JPH11311312A - Right and left driving force distribution device for vehicles - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reduce the size and weight of the entire device. A cylindrical portion (40) is provided between one side gear (26) and an axle (28) in a differential device (20). The motor housing 35 of the trochoid motor 33 is fixedly installed in the cylindrical portion 40. One side gear 2 is connected to the other side gear 27.
The connecting shaft 41, which is loosely inserted into the center hole 39 of the sixth, extends. The distal end of the connecting shaft 41 is connected to the inner rotor 37 of the trochoid motor 33. The torque of the trochoid motor 33 directly acts on the left and right axles 28 and 29. Since the trochoid motor 33 is arranged at a position distant from the side gears 26, 27, the size of the side gears 26, 27 and the differential pinion 25 can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a left and right driving force distribution device for a vehicle capable of positively controlling the distribution ratio of driving force to left and right wheels.

[0002]

2. Description of the Related Art As this kind of right and left driving force distribution device, a device as shown in FIG. 4 has been proposed.

[0003] This left and right driving force distribution device comprises a differential 1
A hydraulic motor 4 for applying a relative rotational force between the left and right axles 2 and 3 is incorporated therein. By operating the hydraulic motor 4 at the time of turning of the vehicle or the like, the outer wheels 5 (or 6) are A yaw moment is generated in the vehicle by applying a rotational force greater than 6 (or 5).

[0004] Specifically, a differential case 7 which rotates by receiving a driving force from an engine, a differential pinion 8 rotatably supported in the differential case 7, and left and right axles 2, 3
And a pair of side gears 9 and 10 meshed with the differential pinion 8 in the differential case 7 from both right and left sides.
A hydraulic motor 4 such as a trochoid motor is incorporated in the well-known differential device 1 having a motor housing 11 of the hydraulic motor 4 fixed to the differential case 7 and a rotating shaft 12 of the hydraulic motor 4 It is connected to one of the left and right axles 2.

In this case, a hydraulic pump 13 for supplying hydraulic oil to the hydraulic motor 4 is provided between a differential housing 14 fixedly installed in a vehicle and a differential case 7 which rotates by receiving a driving force of an engine. When the rotational force is transmitted from the propulsion shaft 15 to the differential case 7, the differential case 7
The hydraulic oil is discharged with the rotation of. Further, a pressure control valve 18 and a flow path switching valve 19 controlled by a controller 17 are interposed in a hydraulic circuit 16 connecting the hydraulic pump 13 and the hydraulic motor 4, and the supply pressure is adjusted according to the traveling state of the vehicle. The rotation directions of the hydraulic motor 4 and the hydraulic motor 4 are appropriately controlled by these valves 18 and 19.

Incidentally, this similar technique is disclosed, for example, in Japanese Patent Publication No. 7-1.
No. 8481, etc.

[0007]

In the above-mentioned conventional left and right driving force distribution device, the hydraulic motor 4 rotates between the differential case 7 and one of the axles 2 to thereby drive between the left and right axles 2, 3. A force difference is created. Therefore, in the case of the conventional device, the hydraulic motor 4
Are generated by the side gears 9 and 10 of the differential device 1.
By the action of the differential pinion 8, the power is reduced to about half and transmitted to the left and right axles 2 and 3, so that the hydraulic motor 4 must be increased in order to generate the yaw moment required for vehicle control.

As a means for solving this problem, it is conceivable to directly interpose the hydraulic motor 4 between the left and right axles 2 and 3. Side gears 9 and 10 and differential pinion 8 of differential device 1
When the hydraulic motor 4 is disposed in this portion, it is necessary to increase the size of the side gears 9 and 10 and the differential pinion 8 to secure a space for accommodating the hydraulic motor 4. Therefore, even if the size of the hydraulic motor 4 is increased, the size of the entire device is rather increased, and the size and weight of the device cannot be reduced.

Accordingly, an object of the present invention is to provide a left-right driving force distribution device for a vehicle which can further reduce the size and weight of the entire device without causing a problem such as a decrease in performance.

[0010]

Means for Solving the Problems As means for solving the above-mentioned problems, the invention according to claim 1 is a differential case that rotates by receiving a driving force from an engine, and is rotatably supported in the differential case. A differential gear having a pair of side gears respectively coupled to the left and right axles while being engaged with the left and right axles in the differential case, respectively. In a left-right driving force distribution device for a vehicle incorporating a reversible hydraulic motor for applying an effective rotational force, a cylindrical portion is provided between one side gear and an axle on the same side as the side gear. While the motor housing of the hydraulic motor is fixed, a connecting shaft extending through the one side gear is extended to the other side gear, and the end of the connecting shaft is connected to the hydraulic motor. And to bind to the rotary shaft portion.

In the present invention, since the hydraulic motors are directly connected to the left and right axles, the rotational force of the hydraulic motors is directly transmitted to the left and right axles without being reduced by half in the differential device. In addition, the motor housing is housed in the cylindrical portion provided between one side gear and the axle on the same side as the side gear, so a large space for housing the hydraulic motor is secured in the side gear and the differential pinion in the differential case. You don't have to.

Further, in the invention according to claim 2, in the invention according to claim 1, the diameter of the connecting shaft is set smaller than the diameter of the left and right axles. In the case of the present invention, since the connecting shaft only applies the power of the hydraulic motor between the left and right axles, the strength of the connecting shaft is insufficient even if the diameter of the connecting shaft is set smaller than the diameter of the left and right axles. Does not occur.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG.

FIG. 1 is a schematic structural view of this embodiment.
In the figure, reference numeral 20 denotes a differential of a vehicle. This differential device 20
Is basically the same as that of the well-known one, and the rotational force of the propulsion shaft 21 connected to the engine (not shown) is transmitted to the differential case 24 by the drive pinion 22 and the ring gear 23.
To the left and right axles 2 by the differential pinion 25 and the side gears 26, 27.
8, 29, and the rotation of the differential pinion 25 absorbs the difference in the rotational speeds of the left and right axles 28, 29. That is, the differential case 24 is rotatably supported by a differential housing 30 fixedly installed on the vehicle body, and a differential pinion 25 is rotatably supported on a central inner wall of the differential case 24. A pair of side gears 26, 27 connected to the respective axles 28, 29 are meshed from both sides thereof.
In addition, in the figure, 31 and 32 are wheels connected to the tip of each axle 28 and 29.

In the right and left driving force distribution device of this embodiment, a trochoid motor 33 as a hydraulic motor for applying a relative rotational force between the left and right axles 28 and 29 is incorporated in the differential device 20. In addition, a trochoid pump 34 as a hydraulic pump that generates hydraulic pressure by rotation of the differential case 24 is incorporated.

As shown in FIG. 2, the trochoid motor 33 has a motor housing 35 in which an outer rotor 36 and an inner rotor 37 are rotatably accommodated, and is formed between inner teeth of the outer rotor 36 and outer teeth of the inner rotor 37. Port P ₁ for supplying high pressure hydraulic oil to the liquid chamber 38
And (P _2), the port P ₂ for discharging hydraulic fluid from the fluid chamber 38 in the opposite (P ₁₎ is opened and formed at predetermined positions of the side surface of the motor housing 35. The two ports P ₁ and P ₂ are formed at positions where _one port P ₁ (or P ₂ ) functions as a supply port and the other port P ₂ (or P ₁ ) forms a discharge port. I have. The direction of rotation of the outer rotor 36 and inner rotor 37 is adapted to be switched to A ₁ direction or A ₂ direction in the figure by or supplying hydraulic oil to one of the ports P _1, P _2.
In the following description, the port on the right side in FIG. ₂ is referred to as a first port P ₁ and the port on the left side is referred to as a second port P ₂ for convenience of description.

As shown in FIG. 1, a center hole 39 is formed in one side gear 26, and a cylindrical portion 40 communicating with the center hole 39 is formed between the side gear 26 and the axle 28. Have been. A motor housing 35 of the trochoid motor 33 is fitted and fixed in the cylindrical portion 40, and a connection shaft 41 coaxially extended with the other side gear 27 is loosely inserted into a center hole 39 of the side gear 26.
The distal end of the connecting shaft 41 is connected to the inner rotor 37, which is the rotating shaft of the trochoid motor 33, in the tubular portion 40. Therefore, when the trochoid motor 33 receives the supply hydraulic pressure and rotates in either the forward or reverse direction, the rotational force acts directly between the left and right axles 28 and 29.
Note that the connecting shaft 41 causes the torque of the trochoid motor 33 to act between the left and right axles 28 and 29 and is smaller than the torque of the propulsion shaft 21. Is smaller than the diameter. Therefore, the differential device 20 can be compactly incorporated into the differential device 20, and there is no need to increase the size of the differential device 20.

On the other hand, the trochoid pump 34 has an outer rotor 4 inside a pump housing 42 as shown in FIG.
4 and the inner rotor 43 are rotatably housed,
The suction port P ₃ faces the pump chamber 45 formed between the inner teeth of the outer rotor 44 and the outer teeth of the inner rotor 43.
Discharge port P ₄ is opened and formed at predetermined positions of the side surface of the pump housing 42 and. In the trochoid pump 34, as shown in FIG. 1, the pump housing 42 is fitted and fixed to the differential housing 30, and the inner rotor 43 is fitted and fixed to the right side outer peripheral surface of the differential case 24. Thus, the inner rotor 43 and outer rotor 44 is the direction of arrow B (see FIG. 2.) With the rotation of the differential case 24 rotates, the external hydraulic fluid encased sucked from the suction port P ₃ to the pump chamber 45 from the discharge port P ₄ Is discharged.

The trochoid pump 34 and the trochoid motor 33 are connected through a hydraulic circuit 48 having a pressure control valve 46 and a flow path switching valve 47.

That is, the suction port P ₃ of the trochoid pump 34 is connected to a reservoir 49 for storing hydraulic oil, and the discharge port P ₄ is connected to the ports P ₁ and P _{2 of} the trochoid motor 33 via the flow path switching valve 47. The discharge port P ₄ is connected to one of the reservoirs 49 by switching.
In the middle of the connection path between the flow path switching valve 47 and the
A pressure control valve 46 for appropriately opening and closing the drain passage 51 by the control of 0 is interposed. The flow path switching valve 47 is configured by a four-port three-position switching valve that is switched and controlled by the controller 50, and one of the following first, second, and third switching states is obtained according to the switching position. It has become. The four ports of the flow path switching valve 47
A discharge-side port P ₁₄ is connected to the discharge port P ₄ of the trochoid pump 34, the suction-side port P ₁₃ is connected to the suction port P ₃ of the pump 34, the first port P ₁ of the trochoid motor 33 second The first and the first connected to the port P _{2 respectively} .
It is constituted by the second input / output ports P ₁₁ and P ₁₂ .

[0021] First switching state] FIG. 1, the switching state in which through the discharge side port P ₁₄ and the intake side port P _13, a first input and port P ₁₁ of the second input and port P ₁₂ respectively communicating, as shown in FIG. 2 .

[0022] Second switching state] discharge side port P ₁₄ and the first input and port P _11, switching state to the suction side port P ₁₃ of the second input and port P ₁₂ respectively communicated.

[0023] [Third switching state] discharge side port P ₁₄ and the second input and port P _12, switching state to the suction side port P ₁₃ of the first input and port P ₁₁ communicate respectively with each other.

Further, the controller 50 controls the vehicle speed, the steering angle,
Receiving signals such as lateral G as input signals, and appropriately controlling the pressure control valve 46 and the flow path switching valve 47 based on these signals,
Thereby, the distribution of the right and left driving forces is adjusted.

Further, since the motor housing 35 of the trochoid motor 33 rotates integrally with the axle 28, a rotary joint 52 is interposed in the oil passage connecting the flow path switching valve 47 and the trochoid motor 33. .

As shown in FIG. 3, the rotary joint 52 includes an outer ring 53 fixed inside the cylindrical portion 30a of the differential housing 30, an inner ring 54 fixed to the outer peripheral surface of the left axle 28, and both rings. Seal ring 57 forming a pair of annular passages 55, 56 between 53, 54
When first the annular passage 55, 56 and trochoid motor 33, connecting channel 58,5 the second port P _1, P ₂ are respectively connected
9, and the outer ring 53 includes a flow path switching valve 4.
7, the first and second inlet / outlet ports P ₁₁ and P ₁₂ and the respective annular passages 5
Connection paths 60 and 61 for connecting 5, 56 are formed. Therefore, the first and second ports P ₁ and P ₂ of the trochoid motor 33 are always connected to the first and second input / output ports P ₁₁ and P ₁₂ of the flow path switching valve 47 regardless of the rotation state of the axle 28. Will be maintained.

Next, the operation will be described.

The flow path switching valve 47 is the first type as shown in FIGS.
When there in the switching state, the intake side port P ₁₂ and the working fluid discharged from the trochoid pump 34 is the discharge side port P ₁₁
The trochoid motor 33 is returned to the suction port P ₃ (or the reservoir 49) of the trochoid pump 34, and the trochoid motor 33 is in a state where free rotation is possible because the first and second inlet / outlet ports P ₁₁ and P ₁₂ are connected to each other. Has become. Therefore, at this time, the side gears 2 on both sides of the differential 20
The rotational force of the trochoid motor 33 is not applied between the left and right axles 2 and 6 through the differential device 20 from the propulsion shaft 21.
A driving force equal to 8, 29 is transmitted.

[0029] Then, when the flow path switching valve 47 by the control signal of the controller 50 in this state is switched to the second switching state, the discharge side port P ₁₄ first input and port P _11, and the intake side port P ₁₃ second 2 and out port P ₁₂ is in communication s communicating respectively, the inner rotor 37 and outer rotor 36 of a trochoid motor 33 is to rotate in the a ₁ direction (see FIG. 2.) to the motor housing 35. At this time, the motor housing 35 passes through the cylindrical portion 40 and the left axle 2
8, since the inner rotor 37 is connected to the right axle 29 through the connecting shaft 41, the trochoid motor 3
The torque of 3 directly acts between the left and right axles 28 and 29 to generate a rotation difference. As a result, the left axle 28 is decelerated while the right axle 29 is accelerated, and the driving force of the propulsion shaft 21 is increased according to the rate of the increase and deceleration.
9 are allocated.

The flow path switching valve 47 is connected to the controller 50.
When switched into the third switching state by the control signal of the discharge side port P ₁₄ and the second input and port P _12, the suction-side port P ₁₃ and the first input and port P ₁₁ is in communication s communicating respectively, trochoid motor inner rotor 37 and outer rotor 36 of the 33 is to rotate in the a ₂ direction (see FIG. 2.) to the motor housing 35. As a result, the speed of the left axle 28 is increased while the right axle 29 is increased.
Is decelerated, and the driving force of the propulsion shaft 21 is distributed to the left and right axles 28 and 29 at a rate corresponding to the acceleration / deceleration.

In both the second switching state and the third switching state, the rate of acceleration / deceleration of the left and right axles 28, 29 is appropriately controlled by adjusting the pressure of the supplied hydraulic oil by the pressure control valve 46. You.

In this left-right driving force distribution device, a motor housing 35 of a trochoid motor 33 is fixedly installed in a cylindrical portion 40 provided between a left side gear 26 and an axle 28,
The connecting shaft 41 extended from the right side gear 27 is passed through the center hole 39 of the left side gear 26 to form the inner rotor 37.
, The torque of the trochoid motor 33 is applied directly between the left and right axles 28 and 29, so that the torque of the trochoid motor 33 is not reduced to half by the differential device 20. Therefore, in this left-right driving force distribution device, a sufficiently large yaw moment required for vehicle control can be generated without increasing the size of the trochoid motor 33.

Further, in the case of the left and right driving force distribution device, the trochoid motor 33 is arranged not at the position between the left and right side gears 26 and 27 in the differential device 20 but at a position axially offset therefrom. Side gear 2
There is no need to secure a large space between 6 and 27 to accommodate the trochoid motor 33, and as a result,
The size of the side gears 26 and 27 and the differential pinion 25 can be avoided. Therefore, in this driving force distribution device, the size of the motor 33 can be reduced, and further reduction in size and weight of the entire device can be achieved.

The embodiments of the present invention are not limited to those described above. For example, a piston motor other than the trochoid motor may be used as a hydraulic motor for applying a rotational force between the axles 28 and 29. It is possible. Similarly, another type of pump such as a piston pump may be used instead of the trochoid pump for the pump that supplies the hydraulic pressure to the hydraulic motor.

[0035]

As described above, the invention according to claim 1 is
A cylindrical portion is provided between one side gear and the axle on the same side as the side gear, and a motor housing of the hydraulic motor is fixed in the cylindrical portion, while a connecting shaft that penetrates the one side gear is mounted on the other side gear. Since the extension of the connecting shaft is connected to the rotating shaft of the hydraulic motor, a sufficiently large rotating force can be applied between the left and right axles with a small hydraulic motor. Since it is not necessary to secure a large space for accommodating the hydraulic motor in the side gear and the differential pinion portion in the differential case, it is possible to make the entire apparatus smaller and lighter.

According to a second aspect of the present invention, since the diameter of the connecting shaft is set smaller than the diameters of the left and right axles in the first aspect of the present invention, it is not necessary to increase the size of the differential device. The whole can be further reduced in size and weight.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view of the trochoid motor and the trochoid pump of FIG. 1 showing the embodiment.

FIG. 3 is a sectional view of the rotary joint of FIG. 1 showing the embodiment.

FIG. 4 is a sectional view showing a conventional technique.

[Explanation of symbols]

 Reference Signs List 20 differential gear, 24 differential case, 25 differential pinion, 26, 27 side gear, 28, 29 axle, 33 trochoid motor (hydraulic motor), 35 motor housing, 37 inner rotor (rotary shaft), 40 ... cylindrical part, 41 ... connecting shaft.

Claims (2)

[Claims] 1. A differential case which rotates by receiving a driving force from an engine, a differential pinion rotatably supported in the differential case, and coupled to left and right axles, respectively, while being connected to the differential pinion in the differential case from both left and right sides. A left-right driving force distribution device for a vehicle in which a reversible hydraulic motor that applies a relative rotational force between the left and right axles as necessary is incorporated in a differential device having a pair of side gears meshed with each other. In the above, a cylindrical portion is provided between one side gear and an axle on the same side as the side gear, and the motor housing of the hydraulic motor is fixed in the cylindrical portion, and the one side gear penetrates the other side gear. A right and left driving force distribution device for a vehicle, wherein a connecting shaft is extended, and a tip of the connecting shaft is connected to a rotating shaft portion of the hydraulic motor. 2. The vehicle driving force distribution device according to claim 1, wherein the diameter of the connecting shaft is set smaller than the diameter of the left and right axles.