Electric vehicles

Abstract

In an electric vehicle (10), a rear wheel (24) is arranged in an offset manner with respect to a motor (38) so as to be away from a second side cover (56) in a left-right direction. A first side cover (54) is closer to the rear wheel (24) than the second side cover (56) is, and has a greater fixation force with respect to an outer rotor (52) than the second side cover.

Description

[Technical Field]

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

[0002] Japanese Patent No. 5875883 discloses an electric vehicle equipped with drive wheels and a motor. The motor is disposed inside the drive wheels and at the center of the drive wheels in the vehicle width direction. Summary of the Invention

[0003] A drive wheel has a tire and a rim that holds the tire. To inflate the tire, a valve must be placed inside the rim. However, in the electric vehicle disclosed in Japanese Patent No. 5875883, the motor is placed at the center of the drive wheel in the vehicle width direction, making it difficult to secure space for the valve.

[0004] The present invention aims to solve the above-mentioned problems.

[0005] An aspect of the present invention is an electric vehicle comprising a drive wheel and a motor that drives the drive wheel, wherein the drive wheel has a tire and a rim portion that holds the tire, and the motor has a rotating shaft portion that extends in the vehicle width direction of the electric vehicle, a stator fixed to the rotating shaft portion, an outer rotor fixed to the rim portion and rotating integrally with the rim portion, a first side cover fixed to a first end of the outer rotor in the vehicle width direction and supporting the outer rotor rotatably relative to the rotating shaft portion, and a second side cover fixed to a second end of the outer rotor in the vehicle width direction and supporting the outer rotor rotatably relative to the rotating shaft portion, wherein the drive wheel is positioned offset from the motor so as to be away from the second side cover in the vehicle width direction, and the first side cover is closer to the drive wheel than the second side cover and has a greater fixing force on the outer rotor than the second side cover.

[0006] In this invention, the drive wheels are positioned offset in the vehicle width direction relative to the motor. This allows space to be secured for arranging valves. Furthermore, the fastening force of the first side cover, which is close to the drive wheels, to the outer rotor is greater than the fastening force of the second side cover to the outer rotor. This prevents the first side cover from coming off due to vibration of the drive wheels. Furthermore, because the fastening force of the second side cover to the outer rotor is not excessive, the electric vehicle, including the motor, can be made lighter and more compact. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a left side view of an electric vehicle according to this embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] Fig. 1 is a left side view of an electric vehicle 10 according to this embodiment. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. In the following explanation, the direction in which the electric vehicle 10 moves forward is defined as the forward direction, and the front-rear, left-right, and up-down directions will be explained.

[0009] The electric vehicle 10 is a saddle-ride type vehicle such as a two-wheeled vehicle. The electric vehicle 10 includes a body frame 12. The body frame 12 has a pivot frame 14 and a rear frame 16. A pivot shaft 18 is connected to the pivot frame 14 in the left-right direction (vehicle width direction). The left end of the pivot shaft 18 is journaled to the front part of a left swing arm 20L. The right end of the pivot shaft 18 is journaled to the front part of a right swing arm 20R.

[0010] A shaft 22 (rotating shaft) is fixed to the rear of the swing arms 20L, 20R. A rear wheel 24 is rotatably supported on the shaft 22. The shaft 22 is a solid shaft. The rear of the swing arms 20L, 20R are suspended from the rear frame 16 by rear cushion units 26L, 26R. A seat 28 on which a passenger sits is disposed above the rear cushion units 26L, 26R. The seat 28 is supported by the rear frame 16.

[0011] The body frame 12 is covered with a body cover 30. A battery 32 is disposed inside the body cover 30 and below the seat 28. The battery 32 is supported by the rear frame 16. A PCU (power control unit) 36 is disposed inside the body cover 30 and below a step floor 34. The PCU 36 is supported by the body frame 12. A motor 38 is disposed inside the rear wheel 24. The motor 38 is an in-wheel motor.

[0012] The rear wheel 24 has a tire 40 and a wheel 42. The wheel 42 has a rim portion 44. The rim portion 44 is provided on the outer periphery of the wheel 42. The rim portion 44 supports the tire 40. A motor 38 is disposed inside the rim portion 44.

[0013] The motor 38 is disposed to be offset to the right with respect to the rear wheels 24. In other words, the rear wheels 24 are disposed to be offset to the left with respect to the motor 38. Therefore, a center line 46 of the motor 38 in the vehicle width direction is offset to the right with respect to a center line 48 of the rear wheels 24 in the vehicle width direction. The center line 48 of the rear wheels 24 is the center line of the electric vehicle 10 in the vehicle width direction.

[0014] The motor 38 includes a shaft 22 , a stator 50 , an outer rotor 52 , a first side cover 54 , and a second side cover 56 .

[0015] The shaft 22 passes through the center of the wheel 42 and extends in the left-right direction. The left end of the shaft 22 is journaled on the rear part of the left swing arm 20L. The right end of the shaft 22 is journaled on the rear part of the right swing arm 20R. The shaft 22 is the rotation shaft of the rear wheel 24 and the motor 38.

[0016] The stator 50 is fixed to the shaft 22 inside the rim portion 44. The stator 50 is formed in a disk shape. The center of the stator 50 in the left-right direction is located on the center line 46 of the motor 38. A coil 58 is wound around the radially outer portion of the stator 50.

[0017] The outer rotor 52 is disposed opposite the stator 50. The outer rotor 52 is formed in a cylindrical shape. The outer rotor 52 extends in the left-right direction. The left-right center of the outer rotor 52 is located on the center line 46 of the motor 38. A magnet 60 is disposed on the inner circumferential surface of the outer rotor 52 so as to face the stator 50. In the following description, the left end of the outer rotor 52 is referred to as a first end 62. The right end of the outer rotor 52 is referred to as a second end 64.

[0018] A rim portion 44 is fixed to the outer rotor 52. Specifically, the central portion 66 of the rim portion 44 is fixed to the outer rotor 52 with a central portion 66 in the vehicle width direction of the rim portion 44 in surface contact with a portion of the outer peripheral surface of the outer rotor 52 that is close to the first end portion 62. The central portion 66 of the rim portion 44 is located on the center line 48 of the rear wheel 24. Therefore, the motor 38 is offset to the right with respect to the rear wheel 24 so that the central portion 66 of the rim portion 44 is fixed to a portion of the outer rotor 52 that is close to the first end portion 62.

[0019] The first side cover 54 is a disk-shaped member. The first side cover 54 is fixed to the first end 62 of the outer rotor 52 so as to close the opening on the left side of the outer rotor 52. Specifically, the first side cover 54 is fixed to the first end 62 of the outer rotor 52 by first fastening portions 68. The first fastening portions 68 are first bolts 70. The first bolts 70 fasten the first side cover 54 to the first end 62 of the outer rotor 52. More specifically, the first side cover 54 is fastened to the first end 62 of the outer rotor 52 by a plurality of first bolts 70.

[0020] The second side cover 56 is a disk-shaped member. The second side cover 56 is fixed to the second end 64 of the outer rotor 52 so as to close the opening on the right side of the outer rotor 52. Specifically, the second side cover 56 is fixed to the second end 64 of the outer rotor 52 by second fastening portions 74. The second fastening portions 74 are second bolts 76. The second bolts 76 fasten the second side cover 56 to the second end 64 of the outer rotor 52. More specifically, the second side cover 56 is fastened to the second end 64 of the outer rotor 52 by a plurality of second bolts 76.

[0021] The rear wheel 24 is disposed offset to the left with respect to the motor 38 so as to be away from the second side cover 56. Therefore, the first side cover 54 is disposed closer to the rear wheel 24 than the second side cover 56. In addition, the outer rotor 52, the first side cover 54, and the second side cover 56 form an internal space 78 in the motor 38 for accommodating the stator 50.

[0022] A first bearing 80 is interposed between the first side cover 54 and the shaft 22. As a result, the first side cover 54 supports the outer rotor 52 and the rear wheel 24 rotatably relative to the shaft 22. A second bearing 82 is interposed between the second side cover 56 and the shaft 22. As a result, the second side cover 56 supports the outer rotor 52 and the rear wheel 24 rotatably relative to the shaft 22.

[0023] A brake 84 is provided on the left side of the first side cover 54. The brake 84 may be provided at a location closer to the first side cover 54 than the center line 48 of the rear wheel 24.

[0024] A valve hole 86 is formed in the rim portion 44. The valve hole 86 is formed in a portion of the rim portion 44 that is closer to the first side cover 54 than the center line 48 of the rear wheel 24. Specifically, the valve hole 86 is formed in a portion of the rim portion 44 to the left of the center portion 66 and closer to the first side cover 54. A valve 88 is inserted into the valve hole 86. The valve 88 is a component that allows air supplied from an air supply source (not shown) to enter the tire 40.

[0025] A through hole 90 is formed in the shaft 22, which connects the interior of the right swing arm 20R to the internal space 78. An electric power line 92 is inserted through the through hole 90. One end of the electric power line 92 is connected to the PCU 36. The electric power line 92 is introduced from the PCU 36 through the right swing arm 20R and the through hole 90 into the internal space 78 of the motor 38. The other end of the electric power line 92 is connected to the coil 58. Therefore, the electric power line 92 is disposed on the opposite side of the center line 48 of the rear wheel 24 from the position where the valve hole 86 is formed.

[0026] As described above, the motor 38 is offset to the right with respect to the rear wheel 24. This makes it easy to ensure space for inserting the valve 88 into the valve hole 86.

[0027] The battery 32 also supplies DC power to the PCU 36. The PCU 36 converts the DC power supplied from the battery 32 into three-phase AC power. The PCU 36 supplies the converted AC power to the coil 58 of the motor 38 via a power line 92. The outer rotor 52 rotates when AC power is supplied to the coil 58. As a result, the rear wheel 24, including the rim portion 44 fixed to the outer rotor 52, rotates about the shaft 22. As a result, the electric vehicle 10 travels.

[0028] Furthermore, as indicated by the solid arrows in FIG. 2 , when a downward load is applied to the shaft 22 due to, for example, an occupant sitting on the seat 28 (see FIG. 1 ), the load is transmitted to the ground contact surface of the rear wheel 24 via the first side cover 54, the second side cover 56, and the rear wheel 24. A reaction force against the load acts upward from the ground contact surface to the rear wheel 24, as indicated by the open arrows. The reaction force is transmitted from the rim portion 44 of the rear wheel 24 to the motor 38. As described above, the motor 38 is offset rightward with respect to the rear wheel 24. The rim portion 44 is fixed to a portion close to the first end portion 62 of the outer rotor 52. Therefore, a large reaction force acts on the first fixing portion 68, which fixes the first end portion 62 of the outer rotor 52 to the first side cover 54.

[0029] Therefore, in the electric vehicle 10 according to this embodiment, the fixing force of the first side cover 54 to the outer rotor 52 is set to be greater than the fixing force of the second side cover 56 to the outer rotor 52. This prevents the first side cover 54 close to the center line 48 of the rear wheel 24 from coming off due to vibration of the rear wheel 24. In addition, the fixing force of the second side cover 56 away from the center line 48 of the rear wheel 24 is not excessively large. As a result, the electric vehicle 10, including the motor 38, can be made lighter and more compact.

[0030] Specifically, the fixing force between the first side cover 54 and the outer rotor 52 by the first fixing portion 68 may be made greater than the fixing force between the second side cover 56 and the outer rotor 52 by the second fixing portion 74 .

[0031] Specifically, the head diameter of the first bolt 70 serving as the first fixing portion 68 may be made larger than the head diameter of the second bolt 76 serving as the second fixing portion 74. This makes the fastening force (fixing force) between the first side cover 54 and the outer rotor 52 by the first bolt 70 larger than the fastening force (fixing force) between the second side cover 56 and the outer rotor 52 by the second bolt 76.

[0032] Alternatively, the diameter of the threaded portion of the first bolt 70 may be larger than the diameter of the threaded portion of the second bolt 76. Even in this case, the fastening force between the first side cover 54 and the outer rotor 52 by the first bolt 70 can be larger than the fastening force between the second side cover 56 and the outer rotor 52 by the second bolt 76.

[0033] Furthermore, the number of the first bolts 70 may be greater than the number of the second bolts 76. Even in this case, the fastening force between the first side cover 54 and the outer rotor 52 by the first bolts 70 is greater than the fastening force between the second side cover 56 and the outer rotor 52 by the second bolts 76.

[0034] In the above description, the motor 38 is offset to the right relative to the rear wheels 24. In the electric vehicle 10 according to this embodiment, it is sufficient that the rear wheels 24, which serve as drive wheels, are offset from the motor 38 in the left-right direction. Therefore, the rear wheels 24 may be offset to the right relative to the motor 38. In other words, the motor 38 may be offset to the left relative to the rear wheels 24.

[0035] In the above description, the first fixing portion 68 is the first bolt 70, and the second fixing portion 74 is the second bolt 76. In this embodiment, it is sufficient that the first fixing portion 68 can fix the first side cover 54 to the first end 62 of the outer rotor 52, and the second fixing portion 74 can fix the second side cover 56 to the second end 64 of the outer rotor 52. Therefore, the first fixing portion 68 may be an adhesive that fixes the first side cover 54 to the first end 62 of the outer rotor 52, and the second fixing portion 74 may be an adhesive that fixes the second side cover 56 to the second end 64 of the outer rotor 52. Alternatively, the first fixing portion 68 may be an engaging member that engages the first side cover 54 to the first end 62 of the outer rotor 52, and the second fixing portion 74 may be an engaging member that engages the second side cover 56 to the second end 64 of the outer rotor 52.

[0036] The invention that can be understood from the above-described embodiments will be described below.

[0037] According to one aspect of the present invention, there is provided an electric vehicle (10) including a drive wheel (24) and a motor (38) that drives the drive wheel (24), wherein the drive wheel (24) has a tire (40) and a rim portion (44) that holds the tire (40), and the motor (38) includes a rotary shaft portion (22) that extends in a vehicle width direction of the electric vehicle (10), a stator (50) fixed to the rotary shaft portion (22), an outer rotor (52) that is fixed to the rim portion (44) and rotates integrally with the rim portion (44), and a stator (50) fixed to a first end (62) of the outer rotor (52) in the vehicle width direction and that rotates the outer rotor (52) relative to the rotary shaft portion (22). and a second side cover (56) fixed to a second end (64) of the outer rotor (52) in the vehicle width direction and rotatably supporting the outer rotor (52) relative to the rotating shaft portion (22), the drive wheels (24) are arranged offset with respect to the motor (38) so as to be away from the second side cover (56) in the vehicle width direction, the first side cover (54) is closer to the drive wheels (24) than the second side cover (56) and has a greater fixing force with respect to the outer rotor (52) than the second side cover (56).

[0038] In this invention, the drive wheels are positioned offset in the vehicle width direction relative to the motor. This allows space to be secured for arranging valves. Furthermore, the fastening force of the first side cover, which is close to the drive wheels, to the outer rotor is greater than the fastening force of the second side cover to the outer rotor. This prevents the first side cover from coming off due to vibration of the drive wheels. Furthermore, because the fastening force of the second side cover to the outer rotor is not excessive, the electric vehicle, including the motor, can be made lighter and more compact.

[0039] In one aspect of the present invention, the motor (38) further has a first fixing portion (68) for fixing the first side cover (54) and the outer rotor (52) together, and a second fixing portion (74) for fixing the second side cover (56) and the outer rotor (52), and the fixing force between the first side cover (54) and the outer rotor (52) by the first fixing portion (68) is greater than the fixing force between the second side cover (56) and the outer rotor (52) by the second fixing portion (74).

[0040] This makes it possible to easily obtain the above-mentioned effects.

[0041] In one aspect of the present invention, the first fixing portion (68) is a first bolt (70) for fastening the first side cover (54) and the outer rotor (52), and the second fixing portion (74) is a second bolt (76) for fastening the second side cover (56) and the outer rotor (52), and the head diameter of the first bolt (70) may be larger than the head diameter of the second bolt (76).

[0042] This makes it possible to differentiate the fixing force of the first fixing portion from the fixing force of the second fixing portion with a simple configuration.

[0043] In one aspect of the present invention, the first fixing portion (68) is a first bolt (70) for fastening the first side cover (54) and the outer rotor (52), and the first side cover (54) is fixed to the outer rotor (52) by a plurality of the first bolts (70), the second fixing portion (74) is a second bolt (76) for fastening the second side cover (56) and the outer rotor (52), and the second side cover (56) is fixed to the outer rotor (52) by a plurality of the second bolts (76), and the number of the plurality of first bolts (70) may be greater than the number of the plurality of second bolts (76).

[0044] This makes it possible to differentiate the fixing force of the first fixing portion from the fixing force of the second fixing portion with a simple configuration.

[0045] In an aspect of the present invention, the rim portion (44) is formed with a valve hole (86) for inserting a valve (88) for inflating the tire (40), and the valve hole (86) may be formed in a portion of the rim portion (44) that is closer to the first side cover (54) than the center (48) of the drive wheel (24) in the vehicle width direction.

[0046] Since the motor is disposed offset from the drive wheels, it is easy to ensure space for disposing the valve inside the drive wheels.

[0047] In an aspect of the present invention, a brake (84) may be disposed at a position closer to the first side cover (54) than the center (48) of the drive wheel (24) in the vehicle width direction.

[0048] This makes it easy to ensure space for arranging the brake inside the drive wheels, which in turn allows for a more compact electric vehicle.

[0049] In an embodiment of the present invention, the rim portion (44) may be formed with a valve hole (86) for inserting a valve (88) for inflating the tire (40), and a power line (92) for supplying power to the motor (38) may be positioned on the opposite side of the center (48) of the drive wheel (24) in the vehicle width direction from the position where the valve hole (86) is formed.

[0050] Since the power lines are arranged close to the motor arranged at an offset, the overall length of the power lines can be shortened.

[0051] 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.

Claims

1. An electric vehicle (10) comprising a drive wheel (24) and a motor (38) for driving the drive wheel (24), The drive wheel (24) has a tire (40) and a rim portion (44) that holds the tire (40), The motor (38) a rotating shaft portion (22) extending in the vehicle width direction of the electric vehicle (10); a stator (50) fixed to the rotating shaft portion (22); an outer rotor (52) fixed to the rim portion (44) and rotating integrally with the rim portion (44); a first side cover (54) fixed to a first end (62) of the outer rotor (52) in the vehicle width direction and supporting the outer rotor (52) rotatably with respect to the rotating shaft portion (22); a second side cover (56) fixed to a second end (64) of the outer rotor (52) in the vehicle width direction and supporting the outer rotor (52) rotatably with respect to the rotating shaft portion (22); a first fixing portion (68) for fixing the first side cover (54) and the outer rotor (52); a second fixing portion (74) for fixing the second side cover (56) and the outer rotor (52); and The drive wheel (24) is disposed offset from the motor (38) in the vehicle width direction so as to be spaced apart from the second side cover (56), the first side cover (54) is closer to the drive wheel (24) than the second side cover (56); a fixing force between the first side cover (54) and the outer rotor (52) by the first fixing portion (68) is greater than a fixing force between the second side cover (56) and the outer rotor (52) by the second fixing portion (74); the first fixing portion (68) is a first bolt (70) for fastening the first side cover (54) and the outer rotor (52), the second fixing portion (74) is a second bolt (76) for fastening the second side cover (56) and the outer rotor (52), The electric vehicle (10) has a head diameter of the first bolt (70) larger than a head diameter of the second bolt (76).

2. 2. The electric vehicle (10) according to claim 1, the first side cover (54) is fixed to the outer rotor (52) by a plurality of the first bolts (70); the second side cover (56) is fixed to the outer rotor (52) by a plurality of the second bolts (76); The number of the plurality of first bolts (70) is greater than the number of the plurality of second bolts (76).

3. (delete)

4. An electric vehicle (10) comprising a drive wheel (24) and a motor (38) for driving the drive wheel (24), The drive wheel (24) has a tire (40) and a rim portion (44) that holds the tire (40), The motor (38) a rotating shaft portion (22) extending in the vehicle width direction of the electric vehicle (10); a stator (50) fixed to the rotating shaft portion (22); an outer rotor (52) fixed to the rim portion (44) and rotating integrally with the rim portion (44); a first side cover (54) fixed to a first end (62) of the outer rotor (52) in the vehicle width direction and supporting the outer rotor (52) rotatably with respect to the rotating shaft portion (22); a second side cover (56) fixed to a second end (64) of the outer rotor (52) in the vehicle width direction and supporting the outer rotor (52) rotatably with respect to the rotating shaft portion (22); a first fixing portion (68) for fixing the first side cover (54) and the outer rotor (52); a second fixing portion (74) for fixing the second side cover (56) and the outer rotor (52); and The drive wheel (24) is disposed offset from the motor (38) in the vehicle width direction so as to be spaced apart from the second side cover (56), the first side cover (54) is closer to the drive wheel (24) than the second side cover (56); a fixing force between the first side cover (54) and the outer rotor (52) by the first fixing portion (68) is greater than a fixing force between the second side cover (56) and the outer rotor (52) by the second fixing portion (74); the first fixing portion (68) is a first bolt (70) for fastening the first side cover (54) and the outer rotor (52), the first side cover (54) is fixed to the outer rotor (52) by a plurality of the first bolts (70); the second fixing portion (74) is a second bolt (76) for fastening the second side cover (56) and the outer rotor (52), the second side cover (56) is fixed to the outer rotor (52) by a plurality of the second bolts (76); The number of the plurality of first bolts (70) is greater than the number of the plurality of second bolts (76).

5. 5. The electric vehicle (10) according to claim 4, The electric vehicle (10) has a head diameter of the first bolt (70) larger than a head diameter of the second bolt (76).

6. The electric vehicle (10) according to any one of claims 1, 2, 4 and 5, The rim portion (44) is formed with a valve hole (86) for inserting a valve (88) for inflating the tire (40), The valve hole (86) is formed in a portion of the rim portion (44) that is closer to the first side cover (54) than to a center (48) of the drive wheel (24) in the vehicle width direction.

7. 7. The electric vehicle (10) according to claim 6, The electric vehicle (10) has a brake (84) disposed at a position closer to the first side cover (54) than to a center (48) of the drive wheel (24) in the vehicle width direction.

8. The electric vehicle (10) according to any one of claims 1, 2, 4 and 5, The rim portion (44) is formed with a valve hole (86) for inserting a valve (88) for inflating the tire (40), an electric power line (92) that supplies power to the motor (38) is arranged on the opposite side of the position where the valve hole (86) is formed with respect to the center (48) of the drive wheel (24) in the vehicle width direction.

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