JPH0596565U - Hydraulic power transmission coupling - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] For hydraulic power transmission joints used to distribute the driving force of a vehicle, prevent galling, reduce friction torque, and simplify plunger machining. The purpose is to [Structure] A recess 31 is formed at the tip of the plunger 8,
The roller 32 is inserted into the recess 31.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a hydraulic power transmission joint used for distributing a driving force of a vehicle.

[0002]

[Prior Art]

 The present applicant has proposed the following hydraulic power transmission joint in, for example, Japanese Patent Application No. 02-37921. That is, the hydraulic power transmission joint is provided between the input / output shafts that can rotate relative to each other, is connected to the one shaft, and has a cam housing having a cam surface having two or more ridges on the inner surface, and the other one. And a rotor member that is rotatably housed in the cam housing and that forms a plurality of plunger chambers, and reciprocates under the pressure of a return spring in each of the plurality of plunger chambers. A plurality of plungers that are freely stored and that are driven by the cam surface when the shafts rotate relative to each other; suction and discharge holes that open to the surface of the rotor member and communicate with the plunger chamber; It slides rotatably on the surface of the member, and when the relative rotation directions of both shafts are switched, it can rotate with the cam housing by a predetermined angle. A valve body arranged to operate the suction valve or the discharge valve according to the positional relationship with the suction and discharge holes; and means for generating a flow resistance in response to the discharge pressure generated by driving the plunger. The torque is transmitted according to the rotational speed difference of the shaft.

[0003]

[Problems to be solved by the device]

 However, in such a conventional hydraulic power transmission joint, as shown in FIG. 4, the tip of the plunger 54 pushed into the rotor 53 by the cam surface 52 formed in the cam housing 51 has a cam surface. Since the cam housing 51 and the plunger 54 have a sliding friction due to the curved cross section corresponding to 52, when the cam surface 52 pushes the plunger 54 against the return spring 55, The excessive surface pressure causes galling, and since the friction coefficient is large, the friction torque is increased, and the plunger 54 is not easily machined.

The present invention has been made in view of the above-mentioned conventional problems, and prevents the occurrence of galling by using rolling friction as the friction between the cam housing and the plunger to prevent friction torque. It is an object of the present invention to provide a hydraulic power transmission joint in which the plunger is easily processed.

[0005]

[Means for Solving the Problems]

 To achieve the above object, the present invention provides a cam housing which is provided between relatively rotatable input / output shafts, is connected to the one shaft, and has a cam surface having two or more ridges, and the other one. And a rotor that is rotatably housed in the cam housing and that forms a plurality of plunger chambers, and the plunger chambers are reciprocally movable under the pressure of a return spring. And a means for generating flow resistance by the flow of the discharge oil due to the driving of the plungers. A hydraulic power transmission joint that transmits torque according to a difference in rotational speed of a shaft, in which a recess is formed at the tip of the plunger and a roller is inserted into the recess. That.

[0006]

[Action]

 In the present invention, since the recess is formed at the tip of the plunger and the roller is inserted into the recess, when the plunger is pushed into the rotor by the cam surface of the cam housing, the roller rotates. The friction of the plunger is rolling friction.

Therefore, since excessive surface pressure is not applied to the cam surface and the plunger, it is possible to prevent galling of the cam surface and the plunger. Further, since the friction coefficient becomes small, the friction torque can be reduced. Further, unlike the conventional case, it is not necessary to form the tip of the plunger so that its cross section is curved, so that the plunger can be easily processed.

[0008]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 are views showing an embodiment of the present invention. First, the structure will be described. In FIGS. 1 to 3, reference numeral 1 is a cam having a cam surface 2 having two or more ridges on its inner surface. The cam 1 is connected to an output shaft 3 and Rotate as a unit. The cam 1 is fixed to the cam housing 4, and the cam housing 4 rotates integrally with the cam 1.

Reference numeral 5 denotes a rotor rotatably housed in the cam housing 4. The rotor 5 is coupled to the input shaft 6 and rotates integrally with the input shaft 6. A plurality of plunger chambers 7 are formed in the rotor 5 in the axial direction, and a plurality of plungers 8 are slidably accommodated in the plunger chamber 7 via return springs 9. Further, the rotor 5 is formed with a plurality of suction / discharge holes 10 so as to communicate with the respective plunger chambers 7.

Reference numeral 11 denotes a rotary valve (valve body) having a suction port 12, a suction passage 13 and a discharge port 14 formed on the front surface thereof, and a communication groove 15 is formed on the back surface of the rotary valve 11. The communication groove 15 communicates with the discharge port 14, and a lid member 16 is provided in close contact with the communication groove 15. Reference numeral 17 is an orifice as a flow resistance generating means, and the orifice 17 is formed in the radial valve 11 in the radial direction so as to connect the discharge port 14 and the suction passage 13.

Further, the rotary valve 11 has a positioning projection 19 that engages with a notch 18 formed in the inner circumference of the cam housing 4. The rotary valve 11 constitutes a timing member that determines the opening / closing timing of the intake / discharge hole 10, and the notch 18 and the protrusion 19 constitute a positioning mechanism that regulates the position correlation between the cam 1 and the rotary valve 11.

When the plunger 8 is in the intake stroke, the intake port 12 of the rotary valve 11 and the intake / exhaust hole 10 of the rotor 5 communicate with each other, and the intake passage 13, the intake port 12, and the intake / exhaust of the rotor 5 are connected. Oil can be sucked into the plunger chamber 7 through the hole 10. When the plunger 8 is in the discharge stroke, the relationship is the reverse of the suction stroke, and the suction / discharge hole 10 of the rotor 5 communicates with the communication groove 15 via the discharge port 14 of the rotary valve 11, and the suction port 12 is closed. It will be in a state of being.

Reference numeral 20 is a thrust block that rotates integrally with the cam housing 4, and supports the input shaft 6 via a bearing 21. A needle bearing 22 is interposed between the thrust block 20 and the rotary valve 11, and the friction torque on the needle bearing 22 side is set to be smaller than the friction torque between the rotor 5 and the rotary valve 11. Therefore, when the direction of the differential rotation changes, the rotary valve 11 turns around together with the rotor 5, rotates until the positioning projection 19 of the rotary valve 11 comes into contact with the notch 18 of the cam housing 4, and then becomes integral with the cam housing 4. To rotate. As a result, the intake / discharge hole 10 is forcibly opened / closed at a predetermined timing even during normal rotation or reverse rotation.

Reference numeral 23 denotes an accumulator piston that rotates integrally with the cam housing 4, and the accumulator piston 23 moves according to the internal pressure. A return spring 25 is interposed between the accumulator piston 23 and the retainer 24. A recess 31 is formed at the tip of the plunger 8, and a roller 32 is inserted into the recess 31.

Therefore, when the cam surface 2 of the cam 1 pushes the plunger 8 into the plunger chamber 7, the roller 32 rotates, and the friction between the cam surface 2 and the plunger 8 becomes rolling friction. 26 is an oil seal, 27 is a stopper ring, 28 is a bolt, and 30 is a needle bearing. Next, the operation will be described.

When there is no rotation difference between the cam 1 and the rotor 5, the plunger 8 does not operate and torque is not transmitted. At this time, the plunger 8 is pressed against the cam surface 2 by the return spring 9. Next, when the rotation of the input shaft 6 having the rotor 5 rotates faster than the output shaft 3 having the cam 1 and a difference in rotation occurs between the input and output shafts, the plunger 8 in the discharge stroke causes the cam surface of the cam 1 to move. It is pushed axially by 2.

Therefore, the plunger 8 pushes the oil in the plunger chamber 7 from the suction / discharge hole 10 to the discharge port 14 of the rotary valve 11. The oil pushed out to the discharge port 14 is supplied to the suction passage 13 through the communication groove 15 and the orifice 17. At this time, the hydraulic pressure in the communication groove 15, the discharge port 14 and the plunger chamber 7 rises due to the resistance of the orifice 17, and a reaction force is generated in the plunger 8. By rotating the cam 1 against the plunger reaction force, torque is generated, and torque is transmitted between the cam 1 and the rotor 5.

Further, when the cam 1 rotates, an intake stroke occurs, and the intake / discharge hole 10 and the intake port 12 communicate with each other, so that the oil in the intake passage 13 enters the plunger chamber 7 via the intake port 12 and the intake / discharge hole 10. Inhaled, the plunger 8 returns along the cam surface 2 of the cam 1. Here, in this embodiment, since the recess 31 is formed at the tip of the plunger 8 and the roller 32 is inserted into the recess 31, the friction between the cam 2 and the plunger 8 becomes rolling friction.

Therefore, since excessive surface pressure is not applied to the cam surface 2 and the plunger 8, it is possible to prevent galling of the cam surface 2 and the plunger 8. Further, since the friction coefficient becomes small, the friction torque can be reduced. Further, unlike the conventional case, it is not necessary to form the tip of the plunger 8 so that the cross section thereof has a curved shape, so that the plunger 8 can be easily processed.

[0020]

[Effect of the device]

 As described above, according to the present invention, since the recess is formed in the tip of the plunger and the roller is inserted into the recess, the friction between the cam and the plunger can be rolling friction. It is possible to prevent galling, reduce friction torque, and facilitate machining.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a hydraulic power transmission joint of the present invention.

3 is a sectional view taken along the line AA of FIG.

FIG. 4 is an explanatory diagram of problems

[Explanation of symbols]

 1: Cam 2: Cam surface 3: Output shaft 4: Cam housing 5: Rotor 6: Input shaft 7: Plunger chamber 8: Plunger 9: Return spring 10: Suction / discharge hole 11: Rotary valve 12: Suction port 13: Suction path 14: Discharge port 15: Communication groove 16: Lid member 17: Orifice 18: Notch 19: Protrusion 20: Thrust block 21: Bearing 22: Needle bearing 23: Accumulator piston 24: Retainer 25: Return spring 26: Oil seal 27: Stopper ring 28: Bolt 30: Needle bearing 31: Recessed portion 32: Roller

Claims (1)

[Scope of utility model registration request] 1. A cam housing provided between relatively rotatable input / output shafts, connected to said one shaft, and having a cam surface having two or more ridges, and connected to said other shaft. A rotor that is rotatably housed in the cam housing and forms a plurality of plunger chambers; and a plurality of plunger chambers that are housed in each of the plurality of plunger chambers so as to be reciprocally movable under the pressure of a return spring. A plurality of plungers driven by the cam surface when the two shafts rotate relative to each other; In the hydraulic power transmission joint for transmitting the force, a recess is formed at the tip of the plunger, and a roller is inserted into the recess.