JP2001153203A - Cam groove, coupling using it and differential gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the machining cost for a cam face and to reduce the cost by using a thrust bearing. SOLUTION: This differential gear includes a support member 11 connected and disconnected to and from a torque transmitting member 3 by a clutch 9, a pressing member 15 connected to the torque transmitting member 5 and provided with the cam face 17, and a rolling element 13 supported on the member 11 in contact with the member 3 and engaged with the cam face 17, and when the member 11 is connected to the member 3 by the clutch 9, on receiving torque between the members 3, 5, the member 15 is operated to move by thrust force generated in the cam face 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cam mechanism and a coupling and differential device using the same.

[0002]

2. Description of the Related Art The structure of a conventional coupling is as follows.
"New Gaia Manual 0-22 pages, edited by Toyota Motor Co., Ltd., published by the Service Department, May 1998
On day 29, a coupling 301 as shown in FIG. 9 is described.

[0003] The coupling 301 is arranged in a rear wheel-side power transmission system of a four-wheel drive vehicle.
Hub 305, multi-plate main clutch 307 and pilot clutch 309, armature 311, electromagnet 31
3, cam ring 315, ball cam 317, pressing member 3
19, a controller and the like.

[0004] The rotary case 303 is connected from the transfer to the transmission via a propeller shaft. A drive pinion shaft 321 is spline-connected to the hub 305, and a drive pinion gear 323 formed integrally with the drive pinion shaft 321 is provided on a rear differential (differential device for distributing the driving force of the engine to the left and right rear wheels). It is in mesh with the ring gear.

[0005] The main clutch 307 includes a rotating case 303.
The pilot clutch 309 is disposed between the rotating case 303 and the cam ring 315.

The ball cam 317 is formed between the cam ring 315 and the pressing member 319.
Are splined to hub 305.

The controller excites the electromagnet 313, controls the excitation current, and stops the excitation.

When the electromagnet 313 is excited, the armature 311 is attracted and the pilot clutch 309 is pressed, and when the pilot clutch 309 is engaged, the torque between the rotating case 303 and the hub 305 is reduced by the ball cam 31.
7, the pressing member 31 is generated by the generated cam thrust force.
9, the main clutch 307 is pressed and engaged.

When the coupling 301 is connected in this way, the driving force of the engine is sent to the rear wheels, and the vehicle is driven in a four-wheel drive state, so that the running performance on rough roads and the stability of the vehicle body can be improved. .

When the exciting current of the electromagnet 313 is controlled, the slip of the pilot clutch 309 causes the ball cam 31 to slip.
7 changes, the coupling force of the main clutch 307 changes, and the driving force of the rear wheels is adjusted.

When the excitation of the electromagnet 313 is stopped, the pilot clutch 309 is released, the cam thrust force of the ball cam 317 disappears, the main clutch 307 is released, the connection of the coupling 301 is released, and the vehicle is brought into a two-wheel drive state. Become.

FIGS. 10 and 11 show a coupling 351 having a configuration similar to that of the coupling 301 described above.

[0013] The rotary case 353, the hub 355,
It is composed of a multi-plate main clutch 357 and a pilot clutch 359, an armature 361, an electromagnet 363, a cam ring 365, a ball cam 367, a pressing member 369, a controller, and the like. The electromagnet 363 sucks the armature 361 in the same manner as the coupling 301. When the pilot clutch 359 is engaged, the ball cam 367
Is actuated, and the main clutch 35
7 is fastened.

In the coupling 351, the rotating case 35
A thrust bearing 371 is disposed between the cam ring 3 and the cam ring 365 to prevent friction when they rotate relative to each other.

The cam ring 365 and the pressing member 369 include
As shown in FIG. 11, cam surfaces 373 and 375 are provided, respectively.
A ball 377 is arranged between 73 and 375.

Similarly, the cam surface of the ball cam 317 of the coupling 301 is provided on both the cam ring 315 and the pressing member 319, and the ball 3 is located between these cam surfaces.
25 are arranged.

[0017]

However, the conventional couplings 301 and 351 have the following problems.

(1) The processing of the cam surface requires many man-hours and requires high accuracy.
In No. 1,351, the cam surfaces are provided on both the cam rings 315, 365 and the pressing members 319, 369 constituting the ball cams 317, 367, so that the cost is extremely high.

(2) In addition, the coupling 351
In this case, the use of the thrust bearing 371 further increases the cost.

(3) Since a standard product is generally used for the thrust bearing 371, the thrust bearing 37
1 is subject to the following restrictions.

(A) Limited to the inner circumference of the thrust bearing 371, the inner diameter of the hub 379, the cam ring 365, and the pressing member 369 of the rotating case 353, and the outer diameter of the hub 355 cannot be increased. Is limited.

(B) The size of the coupling 351 is increased by the size of the thrust bearing 371, and the coupling 351 becomes heavier.

(C) Due to the large size of the coupling 351, a large arrangement space is required when the coupling 351 is mounted on a vehicle, so that the in-vehicle mountability is impaired and the degree of freedom in layout is limited.

Accordingly, the present invention provides a cam mechanism which reduces the machining cost of the cam surface and is free from the cost increase and limitation due to the thrust bearing, and a low cost, small size and light weight cup using the cam mechanism. It is intended to provide a ring and a differential device.

[0025]

According to a first aspect of the present invention, there is provided a cam mechanism comprising:
A support member that is connected and disconnected by a clutch with a torque transmission member on one side; a pressing member that is movably connected to the torque transmission member on the other side and that has a cam surface; and a support member that is formed on the support member. A rolling member that is rotatably supported by the supporting portion, one surface of which is in contact with the one-side torque transmitting member, and the other surface is engaged with the cam surface of the pressing member. When the clutch is connected to the one-side torque transmitting member by a clutch, a thrust force is generated on the cam surface by receiving a torque between the two torque transmitting members, and the pressing member is moved.

When the supporting member is connected to the one-side torque transmitting member by the clutch, the rolling element held on the supporting member (one-side torque transmitting member side) and the cam surface of the pressing member (other side torque transmitting member). Then, a torque is applied between the two torque transmitting members, and a thrust force is generated on the cam surface.

Since the rolling element has one surface in contact with the one-side torque transmitting member and cannot be moved, the pressing member retreats by receiving a thrust reaction force and is moved. The rolling elements roll on the cam surface at this time.

Therefore, when the coupling force of the clutch is controlled,
The cam thrust force changes due to the slip, and the moving operation force of the pressing member can be changed.

When the clutch is released and the supporting member is separated from the one-side torque transmitting member, the supporting member is in a free rotation state, and the supporting member (rolling element) and the pressing member (cam surface) rotate together while engaging. In this state, no torque is applied to the cam surface.

Thus, the cam thrust force disappears, and the operation of moving the pressing member is stopped.

The cam mechanism according to the first aspect operates as follows due to the above characteristics.

(1) Unlike the conventional example in which the cam surface is formed on two members, the cam surface is formed only on one member (pressing member). Since it has been reduced by half, the cost can be significantly reduced.

(2) Rotating case 353 and cam ring 36
Unlike the conventional coupling 351 in which the thrust bearing 371 is disposed between the thrust bearing and the fifth bearing, the thrust bearing is not used, so that the cost can be reduced accordingly.

(3) Further, since the thrust bearing is not used, (a) the restriction due to the inner circumference of the thrust bearing is released, and the inner diameter of the hub portion of the outer torque transmitting member, the supporting member, the pressing member, and the like, and the inner side. Outer diameter of the torque transmitting member
The diameter can be increased as necessary, and the degree of freedom in design can be improved.

For example, if the diameter of the inner torque transmitting member is increased, the strength is increased, so that a larger torque can be transmitted, and the durability is improved.

(B) The cam mechanism becomes compact by the size of the thrust bearing, and the weight can be reduced accordingly.

(C) Since the cam mechanism is compact and lightweight, the arrangement space for mounting on a vehicle can be narrowed accordingly, and the degree of freedom in layout can be improved.

According to a second aspect of the present invention, there is provided the cam mechanism according to the first aspect, further comprising a reducing means for reducing a surface pressure generated by being pressed by the rolling element, on a side of the torque transmitting member which comes into contact with the rolling element. Thus, the same effect as that of the first aspect can be obtained.

In addition to this, a one-side torque transmitting member to which a surface pressure is applied via each rolling element by a thrust reaction force of the cam, or a member such as a thrust washer disposed on the torque transmitting member is provided. By providing the reducing means for reducing the surface pressure, both the one-side torque transmitting member and the rolling element are protected, wear is prevented, and the durability of the device can be greatly improved.

According to a third aspect of the present invention, there is provided a cam mechanism according to any one of the first and second aspects, wherein the reducing means is a full circumferential groove engaged with each rolling element. Therefore, the same effects as those of the first and second aspects can be obtained.

In addition to this, in this configuration, a groove having a shape to be engaged with the rolling element is provided over the entire circumference on the torque transmitting member side in contact with the rolling element, so that the contact between the rolling element and the torque transmitting member side is provided. The contact area is increased, the surface pressure and wear are reduced, and the durability can be greatly improved.

According to a fourth aspect of the present invention, there is provided the cam mechanism according to any one of the first to third aspects, wherein the projection for preventing the rolling element from falling off is formed in the opening of the support portion formed in the support member. In this case, the same effects as those of the first to third aspects can be obtained.

In addition, by providing a projection at the opening (edge) formed in the support portion of the support member to prevent the rolling element from falling off, the rolling element is pre-assembled to the support member to form a subassembly. Is possible, the assembling work is made easier, and the cost is greatly reduced.

A cam mechanism according to a fifth aspect is the cam mechanism according to any one of the first to fourth aspects, wherein the rolling element is a ball. In addition to being able to obtain the same effect as the configuration, (1) the use of the ball as the rolling element makes it possible to reduce the cam mechanism compared to a configuration using a cylindrical or frustoconical rolling element that is long in the radial direction. As a result, the cam mechanism can be configured to have a smaller diameter, so that the on-boardability of a coupling or differential device using the cam mechanism can be improved as described below.

(2) According to the third aspect of the present invention, since the easily rollable and difficult-to-handle ball is engaged with the entire circumferential groove and positioned, the assembling of the cam mechanism becomes easy and the assembling cost is reduced. Can be.

(3) Further, according to the structure of the fourth aspect, the ball which is easy to roll and is difficult to handle can be sub-assembled to the support member, so that the assembling operation becomes easier and the cost is reduced.

The coupling according to claim 6 is the coupling according to claims 1 to 5
The cam mechanism according to any one of the above, a cylindrical torque transmitting member, an axial torque transmitting member that is relatively rotatably disposed inside the cylindrical torque transmitting member, and between the two torque transmitting members. It has a main clutch arranged, a pilot clutch intermittently operated by operating means, and one side and the other side of the torque transmitting member are cylindrical and axial torque transmitting members, respectively, and the clutch is a pilot clutch. When the support member is connected to the cylindrical torque transmitting member by the pilot clutch, a thrust force is generated on the cam surface by receiving the torque between the two torque transmitting members, and the main clutch is pressed and connected via the pressing member. It is characterized by that.

When the pilot clutch is connected, the cam mechanism operates by receiving the transmission torque applied to both torque transmitting members, and the main clutch (coupling) is connected by the generated thrust force.

For example, when this coupling is arranged in a rear-wheel-side power transmission system from a transfer to a rear differential of a four-wheel drive vehicle, when the coupling is connected, the driving force of the engine is sent to the rear wheels and the vehicle is driven. Becomes a four-wheel drive state, and can improve the running performance on rough roads and the stability of the vehicle body.

At this time, when the sliding of the pilot clutch is controlled by the operating means, the thrust force of the cam mechanism changes, and the coupling force of the main clutch (the transmission torque of the coupling: the driving force transmitted to the rear wheels) is adjusted. By controlling the driving force distribution ratio between the front and rear wheels in this way, it is possible to improve the controllability, stability, and the like of the vehicle during turning.

On the other hand, when the pilot clutch is released,
The support member enters a free rotation state, the thrust force of the cam mechanism disappears, the main clutch is released, the coupling is disconnected, and the vehicle enters a two-wheel drive state.

In addition to the above, the coupling according to the sixth aspect uses the cam mechanism according to any one of the first to fifth aspects, so that the coupling is configured at low cost and is compact and lightweight. In addition, the degree of freedom in terms of vehicle mounting and layout can be improved.

According to a seventh aspect of the present invention, there is provided a differential device, wherein the cam mechanism according to any one of the first to fifth aspects, a cylindrical torque transmitting member rotated by a driving force of an engine, and a rotation of the cylindrical torque transmitting member. Differential between the cylindrical torque transmitting member and one of the axial torque transmitting members or between the pair of axial torque transmitting members. And a pilot clutch that is intermittently operated by operating means, and one side and the other side of the torque transmission member are respectively cylindrical and axial torque transmission members or a pair of shaft transmissions. A torque transmitting member, wherein the clutch is a pilot clutch, and the supporting member is connected to one of the cylindrical torque transmitting member or one of the pair of axial torque transmitting members by the pilot clutch. That the thrust force is generated in the cam surface receives a differential torque between the torque transmission member, the main clutch is characterized in that the pressed connected via the pressing member.

For example, when the pilot clutch is connected, the cam mechanism is operated by receiving a differential torque between the cylindrical torque transmitting member and the shaft torque transmitting member, the main clutch is connected, and the differential mechanism is operated by the frictional resistance. Differential is limited.

At this time, when the slip of the pilot clutch is controlled by the operating means, the frictional resistance of the main clutch changes with the change of the thrust force of the cam mechanism, and the differential limiting force is adjusted.

On the other hand, when the main clutch is released, the main clutch is also released and the differential is allowed.

In addition to the above, the differential device according to the seventh aspect uses the cam mechanism according to any one of the first to fifth aspects, thereby being configured at low cost and being compact and lightweight. In addition, the degree of freedom in terms of vehicle mounting and layout can be improved.

[0058]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A coupling 1 (first embodiment of the present invention) will be described with reference to FIGS.

This coupling 1 has the features of the first, fifth and sixth aspects. FIG. 1 shows the coupling 1, and FIG. 8 shows a power system of a four-wheel drive vehicle using the coupling 1. The left and right directions are the left and right directions of the vehicle, and the right side in FIG. 1 corresponds to the front of the vehicle. In addition, members and the like without reference numerals are not shown.

As shown in FIG. 8, the power system includes a horizontally disposed engine 101, a transmission 103, a transfer 105, a front differential 107, and front axles 109 and 11.
1, left and right front wheels 113 and 115, a rear wheel side propeller shaft 117, a coupling 1, a rear differential 119, rear axles 121 and 123, left and right rear wheels 125 and 127, and the like.

As described above, the coupling 1 is disposed in the power transmission system on the rear wheel side.
5, 127 are connected and disconnected and the transmission torque is controlled.

The driving force of the engine 101 is transmitted from the output gear 129 of the transmission 103 to the differential case 133 of the front differential 107 via the ring gear 131, and from the front differential 107 via the front axles 109 and 111, the left and right front wheels 113 and 115. And transmitted to the coupling 1 via the differential case 133, the transfer 105, and the propeller shaft 117.

When the coupling 1 is connected, the driving force of the engine 101 is transmitted from the rear differential 119 to the rear axle 121,
Distributed to the left and right rear wheels 125, 127 via 123,
The vehicle enters the four-wheel drive state.

When the connection of the coupling 1 is released, the rear wheels below the rear differential 119 are disconnected, and the vehicle is brought into a two-wheel drive state.

As shown in FIG. 8, the rear differential 119 is accommodated in a differential carrier 135. This differential carrier 135
Is formed by connecting a casing body 137 and a front casing 139 with bolts 141.

The coupling 1 is housed on the front casing 139 side.

As shown in FIG. 1, the coupling 1 includes a rotating case 3 (a torque transmitting member on one side: a cylindrical torque transmitting member) and a hollow inner shaft 5 (a torque transmitting member on the other side: an axial torque transmitting member). ), Multi-plate main clutch 7,
Multi-plate pilot clutch 9 (clutch), cam plate 11 (supporting member), ball 13 (rolling member), pressure plate 15 (pressing member), cam surfaces 17, 17, armature 19, ring-shaped electromagnet 21 (operation means) , A cam mechanism 23, a controller and the like.

The cam mechanism 23 includes a rotating case 3, an inner shaft 5, a pilot clutch 9, and a cam plate 1.
1, a ball 13, cam surfaces 17, 17 and the like.

As shown in FIG. 1, the rotating case 3 includes a flange member 25, a cylindrical case 27, and a rotor 29. The flange member 25 is welded to the front side of the cylindrical case 27. In addition, the cylindrical case 27 and the rotor 29 are centered at the fitting portion 30 of each other, and are connected in the rotational direction by engaging the convex portion 31 of the rotor 29 with the cutout portion of the cylindrical case 27, so that the retaining ring 33 is formed. Are positioned in the axial direction.

The space between the cylindrical case 27 and the rotor 29 is O
A ring 35 is arranged.

A shaft 37 is formed on the flange member 25 of the rotating case 3. As shown in FIG. 8, the shaft portion 37 projects forward from the front cover 139 of the differential carrier 135, and a companion flange 145 is spline-connected to the spline portion 143.

This companion flange 145 is connected to the flange 149 on the joint 147 side, and connects the rotating case 3 to the propeller shaft 117 side.

The core 39 of the electromagnet 21 is fixed to the differential carrier 135 via a support member.

The flange member 25 of the rotating case 3 is supported on the differential carrier 135 by bearings on both sides seals, and the rotor 29 is supported on the differential carrier 135 via the bearings 41, the core 39 and the support members of both sides seals.

The inner shaft 5 penetrates the rotating case 3 from behind. The front end of the inner shaft 5 is supported by the flange member 25 via a ball bearing 43, and the rear end is supported by the rotor 29 via a needle bearing 45. An X-ring 47 having an X-shaped cross section is disposed between the inner shaft 5 and the rotor 29 to prevent oil leakage.

As shown in FIG. 8, the drive pinion shaft 1 is attached to the spline portion 49 of the inner shaft 5.
51 are connected. Drive pinion shaft 15
1, a drive pinion gear 153 is formed.
The drive pinion gear 153 meshes with the ring gear 155 on the rear differential 119 side to drive the rear differential 119 to rotate.

The differential carrier 135 is filled with lubricating oil for the rear differential 119, and lubricates the meshing portions between the drive pinion gear 153 and the ring gear 155, the supporting bearings thereof, and the sliding portions of each member.

The interior of the rotary case 3 is filled with oil from an oil supply channel 51, and after filling, the channel 51 is sealed by press-fitting a sealing ball 53.

A part of the inner periphery of the hollow inner shaft 5 forms a space 55 for increasing the internal capacity of the rotating case 3. The rotating case 3
As in the other parts, the filling oil and air are contained.

A piston 57 is arranged on the inner periphery of the inner shaft 5 in contact with the capacity increasing space 55, and the movement range is regulated by a retaining ring 59. Piston 5
An O-ring 61 is disposed between the inner shaft 7 and the inner shaft 5 to prevent oil leakage. Further, the piston 57 is pressed toward the retaining ring 59 by the coil spring 63.

The rotary case 3 has a closed casing formed by an O-ring 35 between the cylindrical case 27 and the rotor 29, an X-ring 47 between the inner shaft 5 and the rotor 29, and an O-ring 61 between the piston 57 and the inner shaft 5. Has been.

The pressing force of the coil spring 63 and the oil pressure of the capacity increasing space 55 are applied to the piston 57 from opposite directions, and the piston 57 is moved forward and backward by the fluctuation of the oil pressure and the bending of the coil spring 63 in accordance with the fluctuation. Moving. By the movement of the piston 57, the oil pressure inside the rotating case 3 is kept constant.

The oil sealed in the rotating case 3 is generally a special oil different from the oil sealed in the differential carrier 135.
Is sealed, so that the oil and the oil of the differential carrier 135 are not mixed.

The main clutch 7 is arranged between the inner circumference of the rotating case 3 and the outer circumference of the inner shaft 5.
A plate 65 and a washer 67 are arranged between the main clutch 7 and the flange member 25 to receive the pressing force of the main clutch 7 and the plate 65
The gap between the clutch plates is adjusted by exchanging with a different thickness.

The pilot clutch 9 is disposed between a spline portion 69 on the inner periphery of the rotating case 3 and a spline portion 71 on the outer periphery of the cam plate 11, and is attached to the rotor 29 of the rotating case 3 by the armature 19 as described later. Pressed and fastened.

As described above, the cam plate 11 and the ball 13 constitute a part of the cam mechanism 23. As shown in FIG. 2, the cam plate 11 has a large number of support holes 73 (support portions).
Are formed at equal intervals in the circumferential direction. In each support hole 73,
As shown in FIGS. 1 and 3, a ball 13 is arranged and supported so as to roll freely.

The pressure plate 15 is connected to a spline 75 for the main clutch 7 provided on the outer periphery of the inner shaft 5 so as to be movable in the axial direction.

As shown in FIGS. 1 and 3, the cam surfaces 17, 17 are radial and are formed at a plurality of positions on the pressure plate 15 at equal intervals in the circumferential direction. The balls 13 are engaged with the cam surfaces 17, 17, and the other side of each ball 13 is in contact with the rotor 29.

As shown in FIG. 3, the cam angle of each cam surface 17 is the same in both rotation directions of the coupling 1, and generates the same cam thrust force when the vehicle is traveling forward and when traveling backward.

The armature 19 has a disk shape, and is provided between the pilot clutch 9 and the pressure plate 15, and
It is arranged on the inner periphery of the cylindrical case 27 so as to be movable in the axial direction. The position of the armature 19 is regulated by a snap ring or the like so that the armature 19 does not come into contact with the pressure plate 15 and is not too far from the pilot clutch 9.

As described above, the core 39 of the electromagnet 21
The portion fixed to the differential carrier 135 and accommodating the coil 77 penetrates into a concave portion 79 provided in the rotor 29 to form an air gap 81.

The lead wire 83 of the electromagnet 21 is drawn out of the differential carrier 135 via a grommet and connected to a vehicle-mounted battery.

The controller detects the turning traveling based on the vehicle speed, the steering angle, the lateral G, and the like, or performs the excitation of the electromagnet 21, the control of the excitation current, the stop of the excitation, and the like according to the road surface condition.

When the electromagnet 21 is excited, a magnetic loop is formed, the armature 19 is attracted, and the rotating case 3
The pilot clutch 9 is pressed and fastened between the rotor 29 and the other rotor 29.

When the pilot clutch 9 is engaged, the cam plate 11 is connected to the rotating case 3, and the ball 13 held on the cam plate 11 and the cam surfaces 17, 17 of the pressure plate 15 are connected to the rotating case 3 and the inner case. A torque is applied between the shafts 5, and the cam mechanism 23 operates to generate a cam thrust force.

Since each of the balls 13 cannot move because one surface thereof is in contact with the rotor 29, the pressure plate 15 is retracted by receiving the thrust reaction force of the cam and presses the main clutch 7 to be engaged. At this time, the ball 13 rolls on the cam surfaces 17 and 17.

When the coupling 1 is connected in this way,
The driving force of the engine 101 is sent to the rear wheels 125 and 127, and the vehicle enters a four-wheel drive state, so that it is possible to improve running performance on rough roads and the stability of the vehicle body.

At this time, when the exciting current of the electromagnet 21 is controlled, the pilot clutch 9 slips, the rotation of the cam plate 11 is allowed, the torque applied to the cam surfaces 17, 17 changes, and the cam thrust force of the cam mechanism 23 decreases. As a result, the coupling force of the main clutch 7 changes, and the rear wheels 125, 1
27 is adjusted.

By controlling the driving force distribution ratio between the front and rear wheels in this way, for example, the steering and stability of the vehicle during turning can be improved.

When the excitation of the electromagnet 21 is stopped, the pilot clutch 9 is released, the cam plate 11 is in a free rotation state, and the engagement of the cam surfaces 17, 17 with the ball 13 causes the cam plate 11 and the pressure plate 15 to rotate.
Rotate integrally, and no torque is applied to the cam surfaces 17, 17.

Thus, the cam thrust force of the cam mechanism 23 disappears, the moving operation of the pressure plate 15 is stopped, the main clutch 7 is released, the connection of the coupling 1 is released, and the vehicle enters a two-wheel drive state.

Openings 83 and bridge portions are formed alternately in the circumferential direction on each clutch plate of the pilot clutch 9.
Magnetic leakage from the magnetic force loop is prevented, and the magnetic force of the electromagnet 21 is concentrated on the armature 19.

The rotor 29 is divided into an outer peripheral side and an inner peripheral side by a ring 85 of stainless steel (nonmagnetic material). The ring 85 prevents the magnetic force of the electromagnet 21 from being short-circuited and concentrates the magnetic force on the armature 19.

The pressure plate 15 is provided with a through hole 87 so as to reduce the resistance of the oil received by the pressure plate 15 to improve the pressing response of the main clutch 7 and to improve the pressure response of the main clutch 7 and the pilot clutch 9. This facilitates the movement of the oil between them, improving their lubricity and cooling performance.

The oil sealed in the rotating case circulates inside due to the centrifugal force of the coupling 1 and contacts the ball 13 of the cam mechanism 23 with the cam surfaces 17, 17 and the rotor 29; the ball bearing 43; Clutch 7,
It is supplied to a sliding surface between the inner circumference of the pilot clutch 9 and the cam plate 11 and the outer circumference of the inner shaft 5 and the like to lubricate and cool them.

Thus, the coupling 1 is configured.

The coupling 1 has the following effects by using the cam mechanism 23.

(1) Unlike the conventional example in which the cam surface is formed on two members, the cam mechanism 23 has the cam surface 17 formed only on the pressure plate 15 and halves the cam surface which requires a high processing cost. The cost of the cam mechanism 23 and the coupling 1 using the same can be greatly reduced.

(2) Since the thrust bearing 371 used in the conventional coupling 351 is not used, the cost can be further reduced.

(3) Since the thrust bearing is not used, (a) the restriction by the inner circumference of the thrust bearing is released, and the hub portion 89 of the rotor 29 of the rotating case 3, the cam plate 11, the pressure plate 15, etc. The inner diameter and the outer diameter of the inner shaft 5 can be increased as needed, and the degree of freedom in design can be improved.

For example, if the diameter of the inner shaft 5 is increased, the strength is increased, and a correspondingly large torque can be transmitted, and the durability can be improved.

(B) The cam mechanism 23 and the coupling 1
The size of the thrust bearing is reduced in size, and the weight can be reduced by the weight.

(C) The compact and lightweight design allows the coupling space for the coupling 1 to be narrowed accordingly, so that the vehicle mountability and the degree of freedom in layout can be greatly improved.

(4) Since the balls 13 are used as the rolling elements, the cam mechanism 23 and the cup mechanism are compared with the configuration in which, for example, a cylindrical or frustoconical rolling element long in the radial direction of the coupling 1 is used. Since the ring 1 is configured to have such a small diameter, the vehicle mountability of the coupling 1 can be further improved.

Further, the cam mechanism 23 includes the cam plate 1
The pilot clutch 9
Of the main clutch 7 due to the drag torque or unexpected vibration in the rotational direction can be suppressed, and the controllability of the transmission torque can be improved.

The coupling 1 may be arranged between the transfer 105 and the propeller shaft 117 as shown by the arrow 201 in FIG.

In this case, the coupling 1 is provided between the propeller shaft 117 and the rear differential 119 as shown in FIG.
As in the case of, the connection and disconnection of the rear wheels 125 and 127 and the control of the transmission torque are performed.

The coupling 1 is indicated by arrows 203 and 2
As indicated by the arrow 05, the front differential 107 may be disposed between the front wheels 113 and 115 on either side.
7, 209, it may be disposed between the rear differential 119 and either of the left and right rear wheels 125, 127.

When the couplings 1 are connected, the vehicle enters the four-wheel drive state when the couplings 1 are connected. When the connection is released, the differential rotation of the front differential 107 becomes free, and the front wheels 113, 205 The transmission of the driving force to 115 is stopped, and the vehicle enters the two-wheel drive state.

When the coupling 1 is connected, the vehicle is driven in a four-wheel drive mode when the coupling 1 is connected, and when the coupling is released, the differential rotation of the rear differential 119 becomes free, and the rear wheel is released. The transmission of the driving force to 125 and 127 is stopped, and the vehicle enters the two-wheel drive state.

In such a case, if the transfer 105 is provided with a clutch (2-4 switching mechanism) for interrupting the driving force, the propeller shaft 117 can be kept completely stationary, and noise and noise can be reduced. Vibration, wear and the like can be greatly reduced, and the fuel efficiency of the engine 101 can be improved.

Further, as shown by an arrow 211, the coupling 1 may be arranged in combination with a gear mechanism in the transfer 105. In this case, the coupling 1 is disposed between the propeller shaft 117 and the rear differential 119. In this case, the same function as in the case of No. 8 is obtained.

The coupling 1 is indicated by arrows 201 and 21.
1, the hub clutches 213, 215 are located between the rear axles 121, 123 and the rear wheels 125, 127.
Is disposed and the connection between them is released in conjunction with the coupling 1, the power transmission system from the coupling 1 to the rear wheels 125, 127 causes the rotation of the engine 101 and the rear wheels 125, 127,
127, the rotation stops, noise, vibration, wear, etc. are greatly reduced.
The fuel efficiency of the engine 101 can be improved.

FIG. 4 shows a coupling 91 which is a modification of the coupling 1 and in which the rotating case 93 is integrally formed, the ball 13 of the cam mechanism 23 and the rotating case 93 are shown. , A thrust washer 95 is disposed.

By disposing the thrust washer 95, it is necessary to use a material having a particularly high hardness for the rotating case 93 in order to prevent the rotating case 93 from being worn by contact with the ball 13. Need not be subjected to special heat treatment.

For the same reason, unlike the above-mentioned rotating case 3, it is not necessary to make the rotating case 93 a separate structure of the cylindrical portion and the wall portion.
Can be formed integrally to reduce the cost.

Next, the cam mechanism 171 will be described with reference to FIGS.
(2nd Embodiment of this invention) is demonstrated.

This cam mechanism 171 has the following features.
The coupling 1 has the features 3 and 5, and is used instead of the cam mechanism 23 in the coupling 1 described above. Less than,
The differences from the cam mechanism 23 will be described with reference to the members of the coupling 1.

The cam mechanism 171 includes a cam plate 11, a ball 13, a pressure plate 15, a cam surface 173,
73, peripheral grooves 175 (means for reducing surface pressure) and the like.

The cam surfaces 173 and 173 are formed at a plurality of positions on the pressure plate 15 at equal intervals in the circumferential direction.
The ball 13 is engaged with each of the cam surfaces 173 and 173.

The sectional shape of the cam surface 173 cut along a plane passing through the center of rotation of the coupling 1 is a part of an arc along the ball 13 as shown in FIG. Also, as shown in FIG.
The cam angle of the cam surface 173 is the same in both rotation directions of the coupling 1, and generates the same cam thrust force when the vehicle is traveling forward and when traveling backward.

The circumferential groove 175 is formed over the entire circumference of the rotor 29 with which the ball 13 contacts, and each ball 13 is engaged with the circumferential groove 175. Also, as shown in FIG.
A circumferential groove 17 cut on a plane passing through the center of rotation of the coupling 1
5 is a part of an arc along the ball 13.

As described above, by engaging each ball 13 with the circumferential groove 175, the contact area between the ball 13 and the rotor 29 is increased, and the cam thrust force generated on the cam surfaces 173, 173 causes each ball 13 and the rotor 29 to rotate. The surface pressure generated by the pressing of the second members 29 against each other is greatly reduced.

Thus, the cam mechanism 171 is constituted.

The cam mechanism 171 has the following features.
The following effects can be obtained.

(1) The surface pressure applied to the rotor 29 is
5, the wear of both the rotor 29 and the ball 13 is prevented, and the durability of the cam mechanism 171 and the coupling 1 can be greatly improved.

(2) Since the ball 13 that is easy to roll and is difficult to handle is positioned by the circumferential groove 175, the cam mechanism 17
1 is easy to assemble, and the assembling cost is reduced.

(3) The use of the ball 13 as the rolling element allows the cam mechanism 17 to be used in comparison with a configuration using a cylindrical or frustoconical rolling element that is long in the radial direction of the coupling 1, for example.
The coupling 1 and the coupling 1 can be configured to have such small diameters, and the mountability of the coupling 1 can be further improved.

[0139] A thrust washer may be arranged between the rotor 29 and the ball 13, and the circumferential groove 175 may be formed in this thrust washer.

In this case, (1) the rotating case is released from the contact pressure of the ball 13, and the degree of freedom in designing the material, heat treatment, divided structure or integrated structure is improved, and the cost is accordingly reduced. Can be.

(2) It is easier to process the circumferential groove 175 on the thrust washer than on the rotating case, and it is not necessary to process the circumferential groove 175 on the rotating case.

Next, the cam mechanism 181 (third embodiment of the present invention) will be described with reference to FIG.

This cam mechanism 181 has the following features.
The coupling 1 is used in place of the cam mechanism 23 in the coupling 1 described above. Hereinafter, differences from the cam mechanism 23 will be described with reference to the members of the coupling 1.

The cam plate 183 (support member) of the cam mechanism 181 has projections 187 formed at openings provided on both sides of the support hole 185 (support portion).

The projections 187 prevent the balls 3 supported by the support holes 185 from falling off.

Further, since the ball 3 is prevented from falling off,
The cam plate 183 and each ball 13 can be sub-assembled.

For subassembly of these, a convex portion 187 is formed in one opening of the cam plate 183 by caulking, the ball 13 is mounted in the support hole 185, and the other opening is caulked. A part 187 is formed.

Thus, the cam mechanism 181 is constituted.

As described above, since the cam mechanism 181 has the projections 187 and 187 provided in the support holes 185 of the cam plate 183, the cam plate 183 and each ball 13 can be sub-assembled. The attaching work becomes easier accordingly, and the cost can be significantly reduced.

The differential device according to the seventh aspect of the present invention has a low cost and is compact and lightweight by using the cam mechanism of the first to fifth aspects. The degree of freedom can be improved.

Further, in the above-described embodiment, an example in which a ball is used as a rolling element has been described. However, for example, a cylindrical or frusto-conical rolling element may be used.

The number of rolling elements supported by the support member can be determined arbitrarily.

[0153]

According to the first aspect of the present invention, the cam mechanism is constituted so as to operate only by the cam surface formed on the pressing member, and the cam surface having a high processing cost is reduced by half, so that the cost is greatly reduced. can do.

(2) Since the thrust bearing is not arranged between the rolling element and the torque transmitting member, the cost can be reduced accordingly.

(3) By not using the thrust bearing, (a) being released from the limitation by the thrust bearing, the inner diameter of the hub portion of the outer torque transmitting member, the supporting member, the pressing member, and the inner torque transmitting member. The degree of freedom in design with respect to the outer diameter and the like can be improved.

(B) The cam mechanism is reduced in size by the size of the thrust bearing, and the weight can be reduced accordingly.

(C) Since the cam mechanism is compact and lightweight, it is possible to improve the mountability and the degree of freedom in layout.

According to the cam mechanism of the second aspect, the same effect as that of the first aspect can be obtained, and the torque is reduced by the surface pressure reducing means provided on the torque transmitting member side to which the surface pressure from the rolling element is applied. Both the transmission member and the rolling elements are protected, wear is prevented, and the durability of the device can be greatly improved.

According to the third aspect of the present invention, the same effect as that of the first or second aspect can be obtained, and the cam mechanism is provided with a circumferential groove on the torque transmitting member side where the rolling element is engaged. Surface area and wear are reduced,
Durability can be greatly improved.

According to the cam mechanism of the fourth aspect, the same effect as the configuration of the first to third aspects can be obtained, and the projections for preventing the rolling elements from falling off are provided on the support member, so that the support member and the support member have the same structure. Sub-assembly with the rolling elements becomes possible, and the assembling work becomes easier accordingly, and the cost can be greatly reduced.

According to the fifth aspect of the present invention, the same effects as those of the first to fourth aspects can be obtained, and (1) the cam mechanism is configured to have a smaller diameter by using balls for the rolling elements. This makes it possible to improve the on-boardability of the coupling and the differential device using the cam mechanism.

(2) Since the ball which is easy to roll and is difficult to handle is engaged with the entire circumferential groove and positioned, the assembling of the cam mechanism becomes easy and the assembling cost can be reduced.

(3) Since a ball which is easy to roll and is difficult to handle can be subassembled to the support member, the assembling operation becomes easier and the cost can be reduced.

The coupling according to the sixth aspect is the first to fifth aspects.
By using the cam mechanism described above, it can be configured at low cost, can be compact and lightweight, and can improve the in-vehicle property and the degree of freedom in layout.

According to the seventh aspect of the present invention, by using the cam mechanism of the first to fifth aspects, the differential device is configured at a low cost, is compact and lightweight, and has improved in-vehicle mountability and layout flexibility. be able to.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first embodiment (a cam mechanism 23 and a coupling 1 using the same).

FIG. 2 is a plan view of a cam plate 11 used in the cam mechanism 23 of the first embodiment.

FIG. 3 is a sectional view taken along line AA of FIG. 1;

FIG. 4 is a cross-sectional view showing a modification of the first embodiment.

FIG. 5 is a sectional view showing a cam mechanism 171 according to a second embodiment.

FIG. 6 is a sectional view taken along line BB of FIG. 5;

FIG. 7 is a sectional view showing a cam plate 183 used in a cam mechanism 181 according to a third embodiment.

FIG. 8 is a skeleton mechanism diagram showing a power system of a four-wheel drive vehicle using the coupling 1 of FIG. 1;

FIG. 9 is a sectional view showing a first conventional example.

FIG. 10 is a sectional view showing a second conventional example.

11 is a sectional view taken along the line CC in FIG. 10;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Coupling 3 Rotation case (one side torque transmission member: cylindrical torque transmission member) 5 Inner shaft (other side torque transmission member: axial torque transmission member) 7 Main clutch 9 Pilot clutch 9 (clutch) 11,183 Cam plate (support member) 13 Ball (rolling member) 15 Pressure plate (pressing member) 17,173 Cam surface 21 Electromagnet (operating means) 23,171,181 Cam mechanism 73,185 Support hole (support portion) 175 Circumferential groove ( 187 Protrusion provided in support hole 185 of cam plate 183 to prevent ball 13 from falling off

Claims (7)

[Claims] A supporting member which is connected to and disconnected from the torque transmitting member on one side by a clutch; a pressing member movably connected to the torque transmitting member on the other side and formed with a cam surface; A rolling element that is rotatably supported by a support portion formed on the support member, has a surface on one side in contact with the torque transmission member on one side, and a surface on the other side engaged with a cam surface of the pressing member; A cam mechanism comprising: when a support member is connected to a one-side torque transmitting member by a clutch, a torque between the two torque transmitting members generates a thrust force on a cam surface to move a pressing member. 2. The cam mechanism according to claim 1, wherein a reduction means for reducing a surface pressure generated by being pressed by the rolling element is provided on a side of the torque transmitting member in contact with the rolling element. Cam mechanism. 3. The cam mechanism according to claim 1, wherein the reduction means is a circumferential groove engaged with each rolling element. 4. The cam mechanism according to claim 1, wherein an opening of a support portion formed in the support member is provided.
A cam mechanism comprising a projection for preventing a rolling element from falling off. 5. The cam mechanism according to claim 1, wherein the rolling element is a ball. 6. The cam mechanism according to claim 1, a cylindrical torque transmitting member, and an axial torque transmitting member disposed so as to be relatively rotatable inside the cylindrical torque transmitting member. And a main clutch disposed between the two torque transmitting members, and a pilot clutch intermittently operated by the operating means. One side and the other side of the torque transmitting member have cylindrical and axial torques, respectively. A transmission member, wherein the clutch is a pilot clutch, and when the supporting member is connected to the cylindrical torque transmission member by the pilot clutch, a thrust force is generated on the cam surface by receiving a torque between the two torque transmission members, and the pressing member is pressed. A coupling in which the main clutch is pressed and connected via the main clutch. 7. A cam mechanism according to claim 1, a cylindrical torque transmitting member which is rotated by a driving force of an engine, and a pair of shaft torques for rotating the cylindrical torque transmitting member. A differential mechanism distributed to the wheel side via the transmission member, and limiting the differential of the differential mechanism between the cylindrical torque transmission member and one of the axial torque transmission members or between the pair of axial torque transmission members. A main clutch and a pilot clutch which is intermittently operated by an operation means, and one side and the other side of the torque transmitting member are a cylindrical and an axial torque transmitting member or a pair of axial torque transmitting members, respectively. When the clutch is a pilot clutch and the supporting member is connected to one of the cylindrical torque transmitting member or one of the pair of axial torque transmitting members by the pilot clutch, a difference between the two torque transmitting members is obtained. Thrust force is generated in the cam surface under torque, a differential gear, wherein the main clutch is pressed connected via the pressing member.