JPH10220557A - Differential gear and clutch device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain stable large differential limiting force by driving a radial piston pump by relative rotation of a cylinder member and a cam member when differential rotation is generated to differential mechanism, and actuating a hydraulic actuator with the delivery pressure to lock a friction clutch. SOLUTION: When differential rotation is generated to differential gear mechanism 39, a pump case 63 and a cam member 73 are relatively rotated, and a radial piston pump 47 is actuated by a cam face 91 of the cam member 73. A radial piston 75 pushed by a protruding part of the cam face 91 at this time is pushed into a cylinder 93, and the radial piston 75 opposed to a recessed part of the cam face 91 is pushed back onto the recessed part side. In the cylinder 93 with the radial piston 75 pushed therein, a discharge side check valve 81 is opened, and in the cylinder 93 with the radial piston 75 pushed back, an intake side check valve 79 is opened. A multiple disk clutch 43 is locked by actuation of a hydraulic actuator 45 to limit operation of operating gear mechanism 39.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a differential device used for a vehicle and a clutch device.

[0002]

2. Description of the Related Art U.S. Pat. S. Patent 5310388
Device 201 as shown in FIG.
Is described.

[0003] The differential device 201 includes a pinion shaft 205 fixed to a differential case 203,
A bevel gear type differential mechanism 213 composed of a pinion gear 207 rotatably supported on a pinion shaft 205, side gears 209 and 211 meshing with the pinion gear 207, a multi-plate clutch 215 for limiting the differential, and a multi-plate clutch 215. Hydraulic actuator 217 for fastening
And a gear pump 219 for operating the hydraulic actuator 217. The side gears 209 and 211 are spline-connected to axles 221 and 223, respectively.

The multi-plate clutch 215 and the gear pump 219 are arranged between the axle 221 on the side gear 209 side and the differential case 203, and the gear pump 219 is connected to the axle 221.
The hydraulic actuator 217 receives the discharge pressure of the gear pump 219 and presses the multi-plate clutch 215 by receiving the differential rotation of the differential mechanism 213.

The differential limiting force is obtained by the frictional resistance of the multi-plate clutch 215 and the pump work of the gear pump 219.
The differential limiting force limits the differential of the differential mechanism 213.

[0006]

However, in the differential device 201, the gear pump 219 is used to generate the oil pressure for limiting the differential.
Reference numeral 19 denotes a set of gear pumps composed of the external gear 225 and the internal gear 227, in addition to a large amount of oil leakage, so that a small amount of oil is discharged and a high discharge pressure cannot be obtained.

[0007] Therefore, a large differential limiting force cannot be obtained, and the kinetic performance of the vehicle cannot be sufficiently improved. In addition, when the differential rotation speed (△ N) is low, the differential limiting function becomes unstable.

Further, the gear pump 219 is easily affected by a change in the oil temperature. If the oil temperature decreases and the viscosity increases, the amount of the sucked oil decreases and the sucked oil cannot be discharged at a sufficient pressure.

To increase the amount of oil to be discharged, it is necessary to increase the width (dimension in the axial direction) of the gear pump 219. However, increasing the width of the gear pump 219 causes the differential device 201 to be larger and heavier. However, in order to avoid increasing the size and weight of the differential device 201, the accommodation space for the multi-plate clutch 215 is reduced and the clutch capacity is reduced, so that the differential limiting force is reduced.

Further, when the rotation direction of the gear pump 219 changes, the suction direction and the discharge direction are reversed. Therefore, in order to obtain the differential limiting force in both forward and backward travel, it is necessary to send oil to the hydraulic actuator 217 in any of the differential rotation directions. It is necessary to arrange a suction check valve and a discharge check valve respectively on both sides.

As described above, in the differential device 201 using the gear pump 219, the check valve mechanism is extremely complicated and the number of parts is large.

Therefore, the present invention is configured such that a built-in oil pump is driven by a differential rotation and a frictional clutch is pressed to obtain a differential limiting force. A differential device that can obtain a stable and large differential limiting force even when the pressure is low, and a built-in oil pump is driven by the relative rotation between the input side and the output side to obtain the transmission force by pressing the friction clutch It is another object of the present invention to provide a clutch capable of obtaining a stable and large transmission force even when the relative rotation speed is low or the oil temperature is low.

[0013]

According to a first aspect of the present invention, there is provided a differential device comprising: a differential case rotatably driven by a driving force of an engine; a differential mechanism for outputting rotation of the differential case via a pair of output side gears; A friction clutch that limits the differential of the mechanism, a radial piston that is movably engaged in a radial direction with a cylinder member fixed to the differential case, and a radial piston that rotates differentially with respect to the differential case and the cam moves the radial piston from the radial inside to the cylinder. A radial piston pump disposed in a space provided in the differential case, and a piston and a cylinder. The cylinder receives the hydraulic pressure of the radial piston pump and presses the friction clutch via the piston. The hydraulic actuator to be fastened and fastened, and the radial piston pump A suction side check valve for sucking in the cylinder, characterized in that a discharge side Chekubarubu flow for discharging the discharge oil of the radial piston pump from the discharge port to the actuator side.

In the differential device according to the first aspect, when a differential rotation occurs in the differential mechanism, the radial piston pump is driven by the relative rotation between the cylinder member and the cam member, and the hydraulic actuator operates by receiving the discharge pressure. Then, the friction clutch is pressed and fastened. Thus,
A differential limiting force is obtained by the friction resistance of the friction clutch and the pump work of the radial piston pump, and the differential of the differential mechanism is limited by the differential limiting force.

Since the work of the pump and the frictional resistance of the friction clutch increase with an increase in the differential rotation speed, the differential limiting function becomes a speed-sensitive type.

Further, unlike the conventional example of FIG. 11 using one set of gear pumps having a large amount of oil leakage, the radial piston pump has a small oil leakage and has a large number of sets of radial pistons and cylinders. A high oil discharge amount and a high discharge pressure are obtained, and the pump work and the engagement force of the friction clutch are enhanced.

In this manner, a large differential limiting force can be obtained, and in particular, a sufficient differential limiting function can be obtained even when the differential rotation speed (△ N) is low, so that the dynamic performance of the vehicle can be sufficiently improved. it can.

Further, the radial piston pump is hardly affected by a change in oil temperature, so that even if the oil temperature falls,
Because a sufficient amount of oil is sucked in and discharged at a high pressure,
In particular, a large differential limiting force can be obtained even when the oil temperature does not rise sufficiently in winter or the like.

Therefore, it is not necessary to increase the size of the pump in order to increase the oil amount and the discharge pressure. Therefore, unlike the conventional example, the differential device is not enlarged and weighted, and the size of the differential device is reduced. Since it is not necessary to reduce the space for accommodating the friction clutch, a decrease in clutch capacity and differential limiting force is prevented.

Further, unlike the gear pump, the radial piston pump does not change the suction direction and the discharge direction even if the rotation direction changes. Therefore, only one suction side check valve and one discharge side check valve are arranged for each cylinder. Thus, the vehicle can obtain the differential limiting force both when moving forward and when moving backward.

In addition, the check valve mechanism has such a small number of parts, has a simple structure, and is low in cost.

According to a second aspect of the present invention, there is provided a clutch device which is disposed in a space provided in a clutch housing, a friction clutch for connecting the cam members disposed inside the clutch housing and a cam member disposed inside the clutch housing, and a clutch member. It consists of a radial piston pump that operates by receiving the relative rotation of the housing and the cam member, a piston and a cylinder,
A hydraulic actuator for receiving the hydraulic pressure of the radial piston pump to the cylinder and pressing and engaging the friction clutch via the piston.

In the clutch device according to the second aspect, when relative rotation occurs between the clutch housing and the cam member,
The radial piston pump is driven, the actuator is actuated by receiving the discharge pressure, the friction clutch is pressed, and the clutch housing and the cam member are connected.

Thus, power is transmitted by the frictional resistance of the friction clutch and the pump work of the radial piston pump.

At this time, when the relative rotational speed increases, the frictional resistance of the friction clutch and the pump work increase, so that the coupling force (transmitted torque) of the clutch device also increases.

In addition, since a large coupling force can be obtained by using a radial piston pump having a small oil leakage and a high discharge pressure, a large power can be transmitted, and even when the input / output relative rotation speed is low, it is sufficient. Power transmission function.

Further, since a high discharge pressure can be obtained by the radial piston pump even when the temperature of the oil is lowered, a large power can be transmitted even when the oil temperature does not rise sufficiently, particularly in winter.

Also, by using a radial piston pump having a high discharge pressure, the clutch device can be made compact and lightweight, and there is no need to reduce the space for accommodating the friction clutch to reduce the size and weight of the device. Is prevented from decreasing.

Further, by using a radial piston pump, power can be transmitted in any rotational direction by a low-cost check valve mechanism with a simple structure and a small number of parts.

According to a third aspect of the present invention, there is provided the clutch device according to the second aspect, wherein the radial piston pump is radially movably engaged with a cylinder member fixed to the clutch housing; When a relative rotation occurs between the radial piston pump and the cam, the cam pushes the radial piston into the cylinder from the radial inside, a suction check valve that sucks oil into the radial piston pump cylinder, and discharges oil from the radial piston pump cylinder And a discharge side check valve which performs the same effect as that of the second aspect.

According to a fourth aspect of the present invention, there is provided the differential device according to the first aspect or the clutch device according to the second or third aspect, wherein the differential rotation or the relative rotation of the cylinder and the cam member of the radial piston pump is performed. A forcible operating means for moving the radial piston along the cam is provided, and an effect equivalent to that of the first or second or third aspect is obtained.

In addition to the above, a forced operation means for moving the radial piston along the cam and forcibly operating the radial piston pump is provided, so that the cylinder and the cam member of the radial piston pump can rotate differentially. The pump pressure is generated immediately after the relative rotation, and in the differential device of the first aspect, the differential limitation is instantaneously performed with the occurrence of the differential rotation, and in the clutch device of the second and third aspects,
When torque is applied, they are instantaneously connected and power is transmitted.

According to a fifth aspect of the present invention, there is provided the differential device or the clutch device according to the fourth aspect, wherein the cam is a cam surface formed on an outer periphery of the cam member, and the forcibly operating means is a cylinder of a radial piston pump. And a biasing member that presses the radial piston against the cam surface from a radially outer side, and has the same effect as the configuration of claim 4.

In addition to this, the use of the urging member for the forcibly operating means makes it possible to construct the apparatus at low cost, and also makes it possible to implement the following structure.

According to a sixth aspect of the present invention, there is provided the differential device or the clutch device according to the fifth aspect, wherein the urging member is bent by receiving the centrifugal force of the radial piston, and the stroke of the cylinder is reduced. And the discharge pressure of the radial piston pump is adjusted to be small, and the same effect as that of the fifth aspect is obtained.

In addition, since the strength of the urging member is adjusted in this manner, when the centrifugal force of the radial piston is received, the urging member bends, the stroke of the radial piston becomes small, and the discharge pressure drops.

Therefore, in the differential device, when the differential rotation speed is greatly increased, it is possible to reduce the differential limiting force to prevent the differential lock, and in the clutch device, when the excessive torque is input. In addition, the coupling force can be reduced to prevent the friction clutch and the driven machine from being damaged.

According to a seventh aspect of the present invention, there is provided the differential device or the clutch device according to the fourth aspect, wherein the cam is a cam groove which opens in the axial direction of the cam member, and the convex portion on the radial piston side has the cam groove. And the projection and the cam groove form a forced operation means for moving the radial piston along the cam groove with the differential rotation of the cylinder and the cam member. The same effect as that of the configuration is obtained.

According to an eighth aspect of the present invention, there is provided the differential device or the clutch device according to any one of the first to seventh aspects, wherein one or both of the suction side check valve and the discharge side check valve are arranged in the circumferential direction. And a plurality of oil ports arranged on the ring member and valve pieces for closing the oil ports, wherein each valve piece is formed integrally with the ring member as a base. The same effect as that of the configuration is obtained.

In addition, since a large number of valve pieces constituting the check valve are formed integrally with the ring member as a base, the number of parts is greatly reduced as compared with the case where each valve piece is formed separately. In addition, since the displacement of each valve piece with respect to the oil port is suppressed, the operation of the check valve is stabilized, and the differential limiting function of the differential device and the power transmission function of the clutch device are stabilized.

According to a ninth aspect of the present invention, there is provided the differential device or the clutch device according to any one of the first to eighth aspects, wherein the differential device or the clutch device is pressed against a discharge-side check valve via a piston of a hydraulic actuator, and the oil is discharged. A biasing member for preventing backflow is provided, and an effect equivalent to the configuration of any of claims 1 to 8 is obtained.

In addition, since the piston of the hydraulic actuator is pressed against the discharge side check valve by the urging member, the backflow of oil flowing from the cylinder of the radial piston pump into the cylinder of the hydraulic actuator is prevented. .

Accordingly, the differential limiting force of the differential device and the coupling force of the clutch device are prevented from lowering, and these operations are stabilized.

According to a tenth aspect of the present invention, there is provided the differential device or the clutch device according to any one of the first to ninth aspects, wherein the differential device or the clutch device is disposed between the piston of the hydraulic actuator and the discharge side check valve. And a biasing member that presses the side check valve to prevent reverse flow of oil and that applies an initial torque to the friction clutch via a piston is provided. Get the same effect.

In addition, by disposing the urging member between the piston of the hydraulic actuator and the discharge-side check valve, the discharge-side check valve is pressed to prevent the oil from flowing backward, and to prevent the hydraulic actuator from rotating. The friction clutch receives an initial torque by being pressed through the piston.

In addition to the effect of preventing the backflow of oil, this initial torque improves the running stability of the vehicle during acceleration or on a rough road in a differential device, and enables transmission of an extremely small torque in a clutch device. .

According to an eleventh aspect of the present invention, there is provided the differential device or the clutch device according to any one of the first to tenth aspects, wherein the radial piston is provided with a protruding portion, and the protruding portion is sucked in the compression step. It is characterized by being arranged to protrude to the port and discharge port side,
An effect equivalent to that of any one of the first to tenth aspects is obtained.

In addition, since the projecting portion provided on the radial piston reduces the oil capacity of the cylinder, a large discharge pressure can be obtained with a small amount of oil in each cylinder, and the frictional resistance of the friction clutch and the pump of the radial piston pump can be improved. The differential limiting force of the differential device due to the work and the clutch capacity of the clutch device are increased accordingly.

[0049]

1 to 6 show a first embodiment of the present invention.
An embodiment will be described. This embodiment corresponds to claims 1, 4,
FIG. 1 shows a differential device 1 according to this embodiment. Note that the left and right directions are the left and right directions in FIG. 1, and the members and the like without reference numerals are not shown.

As shown in FIG. 1, the differential case 3 of the differential device 1 is configured by fixing a casing main body 5 and a cover 7 with bolts 8. A seal ring 9 is arranged between the casing body 5 and the cover 7 to prevent oil leakage. The differential case 3 is disposed inside the differential carrier, and an oil reservoir 10 is formed in the differential carrier.

The left and right boss portions 11, 12 of the differential case 3 are supported by differential carriers via bearings. A ring gear is fixed to the differential case 3 with bolts,
This ring gear meshes with the drive gear of the drive force transmission system. Thus, the differential case 3 is rotationally driven by the driving force of the engine via this driving force transmission system.

Helical oil grooves 13 and 14 are provided on the inner periphery of each of the boss portions 11 and 12 to guide oil into the inside as the differential case 3 rotates.

As shown in FIG. 2, four pinion shafts 17 are fixed radially around the ring-shaped boss 15 inside the differential case 3. The chamfered portion 19 formed at the outer end of each pinion shaft 17 engages with the groove 21 of the differential case 3 and is connected in the rotation direction. A pinion gear 23 is rotatably supported on each pinion shaft 17.

Left and right output side gears 25 and 27 are disposed inside the differential case 3. Left side gear 2
5 is welded to the boss 29 and the right side gear 27
Are formed integrally with the boss 31. Each side gear 2
5 and 27 are spline-connected to the left and right axles via respective bosses 29 and 31, respectively, and are positioned by retaining rings 32.

Each of the side gears 25 and 27 is a pinion gear 2
3 and supported from the radial outside. Further, a spherical washer 33 is disposed between the pinion gear 23 and the differential case 3, and bears the centrifugal force of the pinion gear 23 and the meshing reaction force received by the pinion gear 23 by meshing with the side gears 25 and 27. .

The boss 29 of the left side gear 25 is rotatably supported by a support 35 of the differential case 3.
The boss 31 of the right side gear 27 is rotatably supported by the boss 12 of the differential case 3 via a right axle. A thrust washer 37 is disposed between the right side gear 27 and the differential case 3, and receives a meshing thrust force of the side gear 27. The spherical washer 33, the pinion shaft 17, the pinion gear 23, and the side gears 25 and 27 are movable on the groove 21 in the axial direction.

Thus, the differential mechanism 39 of the bevel gear type is constituted.

The driving force of the engine for rotating the differential case 3 is distributed from the pinion shaft 17 to the side gears 25 and 27 via the pinion gear 23 and transmitted to the left and right wheels via the respective axles. Further, for example, when a driving resistance difference occurs between wheels during traveling on a rough road, the driving force of the engine is differentially distributed to each wheel side by the rotation of each pinion gear 23.

A multi-plate clutch 43 (friction clutch) is arranged between the top 41 of the left side gear 25 and the differential case 3. On the left side is a hydraulic actuator 45
Is disposed, and further to the left thereof, a radial piston pump 47 is disposed.

As shown in FIGS. 1 and 3, the multiple disc clutch 4
3 comprises a plurality of alternately arranged outer plates 49 and inner plates 51, each outer plate 49 having four projections 53 formed in the axial groove 55 of the differential case 3.
Movably engage with each other, and similarly,
Is movably engaged with the axial groove 57 of the top 41.
A buckling 59 is arranged between the multi-plate clutch 43 and the differential case 3 to bear the pressing force on the multi-plate clutch 43.

As shown in FIG. 1, the hydraulic actuator 4
The fifth piston 61 is disposed between the pump case 63 (cylinder member) of the radial piston pump 47 and the differential case 3 via seal rings 65 and 67 so as to be axially movable. The cylinder 69 of the hydraulic actuator 45 is formed between the piston 61, the pump case 63, and the differential case 3. A thrust washer 71 is disposed between the hub portion 29 of the left side gear 25 and the pump case 63, and receives a meshing thrust force of the side gear 25.

As shown in FIGS. 1 and 4, the radial piston pump 47 is disposed in a space provided in the differential case 3, and includes a pump case 63, cam members 73,
Radial pistons 75, 10 coil springs 77
(Biasing member: forcibly operating means), a check valve 79 on the suction side, a check valve 81 on the discharge side, and the like arranged for each radial piston 75.

The pump case 63 is fixed to the differential case 3 by bolts 83. The cam member 73 is connected so as to rotate integrally with the side gear 25 by a spline portion 85 provided between the cam member 73 and the outer periphery of the boss portion 29 of the left side gear 25, and between the inner peripheral side of the pump case 63 and the differential case 3. Are arranged so as to be relatively rotatable. As shown in FIG. 4, a cam surface 91 having six convex portions 87 and concave portions 89 is provided on the outer periphery of the cam member 73.

Thrust washers 92 are arranged between the cam member 73 and the differential case 3 and the pump case 63, respectively, to prevent abrasion due to sliding.

Each radial piston 75 is disposed in a cylinder 93 formed in the pump case 63 so as to be movable in the radial direction.
The radial piston 75 is arranged on the cam surface 9
1 is pressed.

The strength of the coil spring 77 is adjusted so as to bend under the centrifugal force of the radial piston 75.

As shown in FIGS. 1 and 5, each check valve 79 on the suction side has a suction port 97 formed on the cover 7 of the differential case 3 and communicating with the cylinder 93 via an oil passage 95 of the pump case 63. The suction port 97 is constituted by a valve 99 that opens and closes from the radial piston 75 side. When the suction port 97 is opened and closed by the valve 99, oil flows from the suction port 97 to the cylinder 93 and suction from the cylinder 93 is performed. Return oil to port 97 is shut off.

As shown in FIG. 1 and FIG. 6, each check valve 81 on the discharge side has a discharge port 101 formed in the pump case 63 for communicating the cylinder 93 with the cylinder 69 of the hydraulic actuator 45, and the discharge port 101. And a valve 103 that opens and closes from the hydraulic actuator 45 side.
By opening and closing 1, oil flows from the suction port 101 to the cylinder 69 of the hydraulic actuator 45, and the return oil from the cylinder 69 to the suction port 101 is shut off.

As shown in FIG. 6, the valve 103 is formed by integrating a reed valve 105 (valve piece) for opening and closing each suction port 101 with a ring member 106 (base) to form a petal. To the pump case 63.

An oil pocket 107 is provided on the side of the cover 7.
Are mounted liquid tight. This oil pocket 10
Reference numeral 7 is connected to a fixed system member and is slidable and rotatable with respect to the cover 7, and forms an oil chamber 109 with the cover 7. The suction port 97 of the suction side check valve 79 opens into the oil chamber 109.

The oil pipe 107 is provided in the oil pocket 107.
The oil pipe 111 communicates the oil reservoir 10 of the differential carrier with the oil chamber 109 via an oil strainer and a control valve.

The piston 6 of the hydraulic actuator 45
1 is provided with an orifice 113.

Thus, the differential device 1 is configured.

When differential rotation occurs in the differential gear mechanism 39,
In the radial piston pump 47, the pump case 63 on the differential case 3 side and the cam member 7 on the left side gear 25 side
3 rotate relative to each other, each radial piston 75 moves in the radial direction by the cam surface 91 of the cam member 73, and the radial piston pump 47 operates.

At this time, the radial piston 75 pushed by the projection 87 of the cam surface 91 is pushed into the cylinder 93 against the urging force of the coil spring 77, and the concave 89 of the cam surface 91
Is forcibly pushed back toward the recess 89 by the coil spring 77.

In the cylinder 93 into which the radial piston 75 is pushed, the suction side check valve 79 is closed by the positive pressure of the oil, the discharge side check valve 81 is opened, and the oil is sent to the hydraulic actuator 45.

In the cylinder 93 in which the radial piston 75 has been pushed back, the discharge side check valve 81 is closed by the negative pressure of the oil, the suction side check valve 79 is opened, and the oil reservoir 10 is moved from the oil pipe 111 to the oil chamber. Oil is sucked into the cylinder 93 via the suction port 97, the suction port 97 and the oil passage 95.

No matter which direction the differential gear mechanism 39 rotates differentially, such operations are alternately performed in each cylinder 93, so that the oil is continuously sucked up from the oil reservoir 10 and the hydraulic actuator 45 Sent.

When the oil is sent, the hydraulic actuator 45 presses the multi-plate clutch 43 via the piston 61 to engage it.

The frictional resistance of the multi-plate clutch 43 thus obtained and the pump work of the radial piston pump 47 become a differential limiting force, and the differential of the differential gear mechanism 39 is limited by the differential limiting force. Since the frictional resistance and the pump work increase as the differential rotation speed increases, the differential limiting function is a differential rotation speed sensitive type.

The cylinder 6 of the hydraulic actuator 45
9 is applied with oil pressure, air mixed with the oil and an appropriate amount of oil are discharged from the orifice 113 of the piston 61, and the discharged oil is engaged with the meshing portions of the multi-plate clutch 43 and the gears of the differential gear mechanism 39. The sliding portion, the sliding portion between the pinion gear 23 and the pinion shaft 17 and the spherical washer 33, and the like are lubricated, discharged to the outside through an opening 115 provided in the differential case 3 by centrifugal force, and returned to the oil reservoir 10 of the differential carrier.

Further, the radial piston pump 47 has a small oil leakage and has a radial piston 75 and a cylinder 9.
Since 10 sets of 3 are provided, a sufficient oil discharge amount and a high discharge pressure can be obtained, unlike the conventional example of FIG. And a large differential limiting force can be obtained.

Accordingly, in the vehicle using the differential device 1, the dynamic performance is sufficiently improved by the large differential limiting force. For example, idling of the drive wheels is prevented on a rough road, so that the running performance and the running stability are improved. And greatly improve. Further, a sufficient differential limiting function can be obtained even when the differential rotation speed (△ N) is low.

As described above, the coil spring 77 is adjusted so as to be deflected by the centrifugal force of the radial piston 75. Therefore, when the differential rotation speed is greatly increased, the stroke of the radial piston 75 is reduced and the discharge is reduced. The pressure drops, the frictional resistance of the multi-plate clutch 43 and the pumping work of the radial piston pump 47 are reduced, and the differential lock is prevented. Further, since the radial piston pump 47 is hardly affected by the temperature change of the oil, Even if the temperature drops, a sufficient amount of oil is sucked in and discharged at a high pressure.

Therefore, a large differential limiting force can be obtained even during a period when the oil temperature does not rise sufficiently in winter or the like.

Further, since the radial piston 75 is forcibly returned to the concave portion 89 of the cam surface 91 by the coil spring 77, when a differential rotation occurs, a differential limiting force is instantaneously generated, and a differential limiting force is generated. Is performed, and the running performance and running stability of the vehicle on rough roads and during acceleration are improved.

Further, the coil spring 77 of the forcible operating means is inexpensive, and can be configured at a low cost.

Also, unlike the prior art in which the use of the gear pump makes the check valve mechanism for obtaining the differential limiting force both forward and backward very complicated, the radial piston pump 47 has an oil sump. By merely arranging the check valve 79 on the 10 side (suction side) and arranging the check valve 81 on the hydraulic actuator 45 side (discharge side), a differential limiting force can be obtained both during forward movement and during reverse movement.

As described above, the check valve mechanism (the check valves 79 and 81) has a simple structure, a small number of parts, and a low cost.

In the discharge-side check valve 81,
A number of reed valves 10 based on the ring member 106
5 is used, the number of parts is greatly reduced and the displacement of each reed valve 105 with respect to the suction port 101 is suppressed as compared with the case where each valve piece is formed separately. Valve 8
1 is stabilized, and the differential limiting function is stabilized.

Further, as described above, since a sufficient oil discharge amount and a high discharge pressure can be obtained by using the radial piston pump 47, the gear pump must be large in order to improve the oil discharge amount and the like. Unlike the conventional example, there is no need to increase the size and weight of the differential device 1, and it is not necessary to reduce the accommodation space of the multi-plate clutch 43 in order to avoid an increase in size.
The reduction of the differential limiting force is prevented.

Next, a second embodiment of the present invention will be described with reference to FIGS. This embodiment is described in claims 1, 4, 5,
6, 8, 9 and 11 are provided. FIG. 7 shows a differential device 117 of this embodiment, and FIG.
It is FF sectional drawing of.

In the description of the second embodiment and FIGS. 7 and 8, members having the same functions as those of the first embodiment are given the same reference numerals and are quoted. The differences will be mainly described. Also, each of AA and B in FIG.
-B, DD, and EE are cross-sectional views taken along lines AA and B- in FIG.
B, DD, and EE are the same as the cross section.

The differential device 117 includes a differential mechanism 39, a multi-plate clutch 43, a hydraulic actuator 45, a radial piston pump 119, and a coil spring 121 (an urging member that applies an initial torque and prevents oil from flowing backward).
It is composed of

As shown in FIGS. 7 and 8, the radial piston pump 119 is disposed in the space of the differential case 3, and includes a pump case 63, a cam member 73, ten radial pistons 123, and ten coil springs. 77, a suction-side check valve 79 and a discharge-side check valve 81 arranged for each radial piston 123, and the like.

Each of the radial pistons 123 is disposed in the cylinder 93 of the pump case 63, and each of the coil springs 7
7 is the radial piston 123 and the cam surface 9 of the cam member 73.
1 is pressed.

The radial piston 123 has a small-diameter projecting portion 125 formed at a radially outer end portion. When the radial piston 123 is pushed into the cylinder 93 by the cam surface 91, each projecting portion 125 It protrudes to a position facing the oil passage 95 of the valves 79 and 81 and the discharge port 101.

By providing such a protrusion 125 on the radial piston 123, the oil capacity of each cylinder 93 is reduced.

The coil spring 121 is disposed between the piston 61 of the hydraulic actuator 45 and the side gear 25, and presses the reed valve 105 of the discharge-side check valve 81 via the piston 61.

Thus, the differential device 117 is configured.

In the differential device 117, similarly to the differential device 1, when the differential gear mechanism 39 performs differential rotation, the radial piston pump 119 operates, and the radial piston pump 119 is actuated by the convex portion 87 of the cam surface 91 and the coil spring 77. The oil 123 is reciprocated, oil is sent to the hydraulic actuator 45, and the differential of the differential gear mechanism 39 is limited by the frictional resistance of the multi-plate clutch 43 and the pump work of the radial piston pump 119.

Further, unlike the conventional example, a sufficient oil discharge amount and a high discharge pressure can be obtained by using the radial piston pump 119 having a small oil leakage and a large number of cylinders, and a large differential limiting force can be obtained. Therefore, the dynamic performance of the vehicle can be sufficiently improved, and a sufficient differential limiting function can be obtained even when the differential rotation speed (△ N) is low.

The radial piston pump 119, which is hardly affected by oil temperature changes, draws in a sufficient amount of oil and discharges it at a high pressure even if the oil temperature drops. A large differential limiting force can be obtained even if the force does not rise sufficiently.

In addition to this, the projecting portion 125 provided on the radial piston 123 reduces the oil capacity of the cylinders 93, so that a large discharge pressure can be obtained with a small amount of oil in each cylinder 93, and the frictional resistance of the multi-plate clutch 43. The pump work of the radial piston pump 119 increases accordingly, and the differential limiting force is strengthened.

Further, since the piston 61 of the hydraulic actuator 45 is pressed against the reed valve 105 of the discharge side check valve 81 by the coil spring 121, the reverse flow of oil flowing from the radial piston pump 119 into the cylinder 69 of the hydraulic actuator 45 is prevented. Thus, the differential limiting force is prevented from lowering, and the differential limiting function is stabilized.

The differential device 117 has the same effect as the differential device 1 in addition to the above effects.

The coil spring 121 is connected to the piston 61 of the hydraulic actuator 45 and the reed valve 105.
And may be arranged between them.

The arrangement of the coil spring 121 in this way allows the multiple disc clutch 43 to prevent the piston 61 of the hydraulic actuator 45 from having the effect of preventing the discharge side check valve 81 from flowing backward. And the initial torque is obtained.

With this initial torque, the running performance and running stability of the vehicle on a rough road or during acceleration are improved.

Next, a third embodiment of the present invention will be described with reference to FIGS. This embodiment is defined in claims 1, 4, 7,
It has eight features. FIG. 9 shows a differential device 127 of this embodiment, and FIG. 10 is a sectional view taken along line GG of FIG.

The description of the third embodiment and FIGS. 9 and 10
In the following, members having the same functions as those of the first and second embodiments will be given the same reference numerals and will be quoted, and duplicate explanations of these same members will be omitted, and differences will be mainly described. In addition, each A-
A, BB, DD, and EE cross sections are AA,
It is the same as BB, DD, and EE cross sections.

The differential device 127 includes a differential mechanism 39, a multi-plate clutch 43, a hydraulic actuator 45, a radial piston pump 129, and the like.

As shown in FIGS. 9 and 10, the radial piston pump 129 is arranged in the space of the differential case 3, and includes a pump case 63, a cam member 131, ten radial pistons 133, and each radial piston 133. , A suction-side check valve 79, a discharge-side check valve 81, and the like.

Each radial piston 133 is arranged in the cylinder 93 of the pump case 63.

The cam member 131 is connected to the side gear 25 by a spline portion 85 provided between the cam member 131 and the boss 29, and is rotatably disposed between the inner peripheral side of the pump case 63 and the differential case 3. I have. Cam member 1
Thrust washers 92 are disposed between the pump case 31 and the differential case 3 and the pump case 63, respectively, to prevent abrasion thereof due to sliding.

As shown in FIG. 10, the cam member 131 is formed with a cam groove 135 that opens in the axial direction.

A pin 137 is attached to each radial piston 133.
(Projection) is fixed, and this pin 137 is engaged with the cam groove 135 of the cam member 131. Therefore, when the pump case 63 (cylinder 93) and the cam member 131 rotate differentially, the radial piston 133
Reciprocate along 5.

As described above, the pin 137 and the cam groove 135 serve as forcibly operating means for forcibly moving the radial piston 133.

Thus, the differential device 127 is configured.

In the differential gear 127, similarly to the differential gears 117, 117, the differential gear mechanism 39 is provided.
When the differential rotation occurs in the pump case 63 and the cam member 1
31 rotates relative to each other, and the radial piston pump 129 operates.

At this time, each radial piston 133 is forcibly reciprocated by the engagement between the pin 137 and the cam groove 135, and in the cylinder 93 into which the radial piston 133 is pushed, the suction side check valve 79 is pressed by the positive oil pressure. Is closed, the discharge side check valve 81 is opened, oil is sent to the hydraulic actuator 45, and in the cylinder 93 in which the radial piston 133 is pulled back, the discharge side check valve 81 is closed by the negative pressure of the oil, and the suction side check is performed. The valve 79 is opened, and the oil is sucked up from the oil sump 10.

No matter which direction the differential gear mechanism 39 rotates differentially, oil is sent to the hydraulic actuator 45 in this manner, and the oil is transmitted by the frictional resistance of the multi-plate clutch 43 and the pump work of the radial piston pump 129. The differential of the differential gear mechanism 39 is limited.

Further, since a large differential limiting force can be obtained by using the radial piston pump 129 with little oil leakage and a large number of cylinders, the dynamic performance of the vehicle can be sufficiently improved and the differential rotation can be improved. Number (△ N)
, A sufficient differential limiting function can be obtained.

The radial piston pump 129, which is hardly affected by oil temperature changes, draws in a sufficient amount of oil and discharges it at a high pressure even if the oil temperature drops. A large differential limiting force can be obtained even if the force does not rise sufficiently.

Further, the pin 137 of the radial piston 133 is engaged with the cam groove 135 of the cam member 131 to constitute the forced operation means. When differential rotation occurs, a differential limiting force is instantaneously generated. Differential limiting is performed, and the running performance and running stability of the vehicle are improved on rough roads and during acceleration.

The differential device 127 has the same effect as the differential device 1 in addition to the above.

In the present invention, the differential gear mechanism is not limited to the bevel gear type. For example, a torque-sensitive differential limiting mechanism utilizing the frictional resistance between each gear and the frictional resistance between each gear and the differential case is used. A helical gear type differential gear mechanism that obtains a function may be used.

By using such a differential gear mechanism, a differential device having a speed-sensitive differential limiting function using a friction clutch and an oil pump in addition to the torque-sensitive differential limiting function can be obtained.

Further, the clutch for limiting the differential is not limited to the multi-plate clutch, but may be another type of friction clutch such as a cone clutch.

Further, the differential device of the present invention
Front differential (differential device that distributes engine driving power to left and right front wheels) and rear differential (differential device that distributes engine driving force to left and right rear wheels)
And a center differential (a differential device that distributes the driving force of the engine to the front wheels and the rear wheels).

[0131]

According to the differential device of the first aspect,
The frictional resistance of the friction clutch and the pump work of the radial piston pump provide a speed-sensitive differential limiting function.

Further, unlike the conventional example using a gear pump having a large amount of oil leakage, a sufficient oil discharge amount can be obtained by using a radial piston pump having a large number of sets of radial pistons and cylinders, in addition to having a small oil leakage. And a high discharge pressure can be obtained, and a large differential limiting force can be obtained, so that the dynamic performance of the vehicle can be sufficiently improved, the differential limiting function is stabilized, and the differential rotation speed (△ N) is reduced. Even at a low level, a sufficient differential limiting function can be obtained.

Further, since the radial piston pump is hardly affected by a change in oil temperature, a sufficient oil discharge amount and a high discharge pressure can be obtained even if the oil temperature drops, and the oil temperature does not rise sufficiently in winter and the like. A large differential limiting force can be obtained between them.

Accordingly, it is not necessary to increase the size of the pump in order to increase the amount of oil and the discharge pressure. Therefore, unlike the conventional example, the differential device is not increased in size and weight, and the size of the differential device is reduced. Since it is not necessary to reduce the space for accommodating the friction clutch, a decrease in clutch capacity and differential limiting force is prevented.

Also, unlike the gear pump, the radial piston pump does not change the suction direction and the discharge direction even if the rotation direction changes. Therefore, only one suction side check valve and one discharge side check valve are arranged for each cylinder. Therefore, the differential limiting force can be obtained both when the vehicle is moving forward and when the vehicle is moving backward, and the valve mechanism has such a simple structure, the number of parts is reduced, and the cost is reduced.

In the clutch device according to the second aspect, power is transmitted by the frictional resistance of the friction clutch and the pump work of the radial piston pump.

Also, by using a radial piston pump which has a small number of oil leaks, has a large number of cylinder sets, and can obtain a high discharge pressure, it is possible to transmit a large power, and when the relative rotational speed of input and output is low. However, a sufficient power transmission function can be obtained.

Further, since a high discharge pressure can be obtained by the radial piston pump even when the temperature of the oil drops, a large power can be transmitted even in a winter season even when the oil temperature does not rise sufficiently.

The use of a radial piston pump having a high discharge pressure makes it possible to make the clutch device compact and lightweight, and it is not necessary to reduce the space for accommodating the friction clutch in order to reduce the size and weight of the device. Is prevented from decreasing.

Further, by using a radial piston pump, power can be transmitted in any rotational direction by a valve mechanism having a small number of parts and a simple structure.

According to the third aspect of the invention, the same effects as those of the second aspect are obtained.

According to the fourth aspect of the present invention, the same effect as that of the first, second, or third aspect is obtained, and the provision of the forced operating means for forcibly moving the radial piston along the cam is provided. When the cylinder and the cam member of the radial piston pump rotate differentially or relatively, a differential limiting force is instantaneously generated in the differential device of claim 1, and power transmission is instantaneously performed in the clutch device of claim 2 or 3. Will be

According to the fifth aspect of the present invention, the same effect as that of the fourth aspect is obtained, and the apparatus can be constructed at low cost by using the urging member for the forcibly operating means. 6 becomes possible.

According to the sixth aspect of the invention, the same effect as that of the fifth aspect is obtained, and the biasing member is bent by the centrifugal force of the radial piston, so that the stroke of the radial piston is reduced and the discharge pressure is reduced. Therefore, the differential device can prevent the differential lock when the differential rotation speed is significantly increased, and the clutch device can prevent the friction clutch and the driven machine from being damaged when excessive torque is input. Can be.

The invention according to claim 7 has the same effect as the structure according to claim 4.

According to the eighth aspect of the present invention, the same effects as in any one of the first to seventh aspects are obtained, and a large number of valve pieces constituting the check valve are integrally formed. The number of parts is greatly reduced as compared with the case where they are separate, and the displacement of each valve piece with respect to the oil port is suppressed and the operation of the check valve is stabilized, so the differential limiting function of the differential device and the clutch device The power transmission function is stabilized.

According to the ninth aspect of the present invention, the same effect as any one of the first to eighth aspects is obtained, and the discharge side check valve is pressed by the urging member to prevent the oil from flowing backward. Therefore, the differential limiting force of the differential device and the coupling force of the clutch device are prevented from lowering, and these operations are stabilized.

According to the tenth aspect of the present invention, the same effect as any of the first to ninth aspects can be obtained, and the discharge side check valve is pressed by the urging member to prevent the oil from flowing backward. At the same time, the friction clutch is pressed to obtain an initial torque.

With this initial torque, the running stability of the vehicle is improved during acceleration or on a rough road in a differential device, and an extremely small torque can be transmitted in a clutch device.

According to the eleventh aspect of the present invention, the same effects as those of any of the first to tenth aspects are obtained, and
The protruding portion provided on the radial piston reduces the oil capacity of the cylinder, and a large discharge pressure can be obtained in each cylinder with a small amount of oil. Therefore, the differential limiting force of the differential device and the clutch capacity of the clutch device are enhanced accordingly.

[Brief description of the drawings]

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

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a sectional view taken along the line CC of FIG. 1;

FIG. 5 is a sectional view taken along line DD of FIG. 1;

FIG. 6 is a sectional view taken along the line EE of FIG. 1;

FIG. 7 is a sectional view showing a second embodiment of the present invention.

FIG. 8 is a sectional view taken along line FF of FIG. 7;

FIG. 9 is a sectional view showing a third embodiment of the present invention.

FIG. 10 is a sectional view taken along line GG of FIG. 9;

FIG. 11 is a sectional view of a conventional example.

[Explanation of symbols]

1, 117, 127 Differential device 3 Differential case 10 Oil reservoir 25, 27 Output side gear 39 Differential gear mechanism 43 Multi-plate clutch (friction clutch) 45 Hydraulic actuator 47, 119, 129 Radial piston pump 61 Piston of hydraulic actuator 63 Radial piston Pump pump case (cylinder member) 69 Hydraulic actuator cylinder 73, 131 Cam member 75, 123, 133 Radial piston 77 Coil spring (biasing member: radial piston forced actuation means) 79 Suction side check valve 81 Discharge side check valve 91 Cam Cam surface of member 73 97 Suction port 101 Discharge port 103 Valve 105 Reed valve (valve piece) 106 Ring member (base) 121 Coil spring (prevents oil from flowing backward) Convex portions of the urging member) 125 cam groove (forced activation means projecting portion 135 cam member 131 of the radial piston 123) 137-pin (radial piston 133 to provide an initial torque: forced activation means)

Claims (11)

[Claims] 1. A differential case that is rotationally driven by a driving force of an engine, a differential mechanism that outputs rotation of the differential case through a pair of output side gears, a friction clutch that limits a differential of the differential mechanism, and a differential case side. A radial piston movably engaged with a cylinder member fixed to the differential case, and a cam member that rotates differentially with respect to the differential case and pushes the radial piston into the cylinder from the radial inside by a cam, and is provided on the differential case. A radial piston pump disposed in a closed space, a piston and a cylinder, a hydraulic actuator receiving the hydraulic pressure of the radial piston pump in the cylinder, pressing the friction clutch through the piston and engaging the same, and radially transmitting the oil from the suction port. A check valve on the suction side for suction into the cylinder of the piston pump, and a radial A differential device comprising: a discharge-side check valve for discharging discharge oil of a piston pump from a discharge port to an actuator side. 2. A clutch housing which can be relatively rotated and a cam member disposed inside the clutch housing, a friction clutch for connecting the clutch housing and the clutch housing, and a relative rotation between the clutch housing and the cam member which is disposed in a space provided in the clutch housing. And a hydraulic actuator comprising a piston and a cylinder, receiving a hydraulic pressure of the radial piston pump in the cylinder, and pressing and engaging the friction clutch via the piston. apparatus. 3. A radial piston pump radially inwardly engages with a cylinder member fixed to a clutch housing by a cam when a relative rotation occurs between the radial piston and a clutch housing. A cam member for pushing oil into the cylinder, a suction check valve for sucking oil into the cylinder of the radial piston pump, and a discharge check valve for discharging oil from the cylinder of the radial piston pump. A clutch device as described. 4. The apparatus according to claim 1, further comprising forcible operating means for moving the radial piston along the cam in accordance with the differential rotation or relative rotation of the cylinder and the cam member of the radial piston pump. A clutch device according to claim 2 or 3, wherein the clutch device is a differential device. 5. The cam is a cam surface formed on the outer periphery of the cam member, and the forcible actuating means is an urging member disposed on a cylinder of the radial piston pump and pressing the radial piston against the cam surface from the outside in the radial direction. The differential device or the clutch device according to claim 4, wherein the differential device or the clutch device is provided. 6. The strength of the urging member is adjusted such that the centrifugal force of the radial piston causes the urging member to bend, narrow the stroke of the cylinder, and reduce the discharge pressure of the radial piston pump. The differential device or the clutch device according to claim 5, wherein 7. A cam groove in which a cam is opened in an axial direction of a cam member. A convex portion on a radial piston side is engaged with the cam groove, and these convex portions and the cam groove are formed between the cylinder and the cam member. The differential device or the clutch device according to claim 4, wherein a forced operation means for moving the radial piston along the cam groove with the differential rotation is formed. 8. One or both of the suction-side check valve and the discharge-side check valve includes a number of oil ports arranged in a circumferential direction, and a valve piece for closing the oil ports.
The differential device or the clutch device according to any one of claims 1 to 7, wherein each valve piece is formed integrally with the ring member as a base. 9. The device according to claim 1, further comprising an urging member that presses the discharge-side check valve via a piston of the hydraulic actuator to prevent reverse flow of the oil. Differential device or clutch device. 10. A biasing device which is disposed between a piston of a hydraulic actuator and a discharge side check valve, presses the discharge side check valve to prevent reverse flow of oil, and applies an initial torque to a friction clutch via the piston. 10. A device according to claim 1, wherein a member is provided.
The differential device or the clutch device according to any one of the above. 11. The radial piston according to claim 1, wherein a projecting portion is provided on the radial piston, and the projecting portion is arranged so as to project toward the suction port and the discharge port in the compression step. Differential device or clutch device.