JP2003127681A - Hybrid vehicle drive structure with transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a second motor generator MG2 from being large and to obtain required axle torque characteristics against speed while properly maintaining the fuel consumption of an internal combustion engine, in hybrid vehicle drive structure in which an output shaft of the internal combustion engine is connected to a first motor generator and a wheel drive shaft through a power distribution mechanism, and a second motor generator is connected to the wheel drive shaft. SOLUTION: Transmissions (100, 101, 102) are provided at least either at the middle of a wheel drive shaft or at the middle of the connection of the second motor generator to the wheel drive shaft.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid vehicle drive structure in which wheels are driven by a combination of an internal combustion engine and an electric motor.

[0002]

2. Description of the Related Art In recent years, hybrid vehicles in which wheels are driven by a combination of an internal combustion engine and an electric motor have been in the limelight in recognition of the increasing importance of environmental protection and fuel resource saving. . When driving the wheels of an automobile, which require various combinations of rotational speed and driving torque, by an internal combustion engine and an electric motor, various driving modes may be possible. Originally, it was driven exclusively by an internal combustion engine, and hybrid vehicles in the field of automobiles started by replacing some conventional internal combustion engine-only drive with electric drive as far as the situation allows. Therefore, it is considered natural that even a hybrid vehicle can be driven only by the internal combustion engine. JP-A-11-
In 198669, a first motor / generator is connected in series to a crankshaft of an internal combustion engine to form a power shaft driven by either or both of the internal combustion engine and the electric motor. A hybrid vehicle drive structure is shown in which an output shaft of a generator is connected to and combined with a ring gear and a sun gear of a planetary gear mechanism, and a carrier of the planetary gear mechanism is used as an output shaft and a transmission is connected to the carrier. . According to such a hybrid vehicle drive structure, even if only the internal combustion engine is used as a prime mover, the shift function of the transmission is obtained, and it is possible to cope with various operating modes required for a vehicle, like a conventional internal combustion engine vehicle. This seems to be one of the typical examples reflecting the origin of the hybrid vehicle as described above.

On the other hand, however, on the occasion of combining an internal combustion engine and an electric motor as a prime mover of an automobile, the internal combustion engine is caused by the difference between the rotational speed required for the wheels and the driving torque and the rotational speed obtained from the internal combustion engine versus the driving torque. By the same person as the applicant of the present application, it is possible to differentially absorb the difference in rotation speed between the output shaft and the axle by the electric motor and eliminate the transmission that has been conventionally required between the internal combustion engine output shaft and the axle. was suggested. FIG. 1 attached herewith is a schematic view showing a drive structure of such a hybrid vehicle.

In FIG. 1, reference numeral 1 denotes an internal combustion engine, which is mounted on a vehicle body (not shown). Reference numeral 2 is its output shaft (crank shaft). 3 is a planetary gear device, 4 is its sun gear, 5 is a ring gear, 6 is a planetary pinion, and 7 is a carrier. The crankshaft 2 is connected to the carrier 7. 8 is the first motor generator (MG
1), which has the coil 9 and the rotor 10, and the rotor 10
Is connected to the sun gear 4. The coil 9 is supported by the vehicle body. One end of a propeller shaft 11 is connected to the ring gear 5. Thus, the planetary gear device 3 constitutes a power distribution mechanism that distributes the output of the internal combustion engine, which appears on the output shaft 2 of the internal combustion engine, to the first motor generator 3 and the propeller shaft 11 that serves as a wheel drive shaft. A second motor generator (MG2) 12 is connected in the middle of the propeller shaft 11.
The second motor generator 12 has a coil 13 and a rotor 14, and the coil 13 is supported by the vehicle body. The connection of the rotor 14 to the propeller shaft 11 may have any structure, but in the illustrated example, the structure is such that the gear 15 provided on the propeller shaft 11 meshes with the rotating gear 16 supported by the rotor 14. ing. The other end of the propeller shaft 11 is connected to a pair of axles 18 via a differential device 17. Wheels 19 are attached to each of the axles 18.

In the illustrated drive structure, the rotation of the crankshaft 2 and the rotation of the carrier 7 are the same, and this rotation speed is now represented by Nc. Further, the rotation of the first motor generator 8 and the rotation of the sun gear 4 are the same, and this rotation speed is now represented by Ns. On the other hand, the rotation of the ring gear 5, the rotation of the second motor generator 12, and the rotation of the wheels 19 correspond to each other and finally correspond to the vehicle speed, but the respective rotation speeds are those of the gears 15 and 16. It depends on the ratio of the number of teeth between them, the speed reduction ratio in the differential device 17, and the tire diameter. However, here, for the sake of convenience, the rotational speed of these portions is represented by the rotational speed of the ring gear 5, and is represented by Nr. Then, between the internal combustion engine and the two motor generators MG1, MG2 in the hybrid vehicle drive structure in which the internal combustion engine and the two motor generators are combined by a planetary gear device as shown in the drawing, between the rotational speeds Nc, Ns, Nr. The relationship is expressed by the diagram shown in FIG. 2 based on the principle of the planetary gear device. In the figure, ρ is the number of teeth of the sun gear with respect to the number of teeth of the ring gear (ρ <1). Since Nc is determined by the engine speed and Nr is determined by the vehicle speed, Ns is determined as Ns = (1 + 1 / ρ) Nc− (1 / ρ) Nr depending on the engine speed and the vehicle speed.

On the other hand, if the torques of the carrier, sun gear, and ring gear are Tc, Ts, and Tr, these are Ts: Tc: Tr = ρ / (1 + ρ): 1: 1 / (1+
When a ratio of ρ) balances each other, and thus any of these three elements produces or absorbs torque, torque is exchanged between them until the above balance is established.

In the hybrid vehicle having the above-described drive structure, the internal combustion engines, MG1 and MG2 are operated by a vehicle operation control device (not shown) from the driver and operation of the vehicle. It is controlled based on the state and.
That is, the vehicle operation control device includes a microcomputer, calculates the target vehicle speed and the target wheel drive torque based on the operation command of the driver and the operation state of the vehicle detected by various sensors, and charges the power storage device. Based on the state, calculate the current output allowed for the power storage device or the amount of power generation required for charging the power storage device, and based on these calculation results, what operating state should the internal combustion engine operate in, including stoppage, In addition, calculate what kind of electric or electric power generation state MG1 and MG2 should be operated in,
The operation of the internal combustion engine, MG1 and MG2 is controlled based on the calculation result.

[0008]

As described above, the output shaft of the internal combustion engine is connected to the first motor / generator and the wheel drive shaft through the power distribution mechanism, and the wheel drive shaft is provided with the second motor / generator. According to the connected hybrid vehicle drive structure, as can be understood from FIG. 2, the respective values of the rotation speed Nc of the internal combustion engine output shaft and the rotation speed Nr corresponding to the vehicle speed and the relative relationship between them show the change. Since it can be drastically changed by absorbing the rotation speed Ns of one motor-generator, the transmission has not been required in the hybrid vehicle drive structure. That is, depending on the adjustment of the power distribution mechanism,
It is possible to freely change the relationship between Nc and Nr, and to operate the engine (Nc> 0) even when the vehicle is stopped (Nr = 0), and conversely, when the vehicle is moving forward (Nr> 0). Also, the engine can be stopped (Nc = 0), or it can be moved backward (Nr <0) regardless of whether the engine is running or stopped (Nc ≧ 0).

However, the number of revolutions of MG2 depends on the vehicle speed, and the degree of charge of the power storage device is irrelevant to the vehicle speed. Therefore, MG2 has a large limitation in operating as a generator for charging the power storage device. There is. Therefore, charging of the power storage device depends exclusively on MG1, and conversely, electric drive of the wheels depends exclusively on MG2. Therefore, in the hybrid vehicle drive structure as described above, which is not provided with a transmission, in order to secure the vehicle driving performance capable of obtaining a high wheel drive torque as necessary even in the low vehicle speed range, the quality MG2 Is inevitably larger.

This is shown in FIG. 3 as a performance characteristic diagram of axle torque with respect to vehicle speed. That is, now, the internal combustion engine of the vehicle should be operated with high fuel efficiency over a wide range of vehicle speeds, and the vehicle should have the performance shown by line A as the limit performance desired as the vehicle speed vs. axle torque performance. Then, since the vehicle speed versus axle torque performance of the internal combustion engine that obtains high fuel consumption becomes almost flat as in region B, the rest must be compensated exclusively with MG2, and the vehicle velocity versus axle torque performance covers region C. Must be something. Therefore, the MG2 must be large enough to generate high torque at a low rotation speed.

However, when examining FIG. 3, it is doubted that the depth of the region C is a little too deep as compared with the depth of the region B. From a different point of view, this is a problem of the relative balance between the sizes of the internal combustion engine and the three prime movers, that is, the first and second motor-generators, and particularly the size balance between the internal combustion engine and the second motor-generator. Is. The present invention originates from such a question, and an object of this point is to further improve the hybrid vehicle drive structure as described above.

[0012]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides an output shaft of an internal combustion engine, which is connected to a first motor / generator and a wheel drive shaft through a power distribution mechanism to drive the wheel. In a hybrid vehicle drive structure in which a second motor / generator is connected to a shaft, a transmission is provided at least in the middle of the wheel drive shaft or in the middle of connection of the second motor / generator to the wheel drive shaft. The present invention proposes a hybrid vehicle drive structure characterized by the provision of.

The term "motor generator" refers to means having both functions of an electric motor and a generator. In the present invention, however, the output shaft of the internal combustion engine passes through the power distribution mechanism to drive the first motor generator and the wheels. The present invention relates to a short-term vehicle drive performance of a hybrid vehicle drive structure in which a second motor / generator is connected to a shaft and the wheel drive shaft is connected, in other words, to an internal combustion engine drive in a hybrid drive of the vehicle. , Electric drive,
As far as the operation and effect of the present invention are concerned, both the first and second motor-generators are mere electric motors because they are not related to the long-term vehicle driving performance in which the mutual relationship of the self-charging action on the power storage device is involved. It's good. Certainly, as a vehicle drive device that actually works, as already mentioned, the second motor generator has to operate exclusively as an electric motor (but it can also operate as a generator),
Therefore, in order to construct a vehicle drive device that can operate for a long period of time, the first motor generator must have a power generation function, but this need is not related to the technical idea of the present invention. That is. Therefore, in the configuration of the present invention, the means described as a motor generator includes a motor having no power generation function as its equivalent.

In the hybrid vehicle drive structure as described above, the transmission may be provided on the side of the internal combustion engine with respect to the connecting portion of the second motor generator in the middle of the wheel drive shaft.

Alternatively, in the hybrid vehicle drive structure as described above, the transmission is provided in the middle of the wheel drive shaft on the side separated from the internal combustion engine with respect to the connecting portion of the second motor generator. You may

Further, in the hybrid vehicle drive structure as described above, the transmission may include a reverse gear. In this case, the hybrid vehicle drive structure may further include means for selecting between vehicle reverse drive by the reverse stage of the transmission and vehicle reverse drive by adjusting the power distribution mechanism.

[0017]

As described above, the output shaft of the internal combustion engine is connected to the first motor generator and the wheel drive shaft via the power distribution mechanism, and the wheel drive shaft is connected to the second motor generator. In the hybrid vehicle drive structure, if the transmission is provided at least in the middle of the wheel drive shaft or the connection of the second motor / generator to the wheel drive shaft, the high axle at a low vehicle speed. When the torque is obtained, if the transmission is provided on the side of the internal combustion engine with respect to the connecting portion of the second motor generator in the middle of the wheel drive shaft, the power distribution mechanism is adjusted. By increasing the number of revolutions of the internal combustion engine relative to the vehicle speed and increasing the reduction ratio of the transmission, the internal combustion engine can cover more of the required high axle torque, and the torque required for the second motor generator can be obtained. To meet this demand without diminishing If the transmission is provided in the middle of the wheel drive shaft and on the side separated from the internal combustion engine with respect to the connecting portion of the second motor generator, the internal combustion engine is adjusted by adjusting the power distribution mechanism. Increase engine speed relative to vehicle speed,
By increasing the reduction ratio of the transmission, the wheels are driven by the cooperation of the internal combustion engine and the second motor / generator at the increased reduction ratio to reduce the torque required for the second motor / generator. If the transmission is provided in the middle of the connection of the second motor / generator to the wheel drive shaft, the transmission can be adjusted regardless of the adjustment of the power distribution mechanism. The wheel drive torque obtained from the second motor / generator can be increased by increasing the reduction ratio of the transmission, and even if the second motor / generator is made to have a moderate size, it is possible to meet this requirement. Thus, while maintaining a favorable balance between the relative sizes of the internal combustion engine and the first and second motor-generators, the internal combustion engine is always operated at high fuel efficiency, as shown by the line A in FIG. Such vehicle speed versus axle torque performance can be obtained.

Further, in the hybrid vehicle drive structure as described above, if the transmission is configured to include the reverse gear, the gear can be moved to the reverse gear without adjusting the power distribution mechanism during the reverse movement of the vehicle. By switching to, it is possible to easily reverse the vehicle. In this case, if means is provided for selecting between reverse drive of the vehicle by the reverse gear of the transmission and reverse drive of the vehicle by adjusting the power distribution mechanism, in particular, if the vehicle is climbing backward on a slope or the drive wheels are depressed. When it is necessary to drive the vehicle backwards with a high axle torque, such as when the vehicle is sunk, it is possible to handle it with sufficient driving torque by selecting the vehicle reverse driving with the reverse gear of the transmission, and it is possible to reverse the vehicle on a normal level. When the axle torque to the left is not required, by selecting the vehicle reverse drive by adjusting the power distribution mechanism, it is possible to achieve quick reverse without transmission change operation.

Furthermore, the above-described transmission may itself be the one in which the known overdrive stage is already the maximum speed in various modes, so that even in a hybrid vehicle, high speed operation of the vehicle is possible. The operation of the internal combustion engine can be optimized as in a conventional internal combustion engine with overdrive.

[0020]

4, 5, and 6, the output shaft of an internal combustion engine is connected to a first motor / generator and a wheel drive shaft through a power distribution mechanism, as shown in FIG. In the hybrid vehicle drive structure in which the second motor generator is connected to the drive shaft,
FIG. 1 shows three embodiments incorporating a transmission according to the invention.
It is a schematic diagram similar to. 4, 5, and 6, parts corresponding to the parts shown in FIG. 1 are indicated by corresponding reference numerals.

In the first embodiment shown in FIG. 4, the transmission 100 is provided in the middle of the wheel drive shaft and closer to the internal combustion engine than the connecting portion of the second motor generator MG2. In terms of the description of FIG. 1, it is a part of the propeller shaft 11 that forms a part of the wheel drive shaft, and is provided closer to the internal combustion engine than the gear 15 that forms a connecting portion of the MG 2. The transmission 100 may have two or three gears, and may further include a reverse gear. Although such a transmission can be obtained in various modes by a known technique, an example of a transmission having three forward gears and a reverse gear is schematically shown in FIG.

In FIG. 7, reference numerals 20, 22, 24 and 26 designate a sun gear, a ring gear and a planetary gear mechanism, respectively.
Planetary pinion, carrier, also 21, 2
3, 25 and 27 are sun gears, ring gears, planetary pinions and carriers that constitute another planetary gear mechanism, and 28 (C1) and 29 (C2) are clutches,
30 (B1) and 31 (B2) are brakes, 32
(F1) is a one-way clutch. These rotary elements have 33 as an input shaft and 34 as an output shaft,
In the meantime, if it is combined as shown, the clutch C
The first speed stage having the largest reduction ratio is achieved by engaging 1 and the second speed stage having an intermediate reduction ratio is achieved by engaging the clutch C1 and the brake B1. And C2 are engaged, the third speed ratio having the smallest reduction ratio (reduction ratio = 1) is achieved, and the clutch C
The reverse gear is achieved by the engagement of 2 and the brake B2.

In the embodiment of FIG. 4, the transmission 100 has three
Assuming that gear shifting is applied, the performance characteristic diagram of vehicle speed versus axle torque is changed as shown in FIG. 8 in comparison with FIG. 3 in the case where such a transmission is not provided. In this diagram, areas B1, B2, and B3 respectively represent the first transmission.
The region C that is mainly covered by the internal combustion engine (in some cases, the internal combustion engine and MG1) by setting the speed, the second speed, and the third speed, and the remaining region C is the second motor generator M
This is an area covered by G2. It will be understood from FIG. 8 that the maximum torque required for MG2 is significantly reduced as compared with the case of FIG.

In the second embodiment shown in FIG. 5, the transmission 101 is provided in the middle of the wheel drive shaft and on the side separated from the internal combustion engine with respect to the connecting portion of the second motor generator MG2. In terms of the description of FIG. 1, a part of the propeller shaft 11 forming a part of the wheel drive shaft is provided on the side farther from the internal combustion engine than the gear 15 forming the connecting part of the MG2. Has been. The transmission 101 may also have two or three gears, may further include a reverse gear, and may be as shown in FIG.

In the embodiment of FIG. 5, the transmission 101 has three
Assuming that the gear shift is applied, the performance characteristic diagram of vehicle speed versus axle torque is changed as shown in FIG. 9 as compared with FIG. 3 in the case where such a transmission is not provided. In this diagram, the regions B1 + C1, B2 + C2, B3 + C3 mainly represent the internal combustion engine (in some cases, the internal combustion engine and MG1) by setting the transmission to the first speed, the second speed, and the third speed, respectively. This is an area covered by MG2.
Also in this case, as can be seen from FIG. 9, the maximum torque required for MG2 is significantly reduced as compared with the case of FIG.

In the third embodiment shown in FIG. 6, the transmission 102 is provided in the middle of the connection of the second motor generator MG2 to the wheel drive shaft, and the description of FIG. In other words, it is provided at the connecting portion of the MG 2 to the propeller shaft 11 that forms a part of the wheel drive shaft. The transmission 102 may also have two or three gears. In this case, MG2
Since the reverse rotation drive can be easily performed by switching the electric circuit, the transmission 102 does not need to have the reverse gear. But,
The transmission 102 may also include a reverse gear and may be as shown in FIG.

In the embodiment of FIG. 6, the transmission 102 has three
Assuming that gear shifting is applied, the performance characteristic diagram of vehicle speed versus axle torque is changed as shown in FIG. 10 as compared with FIG. 3 in the case where such a transmission is not provided. In this diagram, the region B is a region mainly covered by the internal combustion engine (in some cases, the internal combustion engine and MG1), and the regions C1, C2, and C3 respectively set the transmission to the first speed and the second speed.
This is an area covered by MG2 by setting the speed and the third speed. In FIG. 10, a region C1 shows a torque region in which the torque corresponding to the region B is obtained by the internal combustion engine and then the output torque of the MG2 is added by the torque increased by the first gear transmission. Area C2, C3
Also shows the same thing. As can be seen from FIG. 10, the maximum torque required for MG2 itself is significantly reduced as compared with the case of FIG.

8 to 10, the internal combustion engine (in some cases, internal combustion engine and MG1) and the second motor generator MG are mainly viewed in the coordinate system of vehicle speed versus axle torque as described above.
2 is a performance characteristic diagram showing the amount of torque that can be covered by 2 with respect to vehicle speed, and is not a gear shift diagram in such a hybrid vehicle drive structure with a transmission. That is, FIG.
In the embodiment of FIG. 5, even when the demand for the axle torque is low, as the vehicle speed increases from the low vehicle speed to the high vehicle speed, the transmission always has the first speed, the second speed, and the third speed. It does not mean that it is possible to switch to a tier. In these embodiments, when a high axle torque is not required, which is the case when the vehicle is normally started on level ground, the transmission is set to the third speed and the power distribution mechanism is controlled to control the region shown in FIG. B, the second speed and the first speed are
Each may be used when the required axle torque increases or when the shift lever is switched to the 2 position and the L position.

In any of the above embodiments,
Driving the vehicle in the reverse direction is to make Nr a negative value as seen in FIG. 2, regardless of whether the internal combustion engine is operating (Nc> 0) or not (Nc = 0).
This is achieved by adjusting the rotation speed Ns of MG1 and the rotation speed Nr of MG2 according to the internal combustion engine rotation speed Nc so that the rotation speed Nr of 2 becomes a desired negative value. Such MG
The adjustment control of the rotational speeds of 1 and MG2 can be performed rapidly without any step, but in this case, the torque for driving the vehicle in the reverse direction can be covered only by the motor-generator, so the magnitude of the reverse drive torque obtained is Limited On the other hand, when the transmission is provided in the middle of the wheel drive shaft and has a reverse gear as in the embodiment shown in FIG. 4 or 5, this is switched to the reverse gear and the wheels are driven backward by the internal combustion engine. By doing so, although it takes some time to switch the transmission, the vehicle can be driven in reverse with a large driving torque. Therefore, although not shown in the figure, if a means for selecting between the vehicle reverse drive by the reverse gear of the transmission and the vehicle reverse drive by adjusting the power distribution mechanism is provided, the vehicle reverse drive is required. A more appropriate vehicle operation can be performed by appropriately selecting between the two according to the magnitude of the driving torque. The means for making such a selection can be achieved almost by software according to the vehicle operation control device equipped with the current computer.

In the above, the present invention has been described in detail with reference to several embodiments, but the present invention is not limited to these embodiments, and various other implementations are possible within the scope of the present invention. It will be apparent to those skilled in the art that examples are possible.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a drive structure of a hybrid vehicle to be improved by the present invention.

2 is a rotational speed N of an internal combustion engine and two motor generators MG1 and MG2 in the hybrid vehicle drive structure shown in FIG.
A diagram showing the relationship between c, Ns, and Nr.

3 is a diagram showing an axle torque to be shared by each of an internal combustion engine and a motor generator MG2 with respect to a vehicle speed in the hybrid vehicle drive structure shown in FIG.

FIG. 4 is a schematic diagram showing a first embodiment of an improvement made by the present invention with respect to the hybrid vehicle drive structure shown in FIG.

FIG. 5 is a schematic view showing a second embodiment of the improvement made by the present invention with respect to the hybrid vehicle drive structure shown in FIG.

6 is a schematic view showing a third embodiment of the improvement made by the present invention with respect to the hybrid vehicle drive structure shown in FIG.

FIG. 7 is a schematic diagram showing an example of a transmission that provides three shift speeds and a reverse speed.

8 is a diagram showing an axle torque to be shared by an internal combustion engine and a motor generator MG2 with respect to a vehicle speed in the hybrid vehicle drive structure shown in FIG.

9 is a diagram showing an axle torque to be shared by an internal combustion engine and a motor generator MG2 with respect to a vehicle speed in the hybrid vehicle drive structure shown in FIG.

10 is a diagram showing an axle torque to be shared by an internal combustion engine and a motor generator MG2 with respect to a vehicle speed in the hybrid vehicle drive structure shown in FIG.

[Explanation of symbols]

1 ... Internal combustion engine 2 ... Output shaft of internal combustion engine 3 ... Planetary gear device 4 ... Sun gear 5 ... Ring gear 6 ... Planetary pinion 7 ... Career 8 ... First motor generator (MG1) 9 ... Coil 10 ... rotor 11 ... Propeller shaft 12 ... Second motor generator (MG2) 13 ... Coil 14 ... rotor 15, 16 ... Gears 17 ... Differential device 18 ... Axle 19 ... Wheels 20 ... Sun gear 22 ... Ring gear 24 ... Planetary pinion 26 ... Career 21 ... Sun gear 23 ... Ring gear 25 ... Planetary pinion 27 ... Career 28, 29 ... Clutch 28, 29 ... Brakes 32 ... One-way clutch 100, 101, 102 ... Transmission

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yutaka Taga             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. F-term (reference) 3D039 AA04 AB27 AC39 AC74                 3J027 FB01 GC13 GC22 GD03 GD04                       GD07 GD09                 5H115 PA12 PG04 PI16 PU01 PU25                       SE08 SF01 TO04 UI40

Claims (5)

[Claims] 1. A hybrid vehicle drive structure in which an output shaft of an internal combustion engine is connected to a first motor generator and a wheel drive shaft via a power distribution mechanism, and a second motor generator is connected to the wheel drive shaft. In the above, the hybrid vehicle drive structure is characterized in that a transmission is provided in at least one of the wheel drive shaft and the second motor generator connected to the wheel drive shaft. 2. The hybrid vehicle according to claim 1, wherein the transmission is provided in the middle of the wheel drive shaft, closer to the internal combustion engine than a connecting portion of the second motor generator. Drive structure. 3. The transmission according to claim 1, wherein the transmission is provided on the side of the wheel drive shaft on a side separated from the internal combustion engine with respect to the connecting portion of the second motor generator. Hybrid vehicle drive structure. 4. The hybrid vehicle drive structure according to claim 1, wherein the transmission includes a reverse gear. 5. The hybrid according to claim 4, further comprising means for selecting between a reverse drive of the vehicle by the reverse gear of the transmission and a reverse drive of the vehicle by adjusting the power distribution mechanism. Car drive structure.