Electric vehicle

Abstract

An electric vehicle (10) is provided with a swing arm (14) that is pivotally supported by a pivot shaft (28) provided to a vehicle body frame (18) and that supports a rear wheel (12R) at the other end. A case (32) of the swing arm (14) has a motor accommodation part (36) that opens outward in the vehicle width direction of the vehicle body frame (18) and accommodates a motor (16). A stator (58) of the motor (16) is fixed to a cover part (34) that covers an opening (40) of the motor accommodation part (36), and a control device (24) is disposed between the stator (58) and the cover part (34).

Description

Electric vehicles

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

[0002] In recent years, efforts to realize a low-carbon or carbon-free society have become more active, and research and development into electrification technology has been conducted to reduce CO2 emissions and improve energy efficiency in vehicles. International Publication No. 2021 / 199165 discloses an electric vehicle in which a motor is disposed on the side of the rear wheel to drive the rear wheel. In the electric vehicle, the motor is attached together with a reduction gear to a swing arm case that is swingably mounted relative to the vehicle body. The rear wheel is rotatably supported at the rear end of the swing arm, and the driving force of the motor is transmitted to the rear wheel shaft via the reduction gear.

[0003] International Publication No. 2021 / 065451 discloses a motor having a control device disposed at one axial end of a rotating shaft. The control device is accommodated inside a housing constituting the motor and fixed to the housing via a substrate. The control device controls the drive of the motor.

[0004] However, in motors for electric vehicles such as those disclosed in International Publication No. 2021 / 065451, which relates to electrification technology, the control device is attached to the axial end of the housing, resulting in variations in the mounting position of the control device in the axial direction of the motor. Therefore, when the motor of International Publication No. 2021 / 065451 is housed and assembled in the swing arm case of International Publication No. 2021 / 199165 together with a reducer, the gap between the cover provided on the outside of the control device in the axial direction of the motor and the control device becomes large, resulting in a problem of reduced heat dissipation from the control device. Solving this problem will contribute to improving energy efficiency.

[0005] The present invention aims to solve the above-mentioned problems.

[0006] One aspect of the present invention is an electric vehicle comprising a body frame, a pivot shaft provided on the body frame, a swing arm having one end journalled on the pivot shaft and the other end supporting a rear wheel, a motor disposed on the swing arm for driving the rear wheel, and a control device for controlling the drive of the motor, wherein the swing arm has a motor housing portion that opens outward in the vehicle width direction of the body frame, and comprises a case in which the motor is housed in the motor housing portion, and a cover portion that covers the opening of the motor housing portion, a stator of the motor is fixed to the cover portion, and the control device is disposed between the stator and the cover portion.

[0007] According to the present invention, compared to a configuration in which the motor stator is fixed to the swing arm case, fixing the stator to the cover can suppress dimensional variations between the cover and the stator, thereby reducing the gap between the cover and the control device disposed between the cover and the stator, thereby effectively improving the heat dissipation of the control device.

[0008] Fig. 1 is a side view of an electric vehicle according to an embodiment of the present invention. Fig. 2 is an explanatory diagram showing the inside of a swing arm of the electric vehicle shown in Fig. 1. Fig. 3 is a cross-sectional view of the rear end of the swing arm shown in Fig. 2. Fig. 4 is a cross-sectional view of a drive unit including a motor. Fig. 5 is an enlarged explanatory view showing the vicinity of the motor in Fig. 2.

[0009] As shown in Figure 1, the electric vehicle 10 according to this embodiment is an electric scooter, and travels by rotating and driving the rear wheel 12R with the driving force of a motor 16 built into a swing arm 14 that supports the rear wheel 12R. Note that the electric vehicle 10 is not limited to an electric scooter. For example, it may be any electric straddle-type vehicle that is driven by the motor 16. In the following explanation, a scooter-type electric vehicle 10 will be described.

[0010] The electric vehicle 10 includes a body frame 18, a body cover 20 that covers the body frame 18, a drive unit 22 that includes a motor 16 that drives the rear wheel 12R, and a control device 24 (see FIG. 2) that controls the drive of the drive unit 22. The body frame 18 includes a head pipe 181 at the front end, a down pipe 182 that extends diagonally downward and rearward from the head pipe 181, an underframe portion 183 that extends rearward from the rear end of the down pipe 182, and side frame portions 184 that extend diagonally upward and rearward from the rear end of the underframe portion 183. The head pipe 181 supports front forks 26 that extend diagonally downward and forward. The tips of the front forks 26 support the front wheel 12F.

[0011] The body frame 18 includes a pivot shaft 28. The pivot shaft 28 is provided on a side frame portion 184 and extends in the left-right direction (vehicle width direction) of the electric vehicle. The pivot shaft 28 supports the swing arm 14.

[0012] The swing arm 14 extends in the front-to-rear direction of the electric vehicle 10. The swing arm 14 incorporates the drive unit 22 so that the drive unit 22 is disposed to the side of the rear wheel 12R. As shown in FIG. 2 , one end 14F of the swing arm 14 is an end that is disposed in the front of the electric vehicle 10. The one end 14F of the swing arm 14 (hereinafter also referred to as the front end 14F) is rotatably supported on the body frame 18 via a pivot shaft 28. The other end 14R of the swing arm 14 (hereinafter referred to as the rear end 14R) is an end that is disposed in the rear of the electric vehicle 10. The rear end 14R of the swing arm 14 is disposed to the left of the rear wheel 12R and rotatably supports the rear wheel 12R.

[0013] 1, a rear suspension 30 is provided between the rear end 14R of the swing arm 14 and the side frame portion 184. The upper end of the rear suspension 30 is connected to the side frame portion 184, and the lower end of the rear suspension 30 is connected to the rear end 14R of the swing arm 14.

[0014] 2, the swing arm 14 includes a case 32 and a cover portion 34. The case 32 extends along the front-rear direction of the electric vehicle 10. A front end portion 14F of the case 32 is supported by the pivot shaft 28.

[0015] As shown in FIG. 3 , the case 32 includes a motor housing 36 that opens outward in the vehicle width direction of the body frame 18. The motor housing 36 is provided at the rear end 14R of the case 32 and houses the drive unit 22. The motor housing 36 has a housing space 38 that can house the drive unit 22. The motor housing 36 has an opening 40 that opens to one side in the vehicle width direction and communicates with the housing space 38. That is, the motor housing 36 opens to one side in the vehicle width direction. The one side in the vehicle width direction is the outward side in the vehicle width direction, which is the direction opposite the rear wheel 12R. When the swing arm 14 is viewed from the vehicle width direction, the motor housing 36 has a substantially circular shape (see FIG. 2 ).

[0016] The cover portion 34 is attached to the case 32 and covers the opening 40 of the motor housing portion 36. The attachment direction of the cover portion 34 is the vehicle width direction of the electric vehicle 10. The cover portion 34 is fastened to the side of the case 32 with multiple case fastening members 421. The inner surface 341 of the cover portion 34 includes a facing portion 44, multiple board mounting portions 46, and multiple stator mounting portions 48. The facing portion 44 faces the motor housing portion 36 and the motor 16 of the drive unit 22. The facing portion 44 is a flat surface that intersects with the axial direction of the motor 16 of the drive unit 22. The facing portion 44 has multiple board mounting portions 46. Each board mounting portion 46 protrudes axially from the inner surface 341 of the cover portion 34. A board fastening hole 461 is provided at the center of each board mounting portion 46. Each board fastening hole 461 is formed along the extension direction of the board mounting portion 46.

[0017] The multiple stator mounting portions 48 are disposed radially outward from the opposing portion 44. Each stator mounting portion 48 protrudes in the axial direction from the inner surface 341 of the cover portion 34. The protruding height of the stator mounting portion 48 from the inner surface 341 is greater than the protruding height of the board mounting portion 46 from the inner surface 341. A stator fastening hole 481 is formed in the center of each stator mounting portion 48. Each stator fastening hole 481 is a screw hole formed from the end of the stator mounting portion 48 toward the inner surface 341 of the cover portion 34.

[0018] The outer surface 342 of the cover portion 34 is the surface opposite to the inner surface 341 in the thickness direction of the cover portion 34. The outer surface 342 of the cover portion 34 is exposed to the outside of the electric vehicle 10. The outer surface 342 of the cover portion 34 is provided with a fin structure 50.

[0019] As shown in Fig. 2, the fin structure 50 is for dissipating heat transferred from the drive unit 22 and the control device 24 to the cover portion 34. The fin structure 50 has a plurality of heat dissipation fins 501. As shown in Fig. 3, each heat dissipation fin 501 protrudes in a direction away from the outer surface 342 of the cover portion 34. Each heat dissipation fin 501 is linear and extends in the front-to-rear direction of the electric vehicle 10 on the cover portion 34. The plurality of heat dissipation fins 501 are arranged parallel to and spaced apart from each other in the up-down direction. In other words, the extension direction of the heat dissipation fins 501 is the traveling direction of the electric vehicle 10.

[0020] 4, the drive unit 22 is provided on the swing arm 14 and drives the rear wheel 12R. The drive unit 22 includes a motor 16 and a reducer 54.

[0021] As shown in Fig. 5, the motor 16 includes a rotor 56, a stator 58 surrounding the rotor 56, and an annular bus ring 62. The rotor 56 has a rotor body 561 and a rotating shaft 562. A plurality of magnets (not shown) are provided on the outer periphery of the rotor body 561. The rotating shaft 562 is press-fitted into the center of the rotor body 561 along the axial direction of the rotor body 561. This connects the rotor body 561 and the rotating shaft 562 and causes them to rotate integrally.

[0022] The stator 58 includes a stator core 58A and a plurality of coils 60 wound around the stator core 58A. As shown in FIG. 3, the stator 58 is fixed to the cover portion 34 of the swing arm 14 along the axial direction of the stator 58. As shown in FIG. 5, the stator core 58A includes an annular portion 581 and a wound portion 582. The stator core 58A is formed by stacking a plurality of steel plates (not shown) in the axial direction. The annular portion 581 has a plurality of mounting holes 64 that penetrate the steel plates in the thickness direction. The multiple mounting holes 64 are arranged spaced apart from one another in the circumferential direction of the annular portion 581.

[0023] 3, the stator core 58A further includes a first axial end face 661 provided on one axial side of the stator core 58A, and a second axial end face 662 provided on the other axial side of the stator core 58A. When the drive unit 22 including the stator 58 is housed in the motor accommodating portion 36, the first axial end face 661 faces the cover portion 34 and the control device 24 in the axial direction, and the second axial end face 662 faces the bottom surface of the motor accommodating portion 36. The second axial end face 662 is a surface provided on the opposite side of the stator core 58A from the first axial end face 661 in the axial direction.

[0024] The first axial end face 661 of the annular portion 581 abuts against the stator mounting portion 48 of the cover portion 34. The mounting holes 64 of the stator core 58A face the stator fastening holes 481. The stator fastening members 422 are inserted into the mounting holes 64 from the second axial end face 662 of the stator core 58A, and the stator fastening members 422 are fastened to the stator fastening holes 481. With the first axial end face 661 of the stator core 58A facing the cover portion 34, the stator 58 is fixed to the cover portion 34. A space 68 is defined between the stator core 58A and the cover portion 34 in the axial direction of the stator core 58A.

[0025] As shown in Fig. 5, the coil 60 is wound around the winding portion 582 of the stator core 58A multiple times. As shown in Fig. 3, the ends of the coil 60 wound around each winding portion 582 are connected to the bus ring 62. The coil 60 includes a first coil end 601 and a second coil end 602. The first coil end 601 protrudes in the axial direction of the stator core 58A from the first axial end face 661 toward the cover portion 34. The second coil end 602 protrudes in the axial direction of the stator core 58A from the second axial end face 662 toward the bottom surface of the motor accommodating portion 36.

[0026] As shown in FIG. 2 , when viewed in the axial direction of the stator core 58A, the outer edge portion 50A of the fin structure 50 provided on the cover portion 34 is positioned radially outward from the outer edge portion 59 of the stator core 58A. The outer edge portion 50A of the fin structure 50 is composed of outer edge portions 501A of multiple heat dissipation fins 501, and the outer edge portion 59 of the stator core 58A is the outer periphery of the annular portion 581. That is, the outer edge portion 501A of each of the multiple heat dissipation fins 501 is positioned radially outward from the outer periphery of the annular portion 581 of the stator core 58A. Note that the outer edge portion 50A of the fin structure 50 is not limited to being positioned radially outward from the outer edge portion 59 of the stator core 58A. For example, the outer edge portion 50A of the fin structure 50 may be positioned radially inward from the outer edge portion 59 of the stator core 58A.

[0027] As shown in FIG. 4 , the reducer 54 reduces the speed of the driving force of the motor 16 and transmits it to the rear wheel 12R. The reducer 54 is provided at the rear end 14R of the swing arm 14 and is disposed between the motor 16 and the rear wheel 12R. The reducer 54 includes an intermediate shaft 72 having a first gear 701 and a rear wheel shaft 74 having a second gear 702, and the rear wheel shaft 74 is the axle of the rear wheel 12R. The first gear 701 is meshed with one end of a rotating shaft 562 of the motor 16. The second gear 702 is meshed with the outer periphery of the intermediate shaft 72. When the rotating shaft 562 of the motor 16 rotates, the driving force of the intermediate shaft 72 is reduced in speed by the first gear 701 and transmitted, and is further reduced in speed by the second gear 702 meshed with the intermediate shaft 72 and transmitted to the rear wheel shaft 74. After being reduced in speed by the reducer 54, the driving force of the motor 16 is transmitted to the rear wheel 12R via the rear wheel shaft 74.

[0028] As shown in FIG. 3 , the control device 24 is disposed between the stator 58 of the motor 16 and the cover portion 34 in the drive unit 22. The control device 24 includes a circuit board 76 and a plurality of electrical components 78 mounted on the circuit board 76. The control device 24 is disposed in the motor accommodating portion 36 in a space 68 between the stator core 58A of the motor 16 and the inner surface 341 of the cover portion 34. The circuit board 76 abuts against an end of the circuit board mounting portion 46 of the cover portion 34. The circuit board 76 has a plurality of holes 80, and circuit board fastening members 423 are inserted into the holes 80 of the circuit board 76 from the stator 58 side. The circuit board fastening members 423 are fastened to the circuit board fastening holes 461 of the circuit board mounting portion 46, thereby fixing the control device 24 including the circuit board 76 to the circuit board mounting portion 46. In the space 68, the control device 24 is disposed substantially parallel to the first axial end face 661 of the stator core 58A and the inner surface 341 of the cover portion 34. The control device 24 is spaced apart from each of the first axial end face 661 of the stator core 58A and the inner surface 341 of the cover portion 34.

[0029] The control device 24 faces the bus ring 62 attached to the first axial end surface 661 of the stator core 58A. The bus ring 62 to which the coil 60 is connected and the substrate 76 are electrically connected by a connecting member 82.

[0030] Furthermore, the motor accommodating portion 36 of the swing arm 14 includes a wall portion 321 facing the second coil end 602 of the coil 60, and a surrounding wall portion 322 surrounding the outer periphery of the stator core 58A.

[0031] The wall portion 321 is disposed inward in the vehicle width direction in the motor housing portion 36. The wall portion 321 is provided on the rear wheel 12R side in the vehicle width direction of the case 32 (see FIG. 4). The wall portion 321 is annular and centered on the central axis of the stator 58. The wall portion 321 and the second axial end face 662 of the stator core 58A are spaced apart in the axial direction of the stator 58.

[0032] The wall portion 321 has a recess 86 recessed in a direction away from the stator core 58A in the axial direction of the motor 16. The recess 86 is annular along the wall portion 321. Note that the recess 86 is not limited to being annular. For example, the recess 86 may be provided in only a portion of the annular wall portion 321.

[0033] The surrounding wall portion 322 is disposed radially outward of the annular portion 581 of the stator core 58A. The surrounding wall portion 322 has an annular shape that follows the outer periphery of the stator core 58A. The surrounding wall portion 322 may be provided with a recess that is recessed radially outward.

[0034] The swing arm 14 further includes a plurality of heat dissipation members 84 inside. Each of the plurality of heat dissipation members 84 is, for example, a thermally conductive material formed from a gel-like substance (TIM: Thermal Interface Material). Each of the heat dissipation members 84 is, for example, thermally conductive grease or thermally conductive gel. Note that each of the heat dissipation members 84 is not limited to being formed from a gel-like substance. For example, each of the heat dissipation members 84 may be a thermally conductive material made from a solid substance.

[0035] The multiple heat dissipation members 84 include a board heat dissipation member 84A, a first motor heat dissipation member 841, and a second motor heat dissipation member 842. The board heat dissipation member 84A is disposed between the board 76 of the control device 24 and the inner surface 341 of the cover portion 34. The board heat dissipation member 84A is annular. For example, the board heat dissipation member 84A is disposed so as to surround the periphery of the multiple board mounting portions 46. The board heat dissipation member 84A contacts the inner surface 341 of the cover portion 34 and the edge surface of the board 76. At this time, because the board heat dissipation member 84A is gel-like, the board heat dissipation member 84A conforms to the shape of the board 76 of the control device 24 and adheres tightly to it. Heat generated in the control device 24, including the board 76, is cooled by the board heat dissipation member 84A and conducted to the cover portion 34.

[0036] The first motor heat dissipation member 841 is provided between the wall 321 of the case 32 and the stator 58. The first motor heat dissipation member 841 is provided in an annular shape along the wall 321. The first motor heat dissipation member 841 is provided in the recess 86 of the wall 321 and is in contact with the wall 321 and the second coil end 602. That is, the first motor heat dissipation member 841 faces the second coil end 602 in the axial direction of the motor 16. At this time, because the first motor heat dissipation member 841 is gel-like, the first motor heat dissipation member 841 conforms to the shape of the second coil end 602 and makes close contact. Heat generated in the coil 60 when the motor 16 is running is cooled by the first motor heat dissipation member 841 and conducted to the wall 321 of the case 32.

[0037] The second motor heat dissipation member 842 is provided between the surrounding wall portion 322 of the case 32 and the stator core 58A. The second motor heat dissipation member 842 is provided in an annular shape along the surrounding wall portion 322. The second motor heat dissipation member 842 is provided inside the surrounding wall portion 322. The second motor heat dissipation member 842 contacts the surrounding wall portion 322 and the outer periphery of the annular portion 581 of the stator core 58A. That is, the second motor heat dissipation member 842 faces the outer periphery of the stator core 58A in the radial direction of the motor 16. At this time, because the second motor heat dissipation member 842 is gel-like, the second motor heat dissipation member 842 conforms to the shape of the outer periphery of the stator core 58A and adheres closely to it. When the motor 16 is driven, heat generated in the coil 60 passes through the stator core 58A, is cooled by the second motor heat dissipation member 842 together with heat generated in the stator core 58A, and is conducted to the surrounding wall portion 322 of the case 32.

[0038] Each of the board heat dissipation member 84A, the first motor heat dissipation member 841, and the second motor heat dissipation member 842 may be a sheet-shaped heat dissipation member 84. Furthermore, the heat dissipation member 84 is not limited to including the board heat dissipation member 84A, the first motor heat dissipation member 841, and the second motor heat dissipation member 842. For example, two or less of the heat dissipation members 84 selected from the board heat dissipation member 84A, the first motor heat dissipation member 841, and the second motor heat dissipation member 842 may be included.

[0039] Next, the operation of the drive unit 22 in the electric vehicle 10 will be described. When a driver (not shown) opens a throttle provided on the handle of the electric vehicle 10, current is applied to the bus ring 62 of the motor 16 from a power source (not shown) via the control device 24, and the coil 60 is excited to generate a rotating magnetic field, which drives the rotor 56 to rotate inside the stator 58. The rotational force (driving force) of the rotor 56 is reduced in speed via the reducer 54 and then transmitted to the rear wheel 12R. Driving the rear wheel 12R causes the electric vehicle 10 to travel.

[0040] This embodiment has the following advantages.

[0041] As shown in Figure 1, the electric vehicle 10 includes a swing arm 14 that is pivotally supported on a pivot shaft 28 that is provided on a body frame 18. As shown in Figure 3, the swing arm 14 has a cover portion 34 that covers an opening 40 of a motor housing portion 36 that houses the motor 16. A stator 58 of the motor 16 is fixed to the cover portion 34, and the control device 24 is disposed between the stator 58 and the cover portion 34.

[0042] According to this configuration, compared to a configuration in which the stator 58 is fixed to the case 32 of the swing arm 14, fixing the stator 58 (stator core 58A) of the motor 16 to the cover portion 34 can suppress dimensional variations between the cover portion 34 and the stator 58. Therefore, by reducing the gap between the cover portion 34 and the control device 24, which is disposed between the cover portion 34 and the stator 58, the heat dissipation of the control device 24 can be effectively improved.

[0043] Because the stator 58 of the motor 16 is fixed to the cover portion 34, the control device 24 and the stator 58 can be removed together with the cover portion 34 while the coil 60 of the stator 58 and the control device 24 (substrate 76) are connected by the bus ring 62. This makes it easier to attach and detach the control device 24 and the stator 58 to and from the swing arm 14 compared to a configuration in which the control device 24 is fixed to the cover portion 34 side and the bus ring 62 is fixed to the stator 58 side. Because no connecting member is required to connect the control device 24 and the bus ring 62, there is no need to provide an access hole in the cover portion 34 to connect the connecting member from outside the swing arm 14, which is advantageous.

[0044] The board heat dissipation member 84A is disposed between the control device 24 and the cover portion 34. Providing the board heat dissipation member 84A can thereby further improve the heat dissipation performance of the control device 24. By keeping the gap between the control device 24 and the cover portion 34 substantially constant, heat dissipation members 84 of various shapes, including sheet-like shapes, can be effectively disposed in the gap.

[0045] 2, the cover portion 34 is provided with a fin structure 50 having a plurality of heat dissipation fins 501 disposed on the outer surface 342 of the swing arm 14. An outer edge portion 50A of the fin structure 50 is located radially outward of the stator core 58A relative to an outer edge portion 59 of the stator core 58A. By providing the fin structure 50 on the cover portion 34 so that it is located radially outward of the outer edge portion 59 of the stator core 58A, heat dissipation from the motor 16 from the cover portion 34 side can be promoted.

[0046] 3, stator core 58A has a second axial end face 662 provided on the opposite side to first axial end face 661, and coil 60 of motor 16 has second coil ends 602 that protrude in the axial direction from second axial end face 662 of stator 58. Motor accommodating section 36 of case 32 has wall portion 321 that faces second coil end 602 in the axial direction, and first motor heat dissipation member 841 is disposed between wall portion 321 and stator 58. This allows first motor heat dissipation member 841 to improve the heat dissipation of coil 60, and enables motor 16 including coil 60 to be cooled effectively.

[0047] The wall portion 321 has a recess 86 recessed in a direction away from the motor 16, and the first motor heat dissipation member 841 is disposed in the recess 86. This allows the first motor heat dissipation member 841 to be disposed so as to effectively face the second coil end 602 by the recess 86.

[0048] The case 32 is provided in the motor housing portion 36 and includes a surrounding wall portion 322 that surrounds the outer periphery of the stator core 58A, and a second motor heat dissipation member 842 is disposed between the surrounding wall portion 322 and the stator core 58A. This allows the second motor heat dissipation member 842 to improve the heat dissipation performance of the stator core 58A.

[0049] The heat dissipation member 84 is made of a gel-like substance, which allows the heat dissipation member 84 to remain effectively in the gap between the control device 24 and the cover portion 34 and between the stator core 58A and the case 32.

[0050] In addition to the above disclosure, the following additional notes are disclosed.

[0051] (Supplementary Note 1) An electric vehicle (10) comprises a body frame (18), a pivot shaft (28) provided on the body frame, a swing arm (14) having one end (14F) journaled on the pivot shaft and the other end (14R) supporting a rear wheel (12R), a motor (16) disposed on the swing arm and driving the rear wheel, and a control device (24) for controlling the drive of the motor, the swing arm having a motor housing section (36) opening outward in the vehicle width direction of the body frame, a case (32) in which the motor is housed in the motor housing section, and a cover section (34) covering an opening (40) of the motor housing section, a stator (58) of the motor fixed to the cover section, and the control device disposed between the stator and the cover section.

[0052] With this configuration, compared to a configuration in which the stator is fixed to the swing arm case, fixing the motor stator to the cover can reduce dimensional variations between the cover and the stator, thereby reducing the gap between the cover and the control device disposed between the cover and the stator, thereby effectively improving the heat dissipation of the control device.

[0053] (Supplementary Note 2) In the electric vehicle described in Supplementary Note 1, a heat dissipation member (84, 84A) may be disposed between the control device and the cover. According to this configuration, the heat dissipation performance of the control device can be further improved by providing the heat dissipation member. By making the gap between the control device and the cover substantially constant, the sheet-shaped heat dissipation member can be effectively disposed in the gap.

[0054] (Supplementary Note 3) In the electric vehicle described in Supplementary Note 1 or 2, the cover portion may include a fin structure (50) arranged on an outer surface (342) of the swing arm and having a plurality of fins (501), and an outer edge portion (50A) of the fin structure may be located radially outward of the stator than an outer edge portion (59) of the stator. According to this configuration, by providing the fin structure on the cover portion so as to be located radially outward of the outer edge portion of the stator, heat dissipation of the motor from the cover portion side can be promoted.

[0055] (Supplementary Note 4) In the electric vehicle described in any one of Supplementary Notes 1 to 3, the stator may have a first axial end face (661) facing the control device in the axial direction of the stator and a second axial end face (662) provided on the opposite side of the first axial end face in the axial direction, the motor may have a coil (60) wound around a stator core (58A) of the stator, the coil having a coil end (602) protruding in the axial direction from the second axial end face of the stator core, the motor accommodating portion of the case may have a wall portion (321) facing the coil end in the axial direction, and a heat dissipation member (84, 841) may be disposed between the wall portion and the stator. With this configuration, the heat dissipation member can improve the heat dissipation of the coil, and the motor including the coil can be effectively cooled.

[0056] (Supplementary Note 5) In the electric vehicle described in Supplementary Note 4, the wall portion may have a recess (86) recessed in a direction away from the motor, and the heat dissipation member may be disposed in the recess. With this configuration, the recess allows the heat dissipation member to be disposed so as to effectively face the coil end.

[0057] (Supplementary Note 6) In the electric vehicle described in any one of Supplementary Notes 1 to 5, the case may include a surrounding wall portion (322) provided in the motor housing portion and surrounding an outer periphery of the stator, and a heat dissipation member (84, 842) may be disposed between the surrounding wall portion and the stator. With this configuration, the heat dissipation member can improve the heat dissipation of the stator.

[0058] (Supplementary Note 7) In the electric vehicle described in any one of Supplementary Notes 2, 4, and 6, the heat dissipation member may be made of a gel-like substance. With this configuration, the heat dissipation member can be effectively retained in the gap between the control device and the cover, and between the stator and the case.

[0059] The present invention is not limited to the above disclosure, and various configurations can be adopted without departing from the gist of the present invention.

[0060] REFERENCE SIGNS LIST 10... Electric vehicle 12R... Rear wheel 14... Swing arm 14F... One end 14R... Other end 16... Motor 18... Body frame 24... Control device 28... Pivot shaft 32... Case 34... Cover portion 36... Motor housing portion 40... Opening

Claims

1. Body frame (18) and A pivot shaft (28) provided on the vehicle body frame (18), A swing arm (14) has one end (14F) pivotally supported on the pivot shaft (28) and the other end (14R) supporting the rear wheel (12R), A motor (16) is positioned on the swing arm (14) and drives the rear wheel (12R), A control device (24) that controls the drive of the motor (16), In an electric vehicle (10) equipped with, The aforementioned swing arm (14) is The vehicle body frame (18) has a motor housing section (36) that opens outward in the vehicle width direction, and the motor (16) is housed in the motor housing section (36) in a case (32), A cover portion (34) that covers the opening (40) of the motor housing portion (36), Equipped with, The stator (58) of the motor (16) is fixed to the cover portion (34), The electric vehicle (10) is configured such that the control device (24) is positioned between the stator (58) and the cover portion (34).

2. In the electric vehicle (10) described in claim 1, An electric vehicle (10) in which heat dissipation members (84, 84A) are arranged between the control device (24) and the cover portion (34).

3. In the electric vehicle (10) according to claim 1 or 2, The cover portion (34) is provided with a fin structure (50) having a plurality of fins (501) arranged on the outer surface (342) of the swing arm (14), The outer edge (50A) of the fin structure (50) is located radially outward of the stator (58) than the outer edge (59) of the stator (58) in the electric vehicle (10).

4. In the electric vehicle (10) described in claim 1, The stator (58) has a first axial end face (661) facing the control device (24) in the axial direction of the stator (58), A second axial end face (662) is provided on the opposite side of the first axial end face (661) in the axial direction, It has, The motor (16) has a coil (60) wound around the stator core (58A) of the stator (58), The coil (60) has a coil end (602) that protrudes in the axial direction from the second axial end face (662) of the stator core (58A), The motor housing portion (36) of the case (32) has a wall portion (321) facing the coil end (602) in the axial direction. A heat dissipation member (84, 841) is arranged between the wall portion (321) and the stator (58) in the electric vehicle (10).

5. In the electric vehicle (10) according to claim 4, The wall portion (321) has a recess (86) that is recessed in a direction away from the motor (16), An electric vehicle (10) in which the heat dissipation members (84, 841) are arranged in the recess (86).

6. In the electric vehicle (10) described in claim 1, The case (32) is provided in the motor housing (36) and includes a surrounding wall portion (322) that surrounds the outer periphery of the stator (58). An electric vehicle (10) in which heat dissipation members (84, 842) are arranged between the surrounding wall portion (322) and the stator (58).

7. In the electric vehicle (10) according to any one of claims 2, 4, or 6, The heat dissipation members (84, 84A, 841, 842) are made of a gel-like substance, in an electric vehicle (10).

8. In the electric vehicle (10) described in claim 1, The control device (24) is attached to the cover portion (34) and is an electric vehicle (10).