JPH10184356A - Fluid type fan coupling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lower the product cost of a fluid type fan coupling device by using an engine as a drive source. SOLUTION: In a fluid type fan coupling device, an one-way clutch 16 is provided between a journal box 14 directly connected to the shaft of a water pump driven by an engine and the drive shaft 12 of a fluid type fan coupling. When the rotating speed of the journal box 14 having unevenness in rotation increases, the one-way clutch 16 is locked to transmit the rotation of the journal box 14 to the drive shaft 12. When the rotating speed of the journal box 14 decreases, the one-way clutch 16 is run idle to interrupt the transfer of torque to the drive shaft 12 and prevent the unevenness in rotation from being generated on the drive shaft 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid type fan coupling device for cooling an automobile engine.

[0002]

2. Description of the Related Art As a fluid fan coupling device for controlling the rotation amount of a cooling fan according to the temperature change of air passing through a radiator, a fluid fan coupling device described in Japanese Patent Publication No. 8-23376 has been known. ing.

FIG. 7I shows the above-described fan coupling device. In this fan coupling device, a supply chamber 3 filled with a viscous fluid such as silicon oil and a driving chamber 4 in which a driver disk 10 is incorporated are provided in a case 2 supporting a cooling fan 1. A port 6 is formed in a partition plate 5 provided between the four, and an end of a leaf spring 7 for opening and closing the port 6 is fixed to the partition plate 5.

[0004] A bimetal 8 is mounted on the front surface of the case 2, and a pin 9 for pressing a leaf spring 7 is provided on the bimetal 8. When the temperature of the air passing through the radiator is equal to or lower than a set temperature, for example, 60 ° C., the bimetal 8 is in a flat state, and the pin 9 presses the leaf spring 7 and the leaf spring 7 closes the port 6. When the temperature of the air exceeds the set temperature, the bimetal 8 bends outward as shown in FIG. 7 (II), the pin 9 releases the pressing of the leaf spring 7, and the leaf spring 7
Elastically deforms to open the port 6.

When the temperature of the air that has passed through the radiator is lower than the set temperature of the bimetal 8 in the operating state of the fan coupling device having the above configuration, the port 6 is closed by the leaf spring 7 and the supply chamber 3 is closed. The viscous fluid inside does not flow into the driving chamber 4, and the viscous fluid in the driving chamber 4 is sent into the supply chamber 3 from the circulation hole 11 provided in the partition plate 5 by the rotation of the drive disk 10.

As a result, the amount of the viscous fluid in the driving chamber 4 becomes small, and the shearing resistance due to the rotation of the drive disk 10 becomes small, so that the torque transmitted to the case 2 is small and the fan 1 rotates at a low speed.

When the temperature of the air passing through the radiator exceeds the set temperature of the bimetal 8, the bimetal 8 bends outward and the pin 9 releases the pressing of the leaf spring 7, as shown in FIG. I do. At this time, since the leaf spring 7 is elastically deformed in a direction away from the partition plate 5, the port 6 is opened,
The viscous fluid in the supply chamber 3 flows from the port 6 into the driving chamber 4.

For this reason, the shear resistance of the viscous fluid due to the rotation of the driving disk 10 increases, the rotational torque applied to the case 2 increases, and the fan 1 rotates at high speed.

As described above, in the fan coupling device, the rotation speed of the fan 1 changes according to the change in temperature.
It has the characteristics that the warm-up is accelerated, the cooling of the cooling water is prevented, and the engine can be cooled effectively.

[0010]

In the above-described fluid fan coupling device, the drive shaft 12 provided on the drive disk 10 is connected to the pump shaft of a water pump, and the water pump is driven by an engine. Since the drive disk 10 is rotated by the rotation of the pump shaft, there are the following inconveniences.

That is, since an automobile engine is a multi-cylinder engine and has a compression and explosion process during one rotation of the crankshaft, the angular velocity of the crankshaft fluctuates during one rotation, causing torsional vibration and uneven rotation of the crankshaft. Occurs. Since the water pump is driven by the rotation of the crankshaft having the rotation unevenness, the rotation of the pump shaft is also uneven.

Rotational unevenness is greater at low engine speeds than at high engine speeds, and ± 10% at idling conditions.
It can be as high as a few percent. Since the pump shaft of the water pump rotates at about 1.3 times the engine speed, it rotates at about 1.000 rpm when idling.

In this case, if the engine temperature is low, the fan 1
Is equivalent to being disconnected from the drive shaft 12, and is equivalent to being connected at high temperatures.

As a result, the rotation unevenness applied to the drive shaft 12 from the pump shaft also acts on the fan 1,
The fluid-type fan coupling device needs to have not only a structure for withstanding high-speed rotation but also a stronger structure for withstanding large rotation unevenness (rotational vibration). Such a rigid structure results in an increase in the size of the fluid-type fan coupling device and an increase in product price.

This invention reduces the design strength of the fluid fan coupling device by reducing the rotational vibration transmitted from the pump shaft of the water pump driven by the engine to the fluid fan coupling. A technical issue is to reduce product costs.

[0016]

In order to solve the above-mentioned problems, according to the present invention, a supply chamber and a driving chamber filled with a fluid are provided in a case supporting a fan for cooling an engine. A port is formed in a partition plate provided therebetween, and an opening adjustment means for adjusting the opening of the port according to a change in ambient temperature is provided,
In a fluid-type fan coupling device in which a drive disk is incorporated in the driving chamber and the rotation of the drive disk is transmitted to a case via a viscous fluid flowing into the driving chamber, the drive disk is supplied from an engine to the drive disk. A one-way clutch is incorporated in the rotation torque transmission system that transmits rotation.

Here, the one-way clutch for transmitting the rotational torque from the engine to the drive disk is supported by fitting a shaft box to which the rotational torque of the engine is transmitted to a drive shaft connected to the drive disk. The one-way clutch may be supported by a box. In this case, it is preferable that a bearing is incorporated on both sides of the one-way clutch, a radial load is received by the bearing, a radial load acting on the one-way clutch is reduced, and the clutch is operated with high accuracy. Further, the one-way clutch may be incorporated between the drive disc and the fitting portion of the drive shaft.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Note that FIG.
The same parts as those of the conventional example are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIG. 1, a cylindrical shaft box 14 is provided on a drive shaft 12 which penetrates an end plate of the case 2 and is rotatably supported by a bearing 13.

The axle box 14 is connected to a pump shaft (not shown) of a water pump driven by the engine. For the connection, the axle box 14 is provided with a flange 15.

A one-way clutch 16 is provided inside the axle box 14.
And a pair of bearings 17 on both sides thereof. As shown in FIGS. 2 and 3, the one-way clutch 16 is formed of a roller-type one-way clutch. The one-way clutch 16 has an outer race 18 and an inner race 19. The outer race 18 is press-fitted into the inner diameter surface of the axle box 14, and the inner race 19 is press-fitted into the drive shaft 12.

A plurality of cam surfaces 22 forming a wedge-shaped space 21 between the inner surface of the outer ring 18 and the cylindrical outer surface 20 of the inner ring 19 are provided, and the cam surface 22 and the cylindrical outer surface 20 of the inner ring 19 are provided. Into the wedge-shaped space 21 formed therebetween, an engaging element 23 composed of a roller and an elastic body 24 for pressing the engaging element 23 toward a narrow portion of the wedge-shaped space 21 are incorporated.

When the outer race 18 rotates in the direction of the arrow in FIG. 3, the one-way clutch 16
And the cylindrical outer surface 20, the rotation of the outer ring 18
9 is transmitted. The rotation speed of the inner ring 19 is
When the rotation speed exceeds the rotation speed, the engagement element 23 is disengaged,
The outer ring 18 rotates freely.

As shown in FIG. 2, when the inner ring 19 of the one-way clutch 16 is shared with the inner ring of one bearing 17, the one-way clutch 16 and one bearing 17 can be assembled at the same time. Work can be facilitated.

The one-way clutch 16 is not limited to the one described above. For example, the inner ring 19 may be omitted, and the engaging element 23 may be disengaged from the cylindrical outer surface of the drive shaft 12. Further, a sprag may be incorporated between an outer ring having a cylindrical inner surface and an inner ring having an inner cylindrical outer surface.

Now, when the pump shaft of the water pump driven by the engine is directly connected to the axle box 14 and the axle box 14 is rotated, the axle box 14 is shown in FIG. As shown in the velocity diagram, (V + Δv)
Between (V−Δv) and (V−Δv).

When the speed of the axle box 14 increases, the one-way clutch 1
6 is engaged with the cam surface 22 and the cylindrical outer surface 20, and the rotation of the axle box 14 is controlled by the drive shaft 12.
Is transmitted to

When the speed of the axle box 14 starts to decrease, the rotational speed of the inner race 19 of the one-way clutch 16 exceeds the rotational speed of the outer race 18, so that the engagement member 23 is disengaged from the cam surface 22 and the cylindrical outer surface 20. As a result, the one-way clutch 16 becomes idle and torque is not transmitted to the drive shaft 12, and the rotation of the drive shaft 12 gradually decreases.

When the rotational speed of the drive shaft 12 decreases and becomes equal to the rotational speed of the axle box 14, the one-way clutch 16 is again locked, and the rotational torque of the axle box 14 is transmitted to the drive shaft 12. You.

As described above, when the rotational speed of the axle box 14 decreases, the rotational torque is not transmitted to the drive shaft 12, and when the rotational speed becomes equal to the rotational speed of the axle box 14, the rotational torque is transmitted to the drive shaft 12. As shown in the velocity diagram of FIG. 4, the drive shaft 12 generates only a rotation unevenness in a much narrower range than the rotation unevenness of the axle box 14, and the design of the fluid-type fan coupling device is reduced by the reduced rotation vibration. Strength can be reduced.

In FIG. 1, for convenience, the same components as those in FIG. 7 are shown. However, in actuality, the dimensions of each component can be made smaller than those in FIG. Thus, durability can be improved.

FIGS. 5 and 6 show another embodiment of the present invention. In this embodiment, the shaft box 14 of the fluid-type fan coupling device shown in FIG. 1 is omitted, and instead, the drive shaft 12 to which rotation from the engine is transmitted and the fitting portion of the drive disk 10 are provided. A one-way clutch 16 is incorporated.

The one-way clutch 16 has serrated teeth 27 formed on the inner periphery of an outer ring 26 which is press-fitted into an insertion hole 25 formed in the drive disk 10, and a pin is formed on an inner ring 28 which is press-fitted on the drive shaft 12. 29, a ratchet 30 is swingably mounted, and the ratchet 30 is attached to a spring 31.
And a ratchet-type one-way clutch which is pressed in the outer diameter direction to engage and disengage with the teeth 27.

As described above, by incorporating the one-way clutch 16 between the drive disk 10 and the drive shaft 12, the rotation of the drive shaft 12 is controlled by the one-way clutch 1.
When the rotation speed of the drive disk 10 exceeds the rotation speed of the drive shaft 12 having uneven rotation, the rotation transmission from the drive shaft 12 to the drive disk 10 is interrupted. Therefore, the rotational vibration of the drive disk 10 can be reduced.

Here, if the ratchet 30 in the one-way clutch 16 is formed of an elastic body, the ratchet 30
The torsional vibration transmitted from the drive shaft 12 to the drive disk 10 can be further reduced by the elastic deformation of the drive shaft 12.

In the embodiment, as the one-way clutch,
Although a roller-type one-way clutch and a ratchet-type one-way clutch are shown, the one-way clutch is not limited to these. For example, a sprag type one-way clutch may be used.

[0037]

As described above, in the present invention, the rotational torque of the engine is transmitted to the drive disk via the one-way clutch, so that the rotational vibration transmitted to the drive disk can be reduced. it can. Therefore, the design strength of the fluid coupling device can be reduced, and the product cost can be reduced.

By providing bearings on both sides of the one-way clutch, the bearing can receive a radial load. Therefore, the radial load acting on the one-way clutch is small, and the one-way clutch can be operated with high precision. Can be.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a fluid fan coupling device according to the present invention.

FIG. 2 is an enlarged cross-sectional view of the one-way clutch unit according to the first embodiment;

FIG. 3 is a sectional view taken along the line III-III of FIG. 2;

FIG. 4 is a velocity diagram of the drive shaft according to the first embodiment;

FIG. 5 is a sectional view showing another embodiment of the present invention.

FIG. 6 is a sectional view of the one-way clutch according to the first embodiment;

FIG. 7 (I) is a cross-sectional view of a conventional fan coupling device, and (II) is a cross-sectional view showing an operating state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cooling fan 2 Case 3 Supply chamber 4 Driving chamber 5 Partition plate 6 Port 10 Drive disk 12 Drive shaft 14 Shaft box 16 One-way clutch 17 Bearing

Claims (6)

[Claims] A supply chamber and a driving chamber filled with a fluid are provided in a case supporting a fan for cooling an engine, and a port is formed in a partition plate provided between the two chambers so that a change in ambient temperature can be prevented. An opening adjusting means for adjusting the opening of the port in response thereto is provided, a drive disk is incorporated in the driving chamber, and the rotation of the drive disk is transmitted to the case via a viscous fluid flowing into the driving chamber. A fluid fan coupling device, wherein a one-way clutch is incorporated in a rotation torque transmission system that transmits rotation from an engine to the drive disk in the fluid fan coupling device. 2. A one-way clutch for transmitting rotational torque from an engine to a drive shaft connected to the drive disk and passing through the case, and the one-way clutch is provided between the shaft box and the drive shaft. A fluid-type fan coupling device characterized by incorporating therein. 3. The fluid-type fan coupling device according to claim 2, wherein bearings are provided on both sides of the one-way clutch to rotatably support the drive shaft and the axle box. 4. The one-way clutch according to claim 1, wherein the one-way clutch is incorporated between the drive disk and a drive shaft supporting the drive disk and transmitting a rotational torque from an engine. Fluid fan coupling device. 5. The hydraulic fan coupling device according to claim 1, wherein said one-way clutch comprises a roller-type one-way clutch. 6. The hydraulic fan coupling device according to claim 1, wherein said one-way clutch comprises a ratchet type one-way clutch.