JP2591928Y2 - Hydraulic power transmission coupling - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic power transmission coupling used for distributing driving force of a vehicle.

[0002]

2. Description of the Related Art Conventional hydraulic power transmission couplings include, for example, the following (Japanese Patent Application No. 2-184737).
No., see). That is, the hydraulic power transmission coupling includes a hydraulic pump driven by a rotational speed difference between the first and second rotatable members that can rotate relative to each other, and a unit that generates a flow resistance in a discharge path of the hydraulic pump, First and second due to flow resistance
A hydraulic power transmission coupling in which transmission torque between rotary members of the hydraulic power transmission coupling is controlled, the hydraulic power transmission coupling including an accumulator piston for sealing oil inside the joint and absorbing a change in volume of the sealed oil. A plurality of springs for pressing the piston, a retainer for holding and fixing the spring are provided, and the retainer is directly fixed to the joint outer cylinder.

Further, Japanese Utility Model Application No. 2-16380 proposes the following hydraulic power transmission coupling. That is, in this hydraulic power transmission joint, the accumulator piston has a ring shape, and the outer diameter portion of the piston is mounted concentrically and axially movable with respect to the first or second rotating member, and the inner diameter of the piston is Part 2 or 1
A sealing member that extends axially to the second or first rotating member and is concentrically attached to the second or first rotating member so as to be axially movable and relatively rotatable, and that seals the outer diameter portion of the piston in the axial direction. A seal member is provided on the inner diameter portion for sealing in the axial and rotational directions with the second or first rotating member.

Japanese Patent Application No. 2-74479 discloses the following hydraulic power transmission coupling. That is, the hydraulic power transmission coupling includes an accumulator piston that absorbs a change in volume of the sealed oil sealed inside the joint,
A return spring that presses the accumulator piston, and a retainer that holds the return spring,
A communication hole communicating the room defined by the accumulator piston and the retainer and the outside of the joint is provided at a position at least outside the outer diameter of the accumulator piston of the retainer.

[0005]

However, in such a conventional hydraulic power transmission coupling, in any case, when used under severe environmental conditions for an automobile, the gear carrier of the final reduction gear is used. There is not much problem when installed inside the transfer case or inside the transfer case, but when installed between the final reduction gear and the propeller shaft or between the propeller shaft and the transfer case, the following problems occur. Occurs.

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

(4) Since the internal pressure increases due to the rotation of the joint, it is necessary to set the force of the spring to be strong, and the spring becomes large and heavy. (5) The number of parts is large, and assembling and management also require man-hours and are expensive. The present invention has been made in view of such conventional problems, and prevents the O-ring and the oil seal from being damaged, and prevents the lock and the oil leakage due to the fall of the accumulator piston, thereby reducing the size and weight. It is an object of the present invention to provide a low-cost hydraulic power transmission coupling with a reduced number of parts.

[0008]

In order to achieve the above object, the present invention is provided between input / output shafts which can rotate relative to each other.
A hydraulic power transmission coupling, comprising: a hydraulic pump driven by differential rotation of the two shafts; and a flow resistance generating means provided at an outlet of the hydraulic pump, and transmitting torque according to a rotational speed difference between the two shafts. The bellows for absorbing the volume expansion of the oil sealed in the joint is fixed to a base member having a communication hole communicating with the inside of the joint.

Further, the present invention provides a hydraulic pump provided between an input / output shaft which is rotatable relative to each other and driven by differential rotation of the two shafts, and a flow resistance generating means provided at an outlet of the hydraulic pump. A hydraulic power transmission coupling for transmitting torque in accordance with the rotational speed difference between the two shafts, wherein a hydraulic chamber communicating with the interior of the coupling by fixing a retainer outside the coupling is defined;
The bellows, which is compressed by the volume expansion of the enclosed oil, is fixedly accommodated in a retainer in a hydraulic chamber.

The present invention also provides a hydraulic pump provided between an input / output shaft which is rotatable relative to each other and driven by differential rotation of the two shafts, and a flow resistance generating means provided at an outlet of the hydraulic pump. A hydraulic power transmission joint for transmitting torque according to the rotational speed difference between the two shafts, wherein a hydraulic chamber communicating with the inside of the joint is formed on one of the input and output shafts, and the volume expansion of the sealed oil is performed in the hydraulic chamber. The bellows to be compressed is fixed and stored in a base member.

[0011]

[0012]

According to the hydraulic power transmission coupling of the present invention having the above-described structure, when the temperature of the sealed oil enclosed in the coupling rises due to the operation of the coupling and the oil expands, the thermal expansion is reduced by the bellows. Absorbs. In this case, since the O-ring and the oil seal do not move and are constant, the O-ring and the oil seal are less likely to be damaged, and the durability can be improved.

Further, an accumulator piston is not required, and oil leakage due to wear is eliminated, and lock due to falling is not generated. In addition, since a return spring for the accumulator piston is not required, the size and weight can be reduced. Furthermore, the number of parts is reduced, the man-hours for assembling and managing are not required, and the cost can be reduced.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the present invention. First,
The configuration will be described. In FIG. 1, reference numeral 1 denotes a cam having a cam surface 2 having two or more peaks on an inner surface thereof.
Is connected to an output shaft (not shown) and rotates integrally with the output shaft. Further, the cam 1 is fixed to the cam housing 4 at the welding 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 connected to the input shaft 6,
It rotates integrally with the input shaft 6. A plurality of plunger chambers 7 are formed in the rotor 5 in the axial direction.
Inside, a plurality of plungers 8 are slidably accommodated via return springs 9. Further, a plurality of suction / discharge holes 10 are formed in the rotor 5 so as to communicate with each plunger chamber 7.

Reference numeral 11 denotes a suction port 12 and a suction passage 13 on the surface.
And a rotary valve in which a discharge port 14 is formed.
Is formed with a communication groove 15 communicating with each of them. Further, a lid member 16 is provided on the back surface so as to be in close contact therewith. An orifice (flow resistance generating means) 17 is formed in the discharge port 14.

The rotary valve 11 has a positioning projection 19 which engages with a notch 18 formed on the inner periphery of the cam housing 4. The rotary valve 11 constitutes a timing member for determining the opening / closing timing of the suction / discharge hole 10, and the notch 18 and the projection 19 constitute a positioning mechanism for regulating the phase relationship between the cam 1 and the rotary valve 11.

When the plunger 8 is in the suction stroke,
There is a positional relationship between the suction port 12 of the rotary valve 11 and the suction and discharge hole 10 of the rotor 5, and the orifice 17,
Suction port 12, suction path 13, suction discharge port 1 of rotor 5
Through 0, oil can be sucked into the plunger chamber 7. When the plunger 8 is in the discharge stroke, the relationship is opposite to that of the suction stroke, and the suction and discharge holes 10 of the rotor 5 communicate with the communication groove 15 through the discharge port 14 of the rotary valve 11.

Reference numeral 20 denotes a bearing retainer which 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. Therefore, when the direction of the differential rotation changes, the rotary valve 1
1 rotates together with the rotor 5 and the rotary valve 11
Of the cam housing 4 is the notch 1
After rotating until it hits 8, it rotates integrally with the cam housing 4. Thus, the suction / discharge port 10 is forcibly opened / closed at a predetermined timing even in the normal rotation or the reverse rotation.

Reference numeral 23 denotes a bellows having a double structure consisting of an outer cylinder and an inner cylinder. The bellows 23 absorbs the volume expansion of the oil sealed in the joint. The bellows 23 is made of a metal such as stainless steel which is excellent in heat resistance, oil resistance and the like, and has a very thin plate thickness of about 0.1 to 0.3 mm. The bellows 23 is brazed at the end plate 24 and the brazing portion 25, and is brazed at the base member 26 and the brazing portion 27.

Reference numeral 28 denotes a retainer. The retainer 28 is caulked and fixed to the cam housing 4 by a caulking portion 29. The cylindrical portion 30 protects the bellows 23 against external obstacles such as stone splashes. Prevents excessive deformation of the bellows 23. The base member 26 has communication holes 33 and 3 communicating with the communication holes 32 formed in the bearing retainer 20.
The communication holes 33 and 34 communicate with the bellows chamber 35 of the bellows 23.

An oil seal 36 is interposed between the base member 26 and the input shaft 6, and an O-ring 37 is interposed between the bearing retainer 20 and the cam housing 4 and between the base member 26 to prevent oil leakage. ing. Next, the operation will be described.
When the sealed oil sealed inside the joint is thermally expanded by the operation of the joint, the sealed oil is transferred to the communication hole 3 of the bearing retainer 20.
2. It flows into the bellows chamber 35 of the bellows 23 through the communication holes 33 and 34 of the base member 26.

In this manner, the bellows 23 absorbs the volume expansion of the sealed oil and prevents the generation of unnecessary internal pressure in the portion constituting the container of the joint. O-ring 37, oil seal 3
6 does not move and is constant, so it is hard to be damaged, and the durability can be improved. Further, an accumulator piston is not required, and oil leakage due to wear is eliminated, and lock due to falling is not generated.

Also, since a return spring for the accumulator piston is not required, the size and weight can be reduced. Furthermore, the number of parts is reduced,
No man-hours are required for management, and costs 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.
The hydraulic chamber 42 communicates with the inside of the joint via the communication hole 32 formed in the bearing retainer 20. A bellows 43 is housed in the hydraulic chamber 42, and both ends of the bellows 43 are brazed to end plates 44 and 45.
Is brazed to the retainer 41 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 oil sealed inside the joint rises due to the operation of the joint and the oil expands, the sealed oil enters the hydraulic chamber 42 from the inside of the joint through the communication hole 32 of the bearing retainer 20, and enters the bellows 43. Compress.

Thus, the bellows 43 absorbs the volume expansion of the press-fitting oil. In this embodiment, the same effects as in 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 a suction passage communicating with the suction port 12, and the suction passage 51 is formed in the rotary valve 11 so as to extend to the input shaft 6.
The rotary valve 11 is provided with a groove 5 communicating with the suction passage 51.
2 is formed on the inner periphery, and the groove 52 communicates with an oil hole 53 formed in the input shaft 6.

An oil sump chamber 54 communicating with the oil hole 53 is formed on the input shaft 6, and a hydraulic chamber 55 communicating with the oil sump chamber 54 is formed. A base member 56 is provided in the hydraulic chamber 55.
Are positioned and provided by the snap ring 57,
An O-ring 58 for preventing oil leakage is interposed between the base member 56 and the input shaft 6.

A bellows 60 is fixed to the base member 56 by brazing by a brazing portion 59. An oil seal 63 is provided between the projection 62 of the bearing retainer 61 and the input shaft 6, and a cover 64 for preventing intrusion of dust and the like is provided on the outer periphery of the projection 62.
When the temperature of the encapsulated oil enclosed in the joint rises due to the operation of the joint and thermally expands, the encapsulated oil is supplied to the suction passage 51, the groove 52,
The oil flows into the hydraulic chamber 55 through the oil hole 53 and the oil sump chamber 54 to compress the bellows 60.

Thus, the bellows 60 absorbs the volume expansion of the sealed oil. In this embodiment, the same effects as in the above embodiment can be obtained. In this embodiment, since the bellows 60 is provided at the center of the joint, when the joint rotates at high speed, centrifugal force is generated in the oil, and the bellows 6
It is possible to alleviate the compression of "0" even when it is not due to thermal expansion of the oil.

[0031]

As described above, according to the present invention, the O-ring and the oil seal do not move because the bellows is used to absorb the volume increase due to the thermal expansion of the oil sealed inside the joint. , It is less likely to be damaged, and the durability can be improved. Further, since the accumulator piston is not required, it is possible to prevent oil leakage due to wear and locking due to falling down. Further, since a return spring is not required, the size and weight can be reduced. Furthermore, the number of parts is small, the number of assembling and management steps is reduced, and the cost is reduced.

[Brief description of the 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 portion 4: cam housing 5: rotor 6: input shaft 7: plunger chamber 8: plunger 9: return spring 10: suction and 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: projection 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: Cap member 28: Retainer 29: Caulking part 30: Cylindrical part 31: End face part 32, 33, 34, 47, 48 : Communication holes 35, 49: bellows chambers 36, 63: oil seals 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

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-64726 (JP, A) JP-A-3-244835 (JP, A) JP-A-4-73432 (JP, A) 15859 (JP, U) JP-A-3-107526 (JP, U) JP-A 4-32328 (JP, U) JP-A 5-71464 (JP, U) (58) Fields surveyed (Int. Cl. ⁶ , DB name) F16D 31/00-31/08

Claims (3)

(57) [Scope of request for utility model registration] 1. A hydraulic pump provided between an input / output shaft that is rotatable relative to each other and driven by differential rotation of the two 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 the rotational speed of a shaft, a bellows that absorbs the volume expansion of the sealed oil sealed inside the joint is fixed to a base member that has a communication hole communicating with the inside of the joint. A hydraulic power transmission coupling characterized by: 2. A hydraulic pump provided between an input / output shaft which is relatively rotatable and driven by a differential rotation of the two 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 outside the joint to define a hydraulic chamber that communicates with the inside of the joint, and the hydraulic chamber is compressed by the volume expansion of the enclosed oil. A hydraulic power transmission coupling characterized in that a bellows is fixed and stored in a retainer. 3. A hydraulic pump provided between an input / output shaft that is rotatable relative to each other and driven by differential rotation of the two shafts; and a flow resistance generating means provided at an outlet of the hydraulic pump. In a hydraulic power transmission coupling for transmitting torque according to a rotational speed difference between shafts, a hydraulic chamber communicating with the inside of the coupling is formed on one of the input and output shafts, and a bellows that is compressed by volume expansion of a sealed oil is formed in the hydraulic chamber. A hydraulic power transmission joint fixed to a base member and housed.