JP3401392B2 - 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 joint used for distributing a driving force of a vehicle, and more particularly to torque cutting at a predetermined vehicle speed.

[0002]

2. Description of the Related Art Conventional hydraulic power transmission joints include, for example, the following. This hydraulic power transmission joint is provided between input / output shafts that can rotate relative to each other, is connected to the one shaft, and has a cam housing formed on a cam surface having two or more ridges on the inner side surface; A rotor coupled to the shaft and rotatably housed in the cam housing and having a plurality of plunger chambers formed in the axial direction; reciprocating under the pressure of a return spring in each of the plurality of plunger chambers. Plural plungers that are movably accommodated and that are driven by the cam surface when the two shafts rotate relative to each other; suction and discharge holes formed in the rotor and communicating with the plunger chamber; and end faces of the rotor. The slide valve is rotatably slid and positioned in a predetermined relationship with the cam housing. The action of the suction valve and the discharge valve depends on the positional relationship with the suction and discharge holes. A rotary valve having a plurality of suction ports and discharge ports formed on its surface, and a flow resistance generating means for generating a flow resistance by the flow of the discharge oil by driving the plunger; depending on the rotational speed difference between the two shafts. Transmits torque.

In such a hydraulic power transmission joint,
If different diameter tires are mounted on the front and rear axles, the differential rotation speed increases as the vehicle speed increases, the torque increases, and if the front and rear vehicle differentials retain torque, the differential overheats and damage occurs. Will end up. In order to solve such a problem, it has been proposed that a spool that moves according to the vehicle speed (centrifugal force) is provided in the rotary valve to cut the torque (see FIGS. 7 to 9). ).

FIG. 7 is a partial front view of a rotary valve of a hydraulic power transmission coupling, FIG. 8 is a partial sectional view of the rotary valve for explaining an initial state, and FIG. 9 is a rotary valve for explaining an oil flow during operation. FIG. 7 to 9, 101 is a rotary valve of a hydraulic power transmission joint, and a discharge port 102 is provided on the surface of the rotary valve 101.
Is formed, and the discharge port 102 is the rotary valve 101.
To the communication groove 103 formed on the back surface of the. A suction port and a suction passage (not shown) are formed on the surface of the rotary valve 101.

A protrusion 104 is formed on the outer periphery of the rotary valve 101, and the protrusion 104 is adapted to engage with a notch formed in a cam housing (not shown).
Arrow A indicates the rotation direction of the rotary valve 101. A storage hole 105 is formed in the rotary valve 101 from the outer periphery toward the discharge port 102, and a roll pin 106 is installed at the opening of the storage hole 105. A spool valve 107 is slidably housed in the housing hole 105 in the radial direction (centrifugal direction).

The spool valve 107 includes a first valve body 10
7A, a second valve body 107B, and a shaft portion 107C that connects the first valve body 107A and the second valve body 107B, and the first valve body 107A and the second valve body 107B An inflow chamber 108 into which oil flows is formed between them. Between the second valve body 107B of the spool valve 107 and the roll pin 106, a spring 109 for urging the spool valve 107 with a spring force indicated by an arrow P is interposed. On the other hand, a centrifugal force as indicated by arrow F acts on the spool valve 107.

On the surface of the rotary valve 101, the inflow chamber 1
08, the inflow hole 110 communicating with 08 is formed, and the inflow hole 110
Is a communication passage 111 formed on the surface of the rotary valve 101.
Through the discharge port 102. Therefore, as shown in FIG. 8, the high-pressure oil in the discharge port 102 passes through the communication passage 111 and the inflow hole 110 and flows into the inflow chamber 10.
Inflow to 8.

Further, a drain hole 112 is formed on the back surface of the rotary valve 101, and the drain hole 112 has an initial state as shown in FIG.
It is closed by the second valve body 107B. As shown in FIG. 9, when the spool valve 107 moves in the centrifugal direction by centrifugal force, the drain hole 112 causes the second valve body 107 to move.
Opened by B. A pressure relief hole 113 is formed on the back surface of the rotary valve 101 below the drain hole 112, and the pressure relief hole 113 communicates with the storage hole 105.

In an initial state in which the vehicle speed is low and the centrifugal force is low, the spring force P of the spring 109 is larger than the centrifugal force F acting on the spool valve 107, as shown in FIG. Since it does not move, the drain hole 112 is closed. Therefore, the oil from the discharge port 102 is
11, it flows into the inflow chamber 108 through the inflow hole 110, but is not drained to the low pressure chamber side from the drain hole 112. In this initial situation, normal torque characteristics are obtained.

When the vehicle speed exceeds a predetermined value and the centrifugal force F exceeds a predetermined value, the centrifugal force F applied to the spool valve 107 becomes larger than the spring force P of the spring 109 as shown in FIG. The drain hole 112 is opened by moving in the direction indicated by the arrow B. Therefore, the high-pressure oil in the discharge port 102 is, as indicated by the arrow C,
It enters the inflow chamber 108 through the communication passage 111 and the inflow hole 110, and drains from the drain hole 112. In this way, torque cut is performed.

[0011]

However, in such a conventional hydraulic power transmission joint, the clearance between the spool and the housing hole is narrowed to prevent oil leakage from the high pressure chamber and to prevent torque. However, there is a problem in that the spool may malfunction due to clogging of contaminants in order to avoid the decrease in the temperature.

If the clearance between the spool and the storage hole is widened in order to avoid defective operation of the spool due to clogging of contaminants, there is a problem that the torque decreases due to oil leakage from the high pressure chamber. The present invention has been made in view of the above conventional problems, and by using a ball valve instead of a spool valve, the seal at the clearance is abolished, and malfunctions due to contamination clogging are avoided, and An object of the present invention is to provide a hydraulic power transmission joint that can prevent a decrease in torque due to leakage.

[0013]

First, the present invention is provided between input / output shafts capable of relative rotation, and is connected to one shaft,
A cam housing formed on a cam surface having two or more ridges on its inner surface; a rotor connected to the other shaft and rotatably housed in the cam housing, and a plurality of plunger chambers formed in the axial direction A plurality of plunger chambers, each of which is housed in each of a plurality of plunger chambers so as to be reciprocally movable under the pressure of a return spring and driven by a cam surface when the two shafts relatively rotate; The suction / discharge hole communicating with the plunger chamber; rotatably slidably contacting the end surface of the rotor, and positioned in a predetermined relationship with the cam housing. The suction valve and the discharge valve function according to the positional relationship with the suction / discharge hole. A rotary valve with multiple suction ports and discharge ports formed on the surface and the flow of discharge oil by driving the plunger creates flow resistance. Comprising a flow resistance generating means; Target hydraulic power transmission joint for transmitting torque corresponding to the rotational speed difference between the axes.

Regarding such a hydraulic power transmission joint, the present invention relates to a storage hole formed outside the discharge port of the rotary valve, a weight member movably stored in the storage hole by centrifugal force, and a storage hole. A drain hole communicating with the discharge port and a ball that closes the drain hole provided inside the rotation of the weight member and opens the drain hole when the weight member is moved by centrifugal force are provided.

A plurality of spring accommodating holes are formed in such a weight member, the spring is accommodated in the spring accommodating hole, the weight member is pressed by a predetermined spring force, and the spring is held by a retainer fixed to the rotary valve. did. In addition, the upper surface and the lower surface of the weight member are formed in a curved shape, and the ball housing portion for housing the ball is formed on the lower surface.

According to the hydraulic power transmission joint of the present invention having such a structure, unlike the conventional case, the spool does not seal the oil in the high pressure chamber, so that the oil leakage is prevented from being lowered and the contamination is prevented. A malfunction due to clogging can be avoided. Also, since the discharge port is sealed by the spring force via the ball and relieved with a predetermined hydraulic pressure, it can have the function of a torque limiter, and the drive system that transmits torque can be downsized according to the limit torque. it can.

Further, even if the vehicle speed is not centrifugally off, the torque can be cut when the muffled torque due to slip reaches the limit torque. Further, the torque can be limited by changing the spring force of the spring.

[0018]

FIG. 1 is a sectional view showing an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a cam having an inner surface formed with a cam surface 2 having two or more peaks. The cam 1 is connected to an output shaft (not shown) and rotates integrally with the output shaft.
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, and the rotor 5 is connected to the input shaft 6,
It rotates integrally with the input shaft 6. Plural plunger chambers 7 are formed in the rotor 5 in the axial direction.
A plurality of plungers 8 are slidably housed inside 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 indicates a suction port 12 and a suction passage 13 on the surface.
And a discharge port 14 are formed on the rear surface of the rotary valve 11.
A communication groove 15 communicating with each of the above is formed. Further, a lid member 16 is provided in close contact with the back surface to close the communication groove 15. Further, the rotary valve 11 has a positioning projection 18 that engages with a notch 17 formed on the inner circumference of the cam housing 4.

The rotary valve 11 constitutes a timing member which determines the opening / closing timing of the intake / discharge hole 10, and the notch 17 and the projection 18 constitute a positioning mechanism which regulates the phase relationship between the cam 1 and the rotary valve 11. . When the plunger 8 is in the suction process, the rotary valve 11
Of the suction port 12 of the rotor 5 and the suction / discharge hole 10 of the rotor 5 communicate with each other.
2. Through the suction passage 13 and the suction / discharge hole 10 of the rotor 5,
Oil can be sucked into the plunger chamber 7.

When the plunger 8 is in the discharge process, the relationship is the reverse of the suction process, and the suction / discharge hole 10 of the rotor 5 communicates with the communication groove 15 through the discharge port 14 of the rotary valve 11. Reference numeral 19 is a bearing retainer that rotates integrally with the cam housing 4, and the bearing 20
The input shaft 6 is supported via. A thrust needle bearing 21 is interposed between the bearing retainer 19 and the rotary valve 11, and the friction torque on the thrust needle bearing 21 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 differential rotation changes,
The rotary valve 11 revolves around with the rotor 5, rotates until the positioning protrusion 18 of the rotary valve 11 contacts the notch 17 of the cam housing 4, and then rotates together with the cam housing 4. As a result, the intake / discharge holes 10 are forcibly switched at a predetermined timing even during normal rotation or reverse rotation.

An oil seal 22 is provided between the bearing retainer 19 and the input shaft 6, and an accumulator piston 23 for absorbing thermal expansion / contraction of oil is slidably housed inside the input shaft 6. Has been done. Reference numeral 24 is a lid member that prevents muddy water from entering the O-ring sliding portion of the accumulator chamber 25. Accumulator chamber 25 is oil passage 2
6, 27 communicates with the inside of the joint. The rotary valve 11 has a high pressure chamber 2 communicating with the discharge port 14.
8 is formed, and the outlet of the high pressure chamber 28 is closed by the plug 29. In addition, 30 is an oiling hole, 31 is a needle bearing, 32 is a screw hole, 33 and 34 are O-rings, 3
Reference numerals 5 and 36 are snap rings, and 37 is a mounting hole.

FIG. 2 is a view showing a part of the rotary valve 11. In FIG. 2, 11 is a rotary valve, and a discharge port 14 is formed in the rotary valve 11. A high pressure chamber 28 communicating with the discharge port 14 through a through hole 38 is formed in the rotary valve 11, a hardened collar member 39 is housed in the high pressure chamber 28, and a plug 29 follows the collar member 39. It is screwed on.

A storage chamber 41 is formed in the collar member 39 for movably storing a ball 40 as a valve element. The storage chamber 41 communicates with the through hole 38 through the opening 42, and communicates with the communication hole 44 through the opening 43. The communication hole 44 communicates with a storage hole 46 that stores the pin member 45, and the pin member 45 is slidably stored in the storage hole 46. The pin member 45 has a small-diameter pin portion 47 and a large-diameter base end portion 48, and the position of the ball 40 is controlled by the pin member 45.

The gap between the pin portion 47 and the communication hole 44 is
The orifice 49 serves as a flow resistance generating means. Therefore, the communication hole 44 can be formed to have a large hole diameter, and the hole diameter accuracy can be made rough. When the ball 40 is held by the pin member 45, the orifice 49 is open, but when the ball 40 becomes free, the ball 40 is seated on the valve seat 50 formed in the opening 43 of the collar member 39. , Orifice 49 is closed.

The pin member 45 housed in the housing hole 46 is urged by the spring 51 to hold the ball 40, and when the hydraulic pressure in the housing chamber 41 housing the ball 40 rises above a predetermined value, the pin member 45 The member 45 is a spring 51
It moves to the right against the and contacts the pin member 52. The pin member 52 prevents the pin member 45 from moving beyond a certain distance. Reference numeral 53 is a low pressure hole communicating with the low pressure chamber side.

FIG. 3 is a sectional view of the main part. In FIG.
Reference numeral 11 denotes a rotary valve, and a discharge port 14 and a suction port 12 are alternately formed in the rotary valve 11 in the circumferential direction. The suction port 12 is communicated with a suction passage 13 formed to extend to the outer peripheral surface of the rotary valve 11.

A storage hole 61 is formed outside the discharge port 14 and on the outer circumference of the rotary valve 11. The storage hole 61 is formed as a long hole that is long in the circumferential direction, and the bottom surface is curved. A weight member 62 is housed in the housing hole 61 so as to be movable in the radial direction (centrifugal direction). The weight member 62 is curved so that its bottom surface corresponds to the bottom surface of the housing hole 61, and its upper surface is also curved corresponding to the outer peripheral surface of the rotary valve 11. The weight member 62 has flat surface portions 62A and 62B on both sides.
It has a protruding portion 62C between it and B.

Spring accommodation holes 62D and 62E are formed in the flat portions 62A and 62B, and springs 63A and 63B are accommodated in the spring accommodation holes 62D and 62E, respectively. A spring accommodating hole 62F is also formed in the center of the protrusion 62C of the weight member 62, and a spring 63C is accommodated in the spring accommodating hole 62F. These springs 63A, 63B, 63C are retainers 64
The retainer 64 is retained by the bolts 65A, 65B.
Is fixed to the rotary valve 11. Storage hole 6
Drained hole 66 is formed between the 1 and the ejection out port 14, ejection exit port 14 and the receiving hole 61 is adapted to be communicated through the drain hole 66.

A storage groove 68 for storing a part of the ball 67 is formed on the outlet side of the drain hole 66.
Receiving groove 69 for accommodating a portion of the ball 67 to rotate inside corresponding to the bottom surface of the weight member 62 corresponding to 8 is formed. The ball 67 is stored in the storage grooves 68, 69,
The ball 67 normally closes the drain hole 66. A predetermined gap 70 is formed between the weight member 62 and the storage hole 61.

The springs 63A, 63B, 63C press the weight member 62 with a predetermined spring force, and are stored in a storage groove 69 on the lower surface side of the weight member 62 and a storage groove 68 formed on the outlet side of the drain hole 66. The ball 67 closes the drain hole 66 by the spring force of the springs 63A, 63B, 63C, reaches a predetermined vehicle speed, and the weight member 62 moves in the centrifugal direction by centrifugal force.
Opens the drain hole 66.

Next, the operation will be described. In FIG. 1, 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. In addition,
At this time, the plunger 8 is pressed against the cam surface 2 by the return spring 9. Next, when a rotation difference occurs between the cam 1 and the rotor 5, the plunger 8 in the discharge stroke is pushed axially by the cam surface 2 of the cam 1.

At this time, the suction / discharge hole 10 is formed in the discharge port 14
Plunger 8 is connected to plunger room 7
Oil is pushed out 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 passes from the suction passage 13 through the orifice to the suction port 12
Is supplied to. At this time, the hydraulic pressure in the discharge port 14 and the plunger chamber 7 increases due to the resistance of the orifice, and a reaction force is generated in the plunger 8.

A torque is generated by rotating the cam 1 against the plunger reaction force, and the cam 1 and the rotor 5 are rotated.
Torque is transmitted between and. Since the discharge port 14 is communicated with the communication groove 15, the hydraulic pressures of all the plunger chambers 7 in the discharge stroke are equal. Further, when the cam 1 rotates, the suction stroke occurs, and the suction / discharge hole 10 communicates with the suction port 12. Therefore, the oil in the suction passage 13 passes through the suction port 12 and the suction / discharge hole 10 and the plunger chamber 7
And the plunger 8 returns along the cam surface 2 of the cam 1.

Next, as shown in FIG. 4, when the vehicle speed V becomes equal to or higher than a constant value V1, the centrifugal force F also exceeds a predetermined value F1, so that even if the transmitted torque ΔT is zero, it is indicated by D. Torque cut is performed. That is, when the vehicle speed V becomes equal to or higher than the constant value V1, the centrifugal force F acting on the weight member 62 is generated by the springs 63A, 63B, regardless of the hydraulic pressure value.
Since the spring force of 63C is exceeded, the weight member 62 moves in the centrifugal direction against the springs 63A, 63B, 63C.

Therefore, the ball 67 held by the weight member 62 floats from the storage groove 68 of the rotary valve 11 and opens the drain hole 66. The high-pressure oil from the discharge port 12 drains to the low-pressure chamber side through the drain hole 66, the storage groove 68, and the gap 70. The torque characteristic after such torque cut is shown in FIG.
Although the torque T increases according to m, the magnitude thereof can be freely set by the drain area, and the transmitted torque T can be reduced.

Unlike the conventional example, since the oil in the high pressure chamber is not sealed by the spool but is sealed by the ball 67, there is no decrease in torque due to oil leakage, and no malfunction due to contamination clogging. In FIG. 4, when the vehicle speed V does not reach the constant value V1, the centrifugal force F
Also does not reach the predetermined value F1, the torque cut D is not performed. That is, when the vehicle speed V does not reach the constant value V1, the centrifugal force F acting on the weight member 62 is smaller than the spring force of the springs 63A, 63B, 63C, and therefore the weight member 62 does not move. Therefore, the ball 6
7 keeps the drain hole 66 closed. FIG. 6 shows torque characteristics when such torque cut is not performed.

That is, when the rotational speed difference rpm does not reach the predetermined value, the oil pressure is small and the force of pushing the pin member 45 by the spring 51 is larger than the force of pushing the pin member 45 by the oil pressure in the storage chamber 41. The ball 40 is held by 45, and the oil passes through the orifice 49.
Therefore, the torque characteristic at this time becomes a normal torque characteristic as shown by a in FIG.

Next, when the rotation difference rpm exceeds a predetermined value,
The hydraulic pressure in the storage chamber 41 rises, and the force pushing the pin member 45 by the hydraulic pressure in the storage chamber 41 causes the pin member 4 by the spring 51.
5, the pin member 45 moves to the right, the spring 51 contracts, the ball 40 becomes free, the ball 40 is seated on the valve seat 50, and the orifice 4
9 is closed. The torque characteristic at this time becomes a lock characteristic as shown in FIG.

As shown in FIG. 4, when the centrifugal force F due to the vehicle speed V increases, the load holding the ball 67 decreases, and the limit torque ΔT also decreases accordingly. For example, when the vehicle speed V reaches V2, the centrifugal force F is F2, and the limit torque ΔT also drops to ΔT1. At this time, the hydraulic pressure becomes a predetermined value, and the limit torque ΔT becomes ΔT.
When it exceeds 1, torque cut D is performed. The torque at this time is a constant torque as shown by C in FIG. 6, for example.

As described above, the function of the torque limiter can be provided, and the drive system (differential, drive shaft, etc.) for transmitting the torque through the joint can be downsized in accordance with the limiter torque. Further, as described above, the torque can be cut not only when the hydraulic pressure exceeds a predetermined value, but also when the muffled torque generated due to a slip or the like reaches the limit torque ΔT even at a vehicle speed V at which centrifugal separation is not achieved. Further, the springs 63A, 63B, 6
By changing the spring force of 3C, it is possible to have a function of a torque limiter.

As described above, in this embodiment, unlike the prior art, since the spool does not seal the high pressure chamber, the torque for leaking oil does not decrease, and malfunctions due to clogging of contamination are avoided. You can Also,
Since the high pressure chamber is sealed via the ball 67 by the spring force of the springs 63A, 63B, 63C, the torque can be cut with a predetermined hydraulic pressure, the function of a torque limiter can be provided, and the drive system can be adjusted according to the limiter torque. Can be miniaturized. Also, the spring 63
The function of the torque limiter can be obtained by changing the spring force of A, 63B, 63C.

[0045]

As described above, according to the present invention, it is possible to prevent a decrease in torque due to an oil leak, and it is possible to avoid a malfunction due to contamination clogging. Further, since it has a torque limiter function, the drive system can be downsized in accordance with the limiter torque. Further, the torque limiter characteristic can be obtained by changing the spring force of the spring.

[Brief description of drawings]

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

FIG. 2 is a partial sectional view of a rotary valve.

FIG. 3 is a sectional view of a main part of a rotary valve

FIG. 4 is a graph showing the relationship between vehicle speed, centrifugal force, and limit torque.

FIG. 5 is a graph showing torque characteristics after torque cut.

FIG. 6 is a graph showing torque characteristics when torque is not cut.

FIG. 7 is a diagram showing a conventional example.

FIG. 8 is an explanatory diagram showing a conventional initial state.

FIG. 9 is an explanatory view showing a conventional operation time.

[Explanation of symbols]

1: cam 2: Cam surface 3: Weld 4: Cam housing 5: rotor 6: Input shaft 7: Plunger room 8: Plunger 9: Return spring 10: Intake and discharge holes 11: Rotary valve 12: Inhalation port 13: Inhalation route 14: Discharge port 15: Communication groove 16: Lid member 17: Notch 18: Protrusion 19: Bearing retainer 20: Bearing 21: Thrust needle bearing 22: Oil seal 23: Accumulator piston 24: Lid member 25: Accumulator room 26, 27: Oil passage 28: High pressure chamber 29: Plug 30: Oiling hole 31: Needle bearing 32: Screw hole 33, 34: O-ring 35, 36: Snap ring 37: Mounting hole 38: Through hole 39: Color member 40: Ball (valve body) 41: Storage room 42, 43: openings 44: Communication hole 45: Pin member 46: Storage hole 47: Pin part 48: Base end 49: Orifice 50: valve seat 51: Spring 52: Pin member 53: Low pressure hole 61: Storage hole 62: Weight member 62A, 62B: Flat part 62C: protrusion 62D, 62E, 62F: Spring storage holes 63A, 63B, 63C: Spring 64: Retainer 65A, 65B: Bolt 66: Drain hole 67: Ball 68, 69: Storage groove 70: Gap

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiroyuki Nakano Inventor Hiroyuki Nakano 2418 Washizu, Kosai City, Shizuoka Fuji Univance Co., Ltd. (56) References JP-A-2-275124 (JP, A) JP-A-8-193628 (JP) , A) Actual Kaihei 7-10567 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16D 25/0638 F16D 31/00-31/02 F16D 35/00

Claims (2)

(57) [Claims] 1. A cam housing provided between relatively rotatable input / output shafts, connected to said one shaft, and formed on a cam surface having two or more ridges on its inner side surface; and connected to said other shaft. A rotor having a plurality of plunger chambers axially formed therein and rotatably housed in the cam housing; and a plurality of plunger chambers each of which is reciprocally movable under the pressure of a return spring. A plurality of plungers that are housed and driven by the cam surface when the two shafts rotate relative to each other; suction and discharge holes that are formed in the rotor and that communicate with the plunger chamber; A plurality of slide valves that are in sliding contact with each other and are positioned in a predetermined relationship with the cam housing and act as suction valves and discharge valves depending on the positional relationship with the suction and discharge holes. A rotary valve having a suction port and a discharge port formed on its surface, and a flow resistance generating means for generating a flow resistance by the flow of the discharge oil by driving the plunger; transmitting torque according to a difference in rotational speed between the two shafts. In the hydraulic power transmission joint, a storage hole formed outside the discharge port of the rotary valve, a weight member movably stored in the storage hole by centrifugal force, the storage hole and the discharge port. It includes a drain hole that communicates, and a ball to open the drain hole when the weight member by centrifugal force to close the drain hole provided on the rotating inner side of the weight member is moved to a plurality of spring housed in said weight member Forming a hole,
Store the spring in the spring storage hole and
Press the weight member with a ring force to push the spring.
Be held by a retainer fixed to the rotary valve
Hydraulic power transmission joint according to claim. 2. The hydraulic power transmission joint according to claim 1, wherein the upper surface and the lower surface of the weight member are curved, and a ball storage portion for storing the ball is formed on the lower surface. Power transmission joint.