JPH08219181A - Viscous fluid coupling - Google Patents

Abstract

PURPOSE: To provide a viscous fluid coupling having the small power consumption, able to perform the suitable control corresponding to the vehicle traveling condition having the wide range, and to be suitably used for driving of auxiliary machines of an automobile engine by eliminating inconvenience of shock in transmitting of driving force. CONSTITUTION: A viscous fluid coupling is provided with a first rotating member 10 provided with a reservoir chamber 11 for storing viscous fluid L and a driving force transmitting chamber 17 in which a driving force transmitting part 16 is provided, and to which the viscous fluid is to be supplied from the reservoir chamber, a second rotating member 20 provided with a rotary shaft 22 arranged on the same axis as the rotational center of the first rotating member and a driving force transmitting disc 21 rotatably arranged in the driving force transmitting chamber 17, and a valve device 30 for controlling the flow of the viscous fluid from the reservoir chamber to the driving force transmitting chamber. The valve device 30 is provided with a valve member 31 arranged in the reservoir chamber 11 of the first rotating member 10, and a valve driving means 32 for opening and closing the valve member 31 arranged on the axis on the rotational center of the first rotating member 10 and the second rotating member 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a viscous fluid coupling suitable for use in an accessory drive unit for transmitting engine driving force to an accessory for an automobile engine.

[0002]

2. Description of the Related Art Various auxiliary machines (cooler compressor, cooling fan, etc.) are attached to an engine of an automobile, and these auxiliary machines operate by utilizing the driving force of the engine. A clutch joint that controls on / off of the transmission of the engine driving force is arranged in each of these auxiliary machines, and the engine driving force is transmitted to the auxiliary machine through this clutch joint.

For example, in the case of a cooler compressor, a magnet clutch is generally used as a clutch joint. This magnet clutch connects and separates by a magnetic force a rotor that is rotating via a V-belt that is wound around the crankshaft pulley of the engine and an armature plate that is connected to the drive shaft of the cooler compressor. is there. In other words, by connecting this magnetic clutch, the driving force of the engine is transmitted to the drive shaft of the cooler compressor, and the cooler compressor operates.

On the other hand, the radiator cooling fan is for blowing air to the radiator when the temperature of the cooling water of the engine rises to improve ventilation of the radiator core portion and to promote heat exchange of the radiator. is there. Cooling fan
The cooling fan is attached to the fan clutch, and the driving force of the engine is transmitted by the fan clutch to rotationally drive the cooling fan. As the fan clutch, a viscous fluid type fan clutch that appropriately rotates the cooling fan is used in order to reduce the horsepower loss and the rotation noise when the cooling fan is unnecessary such as when traveling at high speed. . The viscous fluid type fan clutch is installed between the pulley around which the fan belt is wound and the cooling fan, and controls the flow of the viscous fluid (silicon oil) inside by bimetal that deforms according to the passing air temperature of the radiator. However, the rotation speed of the cooling fan is reduced when it is not necessary by making a difference in the rotation speed of the pulley and the cooling fan.

[0005]

By the way, when the cooler is turned on, the driving force of the engine is transmitted to the cooler compressor by the magnetic clutch, the compressor starts operating, and the refrigerant is compressed. At this time, since the driving force of the engine is instantaneously transmitted to the cooler compressor by the magnet clutch, a large impact is applied to the cooler compressor and an excessive load is also instantaneously applied to the V belt for driving the rotor. Therefore, in the cooler compressor, a failure is likely to occur due to a malfunction of impact, and in the V belt,
Slip, wear, and breakage easily occur and the service life is shortened. Further, if the driving force of the engine is instantaneously transmitted to the cooler compressor having high compression resistance, a large load is also applied to the engine side, so that the engine speed decreases and the engine speed fluctuates. In particular, if the cooler is turned on when the vehicle is accelerating or running at low speed, acceleration will slow down or the compressor will be directly connected to the engine, which will cause a large difference between the compressor speed and the engine speed. Therefore, uneven rotation of the engine may occur, and smooth running may not be possible. Further, the magnet clutch transmits a large driving force of the engine to an auxiliary machine (cooler compressor), and a strong magnetic force corresponding to it is required. Therefore, when the cooler is used, a large amount of current has to flow through the electromagnetic coil, resulting in an increase in power consumption.

On the other hand, the viscous fluid type fan clutch used for the cooling fan controls the viscous fluid which is responsible for the transmission of the driving force by a bimetal. That is, the valve in the fan clutch is opened / closed by the deformation of the bimetal, and the amount of viscous fluid flowing to the driving force transmission portion is controlled to control the rotation speed of the cooling fan. However, in reality, the relationship between the temperature of the cooling water and the temperature of the air passing through the radiator is not uniform depending on the driving conditions of the vehicle, and the cooling fan may not operate when necessary, or vice versa. That is, since the bimetal deforms only in accordance with the passing air temperature of the radiator, it is difficult to perform the optimum control corresponding to a wide range of vehicle traveling conditions.

Therefore, the present invention solves the above-mentioned problems in the auxiliary equipment of the automobile engine, eliminates the problem of impact at the time of transmitting the driving force, consumes less power, and enables optimum control corresponding to a wide range of vehicle traveling conditions. Another object of the present invention is to provide a viscous fluid coupling that is suitable for driving an auxiliary machine of an automobile engine.

[0008]

In order to achieve the above object, in the present invention, a reservoir chamber for storing a viscous fluid and a driving force transmitting portion are provided inside, and the viscous fluid is supplied from the reservoir chamber. A first rotating member having a driving force transmitting chamber, a rotating shaft disposed coaxially with a rotation center of the first rotating member, and coaxially fixed to the rotating shaft so as to be rotatable in the driving force transmitting chamber. In a viscous fluid coupling provided with a second rotating member having a driving force transmission disk disposed therein, and a valve device for controlling the flow of the viscous fluid from the reservoir chamber to the driving force transmission chamber, the valve device includes: A valve member arranged in the reservoir chamber of the first rotating member, and valve driving means for opening and closing the valve member arranged on the axis of the rotation center of the first rotating member and the second rotating member. Is equipped with Viscous fluid coupling is provided.

The valve driving means has a valve rod having one end connected to the valve member and the other end projecting outward from the rotation center of the first rotating member, and the other end of the valve rod. It is preferable to have a configuration including a magnetic attraction piece provided and an electromagnet that is disposed separately from the attraction piece so as to face the attraction piece and be separated therefrom. Further, a V-shaped groove around which a V-belt for transmitting the driving force of the engine is wound is formed on the periphery of the first rotating member, and the rotating shaft is connected to the driving shaft of the cooler compressor. preferable.

Further, it is preferable that a cooling fan is arranged around the periphery of the first rotating member, and a crankshaft pulley is coaxially fixed to the rotating shaft. At this time, it is more preferable that a radiator is arranged on the facing surface of the cooling fan, and the electromagnet is arranged on the radiator.

[0011]

In the viscous fluid coupling according to the present invention, the driving force of the engine is transmitted to the auxiliary machine via the viscous fluid, so that the change in the driving force transmitted by the clutch at the time of switching between on and off is small. The change in rotation of the auxiliary machine becomes gentle. Further, since the electromagnet disposed coaxially with the rotation shaft is used as the valve drive means, the drive of the auxiliary machine can be electrically controlled.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG. The viscous fluid coupling 1 according to the present invention can be applied to a cooler compressor. Viscous fluid coupling 1
Is a driving-side constituent element, and is a driven-side constituent element that is connected to the drive shaft of the cooler compressor 90 and the first rotating member 10 to which the driving force of the engine is transmitted via the V-belt 80. The second rotating member 20 and the first rotating member 1
0, and a valve device 30 for controlling the flow of the viscous fluid L in the reservoir chamber 11.

The reservoir chamber 11 of the viscous fluid coupling 1 is filled with a predetermined amount of viscous fluid (for example, silicon oil) L. The first rotating member 10 has a V-shaped groove portion 12 at the peripheral portion and a cylindrical hub 13 at the central portion, and has a disc-shaped clutch casing 10A as a whole and a disc-shaped clutch as a whole, and the viscous fluid L is at the central portion. And a clutch cover 10B fixed to the end surface of the clutch casing 10A on the side opposite to the cooler compressor.

In the viscous fluid coupling 1 of this embodiment,
The cooler compressor side (arrow A direction) is the back side and the opposite side (arrow B direction) is the front side. The clutch casing 10 </ b> A has a ring-shaped portion 14 on the front surface of the V groove portion 12 that is higher than the front surface of the V groove portion 12, and a front surface-side surface 1 between the V groove portion 12 and the hub 13.
6a, a plurality of ring portions 1 formed concentrically at predetermined intervals
And a driving force transmission unit 16 having 6b.

Here, the ring-shaped portion 14 is formed with a driving force transmission chamber side circulation passageway 19a having one end facing a driving force transmission chamber 17 described later and the other end opening to the end face 14a. In addition, a ball bearing 40 that rotatably supports a rotating shaft 22 described later is disposed on the inner peripheral surface 13a of the hub 13 so as to be fitted therein. Clutch cover 10B
Is provided with a cup-shaped bulging portion 11a that bulges toward the front side in the central portion, and a flange portion 18 that bulges radially outward from the peripheral edge of the opening end 11b of the bulging portion 11a. .

Here, one end of the flange portion 18 opens at the end surface 18a at a position facing the driving force transmission chamber side circulation passage 19a and communicates therewith, and the other end faces a reservoir chamber 11 described later. A reservoir chamber side circulation passage 19b is formed. A flat plate 15 is fixed along the inner peripheral edge of the opening end 11b of the bulging portion 11a to partition the bulging portion 11a and a driving force transmission chamber 17 described later. 11 are divided. Here, the flat plate 15 is a donut-shaped plate having a center hole 15b, and a circulation hole 15a is formed near the peripheral edge portion fixed to the bulging portion 11a.

The clutch casing 10A and the clutch cover 10B as described above are composed of the end surface 14 of the ring-shaped portion 14.
a and the end surface 18a of the flange portion 18 are butted against each other and are fixed in a liquid-tight manner. In this way, the clutch casing 1
The driving force transmission chamber 17 is formed by abutting 0A and the clutch cover 10B. Further, since the driving force transmission chamber side circulation passage 19a and the reservoir chamber side circulation passage 19b are communicated with each other, the driving force transmission chamber 17 and the reservoir chamber 11 are connected.
A circulation passageway 19 is formed to connect with. In the circulation passage 19, the viscous fluid L is constantly generated by the pressure generated by the viscous fluid L colliding with the viscous fluid blocking projection provided on the clutch cover 10B (not shown).
It is designed to flow only from 7 toward the reservoir chamber 11.

Since the first rotating member is normally driven to rotate, the viscous fluid L is pressed against the inner wall of the reservoir chamber 11 in the radial direction by centrifugal force. Therefore, during rotation, the viscous fluid L gets over the flat plate 15 and the driving force transmission chamber 17
Center hole 1 from the peripheral edge of the flat plate 15 so as not to leak to the side.
The distance to the edge of 5b is set longer than the height h of the liquid surface of the viscous fluid L pressed against the inner wall. Further, the amount of the viscous fluid L is preferably adjusted to a predetermined amount so as not to exceed the central hole 15b of the flat plate 15 during rotation.

The second rotating member 20 has a driving force transmitting disk 21.
And a rotary shaft 22 to which the driving force transmission disk 21 is attached. Here, the driving force transmitting disk 21 has a plurality of concentric ring portions 23a formed on the surface facing the driving force transmitting portion 16 of the clutch casing 10A so as to alternately engage with the ring portions 16b. The force transmission portion 23 is formed. That is, the ring portion 23a of the driving force transmission disk 21 is arranged so as to be inserted between the ring portions 16b of the clutch casing 10A at a predetermined interval. In addition, the driving force transmitting disk 21 is so arranged that the viscous fluid L spreads over the front surface and the back surface of the driving force transmitting disk 21.
Through hole 21 at a position between the center of 1 and the driving force transmission portion 23.
a is provided.

Next, the rotary shaft 22 is connected to a drive shaft (not shown) of the cooler compressor 90, a small diameter portion 22b formed at the tip of the connection portion 22a, and a tip of the small diameter portion 22b. It has the formed screw part 22c. In the rotary shaft 22, the connecting portion 22a may be integrally formed with the drive shaft of the cooler compressor. The rotating shaft 22 is rotatably supported by the ball bearing 40 having the small diameter portion 22b fitted therein. At this time, the rotary shaft 22 also relatively rotatably supports the clutch casing 10A via the ball bearing 40. Further, the driving force transmission disk 21 is attached to the screw portion 22c.
Is fitted so as to pass through the central through hole 21b. Then, the driving force transmission disk 21 and the rotary shaft 2
2 are fastened together by a nut 24. At this time,
The tip of the screw portion 22c projects from the center hole 15b of the flat plate 15 toward the reservoir chamber 11 side.

From the above structure, the first rotating member 10
The second rotating member 20 and the second rotating member 20 are rotatable relative to each other. The valve device 30 includes a flexible valve member 31 arranged in the reservoir chamber 11, a first rotating member 10 and a second rotating member 10.
The valve member 31 is arranged on the axis of the rotary shaft of the rotary member 20.
And a valve driving mechanism (valve driving means) 32 for driving the opening and closing.

For the valve member 31, for example, a leaf spring is used, one end of which is fixed to a part of the inner wall of the reservoir chamber 11 and the other end of which is arranged so as to close the flow hole 15a.
The valve member 31 is connected to a valve rod 32a, which will be described later, at a predetermined position substantially in the center thereof. The valve drive mechanism 32 is inserted into an insertion hole 11c formed at the center of the clutch cover 10B, and one end of the valve drive mechanism 32 is inside the reservoir chamber.
1 and the other end of the clutch cover 10B projecting outward from the front side of the clutch cover 10B, and the clutch cover 10B.
And a suction piece 32b made of a magnetic disk fixed to the tip of a valve rod 32a protruding outward from the front side of the
And an electromagnet 32c arranged at a position opposed to.

Here, the valve chamber 32a has a reservoir chamber 11
On the side, the spring 33 is externally fitted, and the valve member 31 is urged by the spring 33 in a direction to always close the flow hole 15a. Further, the suction piece 32b may be a magnetic disk fixed to the tip of the valve rod 32a as described above.
In addition to this, a magnetized tip of the valve rod 32a and the valve rod 3
The tip portion of 2a is processed into, for example, a disk shape, and the valve rod 32a
The suction piece 32b and the suction piece 32b may be formed as an integral member, and the tip portion thereof may be magnetized.

The electromagnet 32c is attached to the tip of an arm 34 extending from the body 91 of the cooler compressor. The electromagnet 32c is connected to a control circuit (not shown) via the harness 35. At this time, the distance between the electromagnet 32c and the suction piece 32b is set to an appropriate distance so that the magnetic force of the electromagnet 32c reaches the suction piece 32b and does not hinder the opening and closing of the valve member 31.

The connecting portion and the insertion hole of each member of the viscous fluid coupling 1 are provided with sealing (not shown). In the viscous fluid coupling 1, first, the driving force of the engine is transmitted to the first rotating member 10 via the V belt 80, and
The rotary member 10 is rotationally driven. Here, when the flow hole 15 a is blocked by the valve member 31 and the viscous fluid L is not supplied to the driving force transmission chamber 17, the second rotating member 20.
Is in a stopped state due to the compression resistance of the cooler compressor, and only the first rotating member 10 rotates.

Next, when the cooler is turned on, the electromagnet 32c is activated by a signal from a control circuit (not shown), and the suction piece 32b is attracted to the electromagnet 32c side.
The valve member 31 connected to the suction piece 32b is driven to the position shown by the phantom line, and the circulation hole 15a opens. Then, the viscous fluid L flows out from the circulation hole 15a and spreads throughout the driving force transmission chamber 17. At this time, the viscous fluid L is
Reservoir chamber 11 and driving force transmission chamber 1 via circulation passage 19
Cycle between 7 and. In the driving force transmission chamber 17, the viscous fluid L is the driving force transmission portion 16 of the clutch casing 10A.
And the drive force transmitting portion 23 of the drive force transmitting disk 21. The driving force is transmitted between the first rotating member 10 and the second rotating member 20 by viscous resistance of the viscous fluid L. Therefore, the driving force of the engine is transmitted to the cooler compressor via the rotary shaft 22, and the drive shaft of the cooler compressor is rotated, so that the cooler operates.

Then, when the cooler is turned off, the current to the electromagnet 32c is cut off, the supply of magnetic force is stopped, and the attraction piece 32b returns to its original position by the biasing force of the spring 33. Along with that, the valve member 31 also returns to the original position, the circulation hole 15a is closed, and the supply of the viscous fluid L to the driving force transmission chamber 17 is stopped. Then, the viscous fluid L becomes
It returns to the reservoir chamber 11 through the circulation passage 19 and the amount of the viscous fluid L in the driving force transmission chamber 17 decreases. Therefore, the viscous resistance of the driving force transmitting portion 16 of the clutch casing 10A and the driving force transmitting portion 23 of the driving force transmitting disk 21 becomes low. Therefore, the driving force of the engine is not transmitted to the cooler compressor, and the cooler compressor stops.

As described above, in the viscous fluid coupling according to the present invention, the driving force is transmitted by the viscous resistance of the viscous fluid, so that the transmission of the engine driving force to the auxiliary machine and the disconnection thereof are performed gently. For this reason, it is possible to prevent the auxiliary equipment such as the cooler compressor and the V-belt from being impacted, and also to prevent the engine from being suddenly loaded.

Next, a second embodiment of the present invention will be described with reference to FIGS. The viscous fluid coupling 2 in the second embodiment can be applied to drive a cooling fan. The viscous fluid coupling 2 is a component on the driven side, and a first rotating member 210 to which the cooling fan 3 is attached, and a second rotating member that is a component on the driving side and is coaxially fixed to the crankshaft pulley 4 of the engine. 220 and the first rotating member 21
No. 0 valve device for controlling the flow of the viscous fluid L in the reservoir chamber. That is, the viscous fluid coupling 2 is the viscous fluid coupling 1 in the first embodiment in which the driving side and the driven side are reversed, and the cooling fan 3 is attached to the peripheral edge of the first rotating member 210. The viscous fluid coupling 1 of the first embodiment except that the crankshaft pulley 4 is coaxially fixed to the rotary shaft 222 of the second rotary member 220 and the electromagnet 232c of the valve drive mechanism 232 is disposed in the radiator 70. It has substantially the same structure as. Therefore,
The internal configuration of the first and second rotating members 210 and 220 is
Since it can be easily inferred from the first embodiment, the description thereof will be omitted.

As shown in FIG. 2, the viscous fluid coupling 2 is arranged behind the radiator 70, and the radiator 70
A cross stay 71 for reinforcement and a fan shroud 72 that forms a duct between the radiator 70 and the cooling fan 3 to increase the fan air volume are attached to the. In this embodiment, the electromagnet 232c is arranged at the center of the cross stay 71 (existing structural member) of the radiator 70 so as to be located in front of the suction piece 232b of the viscous fluid coupling 2 (see FIG. 3). ). Also, the electromagnet 232c
Are connected to a control circuit (not shown) via a harness 235.

The viscous fluid coupling 2 rotates the second rotating member 220 (engine driving force) rotating through the crankshaft pulley 4 to rotate the second rotating member 220 to the first position where the cooling fan 3 is arranged.
The amount of airflow by the cooling fan 3 is changed by transmitting or disconnecting the rotary member 210 to control the ability of the radiator to assist heat exchange. That is, the amount of viscous fluid is electrically controlled by the valve device to change the amount of transmission of the engine driving force and control the rotational speed of the cooling fan 3.

More specifically, when the flow hole is closed by the valve member and the viscous fluid L is not supplied to the driving force transmission chamber, the viscous resistance of the small amount of the viscous fluid remaining in the driving force transmission chamber causes As the second rotating member 210 rotates, the first rotating member 210 also rotates. However, the transmission amount of the driving force of the engine to the first rotating member 210 is small, and the rotation speed of the first rotating member 210 and the second rotating member 220 are small.
There is a big difference with the rotation speed of. That is, in this case, the cooling fan 3 is driven at a low rotation speed, and the ability to assist the heat exchange of the radiator 70 is low.

Then, the control circuit controls the electromagnet 232c.
Is operated, the valve member is driven and the viscous fluid L is supplied to the driving force transmission chamber. Then, the viscous resistance of the viscous fluid L connects the first rotating member 210 and the second rotating member 220, and the amount of transmission of the engine driving force to the first rotating member 210 is increased. Therefore, the first rotating member 210
However, the second rotation member 220 rotates at a rotation speed close to that of the second rotation member 220. Along with this, the air volume by the cooling fan 3 increases, so that the ventilation of the core portion of the radiator 70 is improved and heat exchange is promoted.

Next, when the current to the electromagnet 232c is cut off and the supply of the magnetic force is stopped, the flow hole is closed and the supply of the viscous fluid L to the driving force transmission chamber is stopped. Then, the amount of the viscous fluid L in the driving force transmission chamber 17 decreases, so the viscous resistance decreases, and the amount of engine driving force transmitted to the first rotating member 210 decreases. Therefore, the cooling fan 3 has a reduced rotation speed and a reduced ability to assist heat exchange.

As described above, in the viscous fluid coupling according to the present invention, the control circuit controls the on / off of the electromagnet to electrically transmit and disconnect the driving force. In particular, engine cooling water temperature, engine speed, accelerator opening, vehicle speed, acceleration,
By monitoring the state of deceleration and the like and feeding it back to the control circuit, it is possible to finely control the drive state of the auxiliary machine. For example, when the engine driving force is suddenly required, such as during sudden acceleration to avoid danger, the transmission of the driving force to the cooler compressor or cooling fan is temporarily stopped to reduce the total driving force of the engine. Control such as allocating to acceleration can be performed.

[0036]

According to the viscous fluid coupling of the first aspect of the present invention, since the driving force of the engine is transmitted by viscous resistance of the viscous fluid, the transmission and disconnection of the engine driving force to the auxiliary machine is gentle. The problem of shock that occurred when the auxiliary machine was turned on and off was solved.

In the viscous fluid coupling according to the second aspect, the valve member is driven by the electromagnet to control the viscous fluid, and the driving force of the engine is transmitted by viscous resistance of the viscous fluid. It is possible to eliminate the problem of impact that has occurred when the power is off and to electrically control the drive of the auxiliary machinery. In other words, the viscous fluid coupling can suppress the impact applied to the auxiliary machine and the engine, can drive the auxiliary machine in a wide range of traveling conditions of the automobile, and can appropriately drive the auxiliary machine.

Since the viscous fluid coupling of the third aspect can be used to drive the cooler compressor, it is possible to suppress the impact on the cooler compressor and the V belt. In addition, this viscous fluid coupling does not require a large electromagnet and can have a simpler structure than the conventional magnet clutch. Furthermore, the electromagnet of the valve drive mechanism that operates this viscous fluid coupling can be driven with less electric power than the electromagnet of the conventional magnet clutch, which also contributes to reduction of power consumption. Therefore, the capacity of the alternator can be reduced.

Since the viscous fluid coupling according to the fourth aspect can be used for driving the cooling fan, it is possible to perform fine electric control as compared with the cooling fan clutch using the conventional bimetal. In the viscous fluid coupling of the fifth aspect, since the valve drive mechanism is attached to the existing structural member, that is, the cross stay of the radiator, it is not necessary to newly install a valve drive mechanism attachment jig or the like. Therefore, the number of parts can be reduced, which contributes to weight reduction of the vehicle.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of a viscous fluid coupling of a first embodiment according to the present invention.

FIG. 2 is a schematic configuration side view when a viscous fluid coupling according to a second embodiment of the present invention is used to drive a cooling fan.

FIG. 3 is the radiator 7 of FIG. 2 showing the installation position of the electromagnet.
It is the front view which saw 0 from the cooling fan side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Viscous fluid coupling (of 1st Example) 2 Viscous fluid coupling (of 2nd Example) 3 Cooling fan 10 1st rotating member 11 Reservoir chamber 15a Circulation hole 16 Driving force transmitting part 17 Driving force transmitting chamber 20 20th 2 rotary member 21 drive force transmission disk 22 rotary shaft 30 valve device 31 valve member 32 valve drive mechanism (valve driving means) 70 radiator 210 first rotary member 220 second rotary member 222 rotary shaft 232c electromagnet L viscous fluid

Claims (5)

[Claims] 1. A first rotating member having a reservoir chamber for storing a viscous fluid, a driving force transmitting portion provided therein, and a driving force transmitting chamber to which the viscous fluid is supplied from the reservoir chamber; A second rotating member having a rotating shaft arranged coaxially with the rotation center of the rotating member, and a driving force transmitting disk fixed coaxially to the rotating shaft and rotatably arranged in the driving force transmitting chamber; In a viscous fluid coupling provided with a valve device that controls the flow of a viscous fluid from the reservoir chamber to the driving force transmission chamber, the valve device is a valve member disposed in the reservoir chamber of the first rotating member. And a valve drive means for opening and closing the valve member arranged on the axis of the rotation center of the first rotating member and the second rotating member. 2. The valve driving means includes a valve rod, one end of which is connected to the valve member and the other end of which protrudes outward from the center of rotation of the first rotating member, and the other end of the valve rod. The viscous fluid coupling according to claim 1, further comprising: a magnetic attraction piece provided, and an electromagnet that faces the attraction piece and is separately arranged to be separated from the attraction piece. 3. A V-groove around which a V-belt for transmitting a driving force of an engine is wound is formed on a peripheral edge of the first rotating member, and the rotating shaft is connected to a driving shaft of a cooler compressor. The viscous fluid coupling according to 1 or 2. 4. The viscous fluid coupling according to claim 1, wherein a cooling fan is arranged around the periphery of the first rotating member, and a crankshaft pulley is coaxially fixed to the rotating shaft. 5. The viscous fluid coupling according to claim 4, wherein a radiator is arranged on the facing surface of the cooling fan, and the electromagnet is arranged on the radiator.