JPH10339367A - Hydraulic clutch and power transmitting device provided with this hydraulic clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic clutch whereby sufficient torque can be transmitted by a simple structure and a power transmitting device provided with this hydraulic clutch. SOLUTION: This device has a differential case 3 received in a carrier case provided with an oil reservoir inputted with rotational drive force of an engine, bevel gear type differential mechanism 7 distributing and outputting drive force to a side gear 13, 15 arranged to be opposed in the differential case 3, and a piston pump 41 of radial type supplying pressure oil to a hydraulic clutch 25 to connect it according to differential action of both the side gear 13, 15 with differential action limited. A suction/delivery port of the piston pump is arranged to be displaced by a prescribed amount, so as to eliminate necessity for an exclusive use suction side check valve.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic clutch and a power transmission having the same.

[0002]

2. Description of the Related Art As a conventional power transmission device using a hydraulic clutch, for example, the one shown in FIG.

[0003] The power transmission device 201 is provided with a hollow cylindrical housing 203 on the outside, and a cam 203a is formed on an inner surface of a wall on one end side of the housing 203. A rotor 205 is rotatably housed in a hollow portion of the housing 203, and a plurality of plungers 207 in the rotor 205 are pressed by a spring 209 against a cam 203a and are in contact therewith.

[0004] Outer housing 203 and inner rotor 2
When a rotation difference is generated between the plunger 505 and the cam 203a, the plunger 207 abutting on the convex portion of the cam 203a reciprocates according to the shape of the cam 203a, and moves to the left in FIG. Then, the oil in the plunger chamber 215 is pushed out to the high-pressure chamber 213 at the shaft center, and further guided to the low-pressure chamber 219 through the orifice 217. At this time, orifice 2
The hydraulic pressure of the plunger chamber 215 increases due to the resistance of the throttling of the 17 parts. Since the hydraulic pressure generated in the plunger chamber 215 resists a rotation difference between the housing 203 and the rotor 205, power is transmitted between the two at this time.

At this time, the plunger 207 which comes into contact with the valley of the cam 203a is pushed by the spring 209 and moves rightward in FIG.
19 through a flow path 221 communicating with the plunger chamber 215.
Inhale the oil inside.

When the rotation difference between the housing 203 and the rotor 205 reaches a predetermined value and the oil pressure in the plunger chamber 215 reaches a predetermined value, the orifice 217 is closed, the power transmission 201 is locked, and the two are integrated. Rotate.

[0007]

However, in the power transmission device 201, the orifice 217 is used to sufficiently reduce the transmission torque and pulsation due to insufficient suction by keeping the oil suction into the plunger chamber 215 sufficiently. Since the plate member 223 and the accumulator 225 are provided at the outlet of the above, there is a problem that the structure becomes complicated and the cost increases.

Accordingly, an object of the present invention is to provide a hydraulic clutch capable of transmitting a sufficient torque with a simple structure and a power transmission device provided with the hydraulic clutch.

[0009]

According to a first aspect of the present invention, a driving member and a driven member are rotatably engaged with each other in a rotational direction, and are alternately arranged in an axial direction. A friction plate, a hydraulic actuator comprising a cylinder and a piston for pressing the two friction plates, and a hydraulic pressure supplied to the hydraulic actuator with the relative rotation of the two members to press the two friction plates to connect the two members. A piston pump is provided, and the suction port and the discharge port of the piston pump are displaced from each other by a predetermined amount, so that a dedicated suction port side check valve is not provided.

Therefore, since the suction port is closed by the piston at the time of pressure increase due to the displacement between the suction port and the discharge port of the piston pump, no discharge pressure is applied.
It is not necessary to provide a dedicated check valve for each suction port, so that the structure of the hydraulic clutch is simplified and compact, which is advantageous in cost.

According to a second aspect of the present invention, there is provided the hydraulic clutch according to the first aspect, wherein the piston pump includes a hollow portion provided on a rear side hollow portion of the piston for accommodating a spring member for biasing the piston. And a member for reducing the volume of the space.

Therefore, the same operation and effect as those of the first aspect of the invention can be obtained, and the volume of the pump chamber on the back side of the piston can be set to an appropriate size. , And sufficient hydraulic clutch engagement force can be obtained.

According to a third aspect of the present invention, there is provided the hydraulic clutch according to the second aspect, wherein the piston pump is a radial type piston pump.

Therefore, the same functions and effects as those of the first and second aspects can be obtained by the radial type piston pump.

According to a fourth aspect of the present invention, there is provided the hydraulic clutch according to the second aspect, wherein the piston pump is an axial type piston pump.

Therefore, the same functions and effects as those of the first and second aspects can be obtained by the axial type piston pump.

According to a fifth aspect of the present invention, there is provided a power transmission device provided with the hydraulic clutch according to the third or fourth aspect, wherein the differential case is accommodated in a carrier case having an oil sump and receives the rotational driving force of the engine. And a differential mechanism for distributing and outputting the driving force to an output-side member facing the inside of the differential case, wherein the hydraulic clutch is provided between the differential case and one of the output members and the differential mechanism is provided. It is characterized in that the differential of the mechanism is limited.

Therefore, the power transmission device can obtain the same operation and effect as those of the first and second aspects by the radial type or axial type piston pump, and also can obtain a sufficient differential limiting force.

In particular, when a radial piston pump is used, the size in the axial direction is reduced, which is advantageous in cost.

According to a sixth aspect of the present invention, there is provided a power transmission device provided with the hydraulic clutch according to the third or fourth aspect, wherein one of the driving side member and the driven side member is coaxially arranged in the other hollow portion. Wherein the hydraulic clutch and the oil tank of the piston pump are provided between the two members.

Therefore, the power transmission device can obtain the same operation and effect as those of the first and second aspects by the radial type or the axial type piston pump, and the internal structure of the oil tank simplifies the structure and provides a sufficient differential. You get the limiting power.

In particular, when an axial piston pump is used, the radial dimension is reduced, which is advantageous in cost.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of the differential device according to the present embodiment. FIG. 2 is a view as viewed in the direction of the arrow A in FIG. 1, and FIG.

Differential device (power transmission device)
The first differential case 3 includes a case main body 3a and a cover 3b connected by bolts 5. The differential case 3 is rotatably supported by a carrier case (not shown) by left and right boss portions 3c and 3d. Further, a ring gear (not shown) is fixed to the differential case 3, and a driving force from the engine is input to the differential case 3 via the ring gear. An oil reservoir is provided in the carrier case, and the differential device 1 is lubricated with an oil bath.

The differential mechanism 7 accommodated in the differential case 3 is a bevel gear type differential mechanism, and is configured as follows.

That is, the pinion shaft 9 is locked in the rotating direction in the concave groove 3e provided in the inner wall of the cylindrical portion of the differential case 3 in the axial direction, and is supported movably in the axial direction. A pinion gear 11 is rotatably supported on the pinion shaft 9, and the pinion gear 11 meshes with left and right output side gears (output side members) 13, 15 coaxially opposed to the differential case 3.

The side gears 13 and 15 are formed by integrating the gear portions 13a and 15a and the shaft portions 13b and 15b, respectively. Thrust washers 17, 19 are arranged on the back surfaces of the side gears 13, 15. Also, the shaft portions 13b, 1
Left and right output shafts (not shown) are spline-connected to the inner periphery of 5b, and are retained by retaining rings 21. An oil groove 23 for lubrication is provided on the inner periphery of the boss portions 3c and 3d of the differential case 3.

The hydraulic clutch 25 is a differential limiting mechanism for limiting the differential of the differential mechanism 7, and is configured as follows.

That is, a clutch plate (friction plate) is provided between the inner wall of the differential case 3 and the outer periphery of the left side gear 13.
27 are arranged. Differential case 3 and side gear 13
Either of them becomes a drive side member or a driven side member according to the differential condition of the differential mechanism 7. The clutch plate 27 is composed of a plurality of outer plates 31 and inner disks 33 alternately arranged in the axial direction. The outer plates 31 are locked to the differential case 3 and the inner disks 33 are locked to the side gears 13 in the rotational direction, respectively. Both are movable in the axial direction.

A clutch piston 35 and a clutch cylinder 39 which constitute a hydraulic actuator are disposed adjacent to the clutch plate 27. Clutch cylinder 3
9 is formed by a pump case 37 and a clutch piston 35. On the other hand, on a wall of the pump case 37 on the clutch cylinder 39 side, a plurality of discharge ports 43 (10 in this embodiment) of a radial type piston pump 41 described later are provided.
) And an eight-handed reed valve 45 (see FIG. 2) made of a thin plate closing each discharge port 43. The reed valve 45 plays the role of a check valve. The pump case 37 is fixed to the differential case 3 together with the reed valve 45 by bolts 47, and a pump chamber 49 is formed on the outer peripheral portion between the two. Thus, the pump chamber 49 rotates integrally with the differential case 3.

On the other hand, a cam member 51 is spline-fitted on the side gear 13 at the center of the piston pump 41,
The cam member 51 rotates integrally with the side gear 13. Thrust washers 53 are arranged on both side surfaces of the cam member 51. As shown in FIG. 3, a cam 51a having a circumferential waveform is formed on the outer periphery of the cam member 51.

As shown in FIG. 3, a radial piston 40 (in this embodiment, 1) is slidably accommodated in a radial cylinder 37a radially provided in a pump case 37.
0) are urged toward the center by the spring 42 against the centrifugal force from the pump chamber 49 side (radially outer side) on the rear surface thereof and abut against the cam 51a. The biasing force of the spring 42 is set to a predetermined value. A rod 55 with a head as a member for reducing the volume of space is inserted into a hollow portion on the rear side of the radial piston 40, and the rod 55 moves with the radial piston 40 by the head portion being pushed by the spring 42.

A suction port 57 is provided on the outer (left end) wall of the pump case 37. The radial position of the suction port 57 is set to be smaller by a predetermined amount than the position of the discharge port 43. The differential case 3 corresponding to the suction port 57
A channel 59 is provided in the wall of the carrier case, and the channel 59 is connected to a suction channel extending from an oil reservoir of a carrier case (not shown). A check valve is not provided in the suction port 57. Thus, the hydraulic clutch 25
A radial type piston pump 41 for operating the pump is constructed.

Next, the operation of the hydraulic clutch 25 and the differential device 1 will be described.

The driving torque from the engine input to the differential case 3 via the ring gear is distributed to the left and right output shafts via the differential mechanism 7. When the drive resistances of both side gears 13 and 15 are equal, both side gears 13 and 15 rotate at a constant speed.

At this time, the differential case 3 and the side gear 13
The radial piston 40 abutting on the cam 51a reciprocates in the radial cylinder 37a due to the rotation difference generated therebetween, and the piston pump 41 operates.

That is, the radial piston 40 is
When abutting against the valley 1a (during the suction stroke), the discharge port 43 is closed by the reed valve 45 as a check valve, so that the pump chamber 49 has a negative pressure, and oil flows from the oil reservoir of the carrier case. The air is sucked into the pump chamber 49 from the suction port 57 opened by the radial piston 40 through the flow path 59 and the suction port 57.

Then, the radial piston 40 has the cam 51
Since the suction port 57 is closed by the radial piston 40 when it is in contact with the peak of a (in the suction stroke),
The pressurized oil in the pump chamber 49 pushes and opens the reed valve 45 from the discharge port 43 to be discharged to the clutch cylinder 39 and presses the clutch piston 35, thereby engaging the hydraulic clutch 25.

At this time, since the volume of the pump chamber 49 is reduced by the rod 55 in the radial piston 40 and is kept small, the discharge pressure of the piston pump 41 easily rises sufficiently. Further, the discharge amount of the piston pump 41 is proportional to the magnitude of the rotation difference between the differential case 3 and the side gear 13. Therefore, the engagement force of the hydraulic clutch 25 changes according to the rotation difference. And, this hydraulic clutch 25
The resistance between the left and right side gears 13 and 15 is limited, and the driving torque of the low-speed side output shaft increases by the amount of the fastening torque. The drive torque of the high-speed output shaft is reduced by the minute.

Thus, according to the present embodiment, the piston pump 41 shifts the radial position between the suction port 57 and the discharge port 43 so that when the oil pressure in the hydraulic chamber 49 increases, the suction port 57 is closed. Therefore, the check valve on the suction port side can be omitted, and the structure can be simplified. This is advantageous in cost.

Further, since the rod 55 with the head is inserted into the radial piston 40, the volume of the pump chamber 49 (the rear surface of the radial piston 40) is reduced, so that the hydraulic pressure of the pump chamber 49 increases without fail, and The hydraulic clutch 25 is provided with a sufficient engagement force.

That is, by using the hydraulic clutch 25 having the radial type piston pump 41 in the differential device 1, a sufficient differential limiting force can be obtained and the radial type piston pump 41 has a compact axial dimension. Becomes

The radial type piston pump 4
It is also possible to use an axial type piston pump instead of 1, and in this case, a sufficient differential limiting force can be obtained.

[Second Embodiment] A second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a sectional view of the coupling of the present embodiment. A duplicate description of the configuration that is apparent from FIG. 4 to be similar to the hydraulic clutch of the first embodiment will be omitted.

As shown in FIG. 4, a coupling (power transmission device) 101 includes an output shaft (driven side member) coaxially surrounding the input shaft 103 via a hollow input shaft (drive side member) 103 and a hydraulic clutch 105. ) 107. A power transmission shaft (not shown) is spline-connected to the inner periphery of the input shaft 103. A driven shaft (not shown) is connected to the right end of the output shaft 107 by a bolt 109.

A stopper plate 111 is oil-tightly screwed to the left end of the output shaft 107 and is positioned by retaining rings 113 and 115. A seal 117 is arranged between the inner periphery of the stopper plate 111 and the outer periphery of the input shaft 103. A hydraulic clutch 105 is disposed between the input shaft 103 and the output shaft 107 adjacent to the inside (right side) of the stopper plate 111.

The hydraulic clutch 105 connects the two shafts 103 and 107 during the differential operation between the input shaft 103 and the output shaft 107, and has the following configuration.

That is, the clutch plate (friction plate) 1
21 is disposed between the input shaft 103 and the output shaft 107;
A plurality of inner disks 123 locked on the input shaft 103 in the rotation direction and a plurality of outer plates 125 locked on the output shaft 107 in the rotation direction are alternately arranged in the axial direction. It is movable in the axial direction.

Further, a clutch piston 127 for pressing the clutch plate 121 is disposed in the concave portion 103b of the large-diameter portion 103a of the input shaft 103, and its inner and outer circumferences are movable via seals 129 and 131.
A clutch cylinder 133 is formed between the recess 103b and the clutch piston 127.
7 constitutes a hydraulic actuator. The clutch piston 127 is provided with an orifice 127a,
The orifice 127a adjusts the hydraulic pressure in the clutch cylinder 133.

The clutch cylinder 133 (recess 10
A plurality of discharge ports 143 of an axial type piston pump 141, which will be described later, are opened on the wall surface 3b), and the eight-handed reed valve 1 made of a thin plate closing the discharge ports 143 is formed.
45 are bolted. This reed valve 145
Serves as a check valve.

As shown in FIG. 4, a large diameter portion 103a of the input shaft 103 is provided with a plurality of axial cylinders 103 in the circumferential direction.
c are provided, and extend in the axial direction to accommodate the axial pistons 147 so that they can enter and exit. The discharge port 143 is provided on the rear side of the axial piston 147 of each axial cylinder 103c.
A suction port 161 communicating with each of the axial cylinders 103c is provided on the outer circumference of 03a. The suction port 161 is positioned at a predetermined position with respect to the stroke of the axial piston 147. As a result, the suction port 161 is closed by the axial piston 147 when the pressure in the axial cylinder 103c increases, so that a dedicated check valve is not required and provided on the suction port 161 side. Thus, the axial type piston pump 14
1 is configured.

On the other hand, a cam member 151 is screwed into and fixed to the inner periphery of the right end of the output shaft 107, and is inserted by seals 153 and 155, and the space between the output shafts 103 and 107 is made oil-tight. A circumferential wavy cam 151a is formed on the surface of the cam member 151 facing the axial piston 147, and the distal end of the axial piston 147 is pressed by a spring 157 to abut the cam 151a.

The space surrounded by the input and output shafts 103 and 107, the stopper plate 111, and the cam member 151 is used as an oil reservoir (oil tank) 159.

Next, the operation of the hydraulic clutch 105 will be described together with the operation of the coupling 101.

When the coupling 101 operates, the input shaft 1
03 and the output shaft 107, the cam 15
The piston pump 141 operates when the axial piston 147 abutting on 1a reciprocates in the axial cylinder 103c. That is, when the axial piston 147 contacts the valley of the cam 151a, the oil in the oil reservoir 159 is sucked through the suction port 161.
Next, when the axial piston 147 abuts on the ridge of the cam 151a, the suction port 161 becomes
7, the axial cylinder 103c
The pressure in the inside increases, and the oil is pushed into the reed valve 147 to be opened and supplied from the discharge port 143 into the clutch cylinder 133.

The clutch piston 1 is driven by the supplied hydraulic pressure.
27 presses the clutch plate 121 to fasten the hydraulic clutch 105. The discharge amount of the piston pump 141 is proportional to the magnitude of the rotation difference between the input and output shafts 103 and 107. Therefore, the engagement force of the hydraulic clutch 105 changes according to the rotation difference. The hydraulic clutch 10
Since the fastening force of No. 5 resists the differential (rotational difference) between the two shafts 103 and 107, the differential between the two shafts 103 and 107 is limited.

When both shafts 103 and 107 rotate at the same rotational speed (there is no differential), the piston pump 141 does not operate, so that the hydraulic clutch 105 is released and power is not transmitted.

Thus, according to the present embodiment, the axial-type piston pump 141 allows the two shafts 103,
At the time of differential operation of 107, a sufficient fastening force of the hydraulic clutch 105 is obtained, and the coupling 101 is engaged, and the output shafts 103 and 10 are engaged.
A sufficient differential limiting force between 7 is obtained.

The oil reservoir 159 is connected to the coupling 1
01, the structure is simplified, and the use of the axial type piston pump 141 makes the coupling 101 radially compact.

It is also possible to use a radial type piston pump instead of the axial type piston pump 141, and in this case, a sufficient differential limiting force can be obtained.

[0061]

As is apparent from the above description, according to the first aspect of the present invention, the suction port is closed by the piston when the pressure is increased due to the displacement between the suction port and the discharge port of the piston pump. Because there is no discharge pressure,
It is not necessary to provide a dedicated check valve for each suction port, so that the structure of the hydraulic clutch is simplified and compact, which is advantageous in cost.

According to the invention described in claim 2, according to claim 1
In addition to obtaining the same effect as the invention of the above, the volume of the pump chamber on the back side of the piston can be set to an appropriate size,
As a result, the piston pump can generate a sufficient discharge pressure, so that a sufficient hydraulic clutch engagement force can be obtained.

According to the third aspect of the invention, the same effects as those of the first and second aspects can be obtained by the radial type piston pump.

According to the fourth aspect of the invention, the same effects as those of the first and second aspects can be obtained by the axial type piston pump.

According to the fifth aspect of the present invention, the power transmission device can obtain the same effects as those of the first and second aspects by a radial type or axial type piston pump, and can obtain a sufficient differential limiting force. Can be

In particular, when a radial piston pump is used, the size in the axial direction is reduced, which is advantageous in cost.

According to the sixth aspect of the present invention, the power transmission device can obtain the same effects as those of the first and second aspects by the radial type or the axial type piston pump, and has a simple structure due to the internal structure of the oil tank. And a sufficient differential limiting force can be obtained.

In particular, when an axial piston pump is used, the size in the radial direction is reduced, which is advantageous in cost.

[Brief description of the drawings]

FIG. 1 is a sectional view of a first embodiment.

FIG. 2 is a view on arrow A of FIG. 1 showing the reed valve of the first embodiment.

FIG. 3 is a view on arrow B of FIG. 1 showing the radial piston pump of the first embodiment.

FIG. 4 is a sectional view of a second embodiment.

FIG. 5 is a sectional view of a conventional example.

[Explanation of symbols]

3 Differential case 7 Differential mechanism 9 Pinion shaft 11 Pinion gear 13, 15 Side gear (output side member) 25, 105 Hydraulic clutch 27, 121 Clutch plate (friction plate) 35, 127 Clutch piston (hydraulic actuator) 37 Pump case 37a Radial cylinder 39 , 133 Clutch cylinder (hydraulic actuator) 40 Radial piston 41 Radial type piston pump 42,157 Spring 43,143 Discharge port 45,145 Reed valve 49 Pump chamber 51,151 Cam member 51a, 151a Cam 55 Rod (reduced space volume) 57,161 Suction port 103 Input shaft (drive side member) 103c Axial cylinder 107 Output shaft (driven side member) 141 Axial type piston pump 147 a Sialic piston 159 oil reservoir (oil tank)

Claims (6)

[Claims] 1. A friction plate which is locked to a driving member and a driven member in a rotation direction and is alternately arranged in an axial direction with each other; a hydraulic actuator comprising a cylinder and a piston for pressing the friction plates; A piston pump that supplies hydraulic pressure to the hydraulic actuator with the relative rotation of the two members and presses the two friction plates to connect the two members together, wherein a suction port and a discharge port of the piston pump are shifted by a predetermined amount. A hydraulic clutch characterized in that it is not provided with a dedicated suction port side check valve by being disposed. 2. The hydraulic clutch according to claim 1, wherein the piston pump has a hollow portion on the back side of the piston that accommodates a spring member that biases the piston, and reduces a space volume of the hollow portion. A hydraulic clutch comprising: 3. The hydraulic clutch according to claim 2, wherein the piston pump is a radial type piston pump. 4. The hydraulic clutch according to claim 2, wherein the piston pump is an axial type piston pump. 5. A power transmission device comprising the hydraulic clutch according to claim 3 or 4, wherein the differential case is accommodated in a carrier case having an oil reservoir and receives a rotational driving force of an engine, and is opposed to the differential case. A differential mechanism for distributing and outputting the driving force to the output member disposed, and the hydraulic clutch is provided between the differential case and one of the output members to limit the differential of the differential mechanism. A power transmission device characterized by the above-mentioned. 6. A power transmission device comprising the hydraulic clutch according to claim 3 or 4, wherein one of the power transmission device and the driven side member is coaxially disposed in the other hollow portion. A power transmission device comprising the hydraulic clutch and an oil tank of the piston pump between members.