114 is different from the length L2 of the axial AD of the yoke body portion 113, or the position of the center of the axial AD of the yoke-side contact portion 3114 is different from the position of the center of the axial AD of the yoke body portion 113. Specifically, in the yoke 110 of the third embodiment, the length L6 of the axial AD of the yoke-side contact portion 3114 is different from the length L2 of the axial AD of the yoke body portion 113, and the position of the center of the axial AD of the yoke-side contact portion 3114 is different from the position of the center of the axial AD of the yoke body portion 113.

[0098] As described above, according to the third embodiment, for example, the position or length L1 of the axial AD of the first cylindrical portion 411 differs from the position or length L2 of the axial AD of the yoke body portion 113, but a yoke-side contact portion 3114 is provided on the yoke 110. In other words, the yoke-side contact portion 3114 is provided on the yoke 110 corresponding to the position or length L1 of the first cylindrical portion 411 relative to the yoke 110. As a result, compared with a cylindrical yoke, the yoke 110 can be made lighter without increasing its size.

[0099] (Fourth Implementation)

[0100] Reference Figure 8 The motor 4010 of the fourth embodiment of the present invention will be described. Figure 8 This is an enlarged cross-sectional view showing the configuration of the motor 4010 according to the fourth embodiment. The motor 10 of the first embodiment includes a yoke-side contact portion 114, while the motor 4010 of the fourth embodiment includes a yoke-side contact portion 4114. Hereinafter, the differences between the fourth embodiment and the first embodiment will be described, and descriptions of parts that are repeated in the first embodiment will be omitted.

[0101] The magnetic yoke 110 includes a main body 113 and a side contact portion 4114. The main body 113 and the side contact portion 4114 are a single component. As a result, the main body 113 and the side contact portion 4114 do not need to be fixed by welding or the like, and can withstand impacts from the rim portion 400 more strongly compared to fixing different components together.

[0102] A yoke-side contact portion 4114 is provided on the radially RD outer side of the yoke body portion 113. Specifically, corresponding to the position of the rim portion 400 relative to the yoke 110, a yoke-side contact portion 4114 is provided on the yoke body portion 113 of the yoke 110. For example, the yoke-side contact portion 4114 has a cylindrical shape located on the radially RD outer side of the yoke body portion 113. In the axial direction AD, the length of the yoke-side contact portion 4114 is a seventh distance L7.

[0103] The end face of the axial AD of the yoke-side contact portion 4114 is connected to the outer peripheral surface of the yoke body portion 113. Specifically, the other side of the axial AD of the yoke-side contact portion 4114 is connected to the outer peripheral surface of the yoke body portion 113. Furthermore, the other side of the axial AD of the yoke-side contact portion 4114 is connected to the outer peripheral surface of the yoke body portion 113. In other words, a stepped shape is formed on the outer peripheral surface of the yoke 110, corresponding to the position of the rim portion 400 relative to the yoke 110. As a result, compared to the case where the outer peripheral surface of the yoke 110 is a uniform surface, the yoke can be made lighter.

[0104] In the yoke 110, the length L7 of the axial AD of the yoke-side contact portion 4114 is different from the length L2 of the axial AD of the yoke body portion 113, or the position of the center of the axial AD of the yoke-side contact portion 4114 is different from the position of the center of the axial AD of the yoke body portion 113. Specifically, in the yoke 110 of the fourth embodiment, the length L7 of the axial AD of the yoke-side contact portion 4114 is different from the length L2 of the axial AD of the yoke body portion 113, and the position of the center of the axial AD of the yoke-side contact portion 4114 is the same as the position of the center of the axial AD of the yoke body portion 113.

[0105] As described above, according to the fourth embodiment, for example, the position or length L1 of the axial AD of the first cylindrical portion 411 differs from the position or length L2 of the axial AD of the yoke body portion 113, but a yoke-side contact portion 4114 is provided on the yoke 110. In other words, corresponding to the position or length L1 of the first cylindrical portion 411 relative to the yoke 110, a yoke-side contact portion 4114 is provided on the yoke 110. As a result, compared to a cylindrical yoke, the yoke 110 can be made lighter without increasing its size.

[0106] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described above, and can be implemented in various ways without departing from its spirit. For ease of understanding, the accompanying drawings are schematically shown with each constituent element as the main body, and the thickness, length, number, etc. of each constituent element shown may differ from the actual figures for ease of drawing production. Furthermore, the material, shape, size, etc. of each constituent element shown in the above embodiments are examples and are not particularly limited; of course, various modifications can be made without substantially departing from the effects of the present invention.

[0107] It should be noted that this technology can have the following configuration.

[0108] (1) A motor comprising: a fixed portion; a rotating portion that rotates relative to the fixed portion; and a rim portion that supports a tire, the rotating portion comprising: a yoke having a cylindrical yoke body portion and a yoke-side contact portion disposed radially outward of the yoke body portion; and a magnet mounted on the yoke body portion, the rim portion having a rim-side contact portion that contacts the radially outward of the yoke-side contact portion, the axial length of the yoke-side contact portion being different from the axial length of the yoke body portion, or the position of the axial center of the yoke-side contact portion being different from the position of the axial center of the yoke body portion.

[0109] (2) The motor according to (1), wherein the axial end face of the magnetic yoke side contact portion is connected to the outer peripheral surface of the magnetic yoke body portion.

[0110] (3) The motor according to (1) or (2), wherein the axial length of the magnetic yoke side contact portion is more than half the axial length of the rim side contact portion.

[0111] (4) The motor according to any one of (1) to (3), wherein the shape of the magnetic yoke side contact portion is a cylindrical shape provided on the radially outer side of the magnetic yoke body portion.

[0112] (5) The motor according to any one of (1) to (4), wherein the motor further comprises a cover member mounted on an end of the axial side of the yoke body, the yoke side contact portion comprising: a protrusion that protrudes from the yoke body to an axial side; and a connecting portion that is connected to the radially outer side of the yoke body, the cover member being located radially inner than the protrusion.

[0113] (6) The motor according to (5) wherein a threaded hole for screw insertion is provided at the end of the axial side of the magnetic yoke body, and the cover member is fixed to the magnetic yoke body by the screw.

[0114] (7) The motor according to any one of (1) to (6), wherein the axial length of the connecting portion is longer than the axial length of the protrusion.

[0115] (8) The motor according to any one of (1) to (7), wherein the yoke body portion and the yoke side contact portion are a single component.

[0116] (9) The motor according to any one of (1) to (8), wherein the rim portion further comprises a rim flange portion that protrudes radially from both ends of the axial direction of the rim side contact portion, the rim flange portion comprising a through hole connecting the radial inner side and the radial outer side, the through hole being provided on the rim flange portion provided on one side of the axial direction of the rim side contact portion.

[0117] (10) An electric vehicle comprising: a motor as described in any one of (1) to (9); and wheels, wherein the motor is mounted on the wheels.

[0118] Explanation of reference numerals in the attached figures

[0119] 10: Motor; 50: Shaft; 100: Rotor (rotating part); 110: Magnetic yoke; 113: Magnetic yoke main body; 114: Magnetic yoke side contact part; 120: Magnet (magnetic body); 200: Motor stator; 260: First rotor housing; 261: First screw; 270: Second rotor housing; 300: Motor part (fixed part); 400: Rim part; 411: Rim side contact part; AD: Axial; RD: Radial.

Claims

1. A motor, said motor comprising: Fixing part; The rotating part rotates relative to the fixed part; and The rim section, which supports the tire, The rotating part includes: A magnetic yoke, comprising a cylindrical yoke body and a yoke-side contact portion located radially outward of the yoke body; and A magnet, which is mounted on the main body of the magnetic yoke, The rim portion has a rim-side contact portion that contacts the radially outer side of the magnetic yoke-side contact portion. The axial length of the magnetic yoke side contact portion is different from the axial length of the magnetic yoke body portion, or the position of the axial center of the magnetic yoke side contact portion is different from the position of the axial center of the magnetic yoke body portion.

2. The motor according to claim 1, wherein, The axial end face of the magnetic yoke side contact portion is connected to the outer peripheral surface of the magnetic yoke body portion.

3. The motor according to claim 1, wherein, The axial length of the magnetic yoke side contact portion is more than half the axial length of the rim side contact portion.

4. The motor according to claim 1, wherein, The shape of the magnetic yoke side contact portion is a cylindrical shape located radially outward of the magnetic yoke body.

5. The motor according to claim 1, wherein, The motor also includes a cover member installed at one end of the axial side of the magnetic yoke body. The magnetic yoke-side contact portion includes: A protrusion that protrudes axially from the main body of the magnetic yoke; and The connecting part is connected to the radially outer side of the main body of the magnetic yoke. The cover component is located radially inward than the protrusion.

6. The motor according to claim 5, wherein, A threaded hole for screw insertion is provided at one end of the axial side of the magnetic yoke body. The cover component is fixed to the magnetic yoke body by the screw.

7. The motor according to claim 5, wherein, The axial length of the connecting portion is longer than the axial length of the protrusion.

8. The motor according to claim 1, wherein, The main body of the yoke and the side contact portion of the yoke are a single component.

9. The motor according to claim 1, wherein, The rim portion also includes rim flange portions that project radially from both ends of the axial direction of the rim-side contact portion. The rim flange has a through hole connecting the radially inner side and the radially outer side. The through hole is provided on the rim flange portion located on the axial side of the contact portion of the rim side.

10. An electric vehicle, said electric vehicle comprising: The motor according to any one of claims 1 to 9; and wheel, The motor is mounted on the wheel.

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