JP6170580B1 - Vehicle drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve stability of vehicle behavior by equalizing torque responsiveness of left and right wheels in a vehicle drive device provided with a gear device 30 for amplifying a torque difference from two electric motors 2L and 2R to left and right drive wheels. Let SOLUTION: Two planetary gear mechanisms are coaxially combined between two electric motors 2L, 2R that are mounted on a vehicle and can be controlled independently, and left and right drive wheels, and a specific one of the planetary gear mechanisms is specified. The element and the specific element of the other planetary gear mechanism are connected to each other by the first coupling member 31 and the second coupling member 32 to amplify the torque difference from the two electric motors 2L, 2R to the left and right drive wheels. In the vehicle drive device provided with the gear device 30, the same torque is input to the first coupling member 31 and the second coupling member 32 from the electric motors 2 </ b> L and 2 </ b> R as the shape and dimensions of the first coupling member 31 and the second coupling member 32. In this case, the torsion angles of the first coupling member 31 and the second coupling member 32 are set to be equal, and the torque responsiveness of the left and right wheels is made equal. [Selection] Figure 2

Description

  The present invention relates to a vehicle drive device that can transmit drive torque from two independent drive sources to the left and right drive wheels by amplifying the torque difference, and in particular, the left and right wheels have the same torque responsiveness and the vehicle behavior. The present invention relates to a vehicle drive device with improved stability.

  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.

  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 drive device disclosed in Patent Document 1 (hereinafter referred to as Conventional Technology 1) will be described with reference to FIGS. FIG. 7 is a skeleton diagram showing the gear configuration of the vehicle drive device according to the prior art 1. FIG. 8 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 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 and 104R via the reduction gear trains 107L and 107R.

  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 single pinion planetary gear mechanism is adopted. The single pinion planetary gear mechanism includes a sun gear S _L , S _R and an internal gear R _L , R _R provided on the same axis, and between these sun gears S _L , S _R and the 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 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 single pinion planetary gear mechanism as shown in FIG. 7, 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, so that the speed 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. 8, 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. 7, the 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 , 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 a velocity diagram shown in FIG.

  Since the gear unit 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. 8, 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 this gear device 105, elements located at both ends of the two velocity diagrams shown in FIG. 8 are coupled by a first coupling member 111 and a second coupling member 112, respectively, as indicated by broken lines in the figure. . Then, torques TM1 and TM2 output from the first 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, driving torques TL and TR transmitted from the planetary carriers C _L and C _R located in the middle of the velocity diagram shown in FIG. 8 to the left and right driving 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. 8, the arrow M direction indicates the + 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 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 equation (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. 9 is a skeleton diagram showing the gear configuration of the vehicle drive wheel device according to the prior art 2. FIG. 10 is a velocity diagram for explaining the torque difference amplification factor by the vehicle drive device according to the prior art 2.

  In FIG. 9, in order to make the difference from the prior art 1 easier to understand, electric motors 102L and 102R are arranged on the left and right to make the same figure as in the prior art 1, and the same components are denoted by the same reference numerals. ing.

  As shown in FIG. 9, 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.

  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.

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 planetary gear mechanisms 110L and 110R, the gear device 105 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. 9, the planet carrier C _L and an internal gear R _R shown in FIG. 10, as indicated by the broken line in the figure, are coupled by a first coupling member 111, the planet carrier C _R and the internal gear R _L 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 manner, 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. 10 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 FIG. 10, the arrow M direction indicates the + 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 said prior art 1 and the prior art 2, the specific element of one planetary gear mechanism and the specific element of the other planetary gear mechanism are mutually connected by the 1st coupling member and the 2nd coupling member. The torque difference is amplified.

  The first coupling member and the second coupling member that couple the two planetary gear mechanisms connect the other coupling member (for example, the second coupling member) while avoiding one coupling member (for example, the first coupling member). Therefore, both cannot have the same structure.

  For example, in the prior art 1, the shaft passing between the two planetary gear mechanisms has a double structure.

  Moreover, in the prior art 2, the axis | shaft which passes along two planetary gear mechanisms has a triple structure in many places.

  Since the vehicle drive device affects the behavior control of the vehicle, responsiveness is important. However, if the structures of the first coupling member and the second coupling member are different, the first coupling member and the second coupling are connected from two driving sources. When equal power is input to the member, there is a difference in the responsiveness of the left and right wheels, and the driver may feel uncomfortable when driving the vehicle, particularly when starting or accelerating.

  Therefore, the present invention combines two planetary gear mechanisms with three elements and two degrees of freedom on the same axis between two drive sources mounted on a vehicle and independently controllable, and left and right drive wheels. In a vehicle drive device having a gear device that amplifies the torque difference from one drive source to the left and right drive wheels, the torque response of the left and right wheels is made equal to improve the stability of the vehicle behavior, and when the driver is driving the vehicle In particular, it is an object to avoid feeling uncomfortable when starting or accelerating.

  In order to solve the above-described problems, the present invention provides a three-element and two-degree-of-freedom planetary gear mechanism coaxially between two drive sources mounted on a vehicle and independently controllable and left and right drive wheels. Two combinations, a specific element of one planetary gear mechanism and a specific element of the other planetary gear mechanism are connected to each other by a first coupling member and a second coupling member to drive left and right from two driving sources. In the vehicle drive device provided with a gear device that amplifies a torque difference between the wheels, the shape and dimensions of the first coupling member and the second coupling member are equal to the first coupling member and the second coupling member from the two driving sources. When torque is input, the torsion angles of the first coupling member and the second coupling member are set to be equal.

  Each of the planetary gear mechanisms includes an internal gear, an output 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 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. Can be configured.

  The first coupling member and the second coupling member are arranged coaxially, one coupling member has a hollow shaft, and the other coupling member has a shaft inserted through the hollow shaft. The axis passing between them can be a double structure.

  A speed reducer that transmits power of the two drive sources to the drive wheel, the speed reducer coupled to the drive source; an input gear shaft having an input gear; and an output having an output gear coupled to the drive wheel. At least one intermediate gear shaft that transmits power between the input gear shaft and the output gear shaft by meshing with the gear shaft is arranged, and the outer peripheral portion of the internal gear meshes with the input gear of the input gear shaft. Gears can be provided.

  A housing of the vehicle drive device has a three-piece configuration including a central housing and left and right side housings, and 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 second coupling A member can be provided through the partition wall.

  The first coupling member and the second coupling member are arranged coaxially, one coupling member is a hollow shaft, and the other coupling member is a double structure including a shaft inserted into the hollow shaft, Spline fitting can be used to connect the first coupling member and the second coupling member to the planet carrier to which the respective coupling members are coupled.

  On the outboard side of the planetary carrier, an output-side small-diameter gear that meshes with the output gear or the gear of the driven intermediate gear shaft may be provided.

  An output-side small-diameter gear that meshes with the output gear or the gear of the intermediate gear shaft on the driven side may be provided on the inboard side of the planetary carrier.

  In the present invention, since the problem is solved by equalizing the torsion angles of the shaft portions of the first coupling member and the second coupling member, the backlash between the sun gear and the planetary gear in the two planetary gear mechanisms, etc. In addition, the play of the spline fitting portion between the first and second coupling members and the planet carrier is assumed to be the same on the left and right.

  In the present invention, the axial lengths of the two coupling members are substantially determined by the arrangement of the planetary gear mechanism.

  Further, for example, when one of the coupling members has a double structure including a hollow shaft and the other coupling member is inserted into the hollow shaft, the inner coupling member has an outer diameter larger than that of the outer coupling member. Is small and the axial dimension is large, and the torsional rigidity is small. That is, the torsion angle increases. If the outer diameter of the inner coupling member is increased in order to make the torsion angles of the two coupling members equal, the mass increases. Conversely, if the outer diameter of the outer coupling member is reduced, the mass can be reduced. Therefore, in order to make the torsion angles of the two coupling members equal, the outer diameter of the outer coupling member is reduced when determining the geometric dimensions. That is, it is made equal to the smaller torsional rigidity.

  In addition, when determining the dimensions of each coupling member, ensuring the necessary strength is a major premise.

  The shape and dimensions of each coupling member are determined so that the torsion angles are equal. However, since there are uncertain factors such as processing accuracy and assembly accuracy, it is very difficult to completely match the torsion angles of each coupling member. Further, since the allowable range of the difference in torsion angle of each coupling member differs depending on the vehicle concept, for example, depending on the vehicle concept, the torsion angle of the outer coupling member with respect to the torsion angle of the inner coupling member. In the present invention, it can be said that the torsion angles are equal.

  As described above, in the present invention, when the same power is input from the two drive sources to the first coupling member and the second coupling member, the torsion angles of the first coupling member and the second coupling member become equal. The shape dimensions.

The shape dimensions referred to here are the lengths of the inner and outer diameters of each coupling member, the spline fitting center between each coupling member and the planet carrier, and the meshing center between the sun gear and the planetary gear (L ₁ in FIG. See L ₂ ).

  For example, when considering a simple torsion in which bending does not act on shaft components having different diameters in the axial direction, the torsion angle θ is expressed by Equation 1.

Here, M _t is a torsional moment acting on the shaft, and G is a shear elastic modulus (transverse elastic modulus), which is a constant determined by the material. Further, L _i (i = 1, 2,..., N) is the length of the shaft having each diameter d _i (i = 1, 2,..., N), and the length of the entire shaft is L. , L = L ₁ + L ₂ +... + L _n . Furthermore _{J i (i = 1,2, ...} , n) is a constant torsion on each diameter, represented by the polar moment of inertia I _P axis (J _i = _{I Pi).}

In the present invention, when the shaft for calculating the torsion angle is a hollow shaft as described above, the cross-sectional secondary pole moment I _P is expressed by Equation 2 where d _{1 is} the inner diameter of the hollow shaft and d ₂ is the outer diameter. The

  As described above, when the same torsional moment is applied to hollow shaft members having different inner and outer diameters and lengths using two identical materials, in order to equalize both torsion angles, the respective members represented by Formula 1 are used. The inner and outer diameters and lengths of the members may be set so that the torsion angles are equal.

  However, in the case of considering the torsion of a shaft having a complicated shape such as a gear engaging part or a spline fitting part like the first connecting member and the second connecting member in the present invention, the simulation by the CAE analysis or the torsion It is also possible to determine the shape dimension by calculating the torsion angle by measurement by a test.

  As described above, according to the present invention, when the same torque is input to the first coupling member and the second coupling member from the two driving sources, Since the first connecting member and the second connecting member are set to have the same torsion angle, the torsional rigidity of the first connecting member and the second connecting member is the same, and there is no difference in response between the left and right wheels. However, when the vehicle is driven, particularly when starting or accelerating, it is possible to avoid feeling uncomfortable.

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 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 other 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 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.

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

  The electric vehicle AM shown in FIG. 3 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. In FIG. 3, the gear structure of the vehicle drive device 1 is shown with the skeleton figure.

  1 and 3 includes two electric motors 2L and 2R that are mounted on a vehicle and can be controlled independently, left and right driving wheels 61L and 61R, and two electric motors 2L, 2R left and right reduction gears 3L, 3R provided between 2R.

  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 system or a four-wheel drive system may be used in addition to the rear wheel drive system shown in FIG.

  The left and right electric motors 2L and 2R in the two-motor type vehicle drive device 1 use the same standard electric motors having the same maximum output, and are housed in the motor housings 4L and 4R as shown in FIG. Yes.

  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 housing 9 that accommodates the two reduction gears 3L and 3R provided in parallel in the left and right is divided into three pieces in a direction perpendicular to the gear shaft of the reduction gears 3L and 3R. As shown in FIG. The left and right side housings 9bL and 9bR are 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).

  By fixing the side surfaces 9bL and 9bR of the 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 with a plurality of bolts 10, Two electric motors 2L and 2R are fixedly arranged on the left and right sides of the housing 9 (FIG. 1).

  As shown in FIG. 1, the central housing 9a is provided with a partition wall 11 at the center. The 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 reduction gears 3 </ b> L and 3 </ b> R are provided in parallel.

  As shown in FIG. 1, the reduction gears 3L and 3R are provided in a bilaterally symmetric shape. Power is transmitted from the motor shaft 5a, and the input gear shafts 12L and 12R having the input gear 12a are meshed with the input gear 12a. The intermediate gear shafts 13L, 13R having the output side small gear 13b meshing with the input side external gear 13a and the output gear 14a, and the output gear 14a are drawn out from the housing 9 and are constant velocity joints 65a, 65b, the intermediate shaft. This is a parallel shaft gear reducer including output gear shafts 14L and 14R that transmit torque to the drive wheels 61L and 61R via 65c (FIG. 3). 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 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 meshing with the input gear 12a and an output side small diameter gear 13b meshing 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 device 30 includes a planetary gear mechanism having three elements and two degrees of freedom, which are coaxially combined with a pair of left and right intermediate gear shafts 13L and 13R arranged coaxially.

As shown in the enlarged view of FIG. 2, 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 planet carrier C _L provided coaxially, C _R and the left one of the planet carrier C _L (in FIG. 2 FIG. ) And the other sun gear S _R (the right side of the figure in FIG. 2), one sun gear S _L (the left side of the figure in FIG. 2) and the other planet carrier C _R (the figure). a second coupling member 32 for coupling the two in the right hand side of the drawing), the internal gear R _L, linked to R _R, the input gear shaft 12L, 12R The intermediate gear 13a includes an input side external gear 13a of the intermediate gear shafts 13L and 13R meshing with the input gear 12a, and an output side small gear 13b of the intermediate gear shafts 13L and 13R meshing with the output gear 14a of the output gear shafts 14L and 14R. The output side small-diameter gear 13b of the 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 input gear 12a of the plurality of pairs of intermediate gear shafts 13L and 13R. The output side small gear 13b is arranged to mesh with the gears provided on the driven intermediate gear shafts 13L and 13R of the plural pairs of intermediate gear shafts 13L and 13R. Be placed.

In the embodiment shown in FIG. 2, 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. 2, 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.

  In the embodiment shown in FIG. 2, the output side small gear 13b and the output gear 14a of the output gear shafts 14L and 14R are provided on the outboard side (outside of the vehicle) of the vehicle drive device 1. As in the embodiment shown in FIG. 6, the vehicle drive device 1 may be provided on the inboard side (inside the vehicle).

As shown in FIG. 2, the planetary carriers C _L and C _R are composed of a carrier pin 33 that supports the planetary gears P _L and P _R , and an outboard side carrier flange that is connected to the outboard side end of the carrier pin 33. 34a and an inboard carrier flange 34b connected 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 housing 9. It is supported in the hole 19b 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.

  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 constituting the gear device 30 of the vehicle drive device 1 penetrate the partition wall 11 that partitions the central housing 9a of the housing 9 to the left and right. Built in.

  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. (The first coupling member 31 in the embodiment of FIGS. 1 and 2) has a double structure consisting of a shaft inserted through a hollow shaft, and the shaft diameters of the first coupling member 31 and the second coupling member 32 are different. Usually, the torsional rigidity of the first coupling member 31 and the second coupling member 32 is different, but in the present invention, the torsional angles of the first coupling member 31 and the second coupling member 32 are made equal to increase the responsiveness of the left and right wheels. There is no difference.

  In other words, when the second coupling member 32 has a double structure including a hollow shaft and the first coupling member 31 includes a shaft inserted into the hollow shaft, the inner coupling member has an outer diameter that is larger than that of the outer coupling member. Since the torsional rigidity is small because the axial dimension is small and the axial dimension is large, for example, when determining the geometric dimension in order to make the torsion angles of the first coupling member 31 and the second coupling member 32 equal, The outer diameter of the coupling member 32 is reduced so as to be equal to the smaller torsional rigidity.

1 and in the embodiment shown in FIG. 2, the second coupling member 32 and the end portion of the right side of the planetary gear mechanism, the planet carrier C carrier on the inboard side of the _R flange 34b of the hollow shaft portion 36 composed of a hollow shaft DOO splines 41 provided on the second coupling member 32 to the planet carrier C _R are coupled by spline-fitting.

Moreover, the spline 42 in the embodiment shown in FIGS. 1 and 2, the end portion of the left planetary gear mechanism of the first coupling member 31, and the hollow shaft portion 35 of the carrier flange 34a on the outboard side of the planet carrier C _L the provided, it is connected by spline fitting to the first coupling member 31 the planet carrier C _L.

As described above, the two first coupling member 31 of the planetary gear mechanism and a second coupling member 32, by connecting the splined to the planet carrier C _L and the planet carrier C _R, two planetary gear mechanism Can be divided into left and right, and can be assembled into the three-piece 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 the end on the right planetary gear mechanism side, and on the outer peripheral surface of the large diameter portion 43, external gear is formed to mesh with the planetary gears P _R of the right planetary gear mechanism, the external gear constitutes the sun gear S _R of the right planetary gear mechanism.

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 41 and 42) 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 41 and 42) fitting portion is 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 is the coupling member (the first coupling member 31 in the embodiment of FIGS. 1 and 2). 1 coupling member 31) and the planetary carrier (C _{L in the} embodiment of FIGS. 1 and 2), the shaft end opposite to the spline fitting, and the other planet carrier (C _{R in the} embodiment of FIGS. 1 and 2) ) Is supported by a deep groove ball bearing 49.

  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 is provided with an oil supply hole 50 in the shaft center. 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 housing 9 through openings formed in the side housings 9bL and 9bR, and the outboard side ends of the output gear shafts 14L and 14R are drawn out. The outer joint portion of the constant velocity joint 65a is spline-coupled to the outer peripheral surface.

  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. 3).

  An oil seal 55 is provided between the end of the output gear shafts 14L and 14R on the outboard side and the openings formed in the side housings 9bL and 9bR. Intrusion of muddy water is prevented.

  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. 3, 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 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 a planet carrier C is provided coaxially with the sun gears S _L and S _R and the internal gears R _L and R _{R. 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 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 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 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 and the sun gear S _{R of} the second planetary gear mechanism are coupled to form the first coupling member 31, and the sun gear S _{L of} the first planetary gear mechanism is formed. When the planet carrier C _R of the second planetary gear mechanism forms a second coupling member 32 are coupled.

The torque TM1 generated by the electric motor 2L in the internal gear _RL of the first planetary gear mechanism is transmitted to the intermediate gear shaft 13L through the meshing of the input gear 12a of the input gear shaft 12L and the input side external gear 13a, and the intermediate gear shaft 13L. The torque transmitted to the shaft 13L is transmitted to the output-side small gear 13b of the intermediate gear shaft 13L via the first planetary gear mechanism, and the output gear of the output-side small gear 13b of the intermediate gear shaft 13L and the output gear shaft 14L. 14a meshes with the output gear shaft 14L and the drive torque TL is output to the drive wheel 61L.

Torque TM2 generated by the electric motor 2R to the internal gear R _R of the second planetary gear mechanism includes an input gear 12a of the input gear shaft 12R and the input-side external gear 13a is transmitted to the intermediate gear shaft 13R meshing, intermediate gear The torque transmitted to the shaft 13R is transmitted to the output-side small gear 13b of the intermediate gear shaft 13R via the second planetary gear mechanism, and the output gear of the output-side small gear 13b of the intermediate gear shaft 13R and the output gear shaft 14R. The drive torque TR is output from the output gear shaft 14R to the drive wheel 61R.

Electric motor 2L, the output from the 2R, each internal gear R _L of the two planetary gear mechanisms, given R _R, the first coupling member 31, the output from the second coupling member 32 is the driving wheel 61L, the 61R Given.
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 velocity diagrams are shifted up and down, the velocity diagram of the left planetary gear mechanism is shown on the upper side, and the velocity diagram of the right planetary gear mechanism 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. 4 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.

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 based on the point of R _R. In FIG. 4, the arrow direction M in the figure is the positive direction of the moment.
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.

  Then, when different torques TM1 and TM2 are generated by the two electric motors 2L and 2R to give the input torque difference ΔTIN (= (TM2−TM1)), the input torque difference ΔTIN is amplified in the gear device 30, 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 shape and dimensions of the first coupling member and the second coupling member that couple the two planetary gear mechanisms constituting the gear device 30 that is the torque difference distribution mechanism are changed from the two driving sources to the first coupling member and the first coupling member. By setting the torsion angles of the first and second coupling members to be equal when the same torque is input to the two coupling members, the vehicle behavior can be improved by equalizing the torque responsiveness of the left and right wheels. It is possible to improve the stability of the vehicle so that the driver does not feel uncomfortable when driving the vehicle, particularly when starting or accelerating.

Furthermore, in the present invention, connection of the two planetary gear mechanism constituting the gear device 30 is a torque difference distribution mechanism, the sun gear S _L and the planet carrier C _R, since it is the sun gear S _R and the planet carrier C _L, A connecting member having a larger diameter than the internal gears R _L and R _R is not 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.

  Further, there is a merit that the vehicle interior space is expanded by downsizing the vehicle drive device 1.

  As described above, in the embodiment shown in FIGS. 1 and 2, the output gear 14a of the output gear shafts 14L and 14R is provided closer to the outboard (outside of the vehicle) of the reduction gears 3L and 3R. In the embodiment shown in FIG. 2, an output gear 14a and output gear shafts 14L and 14R are provided near the inboard (inner side of the vehicle) of the reduction gears 3L and 3R.

  The embodiment shown in FIGS. 5 and 6 is different from the embodiment shown in FIGS. 1 and 2 in that the output gear 14a of the output gear shafts 14L and 14R is closer to the outboard (outside of the vehicle) of the reduction gears 3L and 3R. The embodiment shown in FIG. 5 and FIG. 6 differs from the embodiment shown in FIG. 1 and FIG. 2 because there is only a difference between whether it is provided or closer to the inboard (inside the vehicle) of the speed reducers 3L and 3R. By attaching the same reference numerals, redundant description is omitted.

  In the embodiment shown in FIG. 1, the electric motors 2 </ b> L and 2 </ b> R are used as the two drive sources, and the same standard electric motor having the same maximum output is illustrated, 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 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 7: Sealing members 8a and 8b: Rolling bearing 9: Housing 9a: Central housing 9bL and 9bR: Side housing 10: Bolt 11: Partition walls 12L and 12R: Input gear shaft 12a: Input gear shaft 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 holes 20a 20b: Rolling bearing 30: Gear device 31: First coupling member 32: Second Joint 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: Bearings 47, 48: Thrust bearing 49: Deep groove ball bearing 50: Oil supply holes 51, 52: Oil supply passages 53a, 53b: Bearing fitting holes 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 M: Moment P _L , P _R : Planetary gears R _L , R _R: the internal gear S _L, S _R: sun gear TM1, TM2: torque generated by the electric motor TL, TR: Dynamic torque Zr: number of teeth Zs of the internal gear: the number of teeth a of the sun gear, b: Distance alpha: torque difference gain DerutaTIN: input torque difference DerutaTOUT: drive torque difference

Claims (8)

  Two planetary gear mechanisms with three elements and two degrees of freedom are coaxially combined between two drive sources mounted on the vehicle and independently controllable and the left and right drive wheels, and specific elements of one planetary gear mechanism And a specific element of the other planetary gear mechanism connected to each other by a first coupling member and a second coupling member, and a vehicle provided with a gear device that amplifies a torque difference from two drive sources to the left and right drive wheels In the driving device, the first coupling member and the second coupling member having the same dimensions as the first coupling member when torque equal to the first coupling member and the second coupling member is input from the two driving sources. And the second coupling member are set to have the same torsion angle.   Each of the planetary gear mechanisms includes an internal gear, an output 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 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 apparatus according to claim 1.   The first coupling member and the second coupling member are arranged coaxially, one coupling member has a hollow shaft, and the other coupling member has a shaft inserted through the hollow shaft. The vehicle drive device according to claim 1, wherein an axis passing therethrough has a double structure.   A speed reducer that transmits power of the two drive sources to the drive wheel, the speed reducer coupled to the drive source; an input gear shaft having an input gear; and an output having an output gear coupled to the drive wheel. At least one intermediate gear shaft that transmits power between the input gear shaft and the output gear shaft by meshing with the gear shaft is arranged, and the outer peripheral portion of the internal gear meshes with the input gear of the input gear shaft. The vehicle drive device according to claim 1, further comprising a gear.   A housing of the vehicle drive device has a three-piece configuration including a central housing and left and right side housings, and 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 second coupling The vehicle drive device according to claim 1, wherein a member penetrates the partition wall.   The first coupling member and the second coupling member are arranged coaxially, one coupling member is a hollow shaft, and the other coupling member is a double structure including a shaft inserted into the hollow shaft, The vehicle drive device according to any one of claims 1 to 5, wherein the connection between the first coupling member and the second coupling member and the planet carrier to which the respective coupling members are coupled is spline fitting.   5. The vehicle drive device according to claim 4, wherein an output-side small-diameter gear that meshes with an output gear or a gear of an intermediate gear shaft on the driven side is provided on the outboard side of the planetary carrier.   5. The vehicle drive device according to claim 4, wherein an output-side small-diameter gear that meshes with an output gear or a gear of a driven intermediate gear shaft is provided on the inboard side of the planetary carrier.

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