JP2002039228A - Clutch device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a clutch device to be excellent in responsiveness by starting a first rotary shaft in either of starting directions by small starting torque, in a clutch device. SOLUTION: A clutch device A comprises a ball cam mechanism 7 formed that when the first rotary shaft is rotated, a cam plate 4 is displaced to one in an axial direction, a taper cone surface 4a is separated away from a tapered cone surface 1a of a clutch housing 1, and three members of the first rotary shaft, the cam plate, and a second rotary shaft are integrally intercoupled; and when the second rotary shaft is rotated, two tapered cone surfaces are forced into pressure contact with each other and three members of the second rotary shaft, the cam plate, and the clutch housing are formed integrally with each other and the second rotary shaft is brought into a non-rotation state. In a cam groove 8 of the first rotary shaft of the ball cam mechanism, the inclination angle of the cam surface on the other side is set to a value higher than that of a cam surface on one side so that when deceleration torque in a direction in which the first rotary shaft is decelerated is applied, a ball is prevented from rolling from a cam surface 8a1 on one side to a cam surface 8a2 on the other side after exceeding a neutral position 8a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a clutch device. This clutch device is interposed between two first and second rotating bodies arranged coaxially and synchronizes the two rotating bodies when rotational power is input to the first rotating body. When the rotational power is input to the second rotating body, both the rotating bodies are switched to a non-rotatable state.

[0002]

2. Description of the Related Art The applicant of the present invention has proposed a clutch device which is not known but is shown in FIGS. FIG.
FIGS. 6A to 6C are longitudinal sectional views of the clutch device, and FIGS. 6A to 6C are sectional views of main parts of the ball cam mechanism shown in FIG.

In the conventional clutch device B shown in these figures, 1 is a clutch housing, and 2 is a first clutch device.
Rotation axis, 3 is the second rotation axis, 4 is the cam plate, 5
Denotes a spring, 6 denotes a rolling bearing, and 7 denotes a ball cam mechanism.

A ball cam mechanism 7 includes circumferential cam grooves 8 and 9 provided on both opposing surfaces of the first rotary shaft 2 and the cam plate 4, and a ball 1 interposed between the cam grooves 8 and 9.
0 is included.

In both cam grooves 8, 9, 8a, 9a are:
The deepest neutral position at the center in the circumferential direction, 8a1, 8a2; 9a1,
9a2 is a cam surface whose depth is shallow in both circumferential directions as viewed from the neutral position.

As the first rotating shaft 2 rotates in either the forward or reverse direction, the ball 10 moves from the neutral position in FIG.
By rolling to the position shown in FIG. 6B or FIG. 6C, the cam plate 4 is displaced to one side in the axial direction and the tapered cone surface 4a
Is separated from the tapered cone surface 1a of the clutch housing 1, and the first rotating shaft 2, the cam plate 4, and the second rotating shaft 3 are integrated, and the rotating shafts 2 and 3 rotate synchronously to generate power. Is transmitted.

When the second rotating shaft 3 rotates, the ball 10
6 (a) from the position of FIG. 6 (b) or FIG. 6 (c).
, The cam plate 4 coupled to the second rotating shaft 3 so as to be synchronously rotatable is displaced in the other axial direction, and the tapered cone surface 4 a is pressed against the tapered cone surface 1 a to contact the second rotating shaft 3. The three members of the cam plate 4 and the clutch housing 1 are integrated, and the second rotating shaft 3 is brought into a non-rotating state, whereby power transmission is cut off.

In the case of such a clutch device, the cam surfaces of both cam grooves 8, 9 have the same inclination angle.

[0009]

In the case of the conventional clutch device, since the inclination angles of the cam surfaces of the two cam grooves 8 and 9 are the same, the first rotating shaft 2 is started by a driving source such as a motor. In order to transmit the rotational power to the second rotating shaft 3, the same starting torque is required in any starting direction. In this case, if the inclination angles of both cam surfaces are set to be large. In addition, the starting torque increases in any direction, and the response is low.

In the case of the conventional clutch device, when the power of a motor or the like for rotating the first rotating shaft 2 is cut off while the first rotating shaft 2 is transmitting power to the second rotating shaft 3, the first rotating shaft 2 is turned off. The cam plate 4 receives a deceleration torque for decelerating the rotation from the cam plate 4, while the cam plate 4 itself tries to continue the rotation with the inertia torque.

Then, the ball 10 located on one of the cam surfaces of the cam grooves 8, 9 rolls toward the neutral position of the cam grooves 8, 9, and the cam plate 4 is displaced in the other axial direction. Although the tapered cone surface 4a is pressed against the tapered cone surface 1a, in the case of the conventional clutch device, since the inclination angles of the cam surfaces of the two cam grooves 8, 9 are the same, the cam plate 4 further increases its inertia torque. The rotation continues, and after the cam grooves 8 and 9 exceed the neutral position, they roll in the other circumferential direction and roll on the other cam surface, and the cam plate 4 is again displaced in the axial direction and the tapered cone Surface 4a is spaced from tapered cone surface 1a. Since such pressure contact and separation are repeated as long as the inertia torque continues, the tapered cone surfaces 1a and 4a are easily worn.

Accordingly, the present invention provides a clutch device as described above in which the first rotating shaft can be started with a small starting torque in at least one of the starting directions, and a response can be made in that direction. It is a common problem to be solved to provide a clutch device excellent in performance.

Further, the present invention provides a clutch device as described above, wherein the ball restricts the rolling of the ball beyond the neutral position in the cam groove of the first rotating shaft by the inertia torque of the cam plate, so that the two tapered cone surfaces are formed. Another object of the present invention is to provide a clutch device which can eliminate the repeated phenomenon of pressure contact and separation, suppress the progress of the wear, and maintain the clutch performance for a long period of time.

[0014]

A clutch device according to the present invention is interposed between the power transmissions of two rotating bodies disposed coaxially and facing each other, and rotational power is input to a first rotating body. When the rotation is performed, the two rotators are connected so as to be synchronously rotatable, while when rotational power is input to the second rotator, the second rotator is brought into a non-rotation state and separated from the first rotator. A movable friction member, which is axially opposed to the first rotating body, is rotatable synchronously with the second rotating body, and is mounted so as to be axially displaceable; A fixed friction member fixedly disposed at a position where the dynamic friction member is pressed or separated, and a first rotating body, a movable friction member, and a second rotating body which separate the movable friction member from the fixed friction member when the first rotating body rotates. Both rotating bodies with the body and the three Synchronously while rotatably coupled,
When the second rotator rotates, the movable friction member is pressed against the fixed friction member to integrate the second rotator, the movable friction member, and the fixed friction member into a non-rotating state. A cam mechanism, wherein the cam mechanism is provided with a circumferential cam groove provided on each of both opposing surfaces of the first rotating body and the movable friction member, and the movable friction member is fixed by rolling in the both cam grooves in the circumferential direction. A rolling element that is displaced so as to be pressed against or separated from the friction member, wherein the cam groove of the first rotating body has a cam surface whose depth is shallow on both sides in the circumferential direction across the deepest neutral position, The inclination angles of both cam surfaces are set differently.

According to the present invention, the rolling element rolls on one cam surface by decreasing the inclination angle of both cam surfaces by decreasing the inclination angle of one cam surface and increasing the inclination angle of the other cam surface. When the rotation torque is applied from the first rotating body in the direction,
In a driving source such as a motor, the first rotating body can be started with a small rotating torque, and at the time of starting, the first rotating body can be smoothly rotated with a small starting torque to transmit rotational power to the second rotating body side. Accordingly, it is possible to provide a clutch device having excellent responsiveness.

According to a preferred embodiment of the present invention, when a deceleration torque for decelerating the first rotating body is applied from the movable friction member side, the rolling element is moved from the one side cam surface to the other side cam beyond the neutral position. The inclination angle of the other cam surface is set larger than the inclination angle of the one cam surface so as not to roll the surface.

In this embodiment, the rolling of the rolling element beyond the neutral position in the cam groove of the first rotating element is restricted by the inertia torque of the movable friction member. It is possible to provide a clutch device in which the phenomenon is eliminated, the progress of the wear is suppressed, and the clutch performance can be maintained for a long time.

Japanese Patent Application Laid-Open No. H11-254,891 discloses a clutch device in which the cam surfaces contacting the rolling elements have different inclination angles. In the case of the ball cam mechanism in the clutch device disclosed in this publication, although the inclination angle of the cam surface is different, the rolling element can roll with respect to the cam surface in any direction, and the inclination angle of the cam surface The difference is that the rolling element is rolled on a cam surface with a small inclination angle, one output gear is rolled on one side, and the cam surface with a large inclination angle is rolled on the other side to displace the other output gear on the other side. This is different from the ball cam mechanism of the present invention.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below based on embodiments shown in the drawings.

A clutch device according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a side sectional view of the clutch device in a power cutoff state, and FIG.
FIG. 3 is a side sectional view of the clutch device in a power transmission state.
FIG. 4A is an exploded perspective view of a main part of the clutch device, and FIG.
FIG. 4B is an enlarged cross-sectional view of a main part of the first rotating shaft and the cam plate of the cam plate in FIG. 1 when viewed from the side. FIG. It is the principal part enlarged sectional view which was.

In these figures, A indicates the entire clutch device. The clutch device A includes a clutch housing 1, a first rotating shaft 2, a second rotating shaft 3, a cam plate 4, Conical coil spring 5 and rolling bearing 6
And a ball cam mechanism 7.

The clutch housing 1 is fixed to a clutch device mounting wall (not shown) as a fixed friction member, and has a cylindrical structure having a conical tapered cone surface 1a and a bearing mounting surface 1b.

The first rotating shaft 2 is formed as a first rotating body in the shape of a bottomed cylinder and is driven to rotate by a power source such as a motor. An annular flange 2a extending outward in the radial direction is integrally formed, and a through hole 2d having a diameter smaller than the inner diameter of the cylindrical portion 2c is provided at the center of the bottom wall 2b.

The second rotating shaft 3 is inserted as a second rotating body so that one axial shaft portion 3a extends outside the clutch housing 1 and is rotatable relative to a through hole 2d of the first rotating shaft 2. A convex shaft portion 3b is provided.

The second rotating shaft 3 has spline teeth 3c formed on the outer peripheral surface thereof, and is rotatably supported on a bearing mounting surface 1b of the clutch housing 1 via a rolling bearing 6. In this case, the retaining ring 3e is fixed to the circumferential groove 3d on the outer peripheral surface of the second rotating shaft 3, thereby preventing the second rotating shaft 3 and the like from falling out of the clutch housing 1.

The cam plate 4 serves as a movable friction member.
The outer peripheral surface has a conical tapered cone surface 4a, and has an annular plate structure concentrically arranged with the clutch housing 1 so as to face the tapered cone surface 1a of the clutch housing 1.

The cam plate 4 also has a fitting hole for the second rotating shaft 3, and has spline teeth 4 b fitted on the inner peripheral wall of the fitting hole with the spline teeth 3 c of the second rotating shaft 3. 3c, it can rotate synchronously with the second rotating shaft 3 and can be displaced in the axial direction.

The rolling bearing 6 is constituted by a single row deep groove ball bearing.

Next, the ball cam mechanism 7, which is a feature of the present embodiment, will be described.

The ball cam mechanism 7 includes a radially outward flange 2 a of the first rotating shaft 2, a cam plate 4, a conical coil spring 5, and a ball 10 as constituent elements.

The cam plate 4 is coaxially opposed to the flange 2a of the first rotating shaft 2 so as to be axially displaceable.

A pair of cam grooves 8 and 9 are separately provided on opposing surfaces of the flange 2a and the cam plate 4.

Each of the two cam grooves 8, 9 is formed on a cam surface 8a1, 8a2; 9a1, 9a2 whose depth becomes shallower from the deepest neutral position 8a, 9a toward both sides in the circumferential direction.

The conical coil spring 5 is a resilient biasing member for resiliently biasing the cam plate 4 toward the flange 2a.

The ball 10 has two cam grooves 8,
It is stored so as to be able to roll between nine.

In such a ball cam mechanism 7, the inclination angles of the cam surfaces 8a1 and 8a2 on both sides in the circumferential direction from the neutral position 8a in the cam groove 8 of the first rotary shaft 2 correspond to the rotational torque from a drive source such as a motor. From the neutral position 8a on both sides in the circumferential direction.

The inclination angle of the other cam surface 8a2 is
When a deceleration torque is applied from the cam plate 4 side to decelerate the first rotary shaft 2, the ball 10 is moved from one side cam surface 8 a 1 beyond the neutral position to the other side cam surface 8 a.
2, the other cam surface 8a2 is set to have a larger inclination angle than the one cam surface 8a1.

Similarly, for the cam groove 9 of the cam plate 4, the inclination angles of the cam surfaces 9a1 and 9a2 on both sides in the circumferential direction from the neutral position 9a in the cam groove 9 of the cam plate 4 are the same on both sides in the circumferential direction from the neutral position 9a. They are set differently. Specifically, the inclination angle of the other cam surface 9a2 is set to be larger than the inclination angle of the one cam surface 9a1.

The two cam grooves 8, 9 are located at the neutral position 8a,
The depth is set at 9a, which is smaller than the radius of the ball 10.

With the above configuration, in the ball cam mechanism 7,
With the rotation of the first rotating shaft 2, the ball 10 is moved into
The cam plate 4 is positioned close to the flange 2a by being located at the neutral position 8a, 9a, and the cam plate 4 is positioned at the one-side cam surface 8a1, 9a1 of the cam groove 8, 9 by the flange 2a. While being separated from the side, the cam grooves 8 and 9 cannot roll over the neutral positions 8a and 9a to the other cam surfaces 8a2 and 9a2.

Next, the operation of the clutch device A will be described.

The cam plate 4 is urged in the other axial direction by a conical coil spring 5, and when the tapered cone surface 4 a is pressed against the tapered cone surface 1 a of the clutch housing 1, the second rotating shaft 3 rotates The rotation has been locked and it is in a non-rotation state. In this state, as shown in FIG. 4 (a), the ball 10 is in the neutral position 8a,
9a.

In this state, when the first rotary shaft 2 is driven to rotate by a power source such as a motor (not shown), the ball 10 moves in the neutral positions 8a, 8a in FIG. 9a
Then, the one side cam surfaces 8a1 and 9a1 roll as shown in FIG. 4 (b).

As a result, the cam plate 4 is displaced in the axial direction from the flange 2a against the conical coil spring 5, and the tapered cone surface 4 of the cam plate 4 is displaced.
a is separated from the tapered cone surface 1 a of the clutch housing 1, and the first rotating shaft 2, the cam plate 4, and the second rotating shaft 3
Are rotated together as a unit, and the rotational power is transmitted from the first rotating shaft 2 to the second rotating shaft 3.

Next, when the power of the power source such as a motor is cut off and the rotational power to the first rotary shaft 2 is lost, a deceleration torque for reducing the rotation is applied to the first rotary shaft 2 from the cam plate 4. , The cam plate 4 itself tries to continue rotation by inertia torque.

Then, as shown in FIG. 4B, the balls 10 located on the one-side cam surfaces 8a1 and 9a1 of the cam grooves 8 and 9 correspond to the cam grooves 8 and 9 shown in FIG. Rolls toward the neutral positions 8a and 9a, whereby the cam plate 4 is displaced in the other axial direction, and the tapered cone surface 4a is pressed against the tapered cone surface 1a.

In the case of the clutch device A of the embodiment, even if the cam plate 4 continues to rotate further with its inertia torque, the other cam surface 8 of the cam grooves 8 and 9 will not rotate.
Since the inclination angles of a2 and 9a2 are set to a size that restricts the rolling of the ball 10, the ball 10 moves beyond the neutral positions 8a and 9a of the cam grooves 8 and 9 and the other cam surface 8a
It cannot roll to 2,9a2.

As a result, the cam plate 4 is not displaced in the axial direction again, unlike the conventional case, and the tapered cone surfaces 1a and 4a are not repeatedly pressed and separated by the inertia torque of the cam plate 4, Wear of the tapered cone surfaces 1a, 4a is suppressed.

The clutch device of the present invention is, for example,
The present invention can be applied to a continuously variable transmission, an electric power steering, and other mechanical devices.

[0050]

As described above, according to the present invention, the cam groove of the first rotating body has a cam surface with a shallow depth on both sides in the circumferential direction with respect to the deepest neutral position. Since the inclination angles are set differently, for example, by reducing the inclination angle of one cam surface and increasing the inclination angle of the other cam surface, the direction in which the rolling element rolls on one cam surface When the rotation torque is applied from the first rotating body, the driving power source such as a motor can start the first rotating body with a small rotating torque and transmit the rotating power to the second rotating body, so that the responsiveness is excellent. A clutch device can be provided.

In the case where a clutch device with a different starting torque is required, the present invention uses a cam surface with a large inclination angle and a small starting torque in a clutch device with a large starting torque. By using a cam surface having a small inclination angle in a clutch device having a required specification, a single clutch device can be used for both types of clutch devices, which is convenient.

Further, in the case of the present invention, when a deceleration torque for decelerating the first rotary body is applied from the movable friction member side, the rolling element is moved from one cam surface to a neutral position beyond the neutral position. When the inclination angle of the other cam surface is set to be larger than the inclination angle of the one cam surface so that the rolling member does not roll, the rolling member moves the neutral position in the cam groove of the first rotating member by the inertia torque of the movable friction member. Since over rolling is restricted, it is possible to provide a clutch device that eliminates the repetitive phenomenon of press-contact and separation of both tapered cone surfaces, suppresses the progress of wear of the tapered cone surfaces, and can maintain clutch performance for a long period of time. .

[Brief description of the drawings]

FIG. 1 is a side sectional view of a clutch device according to an embodiment of the present invention in a power non-transmission state.

FIG. 2 is a side sectional view of the clutch device according to the embodiment of the present invention in a power transmission state.

FIG. 3 is a perspective view of a main part of FIG. 1;

4A is an enlarged cross-sectional view of a main part of the first rotary shaft and the cam groove of the cam plate in FIG. 1 viewed from the side, and FIG.
Main part enlarged sectional view of both cam grooves of rotating shaft and cam plate viewed from the side.

FIG. 5 is a side sectional view of a conventional clutch device in a power non-transmission state.

6A is an enlarged cross-sectional view of a main part of the first rotating shaft and the cam groove of the cam plate in FIG. 1 when viewed from the side, and FIGS.
2 is an enlarged cross-sectional view of a main part of the cam groove of the first rotation shaft and the cam plate viewed from the side corresponding to the rotation direction of the first rotation shaft in FIG.

[Explanation of symbols]

 Reference Signs List 1 clutch housing 1a taper cone surface 2 first rotation shaft 3 second rotation shaft 4 cam plate 4a taper cone surface 5 conical coil spring 7 ball cam mechanism 8 cam groove 8a neutral position of cam groove 8 8a1, 8a2 cam surface of cam groove 8 9 cam Groove 9a Neutral position 9a1, 9a2 of cam groove 9 Cam surface of cam groove 9

Claims (2)

[Claims] An intervening power transmission between two rotating bodies arranged coaxially and capable of rotating both rotating bodies synchronously when rotating power is input to a first rotating body. A clutch device that, when rotational power is input to the second rotating body, causes the second rotating body to be in a non-rotating state and separates from the first rotating body. While being arranged opposite,
A movable friction member which is rotatable synchronously with the second rotating body and is attached so as to be axially displaceable; a fixed friction member fixedly arranged at a position where the movable friction member is pressed or separated by the axial displacement of the movable friction member; When the first rotator rotates, the movable friction member is separated from the fixed friction member, and the first rotator, the movable friction member, and the second rotator are integrated into a unit so that the two rotators can be synchronously rotated. On the other hand, when the second rotating body rotates, the movable friction member is pressed against the fixed friction member, and the second rotating body, the movable friction member, and the fixed friction member are integrated to rotate the second rotating body without rotation. And a cam mechanism provided on both opposing surfaces of the first rotating body and the movable friction member, and the cam mechanism is capable of rolling in the two cam grooves in the circumferential direction. Press the dynamic friction member against the fixed friction member And a rolling element that is displaced so as to be spaced apart from each other. In the cam groove of the first rotating body, a cam surface whose depth is shallower on both sides in the circumferential direction with respect to the deepest neutral position, and an inclination angle of the two cam surfaces Are set differently from each other. 2. The clutch device according to claim 1, wherein the rolling element is positioned beyond a neutral position from one cam surface where the rolling element is positioned when a deceleration torque in a direction for decelerating the first rotary body is applied from the movable friction member side. Do not roll the side cam surface
A clutch device, wherein an inclination angle of the other cam surface is set to be larger than an inclination angle of the one cam surface.