JPH03244835A - Hydraulic power transmission joint - Google Patents

Abstract

PURPOSE:To simplify both inlet and discharge valves in structure by installing a valve element, provided with plural units of inlet ports and discharge, in a rotor member, and constituting it to produce flow resistance in space between a high pressure chamber interconnected to these discharge ports and a low pressure chamber in a joint. CONSTITUTION:When a rotational difference is produced in an internal between a cam 1 and a rotor 4, a plunger 6 is pressed in the axial direction by a cam surface 2. Therefore the plunger 6 forces out oil in a plunger chamber 5 to a high pressure chamber 16 via a rotary valve 10, a discharge port 12A and a discharge passage 12B, while an inlet-discharge combined port 8 is closed by the rotary valve 10. A flow resistance of oil is produced by an orifice 18 lying between the high pressure chamber 16 and a low pressure chamber 20 and thereby reaction is produced in the plunger 6 as well, so that torque is transferred to an interval between the cam 1 and the rotor 4. When the plunger 6 comes to an inlet stroke, oil in the low pressure chamber 20 is taken into the plunger chamber 5 by way of an inlet passage 11B and an inlet port 11A of the rotary valve 10. Owing to the said constitution, both inlet and discharge valves are simplified in terms of structure.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hydraulic power transmission joint used for distributing driving force in a vehicle.

[Prior art] As a conventional hydraulic power transmission joint, for example,
No. 2-286838 discloses a first rotating member that is formed integrally with one of the input/output shafts and has a cam surface on the inner circumference, and a first rotating member that is formed integrally with the other input/output shaft and is inserted into the cam surface. a second rotating member; a cam body that is supported by the second rotating member and is adjacent to the cam surface and reciprocates in the radial direction when the rotating member rotates relative to each other; the volume changes as the cam body reciprocates; A device is described that includes a plurality of liquid chambers and a fluid path formed in the second rotating member and connecting the respective fluid chambers via an orifice.

Furthermore, in Japanese Patent Application No. 1-7967, the present applicant proposed a cam housing having a cam surface formed on its inner surface, and a cam housing that was rotatably housed in the cam housing and formed with a plurality of plunger chambers in the axial direction. a rotor, a plurality of plungers housed in a plunger chamber by return springs and reciprocating in the axial direction, a main passage communicating with the plunger chamber via a discharge passage having a discharge valve interposed therebetween; and the main passage. and an oil circulation groove provided in the outer diameter portion of the rotor for communicating the plunger chamber with a suction passage provided with a suction valve, and an oil circulation groove provided in the main passage that moves at a predetermined discharge pressure. an orifice valve having an orifice that is moved by being pressed by a temperature-sensitive deformable member that deforms at a predetermined temperature;
A hydraulic power transmission joint is proposed that includes a needle valve that closes the orifice when the orifice valve moves.

In both, the plunger reciprocates multiple times per revolution of the cam, and a check valve is used as the suction valve.

[Problems to be Solved by the Invention] However, in such a conventional hydraulic power transmission joint, since check valves were used as the intake valve and the discharge valve, there were the following problems.

(1) It required the same number of suction valves and discharge valves as the number of plungers, each consisting of a valve body, a return spring, and a spring retainer, which required a large number of parts and took time to assemble.

In addition, since the contact part (valve seat) with each valve body is located deep inside the hole such as the plunger chamber, it is difficult to process with high precision without sealing defects, and the process is not only time-consuming. , which worsened the yield.

This resulted in high parts and assembly costs, leading to high costs.

(2) When attempting to shorten the length of the joint, the discharge valve must be placed on the inner diameter of the rotor.

As a result, it is necessary to secure a space in the inner diameter of the rotor that is commensurate with the size of the valve body, so the thickness of the shaft is thick.
This results in a joint with a large outer diameter, and there are significant design restrictions.

(3) Also, at the moment the plunger passes over the cam, the residual pressure forces the plunger back and violently collides with the cam, which not only causes loud noise from the joint, but also causes damage to the cam and plunger. The contact part is deformed,
There was a problem with abnormal wear.

Further, although it is possible to prevent the rotation of the plunger by adding a rotation prevention mechanism, there are problems in that the structure becomes complicated and reliability not only decreases but also increases in cost.

(4) Furthermore, when the suction valve is a check valve, it is necessary to use a return spring to prevent the valve from opening due to centrifugal force acting on the valve. There is no problem if all the valves are placed at or near the rotation center of the joint, but in the case of a plunger pump, the same number of valves as plungers are required, making the configuration difficult and the joint itself large. In addition, if the valve's operating direction is on a plane parallel to the joint rotation axis, the valve will not open due to centrifugal force, but it will be pressed against the side wall and create resistance, and the manufacturing process will be difficult and costly. Become. Furthermore, the return spring of the valve needs to be strengthened to some extent in order to respond quickly when opening and closing the valve. As the cracking pressure increases, the following problems also arise.

■Lower filling efficiency.

As oil is insufficiently sucked into the plunger chamber, torque pulsation increases. Also, when refueling, air remains due to insufficient filling of the song.

■Preload is required.

Pre-pressure must be applied to the outer chamber to overcome the cracking pressure of the suction valve and force oil into the plunger chamber. For this reason, the accumulator spring must be set to be strong.

As the accumulator becomes larger, the coupling becomes larger, weighs more, and costs increase. Also, the plunger spring must be set to be strong. If the plunger chamber becomes larger, the coupling becomes larger, weighs more, and costs increase.

It is also necessary to improve the pressure resistance of the oil seal.

In this case, the seal becomes larger and the cost increases. Furthermore, in the case of a structure in which preload is converted into a thrust load, a large thrust load is generated on the rotor due to the return spring and preload of the plunger, and the thrust bearing has a large starting torque due to frictional resistance.

The present invention was made in view of these conventional problems, and aims to reduce the number of parts by simplifying the structure of the suction valve and discharge valve, and to reduce costs by simplifying machining. The purpose is

Another object of the present invention is to simultaneously solve other problems when using check valves for suction and discharge valves, and to provide a hydraulic power transmission joint that is small, lightweight, inexpensive, and highly durable and reliable.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a plunger pump provided between relatively rotatable input and output shafts and driven by a rotational speed difference between the two shafts; A power transmission joint comprising means for generating flow resistance in the discharge path of the pump, and in which the transmission torque between the input and output shafts is controlled by the flow resistance; a cam housing formed with a cam surface having a cam surface; a rotor member connected to the other shaft, rotatably housed within the cam housing, and forming a plurality of plunger chambers; the plurality of plunger chambers; a plurality of plungers, each of which is housed in a reciprocating manner under the pressure of a return spring, and which is driven by the cam surface when the two shafts rotate relative to each other; A suction hole and a discharge hole that communicate with the plunger chamber: are in rotatable and sliding contact with the rotor member and are positioned to be rotatable by a predetermined angle between them and the cam housing, and the relative rotational direction of both shafts is correct. A valve body having a plurality of suction ports and discharge ports that act as suction valves and discharge valves depending on the positional relationship with the suction hole and the discharge hole in both rotation and reverse rotation, and each of the discharge ports as a discharge passage. A high-pressure chamber formed by communicating with each other through a communication passage; a suction passage connecting the suction port and the low-pressure chamber in the joint; and a flow resistance generating means provided at an outlet portion from the high-pressure chamber to the low-pressure chamber. .

[Function] The present invention includes a plunger pump provided between relatively rotatable input and output shafts and driven by a difference in rotational speed between the two shafts, and a means for generating flow resistance in a discharge path of the pump. , a power transmission joint in which the transmission torque between the input and output shafts is controlled by the flow resistance, the cam housing being connected to the one shaft and having a cam surface having two or more ridges on its inner surface; a rotor member connected to the shaft of the cam housing, rotatably housed in the cam housing, and forming a plurality of plunger chambers; reciprocating movement in each of the plurality of plunger chambers under pressure of a return spring; a plurality of plungers that are freely housed and driven by the cam surface when the two shafts rotate relative to each other; a suction hole and a discharge hole that are formed in the rotor member and communicate with the plunger chamber; the rotor member The shaft is rotatably in sliding contact with the cam housing, and is positioned rotatably by a predetermined angle with the cam housing, and is positioned relative to the suction hole and the discharge hole regardless of whether the relative rotation direction of the two shafts is forward or reverse rotation. A valve body having a plurality of suction ports and discharge ports that act as suction valves and discharge valves depending on the relationship; a high pressure chamber formed by communicating each of the discharge ports with a discharge passage through a communication passage; and the suction port. By providing a flow resistance generating means in the suction passage connecting the low pressure chambers in the joint and the outlet section from the high pressure chamber to the low pressure chamber, the structure of the suction valve and discharge valve is simplified, the number of parts is reduced, and machining is easier. , assembly becomes easy and costs can be reduced.

Further, other problems when using check valves for the suction and discharge valves can be solved at the same time, and a hydraulic power transmission joint that is small, lightweight, inexpensive, and highly durable and reliable can be obtained.

Further, since the suction passage, the discharge passage, and the communication passage are formed by providing grooves on the surface of the rotor member or the valve body, machining becomes easy and costs can be further reduced.

[Example] Embodiments of the present invention will be described below based on the drawings.

1 to 6 are diagrams showing one embodiment of the present invention.

First, to explain the configuration, in FIGS. 1 and 2, 1 is a cam with a cam surface 2 having two or more ridges on its inner surface, and the cam 1 is connected to an output shaft or an input shaft. Rotates together with the output shaft or input shaft. Also, cam 1
is fixed to the cam housing 3, and the cam housing 3 rotates together with the cam 1.

A rotor 4 (rotor member) is rotatably housed in the cam housing 3. The rotor 4 is connected to the input shaft or the output shaft, and rotates together with the input shaft or the output shaft.

A plurality of plunger chambers 5 are formed in the rotor 4 in the axial direction, and a plurality of plungers 6 are formed in the plunger chamber 5.
is slidably housed via a return spring 7. The rotor 4 also has multiple suction and discharge ports 8.
is formed.

10 is a suction port 11 communicating with the suction/discharge port 8
A and the suction passage 11B and the discharge port 12A and the discharge passage 12
The rotary valve 10 has a positioning protrusion 14 that engages with a notch 13 formed on the inner circumference of the cam housing 3. Further, a communication passage 15 is formed in the rotor 4 and communicates with the discharge passage 12B, and the communication passage 15 is connected to a high pressure chamber 16 through a passage 15A.
are communicating. An orifice valve 19 having an orifice 18 is movably housed in a housing chamber 4A formed in the rotor 4 via a spring 17. The orifice valve 19 moves to the right when the discharge pressure of the high pressure chamber 16 reaches a predetermined value, and this movement causes the needle valve 2
1 closes the orifice 18. 20 is a low pressure chamber formed in the rotor 4, the low pressure chamber 20 communicates with the plunger chamber 5, the plunger chamber 5 communicates with an oil groove (not shown) formed on the outer diameter of the rotor 4, and the oil groove rotary valve 1
It communicates with the intake passage 11B of No. 0.

22 is a support member that rotates integrally with the cam housing 3, and a ball bearing 2 is provided between the support member 22 and the rotary valve 10 via a disc spring 29 so as to be movable in the axial direction.
3 is interposed.

Here, since the spring load of the disc spring 29 is set larger than the total spring load of the plunger return spring 7 acting on the rotor 4, the differential rotation speed of the joint is low.
When the pressure inside the plunger chamber 5 is low, the thrust load acting on the rotor 4 becomes weaker than the spring load,
The rotary valve 10 is supported by ball bearings 23 in both the axial and radial directions.

Furthermore, as the differential rotation speed of the joint increases, the thrust load acting on the rotor 4 becomes stronger, but it becomes larger than the spring load, so the bearing 23 is pushed to the left in the figure, and the rotary valve 10 is supported. It is supported directly in the axial direction by member 22 .

Therefore, a thrust load greater than the disc spring load is not applied to the ball bearing 23, and a small and inexpensive ball bearing can be used.

By adopting such a support structure, once the differential rotation speed is changed to zero and the differential rotation direction is switched, the friction torque on the Hall bearing 23 side becomes smaller than the friction torque between the rotor 4 and the rotary valve 10. .

Therefore, if the direction of differential rotation changes (Figs. 3 and 4)
The rotary valve 10 rotates with the rotor 4 until the positioning protrusion 14 of the rotary valve 10 contacts the cam housing 3 and the notch 13, and then rotates integrally with the cam housing 3. Thereby, the suction/discharge port 8 is forcibly opened/closed at a predetermined timing even during forward rotation or reverse rotation. Here, rotor 4
A radial bearing 30.31 is formed between the rotary valve 10, the rotor 4, and the cam 1.

As a method of supporting the rotary valve 10, as shown in FIG.
There is a problem in that the rotor 4 moves to the right, creating a gap between it and the rotary valve 10, resulting in no longer generating torque.

Another problem is that the seal length B of the inner diameter of the rotary valve 10 becomes shorter, causing more oil to leak from the high pressure chamber 16, and when the temperature of the joint changes, the change in retorque increases due to changes in the viscosity of the oil. There is also.

24 is an accumulator piston that rotates integrally with the support member 22, and the accumulator piston 24 moves according to internal pressure. In addition, 25 is an oil seal, 26.27
is a stop ring, and 28 is a mounting hole for the input/output shaft.

Next, the effect will be explained.

When there is no difference in rotation between the cam 1 and the rotor 4, the plunger 6 does not operate and no torque is transmitted. Note that at this time, the plunger 6 is pressed against the cam surface 2 by the return spring 7.

Next, when a rotation difference occurs between the cam 1 and the rotor 4, the plunger 6, which is in the discharge stroke, is pushed in the axial direction by the cam surface 2 of the cam 1.

Therefore, the plunger 6 drains the oil in the plunger chamber 5 through the discharge hole 9 and the discharge port 12A of the rotary valve 10.
1 discharge passage 12B1 through the communication passage 15 and passage 15A to the high pressure chamber 16, and the suction/discharge port 8
is forcibly closed by the rotary valve 10 (see FIGS. 5 and 6).

The oil pushed out into the high pressure chamber 16 is supplied to the low pressure chamber 20 through the orifice 18 of the orifice valve 19 . At this time, the oil pressure in the high pressure chamber 16 and the plunger chamber 5 increases due to the resistance of the orifice 18, and a reaction force is generated in the plunger 6. Cam 1 opposes this plunger reaction force.
Torque is generated by rotating the cam 1 and the rotor 4, and the torque is transmitted between the cam 1 and the rotor 4.

Furthermore, when the cam 1 rotates, the plunger 6 enters the suction stroke, and the oil in the low pressure chamber 20 flows into the plunger chamber 5,
The oil is sucked into the plunger chamber 5 through the oil groove, the suction path 11B of the rotary valve 10, the suction port 11A1 and the suction/discharge port 8, and returns along the cam surface 2 of the cam 1 (the fifth
(see Figure 6).

In this embodiment, the suction port IIA and the suction path 11B
Since a rotary valve 10 having a discharge port 12A and a discharge passage 12B is used, the structure of the suction valve and discharge valve is simplified, the number of parts is reduced, and machining and
Assembly becomes easier and costs can be reduced.

Also, just before the plunger 5 gets over the cam 1, the plunger 5. Since no high pressure is applied to the cam 1 and the plunger 5, even if there is partial contact between the cam 1 and the plunger 5, no large rotational force is generated on the plunger 5, and the plunger 5 does not rotate.

Therefore, there is no need for a mechanism to prevent rotation of the plunger 5, and it is possible to prevent a decrease in reliability and an increase in cost due to this mechanism.

Further, since the suction valve is a forced opening/closing valve using the rotary valve 10, the filling efficiency can be increased compared to a check valve, and preload is not required.

As a result, it is possible to reduce the size, weight, and cost of the joint.

Further, depending on the differential rotation direction, the opening/closing timing of the valve relative to the cam 1 can be switched between normal rotation and reverse rotation. Therefore, it can be applied to a driving force distribution joint for four-wheel drive vehicles.

Next, FIGS. 8 and 9 are diagrams showing a second embodiment of the present invention.

In FIGS. 8 and 9, an accumulator piston 35 is slidably provided in a storage chamber 34 at the center of the rotor 4. As shown in FIGS. Therefore, the joint can be made smaller compared to when it is provided outside the rotor 4.

36 is an orifice formed in the rotary valve 10, and the orifice 36 opens to the discharge port 12A and communicates with the suction path 11B.

Therefore, oil flows from the orifice 36 to the suction path 11B.
1 suction port 11A1 returns to the plunger chamber 5 via the suction/discharge port 8. As a result, the internal structure becomes simple and costs can be reduced.

In this embodiment, the hole 8 is provided which serves as both the suction hole and the discharge hole, but it is also possible to provide separate holes.

[Effects of the Invention] As explained above, according to the present invention, the structure of the suction valve and the discharge valve is simplified, the number of parts is reduced, and processing and
Assembly becomes easier and costs can be reduced.

Further, other problems when using check valves for the suction and discharge valves can be solved at the same time, and a hydraulic power transmission joint that is small, lightweight, inexpensive, and highly durable and reliable can be obtained.

Further, since the suction passage, the discharge passage, and the communication passage are formed by providing grooves on the surface of the rotor or the valve body, machining becomes easy and costs can be further reduced.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the first embodiment of the present invention, Fig. 2 is a cross-sectional view thereof, Fig. 3 is an explanatory diagram during normal rotation, Fig. 4 is an explanatory diagram during reverse rotation, Figs. 5 and 6 The figures are each explanatory diagram of the flow of oil, Fig. 7 is an explanatory diagram of the problem when uplift occurs, Fig. 8 is a diagram showing the second embodiment of the present invention, and Fig. 9 is a cross-sectional view thereof. . In the figure, 1...cam, 2...cam surface, 3...cam housing, 4...rotor, 4A...storage chamber, ...plunger chamber, ...plunger... Return spring, ...suction and discharge port, 0...rotary valve, 1A...suction port, IB...suction path, 2A...discharge port, 2B...discharge path, 3...off Notch, 4... Protrusion, 5... Communication path, 5A, Passage, 6... High pressure chamber, 7... Spring, 8... Orifice, 9... Orifice valve, 0... Low pressure chamber, 1 ... Needle valve, 2... Support member, 3... Ball bearing, 4... Accumulator piston, 5... Oil seal, 6.27... Stop ring, 8... Mounting hole, 9... Belleville spring, 0.31... Radial bearing, 2.33... Needle bearing, 4... Storage chamber, 5... Accumulator piston, 6... Orifice.

Claims (6)

[Claims] (1) A plunger pump that is provided between relatively rotatable input and output shafts and is driven by the difference in rotational speed between the two shafts;
The power transmission joint is provided with means for generating flow resistance in the discharge path of the pump, and the transmission torque between the input and output shafts is controlled by the flow resistance, the power transmission joint being connected to the one shaft and having two or more a cam housing formed with a cam surface having ridges; a rotor member connected to the other shaft, rotatably housed within the cam housing, and forming a plurality of plunger chambers; the plurality of plungers; a plurality of plungers that are housed in each of the chambers so as to be reciprocally movable under the pressure of a return spring, and that are driven by the cam surface when the two shafts rotate relative to each other; a suction hole and a discharge hole communicating with the jar chamber; rotatably slidingly contact the rotor member, and positioned rotatably by a predetermined angle between the cam housing, and the relative rotation direction of the two shafts being normal rotation; In either case of reverse rotation, a valve body having a plurality of suction ports and discharge ports that act as suction valves and discharge valves depending on the positional relationship with the suction hole and the discharge hole; and a valve body that connects each of the discharge ports with a discharge passage A high pressure chamber formed in communication with each other, a suction passage connecting the suction port and the low pressure chamber in the joint, and a flow resistance generating means provided at an outlet from the high pressure chamber to the low pressure chamber. Hydraulic power transmission coupling. (2) The hydraulic power transmission according to claim 1, wherein the discharge passage and the communication passage are formed by providing grooves in the sliding surface of the valve body or the valve body of the rotor member. Fittings. (3) A hydraulic power transmission according to claim 1, wherein a radial bearing is formed between the valve body and the rotor member, and the communication path is formed adjacent to the radial bearing. Fittings. (4) At least when the relative rotational direction of the two shafts is switched, the friction torque between the valve body and the rotor member is greater than the friction torque between the valve body and the support member supported by the cam housing. The hydraulic power transmission joint according to claim 1, characterized in that: (5) The hydraulic power transmission joint according to claim 1, wherein an accumulator piston is provided in the center of the rotor member. (6) The hydraulic power transmission joint according to claim 1, wherein the valve body is provided with an orifice that opens to the discharge port of the valve body.