JP2001165202A - Cam mechanism and clutch device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a ball interposed between cam grooves from slipped out therefrom by a simple structure. SOLUTION: This cam mechanism is provided with a first rotary shaft 2 and a cam plate 4 dividedly provided with the cam grooves 17, 18, the ball 19 between the cam grooves, and a Belleville spring 5 elastically energizing the cam plate 4; approaches the cam plate to the first rotary shaft side, when the both cam grooves are accorded with each other circumferentially in the relative rotation between the first rotary shaft and the cam plate; and separates the cam plate from the first rotary shaft side, when the cam grooves are deviated from each other circumferentially. The both cam grooves are thus formed into inclined faces gradually shallowed their depths towards the circumferential both sides, the depth of the most deep position is set to smaller than the radius of the ball, and the depth of the most shallow position is set to such a dimension as preventing the ball from slipped out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cam mechanism and a clutch device using the same.

[0002] This clutch device is interposed between the power transmissions of two rotating bodies disposed coaxially and opposed to each other, and is capable of rotating both rotating bodies synchronously when rotating power is input to a first rotating body. On the other hand, when rotational power is input to the second rotating body, the second rotating body is brought into a non-rotating state and separated from the first rotating body.

[0003]

2. Description of the Related Art In a conventional clutch device of this type,
When the first rotating body is driven to rotate by a power source such as a motor, and this rotating power is transmitted to the second rotating body,
When a rotational power is input to the second rotating body, the worm speed reducer or the electromagnetic brake is used as a mechanism for blocking the transmission of the rotating power to the first rotating body (reverse input) when the second rotating body is in a non-rotating state. Has been adopted.

In the case of the worm speed reducer, the transmission efficiency of the rotational power of the first rotating body to the second rotating body is low, and at the time of the transmission, the meshing noise between the worm gear and the worm is generated, and the quietness of the clutch device is reduced. Inferior.

[0005] In the case of an electromagnetic brake, electric power is required for the operation of the brake, so that the use cost increases, and in addition, a complicated electronic control circuit is required for controlling the energization of the electromagnetic coil for controlling the transmission timing of the rotational power, and the manufacturing cost is correspondingly increased. Will be higher.

[0006] In any case, there is a limit in reducing the weight of the clutch device.

Therefore, the applicant of the present application has determined that the first rotator has excellent transmission of rotational power and excellent quietness.
Japanese Patent Application No. 11-292099 (filed on Oct. 14, 1999) proposes a clutch device which has a simple structure, which can greatly reduce the cost in use and production, and can further reduce the weight. "Clutch device" has already been proposed.

[0008]

By the way, the cam mechanism in the clutch device according to the above-mentioned prior application is a fixed cam plate on which the first rotating shaft is arranged immovably in the axial direction, and the movable friction member is a fixed cam plate. The movable cam plate is coaxially opposed to the plate and supported so as to be slidable in the axial direction. A cam groove is formed on the opposing surface of the two cam plates, and a ball for clutch is rotatably interposed between the cam grooves of the two cam plates.

In the case of a clutch device having such a cam mechanism, even if the movable cam plate is urged in the direction of the fixed cam plate by a disc spring, rotational power is applied to the fixed cam plate and the circumferential direction of the two cam grooves is increased. When the ball rolls due to the displacement and the movable cam plate is separated from the drive side cam plate, the ball is likely to fall out of the cam groove.

The inventors of the present invention have made intensive studies on the prevention of the above-mentioned escape, and first considered providing a stopper having a special structure for pressing the movable cam plate in the axial direction. The structure not only complicates the structure of the clutch device but also increases the weight, and also increases the manufacturing cost of the clutch device.

Accordingly, the present invention has an object to solve the problem that it is possible to prevent a ball inserted between both cam grooves of a fixed cam plate and a movable cam plate from coming off with a simple structure in a cam mechanism. I have.

Another object of the present invention is to solve the problem that a clutch device having a cam mechanism can prevent a ball from coming off when transmitting rotational power and improve clutch performance without using a special stopper. Should be an issue to be addressed.

[0013]

A first cam mechanism according to the present invention comprises a pair of cam grooves which are coaxially arranged so that one of them is axially immovable and the other is axially displaceable. , A pair of fixed and movable cam plates provided separately, a ball rotatably housed between a pair of cam grooves of both cam plates, and an urging force for urging the movable cam plate toward the fixed cam plate. A slope having a depth decreasing toward at least one circumferential direction, and a slope having a depth decreasing toward at least the other direction in the other cam groove. The depth of the deepest position of each of the two cam grooves is set to be smaller than the radius of the ball, and the depth of the shallowest position of each of the two cam grooves prevents the ball from slipping out. Set to dimensions The ball is positioned at the deepest position of the two cam grooves with the relative rotation of the two cam plates, so that the movable cam plate is brought close to the fixed cam plate side, and the ball is positioned at the shallowest position of the two cam grooves. The position of the ball causes the movable cam plate to be separated from the fixed cam plate side.

A second cam mechanism according to the present invention comprises a pair of cam mechanisms, one of which is coaxially disposed so as to be stationary in the axial direction and the other in the axially displaceable state, and has a pair of cam grooves distributed on opposing surfaces thereof. A fixed and movable cam plate, a ball rotatably housed between a pair of cam grooves of both cam plates, and an urging member for elastically urging the movable cam plate toward the fixed cam plate side, Each of the two cam grooves is formed on a mortar-shaped slope whose depth decreases from the center in the circumferential direction to both sides in the circumferential direction, and the depth at the deepest position of each of the two cam grooves is smaller than the radius of the ball. Is set to
Further, the depth of the shallowest position of each of the two cam grooves is set to a dimension for preventing the ball from coming out, and when the two cam grooves are aligned in the circumferential direction with the relative rotation of the two cam plates. Then, the movable cam plate is brought closer to the fixed cam plate side, and when both cam grooves are shifted in the circumferential direction, the movable cam plate is separated from the fixed cam plate side.

According to the first and second cam mechanisms of the present invention, the depth at the deepest position of each of the two cam grooves is set to a dimension smaller than the radius of the ball, and the depth at the shallowest position is determined by the ball. By simply setting the dimensions to prevent the ball from slipping out, the ball can be prevented from slipping out, so that the configuration is simple and the manufacturing cost can be reduced.

According to a second preferred embodiment of the present invention, the dimensional relationship for preventing the ball from coming off in the cam groove is as follows:
The following expressions (1) to (3) are satisfied.

[0017] tanφ> (2 · T) / (Dp · Fs) and _{D B / 2> Ra ... (} 1) Dc> (S 1 / tanη) + D B · sinφ ... (2) S 2 <D B · cosφ -S ₁ ... (3) However, S _1: maximum axial displacement of the ball S _2: axial shortest distance between the fixed cam plate and the movable cam plate Dp: pitch circle diameter D _B of the ball: the ball diameter Dc : Cam groove circumferential outer diameter θ: cam operating angle φ: cam stopper angle η: inclination angle of mortar-shaped slope [(π-θ) / 2] T: rotational power Fs: spring force of biasing member Ra: corner R The clutch device of the present invention is interposed between the power transmissions of two rotating bodies disposed coaxially and opposed to each other, and enables both the rotating bodies to be synchronously rotated when the rotating power is input to the first rotating body. On the other hand, when the rotational power is input to the second rotating body, the second rotating body is A clutch device that is separated from the first rotating body in a rotating state, and is disposed so as to face the first rotating body in the axial direction, and is rotatable synchronously with the second rotating body and axially displaceable. A movable friction member,
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, and a first rotation by separating the movable friction member from the fixed member when the first rotating body rotates. The three members of the body, the movable friction member, and the second rotator are integrated and the two rotators are coupled so as to be synchronously rotatable. On the other hand, when the second rotator rotates, the movable friction member is pressed against the fixed friction member. A cam mechanism that integrates the three members of the second rotating body, the movable friction member, and the fixed friction member to bring the second rotating body into a non-rotating state, wherein the cam mechanism uses the first rotating body as a fixed cam plate. 4. The cam mechanism according to claim 1, wherein the movable friction member is used as a movable cam plate, and the movable friction member is displaced so as to be pressed against or separated from the fixed friction member by rolling of the cam mechanism ball. so That.

According to the clutch device of the present invention, the rotational power of the first rotating body can be transmitted to the second rotating body with high efficiency by the movable friction member, the fixed friction member, and the cam mechanism. The manufacturing cost can be reduced.

According to the clutch device of the present invention, the cam mechanism prevents the balls from climbing over the plate surfaces from the cam grooves of both cam plates when transmitting rotational power without a stopper, thereby improving clutch performance. At the same time, the weight and the structure can be simplified, and the manufacturing cost can be reduced.

[0020]

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

FIGS. 1 to 5 relate to a first embodiment of the present invention. FIG. 1 is a side sectional view of a clutch device in a power cutoff state, and FIG. 2 is a side sectional view of the clutch device in a power transmission state. 3 is an exploded perspective view of the clutch device, FIG. 4 (a) is an enlarged view of a main part of FIG. 1, and FIG. 4 (b) is an enlarged view of a main part of FIG. FIG. 5 is a view showing FIGS. 4A and 4B together. In FIG. 5, FIG. 4A is shown by a solid line, and FIG. 4B is shown by a virtual line.

In these figures, A indicates the entire clutch device. The clutch device A mainly includes a clutch housing 1, a first rotating shaft 2, a second rotating shaft 3, and a cam plate 4. , A disc spring 5, a rolling bearing 6, and a 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 tapered surface 1a which expands in one axial direction on one axial side of an inner peripheral surface thereof, It has a cylindrical structure having a bearing mounting surface 1b on the other side in the axial direction.

The first rotary shaft 2 is rotatably driven by a power source such as a motor. An annular flange 8 is integrally formed on the outer peripheral surface, and a small-diameter shaft portion 9 is formed on an axial end surface thereof. Is formed. The flange 9 may be formed separately from the rotary shaft main body 8.

The second rotating shaft 3 has an axially-bottomed hole 11 formed in the axial end surface of the other axial end of the first rotating body 2 with one axially extending axial portion 10 extending outside the clutch housing. The small-diameter shaft portion 9 is fitted and connected to the first rotating shaft 2 by the circlip 12.

The second rotating shaft 3 has spline teeth 13 formed on the outer peripheral surface thereof, and is rotatably supported on the bearing mounting surface 1 b of the clutch housing 1 via the bearing 6.

In this case, the circumferential groove 1 on the outer peripheral surface of the second rotating shaft 3
A retaining ring 15 is fixed to 4, 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 in the radial direction has a tapered surface 4a whose diameter increases toward one side in the axial direction, and has an annular plate structure arranged concentrically with the clutch housing 1 so as to face the tapered surface 1a of the clutch housing 1. I have.

The cam plate 4 also has a fitting hole for the second rotating shaft 3, and has spline teeth 16 fitted on the inner peripheral wall of the fitting hole with the spline teeth 13 of the second rotating shaft 3. And 16 are fitted together to rotate integrally with the second rotating shaft 3 and can be displaced in the axial direction.

The cam mechanism 7 includes at least the flange 8, the cam plate 4, the disc spring 5, and the ball 19 as constituent elements.

The flange 8 functions as a fixed cam plate that is immovable in the cam mechanism 7 in the axial direction.

The cam plate 4 is coaxially opposed to the flange 8 as a movable cam plate in the cam mechanism 7 so as to be axially displaceable.

A pair of cam grooves 17 and 18 are separately provided on opposing surfaces of the flange 8 and the cam plate 4.

Each of the cam grooves 17, 18 has a mortar-like slope 17a1, 17a2; 18a1, 1 whose depth decreases from the circumferential center 17a0, 18a0 toward both sides in the circumferential direction.
8a2.

The disc spring 5 connects the cam plate 4 to the flange 8
It becomes an urging member that urges toward the side.

The ball 19 is rollably stored between the cam grooves 17 and 18.

In such a cam mechanism 7, the two cam grooves 17, 18 have the deepest at the circumferential centers 17a0, 18a0, and the depth there is the radius of the ball 19 (D _B / 2:
D _B is set to the ball diameter) smaller dimensions.

In the embodiment, as will be described later in detail, the depth of the cam grooves 17 and 18 at the shallowest position is set to a dimension that prevents the ball 19 from coming off.

In the cam mechanism 7 of this embodiment, the cam grooves 17 and 18 are located at the deepest positions with the relative rotation of the flange 8 and the cam plate 4 with the rotation of the first rotary shaft 2. The ball 19 is located at the center 17a0, 18a0 in the circumferential direction.
Is positioned so that the cam plate 4 is close to the flange 8 side, and the ball 19 is positioned at the shallowest position between the two cam grooves 17 and 18 so that the cam plate 4 is most separated from the flange 8 side. State.

The operation of the clutch device A will be described with reference to FIGS. 1 to 3 and FIGS. 4 (a) and 4 (b).

In the illustrated state, the cam plate 4 is urged in the other axial direction by the disc spring 5, and the tapered surface 4a is pressed against the tapered surface 1a of the clutch housing 1. The rotation of the second rotating shaft 3 is locked and is in a non-rotating state. In this state, as shown in FIG. 4A, the ball 19 is located between the axially deepest circumferential centers 17a0, 18a0 of the cam grooves 17, 18, so that the first rotary shaft 2 and the cam plate 4 Is the shortest distance S2.

In this state, when the first rotary shaft 2 is driven to rotate by a power source such as a motor (not shown) (moved in one circumferential direction in FIG. 4), both opposing surfaces of the flange 8 and the cam plate 4 are provided. Mortar-shaped slopes 1 of cam grooves 17 and 18 between the opposite directions
The ball 19 rolls in the circumferential direction between 7a2 and 18a2 as shown in FIGS. 4 (a) to 4 (b). In the mortar-shaped slopes 17a2 and 18a2, as shown in FIGS. 4A and 4B, one mortar-shaped slope 17a2 faces the other in the circumferential direction, and the other mortar-shaped slope 18a2 faces one in the circumferential direction. Since the depth is small, the cam plate 4 is displaced (the maximum displacement amount is S1) from the flange 8 toward one side in the axial direction against the disc spring 5, whereby the cam plate 4 is displaced. The tapered surface 4a is separated from the tapered surface 1a of the inner peripheral surface of the clutch housing 1.

Then, the ball 19 is sandwiched in the axial direction between both sides of the mortar-shaped slopes 17a2, 18a2 as shown in FIG. 4 (b). At this time, the maximum axial separation distance between the first rotating shaft 2 and the cam plate 4 is S1 + S2.

As described above, the ball 19 is mortar-shaped slope 17
When the cam plate 4 is sandwiched in the axial direction between the two sides of the first rotation shaft a2 and the first rotation shaft 18a2, the cam plate 4 is rotated in the same direction by the rotation power T of the first rotation shaft 2 in one circumferential direction, and the second rotation is performed together therewith. The shaft 3 is also rotated in the same direction, and the rotation power T of the first rotation shaft 2 is transmitted.

When the first rotating shaft 2 is driven to rotate in the opposite direction to the above, the ball 19 is
a1 and 18a1, and the mortar-shaped slope 17a
1 and 18a1, the cam plate 4 is axially sandwiched between the two sides, and the cam plate 4 is rotated in the same direction by the other rotational power T in the circumferential direction of the first rotary shaft 2, and together with this, the second The rotation shaft 3 is also rotated in the same direction, and the rotation power T of the first rotation shaft 2 is transmitted.

Thus, the rotational power T is transmitted in any rotational direction.

The clutch device of the embodiment having the above-described structure can transmit the rotational power of the first rotating shaft 2 to the second rotating shaft 3 with high efficiency, while transmitting the rotating power from the first rotating shaft 2 to the second rotating shaft 3. Since the structure for transmitting the rotational power and separating the first rotary shaft 2 from the first rotary shaft 2 by making the second rotary shaft 3 non-rotating is simple, the cost of use and manufacture can be reduced.

Next, the cam mechanism 7 provided in the clutch device will be described with reference to FIGS. Note that FIG. 5 is a diagram showing FIG. 4 (a) and (b) together.
4A is shown by a solid line, and FIG. 4B is shown by a virtual line. Here, the symbols shown in these figures will be described.

The dimensional relationship for preventing the balls 19 from coming out of the cam grooves 17 and 18, that is, the depth of each of the cam grooves 17 and 18 at the deepest position of the ball 19 (the center 1 in the circumferential direction)
7a0, 18a0) are smaller than the radius of the ball 19, and when the ball 19 comes to the point a on the mortar-shaped slope, the step b of the cam groove for preventing the ball 19 from coming out is: The following expressions (1) to (3) are satisfied.

[0050] tanφ> (2 · T) / (Dp · Fs) and _{D B / 2> Ra ... (} 1) Dc> (S 1 / tanη) + D B · sinφ ... (2) S 2 <D B · cosφ -S ₁ ... (3) However, S _1: maximum axial displacement S ₂ of balls 19: axial separation shortest distance Dp between the first rotary shaft 2 and the cam plate 4: the pitch of the ball 19 circle diameter D _B: Diameter of ball 19 Dc: circumferential outer diameter of cam grooves 17, 18 θ: cam operating angle φ: cam stopper angle η: inclination angle of mortar-shaped slope [(π−θ) / 2] T: rotational power Fs: disc spring Here, the cam operating angle θ is the mortar-shaped slope 17a1, 17a2 adjacent to the cam groove 17 of the first rotary shaft 2 at the circumferential center 17a0, 18a0, that is, the deepest position.
And the opening angle of the mortar-shaped slopes 18a1 and 18a2 adjacent in the circumferential direction in the cam groove 18 of the cam plate 4.

The cam stopper angle φ is such that the ball 19 is sandwiched between the other circumferential side of the mortar-shaped slope 17a1 of the cam grooves 17 and 18 and one side in the circumferential direction of the mortar-shaped slope 18a1. , 18 mortar-shaped slopes 17a2
The angle between the contact point a of the ball 19 and the mortar-shaped slope and the axial line passing through the center of the ball 19 when the ball 19 is sandwiched between one circumferential side of the mortar-shaped slope 18a2 and the other side in the circumferential direction. .

Further, Ra is the ball 19 at the point b.
If the corner R between the plane in contact with the mortar and the mortar-shaped slope is larger than the radius of the ball 19, the ball 19 rides easily and is made smaller than the radius of the ball 19 to prevent it.

The meaning of each of the above formulas (1) to (3) will be described.

The left side of the equation (1) shows the relationship between the rotational power T and the cam stopper angle φ, and the right side shows the condition under which the ball 19 does not ride simply at the cam stopper angle φ.

Equation (2) shows the restriction on the circumferential outer diameter of the cam grooves 17 and 18.

Equation (3) shows the condition that the contact surface always exists on the ball 19 even when the depth of the cam stopper angle is φ.

In the relation of such an expression, the ball 19
In the embodiment, it is necessary that the depth of the reference position c of the cam angle Ra satisfies the expressions (1) to (3) in order to prevent the slipping out.

The operation of the cam mechanism 7 that satisfies the above equation will be described.

No rotational power is applied to the first rotating shaft 2 and, as shown by the solid line in FIG.
When the balls 7 and 18 face each other in the axial direction, the ball 19
Are circumferential centers 17a0, 18a of both cam grooves 17, 18
The cam plate 4 is axially opposed to the first rotating shaft 2 with a minimum separation distance S2 between 0. In this state, the cam plate 4 is urged in the other axial direction by the disc spring 5, and the tapered surface 4 a thereof is in pressure contact with the tapered surface 1 a of the clutch housing 1. Is locked in a non-rotating state.

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 19 moves the mortar-shaped slopes 17a2, 18a2 or 17a1, 18a1 of the cam grooves 17, 18 into one. Rolling, and FIG. 4 (b) or FIG.
As shown by the imaginary line, the mortar-shaped slope is sandwiched between both sides.

In this state, the separation distance between the first rotating shaft 2 and the cam plate 4 is S1 + S2, and the rotating power of the first rotating shaft 2 is transmitted to the second rotating shaft 3 as described above. .

At this stage, even if the first rotary shaft 2 is further rotating, the balls 19 are not provided with the cam grooves 17 and 18 because they have the above-mentioned relational expressions (1) to (4). 1
The mortar-shaped slopes 7 and 18 are prevented from slipping out.

The present invention is not limited to the first embodiment, and various applications can be modified.

(1) In the first embodiment, the outer peripheral surface of the clutch housing 1 and the inner peripheral surface of the cam plate 4 both have the tapered surfaces 1a, 4a. However, the present invention is not limited to this. Instead, the clutch housing 1 and the cam plate 4 are made to face each other in the axial direction, and the cam plate 4 is displaced in the axial direction.
May be pressed against or separated from the opposing surface of.

(2) In the above-described embodiment, the first rotating shaft 2 is prevented from shifting its relative position with the second rotating shaft 3 by the reaction force of the disc spring 5. The second rotary shaft 3 and the second rotary shaft 3 are integrally connected by a circlip, but this may be omitted, and instead, the first rotary shaft 2 is connected to the clutch housing as in the second embodiment of FIG. 1 may be rotatably supported via a rolling bearing 22.

(3) In the embodiment, the mortar-shaped slopes of the first rotating shaft 2 and the cam plate 4 are provided on both sides in the circumferential direction from the center in the circumferential direction. However, the present invention is not limited to this. One of the circumferential direction of the cam groove 17 and the other circumferential direction of the cam groove 18 in the opposite direction, or the other circumferential direction of the cam groove 18 and the circumferential direction of the cam groove 18 in the opposite direction. It may be simply formed.

(4) The clutch device of the embodiment can be applied to, for example, a continuously variable transmission, an electric power steering, and other mechanical devices.

[0068]

According to the first and second cam mechanisms of the present invention,
With a simple structure, it is possible to prevent the ball interposed between the cam grooves of the fixed cam plate and the movable cam plate from coming off.

According to the clutch device of the present invention, the rotational power of the first rotating body can be transmitted to the second rotating body with high efficiency by the movable friction member, the fixed friction member, and the cam mechanism. The manufacturing cost can be reduced. Further, in the case of the clutch device of the present invention, since the cam mechanism is incorporated, the ball interposed between the two cam grooves can be prevented from coming off, and the structure is excellent in reliability.

[Brief description of the drawings]

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

FIG. 3 is an exploded perspective view of the clutch device.

4A is an enlarged view of a main part of FIG. 1, and FIG. 4B is an enlarged view of a main part of FIG.

FIG. 5 shows a combination of FIGS. 4 (a) and 4 (b).

FIG. 6 is a side sectional view of the clutch device according to the second embodiment of the present invention corresponding to FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Clutch housing 2 1st rotating shaft 3 2nd rotating shaft 4 Cam plate 5 Disc spring 7 Cam mechanism 8 Flange (fixed cam plate) 17, 18 Cam groove

Claims (4)

[Claims] 1. A pair of fixed and movable cam plates, one of which is coaxially opposed to the other and is axially displaceable while the other is axially displaceable, and a pair of cam grooves are distributed on opposite surfaces. A ball rotatably housed between a pair of cam grooves of both cam plates; and a biasing member for resiliently biasing the movable cam plate toward the fixed cam plate side. A slope having a depth decreasing toward at least one circumferential direction, and a slope having a depth decreasing toward at least the other direction in the circumferential direction is provided in the other cam groove. The depth of the deepest position is set to a dimension smaller than the radius of the ball, and the depth of the shallowest position of each of the two cam grooves is set to a dimension to prevent the ball from coming out. With typical rotation The state is brought closer to the movable cam plate to the fixed cam plate side by the ball is positioned in the deepest position of both the cam groove, also,
A cam mechanism wherein the ball is located at the shallowest position between the two cam grooves so as to separate the movable cam plate from the fixed cam plate side. 2. A pair of fixed and movable cam plates, one of which is coaxially disposed so as to be axially displaceable and the other axially displaceable, and is provided with a pair of cam grooves distributed on opposing surfaces thereof. A ball rotatably accommodated between a pair of cam grooves of both cam plates; and a biasing member for resiliently biasing the movable cam plate toward the fixed cam plate side. , Is formed on a mortar-shaped slope having a depth decreasing from the circumferential center toward both sides in the circumferential direction, the depth of the deepest position of each of the two cam grooves is set to a dimension smaller than the radius of the ball, The depth of the shallowest position of each of the two cam grooves is set to a dimension that prevents the ball from coming out, and it is movable when the two cam grooves are aligned in the circumferential direction with the relative rotation of the two cam plates. Fix the cam plate State is closer to the cam plate side, also a state to separate the movable cam plate from the stationary cam plate side when both cam grooves are shifted in the circumferential direction, a cam mechanism, characterized in that. 3. The cam mechanism according to claim 2, wherein the dimensional relationship satisfies the following expressions (1) to (3).
A cam mechanism characterized in that: tanφ> (2 · T) / (Dp · Fs) and _{D B / 2> Ra ... (} 1) Dc> (S 1 / tanη) + D B · sinφ ... (2) S 2 <D B · cosφ-S 1 ... (3) where, S _1: axial ball direction maximum displacement amount S _2: axial shortest distance between the fixed cam plate and the movable cam plate Dp: the pitch of the ball circle diameter D _B: ball diameter Dc: cam groove : Outer diameter in the circumferential direction θ: Cam operating angle φ: Cam stopper angle η: Inclination angle of mortar-shaped slope [(π−θ) / 2] T: Rotating power (transmitted torque) Fs: Spring force of biasing member Ra: Corner R 4. A rotator is interposed between power transmissions of two rotators arranged coaxially and opposed to each other, and when the rotative power is input to the first rotator, the two rotators are coupled so as to be synchronously rotatable. On the other hand, a clutch device that separates the second rotating body from the first rotating body in a non-rotating state when rotational power is input to the second rotating body, and is disposed to face the first rotating body in the axial direction. A movable friction member which is rotatable synchronously with the second rotating body and is displaceable in the axial direction; and the movable friction member is 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 rotating body rotates, the movable friction member is separated from the fixed member when the first rotating body rotates, and the first rotating body, the movable friction member, and the second rotating body are integrated to synchronize the two rotating bodies. The second rotating body rotates while being rotatably connected And a cam mechanism for pressing the movable friction member against the fixed friction member to make the second rotating body, the movable friction member and the fixed friction member integral with each other to bring the second rotating body into a non-rotating state. 4. The cam mechanism according to claim 1, wherein the first rotating body is used as a fixed cam plate, and the movable friction member is used as a movable cam plate. A clutch device, wherein a member is displaced so as to be pressed against or separated from a fixed friction member.