JPH04157216A - Viscous coupling - Google Patents

Abstract

PURPOSE:To obtain a one-way clutch with large torque transmission capacity by providing an engagement means having notches and engagement elements passing through the notches in axial direction in the engagement part of one of the 1st and 2nd plates. CONSTITUTION:When an inner plate 36 and a hub 22 are rotated in the arrow directions 90 and 92, respectively, each roller 24 rolls into the narrow portion 84 of each notch 66 mesh and place the inner plate and the hub in linking motion. When they are rotated in the reverse directions, respectively, the meshing is released to eliminate mutual linkage. The rollers 24 are always kept at equal intervals by means of a spacer plate 38 to evenly distribute the surface pressure acting on the notches 66. Thus a one-way clutch for obtaining a large transmission torque between the inner plate (1st transmission member) and hub (2nd transmission member) is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a viscous coupling that transmits torque via viscous fluid.

[Conventional technology]

Generally, when a viscous coupling is used as a power transmission device between the front and rear axles of a four-wheel drive (4WD) vehicle, for example, by blocking torque transmission from the output shaft to the input shaft, the coupling between the front and rear wheels during braking is used. A one-way clutch is used to prevent interference between braking forces. However, in the past, the viscous coupling and the one-way clutch were provided side by side in the axial direction, so such a power transmission device had the disadvantage that the length in the axial direction became large.

Therefore, in the "power transmission device" described in JP-A No. 62-118126, a one-way clutch is inserted into the hub of a viscous coupling, and a one-way clutch is inserted between one of the output shafts and the hub. By interposing it, the axial length is shortened and compactness is achieved. If this device is placed between the front wheels and rear wheels of a 4WD vehicle, even if the front wheels lock during braking, the locking force will be cut off and the rear wheels will be prevented from locking due to this locking force, thereby preventing anti-lock brakes. The normal functioning of the system (ABS) can be protected.

[Problem to be solved by the invention]

However, in this configuration in which the one-way clutch is placed between the hub and shaft of the viscous coupling, the diameter of the one-way clutch must be small, so the torque transmission capacity is insufficient and it is difficult to transmit large torque. The problem is that it can't be done.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems, and to provide a compact viscous coupling having a one-way clutch function with a large torque transmission capacity.

[Means to solve the problem]

The above object of the present invention is to provide first and second transmission members arranged to be relatively rotatable, a working chamber filled with a viscous fluid,
a first set of plates engaged with a first transmission member; and a second set of plates arranged alternately with the first set of plates in the working chamber and engaged with a second transmission member. A viscous coupling having the first and second
The engagement portion of at least one of the plate sets includes notches formed at equal intervals in the circumferential direction, engaging elements passing through the notches of each plate in the axial direction, and engaging elements arranged at equal intervals. This is achieved by a viscous coupling characterized in that there are a plurality of engaging means that non-rotationally engage in only one direction, consisting of a spacing plate for holding.

[Effect]

Since the engaging means having a one-way clutch function is disposed between the transmission member and the plate assembly, the diameter of the rotational torque transmission portion of the one-way clutch becomes larger, and the torque transmission capacity can be increased.

[Embodiment 11] Hereinafter, a first embodiment of the present invention will be described in detail based on the attached FIGS. 1 to 6 and FIG. 15.

First, FIG. 15 shows a 4WD using an embodiment of the present invention.
The configuration of a vehicle's power system will be explained. This power system consists of an engine 1, a transmission 3, a front differential 5 (differential device on the front wheel side), front axles 7 and 9, and left and right front wheels 1.
1, 13, transfer 1 including direction conversion gear set 15
7. Viscous coupling 18 of this example ml11, propeller shaft 21, rear differential 23 (differential device on the rear wheel side), rear axle 25°27, left and right rear wheels 29.
It consists of 31 etc.

Next, the viscous coupling 1 is shown in FIGS. 1 to 6.
The configuration of No. 8 will be explained. The housing 20 (first transmission member) and the hub 22 (second transmission member) are arranged to be relatively rotatable. The hub 22 is connected to the connecting shaft 4 by a spline 32.
3 is spline-fitted to the housing 20 and this connecting shaft 4.
A bearing 48 is disposed between the two. Furthermore,
A bearing 60 and a seal 62 are arranged between the housing 20 and the hub 22, and the housing 20 and the connecting shaft 43 are arranged so as to be relatively rotatable.

In order to fix the bearing 48 in the axial direction, the connecting shaft 4
A washer 50 and a lock nut 54 are attached to the housing 20, and a retaining ring 52 is attached to the housing 20. The housing 20 is flange-connected to the transfer 17 side by bolts screwed into bolt holes 58, and is rotationally driven by the driving force from the engine l. The connecting shaft 43 is connected to the propeller shaft 21 side.

A working chamber 40 is formed between the housing 20 and the hub 22, and this working chamber 40 is filled with highly viscous silicone oil (viscous fluid). Further, an X-ring 28,30 (a seal having an X-shaped cross section) is arranged between the housing 20 and the hub 22 to keep the working chamber 40 liquid-tight.

As shown in an enlarged view in FIG. 2, inside the working chamber 40, outer plates 34 (first plate set) and inner plates 36 (second plate set) are arranged alternately, and the rotation axis Spacer plates 38 are arranged inside the outer plates 34 located at both ends in the direction. The outer plate 34 is the housing 20
The outer plates 34 are spline-coupled to the outer plates 34 so as to be movable in the axial direction by spline engagement means 44 provided between the outer plates 34 and the inner circumference, and a spacer ring 46 is disposed between each outer plate 34 .

As shown in FIG. 3, on the inner periphery of each inner plate 36, notches 66 having sloped surfaces whose distance from the outer periphery decreases along the circumferential direction are formed at equal intervals. The notch 6 of each inner plate 36 is located in the opening formed by the notch 66 and the outer peripheral surface of the hub 22.
A cylindrical roller 24, which is an engaging element, is arranged to pass through the rollers 6 in the axial direction, and the inner periphery of the spacing plate 38 is provided with cuts for holding the rollers 24 at equal intervals, as shown in FIG. A holding portion 68, which is a cutout, is formed, and a so-called one-way clutch 42 is configured. Note that both end surfaces of the roller 24 are fitted with retaining rings 2 attached to the hub 22.
6 restricts movement in the axial direction.

That is, as shown in FIG. 6, when the inner plate 36 and the hub 22 rotate relative to each other in the directions of arrows 90 and 92, the roller 24 moves into the narrow portion 84 of the notch 66.
The inner plate 36 and hub 2
Link 2. Further, as shown in FIG. 5, the inner plate 36 and the hub 22 are aligned with arrows 86 and 8, respectively.
When the roller 24 rotates relatively in the direction 8, the roller 24 moves into the notch 6.
The inner plate 36 and the hub 22 are disengaged by rolling to a wide portion 82 of the inner plate 36 and the hub 22 is released.

At this time, since each roller 24 is always maintained at equal intervals by the spacing plate 38, all the rollers 24
4 are rolled simultaneously in the same direction. Therefore, for each inner plate 36, the surface pressure acting on the slope of each notch 66 becomes uniform, and only the surface pressure of the slope of the notch 66 at the negative portion does not become high. Therefore, although the inner plate 36 is formed of a very thin metal plate, the inclined surface of the notch 66 can transmit a large torque without being deformed or damaged.

Therefore, the rotation of the housing 20, which is rotationally driven by the driving force from the engine l, is transmitted from the outer plate 34 to the inner plate 36 due to the shear resistance of the silicone oil, and this inner plate 36 applies the torque of the one-way clutch 42 to the hub 22. When the wheels rotate relative to each other in the transmission direction, the driving force is transmitted to the rear wheels 29 and 31. Also,
When the inner plate 36 rotates relative to the hub 22 in a direction opposite to the torque transmission direction of the one-way clutch 42, the driving force is cut off and no torque is transmitted to the rear wheel side.

When drive torque is transmitted to the rear wheels, the rotational speed associated with the relative movement between the outer plate 34 and the inner plate 36 (between the front and rear axles) is determined based on the torque transmission characteristics of the viscous coupling. The larger the difference, the larger the transmitted torque, and the smaller the rotational speed difference, the smaller the transmitted torque. Furthermore, since the one-way clutch 42 is configured on the outer circumferential side of the hub 22, the diameter of the rotational torque transmitting portion of the one-way clutch 42 becomes larger and the torque transmission capacity can be increased. Can transmit driving force.

Next, the function of the viscous coupling 18 will be explained based on the power performance of the vehicle shown in FIG. Note that the one-way clutch 42 is arranged so that driving force can be transmitted when the vehicle is traveling forward.

The rotation of the engine 1 is transmitted to the front differential 5 via the transmission 3, and dividedly output to the left and right front wheels 11. The output is divided to the rear wheels of 29.31.

When the difference in rotational speed due to the relative movement between the front and rear axles is small, such as when driving on a good road, the difference in rotational speed is absorbed by the viscous coupling 18, and almost no driving force is transmitted to the rear wheels 29, 31. Therefore, the vehicle is in a 2WD state with front wheel drive, which improves fuel efficiency and prevents tight corner braking even when making low-speed sharp turns such as parking or making a U-turn.

When the front wheels 11 and 13 spin on rough roads, a difference in rotational speed occurs between the front and rear axles, and the rotation of the housing 20 and the hub 22
When there is a large difference in rotational speed between the rotation of the viscous coupling 18 and the rotation of
Since the output is divided at 9.31 and the vehicle enters the 4WD state, high drivability can be obtained.

Furthermore, in the above embodiment 11, the inner plate 3
6 is engaged with the hub 22 via a one-way clutch 42. Therefore, when a difference in rotational speed occurs between the rotation of the housing 20 and the rotation of the hub 22, such as when the front wheel locks and the rear wheel rotates at a higher speed than the front wheel, for example during braking, the inner plate 36 rotates relative to the hub 22 in the direction of arrow 86 in the figure, so the difference in rotational speed is irrelevant (the transmission of driving force between the front wheels and the rear wheels is automatically cut off, and the rear wheels It remains in a disconnected state. Therefore,
Interference between braking forces between the front and rear wheels during braking is prevented, front wheel locking does not induce rear wheel locking, and the normal function of the anti-skid braking system (ABS) is protected.

Next, the structure of the viscous coupling 19 based on the second embodiment of the present invention will be explained with reference to FIGS. 7 to 12.

The viscous coupling 19 of the second embodiment is arranged, for example, in the same position as the viscous coupling 1B of the first embodiment in the vehicle shown in FIG. 15.

The housing 33 (first transmission member) and the hub 35 (second transmission member) are arranged to be relatively rotatable.

The housing 33 is spline-fitted to the output shaft 39 on the transfer 17 side by an integral spline 37, and is rotationally driven by the driving force from the engine 1. The knob 35 is connected to a connecting shaft 43 of the propeller shaft 21 through a spline 41.

A working chamber 45 is formed between the housing 33 and the hub 35, and this working chamber 45 is filled with highly viscous silicone oil (viscous fluid). Furthermore, X rings 47, 49 (seals having an X-shaped cross section) and backup rings 51, 53 are arranged between the housing 33 and the hub 35 to keep the working chamber 45 liquid-tight.

As shown in an enlarged view in FIG. 8, outer plates 55 (first plate set) and inner plates 57 (second plate set) are arranged alternately inside the working chamber 45, and the rotation axis Spacing plates 56 are arranged on the outer sides of the inner plates 57 located at both ends in the direction. The inner plates 57 are spline-connected to the outer periphery of the hub 35 by spline engagement means 59 so as to be movable in the axial direction, and a spacer ring 61 is disposed between each inner plate 57 .

As shown in FIG. 9, on the outer periphery of each outer plate 55, notches 63 having sloped surfaces whose distance from the inner periphery decreases along the circumferential direction are formed at equal intervals. A roller 65, which is an engaging element passing through the notch 63 of each outer plate 55 in the axial direction, is disposed in the opening formed by the notch 63 and the inner circumferential surface of the housing 33. On the outer periphery of the holding plate 56, as shown in FIG. 1O, holding portions 64, which are notches that hold the respective rollers 65 at equal intervals, are formed, forming a so-called one-way clutch 67.

That is, as shown in FIG. 12, when the housing 33 and the outer plate 55 rotate relative to each other in the directions of arrows 71 and 72, the roller 65 rolls to the narrow part 73 of the notch 63 and engages with the housing 33. and the outer plate 55 are interlocked. Further, as shown in FIG. 11, when the housing 33 and the outer plate 55 rotate relative to each other in the directions of arrows 75 and 76, the roller 65 rolls to the wide part 77 of the notch 63 and is disengaged. Housing 33 and outer plate 5
Cancel linkage of 5.

At this time, since each roller 65 is always maintained at equal intervals by the spacing plate 56, all the rollers 65
5 are transferred in the same direction at the same time. Therefore, for each outer plate 55, the surface pressure acting on the sloped surface of each notch 63 becomes uniform, and only the surface pressure on the sloped surface of the notch 63 at the negative part does not become high. Although the outer plate 55 is formed of a very thin metal plate, the inclined surface of the notch 63 can transmit a large torque without deforming or breaking.

Therefore, when the housing 33, which is rotationally driven by the driving force from the engine l, rotates relative to the outer plate 55 in the torque transmission direction of the one-way clutch 67,
The rotation of the housing 33 is transmitted from the outer plate 55 to the inner plate 57 due to the shear resistance of the silicone oil, and the driving force is transmitted from the inner plate 57 to the rear wheels 29 and 31 via the hub 35. Further, when the housing 33 rotates relative to the outer plate 55 in the direction opposite to the torque transmission direction of the one-way crunchy rotor 7,
The driving force is cut off and torque is not transmitted to the rear wheels.

When the drive torque is transmitted to the rear wheel side, the rotation speed due to the relative movement between the outer plate 55 and the inner plates 1 and 57 (between the front and rear axles) is determined based on the torque transmission characteristics of the viscous coupling. The larger the difference, the larger the transmitted torque, and the smaller the rotational speed difference, the smaller the transmitted torque. Also, the one-way clutch 67 is connected to the housing 33.
Since it is configured on the inner peripheral side of the keyaki viscous coupling 18 of the first embodiment, the diameter of the rotational torque transmission part is larger than that of the one-way clutch 42 of the keyaki viscous coupling 18 of the first embodiment, and the torque transmission capacity can be further increased. Even more driving force can be transmitted to the rear wheels.

Furthermore, since the outer plate 552, the interval retaining plate 56, and the inner plate 57 have different thicknesses, and the outer plate 55 and the interval retaining plate 56 are formed thicker, the cutout portion 63 may dig into the roller 65. It can be prevented from being put away. Further, the function of the viscous coupling 19 itself and the function corresponding to the power performance of the vehicle are the same as the viscous coupling 1 of the first embodiment.

Next, the structure of a viscous coupling 79 based on a third embodiment of the present invention will be explained with reference to FIGS. 13 and 14. The viscous coupling 79 of the third embodiment is also arranged at the same position as the viscous coupling 18 of the first embodiment in the vehicle shown in FIG.

As shown in FIG. 13, the hub 81 is arranged relatively rotatably inside the housing 97, and a working chamber 83 filled with high-viscosity silicone oil is formed therebetween.

As shown in an enlarged view in FIG. 14, an inner plate 85 is spline-engaged to the front end of the hub 81 inside the working chamber 83, and an inner plate 99 is connected to the rear end via a one-way clutch 87. is engaged. Further, the outer plates 100 are spline-connected to the inner periphery of the housing 97 so as to be movable in the axial direction by spline engagement means 101, and a spacer ring 102 is disposed between each outer plate 100. . And each inner plate 85.99
are arranged alternately with the outer plate 100, respectively,
The inner plate 85 is connected to the outer plate 100 and the first
The inner plate 99 constitutes the outer plate 100 and the second plate group 91. The one-way clutch 87, which is the engagement means for the inner plate 99, is similar to the one-way clutch 4 described above.
The roller 93 has a spacing plate 103 and a roller 93 having the same configuration as the roller 93, and a washer 69 is disposed between the rear end surface of the roller 93 and the housing 97.
Movement of the front side end surface of No. 3 in the axial direction is restricted by a retaining ring 95 disposed on the hub 81.

Therefore, when the housing 97 and the hub 81 rotate relative to each other in the torque transmission direction of the one-way clutch 87, a large driving force is transmitted to both the first and second plate groups 89 and 91. Further, when the housing 97 and the hub 81 rotate relative to each other in the direction opposite to the torque transmission direction of the one-way clutch 87, the driving force is transmitted only by the first plate group 89, so that the transmitted torque becomes small.

In the vehicle shown in FIG. 15, the one-way clutch 87 of the viscous coupling 79 is arranged to be able to transmit torque when the vehicle is traveling forward. Therefore, the driving force transmitted through the first plate group 89 allows the vehicle to travel in 4WD even when traveling backwards.

Incidentally, the engaging means having the one-way clutch function as described above may be constructed based on other one-way clutch types such as a sprag type or a claw clutch type. Further, in each of the embodiments B described above, a pair of spacing plates are each disposed within the working chamber, but three or more spacing plates may be disposed as appropriate.

〔Effect of the invention〕

The viscous coupling of the present invention has a configuration in which at least one of the first and second plate sets is non-rotationally engaged with each transmission member in only one direction.

That is, since the engagement means having a so-called one-way clutch function that can change the torque transmission characteristics depending on the direction of relative rotation is disposed between the transmission member and the plate assembly, the diameter of the rotational torque transmission portion of the one-way clutch can be changed. can be increased, and the torque transmission capacity of the viscous coupling can be increased.

Therefore, it was possible to provide a compact viscous coupling with a one-way clutch function that has a large torque transmission capacity.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a viscous coupling according to the first embodiment of the present invention, FIG. 2 is an enlarged view of the main part of the viscous coupling shown in FIG. 1, and FIGS. 3 and 4 are the same as those shown in FIG. A front view of the inner plate and spacing plate shown in
5 and 6 are front sectional views of essential parts of this embodiment showing different states, FIG. 7 is a sectional view of a viscous coupling based on the second embodiment of the present invention, and FIG.
Figures 9 and 10 are front views of the outer plate and spacing plate shown in Figure 7, and Figures 11 and 12 show different states of the viscous coupling. A front sectional view of main parts of this embodiment shown,
FIG. 13 is a sectional view of a viscous coupling based on the third embodiment of the present invention, FIG. 14 is an enlarged view of the main part of the viscous coupling shown in FIG. 13, and FIG. 15 is a cross-sectional view of each embodiment 11i.
FIG. 2 is a skeleton mechanism diagram showing a power system of a vehicle using a viscous coupling based on #A. (Symbols in the diagram) 1...Engine 3...Transmission 5...Front differential 7.9...Front axle 11
．． 13... Front wheel 15... Direction conversion gear set 17... Transfer 18.19.79... Viscous coupling 20.3
3.97...Housing (first transmission member) 21...
・Propeller shaft 22.35.81...Hub (second transmission member) 23・
...Rear differential 24.65.93...Roller 25.27...Rear axle 26...Retaining ring 2B
, 30,47.49-X'177g29.31...
Rear wheel 32.37.41...Spline 34.55,100...Outer plate (first plate) 36, 57.85.99...Inner plate (second plate 3B, 56,103... ... Spacing plate 39 ... Output shaft 40, 45.8
3... Working chamber 42.67.87... One-way clutch 43... Connection shaft 44.59, 101... Spline engagement means 46.6
1.102...Spacer ring 48...Bearing 50...Washer 51.53...Backup ring 52...Retaining ring 54...Lock nut 58...Bolt 6 60...Bearing 6
2... Seal 63.66... Notch 64.68
...Holding part 69...Washer 73.84.
・・Narrow place 77.82・・Wide place 89・・
・First plate group 91...second plate group 95
...Retaining ring (Fig. 1, 4t) j4, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 9, Fig. 10, Fig. 11, Fig. 12

Claims (1)

[Claims] first and second transmission members arranged so as to be relatively rotatable;
a working chamber in which a viscous fluid is sealed; a first plate set engaged with a first transmission member; and a second transmission member arranged alternately with the first plate set in the working chamber; a viscous coupling having an engaged second plate set, the engaging portion of at least one of the first and second plate sets having notches formed at equal intervals in the circumferential direction; and an engaging means non-rotationally engaged only in one direction, comprising an engaging element passing through the notch of each plate in the axial direction, and a spacing plate for holding the engaging element at equal intervals. A viscous coupling characterized by: