JPH0632766U - Hydraulic power transmission coupling - Google Patents

Abstract

(57) [Abstract] [Purpose] Prevents damage to O-rings and oil seals for hydraulic power transmission joints used to distribute vehicle driving force.
The purpose of the present invention is to prevent locking and oil leakage due to the fall of the accumulator piston, to achieve size and weight reduction, to reduce the number of parts, and to reduce cost. [Structure] A bellows that absorbs the volume expansion of the enclosed oil enclosed in the joint is fixed to a mouthpiece member having a communication hole communicating with the inside of the joint.

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]

 Examples of conventional hydraulic power transmission joints include the following (see Japanese Patent Application No. 2-184737). That is, this hydraulic power transmission joint is provided with a hydraulic pump driven by the rotational speed difference between the first and second rotating members capable of relative rotation, and means for generating flow resistance in the discharge passage of the hydraulic pump, A hydraulic power transmission joint in which the transmission torque between the first and second rotating members is controlled by the flow resistance, wherein an oil is enclosed in the joint and an accumulator piston for absorbing a volume change of the enclosed oil is provided. In a hydraulic power transmission joint, multiple springs that press the accumulator piston and retainers that hold and fix the springs are provided, and the retainers are directly fixed to the joint outer cylinder.

In Japanese Patent Application No. 2-16380, the following hydraulic power transmission joint is proposed. In other words, in this hydraulic power transmission coupling, the accumulator piston has a ring shape, and the outer diameter portion of the piston is concentrically and axially movable with respect to the first or second rotating member, and the piston The inner diameter portion extends to the second or first rotating member and is concentrically and axially movable relative to the second or first rotating member and is rotatable relative to the second or first rotating member, and an axial seal is provided on the outer diameter portion of the piston. In addition to providing a seal member for performing the above, a seal member for providing an axial and rotational seal with the second or first rotating member is provided in the inner diameter portion.

Further, Japanese Patent Application No. 2-74479 discloses the following hydraulic power transmission joint. In other words, this hydraulic power transmission joint is equipped with an accumulator piston that absorbs the volume change of the enclosed oil enclosed inside the joint, a return spring that presses the accumulator piston, and a retainer that holds the return spring. A communication hole that connects the chamber defined by the above and the outside of the joint is provided at a position that is at least outside the outer diameter of the accumulator piston of the retainer.

[0005]

[Problems to be solved by the device]

 However, in any of these conventional hydraulic power transmission couplings, when used in automobiles under severe environmental conditions, they are installed inside the gear carrier of the final reducer or inside the transfer case. However, if it is installed between the final reduction gear and the propeller shaft or between the propeller shaft and the transfer case, the following problems will occur.

(1) The O-ring and the oil seal are easily damaged by muddy water and dust. (2) If the O-ring and the shaft part of the oil seal are left for a long period of time, rust is generated, and the sliding surface of the O-ring and the lip part of the seal are easily damaged. (3) If the axial length of the accumulator piston is not long, it may fall over and lock, or oil may leak more easily than the seal.

(4) Since the internal pressure rises due to the rotation of the joint, it is necessary to set the force of the spring strongly, which results in a large size and a heavy weight. (5) The number of parts is large, and man-hours are required for assembly and management, which is expensive. The present invention has been made in view of the above conventional problems, and prevents damage to the O-ring and the oil seal, prevents lock and oil leakage due to the fall of the accumulator piston, and reduces size and weight. It is an object of the present invention to provide a low-cost hydraulic power transmission joint with a small number of parts.

[0008]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention provides a hydraulic pump which is provided between input / output shafts that can rotate relative to each other, and is driven by a differential rotation of both shafts, and a flow resistance provided at an outlet of the hydraulic pump. In a hydraulic power transmission joint that includes a generator and that transmits torque according to the rotational speed difference between the two shafts, a communication hole that communicates with the bellows that absorbs the volume expansion of the enclosed oil enclosed inside the joint is provided with a communication hole. It is fixed to the formed base member.

Further, the present invention includes a hydraulic pump provided between the input and output shafts that can rotate relative to each other, and driven by differential rotation of the both shafts, and a flow resistance generating means provided at an outlet of the hydraulic pump. In the hydraulic power transmission joint that transmits torque according to the rotational speed difference between the two shafts, a retainer is fixed to the outside of the joint to define a hydraulic chamber that communicates with the inside of the joint, and the volume of oil filled in the hydraulic chamber is defined. A bellows that is compressed by expansion is fixed and stored in a retainer.

Further, the present invention comprises a hydraulic pump provided between the input and output shafts that are relatively rotatable and driven by the differential rotation of the both shafts, and a flow resistance generating means provided at the outlet of the hydraulic pump. In the hydraulic power transmission joint that transmits torque according to the rotational speed difference between the two shafts, one of the input / output shafts is provided with a hydraulic chamber communicating with the inside of the joint, and the volume expansion of the enclosed oil is performed in the hydraulic chamber. The bellows to be compressed is fixed and stored in the base member.

Further, according to the present invention, as the material of the bellows, a metal having excellent heat resistance and oil resistance is used, and the plate thickness is formed to a predetermined thin thickness.

[0012]

[Action]

 According to the hydraulic power transmission joint of the present invention having such a configuration, when the temperature of the sealed oil sealed inside the joint rises due to the operation of the joint and it thermally expands, the bellows absorbs this thermal expansion. To do. In this case, the O-ring and the oil seal do not move and are constant, so that the O-ring and the oil seal are less likely to be damaged and the durability can be improved.

Further, the accumulator piston is not necessary, oil leakage due to wear is eliminated, and locking due to falling does not occur. Moreover, since a return spring for the accumulator piston is not necessary, it is possible to reduce the size and weight. Furthermore, the number of parts is reduced, and the number of man-hours required for assembly and management is also reduced, and the cost can be reduced.

[0014]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment of the present invention. First, the structure will be described. In FIG. 1, reference numeral 1 denotes 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 (not shown) and rotates integrally with the output shaft. To do. The cam 1 is fixed to the cam housing 4 by the welded portion 3, and the cam 1 rotates integrally with the cam housing 4.

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 having a suction port 12, a suction passage 13 and a discharge port 14 formed on a front surface thereof, and a communication groove 15 communicating with each of the discharge ports 14 is formed on a rear surface of the rotary valve 11. Has been formed. Further, a lid member 16 is provided in close contact with the back surface. An orifice (flow resistance generating means) 17 is formed in the discharge port 14.

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, there is a positional relationship in which the intake port 12 of the rotary valve 11 and the intake / discharge hole 10 of the rotor 5 communicate with each other, and the orifice 17, the intake port 12, the intake passage 13, and the rotor 5 are connected. Oil can be sucked into the plunger chamber 7 through the suction / discharge 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.

Reference numeral 20 denotes a bearing retainer 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 bearing retainer 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. There is. Therefore, when the direction of the differential rotation changes, the rotary valve 11 rotates with the rotor 5 until the positioning protrusion 19 of the rotary valve 11 comes into contact with the notch 18 of the cam housing 4 and then with the cam housing 4. Rotate as one. 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 is a bellows having a double structure consisting of an outer cylinder and an inner cylinder, and the bellows 23 absorbs the volume expansion of the sealed oil sealed inside the joint. The material of the bellows 23 is formed of metal such as stainless steel having excellent heat resistance and oil resistance, and the plate thickness thereof is extremely thin, about 0.1 to 0.3 mm. The bellows 23 is brazed to the end plate 24 and the brazing portion 25, and is brazed to the base member 26 and the brazing portion 27.

Reference numeral 28 denotes a retainer, the retainer 28 is crimped and fixed to the cam housing 4 by a caulking portion 29, and the cylindrical portion 30 protects the bellows 23 against external obstacles such as stone splashes, and the end face portion. Reference numeral 31 prevents excessive deformation of the bellows 23. The base member 26 is formed with communication holes 33, 34 which communicate with the communication holes 32 formed in the bearing retainer 20, and the communication holes 33, 34 communicate with the bellows chamber 35 of the bellows 23.

An oil seal 36 is provided between the mouthpiece member 26 and the input shaft 6, and an O-ring 37 is provided between the bearing retainer 20 and the cam housing 4 and the mouthpiece member 26 to prevent oil leakage. is doing. Next, the operation will be described. When the filled oil sealed inside the joint thermally expands due to the operation of the joint, the filled oil flows into the bellows chamber 35 of the bellows 23 through the communication hole 32 of the bare ring retainer 20 and the communication holes 33 and 34 of the mouthpiece member 26. To do.

In this way, the bellows 23 absorbs the volume expansion of the enclosed oil and prevents unnecessary internal pressure from being generated in the portion of the joint that constitutes the container. Since the O-ring 37 and the oil seal 36 do not move and are constant, they are less likely to be damaged and durability can be improved. In addition, the accumulator piston is not required, oil leakage due to wear is eliminated, and locking due to falling does not occur.

Further, since the return spring for the accumulator piston is not necessary, it is possible to reduce the size and weight. Furthermore, the number of parts is reduced, and the number of man-hours required for assembly and management is also reduced, and the cost can be reduced. Next, FIG. 2 is a view showing a second embodiment of the present invention.

In FIG. 2, a hydraulic chamber 42 is defined by a retainer 41 fixed to the cam housing 4 and an oil seal 36 interposed between the retainer 41 and the input shaft 6, and the hydraulic chamber 42 is formed in the bearing retainer 20. It communicates with the inside of the joint through the formed communication hole 32. A bellows 43 is housed in the hydraulic chamber 42, and both ends of the bellows 43 are brazed to the end plates 44 and 45, and further brazed to the retainer 41 by the brazing portion 46 and fixed.

Communication holes 47 and 48 are formed in the retainer 41 and the end plate 41, respectively, and the bellows chamber 49 of the bellows 43 is opened to the outside through the communication holes 47 and 48. An O-ring 50 is interposed between the cam housing 4 and the retainer 41. When the temperature of the filled oil sealed in the joint increases due to the operation of the joint and the heat expands, the filled oil enters the hydraulic chamber 42 from the inside of the joint through the communication hole 32 of the bearing retainer 20 to reach the bellows. Compress 43.

As a result, the bellows 43 absorbs the volume expansion of the press-fitted oil. Also in this embodiment, the same effect as that of the above embodiment can be obtained. Next, FIG. 3 is a view showing a third embodiment of the present invention. In FIG. 3, reference numeral 51 denotes an intake passage communicating with the intake port 12, and the intake passage 51 is formed in the rotary valve 11 so as to extend to the input shaft 6. Further, the rotary valve 11 is formed with a groove 52 communicating with the suction passage 51 on the inner periphery thereof, and the groove 52 communicates with an oil hole 53 formed in the input shaft 6.

Further, the input shaft 6 is provided with an oil reservoir chamber 54 communicating with the oil hole 53, and a hydraulic chamber 55 communicating with the oil reservoir chamber 54. A mouthpiece member 56 is positioned and installed in the hydraulic chamber 55 by a snap ring 57, and an O-ring 58 for preventing oil leakage is interposed between the mouthpiece member 56 and the input shaft 6.

A bellows 60 is brazed and fixed to the base member 56 by a brazing portion 59. An oil seal 63 is provided between the protrusion 62 of the bearing retainer 61 and the input shaft 6, and a cover 64 is provided on the outer periphery of the protrusion 62 to prevent dust and the like from entering. When the temperature of the oil filled in the joint increases due to the operation of the joint and the heat expands, the oil flows through the suction passage 51, the groove 52, the oil hole 53 and the oil sump 54 into the hydraulic chamber 55. , The bellows 60 are compressed.

As a result, the bellows 60 absorbs the volume expansion of the enclosed oil. Also in this embodiment, the same effect as that of the above embodiment can be obtained. In this embodiment, since the bellows 60 is provided in the center of the joint, centrifugal force is generated in the oil when the joint rotates at high speed, and the bellows 60 is compressed even when the bellows 60 is not due to thermal expansion of the oil. That can be alleviated.

[0031]

[Effect of device]

 As described above, according to the present invention, the volume increase due to the thermal expansion of the oil filled inside the joint is absorbed by the bellows, so the O-ring and oil seal do not move and are not easily damaged. Therefore, the durability can be improved. Further, since the accumulator piston is not necessary, it is possible to prevent the lock from being leaked due to wear and falling due to falling. Moreover, since a return spring is not required, it is possible to achieve a large size and a light weight. Furthermore, the number of parts is small, and the man-hours for assembly and management are eliminated, resulting in low cost.

[Brief description of drawings]

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

FIG. 2 is a sectional view showing a second embodiment of the present invention.

FIG. 3 is a sectional view showing a third embodiment of the present invention.

[Explanation of symbols]

 1: Cam 2: Cam surface 3: Welded part 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, 51: Suction path 14: Discharge port 15: Communication groove 16: Lid member 17: Orifice (flow resistance generating means) 18: Notch 19: Protrusion 20, 61: Bearing retainer 21: Bearing 22: Needle bearing 23, 43, 60 : Bellows 24, 44, 45: End plate 25, 27, 46, 59: Brazing part 26, 56: Base member 28: Retainer 29: Caulking part 30: Cylindrical part 31: End face part 32, 33, 34, 47, 48 : Communication hole 35, 49: Bellows chamber 36, 63: Oil seal 37, 50, 58: O-ring 41: Retainer 42, 5: hydraulic chamber 52: groove 53: oil hole 54: oil reservoir 57: snap ring 62: projection 64: Cover

Claims (4)

[Scope of utility model registration request] 1. A hydraulic pump provided between relatively rotatable input and output shafts and driven by differential rotation of the both shafts, and a flow resistance generating means provided at an outlet of the hydraulic pump. In a hydraulic power transmission joint that transmits torque according to the rotational speed difference of the shaft, the bellows that absorbs the volume expansion of the enclosed oil enclosed in the joint is fixed to the mouthpiece member that has a communication hole that communicates with the inside of the joint. A hydraulic power transmission joint characterized by. 2. A hydraulic pump provided between relatively rotatable input / output shafts and driven by differential rotation of the both shafts, and a flow resistance generating means provided at an outlet of the hydraulic pump. In a hydraulic power transmission joint that transmits torque according to the difference in shaft rotation speed, a retainer is fixed on the outside of the joint to define a hydraulic chamber that communicates with the inside of the joint, and the hydraulic chamber is compressed by volume expansion of the enclosed oil. A hydraulic power transmission joint characterized in that the bellows is fixed and stored in a retainer. 3. A hydraulic pump provided between relatively rotatable input and output shafts and driven by differential rotation of the both shafts, and a flow resistance generating means provided at an outlet of the hydraulic pump. In a hydraulic power transmission joint that transmits torque in accordance with a difference in rotational speed of a shaft, a hydraulic chamber communicating with the inside of the joint is formed in one of the input / output shafts, and a bellows that is compressed by volume expansion of enclosed oil is formed in the hydraulic chamber. A hydraulic power transmission joint, which is fixed and stored in a base member. 4. The hydraulic power transmission coupling according to claim 1, wherein the bellows is made of a metal having excellent heat resistance and oil resistance and is formed to have a predetermined thickness.