JPH05141452A - Oil pressure pump for power transmitting device - Google Patents

Abstract

PURPOSE:To enable a whole device to be designed compact by providing a valve seat directly in an operating oil passage in a side plate, forming an annular groove at a rotor-side opening of each of the operating oil passages to connect valve seats between them, and by preventing a ball valve from coming- off by means of a snap ring fitted into the annular groove. CONSTITUTION:A driving force transmitting device for a four-wheel drive vehicle is equipped with a vane pump 3 which is located between a housing 13 and a rotating cylinder shaft 12 and transmits a torque corresponding to a difference between the rotating speed of a casing 30 rotating interlocked with a front-wheel side driving shaft, and the rotating speed of a rotor 31 which rotates interlocked with a rear-wheel side driving shaft. The vane pump 3 is furnished with a check valve A in an operating oil passage 38a formed in a side plate 9. The check valve A is composed of plural valve seats A1 formed directly on the same circumference as that of the side plate 9, a ball piece A2, and a snap ring 3A which prevents the ball piece A2 from interfering with the side surface of the rotor 31. The snap ring A3 is fitted into an annular groove A4 by pressing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic pump for a power transmission device, and more particularly to a four-wheel drive vehicle for transmitting a driving force by interposing a pair of drive shafts for the four-wheel drive vehicle. The present invention relates to a hydraulic pump for a power transmission device which is optimal for a driving force transmission device.

[0002]

2. Description of the Related Art Generally, a hydraulic pump of this type mainly transmits power for connecting front and rear wheels of a four-wheel vehicle in a state where a predetermined differential rotation is allowed in order to prevent deterioration of turning performance of the four-wheel vehicle. It is adopted in the device. As shown in FIG. 4, the structure includes a rotor 100 that rotates in conjunction with one of a driving member and a driven member, and a casing 101 that rotates in conjunction with the other while housing the rotor 100. The casing 101 includes a side plate 102 that is in sliding contact with the side surface of the rotor 100, and an annular cam ring 103 that is arranged on the outer peripheral side of the rotor 100.
And in the space surrounded by the side plate 102 of the casing 101, the cam ring 103, and the rotor 100,
A pump chamber 104 is formed, and this pump chamber 104
In addition, a hydraulic pressure is generated according to the difference in rotational speed between the rotor 100 and the casing 101, and torque is transmitted between the two via the hydraulic pressure.

Further, the pump chamber 1 is supplied with oil pressure corresponding to the rotational speed difference.
04, the side plate 102 of the casing 101 is formed with a hydraulic oil passage 110 in which the check valve A10 is interposed. One end of the hydraulic oil passage 110 communicates with the pump chamber 104 and the other end of the side plate 1
02 extends substantially in the radial direction and opens on the sliding contact surface with the rotor 100, and the check valve A10 is arranged in a state of facing the rotor 100.

In order to arrange the check valve A in the hydraulic oil passage 110, a valve unit accommodating portion 110a is formed on the other end side of the hydraulic oil passage 110, and in the valve unit accommodating portion 110a, Check valve A10 consisting of unit members
Is housed. The check valve A10 includes a metal case A101, a ball valve A102 housed in the case A101, and a pin A103 for preventing the ball valve A102 from interfering with the side surface of the rotor 100. A valve seat A104 is formed in the case A101.

[0005]

As described above, since the check valve A10 in the conventional hydraulic pump is constituted by the unit member including the case A101 forming the valve seat, the number of parts is increased and the assembling work is also performed. However, there is a problem that the cost becomes high because it takes time.

Further, since it was necessary to form the valve unit accommodating portion 110a for inserting the case A101, an extra space is required accordingly, and the side plate 10 is required.
There was a problem that 2 became large. The present invention has been made in view of the above problems, and an object of the present invention is to provide a hydraulic pump for a power transmission device, which can simplify the assembly work and can make the entire device compact.

[0007]

In order to achieve the above object, a hydraulic pump for a power transmission device according to the present invention includes a rotor that rotates in conjunction with any one of a driving member and a driven member, and a side surface of the rotor. A casing that integrally includes an annular side plate that slidably contacts and that rotates in conjunction with the other while accommodating the rotor, a pump chamber that is formed between the casing and the rotor, and that is formed on the side plate and has one end. Is connected to the pump chamber, and the other end is provided with a plurality of hydraulic oil passages that open to the sliding contact surface with the rotor, and the hydraulic pressure in the pump chamber generated according to the rotational speed difference between the rotor and the casing. In a hydraulic pump for a power transmission device that transmits torque between the two via a valve, a plurality of valve seats formed directly on the side plate and hydraulic oil are allowed to flow only in a predetermined direction. Arranged freely seated on the valve seat in a state, the ball valve to reach the side face of the rotor, is formed on the other opening side of the hydraulic fluid passage, an annular groove connecting the valve seats,
And a snap ring which is fitted into the annular groove and prevents the ball valve from interfering with the side surface of the rotor while allowing the ball valve to operate.

[0008]

According to the hydraulic pump for a power transmission device having the above structure, since the valve seat is directly provided in the hydraulic oil passage of the side plate, it is not necessary to provide a separate case for forming the valve seat. The step of assembling the case can also be omitted. In addition, an annular groove that is formed on the other end opening side of each hydraulic oil passage and connects between the valve seats, and is fitted into the annular groove,
Since the ball valve is provided with a snap ring that prevents it from interfering with the side surface of the rotor while allowing the operation of the ball valve, it is possible to prevent a plurality of ball valves arranged on the same circumference from falling off. This can be done with a single work of mounting the members. .

[0009]

Embodiments will be described in detail below with reference to the accompanying drawings showing embodiments. FIG. 2 is a cross-sectional view showing a driving force transmission device for a four-wheel drive vehicle that employs a hydraulic pump according to an embodiment of the present invention. In the following description, the left and right sides of the drawing are referred to as left and right.

Referring to FIG. 1, this driving force transmitting device is
A housing 1 and a hollow rotary cylinder shaft 2 which is rotatable relative to the housing 1 and is movable in the axial direction.
And a vane pump 3 as the hydraulic pump and a multi-plate clutch 4 which are respectively interposed between the housing 1 and the rotary cylinder shaft 2. The housing 1 is for rotating in unison with a front wheel side drive shaft (not shown) such as a propeller shaft via an input gear portion 11a.
It includes a housing 11, a second housing 12, and a third housing 13. The first housing 11 and the second housing 12 are integrally rotatably connected by a bolt 1a. The first housing 11 and the third housing 13 are integrally rotatably connected by a bolt 1b. First
By the space surrounded by the housing 11, the second housing 12, the third housing 13, the rotary cylinder shaft 2, and the like,
An accommodation chamber 8 for accommodating the vane pump 3 and the multi-plate clutch 4 is formed. The spline portion 43d provided on the inner circumference of the operating member 43 is rotated in conjunction with a rear wheel side drive shaft (not shown) such as a differential side shaft.

The vane pump 3 is provided with a casing 30 that rotates in conjunction with the front-wheel-side drive shaft (not shown) and a rotor 31 housed in the casing 30, and the rotation between the casing 30 and the rotor 31. It is for transmitting torque according to the speed difference. The casing 30 of the vane pump 3 includes the third housing 13, which also serves as a right side plate, and the third housing 13.
In addition, the side plate 9 that holds the rotor 31 therebetween and the cam ring 32 that is arranged on the outer periphery of the rotor 31 and that divides the plurality of pump chambers CH between the rotor 31 and the side plate 9 constitute a main part. Third housing 13, cam ring 32
The side plate 9 and the side plate 9 are integrally rotatably connected by a bolt 37.

The rotor 31 is rotated via the hollow rotary cylinder shaft 2, the cam mechanism 5, and the actuating member 43 in conjunction with the rear wheel side drive shaft (not shown). A male spline portion 2h that is spline-coupled to the rotor 31 of the vane pump 3 is formed in the intermediate portion of the outer periphery of the rotary cylinder shaft 2. A plurality of vanes 34, which are pressed against the inner surface of the cam ring 32 by the compression coil spring 33 and partition the pump chamber CH into two working chambers H1 and H2 (see FIG. 3), project from the accommodation groove on the outer periphery of the rotor 31. ..

As shown in FIGS. 1 and 3, the vane 34 has an orifice 34 which allows oil to flow between the two working chambers H1 and H2 partitioned by the vane 34.
a is provided. Further, groove portions 31a and 31b are provided on both side surfaces of the rotor 31 so that the lower portions of the housing grooves of the vanes 34 communicate with each other. These grooves 31
a and 31b are provided with two working chambers H1 and H1 via separate working oil passages 38a and 38b built in the side plate 9.
It is in communication with 2. That is, the two working chambers H1 and H
The pressure oil from the working chamber H1 (H2) on the higher pressure side of 2 works to press the vane 34 toward the inner peripheral wall of the cam ring 32, and the adhesion of the vane 34 to the inner peripheral wall of the cam ring 32 is enhanced. Has been. In each of the hydraulic oil passages 38a and 38b, there is provided a check valve A that allows only the flow of oil to the lower side of the vane (only one is shown in FIG. 1).
Low pressure side working chamber H2 (H1) of H2 and groove 31
One of the check valves provided in the hydraulic fluid passage connecting a and 31b is closed to prevent the pressure in the low pressure side working chamber H2 (H1) from increasing.

Next, the check valve A in this embodiment will be described in detail with reference to FIG. The check valve A seats on a plurality of valve seats A1 formed directly on the same circumference of the side plate 9 and on each valve seat A1 while allowing hydraulic oil to flow only in a predetermined direction described later. Arranged freely,
The ball valve A2 facing the side surface of the rotor 31 and the ball valve A2 are operated while the ball valve A2 is allowed to operate.
The main part is constituted by the snap ring A3 that prevents the interference with the side surface of the.

The valve seat A1 is formed in a tapered shape by setting a large diameter on the rotor 31 side of the hydraulic oil passage 380a. The ball valve A2 has a tapered valve seat A.
By seating at 1, the hydraulic oil passage 38a is closed, and as shown by the two-dot chain line a in FIG.
By slightly moving to the rotor 31 side of a, only the flow of the hydraulic oil from the high-pressure working chamber H1 (H2) is allowed. The snap ring A3 is press-fitted into the annular groove A4 and is arranged substantially concentrically with the side plate 9, so that the ball valve A2 does not interfere with the rotor 31 in a state where the movement of the ball valve A2 is acceptable. To prevent. The annular groove A4 is formed by cutting out the hydraulic oil passage 380a from the rotor 31 side to the hydraulic oil passage 380a side, and connects the valve seats A1.

Referring to FIG. 2, the multi-plate clutch 4 has a first
A plurality of outer plates 41 spline-coupled to the inner peripheral surface of the housing 11, the actuating member 43 spline-engaged with the rear wheel side drive shaft and axially movable, and an involute groove machined in the actuating member 43. Is fitted into the spline groove 43e such as
The inner plates 42, which are interleaved with one another, and the second
The disc spring 44 is interposed between the housing 12 and the actuating member 43 and urges the plates 41 and 42 in a direction in which they separate from each other. An output side female spline portion 43d, which is spline-coupled to the rear wheel side drive shaft (not shown), is formed on the inner peripheral portion of the operating member 43. Actuating member 43
A retaining ring 40 having a spline portion on its outer peripheral portion is fitted into the spline groove 43e of the spline groove 4e.
It is in contact with the dead end part on the right side of 3e. The retaining ring 40 holds the inner plate 42 and the outer plate 41, which are alternately combined with each other, between the retaining ring 40 and the second housing 12, and the inner plate 42 is moved along with the movement of the operating member 43 to the left. And outer plate 41
It is for pressing both of them.

The actuating member 43 is connected to the rotary cylinder shaft 2 via the cam mechanism 5. Here, the operating member 43 is connected to the rotary cylinder shaft 2 in a state of being movable in the axial direction and relatively rotatable by a predetermined twist angle. Referring also to FIG. 1, the cam mechanism 5 includes a circumferential groove 51 on the actuating member 43 side and a flange-shaped cam member 52 integrally formed at the left end of the rotary cylinder shaft 2, and between them. 55 balls
Are arranged. The circumferential groove 51 and the cam member 52 are each formed in a corrugated shape along the circumference, and when relative displacement in the circumferential direction occurs between them, the ball 55 is twisted between the two and the actuating member 43. To move to the left in the axial direction. The cam mechanism 5 may be composed of a pair of cam surfaces formed in a corrugated shape along the circumference. Further, in that case, the operating member 43 and the rotary cylinder shaft 2
They may be directly formed on the mutual contact surfaces.

Reference numerals 65, 66 and 67 are metal members for reducing sliding resistance. The metal 66 is prevented from rotating by bolts 37. 68 is a seal member. Next, the function of the vane pump 3 will be described with reference to FIG. For example, when the rear-wheel-side drive shaft rotates faster than the front-wheel-side drive shaft while the front wheels are about to lock during braking, the rotor 31 rotates relatively faster than the cam ring 32. That is, the rotor 31
As shown in FIG. 3 (3A), the vane 34 rotates relatively clockwise and the vane 34 advances toward one working chamber H1. At this time, the orifice 34 provided in the vane 34
Since a has a small diameter, the oil moves from one working chamber H1 to the other working chamber H2 with outflow resistance. As a result, a high pressure is generated in the one working chamber H1, and the high pressure is applied to the one working chamber H1 surrounded by the vanes 34 and the cam ring 32.
1 acts as a piston pressure to serve as a torque transmission medium, and torque is transmitted from the rotor 31 to the cam ring 32.
Therefore, the brake torque from the rear wheel that is not locked is also transmitted to the front wheel that is likely to lock, and the braking force for the road surface is secured.

The above pressure increases as the rotational speed difference between the rotor 31 and the cam ring 32 increases, and the rotational speed difference between the front wheel side drive shaft and the rear wheel side drive shaft increases. The corresponding torque is transmitted. On the other hand, FIG. 3 (3B)
When the front wheels slip and the front-wheel-side drive shaft rotates faster than the rear-wheel-side drive shaft, the cam ring 32 causes the rotor 3 to rotate.
It shows a state of rotating clockwise relative to 1. In this case, since the vane 34 advances toward the other working chamber H2, a high pressure is generated in the other working chamber H2, and the high pressure is transmitted from the front wheel side drive shaft to the rear wheel side drive shaft via this high pressure. Torque is transmitted. That is, torque is transmitted from the front-wheel drive shaft on the slipped side to the rear-wheel drive shaft on the non-slip side, torque is automatically distributed, and a grip force on the road surface is secured.

In the above operation, since the ball valve A2 does not interfere with the side surface of the rotor 31 by the snap ring A3, the valve seat A1 is provided directly in the hydraulic oil passage 380a.
The ball valve A2 can be attached to this. Therefore, in this embodiment, since it is not necessary to provide a case of a separate member to form the valve seat, the number of parts is reduced, the labor of assembly work is saved, and the cost can be significantly reduced. The effect of can be produced.

Particularly, according to this embodiment, since the snap ring A3 which is press-fitted into the annular groove A4 is employed, it is possible to prevent a plurality of ball valves A2 arranged on the same circumference from falling off. As a result of being able to carry out the work of mounting the members once, there is an advantage that the labor of the assembling work can be further reduced and the manufacturing cost can be reduced. Further, since the valve seat A1 can be directly formed in the hydraulic oil passage 380a, it is not necessary to take an extra space by that amount, and there is an advantage that the side plate 9 can be downsized.

Next, the function of the cam mechanism 5 will be described.
A casing 30 that rotates integrally with the housing 1 when the difference in rotational speed between the front-wheel-side drive shaft and the rear-wheel-side drive shaft, that is, the difference in rotational speed between the housing 1 and the rotary cylinder shaft 2 is small; Since the differential with the rotor 31 rotating integrally with the rotary cylinder shaft 2 is also small, the hydraulic pressure difference between the working chambers H1 and H2 is also small, and the force for limiting the differential between the casing 30 and the rotor 31 is also small. As a result, the disc spring 44 causes the actuating member 43 to move the actuating member 43 against the force of the relative rotation of the rotary cylinder shaft 2 and the differential member 43.
The force to push in the direction of shut off overcomes, and multi-plate clutch 4
Remains blocked. As a result, the vane pump 3 transmits torque between the two.

On the other hand, when the rotational speed difference becomes larger than a predetermined value, the differential between the casing 30 and the rotor 31 also becomes large, and the hydraulic pressure difference between the working chambers H1 and H2 also becomes large. The force to limit the differential is also increased. As a result, the force of the relative rotation of the rotary cylinder shaft 2 and the differential member 43 overcomes the biasing force of the disc spring 44, and the actuating member 43 is pressed by the cam mechanism 5 in the connecting direction of the multi-plate clutch 4. .. As a result, the front wheel side drive shaft and the rear wheel side drive shaft can be directly connected, the transmission torque can be raised proportionally to the increase in the rotational speed difference, and the transmission torque can be rapidly increased. Therefore, it can also be used as a limited slipped differential.

Moreover, since the above-mentioned rapid increase in torque is mechanically performed via the cam mechanism 5 and is not caused by an explosive increase in internal pressure unlike the viscous coupling, the viscous coupling is It is possible to solve the problem of deterioration of durability due to the excessive increase in internal pressure. Thus, the drawbacks of the viscous coupling and hydraulic pump type devices can be solved at once.

In particular, in this embodiment, since the transmission of high torque is performed with the vane pump 3 completely bypassed, the load on the vane pump 3 can be reduced,
As a result, the constituent members of the vane pump 3, such as the side plate, can be made thinner, and the device can be made even smaller and lighter. In addition, by changing the transmission characteristics of the cam mechanism 5 and the biasing force of the disc spring 44, the multi-disc clutch 4
It is possible to change the pressing force applied to, so that the rise of the transmission torque can be adjusted so as to start in a region where the rotational speed difference is relatively small.

Further, both plates 4 of the multi-plate clutch 4
Since 1 and 42 are arranged at the outer position of the vane pump 3, the axial dimension of the entire apparatus can be shortened. Moreover, the sliding resistance can be reduced by the metal members 65, 66, 67, which reduces the friction torque,
The transmission torque between both drive shafts, especially in the low speed rotation range,
It can be greatly reduced. Further, the members that transmit a large torque are only the first housing 11 and the actuating member 43, and the materials of the second housing 12 and the third housing 13 are reduced to castings, aluminum materials, etc. The ribs can be formed into a rib shape to reduce the strength, and the weight and cost of the device can be reduced.

The present invention is not limited to the above-described embodiment, but is used for transmitting torque between the left front wheel drive shaft and the right front wheel drive shaft, or the left rear wheel drive shaft and the right rear wheel drive, for example. It may be used for transmitting torque to and from the shaft. Further, various design changes can be made without changing the gist of the present invention, such as employing the hydraulic pump of the present invention in a power transmission device other than the driving force transmission device for a four-wheel drive vehicle.

[0028]

As described above, according to the hydraulic pump for a power transmission device of the present invention, since the valve seat is directly provided in the hydraulic oil passage of the side plate, a case of another member is formed to form the valve seat. There is no need to provide it. Therefore, in the present invention, since the number of parts is reduced and the labor of assembling work can be saved, it is possible to achieve the unique effect that the cost can be significantly reduced.

Further, since the snap ring press-fitted into the annular groove is adopted, it is possible to prevent the several ball valves arranged on the same circumference from falling off by one mounting operation of one member. As a result, there is an advantage that the labor of assembling work can be further reduced and the manufacturing cost can be reduced. Moreover, since the valve seat can be formed directly in the hydraulic oil passage,
There is also an advantage that it is not necessary to take an extra space and the side plate can be downsized.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a main part of a vane pump as a hydraulic pump according to an embodiment of the present invention.

FIG. 2 is a sectional view of a hydraulic pump for a power transmission device according to an embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view showing the operation of a vane pump.

FIG. 4 is an enlarged sectional view of a main part of a conventional example.

[Explanation of symbols]

 3 Vane pump (hydraulic pump) 30 Casing A Check valve A1 Valve seat A2 Ball valve A3 Snap ring A4 Annular groove

Claims (1)

[Claims] 1. A rotor, which rotates in conjunction with either a driving member or a driven member, and an annular side plate, which is in sliding contact with the side surface of the rotor, and which integrally rotates in a state of accommodating the rotor. A casing, a pump chamber formed between the casing and the rotor, and a plurality of operations formed in the side plate, one end of which communicates with the pump chamber and the other end of which opens in a sliding contact surface with the rotor. In a hydraulic pump for a power transmission device, which is provided with an oil passage and transmits torque between the rotor and the casing via hydraulic pressure in the pump chamber generated according to a difference in rotational speed between the rotor and the casing, the hydraulic pump is directly formed on the side plate. Multiple valve seats, a ball valve that is seatably mounted on each valve seat while allowing the hydraulic oil to flow only in a predetermined direction, and faces the side surface of the rotor, and each hydraulic oil. An annular groove formed between the valve seats on the other end opening side, and a snap ring that is fitted into the annular groove and that prevents the ball valve from interfering with the side surface of the rotor while allowing the ball valve to operate. A hydraulic pump for a power transmission device, which is characterized by being provided.