JPH0474567B2 - - Google Patents

Description

[Detailed description of the invention] (b) Industrial application fields The present invention relates to viscous clutches.

(b) Conventional technology As a conventional viscous clutch, for example,
There is one shown in the -158765 publication. The viscous clutch has an outer cylindrical wall, an inner cylindrical wall, a number of clutch plates between the cylindrical walls, and side flanges on both sides of the cylindrical walls. The side flange and the inner cylindrical wall are sealed by an oil seal, thereby preventing leakage of the internal viscous fluid.

(c) Problems to be solved by the invention However, the conventional viscous clutch as described above
Since the oil seal is located axially adjacent to the clutch plate, there is a problem in that the overall axial dimension of the viscous clutch is increased. If such a viscous clutch with a large axial dimension is placed, for example, between the transfer (or final drive unit) of a four-wheel drive device and the propeller shaft, the clutch will be connected from the support of the rotating shaft of the transfer to the universal flange of the propeller shaft. The distance becomes longer, and vibrations and abnormal noises are more likely to occur. The present invention aims to solve these problems.

(d) Means for Solving the Problems The present invention solves the above problem by arranging the axial position of the oil seal so as to overlap the axial position of the clutch plate (arranging the oil seal inside the clutch plate). solve problems. That is, the present invention provides a viscous clutch 24 that is provided between the power transmission device 16 and the propulsion force transmission shaft 18, and includes an outer cylinder member 58 and a viscous clutch 24 that is formed integrally with the outer cylinder member 58 on both sides of the outer cylinder member. A chamber is formed by the power transmission device side side flange 60 and the propulsion force transmission shaft side side flange 62 which are integrally coupled, and the hub 52 arranged on the inner peripheral side of both side flanges, and the outer cylinder is installed in this chamber. A plurality of clutch plates 56 that rotate together with the member and a plurality of clutch plates 54 that rotate together with the hub are alternately arranged one on top of the other, and a chamber is filled with viscous fluid, and the hub is connected to the output shaft 40 of the power transmission device. This is aimed at a viscous clutch in which the side flange on the side flange of the propulsive force transmitting shaft is connected to the propulsive force transmitting shaft, and the hub has a spline portion 52b for coupling with the clutch plate, and It has a shaft portion 52a for coupling with the output shaft, and a wall portion 52c connecting the spline portion and the shaft portion, and the wall portion has an axial dimension smaller than the spline portion and the shaft portion, As a result, the convex portions 60a and 62a of both side flanges enter into the annular concave portions 82 and 84 formed between the spline portion and the shaft portion, and an oil seal seals between the concave portion and the convex portion. Bearings 66 and 72 are provided at positions opposite to the wall portions of the hubs of both oil seals, respectively, for supporting both side flanges with respect to the output shaft or the hub.
The bearing 64 provided on the side flange on the side of the power transmission device is a needle bearing, and the bearing 68 provided on the side flange on the side of the propulsion force transmission shaft is a ball or roller bearing capable of supporting a thrust load. It is characterized by being In this specification, the term "power transmission device" refers to a device that performs speed change, power distribution, etc., such as a manual transmission, automatic transmission, continuously variable transmission, transaxle, or transfer (power distribution device). This term is used to refer to a device that transmits power.

(E) Function Since the oil seal is disposed between the concave and convex portions on the inside of the clutch plate arrangement portion, the axial dimension of the viscous clutch is reduced. That is, the axial dimension required only for arranging the oil seal is no longer necessary. As a result, when this viscous clutch is applied to a four-wheel drive device, for example, the dimension from the support of the rotating shaft of the transfer (power transmission device) to the propeller shaft (propulsive force transmission shaft) becomes shorter, which reduces noise and vibration. It is advantageous in such respects. Furthermore, since the bearings are arranged adjacent to both oil seals, the oil seals can be reliably centered. The bearing on the power transmission side is a needle bearing, so
It is possible to prevent an increase in the radial dimension of the case of the power transmission device.

(F) Embodiments Hereinafter, embodiments of the present invention will be described with reference to Nos. 1 and 2 of the attached drawings.
This will be explained based on the diagram.

FIG. 2 schematically shows a four-wheel drive system having a viscous clutch to which the present invention is applied. engine 10
A transaxle 12 is disposed at the front of the vehicle in a facing direction (orthogonal to the direction in which the vehicle travels). The output from the transaxle 12 is transmitted to the left and right front wheels 14, and is also transmitted to the viscous clutch 24 by the transfer 16 (power transmission device).
and is transmitted to the final drive unit 20 via the propeller shaft 18. Furthermore, driving force is transmitted from the final drive unit 20 to the left and right rear wheels 22. A viscous clutch 24 is provided between the transfer 16 and the propeller shaft 18, which viscous clutch 24 is capable of transmitting increasing torque as the rotational differential increases.

FIG. 1 shows in detail a viscous clutch 24 according to the present invention. A left wheel drive shaft 28 and a right wheel drive shaft 30 are arranged on the left and right sides of the front wheel differential mechanism 26 of the transaxle 12. The countershaft 3 of the transfer 16 is parallel to the drive shaft 30.
2 is arranged, and the gear 34 that rotates together with the drive shaft 30 is the gear 36 of the countershaft 32.
They are interlocked. The countershaft 32 has a bevel gear 38 that rotates together with the countershaft 32, and the bevel gear 38 meshes with a bevel gear 42 provided on an output shaft 40 orthogonal to the countershaft 32. The output shaft 40 is rotatably supported by two bearings 46 and 48 with respect to a casing 44 of the transfer 16 (which is composed of a plurality of members). That is, the outer race 46a of the bearing 46 is fixed to the casing 44, the inner race 46b is fixed to the output shaft 40, and the outer race 48a of the bearing 48 is fixed to the casing 44.
4, and the inner race 48b is fixed to the output shaft 4.
Fixed to 0. A spacer 50 is provided between the inner race 46b and the inner race 48b. Hub 5 forming viscous clutch 24
2 is provided so as to rotate together with the output shaft 40 by a spline on its shaft portion 52a, and a large number of disc-shaped clutches are provided on the spline portion 52b on the outer periphery of the hub 52 so as to rotate together with the output shaft 40. A plate 54 is provided. The shaft portion 52a and the spline portion 52b are connected by a wall portion 52c. Since the axial dimension of the wall portion 52c is smaller than the axial dimensions of the shaft portion 52a and the spline portion 52b, recesses 82 are formed on both end surfaces of the hub 52.
and 84 are formed. Each clutch plate 54
Further clutch plates 56 are provided alternately in between. The clutch plate 56 is the outer cylinder member 5
It is provided so as to rotate together with 8. A small gap is formed between the clutch plates 54 and 56. Outer cylinder member 5
A side flange 60 on the unit side is integrally connected to one end of the outer cylinder member 58, and a side flange 62 on the propeller shaft side is integrally connected to the other end of the outer cylinder member 58. The flange 62 can also be formed in one piece).
The inner diameter side of the side flange 60 is connected to the shaft portion 5 of the hub 52.
2a by a needle bearing 64. The side flange 60 has a convex portion 60
a is provided, and this convex portion is connected to the aforementioned hub 52.
, and the space between the two is sealed by an oil seal 66. Further, the space between the side flange 60 and the casing 44 is sealed by an oil seal 67. Further, the side flange 62 is rotatably supported with respect to the output shaft 40 by a ball bearing 68 (which may also be a roller bearing) capable of supporting a thrust load. That is, the outer race 68a of the ball bearing 68 is fixed to the side flange 62, and the inner race 68b is fixed to the output shaft 40. In addition, the inner race 46b of the bearing 46, the spacer 50,
Inner race 48b of bearing 48, hub 5
2 and the inner race 68b of the ball bearing 68 are restrained in the axial direction by being tightened together by a nut 70 screwed into the end of the output shaft 40. Also, the side flange 6
The second convex portion 62a enters into the concave portion 84 of the hub 52, and the space between the two is sealed by an oil seal 72. This and the aforementioned oil seal 66 allow the clutch plate 54 and the clutch plate 56 to be sealed. The space in which it is located is sealed.
This sealed space is filled with viscous fluid. The side flange 62 is connected to a propeller shaft flange yoke 74 by bolts 76. The end surface of the side flange 62 on the propeller shaft side is sealed by a cap-shaped sealing member 78. A through hole 80 is provided in the center of the output shaft 40, passing through from one end to the other end. The propeller shaft flange yoke 74 is provided to rotate together with the propeller shaft 18.

Next, the operation of this embodiment will be explained. The driving force of the engine 10 is transmitted to the front wheels 14 after a predetermined speed change by the transaxle 12, and is also transmitted to the front wheels 14 by the transaxle 16 and the viscous clutch 2.
4. The power is transmitted to the rear wheels 22 via the propeller shaft 18 and the final drive unit 20.
As a result, the vehicle is always in four-wheel drive. Because the viscous clutch 24 is provided, the front wheels 14 and the rear wheels 2 are
Even if a rotation difference occurs between the clutch 24 and the viscous clutch 24,
It can be absorbed by. In addition, the front wheel 14
Even if any one of the rear wheels 22 is in a no-load state, driving force can be transmitted to the other wheels.

The hub 52 of the viscous clutch 24 rotates together with the output shaft 40, while the outer cylinder member 58, side flange 60, and side flange 62 rotate together with the propeller shaft 18, so that the hub 52 and side flanges 60 and 62 rotate together with the propeller shaft 18. Although relative rotation occurs between them, the space between them is sealed by oil seals 66 and 72. Therefore, the viscous liquid filled around the clutch plates 54 and 56 will not leak to the outside. Because oil seals 66 and 72 are located in the same axial location as clutch plates 54 and 56, the overall axial dimension of viscous clutch 24 is shortened. Therefore, the overhang dimension from the bearings 46 and 48 that support the output shaft 40 to the casing 44 to the propeller shaft flange yoke 74 is shortened, making it difficult for noise, vibration, etc. to occur.

(G) Effects of the Invention As explained above, according to the present invention, the oil seal between the side flange of the viscous clutch and the hub is arranged to overlap with the clutch plate in the axial direction, so that the axial dimension is small. It can be a viscous clutch. Further, since the bearings are arranged adjacent to both oil seals, it is easy to center the oil seals, and a reliable seal can be achieved. Furthermore, since the bearing on the power transmission device side is a needle bearing, there is no need to increase the diameter of the case of the power transmission device.

[Brief explanation of drawings]

FIG. 1 shows a viscous clutch according to the invention;
Fig. 2 shows a four-wheel drive system to which the viscous clutch according to the present invention is applied.
It is a figure showing the whole wheel drive device. 12...Transaxle, 14...Front wheel, 1
6...transfer (power transmission device), 18...
...Propeller shaft (propulsive force transmission shaft), 20...
... Final drive unit, 22 ... Rear wheel,
24... Viscous clutch, 40... Output shaft, 44...
...Casing, 52...Hub, 52a...Shaft part,
52b...spline part, 52c...wall part, 54
...Clutch plate, 56...Clutch plate, 58...Outer cylinder member, 60...(Power unit side) side flange, 60a...Protrusion, 62...
...(propulsive force transmission shaft side) side flange, 62a
...Protrusion, 64...Needle bearing, 66...
...Oil seal, 68...Ball bearing, 7
2... Oil seal, 82, 84... Recess.

Claims (1)

[Scope of Claims] 1. A viscous clutch provided between a power transmission device and a propulsion force transmission shaft, comprising an outer cylinder member and integrally formed with or integrally connected to both sides of the outer cylinder member. A chamber is formed by the side flange on the side of the power transmission device and the side flange on the side of the propulsion transmitting shaft, and the hubs arranged on the inner circumferential side of both side flanges. A plurality of clutch plates and a plurality of clutch plates that rotate together with a hub are alternately arranged one on top of the other, and a chamber is filled with viscous fluid,
In a viscous clutch in which a hub is connected to the output shaft of a power transmission device and a side flange on the side of the propulsion transmission shaft is connected to the propulsion transmission shaft, the hub has a spline portion for coupling with the clutch plate and a spline portion that connects the power transmission device. It has a shaft part for coupling with the output shaft of and a wall part that connects the spline part and the shaft part, and the wall part has an axial dimension smaller than the spline part and the shaft part. The convex portions of both side flanges fit into the annular concave portion formed between the spline portion and the shaft portion, and an oil seal is provided between the concave portion and the convex portion to seal the space between the two. Bearings for supporting both side flanges with respect to the output shaft or the hub are provided at positions opposite to the wall portion of the hub of the oil seal,
A viscous clutch characterized in that the bearing provided on the side flange on the power transmission device side is a needle bearing, and the bearing provided on the side flange on the propulsion force transmission shaft side is a ball or roller bearing capable of supporting a thrust load.