JP5900012B2 - Powertrain structure for electric vehicles - Google Patents

Description

  The present invention relates to a power train structure for an electric vehicle in which an electric motor, an inverter, and a transmission are arranged between a pair of left and right drive wheels along an axle direction.

  2. Description of the Related Art Conventionally, a power train structure of an electric vehicle in which a power unit is miniaturized by arranging an electric motor, an inverter, and a transmission along the axle direction between a pair of left and right drive wheels is known (for example, Patent Document 1). reference).

JP 7-231672 A

However, the inverter needs to be electrically connected to the electric motor, and the transmission needs to be mechanically coupled to the output shaft of the electric motor. Therefore, in the conventional power train structure of an electric vehicle, an inverter is provided on one side of the electric motor, and a transmission is provided on the other side of the electric motor.
Thus, the shaft length of the output rotating shaft that protrudes from the side of the transmission that does not face the motor and connects to one drive wheel is the axis of the output rotating shaft that protrudes from the side of the transmission that faces the motor and connects to the other driving wheel. Shorter than the length. For this reason, the bending angle of the output rotating shaft protruding from the side surface of the transmission that does not face the electric motor is large.
Furthermore, if the shaft length of the output rotation shaft is increased, an increase in the bending angle of the output rotation shaft can be suppressed. However, in that case, there arises a problem that the vehicle width dimension increases.

  The present invention has been made paying attention to the above problems, and provides a power train structure for an electric vehicle that can increase the axial length of an output rotation shaft of a transmission while suppressing an increase in vehicle width dimension. With the goal.

In order to achieve the above object, in the powertrain structure for an electric vehicle according to the present invention, a pair of left and right drive wheels, an electric motor, an inverter that is electrically connected to the electric motor to perform rotation control, and converts the rotation of the electric motor. And a transmission for transmitting to the pair of left and right drive wheels via an output rotation shaft.
And when arrange | positioning the said electric motor, the said inverter, and the said transmission along an axle shaft between a pair of right-and-left drive wheels, the said transmission is arrange | positioned between the said electric motor and the said inverter.

In the powertrain structure for an electric vehicle according to the present invention, when the electric motor, the inverter, and the transmission are arranged along the axle between the pair of left and right drive wheels, the transmission is arranged between the electric motor and the inverter. The That is, an electric motor or an inverter is disposed between the transmission and the drive wheel.
As a result, if the position of the power unit consisting of the electric motor, inverter, and transmission is fixed between the pair of left and right drive wheels, the output rotation that protrudes from the side of the transmission is greater than when the transmission is disposed at the end of the unit. The shaft length of the shaft can be increased.
That is, when an inverter is provided on one side of the motor and a transmission is provided on the other side of the motor, the side of the transmission that does not face the motor serves as an end face of the power unit. Therefore, the axial length of the output rotation shaft protruding from the side surface of the transmission not facing the electric motor is equal to the dimension from the end surface of the power unit to one drive wheel.
On the other hand, in the power train structure of the present invention, the transmission is located in the middle part of the power unit including the electric motor, the inverter, and the transmission, and the side surface of the transmission is located inside the end face of the power unit. Therefore, the shaft length at the time of output rotation protruding from the side surface of the transmission is longer by the width dimension of the motor or the width dimension of the inverter than the dimension from the end face of the power unit to one drive wheel. Thereby, the axial length of an output rotating shaft can be lengthened, suppressing the increase in a vehicle width dimension, and the increase in the bending angle of an output rotating shaft can be suppressed.

It is a side view which shows the electric vehicle (an example of an electric vehicle) to which the powertrain structure of Example 1 was applied. It is a schematic diagram when the powertrain structure of Example 1 is seen from the vehicle front. 1 is an exploded perspective view showing a powertrain structure of Example 1. FIG. It is a schematic diagram when the powertrain structure of Example 1 is seen from the vehicle right side. It is a schematic diagram when the powertrain structure of Example 1 is seen from the vehicle upper side. It is a schematic diagram when the powertrain structure of a comparative example is seen from the vehicle front. In the power train structure of Example 1, it is a schematic diagram when it sees from the vehicle front which shows the time of a wheel moving up and down. It is a schematic diagram when the powertrain structure of Example 2 is seen from the vehicle front. It is explanatory drawing which shows the shaft structure of the reduction gear of Example 2. FIG. It is explanatory drawing which shows the shaft structure of the reduction gear of a comparative example. It is explanatory drawing which shows the unit height of a power train structure, (a) shows a comparative example, (b) shows Example 2. FIG.

  EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing the powertrain structure of the electric vehicle of this invention is demonstrated based on Example 1 and Example 2 which are shown in drawing.

First, the configuration will be described.
FIG. 1 is a side view showing an electric vehicle (an example of an electric vehicle) to which the powertrain structure of the first embodiment is applied. FIG. 2 is a schematic diagram when the powertrain structure of the first embodiment is viewed from the front of the vehicle. FIG. 3 is an exploded perspective view showing the powertrain structure of the first embodiment. FIG. 4 is a schematic diagram when the powertrain structure of the first embodiment is viewed from the right side of the vehicle. FIG. 5 is a schematic diagram of the powertrain structure according to the first embodiment when viewed from above the vehicle.

The electric vehicle S shown in FIG. 1 includes a power unit P that is a travel drive source, and a battery unit B that supplies power to the power unit P. Here, the power unit P is mounted in a motor room MR formed in the front portion of the vehicle body. The battery unit B has a nickel metal hydride battery or a lithium ion battery, and is mounted at the center position of the wheel base below the vehicle interior SR.
In FIG. 1, FL, (FR) are left and right front wheels, which are a pair of left and right drive wheels driven by the power unit P. RL, (RR) is the left and right rear wheels.

  The power unit P includes a motor / generator (electric motor) 1, an inverter 2, and a reduction gear (transmission) 3, and is disposed between the left and right front wheels FL and FR. The power unit P is connected to the left front wheel FL via a left drive shaft (output rotation shaft) LDS, and is connected to the right front wheel FR via a right drive shaft (output rotation shaft) RDS (see FIG. 2).

The motor / generator 1 is an AC motor that enables a three-phase synchronous motor or a three-phase induction motor and that can perform a power running operation during acceleration and a regenerative operation during deceleration. During power running, the left and right front wheels FL and FR are driven by receiving power from the battery unit B. Further, during the regenerative operation, the left and right front wheels FL and FR are rotated in the opposite direction to that during driving, and the battery unit B is charged.
As shown in FIG. 3, the motor / generator 1 includes a motor case 11, a stator (not shown) and a rotor (not shown) built in the motor case 11, and the motor case 11 outside the motor case 11. It has a plurality of coil windings (connection wires) 12 drawn out and a motor shaft (output shaft) 13 that rotates integrally with the rotor.

  The inverter 2 converts the direct current from the battery unit B into a three-phase alternating current during power running operation of the motor / generator 1 and supplies the three-phase alternating current to the motor / generator 1, and three-phase from the motor / generator 1 during regenerative operation. This is a power converter that converts an alternating current into a direct current and supplies it to the battery unit B. The inverter 2 is electrically connected to the motor / generator 1 via a coil winding 12, and is connected to an inverter case 21, an inverter circuit (not shown) built in the inverter case 21, and an inverter circuit. And a connector 22 to which the coil winding 12 is connected.

  The speed reducer 3 is a transmission that converts the output rotation of the motor / generator 1 (decelerates here) and transmits it to the left and right front wheels FL and FR via left and right drive shafts (output rotation shafts) LDS and RDS, respectively. . The speed reducer 3 includes a mission case 31, a drive gear 32, a driven gear 33, and a differential gear 34 (see FIG. 4).

The transmission case 31 is a hollow housing that incorporates the gears 32 to 34 and has a longer dimension in the vehicle front-rear direction than the motor case 11 and the inverter case 21. The inverter case 21 is mechanically fixed to the first side surface 31a of the transmission case 31 facing the left front wheel FL. The motor case 11 is mechanically fixed to the second side surface 31b of the transmission case 31 facing the right front wheel FR.
As shown in FIG. 5, the transmission case 31 includes a shaft insertion opening 31c, a left drive shaft protruding opening 31d, a right drive shaft protruding opening 31e, and a winding through hole (through hole) 31f (FIG. 3). Reference) is formed.
The shaft insertion opening 31c is an opening formed in the second side surface 31b and into which the motor shaft 13 is inserted.
The left drive shaft protruding opening 31d is formed in a portion not overlapping with the inverter case 21 of the first side surface 31a, here the rear portion, and is provided with a unit side constant velocity universal joint 35 to which one end of the left drive shaft LDS is connected. ing.
The right drive shaft protruding opening 31e is formed in a portion not overlapping with the motor case 11 on the second side surface 31b, here, in the rear portion, and provided with a unit side constant velocity universal joint 35 to which one end of the right drive shaft RDS is connected. ing.
The winding through-hole 31f is a through-hole through which a plurality of coil windings 12 that electrically connect the motor / generator 1 and the inverter 2 penetrate integrally. The winding through hole 31f is a portion overlapping the motor case 11 and the inverter case 21, and is formed at a position where it does not interfere with the built-in gears 32 to 34. Here, the coil winding 12 is pulled out from the motor case 11 and fixed in the inverter case 21. At this time, inside the winding through hole 31f, the plurality of coil windings 12 are sandwiched from above and below by the winding holder 31g and are prevented from contacting each other.

  The drive gear 32 is formed at the tip of the motor shaft 13 and rotates integrally with the motor shaft 13.

  The driven gear 33 is a gear that meshes with the drive gear 32. By this driven gear 33, the rotation of the motor / generator 1 is decelerated by one step.

The differential gear 34 is a differential gear that meshes with the driven gear 33 to further reduce the rotation of the motor / generator 1 and distribute this rotation to the left and right front wheels FL and FR. One end of each of the left and right drive shafts LDS and RDS is connected to the differential gear 34 via a unit-side constant velocity universal joint 35.
The left front shaft FLS is connected to the other end of the left drive shaft LDS via a wheel side constant velocity universal joint 36, and the other end of the right drive shaft RDS is connected to the right side via a wheel side constant velocity universal joint 36. Front wheel FR is connected.

Next, the operation will be described.
First, “the configuration and problems of the powertrain structure of the electric vehicle of the comparative example” will be described, and subsequently, the operation of the powertrain structure of the electric vehicle of the first embodiment will be described as “folding angle reducing action”, “coil winding arrangement”. The explanation will be divided into “strategic action” and “vehicle mountability improving action”.

[Configuration and Problems of Electric Vehicle Powertrain Structure of Comparative Example]
FIG. 6 is a schematic diagram when the powertrain structure of the comparative example is viewed from the front of the vehicle.

The power unit P1 of the comparative example shown in FIG. 6 is disposed between a pair of left and right drive wheels (here, left and right front wheels FL and FR), and is arranged along the axle direction (vehicle width direction) and an inverter 2A. And a reduction gear 3A.
In this power unit P1, the motor 1A is arranged in the center, the inverter 2A is provided on the right side (right front wheel FR side) of the motor 1A, and the speed reducer 3A is provided on the left side (left front wheel FL side) of the motor 1A. .

Here, the inverter 2A is a power converter that performs rotation control of the motor 1A, and is electrically connected to the motor 1A. The speed reducer 3A is a transmission that decelerates the output rotation of the motor 1A, and is mechanically connected to a motor shaft (not shown here) of the motor 1A.
That is, the motor 1A needs to be electrically or mechanically connected to each of the inverter 2A and the speed reducer 3A. On the other hand, it is not necessary to connect the inverter 2A and the speed reducer 3A, whether they are electrical or mechanical.

  For this reason, in the power unit P1 along the axle direction, it is most unavoidable to place the motor 1A in the center when viewed from the mutual connection relationship of the motor 1A, the inverter 2A, and the reduction gear 3A. Become advantageous.

However, at this time, in the power unit P1, the speed reducer 3A is located at the left end, that is, the leftmost front wheel FL side.
Therefore, for example, as shown in FIG. 6, when the power unit P1 is disposed in the center between the left and right front wheels FL, FR, that is, the distance L1 from the right unit end surface (side surface of the inverter 2A) to the right front wheel FR and the left unit. When the distance L2 from the end surface (side surface of the speed reducer 3A) to the left front wheel FL is made equal, the speed reducer 3A is closer to the left front wheel FL side than the center position O in the vehicle width direction of the power unit P1.

On the other hand, the left front wheel FL is connected to a differential gear (not shown here) built in the speed reducer 3A via a left drive shaft LDS ′ provided with constant velocity universal joints 37A at both ends. Further, the right front wheel FR is connected to a differential gear (not shown here) built in the speed reducer 3A via a right drive shaft RDS ′ provided with constant velocity universal joints 37B at both ends.
At this time, the speed reducer 3A is closer to the left front wheel FL side, so the left drive shaft LDS 'is shorter than the right drive shaft RDS'.

As a result, the bending angle θ1 of the left drive shaft LDS ′ (the tilt angle of the drive shaft with respect to the horizontal position with respect to the end on the speed reducer 3A side) is relatively large. When the bending angle θ1 is large, a large load acts on the constant velocity universal joint 37A, and there is a possibility that the durability of the constant velocity universal joint 37A is reduced.
Further, even when the left and right front wheels FL and FR move up and down (bound), the left drive shaft LDS ′ is short, so that the bending angle increases and the load on the constant velocity universal joint 37A increases.
If the bending angle θ1 is too large, the constant velocity universal joint 37A cannot be provided. In this case, it is necessary to separate the left front wheel FL from the power unit P1, which causes a new problem that the vehicle width dimension increases.

  Further, since the shaft length of the right drive shaft RDS ′ is relatively long, the shaft is liable to bend and distort, and an intermediate bearing has to be provided as necessary.

  Furthermore, if there is too much difference between the bending angles and lengths of the left and right drive shafts LDS´, RDS´, the left / right difference in drive torque between the left and right front wheels FL, FR will increase and torque steer will occur, impairing steering stability. There was also a risk of being lost.

[Bending angle reduction effect]
FIG. 7 is a schematic diagram of the powertrain structure according to the first embodiment when viewed from the front of the vehicle, showing when the wheels move up and down.

  In the powertrain structure of the electric vehicle according to the first embodiment, the speed reducer 3 is disposed between the motor / generator 1 and the inverter 2. That is, in the power unit P, the speed reducer 3 is disposed at the center position.

For this reason, as shown in FIG. 7, when the power unit P is disposed in the center between the left and right front wheels FL, FR, the speed reducer 3 is disposed at substantially the same position as the center position O in the vehicle width direction.
Thus, the distance L3 from the left unit end surface (side surface of the inverter 2) to the left front wheel FL is equal to the distance L2 from the left unit end surface (side surface of the speed reducer 3A) to the left front wheel FL in FIG. However, the shaft length of the left drive shaft LDS of the first embodiment can be made longer than that of the left drive shaft LDS ′ of the comparative example.
That is, a longer shaft length of the left drive shaft LDS can be ensured than in the comparative example without increasing the vehicle width dimension.

Therefore, the bending angle θ2 in the left drive shaft LDS of the first embodiment is smaller than the respective bending θ1 in the comparative example. As a result, it is possible to prevent a large load from being applied to the unit side constant velocity universal joint 35 and the wheel side constant velocity universal joint 36 provided at both ends of the left drive shaft LDS, and the durability of the universal joints 35 and 36 is impaired. Can be prevented.
Further, even when the left and right front wheels FL, FR move up and down (bound), if the left drive shaft LDS is lengthened, the bending angle becomes small, and the load acting on the universal joints 35, 36 can be suppressed.

    Further, by reducing the bending angle θ2, the load acting on the left drive shaft LDS can be reduced as compared with the comparative example, and the life of the left drive shaft LDS can be increased. Further, since the shaft load is reduced, high durability is not required, and the left drive shaft LDS can be downsized and an inexpensive drive shaft can be applied.

  On the other hand, the right drive shaft RDS of the first embodiment can be made shorter than the right drive shaft RDS ′ of the comparative example. Therefore, it is possible to prevent the shaft from being bent or distorted and to eliminate the need for an intermediate bearing.

  Furthermore, if the axial lengths of the left and right drive shafts LDS and RDS are balanced and the difference between the left and right bending angles is reduced, the left and right difference in drive torque between the left and right front wheels FL and FR is also reduced. As a result, torque steer is less likely to occur, and steering stability can be improved.

[Coil winding arrangement action]
In the power train structure of the electric vehicle according to the first embodiment, a winding through hole 31f through which the coil winding 12 drawn from the motor / generator 1 passes is formed in the transmission case 31 of the speed reducer 3.
Here, the winding through-hole 31f is a portion overlapping the motor case 11 and the inverter case 21, and is formed at a position where it does not interfere with the built-in gears 32 to 34. That is, the winding through hole 31 f is located inside the motor case 11 and the inverter case 21 fixed to the transmission case 31.

Therefore, the coil winding 12 is routed in a sealed space surrounded by the motor case 11, the inverter case 21, and the transmission case 31, and the coil winding 12 is coiled from foreign matters such as water, mud, and dust entering from the outside of the vehicle. The winding 12 can be protected. The coil winding 12 does not need to be covered with a covering material or the like, and can be manufactured at a low cost.
Further, since the winding holder 31g is also disposed in the winding through hole 31f, a simple structure can be obtained.

[Vehicle mountability improvement effect]
In the powertrain structure of the electric vehicle according to the first embodiment, as shown in FIG. 5, the motor / generator 1, the inverter 2, and the speed reducer 3 are arranged in a line along the axle direction (vehicle width direction). Yes.

For this reason, since the motor / generator 1 and the like do not overlap in the height direction (the vehicle vertical direction), the protrusion in the height direction can be suppressed, and a so-called short power unit P can be obtained.
Thereby, the mounting space at the time of mounting in the electric vehicle S can be made small, and it can be excellent in vehicle mounting property.

  In general, side members (not shown), so-called undercarriage parts (not shown) such as a wheel housing and a suspension mechanism are arranged on both sides of the motor room MR (shown by A in FIG. 5). Is done. Further, the motor room MR and the vehicle compartment SR are partitioned by a dash panel D. The region closer to the motor room MR than the dash panel D (region indicated by B in FIG. 5) relates to steering (not shown). Parts are placed.

On the other hand, in Example 1, the dimension of the transmission case 31 of the reduction gear 3 arranged in the center of the power unit P in the longitudinal direction of the vehicle is longer than that of the motor case 11 and the inverter case 21 as shown in FIG. Here, it protrudes backward.
That is, in this power unit P, the center part of the unit is protruded rearward, and an increase in the vehicle longitudinal dimension is suppressed on both sides of the unit.

  As a result, the power unit P of the first embodiment is divided into both sides of the motor room MR (region shown by A in FIG. 5) and the region closer to the motor room MR than the dash panel D (region shown by B in FIG. 5). The unit shape can be made to match the motor room MR where the installation space for the power unit P cannot be provided. Therefore, it becomes easy to perform the layout to the motor room MR, and the vehicle mounting performance of the power unit P can be further improved.

Next, the effect will be described.
In the powertrain structure of the electric vehicle according to the first embodiment, the following effects can be obtained.

(1) Between a pair of left and right drive wheels (left and right front wheels) FL and FR, an electric motor (motor / generator) 1, an inverter 2 electrically connected to the electric motor 1 to perform rotation control, and the electric motor 1 In a powertrain structure of an electric vehicle in which a transmission (reduction gear) 3 that converts rotation and transmits the rotation to each of the pair of left and right drive wheels FL and FR is disposed along an axle,
The transmission 3 is arranged between the electric motor 1 and the inverter 2.
Thereby, the axial length of the output rotation shaft (left drive shaft) LDS of the transmission (reduction gear) 3 can be increased while suppressing an increase in the vehicle width dimension.

(2) The transmission (reduction gear) 3 includes a through hole (winding through hole) through which a connection wire (coil winding) 12 that electrically connects the electric motor (motor / generator) 1 and the inverter 2 passes. It was set as the structure which has 31f.
Thereby, the protection performance of the connection wire (coil winding) 12 from a foreign material can be improved with an inexpensive structure.

  The power train structure of the electric vehicle according to the second embodiment is an example in which a so-called parallel two-shaft transmission is applied.

FIG. 8 is a schematic diagram of the powertrain structure according to the second embodiment when viewed from the front of the vehicle. FIG. 9 is an explanatory diagram showing the motor shaft and the left and right drive shafts of the powertrain structure of the second embodiment.
In addition, about the structure equivalent to Example 1, the same code | symbol as Example 1 is used and detailed description is abbreviate | omitted.

  Also in the power unit P2 of the second embodiment, the reduction gear 3B is arranged in the center of the unit, the motor / generator 1B is provided on the right front wheel FR side of the reduction gear 3B, and the inverter 2B is provided on the left front wheel FL side of the reduction gear 3B. Then, a differential gear (see FIG. 9) 34B built in the speed reducer 3B and the left front wheel FL are connected via a left drive shaft LDS provided with constant velocity universal joints 38A at both ends, and this differential gear 34B is connected to the differential gear 34B. The right front wheel FR is connected via a right drive shaft RDS provided with constant velocity universal joints 38B at both ends.

As shown in FIG. 9, the speed reducer 3B according to the second embodiment includes a drive gear (motor output gear) 32B and a differential gear (transmission gear) 34B.
The drive gear 32B is formed at the tip of the motor shaft 13 of the motor / generator 1B and rotates integrally with the motor shaft 13.
The differential gear 34B meshes with the drive gear 32B, decelerates the rotation of the motor / generator 1B, and is connected to the left and right drive shafts LDS and RDS, respectively, and distributes the rotation from the drive gear 32B to the left and right, and the left and right front wheels FL and FR It becomes the differential device which transmits to.
That is, the speed reducer 3B is a parallel biaxial transmission in which the motor shaft 13 as an input shaft and the left and right drive shafts LDS and RDS as output shafts are arranged in parallel.

  Thus, like the reduction gear 3A of the comparative example shown in FIG. 10, the drive gear 40 provided on the motor shaft 13A of the motor 1A, the driven gear 41 that meshes with the drive gear 40, and the differential gear 42 that meshes with the driven gear 41. As compared with the case where the gear ratio is the same, the reduction gear 3B of the second embodiment can increase the differential gear diameter R even with the same gear conversion ratio.

Therefore, as shown in FIG. 11, if the minimum ground height H in each of the power unit P1 of the comparative example and the power unit P2 of the second embodiment is the same, the shaft of the speed reducer 3B is higher than the shaft height OH1 of the speed reducer 3A. Height OH2 is higher.
For this reason, the distance from the road surface G to the motor / generator 1B and the inverter 2B is higher in the second embodiment than in the comparative example, and is less susceptible to the impact from the road surface G, the influence of the stone, etc. Can do.

  In the case of the second embodiment, the reduction gear 3B is arranged at the center of the unit, so that the distance L4 from the left front wheel FL to the reduction gear 3B is the distance L2 from the left front wheel FL to the reduction gear 3A in the comparative example. Can be longer. For this reason, the left drive shaft of the second embodiment is made the same as the folding angle θ1 of the left drive shaft LDS ′ in the power unit P1 of the comparative example and the folding angle θ3 of the left drive shaft LDS in the power unit P2 of the second embodiment. LDS can be made longer.

  Furthermore, the reduction gear 3B does not require a driven gear between the drive gear 32B and the differential gear 34B, and therefore can be made inexpensive.

  Therefore, in the powertrain structure of the electric vehicle according to the second embodiment, the following effects can be obtained.

(3) Output rotation shafts (left and right drive shafts) LDS, RDS of the transmission (reduction gear 3B) are motor output gears (drive gears) formed on the output shaft (motor shaft) 13 of the motor (motor / generator) 1B. ) It has a structure having a transmission gear (differential gear) 34B meshing with 32B.
As a result, the shaft height OH2 of the speed reducer 3B can be increased so that the motor / generator 1B and the inverter 2B are less susceptible to the impact from the road surface G and the influence of the stone. 3B can be applied.

  As mentioned above, although the powertrain structure of the electric vehicle of this invention has been demonstrated based on Example 1 and Example 2, it is not restricted to these Examples about a concrete structure, Each of Claims Design changes and additions are permitted without departing from the scope of the claimed invention.

  In each of the above-described embodiments, an example in which a speed reducer that decelerates motor rotation is applied as a transmission is shown, but the present invention is not limited thereto. For example, a transmission capable of switching between a speed reduction stage and a constant speed stage using a clutch or the like, or a continuously variable transmission can be applied.

  Moreover, although the example which applied the motor / generator which can perform power running operation and regenerative operation as an electric motor was shown, the motor which performs only power running operation may be sufficient, and the generator which performs only regenerative operation may be sufficient.

Further, in the first embodiment, the power unit P is disposed in the motor room MR formed in the front portion of the vehicle, and the so-called front wheel drive vehicle that drives the left and right front wheels FL and FR is used. The power unit to which the power train structure of the present invention is applied is arranged at the rear of the vehicle, and the left and right rear wheels RL, RR may be used as driving wheels, the power unit is arranged at the front and rear of the vehicle, and all the wheels FL, FR, RL, RR may be used as a drive wheel.
Even if the power unit to which the power train structure of the present invention is applied is arranged in either the front part of the vehicle or the rear part of the vehicle, it is excellent in vehicle mountability. A wide space can be secured.

  And in Example 1, although the example which applied this invention to the electric vehicle S which has only the motor / generator 1 as a traveling drive source was shown, it is not restricted to this, The hybrid vehicle which uses an engine together as a traveling drive source, The fuel cell vehicle etc. which applied the fuel cell to the motor power supply may be sufficient. That is, the present invention can be applied to any electric vehicle in which an electric motor, an inverter, and a transmission are arranged side by side in the axle direction.

S Electric car (electric vehicle)
P Power unit B Battery unit 1 Motor / generator (electric motor)
11 Motor case 12 Coil winding 13 Motor shaft (output shaft)
2 Inverter 21 Inverter case 3 Reducer (transmission)
31 Mission case 31f Winding through hole (through hole)
32 drive gear 33 driven gear 34 differential gear 35 unit side constant velocity universal joint 36 wheel side constant velocity universal joint

Claims (2)

Between the pair of left and right drive wheels, an electric motor, an inverter that is electrically connected to the motor to perform rotation control, and the pair of left and right drive wheels via an output rotation shaft by converting the rotation of the motor, respectively. In the powertrain structure of an electric vehicle in which the transmission for transmission is arranged along the axle,
The transmission, the electric motor and the inverter constitute a power unit,
The transmission is integrally disposed between the electric motor and the inverter, and the electric motor and the inverter are electrically connected to a portion where the electric motor and the inverter overlap with the transmission interposed therebetween. A through-hole through which the connecting line to penetrate is formed,
The power train structure for an electric vehicle, wherein the connection line passing through the through hole is routed in a space surrounded by a case of the power unit . In the powertrain structure of the electric vehicle according to claim 1 ,
The output rotation shaft of the transmission has a transmission gear that meshes with an electric motor output gear that rotates integrally with the output shaft of the electric motor.