CN112770968B - Electric vehicle - Google Patents

Abstract

The electric vehicle (10) has a motor housing section (98c), and the motor housing section (98c) is provided to the swing arm (18) and houses the motor (20). In this case, the motor (20) has a stator (90), a rotor (92), and a motor housing (94), and the motor housing (94) houses the stator (90) in a fixed state and houses the rotor (92) in a freely rotatable manner. In addition, the portion of the motor housing (94) that faces the motor housing (98c) is fixed to the motor housing (98 c).

Description

Electric vehicle

Technical Field

The present invention relates to an electric vehicle (electric vehicle) in which a motor is disposed in a swing arm (swing arm) rotatably supported by a pivot shaft (axle-supported to the pivot axis).

Background

Japanese patent laid-open publication No. 2012-171548 discloses an electric vehicle having: a vehicle body frame; a pivot shaft provided on the vehicle body frame; a swing arm having one end rotatably supported by the pivot shaft; a rear wheel supported by the other end of the swing arm; and a motor, which is disposed inside the swing arm, for driving the rear wheel. In this case, the swing arm has a swing arm main body that rotatably supports the rear wheel and a swing arm cover (swing arm cover); the swing arm cover covers the swing arm main body from the outside in the vehicle width direction. The motor is housed in an inner space between the swing arm main body and the swing arm cover.

Disclosure of Invention

When the motor is housed in the swing arm, the stator and the rotor are assembled at a position near the transmission of the swing arm main body, then the motor cover is covered so as to cover the stator and the rotor from the outside in the vehicle width direction, and finally the swing arm main body is covered by the swing arm cover. In this way, since the stator and the rotor, which are components of the motor, are directly assembled to the swing arm, there is room for improvement from the viewpoint of improving the productivity of the electric vehicle.

Accordingly, an object of the present invention is to provide an electric vehicle capable of improving production efficiency.

The technical scheme of the invention is an electric vehicle, which is provided with a vehicle body frame, a pivot shaft, a swing arm and a motor, wherein the pivot shaft is arranged on the vehicle body frame; the electric vehicle further includes a motor housing portion provided in the swing arm for housing the motor, the motor housing portion having a stator fixedly housed therein and a rotor rotatably housed therein, and an opposing portion of the motor housing opposing the motor housing portion being fixed to the motor housing portion.

According to the present invention, since only the motor housing in which the stator and the rotor are housed is fixed to the motor housing portion, the motor is disposed in the swing arm, and therefore, the production efficiency of the electric vehicle can be improved.

Drawings

Fig. 1 is a left side view of the electric vehicle according to the present embodiment.

Fig. 2 is a perspective view of the electric vehicle of fig. 1 viewed from the left rear side around the rear wheel.

Fig. 3 is a left side view of the swing arm cover of fig. 1 and 2 in a state of being detached.

Fig. 4 is a left side view of the left rotor support portion of fig. 3 in a state where it is removed.

Fig. 5 is a sectional view taken along V-V of fig. 3.

Fig. 6 is a right side view showing the swing arm and the like broken.

Fig. 7 is a bottom view of the front end periphery of the swing arm.

Fig. 8 is a left side view illustrating the reducer housing portion.

Fig. 9 is a perspective view of a swing arm including a speed reducer housing portion, a brake mechanism, and a breather pipe (break pipe).

Fig. 10 is a cross-sectional view of modification 1 taken along line X-X in fig. 3.

Fig. 11A is a side view showing a gasket of a comparative example, and fig. 11B is a side view showing a gasket of modification 2.

Fig. 12A and 12B are side views showing a gasket according to modification 2.

Fig. 13 is a perspective view showing a motor-side gear of modification 3.

Fig. 14A and 14B are sectional views showing the periphery of the motor-side gear of modification 3.

Fig. 15 is a sectional view showing the periphery of the motor-side gear of modification 3.

Detailed Description

A preferred embodiment of an electric vehicle according to the present invention will be described below with reference to the drawings.

[1. schematic configuration of electric vehicle 10 according to the present embodiment ]

Fig. 1 is a left side view of an electric vehicle 10 according to the present embodiment. In the following description, the front-rear, left-right, and up-down directions are described in terms of directions viewed by an occupant seated on the seat 12 of the electric vehicle 10. In the electric vehicle 10, components arranged in a pair on the left and right sides may be described by a letter "L" for the left component and a letter "R" for the right component.

The electric vehicle 10 is an electric motorcycle having a low step portion 14, and travels by rotating a rear wheel 16 by a driving force of a motor 20, wherein the motor 20 is built in a swing arm 18, and the swing arm 18 rotatably supports the rear wheel 16. The electric vehicle 10 according to the present embodiment is not limited to the electric motorcycle (electric motorcycle) shown in fig. 1, and can be applied to various electric straddle-type vehicles driven by the motor 20. In the following description, the scooter-type electric vehicle 10 will be described.

The electric vehicle 10 includes a vehicle body frame 22 and a vehicle body cover 24 made of synthetic resin covering the vehicle body frame 22. The vehicle body frame 22 includes: a head pipe (head pipe)26 at the front end; a down pipe (down pipe)28 extending obliquely rearward and downward from the head pipe 26; a pair of left and right chassis portions (under frame sections) 30L, 30R extending rearward from the rear end of the lower tube 28; side frame sections (side frame sections) 32L and 32R extend obliquely rearward and upward from rear ends of the chassis sections 30L and 30R. The side frame portions 32L, 32R include: upright portions 34L, 34R extending obliquely rearward and upward from the pair of left and right undercarriage portions 30L, 30R; rear frames (rear frames) 36L and 36R extend rearward from the pair of left and right rising portions 34L and 34R. The rear ends of the pair of left and right rear frames 36L, 36R are connected together by a tail pipe section 38.

Front forks (front fork)40L and 40R are mounted to the head pipe 26 so as to be steerable. A handle 44 is attached to an upper portion of the front forks 40L and 40R via a steering column 42. Front wheels 46 are attached to lower ends of the front forks 40L and 40R. A front fender 48 that covers the front wheel 46 from above is attached to the front forks 40L, 40R.

A connection support portion 50 including a pivot bracket 50a is provided between the undercarriage portions 30L, 30R and the side frame portions 32L, 32R. The connection support portion 50 supports a pivot shaft 54 extending in the left-right direction (vehicle width direction) of the electric vehicle 10. The swing arm 18 has a front end (one end) rotatably supported by the pivot shaft 54. The swing arm 18 extends from the pivot shaft 54 toward the left side of the rear wheel 16 in the front-rear direction of the electric vehicle 10. The rear end (the other end) of the swing arm 18 supports the rear wheel 16.

The swing arm 18 incorporates a motor 20 such that the motor 20 is disposed on the left side of the rear wheel 16. Therefore, the swing arm 18 is configured as a swing type power unit. A rear shock absorber (rear shock) 56 is connected between the rear end portion of the swing arm 18 and the left rear frame 36L. A rear fender 58 is attached to the rear frames 36L and 36R so as to cover the rear wheel 16 from above. Further, another fender 60 is attached to the swing arm 18, and the fender 60 is capable of swinging together with the swing arm 18 while directly covering the rear wheel 16 from above between the rear fender 58 and the rear wheel 16.

The rear frames 36L, 36R support the seat 12 on which the occupant sits from below. Between the seat 12 and the pivot shaft 54, a battery 62 of the electric vehicle 10 is disposed in a space between the pair of right and left rising portions 34L, 34R. The battery 62 is supported by the pair of right and left rising portions 34L, 34R, the rear frames 36L, 36R, and the pipe 64, wherein the pipe 64 connects the rising portions 34L, 34R at the front.

A PCU (power control unit)66 as an electronic component supported by the left and right standing portions 34L, 34R is supported at a position diagonally behind and below the battery 62 in front of the rear wheel 16. The PCU66 is configured to include an inverter and the like, and converts dc power supplied from the battery 62 into ac power, for example, and supplies the converted ac power to the motor 20. The PCU66 also converts ac power generated by the motor 20 during regeneration of the motor 20 into dc power to charge the battery 62. The positions of the battery 62 and the PCU66 shown in fig. 1 are examples, and may be arranged at other positions in the electric vehicle 10. For example, the battery 62 may be disposed in a space between the pair of right and left chassis portions 30L, 30R.

The body cover 24 is a cover that covers the body frame 22 and the like, and includes a front cover 68, a handlebar cover 70, leg shields (leg shields) 72, pedal-side covers 74L, 74R, a seat lower cover 76, rear side covers (rear side covers) 78L, 78R, and the like. The front cover 68 covers the front end portion of the body frame 22 such as the head pipe 26 from the front. The handlebar cover 70 is located above the front cover 68 and covers the right and left center portions of the handlebar 44. The leg shield 72 is attached to the front cover 68 and covers the head pipe 26 and the down pipe 28 from behind. The seat lower cover 76 covers a space under the seat 12 from the front.

A pair of left and right step side covers 74L, 74R are connected to the leg shield 72 and the seat lower cover 76, and cover the pair of left and right undercarriage portions 30L, 30R from both left and right sides. The rear side covers 78L and 78R are connected to the rear edge portion of the seat lower cover 76, and cover the PCU66 and the like from both the left and right sides.

A main stand (main stand)80 is disposed on a side of the swing arm 18. In this case, a shaft 82 of the main stand 80 is provided below the swing arm 18, and the main stand 80 is disposed such that a part of the main stand 80 is housed in a recess 84, the recess 84 being formed by recessing the left side portion of the swing arm 18. In addition, a sub-bracket 86 is disposed near the left standing portion 34L.

[2. characteristic Structure of the present embodiment ]

Next, a characteristic configuration (1 st to 4 th configurations) of the electric vehicle 10 according to the present embodiment will be described with reference to fig. 1 to 15.

< 2.1 Structure 1 >

The structure 1 is as follows: the motor 20 is configured as an assembly (unit) in which a stator 90 and a rotor 92, which are driving parts of the motor 20, are assembled inside a motor housing 94, and the motor 20 is housed inside the swing arm 18 to configure a swing-type power unit. That is, the mounting work of the motor 20 with respect to the swing arm 18 can be completed only by housing the finished motor 20 in the swing arm 18, wherein the finished motor 20 houses the stator 90 and the rotor 92, and the motor shaft 96 is exposed from the motor housing 94. Here, the structure of the swing arm 18 accommodating the motor 20 will be described in more detail.

Swing arm 18 has a swing arm body 98. The swing arm main body 98 is a hollow member having: one end portion 98a extending in the vehicle width direction in a space near the pivot shaft 54 in front of the rear wheel 16; a connecting portion 98b extending rearward from the left side of the one end portion 98 a; a motor housing portion 98c provided in connection with the connecting portion 98b and disposed on the left side of the rear wheel 16; and the other end portion 98d provided rearward of the motor housing portion 98 c.

One end 98a of the swing arm main body 98 constitutes a front end of the swing arm 18 and is rotatably supported by the pivot shaft 54. As described above, the pivot shaft 54 is supported by the vehicle body frame 22 via the connecting support portion 50. As shown in fig. 1, 2, 6, and 7, the connection support portion 50 includes: a pipe 50b extending in the vehicle width direction and connecting the pair of left and right standing portions 34L, 34R; and 4 pivot holders 50a extending rearward from the pipe member 50b and supporting the pivot shafts 54. The 2 projections 98e extend forward from the left and right sides of the one end 98a of the swing arm main body 98 toward the pivot shaft 54. The 2 projecting portions 98e are rotatably supported by the pivot shaft 54 via 2 bearings 100 provided at both ends of the pivot shaft 54 in the vehicle width direction.

In the side views of fig. 1, 3, and 4, the connecting portion 98b of the swing arm main body 98 gradually expands from the front toward the rear. The motor housing portion 98c and the other end portion 98d of the swing arm main body 98 constitute a rear end portion of the swing arm 18. The motor housing portion 98c is formed in a substantially circular shape in the side views of fig. 1, 3, and 4, and the motor housing portion 98c is formed recessed inward in the vehicle width direction in the cross-sectional view of fig. 5. The rear damper 56 is connected to the other end 98d of the swing arm main body 98.

In the swing arm main body 98, a rear portion of the connecting portion 98b and the motor housing portion 98c are opened leftward. The opening is sized to receive the motor 20, and is covered by the swing arm cover 102 from the left side. A swing arm cover 102 is mounted to the swing arm body 98 by a plurality of bolts 104. Fig. 3 to 5 illustrate a state in which the swing arm cover 102 is detached from the swing arm main body 98.

The motor 20 housed in the motor housing 98c is, for example, a three-phase ac motor, and includes a stator 90, a rotor 92, and a motor housing 94, and the motor housing 94 houses the stator 90 and the rotor 92 therein. The motor housing 94 has: a stator support portion 94a which is an outer case of the motor housing 94 and is a cylindrical housing extending in the vehicle width direction; and left and right rotor support portions 94L, 94R as rotor covers for closing the 2 openings at both ends of the stator support portion 94a in the vehicle width direction.

The stator 90 has a cylindrical stator core 90a formed of laminated steel plates. The stator core 90a has a plurality of slots 90b formed at predetermined angular intervals in the circumferential direction of the motor 20. A coil 90c is wound around the plurality of grooves 90 b. The stator support portion 94a is a stator holder that fixedly supports the outer peripheral surface of the stator core 90a, i.e., the outer surface of the stator 90 in the radial direction of the motor 20. Accordingly, the mechanical strength of the stator core 90a formed of laminated steel sheets is enhanced. The stator core 90a is fixed to the stator support 94a by shrink fitting, for example.

A rotor 92 is disposed radially inward of the stator 90. The rotor 92 has a cylindrical rotor core 92a formed of laminated steel plates. The rotor core 92a has a plurality of slots 92b formed at predetermined angular intervals in the circumferential direction of the motor 20. Magnets 92c are disposed in the plurality of grooves 92 b. The motor shaft 96 penetrates the center of the rotor core 92a in the vehicle width direction. Motor shaft 96 extends in the vehicle width direction through an opening formed in the center of each of 2 rotor support portions 94L and 94R. Motor shaft 96 is rotatably supported by 2 rotor support portions 94L and 94R via bearings 106L and 106R provided in 2 openings. That is, the rotor 92 is rotatably supported (rotatably supported) by the 2 rotor support portions 94L, 94R via the motor shaft 96 and the 2 bearings 106L, 106R.

A left end portion 96L of motor shaft 96 projects outward (leftward) in the vehicle width direction from left rotor support portion 94L. In the left rotor support portion 94L, a portion of the motor shaft 96 from which the left end portion 96L protrudes is formed as a recess 108 recessed inward in the vehicle width direction. The recess 108 is covered from the left by a cover member 110. Therefore, even if the swing arm cover 102 is detached from the swing arm main body 98, the left end portion 96L of the motor shaft 96 is not exposed (see fig. 3 and 5).

A rotation angle detecting portion 112 is disposed in an internal space formed by the recess 108 and the cover member 110, and the rotation angle detecting portion 112 detects the rotation angle of the rotor 92 and the motor shaft 96. The rotation angle detection unit 112 is a resolver (resolver), and includes: a resolver rotor 112a attached to the left end portion 96L of the motor shaft 96; and a resolver stator 112b fixed to the left rotor support portion 94L so as to face the resolver rotor 112 a. Since the resolver is well known, a detailed description thereof will be omitted.

On the other hand, a right end portion (distal end portion) 96R of the motor shaft 96 projects inward in the vehicle width direction (right direction) from the right rotor support portion 94R toward the motor housing portion 98c of the swing arm main body 98. Therefore, the right portions of the right rotor support portion 94R and the stator support portion 94a are opposed portions opposed to the motor housing portion 98 c. A speed reducer housing 116 for housing a speed reducer 114 to be described later is provided on the right side of the motor housing 98c of the swing arm main body 98.

The right end portion 96R of the motor shaft 96 is inserted into the reduction gear housing 116, and is axially supported (rotatably supported) by a bearing 118 provided in the reduction gear housing 116. Further, spline machining is performed on the right end portion 96R side of the motor shaft 96. A motor-side gear 120 (gear) for rotating an axle (output shaft) 16a of the rear wheel 16 is inserted into the splined portion. A spacer 122 for preventing the motor-side gear 120 from coming off is provided between the motor-side gear 120 and the bearing 118. In order to replace the motor 20 with the motor housing portion 98c, the spacer 122 is preferably pressed into the motor shaft 96 at a low pressure. The gasket 122 is pressed in by low pressure, so that the assembly is easy.

The reduction gear housing 116 is filled with a lubricating oil for lubricating the motor-side gear 120 and the like constituting the reduction gear 114. Therefore, an oil seal 121 is provided between the right rotor support portion 94R and the motor shaft 96, and this oil seal 121 prevents leakage of the lubricating oil from the speed reducer housing 116 to the motor housing 94. Further, between the right rotor support portion 94R and the motor housing portion 98c, an O-ring 123 for preventing leakage of the lubricating oil from the reduction gear housing portion 116 is provided on the rotor support portion 94R side.

A plurality of screw holes (1 st through hole, 2 nd through hole) 124 extending in the vehicle width direction are formed in the 2 rotor support portions 94L, 94R and the stator support portion 94a at predetermined angular intervals in the circumferential direction of the motor 20. A plurality of bolts 126, 128 are screwed into the threaded holes 124. As shown in fig. 3 to 5, in the present embodiment, screw holes 124 are formed at 9 locations.

Among them, bolts 126 having a short length are screwed into the screw holes 124 at 3 positions. Shorter bolts 126 are used to fix the rotor support portions 94L, 94R and the stator support portion 94 a. As shown in fig. 5, a short bolt 126 is inserted into the screw hole 124 from the left side, whereby the rotor support portion 94L and the stator support portion 94a are fastened to the rotor support portion 94R.

On the other hand, long bolts (fixing means) 128 are screwed into the screw holes 124 in the other 6 locations. Long bolt 128 is used to fix motor housing 94 including 2 rotor support portions 94L and 94R and stator support portion 94a to motor housing portion 98 c. That is, long bolts 128 are inserted into the screw holes 124 from the left side and screwed into bolt holes 130 provided in the motor housing portion 98c, whereby the rotor support portion 94L, the stator support portion 94a, and the rotor support portion 94R are fastened to the motor housing portion 98 c.

The number and formation position of the screw holes 124, and the type and number of the bolts 126 and 128 screwed into the screw holes 124 are arbitrary, and it is needless to say that the design may be changed in accordance with the specifications of the swing arm 18 and the motor 20.

In the structure 1, the motor 20 is mounted on the motor housing portion 98c of the swing arm main body 98 when the electric vehicle 10 is manufactured. The motor 20 is used in the manufacturing process of the electric vehicle 10 in an assembled state (unit) in which the stator 90 and the rotor 92 are housed in the motor housing 94 and the right end portion 96R of the motor shaft 96 is projected from the right rotor support portion 94R. At this time, the short bolts 126 fix the rotor support portions 94L, 94R and the stator support portion 94a in a fully fixed state, while the long bolts 128 may be temporarily fixed.

In this case, first, right end portion 96R of motor shaft 96 is inserted into reducer housing 116 and rotatably supported by bearing 118. At this time, the bearing 118 can rotatably support the right end portion 96R of the motor 20 in a state where the motor-side gear 120 and the spacer 122 are fitted into the spline-processed portion on the right end portion 96R side of the motor shaft 96. Next, the 6 screw holes 124 to which the long bolts 128 are temporarily fixed and the 6 bolt holes 130 on the motor housing portion 98c side are positioned, and then the long bolts 128 are screwed into the screw holes 124 and the bolt holes 130, whereby the motor housing 94 is fixed to the motor housing portion 98 c. Accordingly, the motor 20 is housed in the motor housing portion 98c, and the operation of attaching the motor 20 to the swing arm 18 is completed.

< 2.2 Structure 2 >

The 2 nd structure is a structure for exposing a part of the motor 20 housed in the motor housing portion 98c to the outside, thereby efficiently cooling the motor 20.

As shown in fig. 1 and 2, a swing arm cover 102 is provided with an exposed portion 132, and the exposed portion 132 is an opening portion through which a part of the motor housing 94 is exposed to the outside. Specifically, in the side view of fig. 1, the exposed portion 132 is formed as an arc-shaped opening from the front to the rear at a portion corresponding to the motor housing portion 98c of the swing arm cover 102 so that the rear portion of the motor housing 94 is exposed to the outside. As shown in fig. 2, exposed portion 132 is open to have a constant width in the vehicle width direction, and motor housing 94 is exposed to the outside in the vehicle width direction. The arc-shaped exposed portion 132 is formed to be wider in the vertical direction from the front to the rear, and the exposed area is gradually increased.

Therefore, in the side view of fig. 1, the swing arm cover 102 has a circular portion 102a, and the circular portion 102a covers the central portion of the motor housing 94, that is, the motor shaft 96 and the rotation angle detection portion 112 (see fig. 5), from the left side. As shown in fig. 1 and 2, the circular portion 102a and the rear end portion 102b of the swing arm cover 102 are connected together by a connecting portion 102c extending in the front-rear direction. As shown in fig. 4, the exposed portion 132 is provided so as to correspond to the groove 90b of the wound coil 90 c. As shown in fig. 1, 2, and 4, exposed portion 132 exposes a portion of motor housing 94 to the outside so that a plurality of bolts 126 and 128 are covered by swing arm cover 102.

As mentioned above, the motor 20 is a three-phase ac motor. As will be described later, the motor 20 is driven to rotate by supplying ac power from the PCU66 to the coil 90c via the power supply line 134 as a three-phase electric wire. In this case, the power supply line 134 is drawn forward from the motor 20. Therefore, the swing arm cover 102 and the swing arm main body 98 cover the power supply line 134 from the front and the side.

< 2.3 Structure 3 >

The 3 rd configuration relates to the wiring of the power supply line 134 from the motor 20 and the wiring of the communication line 136 from the rotation angle detecting unit 112.

As shown in fig. 6 and 7, a through hole 138 that opens forward is formed in a portion of one end portion 98a of the swing arm main body 98 that is located forward of the rear wheel 16. The through hole 138 is formed at a position between the 2 bearings 100 above the pivot shaft 54 at the one end portion 98a of the swing arm main body 98.

As shown in fig. 3, 4, 6, and 7, the power supply line 134 is a high-rigidity three-phase wire harness, and is routed inside the swing arm 18 along the internal shape of the swing arm 18. That is, the power supply line 134 extends forward from the motor 20 inside the swing arm 18, is bent inward in the vehicle width direction at the one end 98a of the swing arm main body 98, and extends forward of the swing arm 18 from the through hole 138. In this case, the power supply line 134 extends from between the 2 bearings 100 above the pivot shaft 54 to the front of the swing arm 18 via the through hole 138. Then, the power supply line 134 drawn out from the through hole 138 is routed upward of the pivot shaft 54 and connected to the PCU66 disposed diagonally rearward and downward of the battery 62. Therefore, the PCU66 and the motor 20 supply/receive ac power via the power supply line 134.

On the other hand, a communication line 136 is drawn from the rotation angle detecting unit 112. The communication line 136 is a wire harness having lower rigidity than the power supply line 134. Therefore, the communication line 136 is easier to route than the power supply line 134, and the communication line 136 extends forward from the rotation angle detecting unit 112 in the swing arm 18 so as to extend along the power supply line 134, bends inward in the vehicle width direction at the one end 98a of the swing arm main body 98, and extends forward of the swing arm 18 from the through hole 138. Therefore, the communication line 136 also extends from between the 2 bearings 100 to the front of the swing arm 18 via the through hole 138 above the pivot shaft 54. Then, communication line 136 drawn out from through hole 138 is routed upward of pivot shaft 54 and connected to PCU 66. Therefore, PCU66 and rotation angle detection unit 112 can transmit and receive the detection result of the rotation angle of rotor 92 and motor shaft 96 via communication line 136.

Further, inside the swing arm 18, specifically, in the connection portion 98b of the swing arm main body 98, the power supply line 134 and the communication line 136 are bound by a binding member 140 such as a grommet, and fixed in the connection portion 98b by a holder 142 (see fig. 6 and 7).

Further, since the through hole 138 is formed so as to open forward, there is a possibility that liquid such as water may enter the swing arm 18 through the through hole 138 from the front when the electric vehicle 10 travels. Therefore, a hole 144 for draining water is formed in the bottom of the swing arm main body 98. Fig. 6 and 7 illustrate, as an example, a case where a hole 144 is formed in a portion near the through hole 138 on the bottom of the swing arm main body 98.

Further, a plurality of ribs 146 for reinforcing the strength of the swing arm main body 98 are formed inside the swing arm main body 98 between the through hole 138 and the motor housing portion 98c, specifically, at a portion from the rear portion of the connecting portion 98b to the motor housing portion 98 c.

< 2.4 th Structure 4 >

The 4 th structure is related to the breather pipe 148, and the breather pipe 148 is used to discharge gas containing mist-like lubricating oil to the outside to reduce the internal pressure when the pressure (internal pressure) in the reduction gear housing 116 rises due to a temperature rise in the reduction gear housing 116 and the lubricating oil used in the reduction gear 114 volatilizes. Here, the structure around the reduction gear housing portion 116 will be described.

As shown in fig. 5, 8, and 9, the swing arm 18 is further provided with a speed reducer housing 116, and the speed reducer housing 116 is attached to the vehicle width direction inner side of the swing arm main body 98 and houses the speed reducer 114. A brake mechanism 150 is provided on the vehicle width direction inner side of the speed reducer housing 116 and on the inner side of the wheel portion 16b of the rear wheel 16. Therefore, the motor 20, the reduction gear 114, and the brake mechanism 150 are disposed in this order from the left side to the right side in the vehicle width direction around the rear wheel 16.

Further, a transmission cover 154 is fixed to the right side of the motor housing portion 98c of the swing arm main body 98 by a bolt 152. An inner space formed by the motor housing portion 98c and the transmission cover 154 constitutes a reduction gear housing portion 116.

The speed reducer 114 includes: a motor-side gear 120 mounted on the motor shaft 96; an intermediate shaft 156 disposed rearward of motor shaft 96 and extending in the vehicle width direction; an intermediate gear 158 as a reduction gear attached to the intermediate shaft 156 and meshing with the motor-side gear 120; and an output gear 162 that is attached to the axle 16a of the rear wheel 16 disposed rearward of the intermediate shaft 156 and meshes with a gear portion 160 formed on the left side in the vehicle width direction of the intermediate shaft 156.

The right end portion of the intermediate shaft 156 is rotatably supported by a bearing 164R, and the bearing 164R is disposed on the transmission cover 154. The left end portion of the intermediate shaft 156 is rotatably supported by a bearing 164L, and the bearing 164L is disposed on the right side of the motor housing portion 98 c. The left end portion of the axle 16a is rotatably supported by a bearing 166L, and the bearing 166L is disposed on the right side of the motor accommodating portion 98 c. The right end of the axle 16a is exposed to the outside through the transmission cover 154 and is connected to the wheel portion 16b of the rear wheel 16. The right end side of the axle 16a is rotatably supported by a bearing 166R, and the bearing 166R is disposed on the transmission cover 154.

Therefore, when motor 20 is driven and motor shaft 96 rotates, the driving force of motor 20 is transmitted to axle 16a via motor-side gear 120, intermediate gear 158, intermediate shaft 156, gear portion 160, and output gear 162, thereby enabling rotation of rear wheel 16 connected to axle 16 a. In this case, the speed reducer 114 reduces the rotation speed of the motor shaft 96 via the intermediate gear 158, and rotates the drive axle 16a and the rear wheel 16.

The brake mechanism 150 is a drum brake, and includes: a brake drum 150a provided inside the wheel portion 16 b; 2 brake shoes 150b, these 2 brake shoes 150b are disposed on both sides across the axle 16 a; and a lining 150c disposed on the brake drum 150a side of the brake shoe 150 b. In this case, when the 2 brake shoes 150b are separated from each other against the tensile force of the spring member 150d provided between the 2 brake shoes 150b, the linings 150c of the 2 brake shoes 150b press the brake drum 150a, respectively, and therefore, the rotation of the wheel portion 16b (rear wheel 16) to which the brake drum 150a is attached can be braked. Further, since drum brakes are well known, detailed description thereof will be omitted.

In the 4 th configuration, the swing arm 18 is provided with a breather pipe 148 (see fig. 2 to 4, 8, and 9) extending from the speed reducer housing portion 116. The breather pipe 148 is disposed above the reduction gear housing portion 116. Therefore, the breather pipe 148 is disposed between the motor 20 and the rear wheel 16, as in the reducer housing portion 116.

One end 148a of the breather pipe 148 as an inlet communicates with the reduction gear housing 116 in a state of being fixed to the transmission cover 154. The other end 148b of the breather pipe 148, which is an outlet, is disposed on the fender 60, and the fender 60 is located above the swing arm 18 and is swingable together with the swing arm 18. In this case, the other end 148b of the breather pipe 148 is inserted into a cylindrical fixing portion 168 provided on the left side surface of the fender 60, whereby the other end 148b is fixed to the fender 60. Therefore, the air pipe 148 is disposed in a state where one end 148a (inlet) is directed downward and the other end 148b (outlet) is directed upward.

As shown in fig. 8 and 9, an upper wall portion 170 extending in the front-rear direction is formed above the reduction gear housing portion 116 on the right side of the motor housing portion 98 c. The breather pipe 148 extends upward from the speed reducer housing portion 116, is bent forward along the upper wall portion 170, and is bent upward at the front end portion of the upper wall portion 170 and extends toward the fixing portion 168 of the fender 60. In this case, the upper wall portion 170 is inclined such that the other end 148b of the vent pipe 148 is higher than the one end 148 a. Therefore, the middle portion 148c of the vent pipe 148 disposed on the upper wall portion 170 is disposed on the upper wall portion 170 so as to be inclined so as to gradually increase in height as it moves forward. The upper wall portion 170 is provided with a fixing portion 172 such as a projection, and the fixing portion 172 such as a projection is projected upward to fix the vent pipe 148 to the upper wall portion 170 and a right side portion of the motor housing portion 98 c.

A plate member 174 extending in the vertical direction and the front-rear direction is integrally formed on the side surface of the front side of the fender 60. The other end 148b (outlet) of the vent pipe 148 is disposed on the left side of the plate member 174. Thus, the plate member 174 is disposed between the vent tube 148 and the rear wheel 16.

On the other hand, as shown in fig. 8, one end 148a (inlet) of the breather pipe 148 is disposed between the motor shaft 96 and the axle 16a, more specifically, between the intermediate shaft 156 and the axle 16 a.

< 2.5 modification >

Next, a modification of the present embodiment will be described with reference to fig. 10 to 15. These modifications are all modifications of the structure 1.

In modification 1 shown in fig. 10, a positioning pin 180 serving as a knock pin (knock-pin) is provided in one of the right rotor support portion 94R and the motor housing portion 98c in the left-right direction, and a positioning hole 182 into which the positioning pin 180 is fitted is provided in the other. Fig. 10 shows, as an example, a case where the motor housing portion 98c is provided with a positioning pin 180 and the rotor support portion 94R is provided with a positioning hole 182. Therefore, in modification 1, the long bolt 128 (see fig. 5) and the bolt hole 130 are screwed together with the positioning pin 180 fitted in the positioning hole 182.

Next, a modification 2 will be described with reference to fig. 11A to 12B. Modification 2 is a modification in which the shape of the spacer 122 is improved in order to fit the spacer 122 onto the motor shaft 96 by low-pressure press-fitting.

Fig. 11A shows a shim 184 according to a comparative example of modification 2. In the gasket 184 of the comparative example, a linear portion 122a substantially orthogonal to the radial direction of the gasket 184 is formed on one side of the inner peripheral portion of the gasket 184. Accordingly, shim 184 is asymmetrically shaped with respect to the center of shim 184. Accordingly, when the right end portion 96R of the motor shaft 96 is inserted into the spacer 184, the spacer 184 may be inclined with respect to the axial direction of the motor shaft 96.

Fig. 11B shows a spacer 122 according to the present embodiment. In the inner peripheral portion of the spacer 122, linear portions 122a substantially orthogonal to the radial direction of the spacer 122 are formed in 2 portions facing each other across the center of the spacer 122. Therefore, the spacer 122 has a shape substantially symmetrical with respect to the center of the spacer 122. Accordingly, the right end portion 96R of the motor shaft 96 can be inserted into the spacer 122 with a low-pressure press-fit while suppressing the inclination of the spacer 122 with respect to the axial direction of the motor shaft 96. In fig. 11B, the inner diameter side of the straight portion 122a may be formed into an arc-shaped curved portion.

In fig. 12A and 12B, a load reduction portion 122B formed of a through hole or a recess is provided near each linear portion 122A of the spacer 122. A perfect circle load alleviation portion 122B is illustrated in fig. 12A, and an oblong load alleviation portion 122B is illustrated in fig. 12B. By providing the load reducing portion 122b, it is possible to reduce the load generated when the right end portion 96R of the motor shaft 96 is inserted into the spacer 122, and to suppress the inclination of the spacer 122 with respect to the axial direction of the motor shaft 96. In the case of fig. 12A and 12B, the inner diameter side of the straight portion 122A may be formed into an arc-shaped curved portion.

Next, a modification 3 will be described with reference to fig. 13 to 15. The 3 rd modification is a modification of the method for improving the supply of the lubricant oil to the motor-side gear 120.

As shown in fig. 13 and 14A, in modification 3, a groove 120a through which lubricating oil passes is formed in the right side surface of the motor-side gear 120, that is, in an end surface (a side surface on the inner side in the vehicle width direction) of the motor-side gear 120 on the side of the pad 122, along the radial direction of the motor-side gear 120. Fig. 13 illustrates a case where 4 grooves 120a are formed in the radial direction at 90 ° intervals on the right side surface of the motor-side gear 120. Accordingly, the lubricating oil filled in the reducer housing 116 is supplied to the inner circumferential side and the outer circumferential side of the motor-side gear 120 via the groove 120a, and the motor-side gear 120 is uniformly lubricated by the lubricating oil. In addition, at least one groove 120a may be formed on the right side surface of the motor-side gear 120.

In modification 3, as shown in fig. 14B, at least one groove 120a may be formed in the radial direction of the motor-side gear 120 on the left side surface of the motor-side gear 120, that is, on the end surface (the outer side surface in the vehicle width direction) of the motor-side gear 120 on the motor housing 94 side. Of course, as in the case of fig. 13, also in the case of fig. 14B, 4 grooves 120a may be formed in the radial direction at 90 ° intervals on the left side surface of the motor-side gear 120.

In addition, in modification 3, as shown in fig. 15, a mechanism for actively supplying the lubricant oil to the motor-side gear 120 may be provided. Specifically, a supply hole 96a for supplying lubricating oil is provided in the right end portion 96R of the motor shaft 96. The supply hole 96a and a portion on the outer peripheral surface of the motor shaft 96 on the inner peripheral surface side of the motor-side gear 120 are communicated with each other by the communication hole 96 b. An oil passage 186 is provided for supplying lubricating oil from above or outside the reduction gear housing 116 to the supply hole 96 a. Accordingly, the lubricating oil supplied to the supply hole 96a via the oil passage 186 flows to the inner peripheral surface side of the motor-side gear 120 via the communication hole 96 b. The inner peripheral surface of the motor-side gear 120 and the outer peripheral surface of the motor shaft 96 are spline-processed, but there is a slight gap between these portions. The lubricating oil flows through these gaps in the groove 120a and reaches the outer peripheral surface of the motor-side gear 120. Accordingly, the motor-side gear 120 can be lubricated uniformly.

[3. effect of the present embodiment ]

The effects of the electrically powered vehicle 10 according to the present embodiment described above will be described in the order of the 1 st to 4 th configurations.

The electric vehicle 10 according to the present embodiment includes: a vehicle body frame 22; a pivot shaft 54 disposed on the vehicle body frame 22; a swing arm 18 having a front end (one end) rotatably supported by the pivot shaft 54 and a rear end (the other end) supporting the rear wheel 16; and a motor 20, which is disposed to the swing arm 18, for driving the rear wheel 16.

< 3.1 Effect of the 1 st Structure >

As the configuration 1, the electric vehicle 10 further includes a motor housing portion 98c, and the motor housing portion 98c is provided in the swing arm 18 and houses the motor 20. The motor 20 has: a stator 90; a rotor 92; and a motor housing 94 that houses the stator 90 in a fixed state, while rotatably housing the rotor 92 therein, and that fixes an opposing portion of the motor housing 94 that opposes the motor housing 98c to the motor housing 98 c.

Accordingly, in configuration 1, the motor 20 is disposed in the swing arm 18 only by fixing the motor housing 94 housing the stator 90 and the rotor 92 to the motor housing 98c, and therefore, the production efficiency of the electric vehicle 10 can be improved.

Further, a screw hole (1 st through hole) 124 facing the motor housing portion 98c is formed in the motor housing 94, and a bolt 128 is inserted into the screw hole 124, whereby an opposing portion of the motor housing 94 opposing the motor housing portion 98c is fixed to the motor housing portion 98 c. Accordingly, the motor housing 94 can be easily fixed to the motor housing 98 c.

The motor housing 94 also includes: rotor support portions 94L and 94R for rotatably supporting the rotor 92; and a stator support portion 94a that supports an outer side surface of the stator 90 in the radial direction of the motor 20. By causing stator support portion 94a and rotor support portions 94L and 94R to function as a part of motor housing 94, the number of parts of motor 20 can be reduced.

In addition, screw holes (2 nd through holes) 124 facing the motor housing portion 98c are formed in the rotor support portions 94L and 94R and the stator support portion 94a, and the rotor support portion 94R and a part of the stator support portion 94a form facing portions. In this case, the opposed portions are fixed to the motor housing portion 98c by inserting the bolts 128 into the screw holes 124. Accordingly, the motor housing 94 can be easily fixed to the motor housing 98c while reducing the number of parts of the motor 20.

A motor shaft 96 is rotatably supported by the rotor 92, and the motor shaft 96 projects from the motor housing 94 such that a right end portion (distal end portion) 96R faces the motor housing 98 c. Right end portion 96R of motor shaft 96 is rotatably supported by bearing 118, and bearing 118 is provided on the motor housing portion 98c side. Accordingly, the motor shaft 96 can be suitably supported by the motor housing 98 c.

In this case, spline machining is performed on the right end portion 96R side of the motor shaft 96, and a motor-side gear (gear) 120 for driving the axle 16a of the rear wheel 16 is inserted into the spline-machined portion. Further, a spacer 122 for preventing the slip-off is provided between the motor-side gear 120 and the bearing 118. Accordingly, the motor-side gear 120 can be prevented from being disengaged from the motor shaft 96.

Further, 2 portions of the inner peripheral portion of the spacer 122 facing each other across the center of the spacer 122 are each formed as a straight portion 122a orthogonal to the radial direction of the spacer 122. Accordingly, 2 linear portions 122a are provided symmetrically about the center of the spacer 122. As a result, when the spacer 122 is inserted into the motor shaft 96, the spacer 122 can be prevented from tilting in the axial direction of the motor shaft 96. Further, since the press-fitting load of the spacer 122 into the motor shaft 96 is reduced, the load on the operator can be reduced, and the spacer 122 can be press-fitted into the motor shaft 96 without using a tool such as a hammer or a device such as a spanner.

In this case, the load alleviation portions 122b, which are formed by through holes or recesses, may be provided at locations of the spacer 122 near the respective linear portions 122 a. This reduces the rigidity in the vicinity of the linear portion 122a, and can further reduce the press-fitting load of the spacer 122 on the motor shaft 96.

At least one groove 120a through which the lubricating oil passes may be formed in the end surface of the motor-side gear 120 on the side of the spacer 122 along the radial direction of the motor-side gear 120. This makes it possible to easily lubricate the motor-side gear 120 by supplying lubricating oil thereto. In addition, the occurrence of fretting can be suppressed.

In this case, at least one groove 120a may be formed in the motor-side gear 120 on the end surface on the motor housing 94 side. Accordingly, grooves 120a can be formed on both sides of the motor-side gear 120. As a result, the motor side gear 120 can be easily lubricated by the lubricating oil supplied through the grooves 120a provided on the left and right, while preventing the motor side gear 120 from being erroneously assembled with the motor shaft 96.

In addition, a supply hole 96a and a communication hole 96b may be formed on the motor shaft 96, wherein the supply hole 96a is used for supplying lubricating oil; the communication hole 96b communicates the supply hole 96a with a portion of the outer peripheral surface of the motor shaft 96 located on the inner peripheral surface side of the motor-side gear 120. Accordingly, the lubricating oil filled in the reducer housing 116 or the lubricating oil from the outside can be positively supplied to the supply hole 96a and also supplied to the motor-side gear 120 via the communication hole 96 b. As a result, the motor-side gear 120 can be lubricated more efficiently and reliably.

Further, a positioning pin 180 may be provided on one of the motor housing 94 and the motor housing 98c, and a positioning hole 182 into which the positioning pin 180 is fitted may be provided on the other. Accordingly, the screw holes 124 of the motor housing 94 and the bolt holes 130 of the motor housing 98c can be aligned easily and accurately. As a result, the long bolt 128 can be prevented from loosening after the motor housing 94 is fastened and fixed to the motor housing 98 c.

< 3.2 Effect of the 2 nd Structure >

In the 2 nd structure, the electric vehicle 10 further has a motor housing portion 98c, which motor housing portion 98c is provided to the swing arm 18 for housing the motor 20. The motor 20 has a motor housing 94, and the motor housing 94 houses the stator 90 and the rotor 92 as a driving portion of the motor 20. The swing arm 18 has a swing arm cover 102, and an exposure portion 132 that exposes a part of the motor housing 94 to the outside is provided in the swing arm cover 102.

Accordingly, in the configuration 2, the heat of the motor 20 is radiated to the outside through the exposed portion 132 provided in the swing arm cover 102. As a result, the motor 20 housed in the motor housing portion 98c of the swing arm 18 can be efficiently cooled.

In addition, the electric vehicle 10 further includes a power supply line 134, and the power supply line 134 supplies power to the motor 20. The swing arm cover 102 covers the power supply line 134. This can improve the design of the electric vehicle 10 while protecting the power supply line 134.

In this case, the power supply line 134 is disposed in front of the motor 20, and the swing arm cover 102 covers the power supply line 134 from the front. Accordingly, the power supply line 134 can be protected from flying stones and the like from the front while the electric vehicle 10 is traveling.

Motor 20 is a three-phase ac motor, and feeder 134 may be a three-phase wire for feeding power to the ac motor. This enables the electric vehicle 10 to travel satisfactorily.

The exposed portion 132 exposes the rear portion of the motor housing 94 to the outside. Accordingly, the motor 20 can be cooled while protecting the power feed line 134 from flying stones or the like from the front.

Further, exposed portion 132 exposes motor housing 94 to the outside in the vehicle width direction of electric vehicle 10. This can further improve the cooling efficiency of the motor 20.

The exposed portion 132 is formed to have a wider width toward the rear of the electric vehicle 10. Accordingly, the cooling efficiency of the motor 20 can be improved while protecting the interior of the swing arm 18 from flying stones and the like from the front.

The swing arm cover 102 covers a central portion of the motor housing 94 in a side view. This can protect the rotation angle detecting unit 112, the motor shaft 96, and the like.

The exposed portion 132 is formed in an arc shape in a side view. This enables the stator 90 constituting the motor 20 to be efficiently cooled.

The driving portion of the motor 20 is constituted by a stator 90 and a rotor 92, wherein the stator 90 is fixed inside a motor housing 94, and the rotor 92 is rotatably supported by a shaft inside the motor housing 94. Therefore, in configuration 2, the stator 90 and the rotor 92 can be cooled well.

The exposed portion 132 is provided to correspond to the slot 90b formed in the stator 90 and around which the coil 90c is wound, in a side view. This enables the stator 90 to be cooled more efficiently. That is, since the coil 90c is energized by the electric power supplied from the power supply line 134, the coil 90c is a component having the largest amount of heat generation in the motor 20. Therefore, by providing the exposed portion 132 corresponding to the coil 90c, the stator 90 can be cooled more efficiently.

Then, the motor housing 94 is fixed to the motor housing 98c via a bolt (fixing means) 128, whereby the motor 20 is housed in the motor housing 98 c. The exposure portion 132 exposes a part of the motor housing 94 to the outside so that the bolt 128 is covered by the swing arm cover 102. Accordingly, the bolt 128 can be concealed to improve the design of the electric vehicle 10 and cool the motor 20.

< 3.3 Effect of the 3 rd Structure >

In the 3 rd configuration, the electric vehicle 10 further includes: a motor housing portion 98c provided at a side of the rear wheel 16 in the swing arm 18 for housing the motor 20; and a power supply line 134 for supplying power to the motor 20. In this case, a through hole 138 is formed in a front end portion (one end portion 98a) of the swing arm 18 in a position forward of the rear wheel 16. The power supply line 134 extends forward from the motor 20 in the swing arm 18, is bent inward in the vehicle width direction of the electric vehicle 10 at one end 98a, and extends outward of the swing arm 18 from the through hole 138.

Accordingly, the power supply line 134 extends from the motor 20 to the outside through the through hole 138 formed in the one end portion 98a via the inside of the swing arm 18. As a result, when the feeder line 134 is disposed from the inside to the outside of the swing arm 18, the feeder line 134 can be disposed more linearly without bending the feeder line 134 too much. Further, since the degree of exposure of the power supply line 134 to the outside is low, the number of parts for protecting the power supply line 134 from the outside can be reduced and the appearance can be improved. Further, since a space above or below the swing arm 18 is secured, a space for mounting the battery 62 can be secured above the pivot shaft 54, for example. As a result, the minimum height above the ground of the swing arm 18 can be ensured.

Further, 2 bearings 100 are provided at both ends of the pivot shaft 54 in the vehicle width direction. One end portion 98a is rotatably supported on the pivot shaft 54 by 2 bearings 100. A through hole 138 is formed in the one end portion 98a at a position between the 2 bearings 100, and the power supply line 134 extends from between the 2 bearings 100 to the outside of the swing arm 18 via the through hole 138.

Thus, the power supply line 134 is not exposed to the outside at the outside in the vehicle width direction, but is exposed to the outside at the inside in the vehicle width direction. Accordingly, when the electric vehicle 10 is tilted during turning of the electric vehicle 10, the power feed line 134 is prevented from contacting the road surface, and therefore the tilt angle of the electric vehicle 10 can be secured.

The through hole 138 is formed in a portion of the one end portion 98a located above the pivot shaft 54, and the feeder line 134 extends from above the pivot shaft 54 to the outside of the swing arm 18 through the through hole 138. Accordingly, the minimum height above the ground of the electric vehicle 10 including the swing arm 18 can be ensured.

Further, a rib 146 is provided between the through hole 138 in the swing arm 18 and the motor housing portion 98 c. Accordingly, the mechanical strength of the swing arm 18 can be enhanced.

In addition, the electric vehicle 10 further includes: a rotation angle detection unit 112 that is disposed on the motor 20 and detects a rotation angle of the motor 20; and a communication line 136 extending from the rotation angle detecting unit 112. In this case, the communication line 136 extends forward from the rotation angle detecting unit 112 in the swing arm 18 along the power supply line 134, is bent inward in the vehicle width direction at the one end 98a, and extends outward of the swing arm 18 from the through hole 138. Accordingly, communication line 136 reduces bending in swing arm 18 together with power feeding line 134, and can improve appearance while avoiding exposure to the outside.

In addition, the electric vehicle 10 further includes a holder 142, and the holder 142 fixes the power supply line 134 to the swing arm 18 in the swing arm 18. Accordingly, the power supply line 134 arranged linearly inside the swing arm 18 can be held.

Further, a hole 144 for draining water is formed in the bottom of the swing arm 18. Accordingly, the liquid that has entered the swing arm 18 through the through hole 138 falls downward through the hole 144. As a result, the occurrence of short-circuiting or the like of the power feed line 134 due to liquid such as water can be avoided.

Further, the electric vehicle 10 includes a battery 62 and a PCU (electronic component) 66 supported by the vehicle body frame 22. The power supply line 134 is led out from the through hole 138 to the outside and connected to the PCU 66. The PCU66 supplies electric power supplied from the battery 62 to the motor 20 via the power supply line 134. Accordingly, the PCU66 can supply electric power to the motor 20 to drive the motor 20.

In this case, since the motor 20 is an ac motor and the power supply line 134 is a three-phase power line for supplying power to the ac motor, the electric vehicle 10 can be driven well.

< 3.4 Effect of the 4 th Structure >

In the 4 th configuration, the electric vehicle 10 includes a speed reducer 114 that transmits the driving force of the motor 20 to the rear wheels 16; a reducer housing unit 116 provided in the swing arm 18 and housing the reducer 114; and a vent pipe 148 extending from the reducer housing portion 116. One end 148a of the breather pipe 148 communicates with the reducer housing portion 116. The other end 148b of the breather pipe 148 is disposed on a fender 60 (a component of the electric vehicle 10) that is positioned above the swing arm 18 and is swingable together with the swing arm 18.

Accordingly, since the other end 148b of the breather pipe 148 is disposed upward, the lubricating oil liquefied in the breather pipe 148 returns to the reduction gear housing section 116 via the one end 148a of the breather pipe 148. As a result, the liquefied lubricant is not discharged to the outside, and therefore, contamination of the electric vehicle 10 and the like can be avoided.

The reduction gear housing 116 and the air pipe 148 are disposed between the motor 20 and the rear wheel 16. Accordingly, the space between the motor 20 and the rear wheel 16 can be effectively used.

The duct 148 is disposed along an upper wall portion 170, and the upper wall portion 170 is provided near the reducer housing portion 116 of the swing arm 18. Accordingly, the breather pipe 148 can be cooled by the traveling wind while protecting the breather pipe 148 from flying stones and the like during traveling of the electric vehicle 10. Further, by being disposed on the upper wall portion 170, even if the breather pipe 148 rattles due to vibration or the like during traveling, the breather pipe 148 can be prevented from coming into contact with the rear wheel 16.

In this case, the upper wall portion 170 is inclined such that the other end 148b of the vent pipe 148 is higher than the one end 148 a. Accordingly, even when the gas is liquefied into the lubricating oil by cooling the breather pipe 148, the lubricating oil returns from the one end portion 148a of the breather pipe 148 to the reduction gear housing 116. As a result, the lubricating oil can be prevented from being discharged to the outside from the other end 148b of the breather pipe 148.

Further, the upper wall portion 170 is provided with a fixing portion 172 for fixing the air pipe 148 to the swing arm 18 and the upper wall portion 170. Accordingly, the breather pipe 148 can be prevented from being involved in the rear wheel 16.

The vent pipe 148 is disposed in a state in which the other end 148b as an outlet is directed upward. This can reliably prevent the lubricating oil from being discharged to the outside from the outlet of the breather pipe 148.

The vent pipe 148 is disposed with the one end 148a as an inlet facing downward. Accordingly, the lubricating oil liquefied in the breather pipe 148 can be reliably returned to the speed reducer housing portion 116.

Further, the other end 148b of the breather pipe 148, which is an outlet, is disposed on the side surface of the fender 60. Accordingly, the other end 148b of the breather pipe 148 can be easily fixed.

In this case, a plate member 174 is disposed between the breather pipe 148 and the rear wheel 16. Accordingly, it is possible to avoid the breather pipe 148 from being involved in the rear wheel 16 when the other end portion 148b of the breather pipe 148 is detached from the fender 60, and to avoid the lubricating oil discharged from the outlet from adhering to the rear wheel 16.

The plate member 174 is integrally formed with the fender 60. Accordingly, the plate member 174 can be easily provided.

One end 148a of the breather pipe 148, which is an inlet, is provided between the motor shaft 96 of the motor 20 and an axle (output shaft) 16a, and the axle (output shaft) 16a transmits the driving force from the motor shaft 96 to the rear wheels 16. Accordingly, when the internal pressure rises due to the temperature rise in the reduction gear housing 116 and gas containing the atomized lubricating oil is generated, the gas can be efficiently discharged to the outside.

In this case, the inlet of the breather pipe 148 is provided between the intermediate shaft 156 of the speed reducer 114 and the axle 16a, wherein the speed reducer 114 transmits the driving force from the motor shaft 96 to the axle 16 a. Accordingly, the gas containing the mist of the lubricating oil can be discharged to the outside more efficiently.

The present invention has been described above with reference to preferred embodiments, but the technical scope of the present invention is not limited to the description of the above embodiments. It is obvious to those skilled in the art that various alterations and modifications can be added. It is obvious from the description of the embodiments that such additional modifications or improvements can be included in the technical scope of the present invention. In addition, the parenthesized reference numerals described in the claims are added to the reference numerals in the drawings for easy understanding of the present invention, and the present invention is not limited to the elements explained with the reference numerals.

Claims (9)

1. An electric vehicle (10) having a vehicle body frame (22), a pivot shaft (54), a swing arm (18), and a motor (20), wherein the pivot shaft (54) is provided to the vehicle body frame (22); one end of the swing arm (18) is rotatably supported on the pivot (54), the other end supports a rear wheel (16), the motor (20) is arranged on the swing arm (18) and is used for driving the rear wheel (16),

it is characterized in that the preparation method is characterized in that,

further provided with a motor housing part (98c), the motor housing part (98c) is arranged on the swing arm (18) and is used for housing the motor (20),

the motor (20) comprises a stator (90), a rotor (92), and a motor housing (94), wherein the motor housing (94) houses the stator (90) in a fixed state and houses the rotor (92) in a freely rotatable manner,

fixing a facing portion of the motor housing (94) facing the motor housing (98c) to the motor housing (98c),

a motor shaft (96) is rotatably supported on the rotor (92), the motor shaft (96) protrudes from the motor housing (94) with a tip end portion (96R) thereof facing the motor housing portion (98c),

a tip end portion (96R) of the motor shaft (96) is rotatably supported by a bearing (118) provided on the motor housing portion (98c) side,

spline processing is performed on the side of the tip end part (96R) of the motor shaft (96),

a gear (120) for driving an axle (16a) of the rear wheel (16) is inserted into a portion where the spline processing is performed,

a gasket (122) for preventing the gear from falling off is arranged between the gear (120) and the bearing (118),

2 parts of the inner peripheral portion of the gasket 122 facing each other across the center of the gasket 122 are each formed as a straight portion 122a orthogonal to the radial direction of the gasket 122.

2. The electric vehicle (10) of claim 1,

a 1 st through hole (124) is formed in the motor housing (94), the 1 st through hole (124) facing the motor housing (98c),

the facing portion of the motor housing (94) is fixed to the motor housing portion (98c) by inserting a bolt (128) through the 1 st through hole (124).

3. Electric vehicle (10) according to claim 1 or 2,

the motor housing (94) has rotor support parts (94L, 94R) and a stator support part (94a), wherein the rotor support parts (94L, 94R) rotatably support the rotor (92); the stator support portion (94a) supports a side surface of the stator (90) in a radial direction of the motor (20).

4. The electric vehicle (10) of claim 3,

a 2 nd through hole (124) is formed in the rotor support part (94L, 94R) and the stator support part (94a), the 2 nd through hole (124) facing the motor housing part (98c),

the rotor support part (94R) and a part of the stator support part (94a) are configured as the facing parts,

the opposite portion is fixed to the motor housing portion (98c) by inserting a bolt (128) through the 2 nd through hole (124).

5. Electric vehicle (10) according to claim 1 or 2,

a load reduction part (122b) comprising a through hole or a recess is provided in a portion of the gasket (122) located near each of the linear parts (122 a).

6. Electric vehicle (10) according to claim 1 or 2,

at least one groove (120a) through which lubricating oil passes is formed in the end surface of the gear (120) on the side of the pad (122) along the radial direction of the gear (120).

7. Electric vehicle (10) according to claim 6, characterized in that

At least one groove (120a) is formed in the gear (120) on the end surface on the motor housing (94) side along the radial direction of the gear (120).

8. The electric vehicle (10) of claim 6,

a supply hole (96a) and a communication hole (96b) are formed on the motor shaft (96), wherein the supply hole (96a) is used for supplying the lubricating oil; the communication hole (96b) communicates the supply hole (96a) with a portion of the outer peripheral surface of the motor shaft (96) on the inner peripheral surface side of the gear (120).

9. Electric vehicle (10) according to claim 1 or 2,

a positioning pin (180) is provided on one of the motor housing (94) and the motor housing (98c), and a positioning hole (182) that fits into the positioning pin (180) is provided on the other.

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