JP2001140941A - Clutch device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a structure that performs such function that rotation of an input member 3a is transmitted to an output member 2a but rotation of the output member 2a is not transmitted to the input member 3a securely. SOLUTION: An input member 3a and an output member 2a are arranged on an inside diameter side of a fixed outer ring 1a. These input member 3a and output member 2a are combined in such a way that slight and free displacement in the circumferential direction becomes possible. Rolling elements 4, 4 are provided between a cam face 5a provided on an outer peripheral face of the output member 2a and a friction face 6a provided on an inner peripheral face of the outer ring 1a. When the input member 3a rotates, each of these rolling elements 4, 4 rolls, and when the output member 2a rotates, each of these rolling elements 4, 4 bites between the cam face 5a and the friction face 6a. Moreover, one side face in the axial direction of the input member 3a and one side face in the axial direction of the output member 2a which oppose mutually come into contact directly and freely only in the vicinity of the center of mutual rotation, and a friction torque acting on a contact part of both of these faces is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION A clutch device according to the present invention enables transmission of torque from a drive source to a driven body, but prevents transmission of torque from the driven body to the drive source. For example, it is used in a state of being incorporated in various driving devices such as a window regulator (including both an electric type and a manual type) for an automobile and an electric storage mirror.

[0002]

2. Description of the Related Art In the case of a window regulator for an automobile, for example, the rotation of an electric motor or a handle, which is a driving source, is transmitted to an elevating mechanism of a window glass. However, it is necessary to prevent the electric motor or the handle from rotating (for example, for security). As a clutch device having such a function, a clutch device described in JP-A-7-103260 has been conventionally known.

As shown in FIG. 15, the clutch device described in this publication has an outer ring 1, an output member 2, and an input member 3 as shown in FIG.
And a plurality of rolling elements 4 and 4 and a plurality of cam surfaces 5 and 5. Of these, the outer ring 1 has a cylindrical friction surface 6 on the inner peripheral surface, and does not rotate while being fixed to a window regulator frame or the like in use. The output member 2 is rotatably supported inside the outer ring 1 concentrically with the outer ring 1. The input member 3 has a plurality of arms 7. These arms 7, 7 are provided intermittently in the circumferential direction, and are inserted into an annular space 8 between the inner peripheral surface of the outer ring 1 and the outer peripheral surface of the output member 2. In addition, the plurality of rolling elements 4, 4
Is disposed between the arms 7 that are circumferentially adjacent to each other. Further, each of the cam surfaces 5, 5 is connected to the output member 2
Are formed at a plurality of locations on the outer peripheral surface of each of the rolling elements 4 and 4 opposite to each of the rolling elements 4 and 4. The center in the circumferential direction is located most inward in the diametric direction. It is inclined in the direction located.

[0004] In the clutch device as described above, the rotation of the input member 3 is independent of the rotation direction, and the arms 7, 7 are not rotated.
From the rolling elements 4 and 4. That is, when the input member 3 rotates, the inclined surfaces 9, 9 formed on the circumferential edges of the plurality of arms 7, 7 provided on the input member 3 cause the rolling elements 4, 4 to move to the respective rolling elements 4, 4. Press against each cam surface 5,5.
The rotation of the input member 3 is transmitted to the output member 2 by the engagement between the inclined surfaces 9 and 9 and the cam surfaces 5 and 5. On the other hand, when the output member 2 rotates, the cam surfaces 5 and 5 push the rolling elements 4 and 4 outward in the diameter direction of the output member 2, and the rolling elements 4 and 4 4 is pressed against a friction surface 6 provided on the inner peripheral surface of the outer ring 1. As a result, the rotation of the output member 2 is prevented by the frictional engagement between the rolling surfaces of the rolling elements 4 and the friction surface 6, and the rotation of the output member 2 is independent of the rotation direction. Transmission to the input member 3 is stopped.

[0005]

In the case of the conventional clutch device as described above, when the input member 3 rotates, all or some of the plurality of rolling elements 4, 4 are provided on the cam surface 5 provided on the output member 2 side. 5 and the friction surface 6 provided on the inner peripheral surface of the outer ring 1 may move to a position where they mesh with each other. For example, FIG.
Assuming that the up-down direction of the vehicle and the up-down direction in the actual installation state match, the lower rolling element 4 in FIG.
Actually, it does not exist at the position as shown in the figure, but is lowered to the position where it comes into contact with the friction surface 6 by gravity. When the arms 7 provided on the input member 3 rotate from this state, one of the arms 7 moves the lower rolling element 4 between the lower cam surface 5 and the friction surface 6. There is a possibility to move to the position where it meshes with. When the front and back directions in FIG. 15 coincide with the vertical direction, more rolling elements 4 and 4
It may be pushed to a position where the cam surfaces 5, 5 and the friction surface 6 are engaged with each other.

[0006] In this manner, with the rotation of the input member 3, all or a part of the rolling elements 4, 4 are brought into contact with the cam surfaces 5, 5 provided on the output member 2 side and the inner peripheral surface of the outer ring 1. Provided friction surface 6
The rotation of the input member 3 is not transmitted to the output member 2. The clutch device of the present invention has been invented in order to realize a structure capable of reliably transmitting the rotation of the input member to the output member without such a malfunction.

[0007]

A clutch device according to the present invention comprises an outer ring, an output member, an input member, a plurality of rolling elements, and a plurality of cam surfaces, similarly to the aforementioned conventional clutch device. Prepare. Of these, the outer ring has an inner peripheral surface as a cylindrical friction surface, and does not rotate in a fixed state in use. The output member is rotatably supported inside the outer ring concentrically with the outer ring. The input member has a plurality of arms. These arms are provided intermittently in the circumferential direction, and are inserted into an annular space between the friction surface provided on the inner peripheral surface of the outer race and the outer peripheral surface of the output member. Each rolling element is provided between arms adjacent in the circumferential direction in the annular space. Each of the cam surfaces is formed at a plurality of locations on the outer peripheral surface of the output member facing each of the rolling elements, and the center in the circumferential direction is located most inward in the diameter direction. Both ends in the circumferential direction are inclined in the direction located diametrically outward. The rotation of the input member is transmitted to the output member regardless of the rotation direction, but the rotation of the output member is not transmitted to the input member regardless of the rotation direction.

Particularly, in the clutch device of the present invention,
A contact portion is provided between the one axial side of the input member and the one axial side of the output member, which oppose each other, such that both sides directly contact each other only near the center of rotation of each other. In addition, at a portion of the output member and the input member that deviates from the contact portion, the two members are engaged with each other in a state where they are relatively displaced by a predetermined angle with respect to the rotation direction, and the rotation of the input member is controlled by the output member Is provided with an engaging portion that allows transmission. At the same time, an elastic member is provided between each circumferential side of each arm and each rolling element, and these rolling elements are elastically moved toward the center position of the arms adjacent in the circumferential direction. Pressing. When the input member rotates, the rotation of the input member is transmitted to the output member based on the engagement of the engagement portion, and the rolling elements are connected to the cam surfaces and the friction surfaces. It can roll freely between. On the other hand, when the output member tends to rotate with respect to the input member, the rolling elements move between the cam surfaces and the friction surfaces before the engagement portions are engaged. To prevent the output member from rotating with respect to the outer ring. In addition, as the contact portion, for example, a central portion of a convex surface directly formed near the rotation center of one side surface of one of the input member and the output member, and the input member and the output member It is possible to adopt a structure in which the center of a flat surface or a concave surface formed directly near the rotation center on one side of the other member is used.

[0009]

In the clutch device of the present invention having the above-described structure,
When the input member rotates, based on the engagement of the engagement portion,
The output member also rotates in the same direction. As the input member slightly rotates with respect to the output member until the engagement portion is engaged, each rolling element rotates the input member more than the center of the cam surface in the circumferential direction. Move a little forward in the direction. When the input member and the output member rotate in the same direction in this state, the rolling elements tend to be displaced toward the central portions of the cam surfaces. Therefore, these rolling elements do not mesh with each of the cam surfaces and the friction surface of the inner peripheral surface of the outer ring. As a result, the input member and the output member are rotatable inside the outer ring, and rotation can be transmitted from the input member to the output member. On the other hand, when the output member rotates with respect to the input member, before the engagement portion engages, that is, before the rotation of the output member is transmitted to the input member as it is, each of the rolling elements is rotated. It bites between each of the cam surfaces and the friction surface. As a result, the output member does not further rotate, and the rotation of the output member is not transmitted to the input member.

Further, in the case of the present invention, one side of the input member and one side of the output member are in contact only with contact portions provided near the center of rotation of each other. The other end of the output member is connected to a helical gear or a worm gear that constitutes a window glass elevating mechanism. When the input member and the output member are relatively rotated, these two members are connected to each other. The force in the pressing direction (axial direction) acts, but even in this case,
A large friction torque does not act on the contact portion between the one side surfaces of these two members. In other words, in the case of the present invention, the case where one side surface of these two members is in contact with the entire surface,
The friction torque acting on the contact portion between the one side surfaces of these two members (the distance from the contact portion to the center of rotation, Product with the acting frictional force) can be made sufficiently small. Therefore, it is possible to prevent the input member and the output member from rotating synchronously (or becoming unrotatable) due to the friction torque acting on the contact portion between the one side surfaces of the input member and the output member. As a result, when transmitting the rotation of the input member to the output member, the rolling elements bite between the respective cam surfaces and the friction surfaces, and the rotation of the input member cannot be transmitted to the output member, Alternatively, it is possible to effectively prevent the inconvenience that the biting state cannot be released. Note that these points will be described in detail in an embodiment of the present invention.

Here, in the case where one side surface of the input member and the one side surface of the output member are brought into contact only near the center of rotation of each other as in the present invention, the one side surfaces of these two members cover the entire surface. It is confirmed that the friction torque acting on the contact portion is smaller than in the case of contact. Now, let R be the radius of the contact portion between one side surface of the input member and one side surface of the output member, and let μ be the static friction coefficient of this contact portion. F is the axial force acting on the contact portion.

First, consider a case in which one side surface of the input member and one side surface of the output member are uniformly contacted over the entire surface. In this case, the surface pressure p ₁ acting on the contact portion between these one side surfaces
Is uniform over the entire surface of this contact,

(Equation 1) It is represented by Therefore, the friction torque T ₁ acting on the contact portion is:

(Equation 2) Becomes

On the other hand, a case where one side of the input member and the output member are brought into contact only near the center of rotation of each other as in the present invention will be considered. This case, the surface pressure p ₂ acting on the contact portion between the both side surfaces, (considered replaced) assumed to be represented by the distribution of the secondary curve becomes maximum at the rotation center,
Surface pressure p ₂ acting on the contact portion is a function of radius r centered at the rotation center. That is, if the proportional constant is k,

(Equation 3) It is represented by Here, from the force balance condition,

(Equation 4) Thus, the proportionality constant k is

(Equation 5) Becomes Therefore, the surface pressure p ₂ is

(Equation 6) It is expressed as Therefore, the friction torque T ₂ acting on the contact portion is

(Equation 7) Becomes

The friction torque T obtained as described above₁ And friction
Luc T_Two And T_Two <T ₁ Becomes That is, the book
As in the invention, one side of the input member and one side of the output member
Friction torque when contacting only near the rotation center of
T_Two Makes these sides contact each other over the entire surface
Friction torque T₁ You can see that it is smaller than
In the above comparative description, for the sake of convenience,
Also, the radius of the contact portion was the same (= R).
As in the embodiment described above, the radius of the contact portion is
Sufficiently smaller than the radius of the contact part when contacting over
To reduce the friction torque T_Two More (significantly)
Can be smaller.

In the case of the present invention, the vicinity of the center of rotation of one side of the input member and one side of the output member are brought into direct contact with each other. Can be formed directly on one side. Therefore, the contact portion can be formed integrally with the input member and the output member when the input member and the output member are processed or formed. For this reason, the contact portion can be provided at low cost.

[0016]

1 to 13 show a first embodiment of the present invention. Clutch device 10 of the present invention
Has an outer ring 1a, an output member 2a, an input member 3a, a plurality of rolling elements 4, 4, and a plurality of cam surfaces 5a, 5a.

The outer ring 1a is formed entirely of a hard metal plate such as carbonitrided steel in a cylindrical shape, and flanges 11a and 11b having inward flanges are provided at both ends in the axial direction to form the outer ring 1a. The output member 2a and the input member 3a are unitized so as not to come off from the inside, thereby facilitating the handling. A portion sandwiched between the flanges 11a and 11b on the inner peripheral surface of the outer ring 1a is a cylindrical friction surface 6a. The friction surface 6a has properties such as the outer raceway of a general cylindrical roller bearing, and has a smooth surface. When the clutch device 10 is in use, the outer ring 1a does not rotate while being fixed to a frame or the like of the window regulator.

In the illustrated example, both the flanges 11a, 1
1b, the width W of one (right side in FIG. 1) flange 11a.
_11a is larger than the width W _11b of the other flange 11b (W
_11a > W _11b ). It also has a large width _W11a ,
When the clutch device 10 is assembled, the thickness of the flange portion 11a, which is the bottom side (the side formed in advance before the assembly operation, the right side in FIG. 1) before the assembly operation, is set to the curl side ( It is larger than the thickness of the flange 11b (left side in FIG. 1). The reason for this configuration is that the bottom side flange 1
Whereas 1a it is easy to increase the width W _11a of, increasing the width W _11b of the curl side of the flange portion 11b,
This is because wrinkles are easily generated in the flange portion 11b. In other words, the width W of the flange 11b formed after the output member 2a and the input member 3a are inserted into the outer ring 1a.
This is because, when the size of the flange _11b is increased, the forming operation of the flange 11b becomes difficult in consideration of the quality of the flange 11b. Therefore, in the illustrated example, the curl-side flange portion 11b
And the outer diameter of the board portion 17 constituting the input member 3a is increased, so that the width W of the flange portion 11b is increased.
It is possible to make _11b smaller.

The output member 2a is, for example, an SMF4
As shown in FIG. 2, it is formed concentrically and integrally with the output shaft 12 by a hardened metal such as quenched and hardened metal such as 050 (JPMA 1) or a bearing steel. The outer ring 1a is supported concentrically and rotatably. The output shaft 12 is formed in a columnar shape, and when used, its distal end (the right end in FIGS. 1 and 2) is fitted and fixed in a circular hole provided on the driven member side by interference fitting. However, the connection between the output shaft 12 and the driven member is performed by spline engagement,
Other conventionally known engagement states such as key engagement may be adopted. On the other hand, the output member 2a is formed in an outward flange shape at one end (the left end in FIG. 2) of the output shaft 12.
On the outer peripheral surface of such an output member 2a, a plurality of (five in the example shown) cam surfaces 5a, 5a and engaging recesses 13, 13 are alternately provided at equal pitches in the circumferential direction. It is formed by. In addition, each of these engagement recesses 13 and 13
It is machined through to the end in the axial direction. As a result, the input member 3a is formed integrally with the input member 3a to be described later (in order to reduce the cost, the input member 3a is formed by injection molding of a synthetic resin.
The respective engaging projections 19, 19 (integrally formed with the above) are assembled to the respective engaging recesses 13, 13 from the axial direction, respectively.

Each of the cam surfaces 5a, 5a is located radially inward at the center in the circumferential direction, and is inclined in the direction toward the radially outer side toward both ends in the circumferential direction. In the case of the present example, such cam surfaces 5a, 5a have their circumferential ends curved in opposite directions to the rolling surfaces of the rolling elements 4, 4, respectively, as shown in detail in FIG. The two end convex curved surface portions 14 and 14 are provided, and the center in the circumferential direction is such that the edges of the pair of both end convex curved surface portions 14 and 14 are smoothly continuous.
A central concave curved surface portion 15 curved in the same direction as the rolling surfaces of the rolling elements 4 and 4 is provided. In the present invention, as will be described later, each of the both-end convex curved surface portions 14 and 14 serves as a cam surface for causing each of the rolling elements 4 and 4 to bite into the friction surface 6a of the outer ring 1a. In addition, two cam surfaces are provided for each rolling element 4.

The reason that the circumferential ends of the cam surfaces 5a, 5a are convex curved surfaces that are curved in the opposite direction to the rolling surfaces of the rolling elements 4, 4 is that each of the rolling elements 4, 5 has a convex curved surface. 4 is small (for example, 5 mm or less) even when the power is transmitted from the input member 3a to the output member 2a described below.
The rolling surfaces of the rolling elements 4 and the cam surfaces 5a, 5a
Alternatively, the radial gap between the friction surface 6a and the friction surface 6a is set to 0.
The rolling surface and the cam surface 5a, 5a or the friction surface 6a are prevented from rubbing each other so as to be able to secure about 1 to 0.2 mm, and the seizure resistance of both opposing surfaces is sufficiently ensured. That's why. At the same time, each rolling element 4,
The contact angle between each of the cam surfaces 5a, 5a and the rolling surface of each of the rolling elements 4, 4 (when the cam surface 4 bites) between the cam surfaces 5a, 5a and the friction surface 6a. In order to facilitate setting the angle between the normal line of the cam surface 5a at the contact point between the rolling surface 5a and the rolling surface and the load vector acting on this contact point) to an appropriate value of 4 to 5 degrees. It is. Conversely, if the circumferential ends of the cam surfaces 5a, 5a are not convex curved surfaces that are curved in the opposite direction to the rolling surfaces of the rolling elements 4, 4, the contact angle will be an appropriate value. It is difficult to make the angle 4 to 5 degrees (the contact angle easily exceeds 5 degrees).

The central concave curved surface portion 15 has a thickness of 0.5 to
It is formed on a partial cylindrical surface having a radius of curvature of about 1.0 mm to prevent a continuous portion between the ends of the convex curved portions 14 at both ends from becoming sharp. The reason for this is that, when the portion corresponding to the continuous portion has a sharp shape in the mold for sintering the output member 2a, the life of the sharp portion is shortened. In addition, it is for reducing the stress concentration in the continuous part at the time of torque load and preventing the output member 2a from being damaged.

The input member 3a is made of polyacetal.
Glass fiber mixed with polyamide 66
Sufficient hardness, rigidity, strength and dimensions of synthetic resin etc.
Injection molding of stable synthetic resin allows input
It is formed integrally with the shaft 16. The input member 3a is
Formed at one end of the input shaft 16 (the right end in FIGS. 1 and 5).
One side of the outwardly flanged substrate portion 17 (right side in FIGS. 1 and 5)
Surface) A plurality of (five in the example shown) arm parts on the outer diameter side
18, 18 are formed by joining the base ends. Each of these arms 1
As can be seen from FIG.
Arc-shaped, with the center axis of the input shaft 16 as its center
It is provided on the circle intermittently in the circumferential direction. Soshi
Between the arms 18 adjacent in the circumferential direction.
Pockets 20, 20 for holding the rolling elements 4, 4;
are doing. The width W of these pockets 20, 20₂₀Is the above
Outer diameter D of rolling elements 4, 4_Four Large enough than (Fig. 12)
(W ₂₀≫D_Four ). The center of the input shaft 16 is disconnected.
An engagement hole 24 having a non-circular surface shape is provided. When using
A drive (not shown) capable of changing the rotation direction is inserted into the engagement hole 24.
Inserting the tip of the output shaft of the dynamic motor,
a can be freely rotated in any direction. Input member 3
a shows the injection molding of the synthetic resin including the engagement hole 24 as described above.
It can be made by shape. Therefore, the above input with complex shape
The manufacturing cost of the member 3a does not increase.

The width of each of the arms 18 in the circumferential direction is large on the outside diameter side and small on the inside diameter side.
The reason for this is that the width W20 of each of the pockets 20, ₂₀ is made equal from the inner diameter side to the outer diameter side, and the respective arms 1
8 and 18, which will be described later, springs 21 and 21 (FIGS. 9 to
13) is to effectively prevent outward displacement due to centrifugal force. In addition, locking projections 22, 22 are respectively provided at the center in the circumferential direction of the outer peripheral surface of the distal end portion of each of the arms 18, 18.
Is formed. The locking projections 22 engage with the edges of the base 23 of the springs 21 to prevent the springs 21 from coming out of the arms 18. Things. Such locking projections may be provided not on the outer peripheral surface of each of the arms 18, but on the circumferential side surface.

Further, engaging projections 19, 19 are formed at the circumferentially intermediate portions of the inner peripheral surfaces of the arms 18, 18, respectively. As shown in FIGS.
In the assembled state, each of the engagement projections 19, 19 is provided with the engagement recess 13, which is formed on the outer peripheral surface of the output member 2a.
13 is engaged. The width W of each of the engaging projections 19, 19
₁₉ is sufficiently smaller than the width W ₁₃ of each of the engagement recesses 13, ₁₃ (W ₁₉ ≪W ₁₃ ). Therefore, the clutch device 1
In a state where the assembly 0 is assembled, the engaging projections 19, 19 and the engaging recesses 13, 13 are engaged with each other so as to be relatively displaceable in the circumferential direction. Then, the input member 3a and the output member 2a
Are combined so that they can be slightly displaced relative to each other in the rotation direction.

In practicing the present invention, the engaging portions that engage with each other in a state where the input member 3a and the output member 2a are relatively displaced by a predetermined angle are the engaging recesses 13 and 1 as described above.
3 and not only by the engagement of the engagement projections 19, 19,
Other structures may be employed. For example, the input member 3a
Of the opposing portions of one side surface (the right side surface in FIGS. 1 and 5) of the substrate portion 17 and the one side surface (the left side surface in FIGS. 1 and 2) of the output member 2a, it comes off from the convex portion 29 described below. Part
Concavo-convex engagement portions that engage with each other can also be provided. In the case of such a configuration, a space for the engagement recesses 13 formed on the outer peripheral surface of the output member 2a in the illustrated example is unnecessary, so that more cam surfaces are required. As a result, more rolling elements can be incorporated, and the torque capacity of the clutch device can be increased.

The central portion (rotation center portion) of one side surface of the substrate portion 17 is provided with a convex portion 29 projecting from the one side surface. In the case of this example, the surface of the convex portion 29 is a spherical convex surface. The central portion of the tip of the convex portion 29 is in contact with or close to the central portion (rotation center portion) on one side of the output member 2a. When one side surface of the substrate portion 17 and one side surface of the output member 2a are displaced in a direction approaching each other, these two side surfaces are connected to the protrusion 29.
Contact only at the contact portion between the central portion of the front end and the central portion on one side of the output member 2a. When the output member 2a is made of a metal and the input member 3a is made of a synthetic resin as in this example, the friction coefficient at the contact portion is reduced. The friction torque acting on the contact portion between the one side surfaces of these two members 2a, 3a is smaller than that in the case described above. In the case of this example, as described above, one side surface of both members 2a, 3a is brought into contact only at the center of rotation of each other, so that these two members 2a, 3a
The friction torque (the product of the distance from the center of rotation to the contact portion and the frictional force acting on the contact portion) acting on the contact portion between the one side surfaces is further reduced. In particular, in the case of the present example, the contact portion and the rotation centers of the two members 2a, 3a are made to coincide with each other, so that the friction torque acting on this contact portion can be extremely reduced. In the case of this example, in order to suppress the stress at the contact portion to be equal to or less than the allowable stress of the synthetic resin constituting the input member 2a, the radius of curvature of the outer surface of the convex portion 29 is set to:
A large value of about 10 to 20 mm is set to increase the contact area. In addition, since the convex portion 29 can be integrally injection-molded simultaneously with other portions constituting the input member 2a, it can be provided at a low cost.

A spring 21 as shown in FIGS. 9 to 11, which is an elastic material described in claim 2, is attached to each of the arms 18 constituting the input member 3a as described above. I have.
This spring 21, which is formed by bending an elastic metal plate such as stainless spring steel, includes one base portion 23 and a plurality (four in the illustrated example) of elastic pressing pieces 25, 25. The base portion 23 has an arc-shaped substrate portion 26 having a shape matching the outer peripheral surface of each of the arms 18, 18 so that the arms can be fitted to the arms 18 without looseness. The base 26 includes a pair of bent plates 27, 27 that are bent inward in the diametric direction from the center of both circumferential edges of the base end 26. In addition, locking portions 28, 28 bent in directions approaching each other are provided at the distal ends of the bent plates 27, 27, respectively.
And each of the locking portions 28, 28 and each of the arm portions 1
The inner peripheral surface of each of the inner peripheral surfaces 8 and 18 is freely engageable with the both ends in the circumferential direction. Each of the elastic pressing pieces 25, 25 has its base end connected to both side edges of each of the bent plate portions 27, 27.
3 has a resilience in a direction of being displaced away from.

The spring 21 as described above is mounted on each of the arms 18, 18 as shown in FIGS. In this mounting operation, the arms 18 are inserted into the base 23 from the front end side in the axial direction of the input shaft 16 (the left-right direction in FIG. 5 and the front and back directions in FIGS. 12 and 13). Perform in. As a result of this mounting operation, each of the arms 18, 18 is elastically displaced toward the outer diameter side in the circumferential direction of the substrate portion 26.
Pass through the locking projections 22 formed on the outer peripheral surface of the front end portion. After the passage, the engagement between the locking projection 22 and the edge of the substrate portion 26 causes the base portion 23 to move the arm portions 18,
18 is prevented from coming off in the axial direction. In addition, the respective bent plate portions 27, 27 and the respective locking portions 28, 2
8 engages with the circumferential side surfaces and the inner peripheral edge of each of the arms 18, 18, and allows the base 23 to engage with each of the arms 18, 1.
8 from being displaced toward the outer diameter side.

In the case where the engagement portion between the input member 3a and the output member 2a is provided on a portion of the input member 3a opposite to one side of the substrate portion 17 and one side of the output member 2a, Engagement projections 19,
19 can be omitted. In this case, the structure of the spring is reversed inside and outside in the diametric direction (the substrate portion is provided on the inner diameter side), and the spring is held in the arm portion 18 from the inner diameter side of the arm portion 18. It can also be attached to

The rolling elements 4 are mounted between the elastic pressing pieces 25 of the springs 21 attached to the arms 18 as described above, respectively. , 25 are held while being elastically displaced. Each of these rolling elements 4, 4 is like a cylindrical roller constituting a general cylindrical roller bearing, and is made of a hard metal such as high carbon chromium bearing steel. Each such rolling element 4,
4 is elastically pressed with the same force at the opposite ends in the circumferential direction at both axial ends by the elastic pressing pieces 25, 25 of the springs 21, 21, respectively. Therefore, each of the rolling elements 4, 4, when no external force is applied thereto, has the arm portions 18,
It is located in the central part between 18. The elastic pressing pieces 25, 25 press the rolling elements 4, 4 substantially straight in the circumferential direction. That is, the circumferential side surfaces of the arms 18 are parallel to each other for each side surface of the pockets 20, and the elastic pressing pieces 25 are parallel to the side surfaces. Provided. Therefore, each of these elastic pressing pieces 25, 25
Exists among the forces applied to the rolling elements 4, 4 from
The component force in the diameter direction of the input member 3a is extremely small.
The spring 21 configured as described above is provided with two sets of elastic pressing pieces 25, 25, one pair at each end in the circumferential direction, so that a separate spring structure is used for each elastic pressing piece. In addition to reducing the processing cost of the spring 21 itself,
By facilitating the mounting operation of the spring 21, the overall cost of the clutch device 10 can be significantly reduced.

The input member 3 combined as described above
a, the rolling elements 4, 4 and the springs 21, 21 are assembled into the outer ring 1a as shown in FIG.
The input member 3a and the output member 2a are arranged concentrically with each other, and loosely engage the engagement protrusions 19, 19 provided on the input member 3a side with the engagement recesses 13, 13 provided on the output member 2a side. Combine them together.

The input member 3a and the output member 2a thus combined are inserted into the outer ring 1a from the side where the thin flange 11b is to be formed. Then, the output shaft 12 is inserted inside the wide flange 11a, and the input member 3a and the output member 2a are connected to the outer race 1
a is located on the inner diameter side of the friction surface 6a. Then, the thin flange portion 11b is formed, and the clutch device 10 is completed.

The clutch device 10 is constructed as described above,
Further, when incorporated in a window regulator or the like, the input member 3a and the output member 2a are relatively displaced in a direction approaching each other, but limit the relative displacement in a direction away from each other. More specifically, the distance D ₀ of the opposite side surfaces of the output member 2a and the input member 3a in combination with one another, always the pair collar portion 11
a, smaller than the interval D ₁ of the inner surfaces of the 11b (D ₀
<D ₁ ). This is because the outer surface of the input member 3a is prevented from rubbing against the inner surface of the flange 11b, or the outer surface of the output member 2a is prevented from rubbing against the inner surface of the flange 11a. That's why.

For this purpose, for example, the engagement between the input shaft 16 integral with the input member 3a and the drive shaft (not shown) is devised (for example, the front end face of this drive shaft is attached to the back end face of the engagement hole 24). 1) to prevent the input member 3a from being displaced leftward from the state shown in FIG. 1, and to engage the output shaft 12 integrated with the output member 2a with a driven member (not shown). To prevent the output shaft 2a from being displaced rightward from the state shown in FIG. Therefore, when the input member 3a and the output member 2a rotate, these two members 3
a, 2a and the flanges 11a, 11b do not rub against each other, thereby preventing power loss and heat generation due to the rubbing. Further, since no load is applied to the flanges 11a and 11b, the thickness of the outer ring 1a can be reduced, and the entire clutch device 10 can be reduced in weight and size.

Further, the outer diameter of the substrate portion 17 constituting the input member 3a is made smaller than the inner diameter of the outer ring 1a (diameter of the friction surface 6a), and, of course, the arm portions 18, 18 are formed.
The diameter of the circumscribed circle of each of the springs 21 mounted on the outer ring 1a is also smaller than the inner diameter of the outer ring 1a. Therefore, even when the input member 3a rotates, the outer peripheral surfaces of the substrate portion 17 and the springs 21 and 21 do not rub against the friction surface 6a. For this reason, it is possible to prevent power loss and heat generation due to friction. The diameter of the circumscribed circle of each of the springs 21 is the same as that of the outer ring even when the displacement of each of the arms 18, 18 and each of the springs 21, 21 based on the centrifugal force caused by the rotation of the input member 3a is taken into account. It is made smaller than the inner diameter of 1a. Each of the arms 18, 18 based on the centrifugal force
For example, in the case of the clutch device 10 used for a window regulator, the displacement between the springs 21 and 21 and the friction surface 6a between the outer peripheral surfaces of the springs 21 and the friction surface 6a is small. If a gap of about 3 to 0.5 mm is interposed, the friction between the springs 21 and the friction surface 6a can be sufficiently prevented.

The axial movement of each of the rolling elements 4, 4 is prevented on the inner surface of the flange 11a formed on the outer ring 1a, thereby reducing the axial dimension (width) of the outer ring 1a. ing. That is, it is possible to provide a flange on the outer peripheral surface of the output shaft 12 and prevent the rolling elements 4 and 4 from moving rightward in FIG. 1 with this flange. The width of the outer ring 1a is increased by the thickness of the flange. An annular rim is provided over the entire circumference in a state where the tips of the arms 18 are connected to each other.
Can be prevented from moving to the right. In this case, the axial end surfaces of the rolling elements 4 and 4 do not rub against the inner surface of the collar portion 11a in a stationary state during use, and heat generation due to rubbing can be suppressed. However,
Also in this case, the outer ring 1a has a thickness corresponding to the thickness of the rim portion.
Becomes wider. In the illustrated example, the input member 3
The distal end surfaces of the arms 18 provided on the outer ring 1a rub against the inner surface of the flange 11a of the outer ring 1a. In order to prevent a large bending moment from being applied, the distal ends of the arms 18, 18 do not protrude from the end faces of the rollers 4, 4.

Next, the operation of the clutch device 10 of the present invention configured as described above will be described. First, a case where the rotation of the input member 3a is transmitted to the output member 2a, for example, when the window glass is moved up and down by an electric motor will be described with reference to FIG. In this case, the input member 3a rotates, for example, in the counterclockwise direction in FIG. 12, and the engaging protrusions 19 provided on the input member 3a side are provided on the output member 2a side. Each of the engagement recesses 13, 13
To the end in the circumferential direction. Then, the inner surface of each of the engaging recesses 13, 13 and the outer surface of each of the engaging protrusions 19, 19 abut (the engaging portions engage), and the input member 3 is engaged.
The rotation of a is transmitted to the output member 2a as it is, and the output member 2a rotates in the same direction and at the same speed as the input member 3a. The outer surfaces of the engaging projections 19, 19 and the inner surfaces of the engaging recesses 13, 13 correspond to the base ends of the engaging projections 19, 19 (the arms 18, 18). (The end near the inner peripheral surface). The reason for this is
When transmitting the rotational force from the input member 3a to the output member 2a, the bending moment applied to each of the engagement projections 19 is minimized to minimize the bending moment. This is to prevent the projections 19, 19 from being damaged.

As described above, the input member 3a is slightly moved relative to the output member 2a until the outer surfaces of the engaging projections 19, 19 and the inner surfaces of the engaging recesses 13, 13 abut. As it rotates, the rolling elements 4, 4
As shown in FIG. 2, the rotational direction of the input member 3a is slightly forward (leftward in FIG. 12) of the input member 3a relative to the circumferential center of the cam surfaces 5a and 5a provided on the outer peripheral surface of the output member 2a. Moving. As a result, each of the rolling elements 4, 4 is guided by the curved surfaces 14, 14 at both ends of each of the cam surfaces 5a, 5a, and is displaced radially outward of the output member 2a. Then, the rolling surfaces of the rolling elements 4 and 4 come into contact with the friction surface 6a of the outer race 1a.

As described above, when the input member 3a and the output member 2a rotate in the same direction with the rolling surfaces of the rolling elements 4 and 4 and the friction surface 6a of the outer ring 1a in contact with each other, Each rolling element 4, 4 tends to be displaced toward the central concave curved surface portion 15, 15 which is the central portion of each of the cam surfaces 5a, 5a. That is, when the input member 3a and the output member 2a rotate in the same direction in a state where the rolling surfaces of the rolling elements 4, 4 and the friction surface 6a of the outer race 1a are in contact with each other, the rolling elements 4, 4 No. 4 tries to stay at the same position based on the frictional engagement between the respective rolling surfaces and the friction surface 6a.
On the other hand, the output member 2a formed with the cam surfaces 5a, 5a rotates counterclockwise in FIG. 12, so that the rolling elements 4, 4 are formed on both side surfaces of the arms 18, 18, respectively. Of the elastic pressing pieces 25, 25 arranged on the front side, the elastic pressing pieces 25, 25 on the front side in the rotational direction are increased in the amount of compression and displaced rearward in the rotational direction with respect to the output member 2a. Therefore, each of the rolling elements 4, 4 is connected to each of the cam surfaces 5.
a, 5a and the friction surface 6a do not mesh with each other.
As a result, each of the rolling elements 4, 4
It moves to a portion where the distance between 5a and the friction surface 6a is large, and rolls at this portion. In this state, the outer ring 1a
The input member 3a and the output member 2a are in a rotatable state inside, and rotation can be transmitted from the input member 3a to the output member 2a.

When the frictional force acting on the contact portion between the rolling surfaces of the rolling elements 4 and 4 and the friction surface 6a is large, the rolling elements 4 and 4 are shown by chain lines in FIG. As described above, each elastic pressing piece 2 on the front side in the rotation direction of each of the arms 18, 18.
5, 25 may be completely crushed. When implementing the clutch device 10 of the present invention, even in such a state,
The engaging projections 1 are arranged so that the rolling elements 4 and 4 do not bite between the cam surfaces 5a and 5a and the friction surface 6a.
9 and ₁₉ and the width W _{13 of} each of the engagement recesses 13 and _13.
These engagement recesses 1 correspond to the difference (W ₁₃ −W ₁₉ )
The size δ of the displaceable gap of each of the engaging projections 19 within the third and third portions 13 is regulated. That is, the elastic pressing pieces 25 on the front side in the rotation direction of the arms 18 are moved by the rolling elements 4 and 4 into the arms 18.
Even if it is assumed that the rolling elements have been elastically deformed until they come into contact with the rolling elements, the rolling surfaces of the rolling elements 4 and 4 and the rear in the rotational direction (FIG. 1)
2) (the right side of FIG. 2) or the friction surface 6
The dimension relationship is such that a gap can be ensured with respect to a. In other words, each of the rolling elements 4, 4 is connected to each of the cam surfaces 5a, 5
a and the friction surface 6a, the dimensional relationship is such that rotation transmission from the input member to the output member is not disabled. In the above description, the case where the input member 3a rotates in the counterclockwise direction is described. However, when the input member 3a rotates in the clockwise direction, the same operation is performed except that the rotation direction is reversed.

The input member 3a and the output member 2a
Centering in the radial direction with respect to the diameter of the inscribed circle of each of the engagement projections 19, 19 and the engagement recesses 13, 1
The diameter of a circle connecting the bottoms of the engagement protrusions 3 is regulated, and the inner peripheral side surfaces of the engagement protrusions 19 are brought close to the bottoms of the engagement recesses 13. The input member 3a
When the engagement portion between the output member 2a and the engagement portion between the one side of the substrate portion 17 and the one side of the output member 2a on the input member 3a side is provided, By regulating the gap in the radial direction of the joint portion, it is possible to align the input member 3a and the output member 2a in the radial direction.

Next, although the electric motor is stationary and the input member 3a is stationary, a force in the direction of raising and lowering the window glass is applied, and a force in the rotational direction is applied to the output member 2a. FIG. 13 will be used to explain this case. In this case, as the output member 2a rotates counterclockwise in FIG.
Before the inner surface of the rolling element 3 comes into contact with the outer surface of each of the engaging projections 19, that is, before the rotation of the output member 2a is transmitted to the input member 3a as it is, each of the rolling elements 4, 4 are the cam surfaces 5a, 5a and the friction surface 6
bite between a. Moreover, in this case, the cam surfaces 5a, 5a are connected to the rolling elements 4, 4, respectively, and the rolling elements 4, 4 are connected to the cam surfaces 5a, 5a and the friction surface 6, respectively.
Only a force in the direction of digging is applied between them.
In other words, each rolling element 4, 4 is connected to each cam surface 5.
No force acts in the direction of displacement at the center in the circumferential direction of a and 5a. The force of the spring 21 is extremely small compared to the force required to rotate the input member 3a, and can be ignored in this case. Therefore, each of the rolling elements 4, 4
It bites between each of the cam surfaces 5a, 5a and the friction surface 6a to prevent the rotation of the output member 2a. As a result, the output member 2a does not rotate any more, and the rotation of the output member 2a does not transmit to the input member 3a. In the above description, the case where the output member 2a rotates in the counterclockwise direction has been described. However, when the output member 2a rotates in the clockwise direction, the same operation is performed except that the rotation direction is reversed.

In the case of the clutch device 10 of the present embodiment, the rolling elements 4, 4 are connected to the cam surfaces 5a, 5a and the friction surfaces 6 regardless of the direction in which the output member 2a rotates.
The reason why the spring 21 presses each of the rolling elements 4 and 4 from both sides in the circumferential direction to restrict the position of each of the rolling elements 4 and 4 in the circumferential direction is that the spring 21 presses the rolling elements 4 and 4 reliably. That's why. On the other hand, in the case of a structure in which the spring presses the rolling element in only one direction, the rolling element can be reliably engaged only when the output member rotates in a direction opposite to the pressing direction of the spring. Can not. In other words, the present invention presses the rolling elements 4 and 4 from both sides in the circumferential direction. Therefore, even when the output member 2a rotates in any direction, all the rolling elements 4 and 4 Engagement can be reliably performed between each of the cam surfaces 5a, 5a and the friction surface 6a.

The rolling elements 4 and 4 have the same size, and the cam surfaces 5a and 5a have the same shape and size. Therefore, when the output member 2a tends to rotate, the rolling elements 4, 4 all bite between the cam surfaces 5a, 5a and the friction surface 6a at the same time. Therefore, the torque applied to the output member 2a can be supported by all the rolling elements 4 and 4, and damage due to an excessive load applied to some of the rolling elements can be prevented. With respect to such a structure of this example, the same function can be exerted even if a plurality of sets (for example, three sets) of one-way clutch mechanisms having different rotation allowable directions are provided between the outer ring and the output member. . However, in this case, when the output shaft tends to rotate, only a part of the rolling elements will support the torque. As a result, the load applied to the motor increases and the torque capacity decreases, which causes a problem in securing durability.

As described above, the input member 3a and the output member 2
When power is transmitted between the two members 2a and 3a, the output member 2a receives an axial component force F from a helical gear fixed to the output shaft 12 or the like. May be pressed. At this time, if the friction torque acting on the contact portion between the one side surfaces of the two members 2a, 3a is large, the clutch device may malfunction. That is, if the friction torque acting on the contact portion is large, as described above, the input member 3a is transmitted to the output member 2a in order to transmit the rotation of the input member 3a (for example, FIGS. 12 to 13).
When rotated in the counterclockwise direction), each of the engagement recesses 13,
13, the output member 2a is connected to the input member 2a before the inner surface of the input member 13 contacts the outer surface of each of the engagement projections 19, 19.
(In the counterclockwise direction in FIGS. 12 and 13).
As a result, as shown in FIG.
Bites between the cam surfaces 5a, 5a and the friction surface 6a to rotate the input member 3a to the output member 2a.
(The same applies to the case where the input member 3a is rotated clockwise in FIGS. 12 and 13 except that the rotation direction is reversed).

On the other hand, as shown in FIG. 13, the input member 3a is moved from the state where the rolling elements 4, 4 bite between the cam surfaces 5a, 5a and the friction surface 6a (see FIG. 13). 1
3), and the rotation of the input member 3a is transmitted to the output member 2a, the friction torque acting on the contact portion between the one side surfaces of the two members 2a and 3a is considered. Is large, the output member 2a tends to rotate (counterclockwise in FIG. 13) in synchronization with the input member 3a. As a result, the state in which the rolling elements 4, 4 bite between the cam surfaces 5a, 5a and the friction surface 6a is maintained, and the rotation of the input member 3a cannot be transmitted to the output member 2a ( The same applies to the case where the input member 3a is rotated clockwise when the biting positions of the rolling elements 4 and 4 are opposite to the circumferential direction with respect to the state of FIG. 13).

In each case described above, each of the rolling elements 4,
In order to release the state in which the friction member 4 has bitten between the cam surfaces 5a and 5a and the friction surface 6a and transmit the rotation of the input member 3a to the output member 2a, the input member 3a
In addition, it is necessary to apply a driving torque larger than a friction torque acting on the contact portion and a friction force acting on a biting portion of each of the rolling elements 4, 4. However, it is not preferable to use a drive motor capable of providing such a large drive torque because the cost increases.

Further, when the input member 3a is stationary and a force is applied to the output member 2a in the rotational direction (for example, counterclockwise in FIGS. 12 and 13), the friction torque acting on the contact portion is large. Then, the input member 3a rotates in synchronization with the output member 2a (counterclockwise in FIGS. 12 and 13), and the elastic pressing pieces 25, 25 on the front side surfaces in the rotation direction of the arms 18, 18, respectively. The rolling elements 4 are pushed forward in the rotation direction. For this reason, each of the rolling elements 4, 4 has a convex curved surface portion 14 at the rear end in the rotational direction (rightward in FIGS. 12 and 13).
14, the input member 2a may not be able to prevent the rotation of the input member 2a (when the output member 2a rotates clockwise in FIGS. The same is true except for the opposite).

On the other hand, in the case of the present invention, one side of the input member 3a and one side of the output member 2a
By bringing only the rotation center portions into contact with each other, the friction torque acting on the contact portion between the one side surfaces of these two members 2a, 3a is sufficiently reduced. Therefore, based on the friction torque acting on the contact portion, the two members 2a, 3a
a can be prevented from rotating synchronously (or become unrotatable), and the above-described malfunction can be prevented. As a result, in the case of the present invention, the rotation of the input member 3a can be transmitted to the output member 2a with a small input torque, and
It is possible to effectively prevent the rotation of the output member 2a from being transmitted to the input member 3a.

Next, FIG. 14 shows a second example of the embodiment of the present invention. In the case of the present example, a spherical concave portion 30 which is recessed from one side surface of the substrate portion 17 constituting the input member 3b and a central portion of one side surface of the output member 2b (center of rotation) ) Are formed with spherical convex portions 31 protruding from one side surface. The radius of curvature of the spherical concave portion 30 is slightly larger than the radius of curvature of the spherical convex portion 31, and the height dimension h of the spherical convex portion 31 is larger than the depth dimension d of the spherical concave portion 30. It is slightly larger (h> d). And the spherical concave portion 3
The center portion (rotation center portion) of the zero and the center portion (rotation center portion) of the spherical convex surface portion 31 are in contact with or close to each other. When one side surface of the substrate portion 17 and one side surface of the output member 2b are displaced in a direction approaching each other, the two side surfaces are connected to the center of the spherical concave portion 30 and the center of the spherical convex portion 31. Contact only at the point of contact with the part.

Also in the case of the present embodiment configured as described above, one side of the input member 3b and one side of the output member 2b are
Since only the rotation center portions of the members 2b and 3b are in contact with each other, the friction torque acting on the contact portion between the side surfaces of the two members 2b and 3b can be sufficiently reduced. Therefore, also in the case of the present example, it is possible to prevent the malfunction of the clutch device as described in the first example. In the case of the present example, the spherical concave surface portion 30 and the spherical convex surface portion 31 come into contact with each other, so that the centering of the input member 3a and the output member 2a in the radial direction is automatically performed. As in the first example described above, it is not necessary to bring the inner peripheral surfaces of the engagement projections 19 of the input member 3a close to the bottoms of the engagement recesses 13 of the output member 2a. Also in the case of this example, since the spherical concave portion 30 can be formed integrally with the other portions constituting the input member 3b by injection molding of a synthetic resin, it can be provided at low cost. When the output member 2b is formed by forging a metal material such as S50C or S55C, the spherical convex portion 31 is formed integrally with other portions using the forging die. And the output member 2b is
When sintering a material such as MF4050, the sintering mold can be used to integrally form other parts. For this reason, the spherical convex portion 31 can also be provided at a low cost.

[0053]

Since the clutch device of the present invention is constructed and operates as described above, it is possible to realize a structure capable of reliably transmitting the rotation of the input member to the output member without malfunction.
Therefore, it is possible to reduce malfunctions and failures of various mechanical devices including the clutch device such as a window regulator.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first example of an embodiment of the present invention in an assembled state.

FIG. 2 is a cross-sectional view showing the output member.

FIG. 3 is a view seen from the left side of FIG. 2;

FIG. 4 is an enlarged view of a portion A in FIG. 3;

FIG. 5 is a sectional view showing the input member taken out therefrom.

FIG. 6 is a view seen from the right side of FIG. 5;

FIG. 7 is an enlarged view of a portion B in FIG. 5;

FIG. 8 is a view seen from the left side of FIG. 5;

FIG. 9 is a perspective view of a spring for pressing a rolling element.

FIG. 10 is a view taken in the direction of the arrow C in FIG. 9;

FIG. 11 is a view as seen from the direction of arrow D in FIG.

FIG. 12 is an enlarged cross-sectional view taken along the line EE of FIG. 1, showing a state where power is transmitted from the input member to the output member.

FIG. 13 is a view similar to FIG. 12, showing a state in which the output member tends to rotate and is locked.

FIG. 14 is a view similar to FIG. 1, showing a second example of the embodiment of the present invention.

FIG. 15 is a sectional view showing an example of a conventional structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1a Outer ring 2, 2a, 2b Output member 3, 3a, 3b Input member 4 Rolling element 5, 5a Cam surface 6, 6a Friction surface 7 Arm portion 8 Annular space 9 Inclined surface 10 Clutch device 11a, 11b Flange portion 12 Output Shaft 13 Engagement concave part 14 Both end convex curved part 15 Center concave curved part 16 Input shaft 17 Substrate part 18 Arm part 19 Engagement convex part 20 Pocket 21 Spring 22 Engagement projection 23 Base part 24 Engagement hole 25 Elastic pressing piece 26 Substrate part 27 bent plate part 28 locking part 29 convex part 30 spherical concave part 31 spherical convex part

Claims (2)

[Claims] 1. A fixed outer ring having an inner peripheral surface having a cylindrical friction surface, an output member rotatably supported inside the outer ring and concentrically with the outer ring, intermittently in a circumferential direction. And an input member having a plurality of arms inserted into an annular space between the inner peripheral surface of the outer ring and the outer peripheral surface of the output member, and arms circumferentially adjacent to each other in the annular space. A plurality of rolling elements provided between the portions, and a plurality of cam surfaces formed at a plurality of locations facing the respective rolling elements on the outer peripheral surface of the output member, and the rotation of the input member is In the clutch device which transmits to the output member irrespective of the rotation direction, but does not transmit the rotation of the output member to the input member irrespective of the rotation direction, the clutch device and the axially opposed one side surface of the input member oppose each other. Between both sides of the output member in the axial direction, these two sides are A contact portion that directly contacts only near the center of rotation is provided, and the two members are displaced relative to each other by a predetermined angle with respect to the rotation direction at a portion deviating from the contact portion between the output member and the input member. And an engagement portion for transmitting the rotation of the input member to the output member is provided. When the input member is rotated, the input portion is engaged based on the engagement of the engagement portion. While the rotation of the member is transmitted to the output member, the rolling elements are allowed to roll freely between the cam surfaces and the friction surface, and the output member tends to rotate with respect to the input member. In this case, the rolling elements bite between the cam surfaces and the friction surfaces before the engagement portions are engaged, thereby preventing the output member from rotating with respect to the outer ring. A clutch device characterized by the above-mentioned. 2. Each of the cam surfaces has a shape in which the center portion in the circumferential direction is located most inward in the diametrical direction, and each of the cam surfaces is inclined in such a direction as to be located diametrically outward toward both ends in the circumferential direction. Elastic members are respectively provided between the circumferential side surfaces of each arm and each rolling element, and these rolling elements elastically move toward the central position between the arms adjacent in the circumferential direction. The clutch device according to claim 1, wherein the clutch device is pressed.