JPH08108769A - Braking energy regenerative device for vehicle - Google Patents

Abstract

PURPOSE: To promote normal rotation of an input shaft on the driving source side by regulating the reverse rotation of the input shaft in a variable displace ment pump and motor source to which a working fluid is supplied in the case where the pressure of the working fluid stored in an accumulator is lowered. CONSTITUTION: In the case of starting or traveling a vehicle with operating oil stored in an accumulator 14, a swash plate 11a is operated to operate a variable displacement pump and motor 11 as a variable displacement motor. One input shaft 4a in a differential gear mechanism 3 is rotated through a transmission 2 by an engine 1, and the other input shaft 4b is rotated by the variable displacement pump motor 11. When the operating oil in the accumulator 14 runs out, the other input shaft 4b is kept from being rotated in the reverse direction by a one-way clutch 15. Accordingly, the engine 1 can rotate only an axle 10 efficiently without operating the variable displacement pump and motor 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a braking energy regeneration system for a vehicle, and more particularly, when a vehicle is stopped from a running state, a variable displacement pump / motor is used as a variable displacement pump to store a working fluid in an accumulator, The present invention relates to a braking energy regeneration device for a vehicle, which assists traveling of a vehicle by rotating a variable displacement pump / motor as a variable displacement motor by a working fluid when starting or traveling.

[0002]

2. Description of the Related Art A conventional vehicle braking energy regeneration device is shown in FIG. Engine 61 for running a vehicle (not shown)
Is connected to the drive shaft 63 via the first clutch 62. The drive shaft 63 is connected via a transmission 64 to a differential 65 that rotates wheels (not shown). Further, a connecting gear 66 is provided on the drive shaft 63 so as to be integrally rotatable. A drive gear 67 is meshed with the connecting gear 66. The drive gear 67 is connected to a variable displacement pump / motor 69 via a second clutch 68.

By switching the swash plate 70 provided on the variable displacement pump / motor 69, the variable displacement pump / motor 6
9 can be used as a pump or a motor.
An accumulator 71 is connected to the variable displacement pump / motor 69 via a valve 72. The accumulator 71 stores the hydraulic oil pumped when the variable displacement pump / motor 69 is used as a pump by switching the swash plate 70.

When the vehicle is stopped from the running state, the first clutch 6 is controlled by a control device (not shown).
2 is separated. At this time, the control device operates the swash plate 70 of the variable displacement pump / motor 69 to operate as a pump. Then, the inertial rotation of the drive shaft 63 is transmitted to the variable displacement pump / motor 69 via the coupling gear 66, the drive gear 67, and the second clutch 68. for that reason,
The variable displacement pump / motor 69 pumps up the hydraulic oil and stores the differential oil in the accumulator 71. Further, the variable displacement pump / motor 69 becomes a load, the rotation of the drive shaft 63 is stopped, and the vehicle is stopped.

Next, when the vehicle is started from the stopped state, the second clutch is released with the first clutch 62 disengaged.
The clutch 68 is connected. Then, the control device operates the swash plate 70 to operate the variable displacement pump motor 69 as a motor. Then, the hydraulic oil stored in the accumulator 71 causes the variable displacement pump / motor 69 to move.
And the drive gear 67 rotates. The rotation of the drive gear 67 is transmitted to the connecting gear 66 and the axle 63 rotates. Then, the pressure of the hydraulic oil in the accumulator 71 drops,
When the torque of the variable displacement pump / motor 69 decreases, the second clutch 68 is disengaged. Then, the second clutch 62 is connected and the engine rotates the axle 63. Therefore, the vehicle can be started by the pressure of the hydraulic oil of the accumulator 71, and the load on the engine 61 can be reduced.

[0006]

By the way, when the variable displacement pump / motor 69 operates as a motor to assist the rotation of the drive shaft 63, the accumulator 71 will eventually come out.
The operating oil pressure will be less than the minimum operating pressure. In this case, the swash plate 70 is controlled by a control device (not shown).
Is required to be upright, and the discharge amount of the hydraulic oil discharged from the variable displacement pump / motor 69 needs to be zero.

However, in this state, the engine 6
1 and the variable displacement pump / motor 69 are mechanically connected. Therefore, the engine 61 must rotate the drive shaft 63 and the variable displacement pump / motor 69. At this time, the variable displacement pump / motor 69 does not pump up or discharge the hydraulic oil. However, since the engine 61 operates the variable displacement pump / motor 69, there is a problem that mechanical loss occurs and the efficiency of the engine 61 deteriorates.

As a countermeasure against this, it is possible to disengage the second clutch 68 when the pressure of the hydraulic oil in the accumulator 71 becomes equal to or lower than the minimum operating pressure. However, in this case, a device and a control for connecting and disconnecting the second clutch 68 are required, which causes a problem that the entire device becomes large. Further, when the second clutch 68 is disengaged or engaged, there is a problem that a shock is generated.

Further, when the second clutch 68 is disengaged and the first clutch 62 is engaged, a complicated operation is required in which the rotation of the axle 63 and the rotation of the engine 61 must be synchronized.

Further, there is a demand to efficiently operate the variable displacement pump / motor as a variable displacement pump when the vehicle is decelerated or stopped due to deceleration. The present invention has been made to solve the above problems, and a first object of the present invention is to regenerate braking energy for a vehicle in which a drive source efficiently drives a drive shaft even when the working fluid stored in the accumulator runs out. To provide a device.

A second object is, in addition to the first object, to provide a braking energy regenerative device for a vehicle which has a simple structure and which does not cause a shock without synchronization.

A third object of the present invention is to provide a braking energy regenerative device for a vehicle which efficiently operates a variable displacement pump / motor and stores a working fluid in an accumulator.

[0013]

In order to solve the above problems, according to the invention of claim 1, drive gears respectively provided on a pair of input shafts, and a pinion meshed with the drive gears, A differential gear mechanism including a transmission gear that rotatably supports the pinion, a drive source connected to the one input shaft, and a variable displacement pump / motor connected to the other input shaft, The variable displacement pump / motor is a variable displacement pump, and an accumulator that stores the working fluid pumped up by the variable displacement pump / motor, a drive shaft of a vehicle connected to the transmission gear, and the other input shaft are integrated. The gist of the present invention is to include a rotation restricting mechanism that rotates only in the direction.

According to the second aspect of the invention, the gist is that the rotation restricting mechanism is a one-way clutch that rotates the other input shaft in only one direction. According to a third aspect of the invention, the gist of the invention is to provide a brake mechanism for generating torque on one of the input shafts when the vehicle is decelerated.

[0015]

According to the first aspect of the present invention, the variable displacement pump / motor is a variable displacement pump, the variable displacement pump / motor is operated by inertial rotation of the drive shaft of the vehicle, and the working fluid is pumped up to the accumulator. The vehicle is stopped while being stored. Next, while the vehicle is starting or running, one input shaft of the differential gear mechanism is rotated by the drive source, and the other input shaft of the differential gear mechanism is used as the variable displacement pump / motor as the variable displacement motor. Rotate in one direction.

Then, when the differential gear mechanism operates so that the torques of the one input shaft and the other input shaft become equal, and when the torques of the one input shaft and the other input shaft become equal,
The rotation speeds of the pair of input shafts are in a steady state, the transmission gears rotate, and the drive shaft of the vehicle rotates. Therefore, the drive shaft of the vehicle is assisted by the variable displacement pump motor to rotate.

When the pressure of the working fluid stored in the accumulator becomes low, the variable displacement pump / motor stops and the rotation of the other input shaft stops. At this time, due to the characteristics of the differential gear mechanism, the other input shaft tries to rotate in the opposite direction (the other direction) to the rotation direction of the one input shaft. However, due to the rotation restricting mechanism, the other input shaft does not rotate in the opposite direction and is in a stopped state. Therefore, the torques of the one input shaft and the other input shaft become equal, the transmission gear rotates, and the drive shaft of the vehicle rotates. Therefore, the drive shaft rotates only by the drive source.

According to the second aspect of the invention, since the rotation restricting mechanism for rotating the other input shaft in only one direction is a one-way clutch, it is possible to restrict the rotation of the other input shaft with a simple structure. Becomes

According to the third aspect of the invention, one input shaft is provided with a brake mechanism, and when the vehicle is decelerated or stopped due to deceleration, the brake mechanism regulates the rotation of the one input shaft to generate torque. Let Therefore, when the vehicle is decelerated or stopped by deceleration, the variable displacement pump / motor is used as a variable displacement pump, and the brake mechanism regulates the rotation of one of the input shafts to generate torque.

Then, since the same torque as the torque generated in one input shaft is generated in the other input shaft by the differential gear mechanism, the variable displacement pump / motor can be efficiently operated to store the working fluid in the accumulator. Is possible.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment embodying the present invention is shown in FIG.
A description will be given based on FIG. As shown in FIG. 1, an engine 1 as a drive source mounted on a vehicle (not shown) is connected to a transmission 2. The transmission 2 is an engine 1 using gears.
Decelerate the rotation speed of. The transmission 2 is connected to the differential gear mechanism 3.

A pair of input shafts 4a, 4b constituting the differential gear mechanism 3 face each other, and drive gears 5a, 5b facing each other are provided on the input shafts 4a, 4b.
The drive gears 5a and 5b are provided with pinions 6a and 6b which mesh with each other and face each other. The pinions 6a and 6b are rotatably supported by carriers 7a and 7b.

The carriers 7a and 7b are provided with a ring gear 8 as a transmission gear. The ring gear 8 rotates in a direction orthogonal to the input shafts 4a and 4b. The transmission 2 is connected to one input shaft 4a of the differential gear mechanism 3, and the one input shaft 4a is rotated by the engine 1 via the transmission 2.

A transmission gear 9 is meshed with the ring gear 8. The transmission gear 9 has an axle 10 as a drive shaft.
Is rotatably provided. Wheels are provided on the axle 10 via a differential (not shown). Therefore, when the axle 10 rotates, the wheels rotate through the differential.

A variable displacement pump / motor 11 is connected to the other input shaft 4b. The variable displacement pump / motor 11 is capable of pumping up working oil as working fluid in the oil tank 12. The variable displacement pump / motor 11 is connected via a valve 13 to an accumulator 14 that stores hydraulic oil. Further, the other input shaft 4b is provided with a one-way clutch 15 as a rotation restricting mechanism. The one-way clutch 15 allows the other input shaft 4b only in the direction of the arrow.
Is rotated so that it does not rotate in the direction opposite to the arrow.

The swash plate 1 of the variable displacement pump / motor 11
By operating 1a, the variable displacement pump / motor 11 can be a variable displacement pump or a variable displacement motor. Variable displacement pump / motor 11
When the variable displacement pump / motor 11 is operated by the rotation of the other input shaft 4b in the state where is the variable displacement pump,
The variable displacement pump / motor 11 pumps up the hydraulic oil in the oil tank 12 and stores it in the accumulator 14 via the valve 13. When the variable displacement pump / motor 11 is a variable displacement motor, the variable displacement pump / motor 11 is operated by the hydraulic oil stored in the accumulator 14 to rotate the other input shaft 4b.

Next, various characteristics of the differential gear mechanism 3 will be described. First, for example, one input shaft 4a is rotated by the engine 1, the number of rotations becomes NE, and the torque at that time is TE. Also, variable displacement pump / motor 1
Operate the swash plate 11a of No. 1 and change
Is a variable displacement motor, and the other input shaft 4b is rotated by the hydraulic oil stored in the accumulator 14. The rotation speed of the other input shaft 4b at that time is TN, and the torque at that time is TP. Also, the number of rotations of the axle 10 is ND
And the torque at that time is TD.

The differential gear mechanism 3 operates so that the torque TE of one input shaft 4a and the torque TP of the other input shaft 4b are always equal. For example, the rotational speeds of the input shafts 4a and 4b are NE = NP, and the torque at that time is TE = T.
In the case of P, the pair of pinions 6a and 6b do not rotate, and the ring gear 8 is rotated by the drive gears 5a and 5b via the pinions 6a and 6b and the carriers 7a and 7b. Actually, since the output characteristics of the engine 1 and the variable displacement pump / motor 11 change, TE = TP, NE =
It rarely becomes NP, and when TE = TP, it is general that NE ≠ NP.

Basically, the differential gear mechanism 3 includes the input shafts 4a, 4
The torque of b is operating so that TE = TP. However, it is assumed that the output characteristics of the engine 1 and the variable displacement pump / motor 11 change and the torque becomes TE> TP. Then, the rotations of the pinions 6a and 6b themselves in the differential gear mechanism 3 increase the rotation speed NE of the one input shaft 4a and decrease the rotation speed NP of the other input shaft 4b. Then, when the torques of the input shafts 4a and 4b become equal, the rotational speeds NE and NP of the input shafts 4a and 4b become steady.

Similarly, it is assumed that the output characteristics of the engine 1 and the variable displacement pump / motor 11 change and the torque becomes TE <TP. Then, the rotations of the pinions 6a and 6b themselves in the differential gear mechanism 3 decrease the rotation speed NE of the one input shaft 4a and increase the rotation speed NP of the other input shaft 4b. Then, when the torques of the input shafts 4a and 4b become equal, the rotational speeds NE and NP of the input shafts 4a and 4b become steady.

The torque TD of the axle 10 is TD = TE
It becomes + TP. The rotation speed ND of the axle 10 is ND
= (NE + NP) / 2. Further, the other input shaft 4a
If the rotation in the arrow direction of is considered positive, the rotation in the opposite direction is negative. However, since the other input shaft 4b does not rotate in the direction opposite to the arrow by the one-way clutch 15, the rotation speed ND satisfies the condition of ND ≧ 0.

Then, the swash plate 11a of the variable displacement pump / motor 11 is operated to make the variable displacement pump / motor 11 a variable displacement pump. In this state, when the vehicle is decelerated or stopped by deceleration, the rotation of the axle 10 causes the transmission gear 9,
Ring gear 8, carriers 7a, 7b, pinions 6a, 6
It is transmitted to the input shafts 4a and 4b via b and the drive gears 5a and 5b.

Therefore, the variable displacement pump / motor 11 pumps up the hydraulic oil in the oil tank 12 and stores it in the accumulator 14 via the valve 13. Further, the variable displacement pump / motor 11 becomes a load, and the vehicle is decelerated or stopped by deceleration.

Next, the operation of the device configured as described above will be described. First, when the gear ratio of the transmission 2 is changed and the vehicle is decelerated or stopped by deceleration while the vehicle is traveling, the variable displacement pump / motor 11
The swash plate 11a is operated to form a variable displacement pump. Then, the rotational speed NP is set by the differential gear mechanism 3 so that a torque TP equal to the torque TE generated on the one input shaft 4a by the deceleration of the transmission 2 is generated on the other input shaft 4a.

By rotating the other input shaft 4a, the variable displacement pump / motor 11 pumps up the working oil from the oil tank 12 and stores it in the accumulator 14 via the valve 13. Further, the variable displacement pump / motor 11 becomes a load, and the vehicle smoothly decelerates or stops due to deceleration.

When the vehicle is started or traveling with the hydraulic oil stored in the accumulator 14, the swash plate 11a of the variable displacement pump / motor 11 is operated to change the variable displacement pump / motor 11. Use a capacity motor. In this state, the engine 1 rotates one input shaft 4a of the differential gear mechanism 3 via the transmission 2, and the variable displacement pump / motor 11 is operated by the hydraulic oil stored in the accumulator 14 and the other The input shaft 4b is rotated.

Here, as shown in FIG. 2, the rotational speed NE of one input shaft 4a is NE1, the torque TE is TE1, the rotational speed NP of the other input shaft 4b is NP1, and the torque TP is TP1. , The torque of the input shafts 4a, 4b is TE1> T
It is assumed that P1 is reached.

Then, the differential gear mechanism 3 has the input shafts 4a, 4
In order to equalize the torque of b, the differential gear mechanism 3
The pinions 6a and 6b revolve while revolving. Therefore, the rotation speed of the one input shaft 4a increases and the rotation speed of the other input shaft 4b decreases. The torque decreases as the number of rotations of one input shaft 4a increases, and the torque of the other input shaft 4b increases.
The torque increases as the number of rotations decreases.

When the respective torques of the input shafts 4a and 4b become T0 and become equal, the respective input shafts 4a and 4b become equal.
The rotation speeds of a and 4b are in a steady state. At this time, the rotation speed of one input shaft 4a becomes NE = NE2, and the rotation speed of the other input shaft 4b becomes NP = NP2. This input shaft 4
The torques a and 4b are transmitted to the axle 10 in a state of being added, and the torque TD is TD = 2T0. The rotation speed ND of the axle 10 is ND = (NE2 + ND2) / 2.

The torque of the input shafts 4a and 4b is TE1 <
When TP1 is reached, the rotation speed of the input shaft 4a decreases, the rotation speed of the input shaft 4b increases, and the torque becomes equal.

After that, when the pressure of the hydraulic oil of the accumulator 14 decreases and the torque of the variable displacement pump / motor 11 decreases, the rotational speed of the other input shaft 4b is further decreased to increase the torque. At this time, since one input shaft 4a is rotating by the engine 1, the other input shaft 4b is in a direction opposite to the rotation direction of the one input shaft 4a because of the characteristic of the differential gear mechanism 3, that is, the arrow. And try to rotate in the opposite direction. However, the one-way clutch 15 restricts the other input shaft 4b from rotating in the direction opposite to the arrow. Further, due to this regulation, torque equal to that of the one input shaft 4a is generated in the other input shaft 4b.

Therefore, the rotation of one of the input shafts 4a causes the ring gear 8 to rotate via the pinions 6a and 6b and the carriers 7a and 7b. The rotation of the ring gear 8 is transmitted by the transmission gear 9
Is transmitted to the axle 10 via. Therefore, all the outputs of the engine 1 can be transmitted to the axle 10 via the differential gear mechanism 3.

Therefore, when the hydraulic oil is stored in the accumulator 14, the swash plate 11a is operated to make the variable displacement pump / motor 11 a variable displacement motor, and the other input shaft 4b is rotated to rotate the axle 10. Can be rotated by the engine 1 and the variable displacement pump / motor 11. As a result, the rotation of the axle 10 can be assisted by the variable displacement pump / motor 11, so that the vehicle can be started or run with a small output of the engine 1, and the fuel consumption of the engine 1 can be improved. .

Even when the hydraulic oil in the accumulator 14 is exhausted, the one-way clutch 15 can prevent the other input shaft 4b from rotating in the direction opposite to the arrow. As a result, the engine 1 can rotate only the axle 10 without operating the variable displacement pump / motor 11 via the differential gear mechanism 3. Therefore, the output of the engine 1 can be efficiently transmitted to the axle 10, so that the engine 1 can efficiently drive the vehicle.

Further, even if the variable displacement pump / motor 11 cannot be operated because the hydraulic oil in the accumulator 14 is exhausted, the clutch for connecting / disconnecting the other input shaft 4b and the variable displacement pump / motor 11 is connected. There is no need to provide. As a result, not only the structure of the entire device is simplified, but also control for connecting and disconnecting the clutch is not required, and the handling and the structure of the device can be simplified.

Further, it is not necessary to provide a clutch, and the variable displacement pump / motor 11 is always connected to the other input shaft 4b. As a result, it is possible to eliminate the shock that occurs when connecting and disconnecting the clutch, and it is possible to improve the riding comfort of the vehicle.

Further, a one-way clutch 15 is provided so as not to rotate the other input shaft 4b in the direction opposite to the arrow. As a result, the device itself can be made compact, and the other input shaft 4b can be rotated only in one direction (arrow direction) with a simple configuration. Further, in addition to the one-way clutch 15, the following configuration is possible. A disc is provided on the other input shaft 4b, and a brake device is provided to hold the disc and prevent it from rotating.

Only when the hydraulic oil in the accumulator 14 is exhausted and the variable displacement pump / motor 11 cannot operate, the brake device holds the disc and prevents it from rotating. With this configuration,
It is possible to prevent the other input shaft 4b from rotating in the direction opposite to the arrow.

Further, as shown in FIG. 3, one input shaft 4a
A plate 20 that constitutes a brake mechanism is provided on the plate, and a regulating device 21 that constitutes a brake mechanism that grasps the plate 20 and regulates the rotation thereof is provided. The regulation device 21 grips the plate 20 and increases the driving torque of the input shaft 4a when the vehicle is decelerated or stopped due to deceleration.

Therefore, when the plate 20 is grasped by the regulating device 21 when the vehicle is decelerated or stopped due to deceleration, the torque of the one input shaft 4a increases. Then, the differential gear mechanism 3 also generates an equal torque on the other input shaft 4b. With this torque, the variable displacement pump / motor 11
Is operated, and the hydraulic oil in the oil tank 12 is stored in the accumulator 14 via the valve 13.

Therefore, when the vehicle decelerates or stops due to deceleration, more inertial rotation of the axle 10 can be efficiently transmitted to the variable displacement pump / motor 11. As a result, the variable displacement pump / motor 11 can be operated efficiently and the hydraulic oil can be stored in the accumulator 14.

If the transmission is a manual type, the restricting device 21 grasps the plate 20 so as to rotate the plate 20 slightly so that the engine 1 does not stop, and if it is an automatic type, the restricting device does not rotate the plate 20. You may make it grasp by 21.

Although the differential gear mechanism 3 is used in this embodiment, a planetary differential gear mechanism 25 can also be used as shown in FIG. 4 in addition to this. This structure will be briefly described, but the same structures as those in the above-described embodiment are designated by the same reference numerals and detailed description thereof will be omitted.

A first gear 26 as a drive gear is provided on one of the input shafts 4a. A plurality of pinions 27 are arranged on the inner circumference of the first gear 26 at predetermined intervals,
It is meshed with the gear 26. The pinion 27 is rotatably supported by a carrier 28. A second gear 29 as a drive gear that meshes with the pinion 27 is arranged at the center of the pinion 27.

Further, the axle 1 is provided at the center of the carrier 28.
0 is fixed, and the axle 10 is inserted into the second gear 29. Therefore, the second gear 29 is rotatably supported on the axle 10. The second gear 29 has a third gear 3
0s are connected. The third gear 30 is the other input shaft 4b
Is meshed with the fourth gear 31 provided on the. Also in this configuration, the same operational effect as that of the above-described embodiment can be obtained.

In this embodiment, the engine 1 is used as the drive source, but it is also possible to use a motor or the like. Also, although hydraulic oil was used as the working fluid,
In addition to this, it is also possible to use fluids such as air and water.

[0057]

As described in detail above, according to the inventions of claims 1 to 3, the accumulator is operated in a state in which the variable displacement pump / motor operates as a variable displacement motor and assists the rotation of the drive shaft. When the pressure of the working fluid becomes low, the differential gear mechanism tries to rotate the other input shaft in the other direction opposite to the rotation direction of the one input shaft. At this time, rotation in the other direction is restricted by the rotation restriction mechanism, and torque equal to that of the one input shaft is generated in the other input shaft. Therefore, the drive source can rotate only the drive shaft without operating the variable displacement pump / motor.
As a result, the drive source can be efficiently operated and the drive shaft can be efficiently rotated. Further, since it is not necessary to disconnect or connect the variable displacement pump / motor to the drive shaft, the structure is simplified and the overall size of the device can be prevented from increasing. Moreover, it is possible to prevent a shock from occurring due to the operation or stop of the variable displacement pump / motor.

According to the second aspect of the invention, the rotation of the other input shaft in one direction can be restricted by a simple structure.

According to the third aspect of the invention, when the vehicle is decelerated or stopped by deceleration, the variable displacement pump / motor is a variable displacement pump, and the rotation of one of the input shafts is restricted by the brake mechanism to generate torque. Let As a result,
Since the same torque as that of one input shaft is generated in the other input shaft, it is possible to efficiently operate the variable displacement pump / motor and store the working fluid in the accumulator.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a braking energy regeneration device according to the present invention.

FIG. 2 is a characteristic diagram showing an example of torque characteristics with respect to rotation speeds of a pair of input shafts.

FIG. 3 is a configuration diagram showing another example in which a plate is provided on one of the input shafts and a restricting device that holds the plate is provided.

FIG. 4 is a configuration diagram showing another example in which a planetary differential gear mechanism is used instead of the differential gear mechanism.

FIG. 5 is a configuration diagram showing a conventional braking energy regeneration device.

[Explanation of symbols]

1 ... Engine as drive source, 3 ... Differential gear mechanism, 4
a, 4b ... Input shaft, 5a, 5b ... Drive gear, 6a, 6b
... pinion, 8 ... ring gear as transmission gear, 10 ...
Axle as drive shaft, 11 ... Variable displacement pump / motor,
14 ... Accumulator, 15 ... One-way clutch as a rotation restricting mechanism, 20 ... Plate that constitutes the brake mechanism, 21 ... Regulator device that constitutes the brake mechanism, 25
... Differential planetary gear mechanism as differential gear mechanism, 26 ... First gear as drive gear, 29 ... Second gear as drive gear

Claims (3)

[Claims] 1. A differential gear mechanism including drive gears respectively provided on a pair of input shafts, a pinion meshed with the drive gears, and a transmission gear that rotatably supports the pinion, A drive source connected to one input shaft, a variable displacement pump / motor connected to the other input shaft, and the variable displacement pump / motor were used as variable displacement pumps, and pumped by this variable displacement pump / motor. A braking energy regeneration device for a vehicle, comprising: an accumulator for storing a working fluid; a drive shaft of a vehicle connected to the transmission gear; and a rotation restricting mechanism for rotating the other input shaft in only one direction. 2. The braking energy regeneration device for a vehicle according to claim 1, wherein the rotation restricting mechanism is a one-way clutch that rotates the other input shaft in only one direction. 3. The braking energy regeneration device for a vehicle according to claim 1, further comprising a brake mechanism for generating a torque on one of the input shafts when the vehicle is decelerated.