JP5877080B2 - Electric vehicle drive unit - Google Patents

Description

  The present invention relates to a drive unit for an electric vehicle.

  In recent years, the development of electric vehicles using a motor as a power source in place of an engine has been actively developed. In such an electric vehicle, the motor is used to drive the wheels.

  A technique related to a vehicle body structure of an electric vehicle is disclosed in Japanese Unexamined Patent Application Publication No. 2009-286303 (Patent Document 1). Patent Document 1 discloses a vehicle body structure of an electric vehicle in which a pair of left and right motors whose rotating shafts are substantially aligned in the vehicle width direction are arranged. The left and right wheels are driven by the left and right motors attached to the vehicle body. The drive system disclosed in Patent Document 1 is so-called on-board drive.

JP 2009-286303 A

  In the electric vehicle represented by Patent Document 1, as a drive unit of the electric vehicle for driving the left and right wheels, in addition to the pair of left and right motors, the left and right wheels, and the pair of left and right motors and the left and right wheels are respectively connected. There is a pair of drive shafts. The drive unit of the electric vehicle transmits the rotational force of each motor to the left and right wheels via the drive shaft to obtain the drive force as the electric vehicle.

  In addition, the drive unit of the electric vehicle having the above-described configuration including the motor has an oil tank for storing lubricating oil circulating inside the motor, and pumps the lubricating oil from the lower part of the oil tank and supplies it to the motor. And an oil pump for circulating inside. The oil tank is usually located in the lower area of the motor. Lubricating oil is circulated inside the motor using an oil tank and an oil pump. In addition, each member which comprises the drive unit of an electric vehicle is mainly attached to the lower area | region of a vehicle body in consideration of the positional relationship with the tire of the wheel grounded on a road surface.

  In the drive unit of the electric vehicle having the above-described configuration, the axis of the motor rotation shaft, that is, the output shaft that outputs the rotation of the motor, and the axis of the wheel rotation shaft are approximately on the same straight line in the vehicle width direction. It is desirable to be located. However, if the position of the axis of the rotating shaft of the motor that touches the road surface is aligned with the vertical position of the axis of the rotating shaft of the wheel, the mounting position of the motor in the vertical direction is relatively It will be lower. Then, when the vehicle travels on a rough road with a large degree of unevenness on the road surface, the contact between the oil tank arranged in the lowermost region and the road surface among the constituent members of the drive unit of the electric vehicle may occur.

  Here, in order to secure the minimum height of the oil tank from the road surface, that is, the so-called minimum ground clearance, it is conceivable to position the motor on the upper side. In this case, since the wheel and the motor are connected with a certain large angle, it is conceivable to use a joint member that allows a predetermined angle at the time of connection, such as a constant velocity joint. That is, the wheel rotation shaft close to the road surface and the motor rotation shaft positioned relatively above are connected by a constant velocity joint, and the motor rotation shaft with respect to the wheel rotation shaft is held at a predetermined angle to This is a system that transmits the power of

  However, in such a constant velocity joint, when the angle formed by the rotation axis of the wheel and the rotation axis of the motor is increased, the strength of the constant velocity joint, specifically, the strength of the outer ring that is a constituent member of the constant velocity joint is increased. The life of the constant velocity joint itself may be shortened. This decrease in strength and short life of the constant velocity joint tends to become more prominent as the angle between the wheel rotation shaft and the motor rotation shaft increases. Therefore, even when a constant velocity joint is used, it is preferable that the axis of the rotation axis of the wheel and the axis of the rotation axis of the motor be arranged as close as possible to the same straight line.

  Also, increase the radial dimension of the tire that constitutes the wheel to make it a large-diameter wheel, raise the position of the wheel rotation shaft in the vertical direction relatively, and rotate the axis of the wheel rotation shaft and the motor. It is also conceivable to secure the minimum ground clearance of the oil tank while realizing the disposition at a position close to the same straight line as the shaft center. However, in this case, the mounting position of the motor is also located on the upper side, and adopting a tire having an unnecessarily large diameter for such a vehicle case is limited to the upper region of the vehicle body. The vehicle space is occupied, which is not preferable. Moreover, it is preferable to avoid also from the point that the cost increase accompanying the enlargement of a tire or a wheel arises.

  An object of the present invention is to provide a drive unit for an electric vehicle that realizes low cost and long life while ensuring a wide vehicle body space.

An electric vehicle drive unit according to the present invention is an electric vehicle drive unit that drives wheels by rotation of a motor. The drive unit of the electric vehicle is disposed in the lower region of the vehicle body and in the central region of at least one of the front side and the rear side of the vehicle body in the vehicle width direction, and the respective rotation shafts are directed substantially in the vehicle width direction. A pair of motors, a pair of wheels disposed in an end region in the vehicle width direction, respectively driven by rotation of each motor, each motor and each wheel extending along the axis of the rotation shaft of the motor A pair of drive shafts, a pair of cases each having a predetermined volume, a pair of oil tanks capable of storing therein lubricating oil for lubricating each motor, and each oil A pair of oil pumps is provided that draws lubricating oil from suction ports provided in the lower part of the tank, supplies it to each motor, and circulates the lubricating oil inside each motor. That. Here, each oil tank is attached to the motor so as to be adjacent to the side of the motor in the vehicle width direction or the vehicle front-rear direction, and the position avoiding the lower region of the rotation shaft of each motor Is provided.

  According to the configuration of the drive unit of such an electric vehicle, each oil tank is provided at a position that avoids the lower region of the rotation shaft of each motor, so that the vertical position of the motor is lowered. The axis of the wheel rotation shaft and the axis of the motor rotation shaft can be arranged at a position close to the same straight line. Therefore, low cost and long life can be achieved while ensuring a wide vehicle space.

  Further, the position where each oil tank is provided may include a rear side of each motor.

  Further, the position where each oil tank is provided may be configured to include the front side of each motor.

  Further, the position where each oil tank is provided may be configured to include a region located in the vehicle width direction of each motor.

  Further, the vertical position of the vehicle body in which the suction port is provided may be configured to be a region between the bottom wall located at the lowest part of the oil tank and 1/3 of the internal height of the oil tank.

  The motor may be configured to include a speed reducer that decelerates the rotation of the motor.

  Further, the position where the oil tank is provided may include a lower region of the speed reducer.

  Moreover, the structure by which the under guard is attached to the lower area | region of at least any one motor may be sufficient.

  According to the configuration of the drive unit of such an electric vehicle, each oil tank is provided at a position that avoids the lower region of the rotation shaft of each motor, so that the vertical position of the motor is lowered. The axis of the wheel rotation shaft and the axis of the motor rotation shaft can be arranged at a position close to the same straight line. Therefore, low cost and long life can be achieved while ensuring a wide vehicle space.

It is the schematic which shows the drive unit of the electric vehicle which concerns on one Embodiment of this invention. It is sectional drawing which shows a part of drive unit of the electric vehicle which concerns on one Embodiment of this invention shown in FIG. It is a figure which shows schematically one motor and oil tank which are contained in the drive unit of the electric vehicle which concerns on one Embodiment of this invention shown in FIG. It is a figure which shows schematically the inside of one motor and the inside of an oil tank which are contained in the drive unit of the electric vehicle which concerns on one Embodiment of this invention shown in FIG. It is sectional drawing which shows a part of drive unit of the electric vehicle in which the oil tank was provided in the lower area | region of the rotating shaft of the motor. FIG. 6 is a diagram schematically showing one motor and an oil tank included in the drive unit of the electric vehicle shown in FIG. 5. It is a figure which shows roughly the one motor and oil tank which are contained in the drive unit of the electric vehicle which concerns on other embodiment of this invention. It is sectional drawing which shows a part of drive unit of the electric vehicle which concerns on further another embodiment of this invention. It is sectional drawing which shows a part of drive unit of the electric vehicle which concerns on further another embodiment of this invention.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing a drive unit of an electric vehicle according to an embodiment of the present invention. Note that the vertical direction of the electric vehicle corresponds to the front and back direction of FIG. FIG. 1 corresponds to a view seen from the lower side of the electric vehicle. Incidentally, the upward direction of the paper surface indicated by the arrow A ₁ in FIG. 1, the front side, i.e., the traveling direction of the electric vehicle. Moreover, let the paper surface left-right direction in FIG. 1 be the vehicle width direction of a vehicle body. That is, the vehicle body in the vehicle width direction is the direction perpendicular to the direction indicated by the arrow A _1.

  First, referring to FIG. 1, an electric vehicle drive unit 11 according to an embodiment of the present invention includes a pair of left and right front wheels 13a and 13b provided on the front side of a vehicle body as steering wheels and a rear side of the vehicle body as drive wheels. A pair of left and right rear wheels 14a, 14b provided on the side, a pair of left and right motors 15a, 15b provided corresponding to the pair of rear wheels 14a, 14b, the left rear wheel 14a and the left motor 15a, the right side A pair of left and right drive shafts 16a and 16b for connecting the rear wheel 14b and the right motor 15b are provided. The front wheels 13a and 13b and the rear wheels 14a and 14b are respectively disposed in the end region 17b in the vehicle width direction. The drive unit 11 of the electric vehicle is configured to include four wheels.

  The chassis 12 constituting the vehicle body has a substantially rectangular shape that is long in the vertical direction on the paper surface in FIG. The region corresponding to the position where the pair of front wheels 13a and 13b and the pair of rear wheels 14a and 14b are provided is in the vehicle width direction so as to receive the pair of front wheels 13a and 13b and the pair of rear wheels 14a and 14b. The shape is recessed on the vehicle body center side.

  The pair of motors 15a and 15b is disposed in a lower region of the vehicle body and in a central region 17a in the vehicle width direction on the rear side of the vehicle body. The pair of motors 15a and 15b are provided such that the axis 18 of each of the rotation shafts 19a and 19b indicated by a one-dot chain line is directed substantially in the vehicle width direction. In this case, the axis 18 of the rotating shaft 19a of the motor 15a and the axis 18 of the rotating shaft 19b of the motor 15b are shown overlappingly. The above-described central region 17a is a region located between both end regions 17b and shows a relative positional relationship.

  The pair of rear wheels 14a and 14b are driven by the rotation of the pair of motors 15a and 15b. The motor 15a is connected to the drive shaft 16a via a rotating shaft 19a of the motor 15a serving as an output shaft. A constant velocity joint 20a is provided on the side of the motor 15a of the drive shaft 16a. A constant velocity joint 20b is provided on the rear wheel 14a side of the drive shaft 16a. By these constant velocity joints 20a and 20b, even if the angle formed between the rotating shaft 19a of the motor 15a and the drive shaft 16a is an angle other than 0 degrees, power can be transmitted following the inclination. Similarly, the motor 15b is connected to the drive shaft 16b via a rotating shaft 19b serving as an output shaft. A constant velocity joint 20c is provided on the motor 15b side of the drive shaft 16b, and a constant velocity joint 20d is provided on the rear wheel 14b side of the drive shaft 16b.

  The configuration of the motor 15a will be briefly described as follows. Although not shown, the motor 15a includes a stator fixed to the housing, a rotor disposed at a position facing the inner side of the stator with a radial gap, and a rotor fixedly connected to the inner side of the rotor. And a rotating member that rotates integrally. The motor 15a is a so-called radial gap motor. Since the motor 15b has the same configuration, the description thereof is omitted.

  The drive unit 11 of the electric vehicle having such a configuration has two motors, that is, one motor is provided for one drive wheel and is driven by a pair of left and right motors. Can be driven independently. Therefore, it is possible to improve the motion performance, maneuverability, and riding comfort of the vehicle by the control. In addition, since the motor is mounted on the vehicle body side and the drive wheels are driven using a drive shaft, the so-called unsprung load is light and a general suspension shape can be used. The degree of freedom is high.

FIG. 2 is a sectional view showing a part of the drive unit 11 of the electric vehicle according to the embodiment of the present invention shown in FIG. FIG. 2 shows the case of cutting along the section indicated by the arrow II-II in FIG. FIG. 2 corresponds to a case where the shaft 12 is cut by a cross section including the axis 18 of the rotation shafts 19 a and 19 b and extending in the vertical direction of the chassis 12. FIG. 3 schematically shows one motor 15a and an oil tank 21a, which will be described later, included in the drive unit of the electric vehicle according to the embodiment of the present invention shown in FIG. FIG. 3 shows the motor 15a and the oil tank 21a located on the left side in FIG. Figure 3 is a view from the left side of the chassis 12 shown by an arrow A ₂ in Fig. FIG. 4 is a cross-sectional view schematically showing the inside of the motor 15a and the inside of the oil tank 21a shown in FIG. For even 4, it is a view from the left side of the chassis 12 shown by an arrow A ₂ in Fig.

  Referring to FIGS. 1 to 4, drive unit 11 of the electric vehicle is composed of cases each having a predetermined volume, and lubricating oil for lubricating motors 15 a and 15 b is stored therein. A pair of possible left and right oil tanks 21a, 21b and a pair of oil pumps 22a, 22b provided in the respective oil tanks 21a, 21b and circulating the lubricating oil inside the respective motors 15a, 15b are provided. The pair of oil pumps 22a and 22b draws lubricating oil from suction ports provided in the lower portions of the oil tanks 21a and 21b, and supplies them to the motors 15a and 15b. In FIG. 1, the pair of oil pumps 22a and 22b is schematically shown by dotted lines. The pair of oil pumps 22a and 22b is not shown in FIGS. 2 and 3 from the viewpoint of easy understanding. In this case, the oil level of the lubricating oil stored in the oil tank 21a is preferably positioned below the axis 18 of the rotating shaft 19a of the motor 15a.

  Here, the oil tank 21a will be described. The left oil tank 21a is provided at a position avoiding the lower region 23a of the rotating shaft 19a of the motor 15a. Specifically, the position where the oil tank 21a is provided is a side portion on the rear side of the motor 15a. That is, the position where the oil tank 21a is provided includes the rear side of the motor 15a. In this case, the oil tank 21a has a shape extending to the rear side of the motor 15a. Similarly, for the right oil tank 21b, the right oil tank 21b is provided at a position avoiding the lower region of the rotating shaft 19b of the motor 15b. Specifically, the position where the oil tank 21b is provided is a side portion on the rear side of the motor 15b. That is, the position where the oil tank 21b is provided includes the rear side of the motor 15b. In this case, the shape of the oil tank 21b is also a shape extending to the rear side of the motor 15b, similar to the oil tank 21a.

  In this way, each oil tank 21a, 21b is provided at a position avoiding the lower region of the rotation shafts 19a, 19b of each motor 15a, 15b, so that the vertical positions of the motors 15a, 15b are lowered. Thus, the axis of the rotation shafts of the rear wheels 14a and 14b and the axis 18 of the rotation shafts 19a and 19b of the motors 15a and 15b can be arranged at positions close to the same straight line. Therefore, low cost and long life can be realized while widening the vehicle body space.

  This will be described. FIG. 5 is a cross-sectional view showing a part of the drive unit of the electric vehicle in which the oil tank is provided in the lower region of the rotation shaft of the motor. 6 is a diagram schematically showing one motor and an oil tank included in the drive unit of the electric vehicle shown in FIG. FIG. 5 corresponds to the cross section shown in FIG. FIG. 6 corresponds to the cross section shown in FIG.

First, referring to FIG. 5 and FIG. 6, in the drive unit 31 of the electric vehicle, an oil tank 33a is provided below the motor 32a. In this case, the height H ₄ from the road surface 24 to the portion 34a located closest to the bottom of the oil tank 33a, in order to ensure a minimum ground clearance, to place the motor 32a on the upper side of the vehicle body in the vertical direction There is a need. In this case, the rotating shaft 40a of the motor 32a and the drive shaft 36a are connected via a constant velocity joint 37a, and the rear wheel 35a and the drive shaft 36a are connected via a constant velocity joint 37b. The motor 32a can be arranged with a certain angle. Angle in this case is the axis 38a of the rotary shaft of the wheel 35a after indicated by the one-dot chain line in FIG. 5, the angle B ₁ of the axis 39a of the drive shaft 36a shown in two-dot chain line in FIG. 5 . Here, if the angle B ₁ is increased, the constant velocity joint 37a, or decrease the strength of 37b, there is a possibility that the life is shortened.

Next, referring again to FIGS. 1 to 4, according to the configuration of the drive unit 11 of the electric vehicle shown in FIG. 1, the lowermost portion 25 a of the motor 15 a from the road surface 24 shown in FIG. 2. With respect to the height H ₁ up to, the angle corresponding to the so-called angle B ₁ can be almost 0 degrees while ensuring the minimum ground clearance. That is, the axis of the rotating shaft of the rear wheel 14a and the axis 18 of the rotating shaft 19a of the motor 15a can be disposed at a position close to the same straight line while lowering the vertical position of the motor 15a.

  In this case, since the positions where the oil tanks 21a and 21b are provided are the side portions on the rear side of the motors 15a and 15b, even if the lubricating oil is biased to the rear side during sudden acceleration of the electric vehicle, it is more reliable. In addition, the lubricating oil can be sucked by the oil pumps 22a and 22b. When the electric vehicle is decelerated, it is considered that there is no particular problem because the torque of the motors 15a and 15b is small and the load is light.

Here, with respect to the suction port 26a provided at the tip of the oil passage 30a, which is a route through which the lubricating oil 29a sucked up from the oil tank 21a is supplied into the motor 15a, the position of the vehicle body in the vertical direction where the suction port 26a is provided. may be a region between the bottom wall 27a located at the lowest portion of the oil tank 21a to 1/3 of the internal height H ₂ of up to the top wall 28a located at the top of the oil tank 21a. That is, when the height _{H 3} of the vertical height of the vehicle body from the bottom wall 27a to the suction port _26a, constituting to have the relationship of _{H 3 <H 2 × 1/} 3. By doing so, the lubricating oil 29a can be more reliably sucked from the suction port 26a, and the lubricating oil 29a can be circulated in the motor 15a stably.

  In the above embodiment, the oil tank is provided at the rear side of the motor. However, the present invention is not limited to this, and the oil tank is provided at the front side of the motor. You may comprise so that it may be a part. That is, the position where the oil tank is provided may be configured to include the front side of the motor.

  FIG. 7 is a diagram schematically showing one motor and an oil tank included in the drive unit 41 of the electric vehicle in this case. FIG. 7 corresponds to the cross section shown in FIG. In the drive unit 41 of the electric vehicle, illustration of the components other than the one motor, the oil tank, and the rotating shaft is omitted, but the basic configuration is the same as the drive unit of the electric vehicle shown in FIG.

  Referring to FIG. 7, a drive unit 41 of an electric vehicle according to another embodiment of the present invention includes a pair of left and right front wheels on the front side as steering wheels, a pair of left and right rear wheels on the rear side as drive wheels, and a pair of A pair of left and right motors respectively provided corresponding to the rear wheels, a left rear wheel and a left motor 42a, and a pair of left and right drive shafts respectively connecting the right rear wheel and the right motor. Further, each case is constituted by a case having a predetermined volume, and lubricates from an oil tank 43a capable of storing therein lubricating oil for lubricating the motor 42a and a suction port provided at a lower portion of the oil tank 43a. An oil pump is provided that pumps up oil and supplies it to the motor 42a, and circulates lubricating oil inside the motor 42a. Here, the oil tank 43a is provided at the front side of the motor 42a at a position avoiding the lower region of the rotating shaft 44a of the motor 42a. You may comprise in this way.

  In the above embodiment, the position where the oil tank is provided is the rear side of the motor, or the front side, but not limited to this, the position where the oil tank is provided is It is good also as a structure including the area | region located in the vehicle width direction of a motor.

  FIG. 8 is a cross-sectional view showing a part of the drive unit 51 of the electric vehicle in this case. FIG. 8 corresponds to the cross section shown in FIG. Although illustration of some members of the drive unit 51 of the electric vehicle is omitted, the basic configuration is the same as the drive unit of the electric vehicle shown in FIG.

Referring to FIG. 8, a drive unit 51 of an electric vehicle according to still another embodiment of the present invention is provided with a pair of left and right front wheels provided on the front side of the vehicle body as steering wheels and on the rear side of the vehicle body as drive wheels. A pair of left and right rear wheels 52a and 52b, a pair of left and right motors 53a and 53b provided corresponding to the pair of rear wheels 52a and 52b, a left rear wheel 52a and a left motor 53a, and a right rear wheel, respectively. And a pair of left and right drive shafts 54a and 54b for connecting the motor 52b and the right motor 53b, respectively. Each of the oil tanks 55a and 55b is configured by a case having a predetermined volume and can store therein lubricating oil for lubricating the motors 53a and 53b, and each oil tank 55a. , 55b, and a pair of oil pumps for pumping the lubricating oil from suction ports provided in the lower part of 55b and supplying the lubricating oil to the respective motors 53a, 53b and circulating the lubricating oil into the respective motors 53a, 53b. The oil tank 55a is provided at the side of the motor 53a in the vehicle width direction at a position avoiding the lower region of the rotation shaft 56a of the motor 53a. Specifically, the oil tank 55a is provided at the side of the motor 53a on the side of the rear wheel 52a in the vehicle width direction at a position avoiding the lower region of the rotation shaft 56a of the motor 53a. That is, the oil tank 55a, to the motor 53a, is provided on the side of the direction opposite to the direction indicated by the arrow A ₂ shown in FIG. Similarly, the oil tank 55b is provided at the side of the motor 53b on the side of the rear wheel 52b in the vehicle width direction, avoiding the lower region of the rotation shaft 56b of the motor 53b. That is, the oil tank 55b, to the motor 53b, is provided on the side of the direction indicated by arrow _{A 2} shown in FIG. You may comprise in this way.

  Moreover, it is good also as a structure as shown in FIG. FIG. 9 is a cross-sectional view showing a part of a drive unit 61 of another electric vehicle in which the position where the oil tank is provided is a region located in the vehicle width direction of the motor. In addition, like the drive unit 51 of the electric vehicle shown in FIG. 8, illustration of some members of the drive unit 61 of the electric vehicle is omitted, but the basic configuration is the same as that of the electric vehicle shown in FIG. Same as drive unit.

Referring to FIG. 9, a drive unit 61 of an electric vehicle according to still another embodiment of the present invention is provided with a pair of left and right front wheels provided on the front side of the vehicle body as steering wheels and on the rear side of the vehicle body as drive wheels. A pair of left and right rear wheels 62a and 62b, a pair of left and right motors 63a and 63b provided corresponding to the pair of rear wheels 62a and 62b, a left rear wheel 62a and a left motor 63a, and a right rear wheel, respectively. 62b and a pair of left and right drive shafts 64a and 64b for connecting the right motor 63b and the right motor 63b, respectively. Each of the oil tanks 65a and 65b is configured by a case having a predetermined volume and can store therein lubricating oil for lubricating the motors 63a and 63b, and each oil tank 65a. , 65b, and a pair of oil pumps that draws lubricating oil from suction ports provided in the lower part of 65b, supplies the lubricating oil to the motors 63a, 63b, and circulates the lubricating oil in the motors 63a, 63b. The oil tank 65a is provided at the side of the motor 63a in the vehicle width direction at a position avoiding the lower region of the rotation shaft 66a of the motor 63a. Specifically, the oil tank 65a is provided at a position on the other side of the motor 63b in the vehicle width direction of the motor 63a at a position avoiding the lower region of the rotation shaft 66a of the motor 63a. That is, the oil tank 65a, to the motor 63a, is provided on the side of the direction indicated by arrow _{A 2} shown in FIG. Similarly, the oil tank 65b is provided at the other motor 63a side in the vehicle width direction of the motor 63b at a position avoiding the lower region of the rotation shaft 66b of the motor 63b. That is, the oil tank 65b, to the motor 63 b, is provided on the side of the direction opposite to the direction indicated by the arrow A ₂ shown in FIG. You may comprise in this way.

  In the above-described embodiment, the oil tank is provided on the same side of the pair of oil tanks at a position that avoids the lower region of the rotation shaft of the motor. It is not necessary to provide an oil tank on the same side for both of the pair of oil tanks. Furthermore, it is good also considering the location which provides an oil tank as two or more places. For example, the oil tank may be located at a position avoiding the lower region of the rotating shaft of the motor, and may be two places on the front side and the rear side of the motor, or other combinations shown in FIGS. Good. Furthermore, it may be the rear side in the diagonal direction of the motor or the front side in the diagonal direction.

  In the above embodiment, the driving wheel is the rear wheel and the steering wheel is the front wheel. However, the present invention is not limited thereto, and the driving wheel is the front wheel and the steering wheel is the rear wheel. Good. Alternatively, both the driving wheel and the steering wheel may be front wheels. In these cases, the motor is disposed on the front side of the vehicle body. Furthermore, all the wheels may be drive wheels.

  In addition, it is good also as a structure containing the reduction gear which decelerates rotation of a motor as a drive unit of an electric vehicle. In this case, you may comprise so that it may be provided between a motor and a wheel, for example. Examples of the speed reducer include a cycloid speed reducer and a planetary speed reducer. When the cycloid reducer is used, a high reduction ratio can be obtained, so that the motor can be reduced in size with respect to the torque required for the vehicle, and the weight of the drive unit of the electric vehicle can be reduced. In the case of a low-speed and lightweight vehicle that does not require a high reduction ratio, a planetary speed reducer may be used.

  Moreover, it is good also as a structure which attaches an under guard to the lower area | region of at least any one motor. By comprising in this way, a motor and an oil tank can be protected from the flying object from the road surface side.

  Although the embodiments of the present invention have been described with reference to the drawings, the present invention is not limited to the illustrated embodiments. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

  The drive unit for an electric vehicle according to the present invention is effectively used when low cost and long life are required while widening the vehicle body space.

  11, 31, 41, 51, 61 Electric vehicle drive unit, 12 chassis, 13a, 13b front wheel, 14a, 14b, 35a, 52a, 52b, 62a, 62b rear wheel, 15a, 15b, 32a, 42a, 53a, 53b , 63a, 63b Motor, 16a, 16b, 36a, 54a, 54b, 64a, 64b Drive shaft, 17a Central region, 17b End region, 18, 38a, 39a Axis, 19a, 19b, 40a, 44a, 56a, 56b , 66a, 66b Rotating shaft, 20a, 20b, 20c, 20d, 37a, 37b Constant velocity joint, 21a, 21b, 33a, 43a, 55a, 55b, 65a, 65b Oil tank, 22a, 22b Oil pump, 23a Lower region , 24 Road surface, 25a, 34a part, 26a Suction Mouth, 27a Bottom wall, 28a Top wall, 29a Lubricating oil, 30a Oil passage.

Claims (8)

A drive unit for an electric vehicle that drives wheels by rotation of a motor,
A pair of motors located in a central region in the vehicle width direction of at least one of the front side and the rear side of the vehicle body, each rotating shaft directing substantially in the vehicle width direction;
A pair of wheels disposed in an end region in the vehicle width direction and driven by rotation of each of the motors;
A pair of drive shafts extending along the axis of the rotating shaft and respectively connecting the motor and the wheels;
A pair of oil tanks each configured with a case having a predetermined volume and capable of storing therein lubricating oil for lubricating each of the motors;
A pair of oil pumps that draws lubricating oil from suction ports provided in the lower part of each of the oil tanks, supplies the lubricating oil to each of the motors, and circulates the lubricating oil inside each of the motors;
Each of the oil tanks is attached to the motor so as to be adjacent to the side of the motor in the vehicle width direction or the vehicle front-rear direction, and the position avoiding the lower region of the rotation shaft of the motor. A drive unit for an electric vehicle provided in the vehicle. The drive unit of the electric vehicle according to claim 1, wherein the position where each oil tank is provided includes a rear side of each motor. The drive unit of the electric vehicle according to claim 1 or 2, wherein a position where each of the oil tanks is provided includes a front side of each of the motors. The drive unit of the electric vehicle according to any one of claims 1 to 3, wherein a position where each of the oil tanks is provided includes a region located in a vehicle width direction of each of the motors. The vertical position of the vehicle body in which the suction port is provided is a region between a bottom wall located at the lowest part of the oil tank and 1/3 of the internal height of the oil tank. 4. The drive unit for an electric vehicle according to any one of 4 above. The electric motor drive unit according to claim 1, wherein the motor includes a speed reducer that decelerates rotation of the motor. The drive unit of the electric vehicle according to claim 6, wherein the position where the oil tank is provided includes a lower region of the speed reducer. The drive unit of the electric vehicle according to any one of claims 1 to 7, wherein an under guard is attached to a lower region of at least one of the motors.

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