WO2017141617A1 - Vehicle drive apparatus - Google Patents

Abstract

The present invention addresses the problem of making a torque-difference amplifying mechanism smaller and reducing a vehicle drive apparatus in size and weight. Planetary gear mechanisms 30L, 30R of a gear device 30, which distribute motive power of electric motors 2L, 2R to left and right wheels, respectively, are provided with internal gears R_L, R_R, planetary carriers C_L, C_R provided coaxially to the internal gears R_L, R_R, sun gears S_L, S_R provided coaxially to the internal gears R_L, R_R, and planetary gears P_L, P_R, respectively, and are provided with: a first coupling member 31 coupling the planetary carrier C_L on one side and the sun gear S_R on the other side; and a second coupling member 32 coupling the sun gear S_L on one side and the planetary carrier C_R on the other side, wherein input-side external gears 13a which are engaged with input gears 12a, and output-side small diameter gears 13b which are respectively connected to the planetary carriers C_L, C_R and which are engaged with output gears 14a, are provided to intermediate gear shafts 13L, 13R, external gears composing deceleration devices 3L, 3R are helical gears, and the internal gears R_L, R_R, the sun gears S_L, S_R, the planetary gears P_L, P_R composing the planetary gear mechanisms 30L, 30R are spur gears.

Description

Vehicle drive device

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

In a vehicle such as an electric vehicle, 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, thereby reducing the turning moment of the vehicle. 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.

Incidentally, 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 torque of the left and right electric motors transmitted to the left and right drive wheels is increased according to the reduction ratio of the reduction gear. 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 drive device disclosed in Patent Document 1 (hereinafter referred to as Conventional Technology 1) will be described with reference to FIGS. FIG. 6 is a skeleton diagram showing the gear configuration of the vehicle drive device according to the prior art 1, and FIG. 7 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.

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 and reduction gear trains 106L and 106R provided therebetween. 107L and 107R.

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 output shaft 102aL of the electric motor 102L and the output shaft 102aR of the electric motor 102R are connected to the coupling members 111 and 112 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 and 104R via the reduction gear trains 107L and 107R.

The gear unit 105 is configured by combining two identical planetary gear mechanisms 110L and 110R with 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. The single-pinion type planetary gear mechanism includes a sun gear S _L , S _R and internal gears R _L , R _R provided on the same axis, and these sun gears S _L , S _R and internal gears R _L , R _R. A plurality of planetary gears P _L and P _R and planetary gears P _L and P _R are rotatably supported, and are provided coaxially with the sun gears S _L and S _R and the internal gears R _L and R _R. It was planet carrier C _L, composed of a C _R. Here, the sun gear S _L, S _R and the planetary gears P _L, P _R is the external gear having gear teeth on the outer circumference, the internal gear R _L, R _R is the internal gear having gear teeth on the inner peripheral is there.

The planetary gears P _L and P _R are in 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 as shown in FIG. 6, 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 opposite directions. In the diagram, the internal gears R _L and R _R and the sun gears S _L and S _R are arranged on the opposite side with respect to the planetary carriers C _L and C _R. In other words, the internal gears R _L , R _R are arranged on the opposite side of the sun gears S _L , S _R across the planetary carriers C _L , C _R.

In the velocity diagram shown in FIG. 7, the ratio of the length from the planet carriers C _L , C _R to the internal gears R _L , R _R and the length from the planet carriers C _L , C _R to the sun gears S _L , 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. 6, the gear unit 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.

Then, the sun gear S _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 The sun gear S _R of the planetary gear mechanism 110R is coupled by the second coupling member 112.

The torque TM1 generated by the electric motor 102L is input to the first coupling member 111 via the reduction gear train 106L, and the torque TM2 generated by the electric motor 102R is input to the second coupling member 112 by the reduction gear train 106R. Is input through. Further, the planet carrier C _R of the planetary carrier C _L and the second planetary gear mechanism 110R of the first planetary gear mechanism 110L, respectively reduction gear train 107L, through 107R left and right drive wheels 104L, the output is connected to the 104R It is taken out.

Here, the driving torque transmitted by the gear device 105 will be described with reference to the 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 speed diagrams are shifted up and down, the speed diagram of the planetary gear mechanism 110L is shown on the upper side, and the speed diagram of the 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 and S _R and the internal gears R _L and R _R are arranged in the left and right directions. That is, in FIG. 7, the internal gear R _R of the second planetary gear mechanism 110R is arranged on the sun gear S _L of the first planetary gear mechanism 110L, the internal gear R _L of the first planetary gear mechanism 110L the sun gear S _R of the second planetary gear mechanism 110R is disposed underneath.

In the gear device 105, the elements located at both ends of the two velocity diagrams shown in FIG. 7 are coupled by the first coupling member 111 and the second coupling member 112, respectively, as indicated by broken lines in the drawing. . Then, the torques TM1 and TM2 output from the first electric motor 102L and the second electric motor 102R are input to the first connecting member 111 and the second connecting member 112, respectively. Here, originally, the torques TM1 and TM2 output from the electric motors 102L and 102R are input to the coupling members 111 and 112 via the reduction gear trains 106L and 106R, respectively. For the sake of simplicity, in the following explanation of the velocity diagram and each calculation formula, the reduction ratio is omitted, 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 planetary carriers C _L and C _R located in the middle on the velocity diagram shown in FIG. 7 to the left and right drive wheels 104L and 104R are output.

The gear device 105 configured in this manner gives a torque difference (input torque difference) ΔTIN (= TM2−TM1) to the drive torques TM1 and TM2 generated by the first electric motor 102L and the second electric motor 102R. Then, 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, since the two planetary gear mechanisms 110L and 110R are single pinion planetary gear mechanisms and use gear elements having the same number of teeth, the internal gear R _L and the planet carrier C _L are represented in the velocity diagram. 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 carrier C _L and the distance between the sun gear S _R and the planet carrier C _R are also equal, which is b.

Torques TM1 and TM2 of the first electric motor 102L and the second electric motor 102R are input to the first coupling member 111 and the second coupling member 112 at the left and right ends, respectively, and the driving torque TL is output from the planetary carriers C _L and C _R. When TR is taken out, the following equation (2) is obtained from the relationship between torque input and output.

TR + TL = TM1 + TM2 (2)

Also, the equation of moment with reference to the left end (R _L , S _R ) in the figure is the following equation (3). In FIG. 7, the arrow M direction indicates the positive moment direction.

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 expressed by the following equation (6).
(TL-TR) = ((a + b) / (ba)). (TM2-TM1) (6)

In the case of a single pinion type planetary gear mechanism, the length a is the reciprocal (1 / Zr) of the number of teeth Zr of the internal gears R _L and R _R , and the length b is the reciprocal of the number of teeth Zs of the sun gears S _L and S _R. Since (1 / Zs), the above equation can be rewritten as equation (7).
(TL-TR) = ((Zr + Zs) / (Zr-Zs)). (TM2-TM1) (7)

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

As described above, in the prior art 1, the inputs from the first electric motor 102L and the second electric motor 102R are S _L + R _R and S _R + R _L , and the outputs to the drive wheels 104L and 104R are C _L, the C _R.

When different torques TM1 and TM2 are generated by the two electric motors 102L and 102R to give an input torque difference ΔTIN (= (TM2−TM1)), the gear device 105 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 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)) 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. FIG. 8 is a skeleton diagram showing the gear configuration of the vehicle drive wheel device according to the prior art 2, and FIG. 9 is a velocity diagram for explaining the torque difference amplification factor by the vehicle drive device according to the prior art 2.

In FIG. 8, 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 to make the same figure as the prior art 1, and the same components are denoted by the same reference numerals. ing.

As shown in FIG. 8, the vehicle drive device 100 is provided between a first electric motor 102L and a second electric motor 102R mounted on the vehicle, a left drive wheel 104L and a right drive wheel 104R, and these. A gear device 105 and reduction gear trains 106L and 106R are provided.

The first electric motor 102L and the second electric motor 102R operate with electric power from a battery (not shown) mounted on the vehicle, and are individually controlled by an electronic control device (not shown) to generate different torques. Can be output. The output shaft 102aL of the first electric motor 102L and the output shaft 102aR of the second electric motor 102R are connected to the sun gears S _L and S _R of the gear device 105 via 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, a single pinion planetary gear mechanism is adopted.

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

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

Also, 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 outputs are taken out.

As described above, in the conventional technique 2, the inputs from the electric motors 102L and 102R are S _L and S _R , and the outputs to the drive wheels 104L and 104R are C _L + R _R and C _R + _RL .

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 is configured by combining two identical single pinion type 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 of the second planetary gear mechanism 110R is shown on the lower side. A diagram 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. 8, the planet carrier C _L and the internal gear R _R shown in FIG. 9 are coupled by the first coupling member 111 as shown by the broken line in the figure, and the planet carrier C _R and the internal gear R _L are combined. Are coupled by the second coupling member 112 as indicated by a broken line in the figure.

The 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.

Also with the gear device 105 configured in this way, a torque difference (input torque difference) ΔTIN (= TM2−TM1) is generated between the drive torques TM1 and TM2 generated by the first electric motor 102L and the second electric motor 102R. By giving, a driving torque difference ΔTOUT (= TR−TL) can be generated between the driving torque TL transmitted to the left driving wheel 104L and the driving torque TR transmitted to the right driving 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.

FIG. 9 shows the gear device 105 of the prior art 2 in a velocity diagram.

In this speed diagram, considering the torque balance, the torque difference gain α can be obtained. In FIG. 9, the arrow M direction indicates the positive moment direction.

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 this prior art 2, the inputs from the electric motors 102L, 102R are S _L , S _R , the outputs to the drive wheels 104L, 104R are C _L + R _R , C _R + _RL , 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, in the prior art 1 and the prior art 2, the torque difference is amplified by connecting the internal gears R _L and R _R constituting the two planetary gear mechanisms and the coupling member. One of the connecting members connecting the internal gears R _L and R _R to the other member necessarily has a larger diameter than the other internal gears R _L and R _R , so that there is a problem that the apparatus becomes large.

Since the vehicle drive device is mounted on the vehicle body, it is indispensable to reduce the size and weight of the gear device that amplifies the torque difference in order to reduce the mounting space and secure a wide cabin space.

When the input 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 drive force of the electric motor that matches the drive torque required for the drive wheel is obtained. Since this is necessary, the electric motor becomes large. 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 output shaft of the electric motor, the input gear shaft having a small diameter gear as an input gear, the output gear shaft having a large diameter gear as an output gear connected to a drive wheel, and the input gear shaft, At least one or more intermediate gear shafts that transmit power by engaging the gears between the output gear shafts are arranged.

In the prior art 1 and the prior art 2, the gear arrangement in the vehicle drive device is shown only in the skeleton diagram, but the applicant of the present application is smaller than the gear device that amplifies the torque difference between the prior art 1 and the prior art 2. A patent application has already been filed for a vehicle drive device that has been reduced in weight (Japanese Patent Application No. 2016-023529).

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

The vehicle drive device 201 of the first application example is provided between two electric motors 202L and 202R that are mounted on a vehicle and can be controlled independently, between the two electric motors 202L and 202R, and left and right drive wheels. A gear device 300 that distributes the driving force from the two electric motors 202L and 202R to the left and right wheels, and speed reducers 203L and 203R that transmit the driving force of the two electric motors 202L and 202R to the driving wheels are provided. 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 gear shafts 214L and 214R connected to driving wheels and having an output gear 214a, and gears. , And intermediate gear shafts 213L and 213R that transmit power between the input gear shafts 212L and 212R and the output gear shafts 214L and 214R, and the gears constituting the reduction gears 203L and 203R are external gears.

The gear device 300 that distributes the driving force from the two electric motors 202L and 202R to the left and right wheels is a three-element two-free combination that is coaxially combined with a pair of left and right intermediate gear shafts 213L and 213R. Planetary gear mechanisms 300L and 300R. Planetary gear mechanism 300L, 300R is an 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, and R _R solar provided coaxially gear S _L, and S _R, the planetary gear P _L as a revolving wheel, and a P _R, the two planetary gear mechanisms 300L, of one of the planet carrier C _L and the other 300R a first coupling member 231 for coupling the sun gear S _R, and a second coupling member 232 for coupling one of the sun gear S _L and the other planet carrier C _R, the gear 300 coaxial with certain intermediate gear shaft 213L, the 213R, provided 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 , The planetary carrier C _L , C Both ends of _R have a structure that is rotatably supported by a rolling bearing 219a, 219b with respect to a housing 209 that houses the gear device 300.

The vehicle driving device 201 is required to be quiet. For this reason, as shown in FIG. 12, external gears constituting the reduction gears 203L and 203R, that is, the output-side small gear 213b that meshes with the output gear 214a and the input-side external gear 213a that meshes with the input gear 212a, as shown in FIG. Gears are used. The output gear 214a that meshes with the output-side small-diameter gear 213b and the input gear 212a that meshes with the input-side external gear 213a are also helical gears.

Further, 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 in the planetary gear mechanisms 300L and 300R constituting the gear device 300 that amplifies the torque difference are also considered in terms of noise reduction. As shown in FIG. 12, a helical gear may be used.

However, considering the quietness, if helical gears are used for all gears, the helical gears generate a thrust force during rotation, so it is necessary to select bearings that also take the thrust force into consideration. Yes, the size of the unit is increased by the bearing size and the bearing support structure (axial dimension B shown in FIG. 12).

That is, as shown in FIG. 12, the rolling is provided between the thrust bearing 220a provided on both sides of the planetary gears P _L, P _R, and 220b, the internal gear R _L, R _R and planet carrier C _L, and C _R Both of the bearings 239a and 239b must be large in size.

The gear device 300 which is a torque difference amplifying mechanism has a planetary gear mechanism 300L having three types of gear elements (sun gears S _L and S _R , planetary gears P _L and P _R , and internal gears R _L and R _R ). Because two 300Rs are used, the number of constituent gears is large, and if all gears are manufactured with helical gears in consideration of noise reduction, the number of processing steps such as equipment adjustments according to the torsion angle increases. There is.

Therefore, according to the present invention, a small support bearing can be selected by combining a helical gear and a spur gear as a gear constituting the vehicle drive device, the unit can be reduced in size and cost, and the torque difference can be reduced. It is an object of the present invention to reduce the number of processing steps for gears in a planetary gear mechanism that constitutes a gear device that is an amplifying mechanism, and to reduce costs.

In order to solve the above-described problems, the present invention provides two drive sources mounted on a vehicle and independently controllable, and provided between the two drive sources and the left and right drive wheels. In a vehicle drive device comprising: a gear device that distributes power from a power source to left and right wheels; and a speed reducer that transmits power from the two drive sources to the drive wheels, the speed reducer is connected to the drive source and is input At least one input gear shaft having a gear, an output gear shaft connected to a drive wheel and having an output gear, and at least one intermediate gear shaft that transmits power between the input gear shaft and the output gear shaft by meshing of the gears The gear that constitutes the speed reduction device is an external gear, and the gear device that distributes the power from the two drive sources to the left and right wheels is coaxial with a pair of left and right intermediate gear shafts arranged coaxially. 3 elements 2 degrees of freedom planetary teeth The planetary gear mechanism comprises 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. An input side external gear meshing with an input gear or a drive side intermediate gear shaft and an planetary carrier of the planetary gear mechanism, and an output gear or An output-side small-diameter gear that meshes with the gear of the driven-side intermediate gear shaft is provided, and the external gear that constitutes the reduction gear is a helical gear, and the internal gear, the sun gear, and the planetary gear that constitute the planetary gear mechanism. Each spur gear It is characterized by that.

The input-side external gear that meshes with the input gear or the gear of the drive-side intermediate gear shaft can be integrally formed on the outer peripheral portion of the internal gear of the planetary gear mechanism.

The input side external gear that meshes with the input gear or the gear on the drive side intermediate gear shaft may be formed by a member separate from the internal gear of the planetary gear mechanism.

The internal gear of the planetary gear mechanism can be rotatably supported by a rolling bearing with respect to the planet carrier.

The speed reducer housing of the vehicle drive device has a three-piece configuration including a central housing and left and right side housings. A partition wall is provided at the central portion of the central housing to partition the left and right, and the first coupling of the gear device A member and the second coupling member may be provided so as to penetrate the partition wall.

The oil supply hole can be provided in the inner diameter of the inner diameter side of the first coupling member and the second coupling member.

In this invention, the sun gear, planetary gear, and internal gear in the planetary gear mechanism of the torque difference amplifying mechanism are spur gears, but the gear of the reduction gear used in combination with the torque difference amplifying mechanism always rotates during traveling. Since there is a possibility that sound may be generated due to the meshing between the gears, a helical gear with good noise reduction is used.

Then, the sun gear, planetary gear, and internal gear constituting the planetary gear mechanism are spur gears, so that the thrust force during rotation is not generated and the bearing is downsized and the support structure is simplified. In addition, by using a spur gear, it is not necessary to set up in accordance with the torsion angle when processing a helical gear, and the number of processing steps can be reduced.

When this invention is used as a left and right wheel drive device, the planetary gear mechanism of the torque difference amplifying mechanism is integrated with the planetary gear mechanism as a whole when there is no difference in torque and rotational speed between the left and right wheels as when traveling straight. In this invention, a spur gear is used instead of a helical gear because no rotation difference occurs between the sun gear, the planetary gear, and the internal gear, and no sound is generated by meshing between the gears. It was.

Even if a spur gear is used for the planetary gear mechanism of the torque difference amplifying mechanism, the torque difference amplifying mechanism mainly causes left and right torque differences and rotational speed differences during turning that is less frequent than straight running. Occasionally, the difference in rotation between the gears in the planetary gear mechanism is little, so the influence on the quietness of the vehicle is small.

Therefore, in this invention, the sun gear, planetary gear, and internal gear in the planetary gear mechanism of the torque difference amplification mechanism are spur gears, and the gear of the reduction gear used in combination with the torque difference amplification mechanism always rotates during traveling. Since there is a possibility that sound may be generated due to the meshing between the gears, a helical gear with good noise reduction is used.

Furthermore, in the present invention, the connection between the two planetary gear mechanisms of the gear device that is the torque difference amplifying mechanism is a connection between the sun gear and the planet carrier, and a connecting member having a larger diameter than the internal gear is not required. The difference amplifying mechanism can be reduced, and the vehicle drive device including the torque difference amplifying mechanism can be reduced in size and weight.

¡By providing the gear device, which is a torque difference amplifying mechanism, coaxially with the pair of intermediate gear shafts of the vehicle drive device, the gear device itself does not greatly increase in diameter.

In addition, the two planetary gear mechanisms are coupled by a first coupling member and a second coupling member having a double structure comprising a hollow shaft and a shaft inserted into the hollow shaft, and are connected to the inner diameter side of the inner diameter side coupling member. By providing the oil supply hole, the shaft center oil supply can be performed, so that the gear tooth surface and the bearing portion inside the planetary gear mechanism can be easily lubricated.

Further reduction in size can be achieved by integrally forming the internal gear of the planetary gear mechanism and the input side external gear and providing the input side external gear on the outer peripheral portion of the internal gear.

Furthermore, the rotation accuracy of the gear shaft can be ensured by supporting both ends of the planetary carrier of the gear device with rolling bearings and supporting the internal gear with the rolling bearings with respect to the planetary carrier.

It is a cross-sectional top view which shows embodiment of the vehicle drive device of this invention. It is an enlarged view of the gear apparatus part of embodiment of FIG. It is the fragmentary sectional view which showed a part of gear of the gear apparatus of embodiment of FIG. 1 with the external shape. 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 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. It is an enlarged view of the gear apparatus part of the vehicle drive device of prior application example 1 shown in FIG. It is the fragmentary sectional view which showed a part of gear of the gear apparatus of the prior application example 1 shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

The electric vehicle AM shown in FIG. 4 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. 4, the gear structure of the vehicle drive device 1 is shown with the skeleton figure.

A vehicle drive device 1 shown in FIG. 1 drives a pair of left and right drive wheels. The motors 2L and 2R serve as two drive sources that are mounted on the vehicle and can be controlled independently, and left and right drive wheels 61L. , 61R and two electric motors 2L, 2R, two left and right reduction gears 3L, 3R are provided.

The driving 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.

In addition, as a mounting form of the two-motor type vehicle driving device 1, in addition to the rear wheel driving method shown in FIG. 4, a front wheel driving method and a four wheel driving method 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 accommodated in motor housings 4L and 4R as shown in FIG.

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 reduction gears on the inner surfaces of the motor housing bodies 4aL and 4aR. It consists of inner walls 4cL and 4cR separated from 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 7 is provided between the openings of the inner side walls 4cL and 4cR of the motor housing bodies 4aL and 4aR and the motor shaft 5a.

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).

A plurality of bolts 10 are used to fix side faces 9bL and 9bR of the reduction gear housing 9 on the side of 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 Thus, the two electric motors 2L and 2R are fixedly arranged on the left and right sides of the reduction gear housing 9 (FIG. 1).

As shown in FIG. 1, the central housing 9a is provided with a partition wall 11 in 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 and 3R are provided symmetrically, and input gear shafts 12L and 12R having an input gear 12a connected to the motor shaft 5a and a large-diameter input engaged with the input gear 12a. The intermediate gear shafts 13L and 13R having output side small-diameter gears 13b meshing with the side outer gear 13a and the output gear 14a, and the output gear 14a, are pulled out from the speed reducer housing 9 and are constant velocity joints 65a and 65b, and an intermediate shaft 65c. This is a parallel shaft gear reducer provided with output gear shafts 14L, 14R that transmit torque to drive wheels 61L, 61R via (FIG. 4). The input gear shafts 12L and 12R, the intermediate gear shafts 13L and 13R, and the output gear 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 end portions on the outboard side of the input gear shafts 12L, 12R are drawn outward from the openings provided in the side housings 9bL, 9bR, and between the openings and the outer ends of the input gear shafts 12L, 12R. Is provided with an oil seal 18 to prevent leakage of the lubricating oil sealed in the speed reducer housing 9.

The input gear shafts 12L and 12R have a hollow structure, and end portions of the motor shaft 5a are inserted into the hollow input gear shafts 12L and 12R. The input gear shafts 12L, 12R and the motor shaft 5a are connected by splines (including the same for serrations).

At least one or more 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 meshed with the input gear 12a and an output side small diameter gear 13b meshed with the output gear 14a on the outer peripheral surface. At both ends of the intermediate gear shafts 13L and 13R, rolling bearings 20a and 20b are fitted 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. Is supported through. And the bearing fitting holes 19a and 19b have a stepped shape with a wall portion with which the outer rings of the rolling bearings 20a and 20b abut so that a first coupling member 31 and a second coupling member 32 to be described later pass. It penetrates.

The intermediate gear shafts 13L and 13R arranged on the same axis are connected to the intermediate gear shafts 13L and 13R so that the drive torque applied from the two electric motors 2L and 2R is a torque difference between the left and right drive wheels 61L and 61R. A gear device 30 for amplifying and distributing the signal is incorporated.

The gear unit 30 is composed of a pair of left and right intermediate gear shafts 13L and 13R arranged on the same axis and two planetary gear mechanisms 30L and 30R with two elements on the same axis.

As shown in the enlarged view of FIG. 2, the planetary gear mechanisms 30L and 30R constituting the gear device 30 have internal gears R _L and R incorporated in the large-diameter input side external gear 13a of the intermediate gear shafts 13L and 13R, respectively. and _R, the 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 as revolving gear meshing with S _{R L,} and P _R, the planetary gear P _L, is connected to the P _R, the internal gear R _L, R _R and planet carrier C _L provided coaxially, and C _R, the one planet carrier C _L (FIG. 2 The first coupling member 31 that couples the left side of the figure) and the other sun gear S _R (right side of the figure in FIG. 2), one sun gear S _L (left side of the figure in FIG. 2), and the other planet carrier C a second coupling member 32 for coupling the _R (in FIG. 2 FIG right), the internal gear R _L, linked to R _R, the input gear shaft An input side external gear 13a that meshes with the input gear 12a of 2L, 12R, and an output side small gear 13b of the intermediate gear shafts 13L, 13R that meshes with the output gear 14a of the output gear shafts 14L, 14R. The output side small-diameter gear 13b of 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 planetary gear mechanisms 30L and 30R constituting the gear device 30 are incorporated only in any one of the pair of intermediate gear shafts 13L and 13R. The input side external gear 13a connected to the internal gears R _L , R _R is a gear provided on the drive side intermediate gear shafts 13L, 13R of the plural pairs of intermediate gear shafts 13L, 13R, or the input gear shaft 12L. The output side small gear 13b provided coaxially with the planetary gear mechanisms 30L and 30R is provided on the driven side of the plurality of pairs of intermediate gear shafts 13L and 13R. It arrange | positions so that it may mesh with the gear provided in the intermediate gear shafts 13L and 13R, or the output gear 14a of the output gear shafts 14L and 14R.

In the embodiment shown in FIG. 1, the internal gear R _L, R _R in connected input-side external gear 13a is an internal gear R _L, but are formed integrally with the R _R, it may be formed separately .

Further, in the embodiment shown in FIG. 1, the planet carrier C _L, the output-side small-diameter gear 13b which is connected to the C _R is the planet carrier C _L, although formed integrally with the C _R, and formed separately Also good.

Planet carrier C _L, C _R is the planetary gears P _L as shown in FIG. 2, P a carrier pin 33 which supports the _R, carrier flange 34a on the outboard side end portion linked outboard side of the carrier pin 33 And an inboard carrier flange 34b coupled to the inboard side end.

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 FIG. 1, 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.

Further, 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 30L and 30R constituting the gear device 30 of the vehicle drive device 1 are partitions that partition the central housing 9a of the reduction gear housing 9 to the left and right. It penetrates through the wall 11 and is incorporated.

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 2) is a hollow shaft and the other coupling member. (In the embodiment of FIGS. 1 and 2, 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 2, the end portion of the right side of the planetary gear mechanism 30R side in 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 the spline 41 is provided on the part 36, are connected by spline fitting to the second coupling member 32 the planet carrier C _R.

Further, in the embodiment shown in FIGS. 1 and 2, 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.

As described above, the two planetary gear mechanisms 30L, first coupling member 31 of the 30R and a second binding member 32, by connecting the splined to the planet carrier C _L and the planet carrier C _R, two The planetary gear mechanism can be divided into left and right, and can be incorporated into the three-piece reduction gear housing 9 together with other reduction gear shafts from the left and right.

End of the planet carrier C _L of the second coupling member 32 has, on its outer peripheral surface, the external gear meshing with the planetary gears P _L of the left planetary gear mechanism is formed, the sun the external gear of the left planetary gear mechanism A gear S _L is configured.

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 planetary gear mechanism 30R side, and an outer peripheral surface of the large diameter portion 43 is provided. , external gear meshing with the planetary gears P _R of the right planetary gear mechanism 30R is formed, the outer gear constitutes the sun gear S _R of the right planetary gear mechanism 30R.

Of the first coupling member 31 and second coupling member 32, the maximum diameter of the sun gear S _R are connected to the inner diameter side of the coupling member (first coupling member 31), the binding of the outer diameter side member (the second coupling by member 32) is set smaller than the minimum diameter of the spline hole of the inner surface of the hollow shaft portion 36 of the carrier flange 34b on the inboard side of the planet carrier C _R for mating, the inner diameter side of the coupling member (first coupling member 31 ) Can be easily incorporated.

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 first coupling member 31 and the second coupling member 32 and the planetary carriers C _L and C _R are fitted to the planetary carriers C _L and C _R (splines 42 and 41) by using a fitting tolerance slidable in the axial direction. Uneven load on the gear tooth surface due to the thrust force can be prevented.

Further, the axial movement of the first coupling member 31 and the second coupling member 32 and the planetary carriers C _L and C _R due to the sliding of the spline (splines 42 and 41) fitting portion is caused by the outer diameter side coupling member (FIG. 1). In the embodiment of FIG. 2, the second coupling member 32) is regulated by providing thrust bearings 47 and 48 at both ends.

The coupling member (the first coupling member 31 in the embodiment of FIGS. 1 and 2) on the inner diameter side of the double-structure shaft that couples the two planetary gear mechanisms 30L and 30R is the coupling member (implementation of FIGS. 1 and 2). In the form, the shaft end opposite to the spline fitting between the first coupling member 31) and the planet carrier (C _{L in the} embodiment of FIGS. 1 and 2) is connected to the other planet carrier (the embodiment of FIGS. 1 and 2). In this case, C _R ) is supported by a deep groove ball bearing 49.

The coupling member (the first coupling member 31 in the embodiment shown in FIGS. 1 and 2) on the inner diameter side of the double-structure shaft that couples the two planetary gear mechanisms 30L and 30R has teeth of the sun gears S _L and S _R. surface, the planetary gear P _L, the tooth surfaces of the P _R, in order to supply the lubricating oil, etc, is provided an oil supply hole 50 to the axis. The oil supply hole 50 of the inner diameter side coupling member (first coupling member 31 in the embodiment of FIGS. 1 and 2) has an outer diameter side coupling member (second coupling member 32 in the embodiment of FIGS. 1 and 2). Radial oil supply passages 51 and 52 are provided at the positions of the thrust bearings 47 and 48 at both ends.

The output gear shafts 14L and 14R have a large-diameter output gear 14a, and are formed in bearing fitting holes 53a formed on both surfaces of the partition wall 11 of the central housing 9a and bearing fitting holes 53b formed on the side housings 9bL and 9bR. It is 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 side ends of the output gear 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 outboard side of the output gear shafts 14L and 14R. The outer joint portion of the constant velocity joint 65a is splined to the outer peripheral surface of the end portion.

The constant velocity joint 65a coupled to the output gear 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. 4).

An oil seal 55 is provided between the end of the output gear shafts 14L and 14R on the outboard side and the opening formed in the side housings 9bL and 9bR, and leakage of the lubricating oil sealed in the speed reducer housing 9 and the outside Intrusion of muddy water from

Next, in the present invention, as shown in FIG. 3, the sun gears S _L and S _R , the planetary gears P _L and P _R , the internal gears R _L and R in the planetary gear mechanisms 30L and 30R of the torque difference amplification mechanism. All _R are spur gears.

Since the gears constituting the reduction gears 3L and 3R used in combination with the torque difference amplification mechanism may generate noise due to the meshing between the rotating gears during traveling, the noise reduction is good. Uses helical gears.

Specifically, an input-side external gear 13a that meshes with an input gear 12a that is a component of the reduction gears 3L and 3R, and an output-side small-diameter gear 13b that meshes with an output gear 14a, as shown in FIG. It is composed by. The input gear 12a meshing with the input-side external gear 13a and the output gear 14a meshing with the output-side small-diameter gear 13b are also constituted by helical gears.

If the sun gears S _L , S _R , the planet gears P _L , P _R , and the internal gears R _L , R _R in the planetary gear mechanisms 30L, 30R of the torque difference amplifying mechanism are constituted by spur gears, a lotus shown in FIG. As in the case of using gears, since no thrust force is generated during rotation, the bearing size and the bearing support structure can be reduced, leading to a reduction in the size of the unit.

That can be used planetary gears P _L, a thrust bearing 220a of Fig. 12 a thrust member provided on both sides of the P _R, a thin thrust plate 38 in place of the 220b, also internal gear R _L, R _R and planet carrier C _L , the rolling bearing 239a in FIG. 12 a rolling bearing provided between the C _R, the rolling bearing 39a of smaller size than 239b, so 39b can be used, the axial dimension of the gear device 30 (a in Figure 3), It can be made smaller than the axial dimension (B in FIG. 12) of the gear device 300 in FIG. 12 (A <B).

Further, by using a spur gear as the sun gears S _L , S _R , the planet gears P _L , P _R , and the internal gears R _L , R _R in the planetary gear mechanisms 30L, 30R, the torsion at the time of processing the helical gears It is not necessary to set up according to the corner, and the number of processing steps can be reduced.

The planetary gear mechanisms 30L and 30R of the torque difference amplifying mechanism are rotated as a whole when the planetary gear mechanisms 30L and 30R are united when there is no difference in torque and rotational speed between the left and right wheels as in straight travel. , The sun gears S _L , S _R , the planetary gears P _L , P _R , the internal gears R _L , R _R do not produce a rotation difference, and no noise is generated by meshing between the gears. , 30R is not a helical gear but a spur gear.

Even if spur gears are used for the planetary gear mechanisms 30L and 30R of the torque difference amplifying mechanism, the torque difference amplifying mechanism mainly causes left and right torque differences and rotational speed differences. The difference in rotation between the gears in the planetary gear mechanisms 30L and 30R during the turn is small, so the influence on the quietness of the vehicle is small.

As described above, in the present invention, the sun gears S _L and S _R , the planet gears P _L and P _R , and the internal gears R _L and R _R in the planetary gear mechanisms 30L and 30R of the torque difference amplification mechanism are spur gears, Since the gear elements of the reduction gears 3L and 3R used in combination with the torque difference amplifying mechanism may generate a sound due to the meshing between the rotating gears during traveling, a helical gear with good quietness Is used.

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

As shown in FIG. 4, 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 torque of the motor shaft 5a of the electric motors 2L and 2R is the gear ratio between the input gear shaft 12a of the input gear shafts 12L and 12R of the reduction gears 3L and 3R and the large-diameter input side external gear 13a of the intermediate gear shafts 13L and 13R. And transmitted to the internal gears R _L and R _R of the gear device 30.

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 gear shafts 14L and 14R via the gear device 30, and the number of teeth of the output side small gear 13b and the output gear 14a. The torque of the motor shafts 5a of the electric motors 2L and 2R is further increased by the ratio and output to the drive wheels 61L and 61R.

The gear device 30 is configured by combining two planetary gear mechanisms 30L and 30R having the same three-element and two-degree-of-freedom with coaxial intermediate gear shafts 13L and 13R. The planetary gear mechanisms 30L and 30R are of a single pinion type. A planetary gear mechanism is used.

The planetary gear mechanisms 30L and 30R are coaxially provided with sun gears S _L and S _R and internal gears R _L and R _R, and between these sun gears S _L and S _R and the internal gears R _L and R _R. a plurality of planetary gears P _L, P _R is close to the planetary gear P _L, provided the P _R rotatably supported by the sun gear S _L, S _R and the internal gear R _L, on R _R coaxial It is composed of planetary carriers C _L and C _R. Here, the sun gear S _L, S _R and the planetary gears P _L, P _R is the external gear having gear teeth on the outer circumference, the internal gear R _L, R _R is the internal gear having gear teeth on the inner peripheral is there. 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 planetary gear mechanisms 30L, 30R, when the planet carriers C _L , C _R are fixed, the sun gears S _L , S _R and the internal gears R _L , R _R rotate in opposite directions, so the speed line shown in FIG. In the figure, the internal gears R _L and R _R and the sun gears S _L and S _R are arranged on the opposite side to the planetary carriers C _L and 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 planet gear P _L and the internal gear _RL , and 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, coupled with 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 form a first coupling member 31, the sun of the first planetary gear mechanism 30L a planet carrier C _R gear S _L and the second planetary gear mechanism 30R form a second coupling member 32 are coupled.

The torque TM1 generated by the electric motor 2L is transmitted to the intermediate gear shaft 13L when the input gear 12a of the input gear shaft 12L and the input side external gear 13a are meshed, and the torque transmitted to the intermediate gear shaft 13L is the first torque. It is transmitted to the output-side small gear 13b of the intermediate gear shaft 13L via the planetary gear mechanism 30L, and the output-side small gear 13b of the intermediate gear shaft 13L and the output gear 14a of the output gear shaft 14L are meshed to drive from the output gear shaft 14L. A driving torque TL is output to the wheel 61L.

The torque TM2 generated by the electric motor 2R is transmitted to the intermediate gear shaft 13R when the input gear 12a of the input gear shaft 12R and the input side external gear 13a are meshed, and the torque transmitted to the intermediate gear shaft 13R is the second torque. It is transmitted to the output-side small gear 13b of the intermediate gear shaft 13R via the planetary gear mechanism 30R, and the output-side small gear 13b of the intermediate gear shaft 13R and the output gear 14a of the output gear shaft 14R are meshed to drive from the output gear shaft 14R. A driving torque TR is output to the wheel 61R.

Electric motor 2L, the output from the 2R, the two planetary gear mechanisms 30L, each of the internal gear R _L of 30R, given R _R, the first coupling member 31, the output from the second coupling member 32 is the driving wheel 61L , 61R.

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, which is a solid shaft, has one end (right end in the drawing) serving as the rotation shaft of the sun gear S _R , and the other end (left end in the drawing) penetrating the sun gear S _L. It is connected to the carrier C _L. 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. The first planetary gear mechanisms 30L and 30R are coupled by the first coupling member 31 and the second coupling member 32.

Incidentally, the gear device 30 is configured by combining two identical single pinion planetary gear mechanisms 30L and 30R, and therefore 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. Originally, in the embodiment of FIG. 1, the torques TM1 and TM2 output from the electric motors 2L and 2R are respectively transmitted through the input side external gears 13a meshing with the input gears 12a of the input gear shafts 12L and 12R. Since the gears R _L and R _R are input to the transmission gear, a reduction ratio is applied. The drive torques TL and TR taken out from the gear device 30 are connected to the left and right drive wheels 61L via the output-side small-diameter gear 13b meshing with the output gear 14a. However, in order to facilitate understanding, the speed ratio and the calculation formulas shown in FIG. 5 are omitted in the following description of the speed ratio and the calculation formulas, and the internal gears R _L , R are omitted. _The torque input to _R remains TM1 and TM2, and the drive torque remains TL and TR.

Since the two planetary gear mechanisms 30L and 30R constituting the gear device 30 use gear elements having the same number of teeth, the distance between the internal gear R _L and the planet carrier C _L and the internal gear in the speed diagram. 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 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 based on the point of R _R. In FIG. 5, the arrow M direction in the figure is the positive moment direction.
a · TR + (a + b) · TL− (b + 2a) · TM1 = 0 (11)

The following equation (12) is calculated from the balance of moment M with reference to point R _L.
-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 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 electric motor 2L, input from 2R is, R _L, R _R, and the drive wheels 61L, the output of the 61R becomes _{S R + C L, S L} + C R.

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 A driving torque difference α · ΔTIN larger than 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)) larger than the input torque difference ΔTIN can be given to the driving torques TL and TR transmitted to 61R.

In the prior art 1 and the prior art 2, since the internal gear R is included in the left and right connecting members of the two planetary gear mechanisms of the gear device 105 that is the torque difference amplifying mechanism, the coupling that connects either the left or right internal gear and another member. One of the members must have a larger diameter than the other internal gear R.

In the present invention, the connection between the two planetary gear mechanisms 30L and 30R constituting the gear device 30 that is the torque difference distribution mechanism is the sun gear S _R and the planet carrier C _L , and the sun gear S _L and the planet carrier C _R. No connection member having a larger diameter than the internal gears R _L and R _R is required. For this reason, in this invention, since the torque difference distribution mechanism can be made smaller than those of the prior art 1 and the prior art 2, the vehicle drive device 1 for an electric vehicle incorporating the torque difference distribution mechanism is made smaller and lighter. Can be

¡By reducing the size and weight of the vehicle drive device 1 for an electric vehicle, the degree of freedom of the vehicle body mount layout of peripheral accessories is improved along with the vehicle body mount layout of the vehicle drive device 1.

In addition, there is a merit that the vehicle interior space is expanded by reducing the size of the vehicle drive device 1.

1 exemplifies the case where the electric motors 2L and 2R are used as the two drive sources and the electric motors have the same output characteristics, but the two drive sources are not limited thereto.

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 that uses the first electric motor 2L and the second electric motor 2R as driving sources. Good.

The present invention is not limited to the embodiment described above, and can be 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 7: Sealing members 8a and 8b: Rolling bearing 9: Reduction gear housing 9a: Central housing 9bL and 9bR: Side housing 10: Bolt 11: Partition walls 12L and 12R: Input gear shaft 12a: Input gear shafts 13L and 13R: Intermediate Gear shaft 13a: Input side external gear 13b: Output side small diameter gears 14L, 14R: Output gear shaft 14a: Output gears 16a, 16b: Bearing fitting holes 17a, 17b: Rolling bearing 18: Oil seals 19a, 19b: Bearing fitting Hole 20a, 20b: Rolling bearing 30 : Gear units 30L, 30R: planetary gear mechanism 31: first coupling member 32: second coupling member 33: carrier pins 34a, 34b: carrier flanges 35, 36: hollow shaft portion 37: bearing 38: thrust plates 39a, 39b: Rolling bearing 40: Collar 41, 42: Spline 43: Large diameter portion 44: Collar 45, 46: Bearing 47, 48: Thrust bearing 49: Deep groove ball bearing 50: Oil hole 51, 52: Oil passage 53a, 53b: Bearing fit Joint hole 54a, 54b: Rolling bearing 55: Oil seal 60: Chassis 61L, 61R: Drive wheel 62L, 62R: Front wheel 63: Battery 64: Inverter 65a, 65b: Constant velocity joint 65c: Intermediate shaft AM: Electric vehicle C _L , C _R : Planetary carrier P _L , P _R : Planetary gear R _L , R _R : Internal gear S _L , S _R : Sun gear TM1, TM2: Torque TL, TR: Drive torque Zr: Number of teeth Zs of internal gears R _L , R _R : Number of teeth α of sun gears S _L , S _R : Torque difference gain

Claims (6)

1. Two drive sources mounted on the vehicle and independently controllable, and a gear device provided between the two drive sources and the left and right drive wheels, and distributing power from the two drive sources to the left and right wheels And a reduction gear that transmits power of the two drive sources to the drive wheels. The reduction gear is connected to the drive source, and is connected to an input gear shaft having an input gear, and to the drive wheels. An output gear shaft having an output gear and at least one intermediate gear shaft for transmitting power between the input gear shaft and the output gear shaft by meshing of the gears, and the gear constituting the reduction gear is an external gear The gear device for distributing the power from the two drive sources to the left and right wheels is a three-element, two-degree-of-freedom planetary gear that is coaxially combined with a pair of left and right intermediate gear shafts arranged coaxially. The planetary gear mechanism is an internal gear A planetary carrier provided coaxially with the internal gear, a sun gear provided coaxially with the internal gear, and a planetary gear serving as a revolving gear, and one of the two planetary gear mechanisms. The speed reducer having a first coupling member for coupling the planet carrier and the other sun gear, and a second coupling member for coupling one sun gear to the other planet carrier, and coaxial with the gear device The intermediate gear shaft is connected to the input side external gear that meshes with the gear of the input gear or the drive side intermediate gear shaft, and the planetary carrier of the planetary gear mechanism, and the output side small diameter that meshes with the gear of the output gear or the driven side intermediate gear shaft. A vehicle drive characterized in that the external gear constituting the reduction gear is a helical gear, and the internal gear, the sun gear, and the planetary gear constituting the planetary gear mechanism are respectively spur gears. apparatus.
2. 2. The vehicle drive device according to claim 1, wherein an input-side external gear that meshes with the input gear or the gear of the drive-side intermediate gear shaft is integrally formed on an outer peripheral portion of the internal gear of the planetary gear mechanism. .
3. The input side external gear meshing with the gear of the input gear or the drive side intermediate gear shaft and the internal gear of the planetary gear mechanism are formed by separate members on the intermediate gear shaft of the reduction mechanism that is coaxial with the gear device. The vehicle drive device according to claim 1, wherein
4. The vehicle drive device according to any one of claims 1 to 3, wherein the internal gear of the planetary gear mechanism is rotatably supported by a rolling bearing with respect to the planet carrier.
5. The speed reducer housing of the vehicle drive device has a three-piece configuration including a central housing and left and right side housings. A partition wall is provided at the central portion of the central housing to partition the left and right, and the first coupling member and the first housing The vehicle drive device according to any one of claims 1 to 4, wherein two connecting members pass through the partition wall.
6. The vehicle drive device according to any one of claims 1 to 5, wherein an oil supply hole is provided in an inner diameter of a coupling member on an inner diameter side of the first and second coupling members.

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