JP2017203503A - Vehicle drive unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle drive unit which suppresses the elongation of the vehicle drive unit in an axial direction, and can narrow a mounting space in a vehicle width direction.SOLUTION: A vehicle drive unit comprises two electric motors 2L, 2R, a gear device 30 for distributing torque from the electric motors 2L, 2R to left and right wheels, and a reduction gear for transmitting the torque of the electric motors 2L, 2R to drive wheels. The gear device 30 is composed of two pieces of three-element two-freedom planetary gear mechanisms which are obtained by being coaxially combined with a pair of left and right intermediate gear shafts 13L, 13R having input-side outer gears 13a. An idler gear 70a is arranged between an input gear 12a and the input-side outer gears 13a of the intermediate gear shafts 13L, 13R to which torque from the input gear 12a is transmitted, and a diameter of the idler gear 70a is regulated so that a distance from centers of motor shafts 5a of the electric motors 2L, 2R up to the gear device 30 is set longer than a distance from the centers of the motor shafts 5a of the electric motors 2L, 2R up to an end part of a stator 6 of the electric motors 2L, 2R in a radial direction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle drive device capable of amplifying a torque difference and transmitting drive torque from two independent drive sources to left and right drive wheels.

  In vehicles such as electric vehicles, electric motors are arranged on the left and right drive wheels, respectively, and each electric motor is controlled independently to give an appropriate drive torque difference between the left and right drive wheels. It is known to control. For example, when each electric motor is independently connected to the left and right drive wheels via a reduction gear, the rotational speed of each electric motor is reduced by the respective reduction gear, and the output torque of each electric motor is It is increased by each reducer and transmitted to the left and right drive wheels. Here, in order to make the vehicle turn right and turn left in the same manner, each electric motor has the same output characteristics, and each reduction gear has the same reduction ratio.

  By the way, when it is desired to make a difference between the output torques of the left and right drive wheels, a difference is made between the output torques of the left and right electric motors, and the output torques of the left and right electric motors are transmitted to the left and right drive wheels via a reduction gear.

  The output torques of the left and right electric motors transmitted to the left and right drive wheels are increased according to the reduction ratio of the speed reducer. However, the ratio of the difference between the output torques of the left and right drive wheels is the same as the ratio of the difference between the output torques of the left and right electric motors because the reduction ratio of the left and right reduction gears is the same. The ratio of the torque difference is not increased.

  However, in order to achieve smooth turning of the vehicle and to suppress changes in vehicle behavior such as extreme understeer and extreme oversteer, the left and right drive is more than the ratio of the difference in output torque applied from the left and right electric motors. It may be effective to increase the ratio of the difference in output torque transmitted to the wheels.

  Patent Document 1 and Patent Document 2 include a gear device in which two planetary gear mechanisms having three elements and two degrees of freedom are coaxially arranged between two drive sources and left and right drive wheels. A vehicle drive device is disclosed that can amplify the difference between torques applied to the left and right driving wheels and amplify the difference.

  A vehicle driving device disclosed in Patent Document 1 (hereinafter referred to as Conventional Technology 1) will be described with reference to FIGS. 15 and 16. FIG. 15 is a skeleton diagram showing the gear configuration of the vehicle drive device according to the prior art 1. FIG. 16 is a speed line for explaining the amplification factor of the torque difference by the gear device incorporated in the vehicle drive device according to the prior art 1. FIG.

  As shown in FIG. 15, the vehicle drive device 100 includes left and right electric motors 102L and 102R mounted on the vehicle, left drive wheels 104L and right drive wheels 104R, a gear device 105 provided therebetween, and a reduction gear. Gear trains 106L and 106R are provided.

  The electric motor 102L and the electric motor 102R operate with electric power from a battery (not shown) mounted on the vehicle, are individually controlled by an electronic control device (not shown), and can generate and output different torques. .

  The input gear shaft 102aL of the electric motor 102L and the input gear shaft 102aR of the electric motor 102R are connected to the coupling members 112 and 111 of the gear device 105 through reduction gear trains 106L and 106R, respectively. The output from the gear unit 105 is given to the left and right drive wheels 104L, 104R.

  The gear device 105 is configured by combining two identical planetary gear mechanisms 110L and 110R having three elements and two degrees of freedom on the same axis.

As the planetary gear mechanisms 110L and 110R, for example, a double pinion planetary gear mechanism having two planetary gears is employed. The planetary gear mechanism is coaxially provided between the sun gears S _L and S _R and the internal gears R _L and R _R provided on the same axis, and between the sun gears S _L and S _R and the internal gears R _L and R _R. The planetary carriers C _L and C _R provided above and a plurality of planetary gears P _L and P _R that are rotatably supported by the planet carriers C _L and C _R and mesh with each other. Here, the sun gears S _L and S _R and the planetary gears P _L and P _R are external gears having gear teeth on the outer periphery, and the internal gears R _L and R _R are internal gears having gear teeth on the inner periphery.

In the two planetary gears P _L and P _{R, one} of the two gears meshes with the sun gears S _L and S _R, and the other of the two gears meshes with the internal gears R _L and R _R. In the double pinion planetary gear mechanism as shown in FIG. 15, when the planetary carriers C _L and C _R are fixed, the sun gears S _L and S _R and the internal gears R _L and R _R rotate in the same direction. In the velocity diagram shown in FIG. 16, the internal gears R _L and R _R and the sun gears S _L and S _R are arranged on the same side with respect to the planetary carriers C _L and C _R. In other words, the planet carrier C _L, C _R is the internal gear R _L, sun gear across the R _R S _L, located on the opposite side of the S _R, the internal gear R _L, when fixing the R _R is the sun The gears S _L and S _R and the planet carriers C _L and C _R rotate in the opposite directions.

In the velocity diagram shown in FIG. 16, the ratio of the length from the planet carriers C _L and C _R to the internal gears R _L and R _R and the length from the planet carriers C _L and C _R to the sun gears S _L and S _R Is equal to the ratio of the reciprocal number (1 / Zr) of the number of teeth Zr of the internal gears R _L and R _R and the reciprocal number (1 / Zs) of the number of teeth Zs of the sun gears S _L and S _R.

As shown in FIG. 15, this gear device 105 includes a first planetary gear mechanism 110L having a sun gear S _L , a planetary carrier C _L , a planetary gear P _L and an internal gear _RL , as well as a sun gear S _R and a planet carrier. C _R, and a second planetary gear mechanism 110R having a planetary gear P _R and the internal gear R _R is configured by combining coaxially.

And, the sun gear S _L of the first planetary gear mechanism 110L and planet carrier C _R of the second planetary gear mechanism 110R is coupled with the first coupling member 111, and planet carrier C _L of the first planetary gear mechanism 110L second The sun gear S _R of the planetary gear mechanism 110R is coupled by the second coupling member 112.

As shown in FIG. 15, the torque TM1 generated by the first electric motor 102R is input to the first coupling member 111 via the reduction gear train 106R, and the second electric motor 102L is input to the second coupling member 112. The torque TM2 generated in the above is input through the reduction gear train 106L. Further, the internal gear R _L of the first planetary gear mechanism 110L is connected to the left driving wheel 104L via the output shaft 114, the internal gear R _R of the second planetary gear mechanism 110R right driving wheel 104R via the output shaft 113 Connected to.

  Here, the drive torque transmitted by the gear device 105 will be described with reference to a velocity diagram shown in FIG. Since the gear device 105 is configured by combining two identical planetary gear mechanisms 110L and 110R, it can be represented by two velocity diagrams as shown in FIG. Here, for easy understanding, the two velocity diagrams are shifted up and down, the velocity diagram of the first planetary gear mechanism 110L is shown on the upper side, and the velocity diagram of the second planetary gear mechanism 110R is shown on the lower side.

Further, in the velocity diagram of the first planetary gear mechanism 110L and the velocity diagram of the second planetary gear mechanism 110R, the sun gears S _L , S _R and the planet carriers C _L , C _R are arranged opposite to each other in the left-right direction. That is, in FIG. 16, the planet carrier C _R of the second planetary gear mechanism 110R is arranged on the sun gear S _L of the first planetary gear mechanism 110L, a below the planet carrier C _L of the first planetary gear mechanism 110L the sun gear S _R of second planetary gear mechanism 110R is disposed.

In the gear device 105, the elements located at both ends of the two velocity diagrams shown in FIG. 16 are connected to each other as shown by the broken lines in the drawing to form the first connecting member 111 and the second connecting member 112. The The torque TM1 output from the first electric motor 102R is applied to the first coupling member 111 via the reduction gear train 106R. This first coupling member 111 connected to the sun gear S _L, so that the part of the torque TM1 output from the first electric motor 102R is provided through a reduction gear train 106R. The remainder of the torque TM1 output from the first electric motor 102R is provided to the planet carrier C _R through the reduction gear train 106R.

Torque TM2 output from the second electric motor 102L is input to the second coupling member 112 via the reduction gear train 106L. This second coupling member 112 connected to the sun gear S _R, so that the part of the torque TM2 output from the second electric motor 102L is provided through a reduction gear train 106L. The remainder of the torque TM2 output from the second electric motor 102L is provided in the planet carrier C _L via a reduction gear train 106L. Here, originally, the torques TM1 and TM2 output from the electric motors 102R and 102L are input to the coupling members 111 and 112 via the reduction gear trains 106R and 106L, respectively. For the sake of simplicity, the reduction ratio is omitted in the speed diagram and the explanation of each calculation formula, and the torques input to the coupling members 111 and 112 remain TM1 and TM2.

On the other hand, the drive torques TL and TR transmitted from the internal gears R _L and R _R located in the middle of the speed diagram to the left and right drive wheels 104L and 104R are output.

  The gear device 105 configured as described above gives a torque difference (input torque difference) ΔTIN (= TM2−TM1) to each motor torque TM1 and TM2 generated by the first electric motor 102R and the second electric motor 102L. A drive torque difference ΔTOUT (= TL−TR) can be generated between the drive torque TL transmitted to the left drive wheel 104L and the drive torque TR transmitted to the right drive wheel 104R. That is, according to the gear device 105, the relationship of the following expression (1) is obtained. The coefficient α is a torque difference amplification factor.

  (TL-TR) = α × (TM2-TM1) (1)

The torque difference amplification factor α of the gear device 105 according to prior art 1 will be described. Here, two double-pinion planetary gear mechanism 110L, 110R is due to the use of gear elements of the same number of teeth, in the velocity diagram, the distance and the internal gear of the internal gear R _L and the planet carrier C _L The distance between R _R and the planet carrier C _R is equal, and this is a. Further, the distance between the sun gear S _L and the internal gear R _L and the distance between the sun gear S _R and the internal gear R _R are also equal, which is b.

Torques TM1 and TM2 of the first electric motor 102R and the second electric motor 102L are input to the first coupling member 111 and the second coupling member 112 at the left and right ends, respectively, and the driving torques TL and TR are transmitted from the internal gears R _L and R _R. Take out.

From the relationship between torque input and output, the following equation (2) is obtained.
TR + TL = TM1 + TM2 (2)

Further, expression of the left end (C _L, S _R portion) moment relative to the in the figure become the following equation (3). In the figure, the arrow direction indicates the positive direction of the moment M.

  0 = aTL + bTR− (a + b) TM1 (3)

  Summarizing TL and TR from these equations (2) and (3), the following equations (4) and (5) are obtained.

TL = ((a / (ba)) + 1) .TM2- (a / (ba)). TM1 (4)
TR = ((a / (ba)) + 1) .TM1- (a / (ba)). TM2 (5)

  From these equations (4) and (5), the drive torque difference (TL-TR) is the following equation (6).

(TL-TR) = ((a + b) / (ba)). (TM2-TM1) (6)

  In the case of the double pinion planetary gear mechanism, the length a is the reciprocal (1 / Zr) of the number of teeth Zr of the internal gear R, and the length a + b is the reciprocal (1 / Zs) of the number of teeth Zs of the sun gear S. Is rewritten as equation (7).

  (TL-TR) = (Zr / (Zr-2Zs)). (TM2-TM1) (7)

  From the above equations (1) and (7), the torque difference amplification factor α is Zr / (Zr−2Zs).

As described above, in the prior art 1, the inputs from the first and second electric motors 102L and 102R are the sun gear S _R and the planet carrier C _L , the sun gear S _L and the planet carrier C _R , and the driving wheel 104L , 104R are the internal gears R _L , R _R.

  When different torques TM1 and TM2 are generated by the two electric motors 102R and 102L to give an input torque difference ΔTIN (= TM2−TM1), the gear device 105 amplifies the input torque difference ΔTIN and is larger than the input torque difference ΔTIN. A drive torque difference α · ΔTIN can be obtained. That is, even if the input torque difference ΔTIN is small, the gear device 105 can amplify the input torque difference ΔTIN with a predetermined torque difference amplification factor α, and the drive torque transmitted to the left drive wheel 104L and the right drive wheel 104R. A driving torque difference ΔTOUT (= α · (TM2−TM1) = TL−TR) larger than the input torque difference ΔTIN can be given to TL and TR.

  Next, a vehicle drive device disclosed in Patent Document 2 (hereinafter referred to as Conventional Technology 2) will be described with reference to FIGS. 17 and 18. FIG. 17 is a skeleton diagram showing the gear configuration of the vehicle drive device according to the conventional technique 2, and FIG. 18 is a velocity diagram for explaining the torque difference amplification factor by the vehicle drive apparatus according to the conventional technique 2.

  In FIG. 17, in order to make the difference from the prior art 1 easier to understand, the electric motors 102L and 102R are arranged on the left and right sides so as to be the same as in the prior art 1, and the same components are denoted by the same reference numerals. ing.

  As shown in FIG. 17, the vehicle drive device 100 includes an electric motor 102L and an electric motor 102R mounted on the vehicle, a left drive wheel 104L and a right drive wheel 104R, a gear device 105 provided between them, and a reduction gear. Columns 106L and 106R are provided.

The electric motor 102L and the electric motor 102R operate with electric power from a battery (not shown) mounted on the vehicle, are individually controlled by an electronic control device (not shown), and can generate and output different torques. . The input gear shaft 102aL of the electric motor 102L and the input gear shaft 102aR of the electric motor 102R are connected to the sun gears S _L and S _R of the gear device 105 through reduction gear trains 106L and 106R, respectively. The output from the gear unit 105 is given to the left and right drive wheels 104L, 104R.

  Like the prior art 1, the gear device 105 of the prior art 2 is configured by combining two identical planetary gear mechanisms 110L and 110R having three elements and two degrees of freedom on the same axis. As the planetary gear mechanisms 110L and 110R, for example, single-pinion type planetary gear mechanisms are employed.

Then, the planet carrier C _L of the first planetary gear mechanism 110L and the internal gear R _R of the second planetary gear mechanism 110R is coupled by a first coupling member 111, and the internal gear R _L of the first planetary gear mechanism 110L second a planet carrier C _R of the planetary gear mechanism 110R is coupled by the second coupling member 112.

Torque TM1 generated by the electric motor 102L is input to the sun gear S _L of the first planetary gear mechanism 110L via a reduction gear train 106L, torque TM2, which is generated by the electric motor 102R is first through the reduction gear train 106R is input to the sun gear S _R of second planetary gear mechanism 110R.

  The first coupling member 111 and the second coupling member 112 are connected to the left and right drive wheels 104L and 104R, respectively, and output is taken out.

In this prior art 2, the inputs from the electric motors 102L and 102R are the sun gears S _L and S _R , and the outputs to the drive wheels 104L and 104R are the planet carrier C _L , the internal gear R _R and the planet carrier C _R. It becomes an internal gear R _L.

  Here, the driving torque transmitted by the gear device 105 of the prior art 2 will be described with reference to a velocity diagram shown in FIG.

Since the gear device 105 shown in FIG. 17 is configured by combining two identical single pinion planetary gear mechanisms 110L and 110R, it can be represented by two velocity diagrams as shown in FIG. Here, for ease of understanding, the two speed diagrams are shifted up and down, the speed diagram of the first planetary gear mechanism 110L is shown on the upper side, and the speed diagram of the second planetary gear mechanism 110R is shown on the lower side. Is shown. Similarly to the description in the related art 1, in the following explanation of the velocity diagram and each calculation formula, the reduction ratio in each reduction gear train 106L, 106R is omitted, and each sun gear S _L , S _R is assigned to each sun gear S _L , S _R. The input torque remains TM1 and TM2.

In the gear device 105 shown in FIG. 17, the planet carrier C _L and the internal gear R _R, as shown by broken line in the drawing of FIG. 18, are coupled by a first coupling member 111, the planet carrier C _R and the internal gear R _L is These are coupled by the second coupling member 112 as indicated by a broken line in the figure.

Then, torques TM1 and TM2 output from the first electric motor 102L and the second electric motor 102R are input to the sun gears S _L and S _R , respectively. On the other hand, the drive torques TL and TR transmitted from the first coupling member 111 and the second coupling member 112 located in the middle of the velocity diagram to the left and right driving wheels 104L and 104R are output.

  The gear device 105 configured in this manner also gives a torque difference (input torque difference) ΔTIN (= TM2−TM1) to the motor torques TM1 and TM2 generated by the first electric motor 102L and the second electric motor 102R. Thus, a drive torque difference ΔTOUT (= TR−TL) can be generated between the drive torque TL transmitted to the left drive wheel 104L and the drive torque TR transmitted to the right drive wheel 104R.

The torque difference amplification factor α of the gear device 105 according to prior art 2 will be described. Also in this prior art 2, since the two single pinion type planetary gear mechanisms 110L and 110R use gear elements having the same number of teeth, the internal gear R _L and the planet carrier C _L And the distance between the internal gear R _R and the planetary carrier C _R are equal to each other. Further, the distance between the sun gear S _L and the planet carrier C _L and the distance between the sun gear S _R and the planet carrier C _R are also equal, which is b. The ratio of the length from the planet carrier C _L , C _R to the internal gear R _L , R _R and the length from the planet carrier C _L , C _R to the sun gear S _L , S _R is the ratio of the internal gear R _L , R _R It is equal to the ratio of the reciprocal number (1 / Zr) of the number of teeth Zr and the reciprocal number (1 / Zs) of the number of teeth Zs of the sun gears S _L and S _R. Therefore, a = (1 / Zr) and b = (1 / Zs).

  FIG. 18 shows the gear device 105 of the prior art 2 as a velocity diagram.

  In this speed diagram, when considering the balance of torque, the torque difference gain α can be obtained. In the figure, the arrow direction indicates the positive direction of the moment M.

The following equation (8) is calculated from the balance of the moment M with respect to the point of S _R.
b.TR + (a + b) .TL- (a + 2b) .TM1 = 0 (8)

The following equation (9) is calculated from the balance of the moment M with respect to the point of S _L.
-B.TL- (a + b) .TR + (a + 2b) .TM2 = 0 (9)

The following expression (10) is calculated from the expression (8) + the expression (9).
a. (TR-TL)-(a + 2b). (TM2-TM1) = 0
(TR-TL) = ((a + 2b) / a). (TM2-TM1) (10)

  (A + 2b) / a in the equation (10) is the torque difference amplification factor α.

  When a = 1 / Zr and b = 1 / Zs are substituted, α = (2Zr + Zs) / Zs.

In the prior art 2, the electric motor 102L, input from 102R is the sun gear S _L, S _R, driving wheels 104L, output planet carrier C _L and an internal gear R _R to 104R, the planet carrier C _R and the internal gear R _L , and the torque difference amplification factor α is (2Zr + Zs) / Zs.

  As described above, in the conventional technology 1 and the conventional technology 2, when the two electric motors 102L and 102R generate different torques TM1 and TM2 to give the input torque difference ΔTIN, the gear device 105 receives the input torque. The difference ΔTIN is amplified, and a driving torque difference ΔTOUT larger than the input torque difference ΔTIN can be obtained.

JP 2015-21594 A Japanese Patent No. 4907390

  By the way, when the input gear shaft of the gear device that amplifies the torque difference of the vehicle drive device is directly connected to the electric motor and the output shaft of the gear device is connected to the drive wheel, the electric motor of the electric motor matched to the drive torque required for the drive wheel is obtained. Since driving force (torque) is required, the electric motor is increased in size. For this reason, the vehicle drive device has several gear shafts as a reduction mechanism that increases the torque of the electric motor and transmits it to the drive wheels. The gear shaft is connected to the motor shaft of the electric motor and has an input gear shaft having a small-diameter gear as an input gear, and at least one intermediate gear that transmits power by meshing the gear between the input gear shaft and the output shaft. The gear shaft is arranged.

  In the prior art 1 and the prior art 2, the arrangement of the gear device in the vehicle drive device is not specifically mentioned. However, when the gear device is provided on the output side of the speed reduction mechanism, components for the output torque (gear, bearing, etc.) ), The component parts are enlarged, resulting in a larger vehicle drive device and higher production costs.

  Further, when the gear device is provided on the input side of the speed reduction mechanism, each gear of the planetary gear mechanism constituting the gear device rotates at high speed, and frictional heat due to slippage between the gear tooth surfaces tends to occur. When lubricating oil is used for cooling the gear tooth surfaces, the configuration becomes complicated by connecting two planetary gear mechanisms, and it may be difficult to secure a lubricating oil path inside the gear device.

  Further, in order to prevent abnormal wear due to contact between the tooth surfaces of the gears, it is necessary to ensure the rotation accuracy of the gear shaft, such as a bearing configuration. There is no description.

  By the way, the applicant of the present application has already filed a patent application for a vehicle drive device that is smaller and lighter than the gear device that amplifies the torque difference between the prior art 1 and the prior art 2 (Japanese Patent Application No. 2006-023529). issue).

  The vehicle drive device (prior application example 1) for which the applicant of this application has applied for a patent has the configuration shown in FIGS. 19 and 20.

  As shown in FIG. 19, the vehicle drive device 201 of the first application example includes two electric motors 202L and 202R that are mounted on a vehicle and can be controlled independently, two electric motors 202L and 202R, and left and right drive wheels. A gear device 300 provided between the two electric motors 202L and 202R and distributing the torque from the two electric motors 202L to the left and right wheels, and reduction gears 203L and 203R transmitting the torques of the two electric motors 202L and 202R to the drive wheels. Yes. The reduction gears 203L and 203R are connected to electric motors 202L and 202R, input gear shafts 212L and 212R having an input gear 212a, output shafts 214L and 214R connected to driving wheels and having an output gear 214a, and gears Intermediate gear shafts 213L and 213R that transmit power between the input gear shafts 212L and 212R and the output shafts 214L and 214R by meshing, and the gears constituting the reduction gears 203L and 203R are external gears.

  As the two electric motors 202L and 202R, electric motors having the same output characteristics are used, and are housed in motor housings 204L and 204R as shown in FIG.

  The input gear shafts 212L and 212R, the intermediate gear shafts 213L and 213R, and the output shafts 214L and 214R are arranged offset from each other.

The gear device 300 that distributes torque from the two electric motors 202L and 202R to the left and right wheels is a three-element two-degree-of-freedom combination that is coaxially combined with a pair of left and right intermediate gear shafts 213L and 213R. The planetary gear mechanism. Planetary gear mechanism, the internal gear R _L, and R _R, the internal gear R _L, R _R and planet carrier C _L provided coaxially, and C _R, the internal gear R _L, on R _R coaxial provided sun gear S _L, and S _R, the planetary gear P _L as a revolving wheel, and a P _R, and one of the planet carrier C _L and the other of the sun gear S _R of the two planetary gear mechanism a first coupling member 231 for coupling, and a second coupling member 232 for coupling the one of the sun gear S _L and the other planet carrier C _R, the intermediate gear shaft 213L in the gear device 300 and coaxially to 213R, an input-side external gear 213a meshing with the input gear 212a, a planet carrier C _L of the planetary gear mechanism, is connected to the C _R, and an output-side small-diameter gear 213b meshing with the output gear 214a provided, the planet carrier C _L , C across _R is the rolling bearing 219a, 219 Is a structure that is rotatably supported on the housing 209 for accommodating the gear 300 by.

In the prior application example 1, as described above, in order to install the gear device 300 on the intermediate gear shafts 213L and 213R of the vehicle drive device 201, the sun gears S _L and S constituting the two planetary gear mechanisms of the gear device 300 are provided. _R , planet carriers C _L , C _R , planetary gears P _L , P _R , and internal gears R _L , R _R installation space and intermediate gear shafts 213L, 213R are supported at both ends of the planet carriers C _L , C _R. Installation space for the rolling bearings 219a and 219b is required, and the axial dimension is increased.

  In the structure in which the electric motors 202L and 202R and the output shafts 214L and 214R are offset, the portions of the electric motors 202L and 202R are the longest in the axial direction. In the vehicle drive device shown in FIG. 19, since the gear device 300 and the parallel shaft gear reduction device are integrated, the input gear 212a connected to the electric motors 202L and 202R is constituted by a small gear. The input side external gear 213a meshing with 212a is a large-diameter gear. Since the input gear 212a connected to the electric motors 202L and 202R is smaller than the stator diameter of the electric motors 202L and 202R, the electric motors 202L and 202R and the gear device 300 overlap in the axial direction.

  As described above, the gear device 300 requires an axial length, and the gear device 300 and the electric motors 202L and 202R overlap in the axial direction, so that the physique of the vehicle drive device becomes longer in the axial direction. For this reason, it is necessary to secure a wide length in the vehicle width direction of the mounting space of the vehicle drive device in the vehicle.

  If the mounting space is wide in the vehicle width direction, the vehicle width becomes wide and the handling of the vehicle in a narrow alley becomes worse. Further, when the vehicle drive device is mounted on the steering wheel, if the vehicle drive device is long in the vehicle width direction, the steering angle is limited, and the turning ability of the vehicle is deteriorated. Furthermore, the structure and arrangement of the suspension device (especially the arm length in the vehicle width direction) is limited, which may lead to disadvantages such as reduced ride comfort and handling stability.

  Therefore, an object of the present invention is to provide a vehicle drive device that can prevent the vehicle drive device from becoming longer in the axial direction and can reduce the mounting space in the vehicle width direction.

  In order to solve the above-described problems, the present invention provides two electric motors mounted on a vehicle and independently controllable, and provided between the two electric motors and left and right drive wheels, and the two electric motors A vehicle drive device comprising: a gear device that distributes torque from the motor to the left and right wheels; and a reduction device that transmits the torques of the two electric motors to the drive wheels. The reduction device is connected to the electric motor, and the input gear. An input gear shaft having an output gear, an output shaft coupled to the drive wheel, and at least one intermediate gear shaft for transmitting power between the input gear shaft and the output shaft by meshing of the gears, the two electric motors The gear device for distributing torque from the left and right wheels comprises a three-element, two-degree-of-freedom planetary gear mechanism that is coaxially combined with a pair of left and right intermediate gear shafts provided coaxially. An idler gear is provided between a large-diameter gear of an intermediate gear shaft to which torque is transmitted from the input gear, and the electric motor is determined by a distance from the center of the motor shaft of the electric motor to the radial end of the stator of the electric motor. The diameter of the idler gear is defined such that the distance from the center of the motor shaft of the motor to the gear device is increased.

  The planetary gear mechanism of the gear device includes an internal gear, a planet carrier provided coaxially with the internal gear, a sun gear provided coaxially with the internal gear, and a planetary gear as a revolving gear. A first coupling member that couples one planet carrier and the other sun gear of the two planetary gear mechanisms, and a second coupling member that couples one sun gear and the other planet carrier. It is characterized by having.

  The planetary gear mechanism includes a sun gear, an internal gear provided coaxially with the sun gear, and a planet carrier provided coaxially with the sun gear, and the gear device includes: A first coupling member that couples one planet carrier and the other sun gear, and a second coupling member that couples one sun gear and the other planet carrier, and the torque of the one electric motor is: The torque of the other electric motor is transmitted to the first coupling member, the torque of one of the driving wheels is transmitted from one internal gear, and the other driving wheel is transmitted to the second coupling member. Torque is transmitted from the other internal gear.

  Further, the gear constituting the speed reduction device is an external gear, the input side external gear meshing with the gear of the idler gear on the intermediate gear shaft of the speed reduction device that is coaxial with the gear device, and the planetary gear mechanism An output side small-diameter gear connected to the carrier and meshing with the output gear or the gear of the driven intermediate gear shaft is provided, and both ends of the planetary carrier are rotatably supported by rolling bearings.

  Each of the planetary gear mechanisms includes an internal gear, a planet carrier provided coaxially with the internal gear, a sun gear provided coaxially with the internal gear, and a planetary gear as a revolving gear. And the input side external gear which meshes | engages with the said idler gear was provided in the outer peripheral part of the said internal gear.

  As described above, according to the present invention, the idler gear is provided between the input gear and the large-diameter gear of the intermediate gear shaft to which torque is transmitted from the input gear. By determining that the distance from the center of the motor shaft of the electric motor to the gear device is larger than the distance from the center of the motor shaft to the radial end of the stator of the electric motor, the electric motor and the gear device are Since it can arrange | position so that it may not overlap when seeing from a direction, and it can arrange | position so that the axial direction distance of two electric motors may become near, the axial direction dimension of a vehicle drive device can be shortened. As a result, the vehicle drive device mounting space can be made smaller in the vehicle width direction, the vehicle width can be reduced, and the vehicle can be handled easily in narrow alleys. Large wheel steering angle, good turning ability of the vehicle, few restrictions on the structure and arrangement of the suspension system, long arm length in the vehicle width direction, good ride comfort and steering stability, etc. can get.

1 is a cross-sectional plan view showing a first embodiment of a vehicle drive device of the present invention. FIG. 2 is a schematic explanatory view taken along line II-II in FIG. 1. It is an enlarged view of the input gear and idler gear part of the embodiment of FIG. It is an enlarged view of the gear apparatus part of embodiment of FIG. It is explanatory drawing of the electric vehicle which showed the gear structure of the vehicle drive device which concerns on embodiment of FIG. 1 with the skeleton figure. It is a speed diagram for demonstrating the torque difference amplification factor by the gear apparatus incorporated in the vehicle drive device which concerns on embodiment of FIG. It is a cross-sectional top view which shows 2nd Embodiment of the vehicle drive device of this invention. FIG. 8 is a schematic explanatory view taken along line VIII-VIII in FIG. 7. FIG. 8 is an enlarged view of an input gear and an idler gear portion of the embodiment of FIG. 7. It is an enlarged view of the gear apparatus part of embodiment of FIG. It is a cross-sectional top view which shows 3rd Embodiment of the vehicle drive device of this invention. FIG. 12 is a schematic explanatory view taken along line XII-XII in FIG. 11. It is an enlarged view of the gear apparatus part of embodiment of FIG. It is explanatory drawing of the electric vehicle which showed the gear structure of the vehicle drive device which concerns on embodiment of FIG. 11 with the skeleton figure. It is a skeleton figure which shows the gear structure of the vehicle drive device which concerns on the prior art 1. FIG. It is a speed diagram for demonstrating the torque difference gain by the gear apparatus integrated in the vehicle drive device which concerns on the prior art 1. FIG. It is a skeleton figure which shows the gear structure of the vehicle drive device which concerns on the prior art 2. FIG. It is a speed diagram for demonstrating the torque difference gain by the gear apparatus integrated in the vehicle drive device which concerns on the prior art 2. FIG. It is a cross-sectional top view which shows the vehicle drive device of prior application example 1. FIG. 20 is an enlarged view of a gear device portion of the vehicle drive device of the first application example shown in FIG. 19.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  The electric vehicle AM shown in FIG. 5 is a rear wheel drive system, and includes a chassis 60, drive wheels 61L and 61R as rear wheels, front wheels 62L and 62R, and a two-motor vehicle drive device 1 according to the present invention. A battery 63, an inverter 64, and the like are provided. In FIG. 5, the gear structure of the vehicle drive device 1 is shown with the skeleton figure.

  1 and FIG. 5 includes an electric motor 2L, 2R as two drive sources mounted on a vehicle and independently controllable, left and right drive wheels 61L, 61R, and two electric motors 2L, 2R left and right reduction gears 3L, 3R provided between 2R. Idler gears 70a and 70a are respectively provided between the input gears 12a and 12a connected to the input gear shafts 12L and 12R of the electric motors 2L and 2R and the reduction gears 3L and 3R. The diameter of the idler gear 70a is such that the distance from the center of the motor shaft 5a of the electric motors 2L and 2R to the gear device 30 is larger than the distance from the center of the motor shaft 5a of the electric motors 2L and 2R to the end of the stator 6. To be decided. Thus, by determining the size of the diameter of the idler gear 70a, the electric motors 2L, 2R and the gear unit 30 provided integrally with the speed reducers 3L, 3R are arranged so as not to overlap each other when viewed from the axial direction. The useless space is compressed and the axial dimension of the vehicle drive device is reduced.

  The drive torque of the two-motor type vehicle drive device 1 is transmitted to the left and right drive wheels 61L and 61R via a drive shaft composed of constant velocity joints 65a and 65b and an intermediate shaft 65c (FIG. 5).

  As a mounting form of the two-motor type vehicle drive device 1, a front wheel drive method and a four wheel drive method may be used in addition to the rear wheel drive method shown in FIG. Further, a four-wheel drive system in which the vehicle drive device 1 drives one of the front wheels or the rear wheels and the other is driven by an internal combustion engine may be used.

  The left and right electric motors 2L and 2R in the two-motor type vehicle drive device 1 use electric motors having the same output characteristics, and are housed in motor housings 4L and 4R as shown in FIG. As shown in FIG. 2 taken along the line II-II in FIG. 1, the input gear shafts 12L and 12R, the idler shafts 70L and 70R, the intermediate gear shafts 13L and 13R, and the output shafts 14L and 14R are arranged offset from each other. Has been.

  As shown in FIG. 1, the motor housings 4L and 4R include cylindrical motor housing bodies 4aL and 4aR, outer walls 4bL and 4bR that close the outer surfaces of the motor housing bodies 4aL and 4aR, and motor housing bodies 4aL, The inner side surface of 4aR is composed of inner side walls 4cL and 4cR separated from the reduction gears 3L and 3R. The inner walls 4cL and 4cR of the motor housing bodies 4aL and 4aR are provided with openings through which the motor shaft 5a is drawn.

  As shown in FIG. 1, the electric motors 2 </ b> L and 2 </ b> R are of a radial gap type in which a stator 6 is provided on the inner peripheral surface of the motor housing body 4 aL and 4 aR, and a rotor 5 is provided on the inner periphery of the stator 6. I am using something. The electric motors 2L and 2R may be axial gap types.

  The rotor 5 has a motor shaft 5a in the center, and the motor shaft 5a is drawn from the openings of the inner walls 4cL and 4cR of the motor housing main bodies 4aL and 4aR to the reduction gears 3L and 3R, respectively. A seal member 18 is provided between the openings of the inner side walls 4cL and 4cR of the motor housing main bodies 4aL and 4aR and the motor shaft 5a to prevent leakage of the lubricating oil sealed in the speed reducer housing 9.

  The motor shaft 5a is rotatably supported by the rolling bearings 8a and 8b on the inner walls 4cL and 4cR and the outer walls 4bL and 4bR of the motor housing main bodies 4aL and 4aR (FIG. 1).

  A reduction gear housing 9 that accommodates two reduction gears 3L and 3R provided in parallel on the left and right is divided into three pieces in a direction perpendicular to the gear shafts of the reduction gears 3L and 3R, as shown in FIG. The housing 9a has a three-piece structure including left and right side housings 9bL and 9bR fixed to both side surfaces of the central housing 9a. The left and right side housings 9bL and 9bR are fixed to the openings on both sides of the central housing 9a by a plurality of bolts (not shown).

  The side surface of the side housings 9bL and 9bR of the reduction gear housing 9 on the outboard side (outside the vehicle body) and the inner side walls 4cL and 4cR of the motor housing bodies 4aL and 4aR of the electric motors 2L and 2R are integrated (FIG. 1). ). The side surfaces of the side housings 9bL and 9bR on the outboard side and the motor housing main bodies 4aL and 4aR of the electric motors 2L and 2R are separated from each other, and the electric motors 2L and 2R are transferred to the side housings 9bL and 9bR. The two electric motors 2L and 2R may be fixedly arranged on the left and right of the reduction gear housing 9 by fixing the inner side walls 4cL and 4cR of the motor housing bodies 4aL and 4aR with a plurality of bolts.

  As shown in FIG. 1, the central housing 9a is provided with a partition wall 11 at the center. The speed reducer housing 9 is divided into left and right parts by the partition wall 11, and independent left and right accommodation chambers for accommodating the two speed reducers 3L and 3R are provided in parallel.

  As shown in FIG. 1, the reduction gears 3L, 3R are provided symmetrically, torque is transmitted from the motor shaft 5a, input gear shafts 12L, 12R having an input gear 12a, and torque from the input gear 12a. Is provided with intermediate gear shafts 13L and 13R having an output-side small gear 13b meshing with a large-diameter input-side external gear 13a and an output gear 14a, and an output gear 14a. This is a parallel shaft gear reducer including output shafts 14L and 14R that transmit torque to drive wheels 61L and 61R via joints 65a and 65b and an intermediate shaft 65c (FIG. 5).

  An idler gear 70a that meshes with both gears is provided between the input gear 12a and the input side external gear 13a. The idler shafts 70L and 70R having the idler gear 70a are provided between the input gear shafts 12L and 12R and the intermediate gear shafts 13L and 13R.

  The input gear shafts 12L and 12R, the idler shafts 70L and 70R, the intermediate gear shafts 13L and 13R, and the output shafts 14L and 14R of the left and right reduction gears 3L and 3R are coaxially arranged. .

  Both ends of the input gear shafts 12L, 12R of the reduction gears 3L, 3R roll into bearing fitting holes 16a formed on both the left and right sides of the partition wall 11 of the central housing 9a and bearing fitting holes 16b formed in the side housings 9bL, 9bR. The bearings 17a and 17b are rotatably supported. The bearing fitting holes 16a and 16b have a stepped shape having a wall portion with which the outer rings of the rolling bearings 17a and 17b abut.

  The input gear shafts 12L and 12R have a hollow structure, and the end portions on the outboard side of the hollow input gear shafts 12L and 12R are drawn out from the openings provided in the side housings 9bL and 9bR to the electric motors 2L and 2R. The end of the motor shaft 5a is inserted. The input gear shafts 12L, 12R and the motor shaft 5a are connected by splines (including the same for serrations).

  An idler gear 70a meshing with the input gear 12a meshes with a large-diameter input side external gear 13a provided on the intermediate gear shafts 13L and 13R, and transmits the torque of the input gear 12a to the input side external gear 13a.

  As shown in the enlarged view of FIG. 3, both ends of the idler shafts 70L and 70R having the idler gear 70a are connected to a bearing fitting hole 71b formed in the side housings 9bL and 9bR and a bearing fitting hole 71a formed in the central housing 9a. It is supported via rolling bearings 72a and 72b. And the bearing fitting holes 71a and 71b have a stepped shape having a wall portion with which the outer rings of the rolling bearings 72a and 72b abut.

  As shown in FIGS. 1 and 2, the idler gear 70a has a diameter that does not overlap a gear device 30 that is a torque difference amplification mechanism, which will be described later, and the electric motors 2L and 2R when viewed in the axial direction. That is, the idler gear so that the distance from the center of the motor shaft 5a of the electric motors 2L and 2R to the gear device 30 is larger than the distance from the center of the motor shaft 5a of the electric motors 2L and 2R to the radial end of the stator 6. The size of the diameter of 70a is determined. By providing the idler gear 70a having a diameter determined as described above, the distance between the shaft centers of the electric motors 2L and 2R and the planetary gear mechanisms 30L and 30R of the gear device 30 which is a torque difference amplification mechanism is increased, thereby amplifying the torque difference. The gear device 30 which is a mechanism and the electric motors 2L and 2R are prevented from overlapping when viewed from the axial direction.

  At least a pair of intermediate gear shafts 13L and 13R are arranged. In the embodiment shown in FIG. 1, the intermediate gear shafts 13L and 13R have a pair of intermediate gear shafts 13L and 13R.

  The intermediate gear shafts 13L and 13R constitute a stepped gear shaft having an input side external gear 13a meshing with the idler gear 70a and an output side small diameter gear 13b meshing with the output gear 14a on the outer peripheral surface. Both ends of the intermediate gear shafts 13L and 13R are inserted into bearing fitting holes 19a formed on both surfaces of the partition wall 11 of the central housing 9a and bearing fitting holes 19b formed on the side housings 9bL and 9bR via rolling bearings 20a and 20b. It is supported. And the bearing fitting hole 19a becomes a stepped shape with the wall part which the outer ring | wheel of the rolling bearing 20a contact | abuts, and has penetrated so that the 1st coupling member 31 mentioned later and the 2nd coupling member 32 may pass. .

  The intermediate gear shafts 13L and 13R arranged on the same axis have a torque difference between the left and right drive wheels 61L and 61R on the same axis as the intermediate gear shafts 13L and 13R. A gear device 30 for amplifying and distributing is incorporated.

  As described above, the idler gear 70a is arranged so that the gear device 30 that is a torque difference amplification mechanism and the electric motors 2L and 2R do not overlap each other when viewed in the axial direction, so that the intermediate gear shafts 13L and 13R are supported. The rolling bearings 20a and 20b are also positioned so as not to overlap the stator 6 of the electric motors 2L and 2R. For this reason, the electric motors 2L and 2R can be arranged closer to the inboard side than the distance between the rolling bearing 20b of the intermediate gear shaft 13L and the rolling bearing 20b of the intermediate gear shaft 13R. As a result, the axial length can be made shorter than the conventional vehicle drive device shown in FIG.

  The gear device 30 is composed of a planetary gear mechanism having three elements and two degrees of freedom, which are combined on the same axis.

As shown in the enlarged view of FIG. 4, the planetary gear mechanism constituting the gear device 30 includes internal gears R _L and R _R incorporated in the large-diameter input-side external gear 13a of the intermediate gear shafts 13L and 13R, internal gear R _L, R _R and the sun gear S _L provided coaxially, S _R and internal gear R _L, R _R and the sun gear S _L, the planetary gear P _L as a revolving gear meshing with S _R, P and _R, the planetary gear P _L, is connected to the P _R, the internal gear R _L, R _R and the sun gear S _L, S _R and the planet carrier C _L provided coaxially, C _R and, one of the planet carrier C _A first coupling member 31 that couples _L (left side of the figure in FIG. 4) and the other sun gear S _R (right side of the figure in FIG. 4), one sun gear S _L (left side of the figure in FIG. 4), and A second coupling member 32 that couples the other planet carrier C _R (right side of the figure in FIG. 4) and an eye connected to the internal gears R _L and R _R. The intermediate gear shafts 13L and 13R are engaged with the idler gear 70a of the drive shafts 70L and 70R, and the output side small gear 13b of the intermediate gear shafts 13L and 13R is engaged with the output gear 14a of the output shafts 14L and 14R. The output side small-diameter gear 13b of the intermediate gear shafts 13L and 13R is connected to the planetary carriers C _L and C _R.

When a plurality of pairs of intermediate gear shafts 13L and 13R are provided, the internal gears R _L and R _R connected to the input-side external gear 13a are connected to the idler gear 70a among the plurality of pairs of intermediate gear shafts 13L and 13R. The input-side external gear 13a is arranged to mesh with the output-side small-diameter gear 13b so as to mesh with gears provided on the driven-side intermediate gear shafts 13L, 13R of the plural pairs of intermediate gear shafts 13L, 13R. Is done.

In the embodiment shown in FIGS. 1 and 4, the internal gear R _L, the input-side external gear 13a which is connected to R _R is the internal gear R _L, are formed integrally with the R _R.

Planet carrier C _L, C _R is the planetary gears P _L, a carrier pin 33 which supports the P _R, and the carrier flange 34a on the outboard side which is connected to the outboard side end portion of the carrier pin 33, inboard end And an inboard carrier flange 34b connected to the portion.

  The carrier flange 34a on the outboard side includes a hollow shaft portion 35 extending toward the outboard side, and the end portion on the outboard side of the hollow shaft portion 35 is formed on the side housings 9bL and 9bR of the speed reducer housing 9. The fitting hole 19b is supported via a rolling bearing 20b.

  The carrier flange 34b on the inboard side includes a hollow shaft portion 36 extending toward the inboard side, and an end portion on the inboard side of the hollow shaft portion 36 is formed in a bearing fitting hole formed in the partition wall 11 of the central housing 9a. 19a is supported via a rolling bearing 20a. In the embodiment shown in FIGS. 1 and 4, the hollow shaft portion 36 of the intermediate gear shaft 13 </ b> R is formed integrally with the second coupling member 32.

  In the embodiment shown in FIG. 4, the output-side small-diameter gear 13b is integrally formed on the outer peripheral surface of the hollow shaft portion 35 of the carrier flange 34a.

The planetary gears P _L and P _R are supported by the carrier pin 33 via the needle roller bearing 37.

Further, each carrier flange 34a, 34b facing surface and a planetary gear P _L of, inserting the thrust plate 38 between the P _R, the planetary gear P _L, thereby achieving a smooth rotation of the P _R.

Wherein each carrier flange 34a, 34b outer peripheral surface and the inner gear R _L of the, between the R _R, the rolling bearing 39a, are arranged 39 b.

  A collar 40 is disposed between the carrier flange 34b on the inboard side and the rolling bearing 20a that supports the hollow shaft portion 36 of the carrier flange 34b on the inboard side.

  The first coupling member 31 and the second coupling member 32 that couple the two planetary gear mechanisms that constitute the gear device 30 of the vehicle drive device 1 define the partition wall 11 that partitions the central housing 9a of the reduction gear housing 9 to the left and right. It is built through.

  The first coupling member 31 and the second coupling member 32 are arranged coaxially, and one coupling member (the second coupling member 32 in the embodiment of FIGS. 1 and 4) is a hollow shaft, and the other coupling member. (In the embodiment of FIGS. 1 and 4, the first coupling member 31) has a double structure including a shaft inserted through the hollow shaft.

In the embodiment shown in FIGS. 1 and 4, the end portion of the right side of the planetary gear mechanism 30R side of the second coupling member 32 consists of a hollow shaft, the hollow shaft of the carrier flange 34b on the inboard side of the planet carrier C _R Although the part 36 is integrally formed, the second coupling member 32 and the hollow shaft part 36 may be separated and may be splined together.

Further, in the embodiment shown in FIGS. 1 and 4, the end portion of the left planetary gear mechanism 30L side of the first coupling member 31, to the hollow shaft portion 35 of the carrier flange 34a on the outboard side of the planet carrier C _L the spline 42 is provided, it is connected by spline fitting to the first coupling member 31 the planet carrier C _L.

End of the planetary gear mechanism 30L side of the second coupling member 32 has, on its outer peripheral surface, the external gear is formed to mesh with the planetary gears P _L of the planetary gear mechanism 30L, the sun gear S of the outer gear planetary gear mechanism 30L _L is composed.

The first coupling member 31 inserted through the second coupling member 32 constituted by a hollow shaft has a large-diameter portion 43 at an end portion on the planetary gear mechanism 30R side. external gear meshing with the planetary gears P _R of the gear mechanism 30R is formed, the outer gear constitutes the sun gear S _R of the planetary gear mechanism 30R.

  Between the outer peripheral surface of the inner diameter side coupling member (first coupling member 31) and the inner peripheral surface of the outer diameter side coupling member (second coupling member 32), there are needles 44 at both ends of the collar 44. The roller bearings 45 and 46 are interposed.

The coupling member (the first coupling member 31 in the embodiment of FIGS. 1 and 4) on the inner diameter side of the double-structure shaft that couples the two planetary gear mechanisms is the coupling member (the first coupling member 31 in the embodiment of FIGS. 1 and 4). 1 coupling member 31) and the planetary carrier (C _{L in the} embodiment of FIGS. 1 and 4) on the opposite shaft end from the spline fitting, and the other planet carrier (C _{R in the} embodiment of FIGS. 1 and 4). ) Is supported by a deep groove ball bearing 49.

  As shown in FIGS. 1 and 4, the output shafts 14L and 14R have a large-diameter output gear 14a, bearing fitting holes 53a formed on both surfaces of the partition wall 11 of the central housing 9a, and side housings 9bL and 9bR. Are supported by rolling bearings 54a and 54b. The bearing fitting holes 53a and 53b have a stepped shape having a wall portion with which the outer rings of the rolling bearings 54a and 54b come into contact.

  Outboard end portions of the output shafts 14L and 14R are drawn out of the reduction gear housing 9 from openings formed in the side housings 9bL and 9bR, and are pulled out to the outer end portions of the output shafts 14L and 14R. The outer joint portion of the constant velocity joint 65a is spline-coupled to the inner peripheral surface.

  The constant velocity joint 65a coupled to the output shafts 14L and 14R is connected to the drive wheels 61L and 61R via the intermediate shaft 65c and the constant velocity joint 65b (FIG. 5).

  An oil seal 55 is provided between the end of the output shaft 14L, 14R on the outboard side and the opening formed in the side housings 9bL, 9bR, and leakage of the lubricating oil sealed in the reduction gear housing 9 and from the outside Prevents intrusion of muddy water.

In this embodiment, the internal gear R _L, the input-side external gear 13a which is connected to R _R is the internal gear R _L, are formed integrally with the R _R. Each of the input-side external gears 13a is caused by the planetary gear trains of the sun gears S _L and S _R , the planetary gears P _L and P _R , and the internal gears R _L and R _R of the planetary gear mechanism 30L and the planetary gear mechanism 30R. It is arranged at the position sandwiched in the axial direction (inboard side). With this configuration, the idler gear 70a for transmitting torque to the input side external gear 13a and the input gear 12a can be arranged close to the inboard side of the vehicle drive device 1, and the two electric motors 2L, 2R can be arranged close to the axial direction. For this reason, the axial direction dimension of the vehicle drive device 1 can be reduced.

Similarly, in the gear device 30, each of the input-side external gears 13a connected to the internal gears R _L and R _R is sandwiched in the axial direction by the gear 13b that transmits torque to the next reduction portion (inboard side). ), The idler gear 70a for transmitting torque to the input side external gear 13a and the input gear 12a can be arranged close to the inboard side of the vehicle drive device 1, and the two electric motors 2L, 2R can be arranged. Can be arranged close to the axial direction. For this reason, the axial direction dimension of the vehicle drive device 1 can be reduced.

As shown in FIGS. 1 and 2, when viewed from the axial direction, the electric motors 2 </ b> L and 2 </ b> R overlap with the input-side external gear 13 a, but do not overlap with the internal gears R _L and R _{R of the} gear device 30. With the idler gear 70a, the gear device 30 is disposed at a position that does not overlap the stator 6 of the electric motors 2L and 2R.

  The gear configuration of the two-motor vehicle drive device 1 of the embodiment shown in FIG. 1 is as shown in the skeleton diagram of FIG.

  As shown in FIG. 5, the left and right electric motors 2 </ b> L and 2 </ b> R are operated by electric power supplied from a battery 63 mounted on the vehicle via an inverter 64. The electric motors 2L and 2R are individually controlled by an electronic control device (not shown), and can generate and output different torques.

The torques of the motor shafts 5a of the electric motors 2L and 2R are the gear ratio between the input gear shafts 12a of the reduction gears 3L and 3R and the idler gears 70a of the idler shafts 70L and 70R, and the idler gears 70a and the intermediate gear shafts. 13L, the internal gear R _L of being increased by the gear ratio between the input side external gear 13a of the large diameter 13R gear 30 is transmitted to R _R.

  Then, the output side small gear 13b of the intermediate gear shafts 13L and 13R meshes with the large diameter output gear 14a of the output shafts 14L and 14R via the gear device 30, and the gear ratio between the output side small gear 13b and the output gear 14a. Thus, the torque of the motor shaft 5a of the electric motors 2L and 2R is further increased and output to the drive wheels 61L and 61R.

  The gear device 30 is configured by combining two identical planetary gear mechanisms having three elements and two degrees of freedom with coaxial intermediate gear shafts 13L and 13R, and adopts a single pinion planetary gear mechanism as the planetary gear mechanism. .

The planetary gear mechanism is positioned between the sun gears S _L and S _R and the internal gears R _L and R _R provided on the same axis, and between the sun gears S _L and S _R and the internal gears R _L and R _R. A plurality of planetary gears P _L and P _R and planetary gears P _L and P _R are rotatably supported, and planet carriers C _L provided coaxially with the sun gears S _L and S _R and the internal gears R _L and R _R. composed of a C _R. Here, the sun gears S _L and S _R and the planetary gears P _L and P _R are external gears having gear teeth on the outer periphery, and the internal gears R _L and R _R are internal gears having gear teeth on the inner periphery. The planetary gears P _L and P _R mesh with the sun gears S _L and S _R and the internal gears R _L and R _R.

In the single pinion planetary gear mechanism, when the planetary carriers C _L and C _R are fixed, the sun gears S _L and S _R and the internal gears R _L and R _R rotate in opposite directions. , The internal gears R _L , R _R and the sun gears S _L , S _R are arranged on the opposite side to the planet carriers C _L , C _R.

As described above, the gear device 30 includes the first planetary gear mechanism 30L having the sun gear S _L , the planet carrier C _L , the planetary gear P _L, and the internal gear _RL , the sun gear S _R , and the planet carrier C _R. a second planetary gear mechanism 30R having a planetary gear P _R and the internal gear R _R is configured by combining coaxially.

Then, the planet carrier C _L of the first planetary gear mechanism 30L is binding and the sun gear S _R of the second planetary gear mechanism 30R to form a first coupling member 31, the sun gear S _L of the first planetary gear mechanism 30L When the planet carrier C _R of the second planetary gear mechanism 30R form a second coupling member 32 are coupled.

  Torque TM1 generated by the electric motor 2L is transmitted to the intermediate gear shaft 13L by meshing between the input gear 12a of the input gear shaft 12L and the idler gear 70a of the idler shaft 70L, and meshing between the idler gear 70a of the idler shaft 70L and the input side external gear 13a. The torque transmitted to the intermediate gear shaft 13L is transmitted to the output-side small-diameter gear 13b of the intermediate gear shaft 13L via the first planetary gear mechanism 30L, and the output-side small-diameter gear 13b and the output shaft 14L of the intermediate gear shaft 13L. The output gear 14a meshes with the output gear 14a, and the drive torque TL is output from the output shaft 14L to the drive wheel 61L.

  Torque TM2 generated by the electric motor 2R is transmitted to the intermediate gear shaft 13R through the engagement of the input gear 12a of the input gear shaft 12R and the idler gear 70a of the idler shaft 70R, and the idler gear 70a of the idler shaft 70R and the input side external gear 13a. The torque transmitted to the intermediate gear shaft 13R is transmitted to the output-side small-diameter gear 13b of the intermediate gear shaft 13R via the second planetary gear mechanism 30R, and the output-side small-diameter gear 13b and the output shaft 14R of the intermediate gear shaft 13R. And the output gear 14a mesh with each other, and the drive torque TR is output from the output shaft 14R to the drive wheel 61R.

Motor torques from the electric motors 2L and 2R are given to the internal gears R _L and R _R of the two planetary gear mechanisms, and outputs from the first coupling member 31 and the second coupling member 32 are drive wheels 61L and 61R. Given to.

  The 2nd coupling member 32 is comprised by the hollow shaft, the 1st coupling member 31 is penetrated in the inside, and the axis | shaft which comprises the 1st coupling member 31 and the 2nd coupling member 32 has a double structure. .

The first coupling member 31 has one end a rotation shaft of the (right end in the drawing) is the sun gear S _R, the other end (left end in the drawing) are provided through the sun gear S _L, connected to the planet carrier C _L Has been. The second coupling member 32 is a hollow shaft, one end (left end in the drawing) has a rotation shaft of the sun gear S _L, the other end (right end in the drawing) is connected to the planet carrier C _R. Two planetary gear mechanisms are coupled by the first coupling member 31 and the second coupling member 32.

Since the gear device 30 is configured by combining two planetary gear mechanisms of the same single pinion type, it can be represented by two velocity diagrams as shown in FIG. Here, for easy understanding, the two speed diagrams are shifted up and down, the speed diagram of the left planetary gear mechanism 30L is shown on the upper side, and the speed diagram of the right planetary gear mechanism 30R is shown on the lower side. Further, originally, in the embodiment of FIG. 1, the motor torques TM1 and TM2 output from the electric motors 2L and 2R are input to the input gears 12a of the input gear shafts 12L and 12R via the idler gears 70a of the idler shafts 70L and 70R. The input side external gear 13a meshes with the internal gears R _L and R _R so that a reduction ratio is applied, and the drive torques TL and TR extracted from the gear device 30 are output side small diameters meshed with the output gear 14a. Since it is transmitted to the left and right drive wheels 61L and 61R via the gear 13b, a reduction ratio is applied. However, for the sake of easy understanding, in the explanation of the speed diagram and each calculation formula shown in FIG. Omitted, the torque input to the internal gears R _L and R _R remains TM1 and TM2, and the drive torque remains TL and TR.

Two planetary gear mechanism constituting the gear device 30, due to the use of gear elements of the same number of teeth, in the speed diagram and distance and the internal gear R _R of the internal gear R _L and the planet carrier C _L the distance between the planet carrier C _R are equal, which is referred to as a. Further, the distance between the sun gear S _L and the planet carrier C _L and the distance between the sun gear S _R and the planet carrier C _R are also equal, which is b. The ratio of the length from the planet carrier C _L , C _R to the internal gear R _L , R _R and the length from the planet carrier C _L , C _R to the sun gear S _L , S _R is the ratio of the internal gear R _L , R _R It is equal to the ratio of the reciprocal number (1 / Zr) of the number of teeth Zr and the reciprocal number (1 / Zs) of the number of teeth Zs of the sun gears S _L and S _R. Therefore, a = (1 / Zr) and b = (1 / Zs).

The following equation (11) is calculated from the balance of the moment M with respect to the point of the internal gear R _R. In FIG. 6, the arrow direction in the figure is the positive direction of the moment M.
a * TR + (a + b) * TL- (b + 2a) * TM1 = 0 (11)

The following equation (12) is calculated from the balance of the moment M based on the point of the internal gear _RL .
-A.TL- (a + b) .TR + (b + 2a) .TM2 = 0 (12)

The following expression (13) is obtained from the expression (11) + the expression (12).
-B. (TR-TL) + (2a + b). (TM2-TM1) = 0
(TR-TL) = ((2a + b) / b). (TM2-TM1) (13)

  (2a + b) / b in the equation (13) is the torque difference amplification factor α. When a = 1 / Zr and b = 1 / Zs are substituted, α = (Zr + 2Zs) / Zr, and the following torque difference amplification factor α is obtained.

  α = (Zr + 2Zs) / Zr

In the present invention, the input from the electric motors 2L and 2R is the internal gears R _L and R _R , and the outputs to the drive wheels 61L and 61R are the sun gear S _R and the planet carrier C _L , and the sun gear S _L and the planet carrier C. _R.

  Then, when different torques TM1 and TM2 are generated by the two electric motors 2L and 2R to give an input torque difference ΔTIN (= TM2−TM1), the gear device 30 amplifies the input torque difference ΔTIN, and the input torque difference ΔTIN Large driving torque difference α · ΔTIN can be obtained. That is, even if the input torque difference ΔTIN is small, the input torque difference ΔTIN can be amplified by the above-described torque difference amplification factor α (= (Zr + 2Zs) / Zr) in the gear device 30, and the left drive wheel 61L and the right drive wheel A driving torque difference ΔTOUT (= α · (TM2−TM1) = TR−TL) larger than the input torque difference ΔTIN can be given to the driving torques TL and TR transmitted to 61R.

In the first embodiment of the present invention, the connection between the two planetary gear mechanisms constituting the gear device 30 that is the torque difference distribution mechanism is the sun gear S _L and the planet carrier C _R , and the sun gear S _R and the planet carrier C _L. Therefore, a connecting member having a larger diameter than the internal gears R _L and R _R is not required. For this reason, in the first embodiment, the torque difference distribution mechanism can be made smaller than those of the prior art 1 and the prior art 2, so that the vehicle drive device for an electric vehicle incorporating the torque difference distribution mechanism is provided. 1 can be reduced in size and weight.

  Next, a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, the planetary gear mechanism 80 is used for the next reduction of the gear device 30. Since other configurations are the same as those of the first embodiment, the same portions are denoted by the same reference numerals, and description thereof is omitted here.

  As shown in FIGS. 7 and 8, in order to secure a space for arranging the planetary gear mechanism 80 used for the reduction, the sum of the diameter of the input gear 12a and the diameter of the idler gear 70a is made larger than that of the first embodiment, and the gear device 30 is used. The input side external gear 13a is also at a position that does not overlap the electric motors 2L, 2R. The reduction ratio is slightly different from that of the first embodiment.

  As shown in FIG. 8, which is a cross-section taken along the line VIII-VIII in FIG. 7, the idler gear 70a has such a size that the gear device 30 that is a torque difference amplifying mechanism and the electric motors 2L and 2R do not overlap when viewed from the axial direction. Have a diameter. That is, the idler gear so that the distance from the center of the motor shaft 5a of the electric motors 2L and 2R to the gear device 30 is larger than the distance from the center of the motor shaft 5a of the electric motors 2L and 2R to the radial end of the stator 6. The size of the diameter of 70a is determined. By providing the idler gear 70a having a diameter determined as described above, the distance between the shaft centers of the electric motors 2L and 2R and the planetary gear mechanisms 30L and 30R of the gear device 30 which is a torque difference amplification mechanism is increased, thereby amplifying the torque difference. The gear device 30 which is a mechanism and the electric motors 2L and 2R are prevented from overlapping when viewed from the axial direction.

  As shown in the enlarged view of FIG. 9, both ends of the idler shafts 70L and 70R having the idler gear 70a are connected to a bearing fitting hole 71b formed in the side housings 9bL and 9bR and a bearing fitting hole 71a formed in the central housing 9a. It is supported via rolling bearings 72a and 72b. And the bearing fitting holes 71a and 71b have a stepped shape having a wall portion with which the outer rings of the rolling bearings 72a and 72b abut.

  As shown in the enlarged view of FIG. 10, in the second embodiment, reduction gear housings 9cL and 9cR for accommodating the planetary gear mechanism 80 are provided on the outboard side of the side housings 9bL and 9bR, respectively. Internal gears 81L and 81R are provided on the inner periphery of the reduction gear housings 9cL and 9cR. The planetary gears 82L and 82R meshing with the inner gears 81L and 81R are supported by the carrier pin 83 on the inboard planetary carrier 84a and the outboard planetary carrier 84b via needle roller bearings 89.

  The gear device 30 is composed of a planetary gear mechanism having three elements and two degrees of freedom, which are combined in the same coaxial manner as in the first embodiment. The planetary gear mechanism constituting the gear device 30 is the same as the configuration of the enlarged view of FIG. 4 described above.

  The carrier flange 34a on the outboard side of the gear device 30 is pulled out from the openings of the side housings 9bL and 9bR to the reduction gear housings 9cL and 9cR that accommodate the planetary gear mechanism 80, respectively. A sun gear 85 of the planetary gear mechanism 80 is provided on the outer peripheral surface of the carrier flange 34a and meshes with the planetary gears 82L and 82R.

  The carrier flange 84c of the inboard planetary carrier 84a is rotatably supported by rolling bearings 86 provided on the side housings 9bL and 9bR. The carrier flange 84c is hollow, and the hollow shaft portion 35 of the carrier flange 34a is disposed on the inner periphery.

  The carrier flange 84d of the planetary carrier 84b on the outboard side is rotatably supported by rolling bearings 87 provided in the reducer housings 9cL and 9cR. The carrier flange 84d is hollow, and the outer joint portion of the constant velocity joint 65a is splined to the inner peripheral surface. A seal member 88 is provided between the openings of the reduction gear housings 9cL and 9cR and the outer peripheral surface of the outer joint portion of the constant velocity joint 65a, and the lubricating oil sealed in the reduction gear housing 9 by the seal member 88 is provided. It prevents leakage and intrusion of muddy water from the outside.

  Torque from the gear unit 30 is applied to the sun gear 85 provided on the outer peripheral surface of the hollow shaft portion 35 of the carrier flange 34a. The planetary gears 82L and 82R meshing with the sun gear 85 revolve while rotating, rotate the planetary carriers 84a and 84b while decelerating, and torque is transmitted to the constant velocity joint 65a coupled to the carrier flange 84d.

  In the second embodiment, since the planetary gear mechanism 80 used for reduction is arranged on the outboard side of the gear device 30, the dimension in the direction orthogonal to the axis can be made shorter than that in the first embodiment.

Next, a third embodiment of the present invention will be described with reference to FIGS.
The electric vehicle AM shown in FIG. 14 is a rear wheel drive system, and includes a chassis 60, drive wheels 61L and 61R as rear wheels, front wheels 62L and 62R, and a two-motor vehicle drive device 1 according to the present invention. A battery 63, an inverter 64, and the like are provided. In FIG. 14, the gear structure of the vehicle drive device 1 is shown with the skeleton figure.

  The vehicle drive device 1 shown in FIGS. 11 and 14 is equipped with electric motors 2L and 2R, which are mounted on a vehicle and can be controlled independently, left and right drive wheels 61L and 61R, and two electric motors 2L, 2R left and right reduction gears 3L, 3R provided between 2R. The idler gears 70a and 70a are provided between the input gear shafts 12L and 12R having the input gear 12a connected to the motor shaft 5a of the electric motors 2L and 2R and the input side external gear 13a of the gear device 30, respectively. As described above, the electric motors 2L and 2R and the gear unit 30 provided integrally with the speed reducers 3L and 3R are arranged so as not to overlap each other when viewed in the axial direction, thereby compressing a useless space and the vehicle drive device. The axial dimension of is reduced.

  As shown in FIG. 12, which is a cross-section taken along line XII-XII in FIG. It has a diameter. That is, the idler gear so that the distance from the center of the motor shaft 5a of the electric motors 2L and 2R to the gear device 30 is larger than the distance from the center of the motor shaft 5a of the electric motors 2L and 2R to the radial end of the stator 6. The size of the diameter of 70a is determined. By providing the idler gear 70a having a diameter determined as described above, the distance between the shaft centers of the electric motors 2L and 2R and the planetary gear mechanisms 30L and 30R of the gear device 30 which is a torque difference amplification mechanism is increased, thereby amplifying the torque difference. The gear device 30 which is a mechanism and the electric motors 2L and 2R are prevented from overlapping when viewed from the axial direction.

  The drive torque of the two-motor type vehicle drive device 1 is transmitted to the left and right drive wheels 61L and 61R via a drive shaft composed of constant velocity joints 65a and 65b and an intermediate shaft 65c.

  As a mounting form of the two-motor type vehicle drive device 1, a front wheel drive method and a four wheel drive method may be used in addition to the rear wheel drive method shown in FIG. Further, a four-wheel drive system in which the vehicle drive device 1 drives one of the front wheels or the rear wheels and the other is driven by an internal combustion engine may be used.

  In the third embodiment, a double pinion planetary gear mechanism having two planetary gears similar to the prior art 1 is employed in the gear device 30. Since other configurations are the same as those of the first embodiment, the same portions are denoted by the same reference numerals, and description thereof is omitted here.

As shown in FIG. 14, the gear device 30 includes a first planetary gear mechanism 30L having a sun gear S _L , a planetary carrier C _L , a planetary gear P _L and an internal gear _RL , as well as the sun gear S _R and the planet carrier. C _R, and a second planetary gear mechanism 30R having a planetary gear P _R and the internal gear R _R is configured by combining coaxially.

Then, the planet carrier C _L of the first planetary gear mechanism 30L and the sun gear S _R of the second planetary gear mechanism 30R is coupled with the first coupling member 31, and the sun gear S _L of the first planetary gear mechanism 30L second a planet carrier C _R of the planetary gear mechanism 30R is coupled with the second coupling member 32.

The first coupling member 31, coupled with the planet carrier C _L of the first planetary gear mechanism 30L which torque TM2, which is generated by the electric motor 2L is engaged with the input gear 12a of the input gear shaft 12L via the idler gear 70a of the idler shaft 70L The torque TM1 generated by the electric motor 2R meshes with the input gear 12a of the input gear shaft 12R via the idler gear 70a of the idler shaft 70R. input is transmitted to the input-side external gear 13a that bind to the planet carrier C _R of the second planetary gear mechanism 30R. Further, the internal gear _RL of the first planetary gear mechanism 30L is connected to the left drive wheel 61L via a drive shaft including the output shaft 14L, constant velocity joints 65a and 65b, and an intermediate shaft 65c. The internal gear R _R of the second planetary gear mechanism 30R is connected to the right drive wheel 61R via a drive shaft comprising an output shaft 14R, constant velocity joints 65a and 65b, and an intermediate shaft 65c. In the third embodiment, deceleration is not performed on the output side after the gear unit 30.

  The gear device 30 is composed of a three-element and two-degree-of-freedom planetary gear mechanism that is coaxially combined with a pair of left and right intermediate gear shafts 13L and 13R.

As shown in the enlarged view of FIG. 13, the planetary gear mechanism constituting the gear device 30 includes internal gears R _L and R _R connected to the constant velocity joint 65a via output shafts 14L and 14R, an internal gear R _L , R _R and the sun gear S _L provided coaxially, S _R and internal gear R _L, R _R and the sun gear S _L, S plurality of duplicate planetary gear as revolving gear meshing with _R P _L, P _R is provided. The planetary gears P _L and P _R are supported by the planet carriers C _L and C _R. For planetary carriers C _L and C _R provided coaxially with the internal gears R _L and R _R , the first coupling member 31 that couples one planet carrier C _L and the other sun gear S _R, and one sun A second coupling member 32 that couples the gear S _L and the other planet carrier C _R is connected.

The planetary carriers C _L and C _R each include a carrier pin 33 that supports a plurality of planetary gears P _L and P _R , and a carrier flange 34a on the outboard side that is connected to the outboard side end of the carrier pin 33. And an inboard carrier flange 34b coupled to the inboard side end.

The inboard carrier flange 34b of the planetary carrier C _L includes a hollow shaft portion 36 extending toward the inboard side, and the second coupling member 32 and the first coupling member 31 are inserted into the hollow shaft portion 36. Further, on the outer periphery of the hollow shaft portion 36, an input side external gear 13a is provided that meshes with the input gear 12a of the input gear shaft 12L via an idler gear 70a.

Inboard carrier flange 34b of the planetary carrier C _R are formed integrally with the second coupling member 32, this on the outer periphery of the second coupling member 32, the input to mesh with the input gear 12a of the input gear shaft 12R through the idler gear 70a A side external gear 13a is provided. The inner circumference of the carrier flange 34a on the outboard side end portion of the planet carrier C _R is a first coupling member 31 is supported through a roller bearing 49.

The output shafts 14L and 14R coupled to the internal gears R _L and R _R are connected to the left and right drive wheels 61L and 61R via a drive shaft composed of constant velocity joints 65a and 65b and an intermediate shaft 65c. .

The sun gear S _L, S _R and the internal gear R _L, R _R are each plurality of duplicate planetary gears P _L, constitute a double-pinion planetary gear mechanism which meshes via a P _R.

The outer periphery of the end portion on the outboard side of the carrier flange 34a on the outboard side is supported by the internal gears R _L and R _R via rolling bearings 39a and 39a. The outer periphery of the end portion on the outboard side of the carrier flange 34b on the inboard side is supported by the internal gears R _L and R _R via rolling bearings 39b and 39b.

The inboard side end of the hollow shaft portion 36 of the inboard carrier flange 34b is supported through a rolling bearing 20a in a bearing fitting hole 19a formed in the partition wall 11 of the central housing 9a. In the embodiment shown in FIGS. 11 and 13, the carrier flange 34b on the inboard side of the planet carrier C _R are formed integrally with the second coupling member 32.

The plurality of double planetary gears P _L and P _R are supported by carrier pins 33 via needle roller bearings 37.

  The first coupling member 31 and the second coupling member 32 that couple the two planetary gear mechanisms that constitute the gear device 30 of the vehicle drive device 1 define the partition wall 11 that partitions the central housing 9a of the reduction gear housing 9 to the left and right. It is built through.

  The first coupling member 31 and the second coupling member 32 are arranged coaxially, and one coupling member (the second coupling member 32 in the embodiment of FIGS. 11 and 13) is a hollow shaft, and the other coupling member. (In the embodiment of FIGS. 11 and 13, the first coupling member 31) has a double structure including a shaft inserted through the hollow shaft.

In the embodiment shown in FIGS. 11 and 13, a spline is provided and an end portion of the left planetary gear mechanism 30L side of the first coupling member 31, the carrier flange 34a on the outboard side of the planet carrier C _L, the coupling member 31 is connected to the planet carrier C _L by spline fitting.

Further, in the embodiment shown in FIGS. 11 and 13, the end portion of the right side of the planetary gear mechanism 30R side of the second coupling member 32, and a hollow shaft portion 36 of the carrier flange 34b on the inboard side of the planet carrier C _R Although formed integrally, a spline is provided, the second coupling member 32 to the planet carrier C _R may be connected by a spline fitting. The outer peripheral surface of the inboard side of the carrier flange 34b of the planetary carrier C _R, the external gear is provided which meshes with idler gear 70a, the external gear forms the input-side external gear 13a

The outer peripheral surface of the inboard side of the carrier flange 34b of the planetary carrier C _L, the external gear is provided which meshes with idler gear 70a, the external gear forms the input-side external gear 13a.

The first coupling member 31 inserted through the second coupling member 32 constituted by a hollow shaft has a large-diameter portion 43 at an end portion on the right second planetary gear mechanism 30R side, and an outer periphery of the large-diameter portion 43. the surface, the external gear is formed to mesh with the planetary gears P _R of the planetary gear mechanism 30R, the external gear constitutes the sun gear S _R of the planetary gear mechanism 30R. The second coupling member 32, the outer peripheral surface of the end portion of the first planetary gear mechanism 30L side on the left side, the external gear is formed to mesh with the planetary gears P _L of the planetary gear mechanism 30L, the external gear of the planetary gear mechanism 30L The sun gear S _L is configured.

  The output shafts 14L and 14R are supported by rolling bearings 54b in bearing fitting holes 53b formed in the side housings 9bL and 9bR. And the bearing fitting hole 53b becomes a stepped shape with the wall part which the outer ring | wheel of the rolling bearing 54b contact | abuts.

  The output shafts 14L and 14R are pulled out of the reduction gear housing 9 from the openings formed in the side housings 9bL and 9bR, and the output shafts 14L and 14R are pulled out to the inner peripheral surface of the end portion on the outboard side. The outer joint portion of the speed joint 65a is splined.

  The constant velocity joint 65a coupled to the output shafts 14L and 14R is connected to the drive wheels 61L and 61R via the intermediate shaft 65c and the constant velocity joint 65b (FIG. 14).

  An oil seal 55 is provided between the end of the output shaft 14L, 14R on the outboard side and the opening formed in the side housings 9bL, 9bR, and leakage of the lubricating oil sealed in the reduction gear housing 9 and from the outside Prevents intrusion of muddy water.

  The third embodiment described above is an example in which the gear device 30 that is a torque difference amplification mechanism of the double pinion planetary gear mechanism is arranged on the second axis of the first stage reduction. The torque difference amplification factor is calculated by the same calculation as in the prior art 1 described above.

In the first and second embodiments described above, the reason why the method of arranging the gear device 30 on the third axis instead of the second axis is not preferable is as follows.
(1) Since the second shaft is a combination of a small gear and a large gear, the two gears are arranged in the axial direction and have a width, and there is little axial shortening effect by not arranging the gear device 30 on the second shaft.
(2) When the gear unit 30 is arranged on the third axis, it receives the increased torque after the two-stage deceleration, so the tooth width of the planetary gear mechanism of the torque difference amplifying mechanism is increased and the width of the torque difference amplifying mechanism is also increased. Become. Since the second gear is positioned so as to overlap the torque difference amplification mechanism in the axial direction, the axial shortening effect is further reduced.

  If the torque difference amplifying mechanism is arranged on the first axis, the planetary gear mechanism of the gear device rotates as a unit when the two electric motors have the same torque, and the large-diameter internal gear rotates at a high speed. High precision is required for the production of internal gears so that vibrations caused by unbalance do not occur. In combination with the above reason, the gear device 30 is preferably arranged on the second shaft (intermediate gear shaft) in the two-stage reduction.

  In the case where a reduction gear for reducing / increasing torque from the gear device 30 which is a torque difference amplifying mechanism to the driving wheel side is provided as shown in the second embodiment and a planetary gear mechanism is used for the reduction gear, the gear device When a gear (sun gear) that transmits torque from 30 to the next reduction gear is arranged on the inboard side from the previous input side external gear 13a, the first planetary gear mechanism 30L and the second planetary gear mechanism 30R are mirror-symmetrically arranged. Cannot be output coaxially to the reduction planetary gear mechanism, and must be output via gears (away from the motor shaft) to increase the overall size of the motor unit. This is not preferable because there is no axial shortening effect.

  The vehicle on which the vehicle drive device 1 is mounted is not limited to an electric vehicle or a hybrid electric vehicle, and may be, for example, a fuel cell vehicle using the first electric motor 2L and the second electric motor 2R as driving sources.

  The present invention is not limited to the above-described embodiments, and can be further implemented in various forms without departing from the gist of the present invention.

1: Vehicle drive device 2L, 2R: Electric motor 3L, 3R: Deceleration device 4L, 4R: Motor housing 4aL, 4aR: Motor housing body 4bL, 4bR: Outer wall 4cL, 4cR: Inner wall 5: Rotor 5a: Motor shaft 6 : Stator 8a, 8b, 17a, 17b, 20a, 20b, 39a, 39b, 54a, 54b, 72a, 72b, 86, 87: Rolling bearing 9: Reduction gear housing 9a: Central housing 9bL, 9bR: Side housing 9cL, 9cR : Reduction gear housing 11: Partition walls 12L and 12R: Input gear shaft 12a: Input gears 13L and 13R: Intermediate gear shafts 13a and 14b: Input side external gear 13b: Output side small gears 14L and 14R: Output shaft 14a: Output gear 16a, 16b, 19a, 19b, 53a, 53b, 71a, 71 : Bearing fitting holes 18, 88: seal member 30: gear device 30L: first planetary gear mechanism 30R: second planetary gear mechanism 31: first coupling member 32: second coupling members 33, 83: carrier pins 34a, 34b 84c, 84d: carrier flanges 35, 36: hollow shaft portions 37, 45, 46, 89: needle roller bearings 38: thrust plates 40, 44: collar 42: spline 43: large diameter portion 49: deep groove ball bearing 55: Oil seal 60: Chassis 61L: Left driving wheel 61R: Right driving wheel 62L: Left front wheel 62R: Right front wheel 63: Battery 64: Inverter 65a, 65b: Constant velocity joint 65c: Intermediate shaft 70L, 70R: Idler shaft 70a: Idler gear 80 : Planetary gear mechanisms 81L, 81R: Internal gears 82L, 82R: Planetary gear 84a: Inboard planet Yariya 84b: outboard side planet carrier _{P L, P R, 82L,} 82R: planetary gear _{R L,} R R: internal gear S _L, S _R, 85: sun gear C _L, C _R: planet carrier AM: electric vehicle M: Moment Zr, Zs: Number of teeth TM1, TM2: Motor torque TL, TR: Drive torque ΔTIN: Input torque difference ΔTOUT: Drive torque difference a, b: Distance α: Torque difference amplification factor

Claims (5)

  Two electric motors mounted on a vehicle and independently controllable, and a gear device provided between the two electric motors and the left and right drive wheels, and distributing torque from the two electric motors to the left and right wheels; And a reduction gear that transmits torque of the two electric motors to the drive wheels. The reduction gear is connected to the electric motor, an input gear shaft having an input gear, and an output connected to the drive wheels. At least one intermediate gear shaft that transmits power between the input gear shaft and the output shaft by meshing the shaft and the gear is provided, and the gear device that distributes torque from the two electric motors to the left and right wheels is coaxial. And an intermediate gear shaft to which torque is transmitted from the input gear and the input gear. An idler gear is provided between the large-diameter gear and the distance from the center of the motor shaft of the electric motor to the radial end of the stator of the electric motor, from the center of the motor shaft of the electric motor to the gear device. The vehicle drive device characterized in that the diameter of the idler gear is defined so that the distance becomes large.   The planetary gear mechanism of the gear device includes an internal gear, a planet carrier provided coaxially with the internal gear, a sun gear provided coaxially with the internal gear, and a planetary gear as a revolving gear. And a first coupling member that couples one planet carrier and the other sun gear of the two planetary gear mechanisms, and a second coupling member that couples one sun gear and the other planet carrier. The vehicle drive device according to claim 1. The planetary gear mechanism includes a sun gear, an internal gear provided coaxially with the sun gear, and a planet carrier provided coaxially with the sun gear,
The gear device includes a first coupling member that couples one planet carrier and the other sun gear, and a second coupling member that couples one sun gear and the other planet carrier,
The torque of one of the electric motors is transmitted to the first coupling member, the torque of the other electric motor is transmitted to the second coupling member, and one of the driving wheels receives torque from one internal gear. 2. The vehicle wheel drive device according to claim 1, wherein torque is transmitted to the other drive wheel from the other internal gear.   The gear constituting the speed reduction device is an external gear, an input side external gear meshing with the gear of the idler gear on an intermediate gear shaft of the speed reduction device coaxial with the gear device, a planet carrier of the planetary gear mechanism, 3. An output-side small-diameter gear that is connected and meshes with an output gear or a gear of a driven-side intermediate gear shaft is provided, and both ends of the planetary carrier are rotatably supported by rolling bearings. The vehicle drive device described.   Each of the planetary gear mechanisms has an internal gear, a planet carrier provided coaxially with the internal gear, a sun gear provided coaxially with the internal gear, and a planetary gear as a revolving gear, 5. The vehicle drive device according to claim 1, wherein an input side external gear that meshes with the idler gear is provided on an outer peripheral portion of the internal gear.

Images