JPH02309019A - Viscous coupling - Google Patents

Abstract

PURPOSE:To enhance the rising characteristic in torque transmission at the time of differential revolution by providing a radially directed opening it at least one of the resistance boards, and forming a boss at one side-edge of each opening. CONSTITUTION:The torque given to a shaft 19 is transmitted to a resistance board 43 through the action of another resistance board 47, which rotates in a single piece with the shaft 19, and the resistance of a viscous fluid encapsulat ed in a working chamber 23, and further to a case 21 rotating in a single piece with the resistance board 43 to finally reach the output part 29. When the shaft 19 and a cable 21 are in high-speed differential rotation, the liquid temp. in the working chamber 23 rises to boost the internal pressure, and the resis tance boards 43, 47 contact each other. At this time, a boss 53 on the resistance board 47 cuts the oil film formed between it and the resistance board 43, resulting in metal contacting of these boards 43, 47 so as to generate hump torque, that will provide a substantially direct transmission of the torque. As the boss 53 is provided at one side of an opening 51, guidance of the viscous fluid is made smooth, which will smoothen the movement of the resistance board 47.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a viscous coupling used, for example, in a power transmission device of a vehicle.

(Prior Art) As a conventional viscous coupling of this type, there is one described, for example, in Japanese Patent Application Laid-open No. 58-50349@. This viscous coupling is built into the power distribution system of four-wheel drive vehicles, and the resistance plates rotate in the direction of rotation within the viscous fluid such as silicone oil sealed in the operating chamber. They are engaged and arranged alternately, and when differential rotation occurs between the front wheel side and the rear wheel side, the differential rotation of the resistance plates is limited by the viscous paper resistance of the viscous fluid.

In a four-wheel drive vehicle equipped with such a device,
When the rear wheels fall into muddy ground or the like, causing differential rotation between the front and rear wheels, the viscous coupling limits the differential movement, making it possible to escape from the rough road. Furthermore, when the rear wheels are slipping at high speed, the temperature of the liquid in the working chamber rises, causing the internal pressure to rise, and when this exceeds a certain value, the resistance plates of the working blank come into close contact with each other. Due to this close contact, the transmission torque of the viscous coupling rapidly increases, and a so-called hump torque is obtained, making it possible to escape from a rough road.

(Problem to be solved by the invention) However, in such conventional viscous couplings, each of the resistance plates on the shaft side and the case side was formed into a flat plate shape, so the resistance was reduced during high-speed differential rotation. When the plates come into contact with each other, the oil film formed between the resistance plates cannot be cut, and the plates come into contact through this oil film. For this reason, there is a problem in that the speed at which the transmitted torque rises is impaired, and it becomes impossible to quickly escape from the rough road.

Therefore, an object of the present invention is to provide a viscous coupling that can improve the rise characteristics of transmitted torque.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a system that is formed between a first rotating body and a second rotating body that are relatively rotatable, and a viscous fluid is sealed therein. A viscous coupling comprising a working chamber, and a plurality of resistance plates that are alternately arranged in engagement with the first rotary body and the second rotary body in the rotational direction, respectively, in the working chamber. A radial opening is provided in at least one side of the resistance plate, and a protrusion is formed at one side edge of the opening.

(Function) According to the above configuration, during high-speed differential rotation, the oil film is cut by the projections of the resistance plates, and the resistance plates are brought into metal contact with each other and quickly brought into close contact.

(Example) Embodiments of the present invention will be described below based on the drawings.

Fig. 1 is a longitudinal sectional view of a viscous coupling device according to an embodiment of the present invention, Fig. 2 is a plan view of the shaft 1/ft side resistance plate, and Fig. 3 is a sectional view taken along the line ■-■ in Fig. 2. , FIG. 4 shows a schematic diagram of a four-wheel drive vehicle to which a viscous coupling device according to the present invention is applied.

As shown in FIG. 4, an engine 1 and a transmission 3 are arranged horizontally at the front of the vehicle. The output from the transmission 3 is transmitted to the left and right front wheels 7 via the l-transfer 5 on the one hand, and to the final drive unit 13 via the viscous coupling 9 and propeller shaft 11 on the other hand. The signal is transmitted from the drive unit 13 to the left and right rear wheels 15.

The viscous coupling 9 has a characteristic of transmitting a small amount of torque when a slight difference in rotational speed occurs between the input shaft and the output side, and transmits an extremely large torque in response to a large difference in rotational speed. It has the function of

This viscous coupling 9, as shown in FIG.
A case 21, which is a second rotary body, is fitted to the outer periphery of a shaft 19, which is a first rotary body that has seven flange 17 as a first connecting portion on one end side and receives rotational input, so as to be relatively rotatable. A working chamber 23 is provided between the shaft 19 and the case 21 and is formed in a compact manner. The flange 17 is connected to a flange provided on an output shaft (not shown) of the transfer 5.

The case 21 is formed by fitting an output part 29 as a second connecting part to the open end side of a cylindrical outer cylinder 27 having a side wall 25 on one end side, and integrating the two parts by welding or the like. A flange of a universal joint (not shown) is connected to the output portion 29, and the propeller shaft 11
are connected.

The case 21 is rotatably supported by the annular protrusion 31 of the side wall 25 and the two output parts via bearings 33.degree. 35 relative to the shaft 19. A sealing member 37 is provided on the side wall 25 of the case 21 and the two output parts for the shirts l to 19.
39 are provided.

And made by seal member 37.39! [23 is formed tightly, and this working chamber 23 is filled with a viscous fluid such as silicone oil.

Inside the working chamber 23, there are a plurality of resistance plates 43 engaged in the rotational direction by splines 41 formed on the inner peripheral wall of the outer cylinder 27 of the case 21, and a spline 4.5 formed on the outer periphery of the shaft 19. a plurality of resistance plates 4 engaged in the rotational direction with
7 are arranged alternately, and a positioning spacer ring 49 for maintaining a predetermined interval between the resistance plates 43 on the case 21 side is inserted between each resistance plate 43 so as not to contact the outer periphery of the resistance plate 47 on the shaft 19 side. has been done.

As shown in FIG. 2, the resistance plate 47 on the shaft 19 side has a radial opening 5 which is IJfl at the peripheral edge position.
1 are formed radially at equal angular intervals, and a protrusion 53 that is bent to one side when the frontage 51 is formed is formed on the rear opening edge of each opening 51 in the rotational direction.

In this embodiment, the opening 51 and the protrusion 53 are formed on the resistance plate 47 on the shaft 19 side, but the opening 51 and the protrusion 53 may be formed on the resistance plate 43 on the case 21 side. The anti-plates may be formed at 43° and 47°.

Next, the operation of the above embodiment will be explained.

After the driving force of the engine 1 is subjected to a predetermined speed change by the transmission 3, it is transmitted to the front wheels 7 via the transfer 5, and is transmitted to the front wheels 7 via the viscous coupling 9, propeller shaft 11 and final drive unit 13 on the other hand. 15.

The rotational force input from the transfer 5 to the shaft 19 of the viscous coupling 9 is transmitted to the resistance plate 43 through the resistance plate 47 that rotates integrally with the shaft 19 and the viscous resistance of the viscous fluid sealed in the actuator W23. , is transmitted to the case 21 which rotates integrally with the resistance plate 43, and is transmitted to the propeller shaft 11 connected to the output section 29 via a universal joint.

In the torque transmission of the viscous coupling 9 performed in this manner, during high-speed differential rotation between the shaft 19 and the case 21, the temperature of the liquid in the working chamber 23 is TR, and the internal pressure increases, and the resistance plate 43 and the resistance plate 47 At this time, the projections 53 of the resistance plates 47 on the shaft 19 side cut the oil film formed between the resistance plates 43 on the case 21 side. As a result, the resistance plate 43 and the resistance plate 47 come into metal contact and quickly come into close contact with each other to obtain a hump torque, and substantially direct torque transmission is obtained, making it possible to quickly escape f3 when driving on a rough road. Further, since the protrusion 53 is provided on one side of the opening 51, the protrusion 53
The viscous fluid 1 is guided smoothly, and the resistance plate 47 moves smoothly.

[Effects of the Invention] As is clear from the above description, according to the configuration of the present invention, the torque transmission rise characteristic during differential rotation can be improved, and escape from rough roads can be quickly and easily performed. be able to.

[Brief Description of the Drawings] Fig. 1 is a longitudinal sectional view of a viscous coupling according to an embodiment of the present invention, Fig. 2 is a plan view of a shaft-side resistance plate, and Fig. 3 is a - - - - of Fig. 2. A line sectional view and FIG. 4 are schematic diagrams of a four-wheel drive vehicle to which a viscous coupling according to the present invention is applied. 19...Shaft (first rotating body) 21...Case (second rotating body) 33...Working chamber 43.47...Resistance plate 53...Protrusion Figure 3 19...ShiV Foot (first rotating body) 21... Case (second rotating body) 33... To operation 43.47... Resistance plate 53... Protrusion Fig. 1

Claims (1)

[Claims] a working chamber formed between a first rotary body and a second rotary body that are relatively rotatable and filled with a viscous fluid; In a viscous coupling comprising a plurality of resistor plates arranged alternately, at least one of the resistor plates is provided with a radial opening, and a protrusion is provided at one edge of the opening. A viscous coupling characterized by forming a viscous coupling.