JPH03234929A - Viscous coupling - Google Patents

Abstract

PURPOSE:To prevent a fall of durability due to pressing force of an actuator by providing respective stopper parts for receiving the pressing force of the actuator and the reaction force thereof on a second transmitting member. CONSTITUTION:Oil pressure is supplied to the hydraulic port 99 of a hydraulic actuator 95 from a hydraulic power source through a control valve device, and a multiple disc clutch 73 is pressed with a piston 89 through a transmission system. In this case, the pressing force of the actuator 95 is applied on a stopper part 71, piston reaction force (pressing force reaction) on a cylinder member 77 side is applied on and received stopper member 87, and both forces are cancelled with each other in a hub 45 (a second transmitting member). Consequently, the pressing force of the actuator 95 is not applied between a housing 43 (a first transmitting member) and the hub 45 (a second transmitting member), and durability is not lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a viscous coupling that transmits torque through a viscous fluid.

(Prior art) ``Liquid friction clutch'' is disclosed in Japanese Patent Application Laid-Open No. 61-65918.
is listed. This is a viscous coupling that transmits torque by shearing resistance of viscous fluid between plates on the housing side and the hub side that are arranged to be relatively rotatable. A disc spring is disposed between each plate, and when pressed by an actuator, the disc spring bends to change the spacing between the plates, allowing the torque transmission characteristics to be adjusted.

(Problems to be Solved by the Invention) However, the actuator is integrated with or separate from the housing, and the retaining ring that receives the pressing force is attached to the hub side. Therefore, a pressing force acts on the contact portion between the hub and the housing, reducing the durability of the hub and the housing.

Therefore, an object of the present invention is to provide a viscous coupling whose durability does not deteriorate due to the pressing force of an actuator.

[Configuration of the Invention (Means for Solving the Problems) The viscous coupling of the present invention includes first and second transmission members arranged so as to be relatively rotatable, and the first and second transmission members.
a working chamber provided between the transmission members and filled with viscous fluid; a first plate connected to the first transmission member within the working chamber; and a second plate disposed opposite to the first plate. an engagement member disposed between the first and second plates and connected to the second transmission member so as to be movable in the axial direction; an actuator for fastening the second plate;
The second transmission member is characterized in that each stopper portion receiving the pressing force and its reaction force is provided.

(Operation) When the second plate is connected to the second transmission member via the engagement member due to the pressing force of the actuator, rotation of one side of the transmission member is caused by the shear resistance of the viscous fluid between the plates on each side. It is transmitted and rotates the other transmission member. The torque transmission characteristics can be adjusted by adjusting the fastening force between the engaging member and the second plate.

Since the pressing force of the actuator and its reaction force are canceled by each stopper section provided on the same transmission member,
It does not act between each transmission member, so durability does not decrease.

(Example) An example of the viscous coupling according to the present invention will be explained with reference to FIGS. 1(a) and 2(b) and FIG.

Figure 2 shows 4 using the viscous coupling according to the present invention.
The power system of a wheel drive vehicle is shown. In FIG. 2, the upper side of the paper indicates the front side in the longitudinal direction of the vehicle (direction of arrow A in the drawing), and the left-right direction of the paper indicates the width direction of the vehicle (direction of arrow B in the drawing).

First, the configuration of the power system of the vehicle shown in FIG. 2 will be explained.

This power system consists of an engine 1, a transmission 3, a center differential 5 (differential device between the front and rear wheels), a viscous coupling 7, a front differential 9 (differential device on the front wheel side), a front axle 11, 13, and left and right front wheels. 1
5.17, direction conversion gear group 19, propeller shaft 21
, a rear differential 23 (a differential device on the rear wheel side), a rear axle 25.27, left and right rear wheels 29.31, etc. This vehicle is also equipped with an anti-lock brake system.

The center differential 5 is the output gear 3 of the transmission 3.
3, the rotational driving force from the engine 1 input through the left and right side gears 35.37 is divided and outputted to the front axle 11.13. These gears 35.37 are connected to the inner and outer hollow shafts 39.41, respectively.

Next, the configuration of the viscous coupling 7 will be explained.

As shown in FIGS. 1(a) and 2(b) and FIG. 2, the housing 43 (first transmission member) and the hub 45 (second transmission member) are arranged to be relatively rotatable. The housing 43 is connected to the outer hollow shaft 41 by a spline 47, and the hub 45 is connected to the inner hollow shaft 39 by a spline 49. The hub 45 is hollow and connected to the differential case 51 of the front differential 9, and the left front axle 11 connected to the left side gear 53 of the front differential 9 is connected to the hub 4.
5 and the hollow shaft 39.

A control sleeve 55 (see FIG. 1(a)) passes through from the right side between the inner circumference of the housing 43 and the outer circumference of the hub 45 so as to be movable in the axial direction.

A working chamber 57 is formed between these members 43, 45, 55, and is filled with high viscosity silicone oil (viscous fluid). Housing 43, hub 45 and sleeve 55
X-rings 58 and 59 (seals having an X-shaped cross section) are arranged between the hub 45 and the sleeve 55, respectively, and an O-ring 6 between the hub 45 and the sleeve 55].

is arranged to keep the working chamber 57 liquid-tight.

FIG. 1(b) shows an enlarged view of the periphery of the working chamber 57. In this working chamber 57, outer and inner plates 63,65 are arranged alternating in the axial direction. The outer plate 63 (first plate) is spline connected to the inner circumference of the housing 43 so as to be movable in the axial direction. A ring 67 is provided on the inner edge side of the inner plate 65 (second plate).
(engaging members) are arranged alternately with the plates 65,
This ring 67 is spline connected to the outer periphery of the hub 45 so as to be movable in the axial direction.

On the left side of the left end ring 67 is a pressure receiving ring 69 that connects to the hub 45.
It is attached to and constitutes a pressing force stopper part 71 as described below. Further, the right end ring 67 faces the left end of the control sleeve 55. plate 65 and ring 6
7 and the pressure receiving ring 69 are pressed together by the sleeve 55 and fastened together. In this way, a multi-plate clutch 73 that connects the plate 65 and the hub 45 is configured. In addition,
The sleeve 55 is connected to the hub 45 through a connecting portion 75 so as not to rotate relative to each other, thereby preventing wear between the O-ring 61 and the hub 45 and the sleeve 55.

As shown in FIG. 1(a), a ring-shaped cylinder member 77 is disposed coaxially with the outer side of the hub 45 on the right side of the housing 43. As shown in FIG. Right end of knob 45 and cylinder member 7
A bearing 79 is arranged between the bearings 7 and 7. The bearing 79 is positioned with respect to the member 77 by a stepped portion 81 and a retaining ring 83. Further, a retaining ring 85 is attached to the right side of the bearing 79 on the hub 45, and constitutes a stopper portion 87 for a pressing force reaction force, which will be described later.

A piston 89 is fitted into the cylinder member 77 so as to be slidable in the axial direction. The sliding part of member 77.89 is O-ring 9
1.93, it is kept liquid-tight. In this way, a hydraulic actuator 95 (actuator) is configured. Piston 89 is connected to control sleeve 55 by bearing 97 and thus hydraulic actuator 9
A pressing force transmission system of No. 5 is constructed.

Hydraulic pressure is supplied from a hydraulic source to a hydraulic port 99 of the actuator 95 via a control valve device, and the piston 89 presses the multi-disc clutch 73 via the transmission system. At this time, the pressing force of the actuator 95 is applied to the stopper part 71, and the piston reaction force (pressing force reaction force) on the cylinder member 77 side is applied to and received by the stopper part 87, and is canceled out on the hub 45.

Therefore, unlike the conventional example, the pressing force of the actuator 95 is not applied between the housing 43 and the hub 45,
Durability does not decrease.

The actuator 95 can be operated manually from the driver's seat or automatically depending on steering conditions and road surface conditions, and is configured to stop operating when braking.

In this way, the viscous coupling 7 is constructed.

Next, the function of the viscous coupling 7 will be explained.

When the multi-plate clutch 73 is engaged by the hydraulic actuator 95, the plate 65 is engaged with the hub 45 with a strength corresponding to this engagement force. The rotation of the housing 43 due to the driving force from the engine 1 is transmitted from the plate 63 to the plate 65 due to the shear resistance of the silicone oil, and
3 to rotate the hub 45. At this time, if the rotational difference between the plates 63 and 65 is large, the differential limiting force will be large and a large torque will be transmitted, and if this rotational difference is small, the differential will be allowed and the transmitted torque will be small.

By adjusting the engagement force of the multi-disc clutch 73, the magnitude of the transmitted torque can be changed for the same rotational difference. When the multi-plate clutch 73 is locked, the rotation difference between the plates 63 and 65 becomes equal to the rotation difference between the housing 43 and the hub 45, and the transmitted torque becomes maximum. When the slippage of the clutch 73 is increased, the transmitted torque becomes smaller, and when the clutch 73 is released, the viscous coupling 7 becomes substantially in a torque-blocking state.

In this way, the torque transmission characteristics can be adjusted and the torque can be cut off.

Since the hub 45 and the housing 43 are connected to the left and right side gears 35 and 37 of the center differential 5, the functions of the viscous coupling 7 limit the differential movement of the center differential 5, cancel the differential limit, and change the difference. Adjustment of the dynamic limiting force is performed.

Next, the screw force according to the power characteristics of the vehicle shown in Figure 2 is 0. The function of the coupling 7 will be explained.

The rotation of the engine 1 is shifted by a transmission 3 and outputted to the front and rear wheels via a center differential 5. On the front wheel side, the applied driving force is divided and outputted to the left and right front wheels 15.17 via the front differential 9. On the rear wheel side, the applied driving force is dividedly output from the direction conversion gear set 19 and the propeller shaft 21 to the left and right rear wheels 29 and 31 via the rear differential 23.

When the multi-plate clutch 73 is engaged, the differential limiting force of the center differential 5 by the viscous coupling 7 is applied. Therefore, when one of the front and rear wheels spins on a rough road, the driving force is sent to the other wheel via the viscous coupling 7, so the vehicle does not get stuck, and its running performance is improved. Since the small rotational difference that occurs between the front and rear wheels when turning is absorbed by the viscous coupling 7, turning can be performed smoothly. Furthermore, the viscous coupling 7 also tolerates a small two-rotation difference during low-speed sharp turns such as U-turns and garage parking, so tight corner braking does not occur.

Furthermore, by adjusting the engagement force of the clutch 73, optimum straight-line stability and turning performance can be obtained.

When the crack 73 is opened (or when the fastening force is made sufficiently small), the differential rotation of the center differential 5 becomes free. During braking, this release is automatically performed, eliminating the rotational restraint between the front and rear wheels, preventing interference of braking forces, and protecting the normal functioning of the anti-lock brake system.

Note that the actuator, the multi-disc clutch, and each stopper portion may be provided on the housing side, and the pressing force and its reaction force may be canceled on the housing side.

Further, the actuator is not limited to the pressure actuator as in the embodiment, but may be an electromagnet, for example.

Note that in this embodiment, the ring 67 is connected to the second plate 65.
Although it is provided between the housing 43 and the hub 45, it is not limited thereto, and may be provided between the housing 43 and the first plate 63.

Further, in this embodiment, an example is shown in which a plurality of first plates 63 and second plates 65 are provided, but the first plate 63 and second plates 63 and 5 are not limited to this. It is sufficient if at least one pair of each is provided.

Further, in this embodiment, the ring 67 is used as an example of the engagement member, but the present invention is not limited to this, and other engagement members such as transmission means other than friction means may be used.

[Effects of the Invention] The viscous coupling of the present invention is configured such that each stopper part that receives the pressing force of the actuator and its reaction force is provided on one transmission member, and these forces are canceled out, so that the pressing force is reduced. There is no wear between the transmission members due to this, and durability does not deteriorate.

[Brief explanation of drawings]

Fig. 1 (a is a cross-sectional view of one embodiment, and Fig. 1 (b) is (a)
FIG. 2 is a skeleton mechanical diagram showing the power system of a vehicle to which the present invention is applied. 43... Housing (first transmission member) 45... Hub (second transmission member) 57... Working chamber 63... First plate, rate 65... Second plate 67. ...Ring (engaging member) 71.87...Stopper part 3 4 Hiroshi

Claims (1)

[Claims] first and second transmission members arranged to be relatively rotatable; a working chamber provided between the first and second transmission members and filled with a viscous fluid; a first plate connected to the transmission member; a second plate disposed opposite to the first plate; It includes an engaging member movably connected and an actuator that connects the engaging member and a second plate via a pushing force transmission system, and the second transmitting member receives the pushing force and its reaction. A viscous coupling characterized by having stopper portions that receive force.