Electric vehicles

Abstract

The drive unit is positioned close to the steering gear unit. [Solution] The electric vehicle comprises a plurality of wheels including a pair of front wheels, a drive unit having a motor for driving the pair of front wheels and a housing for the motor, and a steering gear unit positioned in front of the vehicle relative to the drive unit and extending along the vehicle width direction, for steering the pair of front wheels. The front surface of one end of the housing in the vehicle width direction is a first displacement surface that displaces towards the rear of the vehicle as it extends outward in the vehicle width direction. The steering gear unit has a first projection that faces the first displacement surface of the housing from the front of the vehicle and also from the outside in the vehicle width direction.

Description

Technical Field

[0001] The technology disclosed in this specification relates to electric vehicles.

Background Art

[0002] Patent Document 1 describes an electric vehicle. This electric vehicle includes a plurality of wheels including a pair of front wheels, a drive unit having a motor, and a steering gear unit that is disposed in front of the drive unit in the vehicle front direction and extends along the vehicle width direction to steer the pair of front wheels.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In an electric vehicle as described above, by disposing the drive unit closer to the steering gear unit, it is possible to reduce the size of the space in which they are accommodated. However, if there is a portion that protrudes rearward of the vehicle in the steering gear unit, there is a risk that the protruding portion will interfere with the drive unit. In this case, it becomes difficult to dispose the drive unit closer to the steering gear unit.

[0005] ​​​​​​​​The technology disclosed herein is embodied in an electric vehicle. In a first embodiment, the electric vehicle comprises a plurality of wheels including a pair of front wheels, a drive unit having a motor for driving the pair of front wheels and a housing for the motor, and a steering gear unit positioned forward of the vehicle relative to the drive unit and extending along the vehicle width direction for steering the pair of front wheels. The front surface of one end of the housing in the vehicle width direction is a first displacement surface that displaces rearward from the vehicle as it extends outward in the vehicle width direction. The steering gear unit has a first projection that faces the first displacement surface of the housing from the front of the vehicle and also from the outside in the vehicle width direction.

[0007] In the electric vehicle described above, a first displacement surface is provided on the front surface of the drive unit housing. The first displacement surface is located at one end of the housing in the vehicle width direction and is displaced towards the rear of the vehicle as it extends outward in the vehicle width direction. The steering gear unit is provided with a first projection that aligns with the first displacement surface provided on the drive unit. The first projection faces the first displacement surface of the drive unit housing from the front of the vehicle and also from the outside in the vehicle width direction. With this configuration, the first projection of the steering gear unit overlaps with the drive unit housing in the vehicle longitudinal direction and also overlaps with the drive unit housing in the vehicle width direction. In other words, the first displacement surface provided on the drive unit is configured to be displaced towards the rear of the vehicle so as to avoid the first projection of the steering gear unit. As a result, even when the steering gear unit has a first projection, the drive unit can be positioned close to the steering gear unit.

[0008] In a second embodiment, the housing of the drive unit may comprise a housing body and a first cover attached to one end face of the housing body in the vehicle width direction, as in the first embodiment. In this case, the first displacement surface of the housing may be provided on the first cover. With this configuration, even if the first displacement surface is provided at the end of the housing, the motor and other components can be easily assembled into the housing body by removing the first cover from the housing body.

[0009] In a third embodiment, in the first or second embodiment, the steering gear unit may include a casing, a pinion shaft housed within the casing and rotatably supported, to which the steering shaft is connected, and a rack shaft housed within the casing and slidably supported along the vehicle width direction, which moves linearly in its own axial direction in response to the rotational movement of the pinion shaft. In this case, the first projection of the steering gear unit may be a part of the casing of the steering gear unit, specifically the portion housing the pinion shaft. With such a configuration, the portion of the casing of the steering gear unit that houses the pinion shaft can be allowed to protrude toward the rear of the vehicle.

[0010] In a fourth embodiment, in any of the first to third embodiments, the front surface at the other end of the housing in the vehicle width direction may be a second displacement surface that is displaced rearward as it moves outward in the vehicle width direction. With such a configuration, the drive unit can be positioned closer to the steering gear unit, whether the electric vehicle is right-hand drive or left-hand drive.

[0011] In a fifth embodiment, in any of the first to fourth embodiments, the steering gear unit may include a casing, a motor housed within the casing, a rack shaft housed within the casing and supported to be slidable along the vehicle width direction, and which moves linearly in its own axial direction in response to the rotational motion of the motor, and a transmission mechanism housed within the casing and interposed between the motor and the rack shaft. In this case, the first protrusion of the steering gear unit may be a part of the casing of the steering gear unit, specifically the part housing the transmission mechanism. With such a configuration, the part of the casing of the steering gear unit that houses the transmission mechanism can be allowed to protrude toward the rear of the vehicle.

[0012] In the sixth embodiment, in any of the first to fifth embodiments, the front surface of the other end of the housing in the vehicle width direction may be a second displacement surface that is displaced rearward from the vehicle as it extends outward in the vehicle width direction. In this case, the steering gear unit may have a second projection that faces the second displacement surface of the housing from the front of the vehicle and also from the outside in the vehicle width direction. With this configuration, the second displacement surface provided on the drive unit is displaced rearward from the vehicle so as to avoid the second projection of the steering gear unit. As a result, even if the steering gear unit has a second projection, the drive unit can be positioned closer to the steering gear unit.

[0013] In the seventh embodiment, in the sixth embodiment, the housing may comprise a housing body, a first cover attached to one end face of the housing body in the vehicle width direction, and a second cover attached to the other end face of the housing body in the vehicle width direction. In this case, the first displacement surface of the housing may be provided on the first cover. The second displacement surface of the housing may also be provided on the second cover. With this configuration, even if the first and second displacement surfaces are provided at both ends of the housing, the motor and other components can be easily assembled into the housing body by removing the first and second covers from the housing body.

[0014] In the eighth aspect, in the seventh aspect, the drive unit may further include an electrical unit that controls the power supplied to the motor. In this case, the housing may further include a third cover mounted across the rear surface of the first cover, the rear surface of the housing body, and the rear surface of the second cover. The electrical unit may then be located within the space defined by the first cover, the housing body, the second cover, and the third cover. This configuration allows for a larger space to accommodate the electrical unit compared, for example, when the third cover is mounted only on the rear surface of the housing body.

[0015] In the ninth aspect, in any of the sixth to eighth aspects, the steering gear unit may include a casing, a pinion shaft housed within the casing and rotatably supported, to which a steering shaft is connected, a motor housed within the casing, a rack shaft housed within the casing and slidably supported along the vehicle width direction, and which moves linearly in its own axial direction in response to the rotational motion of the pinion shaft and the motor, and a transmission mechanism housed within the casing and interposed between the motor and the rack shaft. In this case, the first projection of the steering gear unit may be a part of the casing of the steering gear unit that houses the pinion shaft. The second projection of the steering gear unit may be another part of the casing of the steering gear unit that houses the transmission mechanism. With such a configuration, the portion of the casing of the steering gear unit that houses the pinion shaft and the portion that houses the transmission mechanism can be allowed to protrude toward the rear of the vehicle. [Brief explanation of the drawing]

[0016] [Figure 1] A diagram schematically showing the configuration of the electric vehicle 10 of the embodiment. [Figure 2] A diagram showing the skeleton of the front drive unit 18. [Figure 3] A plan view illustrating the positional relationship between the front drive unit 18 and the steering gear unit 76. [Figure 4] A side view illustrating the positional relationship between the front drive unit 18 and the steering gear unit 76. [Figure 5] A front view illustrating the positional relationship between the front drive unit 18 and the steering gear unit 76. [Figure 6] An exploded view showing the housing 32 of the front drive unit 18. [Figure 7]A diagram schematically showing the configuration of the steering gear unit 76. The intermediate shaft 82 is also shown together.

Embodiments for Carrying out the Invention

[0017] Referring to the drawings, the electric vehicle 10 of the embodiment will be described. The electric vehicle 10 is a so-called automobile, which is a vehicle that travels on a road surface. The electric vehicle 10 is not limited to being operated by a user, and may be remotely operated by an external device or may perform autonomous driving.

[0018] Here, in the drawings, the direction FR indicates the front in the longitudinal direction (or the front-rear direction) of the electric vehicle 10, and the direction RR indicates the rear in the longitudinal direction of the electric vehicle 10. Also, the direction LH indicates the left in the vehicle width direction (or the left-right direction) of the electric vehicle 10, and the direction RH indicates the right in the vehicle width direction of the electric vehicle 10. Further, the direction UP indicates the upper side in the height direction (or the up-down direction) of the electric vehicle 10, and the direction DW indicates the lower side in the height direction of the electric vehicle 10.

[0019] As shown in FIG. 1, the electric vehicle 10 includes a vehicle body 12 and a plurality of wheels 14f, 14r. The vehicle body 12 has a passenger compartment 12c which is a space for carrying passengers. The plurality of wheels 14f, 14r are supported by the vehicle body 12. The plurality of wheels 14f, 14r are rotatably attached to the vehicle body 12. The plurality of wheels 14f, 14r include a pair of front wheels 14f located at the front of the vehicle body 12 and a pair of rear wheels 14r located at the rear of the vehicle body 12. The pair of front wheels 14f are arranged coaxially with each other, and the pair of rear wheels 14r are also arranged coaxially with each other. Note that the number of the wheels 14f, 14r is not limited to four. Also, although not particularly limited, the vehicle body 12 is made of a metal such as a steel material or an aluminum alloy.

[0020] As shown in FIG. 1, the electric vehicle 10 further includes a battery pack 16, a front drive unit 18, and a rear drive unit 20. The battery pack 16 incorporates, for example, a plurality of secondary battery cells and is configured to be rechargeable repeatedly by external power. The battery pack 16 supplies power to each of the front drive unit 18 and the rear drive unit 20. The battery pack 16 is disposed below the passenger compartment 12c. The front drive unit 18 is disposed at the front portion of the vehicle body 12. The rear drive unit 20 is disposed at the rear portion of the vehicle body 12.

[0021] The front drive unit 18 drives a pair of front wheels 14f, and the rear drive unit 20 drives a pair of rear wheels 14r. Although the pair of wheels 14f and 14r driven by the front drive unit 18 and the rear drive unit 20 are different, they have a common structure. Therefore, hereinafter, the configuration related to the front drive unit 18 will be described, and the description of the configuration related to the rear drive unit 20 will be omitted.

[0022] As shown in FIGS. 2-4, the electric vehicle 10 further includes a left front drive shaft 22 and a right front drive shaft 24. The left front drive shaft 22 is provided between the front drive unit 18 and one of the pair of front wheels 14f (i.e., the left front wheel 14f). The front drive unit 18 is connected to the left front wheel 14f via the left front drive shaft 22. The right front drive shaft 24 is provided between the front drive unit 18 and the other of the pair of front wheels 14f (i.e., the right front wheel 14f). The front drive unit 18 is connected to the right front wheel 14f via the right front drive shaft 24.

[0023] As shown in Figures 2 and 3, the front drive unit 18 comprises a motor 26, a gear mechanism 28, an electrical unit 30, a housing 32, a left output shaft 34, and a right output shaft 36. The motor 26 is a drive motor that drives a pair of front wheels 14f, and in this embodiment, it is a motor driven by three-phase AC power. The gear mechanism 28 distributes the driving force of the motor 26 to the pair of front wheels 14f. The motor 26 is connected to the left output shaft 34 and the right output shaft 36, respectively, via the gear mechanism 28. The left output shaft 34 is connected to the left front wheel 14f via the left front drive shaft 22. The right output shaft 36 is connected to the right front wheel 14f via the right front drive shaft 24. In this way, the motor 26 is connected to the pair of front wheels 14f via the gear mechanism 28, the output shafts 34 and 36, and the front drive shafts 22 and 24. This allows the motor 26 to drive the pair of front wheels 14f. In this embodiment, the motor 26 is arranged coaxially with the gear mechanism 28.

[0024] The electrical unit 30 controls the power supplied to the motor 26. In this embodiment, the electrical unit 30 has a built-in inverter and controls the power transmitted between the battery pack 16 and the motor 26. The electrical unit 30 is located behind the motor 26 and the gear mechanism 28. The electrical unit 30 may further include a DC-DC converter.

[0025] As shown in Figure 2-6, the housing 32 is a housing member. The housing 32 houses the motor 26, the gear mechanism 28, and the electrical unit 30. The housing 32 comprises a housing body 38, a first cover 40, a second cover 42, and a third cover 44. The housing body 38 has a first opening 38a and a second opening 38b. The first opening 38a is provided on one end face 38c in the vehicle width direction of the housing body 38 (i.e., the left end face 38c). The second opening 38b is provided on the other end face 38d in the vehicle width direction of the housing body 38 (i.e., the right end face 38d). As a result, the internal space of the housing body 38 is in communication with the outside of the housing body 38 at each of the left end face 38c and the right end face 38d. The first cover 40 is attached to the left end face 38c of the housing body 38 and closes the first opening 38a. The second cover 42 is attached to the right end face 38d of the housing body 38 and closes the second opening 38b. The motor 26 and the gear mechanism 28 are located in the space S1 defined by the first cover 40, the housing body 38, and the second cover 42.

[0026] The third cover 44 is mounted across the rear surface 40a of the first cover 40, the rear surface 38e of the housing body 38, and the rear surface 42a of the second cover 42. The electrical unit 30 is located within the space S2 defined by the first cover 40, the housing body 38, the second cover 42, and the third cover 44.

[0027] As shown in Figure 2, the motor 26 comprises a rotor 46, a stator 48, and a rotor shaft 50. The rotor 46 is supported in the housing 32 so as to be rotatable about a rotation axis R1. The stator 48 generally has a cylindrical shape with the rotation axis R1 as its central axis. The stator 48 is fixed to the inner wall of the housing 32. The stator 48 is located radially outward from the rotor 46. The rotor shaft 50 is connected to the rotor 46 and rotates together with the rotor 46. The rotor shaft 50 has a through hole 50a that extends along the direction of the rotation axis R1. The right output shaft 36 is located within the through hole 50a.

[0028] As shown in Figure 2, the gear mechanism 28 comprises a planetary gear mechanism 52 and a differential gear mechanism 54. The planetary gear mechanism 52 reduces the rotation of the rotor shaft 50 of the motor 26. The differential gear mechanism 54 distributes the torque of the motor 26 transmitted via the planetary gear mechanism 52 to a pair of front wheels 14f. In this embodiment, the differential gear mechanism 54 is arranged coaxially with the motor 26.

[0029] As shown in Figure 2, the planetary gear mechanism 52 comprises a sun gear 56, a plurality of stepped pinion gears 58, a ring gear 60, and a carrier 62. The sun gear 56 is connected to the rotor shaft 50 of the motor 26 and rotates together with the rotor shaft 50. Each of the plurality of stepped pinion gears 58 includes a large-diameter pinion gear 58a and a small-diameter pinion gear 58b. The diameter of the small-diameter pinion gear 58b is smaller than the diameter of the large-diameter pinion gear 58a. The large-diameter pinion gear 58a meshes with the sun gear 56. The small-diameter pinion gear 58b meshes with the ring gear 60. Each of the plurality of stepped pinion gears 58 can rotate on its own axis and revolve around the sun gear 56 and the ring gear 60. The ring gear 60 is fixed to the housing 32. The carrier 62 rotatably supports each of the multiple stepped pinion gears 58. The carrier 62 is also rotatably supported relative to the housing 32 around the rotation axis R1. As a result, the carrier 62 can rotate around the rotation axis R1 as the multiple stepped pinion gears 58 revolve.

[0030] As shown in Figure 2, the differential gear mechanism 54 comprises a differential case 64, a pinion shaft 66, differential pinion gears 68 and 70, a left side gear 72, and a right side gear 74. The differential case 64 is rotatably supported on the housing 32 around a rotation axis R1. The differential case 64 is connected to the carrier 62 of the planetary gear mechanism 52 and rotates together with the carrier 62. The pinion shaft 66, differential pinion gears 68 and 70, left side gear 72, and right side gear 74 are housed within the differential case 64.

[0031] The pinion shaft 66 is connected to the differential case 64 and rotates together with the differential case 64. The pinion shaft 66 extends in a direction perpendicular to the direction of the rotation axis R1. Each of the differential pinion gears 68 and 70 is rotatably supported relative to the pinion shaft 66, around the axis of the pinion shaft 66. The left side gear 72 and the right side gear 74 are coaxially arranged and face each other. The left side gear 72 meshes with each of the differential pinion gears 68 and 70. The left side gear 72 is connected to the left output shaft 34. The right side gear 74 meshes with each of the pair of differential pinion gears 68 and 70. The right side gear 74 is connected to the right output shaft 36.

[0032] The power transmission flow in the front drive unit 18 described above will now be explained. The rotational force of the rotor shaft 50 of the motor 26 is transmitted to the stepped pinion gear 58 as input to the rotation of the sun gear 56. The stepped pinion gear 58, having received the input, rotates on its own axis and revolves along the inner circumference of the fixed ring gear 60, receiving the reaction force of the ring gear 60. The revolving motion of the stepped pinion gear 58 is output as the rotation of the carrier 62. Within the differential case 64, which rotates together with the carrier 62, power is transmitted from the differential pinion gears 68 and 70 to the respective side gears 72 and 74. The power transmitted to each side gear 72 and 74 causes a corresponding front drive shaft 22 or 24 to rotate. Thus, in the front drive unit 18 of this embodiment, the sun gear 56 is the input element, the ring gear 60 is the reaction force element, and the carrier 62 is the output element.

[0033] Furthermore, the front drive unit 18 and the rear drive unit 20 may be equipped with other drive sources such as an engine in addition to the motor 26. Also, the electric vehicle 10 may be equipped with other power sources such as a fuel cell unit or solar panels in addition to, or instead of, the battery pack 16. Thus, the electric vehicle 10 is not limited to a battery-powered electric vehicle, but may be other types of electric vehicles such as hybrid vehicles, fuel cell vehicles, or solar cars.

[0034] As shown in Figure 1, the electric vehicle 10 comprises a steering gear unit 76, a steering wheel 78, and a steering shaft 80 including an intermediate shaft 82. The steering gear unit 76 steers a pair of front wheels 14f. The steering gear unit 76 is positioned in front of the vehicle relative to the front drive unit 18 and extends along the vehicle width direction. The steering wheel 78 is positioned in front of the driver's seat and is operated by the user. The steering shaft 80 transmits the steering operation by the user to the steering gear unit 76. The steering shaft 80 extends from the steering gear unit 76 toward the rear of the vehicle. In this embodiment, the electric vehicle 10 is left-hand drive, so the steering shaft 80 extends from the left side of the steering gear unit 76 toward the rear of the vehicle. The rear end of the steering shaft 80 is connected to the steering wheel 78. The front end of the steering shaft 80 is connected to the steering gear unit 76. As a result, the steering shaft 80 can transmit the rotational operation of the steering wheel 78, which is the steering operation performed by the user, to the steering gear unit 76. In other embodiments, the steering shaft 80 does not have to include the intermediate shaft 82 and may consist of a single shaft.

[0035] As shown in Figures 3-5 and 3-7, the steering gear unit 76 comprises a casing 84, a pinion shaft 86, a rack shaft 88, a motor 90, and a transmission mechanism 92. The casing 84 comprises a first casing 84a, a second casing 84b, a third casing 84c, and a fourth casing 84d. The casing 84 is composed of one or more casing members.

[0036] The pinion shaft 86 is housed within the first casing 84a and is rotatably supported within the first casing 84a. The pinion shaft 86 is connected to the steering shaft 80. In this embodiment, the rear end of the pinion shaft 86 is connected to the front end of the steering shaft 80. This allows the pinion shaft 86 to rotate in response to the user's rotational operation of the steering wheel 78. A pinion gear portion 86a is formed on the outer circumferential surface of the front end of the pinion shaft 86. The rack shaft 88 is housed within the second casing 84b and is slidably supported within the second casing 84b along the vehicle width direction. A rack gear portion 88a is formed on the outer circumferential surface of the rack shaft 88. The rack gear portion 88a meshes with the pinion gear portion 86a. This causes the rack shaft 88 to move linearly in the axial direction in response to the rotational motion of the pinion shaft 86. The linear motion of the rack shaft 88 is transmitted to the pair of front wheels 14f. Therefore, when the rack shaft 88 moves along the axial direction, the pair of front wheels 14f are steered. Tie rods and knuckles may be provided between the rack shaft 88 and the pair of front wheels 14f.

[0037] Motor 90 is a motor that serves as the drive source for the rack shaft 88, and in this embodiment, it is a motor driven by three-phase AC power. The rotation axis R2 of motor 90 is arranged parallel to the rack shaft 88. The operation of motor 90 is controlled by a control unit (not shown). By driving the rack shaft 88, motor 90 can assist the user in rotating the steering wheel 78. Furthermore, if the electric vehicle 10 is capable of autonomous driving, the rack shaft 88 can be driven without requiring the user to rotate the steering wheel 78. Motor 90 is housed in a third casing 84c.

[0038] The transmission mechanism 92 is interposed between the motor 90 and the rack shaft 88. The transmission mechanism 92 is configured to convert the rotational motion of the motor 90 into linear motion of the rack shaft 88. That is, as the motor 90 rotates, the rack shaft 88 moves along the axial direction. The specific configuration of the transmission mechanism 92 is not particularly limited. As an example, the transmission mechanism 92 of this embodiment comprises a belt mechanism 94 and a linear motion mechanism 96. The belt mechanism 94 is interposed between the motor 90 and the linear motion mechanism 96 and transmits the rotational motion of the motor 90 to the linear motion mechanism 96. The linear motion mechanism 96 is interposed between the belt mechanism 94 and the rack shaft 88 and converts the rotational motion input from the belt mechanism 94 into linear motion of the rack shaft 88. The belt mechanism 94 and the linear motion mechanism 96 are housed in a fourth casing 84d.

[0039] As shown in Figure 7, the belt mechanism 94 comprises a pair of pulleys 98, 100 and a belt 102. The belt 102 is wrapped between the pair of pulleys 98, 100. The pair of pulleys 98, 100 includes a drive pulley 98 and a driven pulley 100. The drive pulley 98 is connected to and driven by a motor 90. The driven pulley 100 is positioned coaxially with the rack shaft 88. Although not particularly limited, the diameter of the driven pulley 100 is larger than the diameter of the drive pulley 98. Thus, the belt mechanism 94 also functions as a reduction gear.

[0040] As shown in Figure 7, the linear motion mechanism 96 comprises a ball nut 104, a plurality of balls 106, and a bearing 108. The ball nut 104 has a cylindrical shape. The ball nut 104 is arranged to surround the rack shaft 88. A driven pulley 100 is fixed coaxially to the ball nut 104. As a result, the ball nut 104 rotates in conjunction with the rotation of the driven pulley 100. A groove 104a is formed on the inner circumferential surface of the ball nut 104. A groove 88b is formed on the outer circumferential surface of the rack shaft 88. The plurality of balls 106 are arranged between the groove 104a of the ball nut 104 and the groove 88b of the rack shaft 88. As a result, the ball nut 104 is screwed onto the rack shaft 88 via the plurality of balls 106. The ball nut 104 is rotatably supported by the bearing 108 relative to the fourth casing 84d.

[0041] In the transmission mechanism 92 described above, when the motor 90 rotates, the drive pulley 98 rotates. The rotation of the drive pulley 98 is transmitted to the driven pulley 100 via the belt 102, causing the driven pulley 100 and the ball nut 104 to rotate. In this embodiment, since the diameter of the driven pulley 100 is larger than the diameter of the drive pulley 98, the rotational speed of the driven pulley 100 and the ball nut 104 is slower than the rotational speed of the drive pulley 98. The rotational speed of the drive pulley 98 relative to the rotational speed of the driven pulley 100 and the ball nut 104 changes according to the ratio of the diameter of the drive pulley 98 to the diameter of the driven pulley 100. Since the ball nut 104 rotates relative to the rack shaft 88, the multiple balls 106 interposed between the ball nut 104 and the rack shaft 88 receive a load from the ball nut 104 and the rack shaft 88 and circulate indefinitely within the rolling path A. As the ball 106 circulates indefinitely, the torque applied to the ball nut 104 is converted into a force applied to the rack shaft 88 in the axial direction. In this way, the rack shaft 88 moves linearly in the axial direction relative to the ball nut 104 in response to the rotational motion of the motor 90. This axial force applied to the rack shaft 88 becomes an assist force, which helps to steer the pair of front wheels 14f.

[0042] As shown in Figure 3-5, the steering gear unit 76 has a first projection 77a. The first projection 77a is mainly composed of a first casing 84a, and a pinion shaft 86 is housed inside it. In contrast, as shown in Figure 3-6, the front surface 33 of the housing 32 of the front drive unit 18 has a first displacement surface 33a. The first displacement surface 33a is located at one end of the housing 32 in the vehicle width direction (i.e., the left end) and is displaced towards the rear of the vehicle as it moves outward in the vehicle width direction. The first projection 77a is positioned to match the first displacement surface 33a provided on the front drive unit 18. Specifically, the first projection 77a faces the first displacement surface 33a of the housing 32 of the front drive unit 18 from the front of the vehicle and also from the outside in the vehicle width direction.

[0043] According to the above configuration, the first protrusion 77a of the steering gear unit 76 overlaps with the housing 32 of the front drive unit 18 in the vehicle longitudinal direction and also overlaps with the housing 32 of the front drive unit 18 in the vehicle width direction. That is, the first displacement surface 33a provided on the front drive unit 18 is configured to displace towards the rear of the vehicle so as to avoid the first protrusion 77a of the steering gear unit 76. As a result, even when the first protrusion 77a is present on the steering gear unit 76, the front drive unit 18 can be positioned closer to the steering gear unit 76.

[0044] The first protrusion 77a of the steering gear unit 76 is not limited to a specific location. As mentioned above, in this embodiment, the first protrusion 77a is part of the casing 84 of the steering gear unit 76, and the pinion shaft 86 is housed inside it. With this configuration, the portion of the casing 84 of the steering gear unit 76 that houses the pinion shaft 86 can be allowed to protrude toward the rear of the vehicle. Generally, in a steering gear unit 76, the pinion shaft 86 is often provided to protrude toward the rear of the vehicle. Therefore, with the above configuration, the pinion shaft 86 can be allowed to protrude toward the rear of the vehicle.

[0045] As shown in Figures 3 and 5, the steering gear unit 76 has a second projection 77b. The second projection 77b is mainly composed of a fourth casing 84d, which houses the transmission mechanism 92. In contrast, as shown in Figure 3-6, the front surface 33 of the housing 32 of the front drive unit 18 has a second displacement surface 33b. The second displacement surface 33b is located at the other end of the housing 32 in the vehicle width direction (i.e., the right end) and is displaced towards the rear of the vehicle as it moves outward in the vehicle width direction. The second projection 77b is positioned to match the second displacement surface 33b provided on the front drive unit 18. Specifically, the second projection 77b faces the second displacement surface 33b of the housing 32 of the front drive unit 18 from the front of the vehicle and also from the outside in the vehicle width direction.

[0046] The second protrusion 77b of the steering gear unit 76 overlaps with the housing 32 of the front drive unit 18 in the vehicle longitudinal direction and also overlaps with the housing 32 of the front drive unit 18 in the vehicle width direction. That is, the second displacement surface 33b provided on the front drive unit 18 is configured to displace towards the rear of the vehicle so as to avoid the second protrusion 77b of the steering gear unit 76. As a result, even when the second protrusion 77b is present on the steering gear unit 76, the front drive unit 18 can be positioned closer to the steering gear unit 76.

[0047] The second projection 77b of the steering gear unit 76 is not limited to a specific location. As described above, in this embodiment, the second projection 77b is part of the casing 84 of the steering gear unit 76, and the transmission mechanism 92 is housed inside it. With this configuration, the portion of the casing 84 of the steering gear unit 76 that houses the transmission mechanism 92 can be allowed to protrude toward the rear of the vehicle.

[0048] In this embodiment, the steering gear unit 76 has a first protrusion 77a and a second protrusion 77b. In contrast, the front surface 33 of the housing 32 of the front drive unit 18 has a first displacement surface 33a facing the first protrusion 77a and a second displacement surface 33b facing the second protrusion 77b. With this configuration, the portion of the casing 84 of the steering gear unit 76 that houses the pinion shaft 86 and the portion that houses the transmission mechanism 92 can be allowed to protrude toward the rear of the vehicle.

[0049] However, the steering gear unit 76 does not necessarily have to have both the first projection 77a and the second projection 77b. In other embodiments, the steering gear unit 76 may have only one of the first projection 77a and the second projection 77b. In other words, the steering gear unit 76 may consist of only one of the pinion shaft 86 and the transmission mechanism 92.

[0050] Furthermore, even if the steering gear unit 76 has only a first protrusion 77a that accommodates the pinion shaft 86, the front surface 33 of the housing 32 of the front drive unit 18 may have both a first displacement surface 33a and a second displacement surface 33b. With such a configuration, the front drive unit 18 can be positioned close to the steering gear unit 76, whether the electric vehicle 10 is right-hand drive or left-hand drive.

[0051] However, the front surface 33 of the housing 32 of the front drive unit 18 does not necessarily have to have both the first displacement surface 33a and the second displacement surface 33b. In other embodiments, the front surface 33 of the housing 32 of the front drive unit 18 may have only one of the first displacement surface 33a and the second displacement surface 33b. In this case, one of the displacement surfaces of the front drive unit 18 may face the protrusion of the steering gear unit 76.

[0052] In this embodiment, the first displacement surface 33a of the housing 32 is provided on the first cover 40. With this configuration, even if the first displacement surface 33a is provided at the end of the housing 32, by removing the first cover 40 from the housing body 38, the internal space of the housing body 38 is largely opened to the outside through the first opening 38a (see Figure 6). This makes it easy to assemble the motor 26 and other components into the housing body 38.

[0053] In this embodiment, in addition to the above, the second displacement surface 33b of the housing 32 is provided on the second cover 42. With this configuration, even if the first displacement surface 33a and the second displacement surface 33b are provided at both ends of the housing 32, the internal space of the housing body 38 is largely opened to the outside through the second opening 38b (see Figure 6) by removing the first cover 40 and the second cover 42 from the housing body 38. This makes it easy to assemble the motor 90 and other components inside the housing body 38.

[0054] In this embodiment, the front drive unit 18 and the rear drive unit 20 have a common structure. However, the front drive unit 18 and the rear drive unit 20 do not necessarily have a common structure. That is, in other embodiments, the rear drive unit 20 may have a different structure from the front drive unit 18, insofar as it drives a pair of rear wheels 14r.

[0055] In this embodiment, the electric vehicle 10 includes a front drive unit 18 and a rear drive unit 20. However, the electric vehicle 10 does not necessarily need to include a rear drive unit 20. That is, in other embodiments, the electric vehicle 10 may include only a front drive unit 18.

[0056] Although several specific examples have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes to the specific examples illustrated above. The technical elements described in this specification or in the drawings exhibit technical usefulness individually or in combination. [Explanation of symbols]

[0057] 10: Electric vehicle, 12: Body, 14f, 14r: Wheels, 16: Battery pack, 18: Front drive unit, 20: Rear drive unit, 22, 24: Front drive shaft, 26: Motor, 28: Gear mechanism, 30: Electrical unit, 32: Housing, 33: Front, 33a: First displacement surface, 33b: Second displacement surface, 34, 36: Output shaft, 38: Housing body, 40: First cover, 42: Second cover, 44: Third cover, 76: Steering gear unit, 77a: First protrusion, 77b: Second protrusion, 78: Steering wheel, 80: Steering shaft, 82: Intermediate shaft, 84: Casing, 86: Pinion shaft, 88: Rack shaft, 90: Motor 92: Transmission mechanism, 94: Belt mechanism, 96: Linear motion mechanism

Claims

1. It is an electric vehicle, Multiple wheels, including a pair of front wheels, A drive unit having a motor that drives the pair of front wheels and a housing that houses the motor, A steering gear unit is positioned in front of the vehicle relative to the drive unit and extends along the vehicle width direction, and steers the pair of front wheels, Equipped with, The front surface at one end of the housing in the vehicle width direction is a first displacement surface that displaces towards the rear of the vehicle as it extends outward in the vehicle width direction. The steering gear unit has a first projection that faces the first displacement surface of the housing from the front of the vehicle and also from the outside in the vehicle width direction. Electric vehicle.

2. The housing comprises a housing body and a first cover attached to one end face of the housing body in the vehicle width direction. The electric vehicle according to claim 1, wherein the first displacement surface of the housing is provided on the first cover.

3. The steering gear unit is, Casing and, Housed within the aforementioned casing, rotatably supported, and connected to the steering shaft is a pinion shaft, The rack shaft is housed within the casing, is supported to be slidable along the vehicle width direction, and moves linearly in its own axial direction in response to the rotational motion of the pinion shaft, The electric vehicle according to claim 1, wherein the first protrusion of the steering gear unit is a part of the casing of the steering gear unit and houses the pinion shaft.

4. The electric vehicle according to claim 1, wherein the front surface at the other end of the housing in the vehicle width direction is a second displacement surface that is displaced towards the rear of the vehicle as it is directed outward in the vehicle width direction.

5. The steering gear unit is, Casing and, The motor housed within the casing, A rack shaft is housed within the casing, is supported so as to be slidable along the vehicle width direction, and moves linearly in its own axial direction in response to the rotational motion of the motor, The transmission mechanism is housed within the casing and interposed between the motor and the rack shaft, The electric vehicle according to claim 1, wherein the first protrusion of the steering gear unit is a part of the casing of the steering gear unit and houses the transmission mechanism.

6. The front surface at the other end of the housing in the vehicle width direction is a second displacement surface that displaces towards the rear of the vehicle as it extends outward in the vehicle width direction. The electric vehicle according to claim 1, wherein the steering gear unit has a second projection that faces the second displacement surface of the housing from the front of the vehicle and also from the outside in the vehicle width direction.

7. The aforementioned housing is It comprises a housing body, a first cover attached to one end face of the housing body in the vehicle width direction, and a second cover attached to the other end face of the housing body in the vehicle width direction. The first displacement surface of the housing is provided on the first cover, The electric vehicle according to claim 6, wherein the second displacement surface of the housing is provided on the second cover.

8. The drive unit further comprises an electrical unit that controls the power supplied to the motor, The housing further comprises a third cover attached across the rear surface of the first cover, the rear surface of the housing body, and the rear surface of the second cover. The electric vehicle according to claim 7, wherein the electrical unit is located within the space defined by the first cover, the housing body, the second cover, and the third cover.

9. The steering gear unit is, Casing and, Housed within the aforementioned casing, rotatably supported, and connected to the steering shaft is a pinion shaft, The motor housed within the casing, A rack shaft is housed within the casing, is supported so as to be slidable along the vehicle width direction, and moves linearly in its own axial direction in response to the rotational motion of the pinion shaft and the rotational motion of the motor, The transmission mechanism is housed within the casing and interposed between the motor and the rack shaft, The first protrusion of the steering gear unit is part of the casing of the steering gear unit and is the portion that houses the pinion shaft. The electric vehicle according to claim 6, wherein the second projection of the steering gear unit is another part of the casing of the steering gear unit, and houses the transmission mechanism.

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