JP2001271854A - Roller clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a roller clutch which is manufactured inexpensively and positively realize a lock state, without reducing torque capacity. SOLUTION: An outer ring 15 is made of synthetic resin, and it is so regulated that a specified wedge angle α2 defined in the assumed state of each roller 3, being held between the outer peripheral surface of a shaft 16 and a part of one circumferential end side part of each recessed part 20 of a cam face 21 provided at the inner peripheral surface of the outer ring 15 is larger than a prescribed wedge angle α1 defined in the assumed state of each roller 3 which is held between the outer peripheral surface of the shaft 16 and a part of the circumferential center side part of each recessed part 20. Accordingly, even if the outer ring 15 and the shaft 16 tend to relatively rotate to be in a locked state, each roller 3 is prevented from being displaced into a state of abutting against a part of each of pillar parts 19, 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION A roller clutch according to the present invention comprises two members concentrically combined with each other.
When one member makes a bidirectional rotational movement, it is used when only one of the rotational movements is transmitted to the other member.

[0002]

2. Description of the Related Art A fully automatic washing machine, a copying machine, a facsimile, or an alternator which is a kind of engine auxiliary machine,
2. Description of the Related Art Roller clutches that transmit only a rotational motion in a specific direction are incorporated in rotation transmission units of various types of mechanical devices and used. 6 and 7 show an example of such a roller clutch.

The roller clutch 1 includes an outer ring 2, a plurality of rollers 3, 3, springs 4, 4, each of which is made of an elastic material, and the same number of springs 4, 4, a cage 5, And an inner ring 6 as a member. The outer race 2 is formed in a cylindrical shape from a steel plate. When used, the outer race 2 is internally fitted and fixed inside a holding member 13 having an inner peripheral surface as a cylindrical surface, such as a housing attached to a main body of a fully automatic washing machine. The inner peripheral surface of such an outer ring 2 is a cam surface 7 which is an uneven surface extending in the circumferential direction. That is, recesses 8, called ramps, are formed at a plurality of circumferential positions on the inner peripheral surface of the outer ring 2 at equal intervals along the axial direction of the outer ring 2. ing. A cylindrical gap 12 is formed between the outer peripheral surface of the inner ring 6 and the inner peripheral surface of the outer ring 2, and the size of the cylindrical gap 12 depends on the diameter of the outer ring 2 (up and down in FIGS. 6 and 7). The width dimension in the direction) is larger than the outer diameter of each of the rollers 3, 3 at the portion corresponding to the deepest portion of each of the concave portions 8, 8, and at the portion outside of each of the concave portions 8, 8, these rollers 3, 3 is smaller than the outside diameter. In addition, flanges 9a and 9b in the form of inward flanges are formed at both axial ends of the outer ring 2 by bending a metal plate constituting the outer ring 2 inward in the diameter direction.

On the other hand, the cage 5 constituting the roller clutch 1 is formed in a cage shape and a cylindrical shape by injection molding synthetic resin. Then, the retainer 5 is provided inside the outer ring 2, and the convex portion 1 formed on the outer peripheral surface of the retainer 5 is provided.
0, 10 are formed in concave portions 8, 8 formed in the inner peripheral surface of the outer ring 2.
, So that relative rotation with respect to the outer ring 2 is impossible. The plurality of rollers 3, 3 are held inside the pockets 11, 11 formed in such a retainer 5 so as to roll and slightly displace in the circumferential direction. Further, each of the springs 4 is provided with a retainer 5 as described above.
Are provided between the pillars 14 and 14 and the rollers 3 and 3, and these rollers 3 and 3 are elastically pressed in the same direction (left direction in FIG. 7) with respect to the circumferential direction. I have.

[0005] The roller clutch 1 constructed as described above is
A holding member 13 to which the outer ring 2 is fitted and fixed;
Only a rotational force in a predetermined direction is transmitted to a shaft (not shown) externally fitted and fixed. For example, assuming that the outer ring 2 is fixed and only the inner ring 6 rotates in FIG. 7, when the inner ring 6 rotates clockwise in FIG. Based on the force received, each of the above springs 4,
4 tends to be displaced toward the side where the concave portions 8 become deeper. Then, each of the rollers 3, 3 is
Rolling is possible in the cylindrical gap 12, and a so-called overrun state occurs in which transmission of rotational force between the outer ring 2 and the inner ring 6 is not performed. On the other hand, when the inner ring 6 rotates in the counterclockwise direction in FIG. 7, the rollers 3, 3 receive the force from the outer peripheral surface of the inner ring 6 and the elasticity of the springs 4, The recesses 8, 8 bite into the shallow side in a wedge shape, and the outer ring 2 and the inner ring 6 are integrally connected to each other, so that the rotational force can be freely transmitted between the outer ring 2 and the inner ring 6. , A so-called locked state.

In the roller clutch 1 described above, the cam surface 7 is formed on the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the inner ring 6 is a cylindrical surface. However, the peripheral surface forming the cam surface may be reversed. . That is, in this case, a concave portion is formed in the outer peripheral surface of the inner ring, and the outer peripheral surface of the inner ring is used as a cam surface, and the inner peripheral surface of the outer ring is used as a simple cylindrical surface.

On the other hand, the outer ring 2, the inner ring 6, and the plurality of rollers 3, 3 may have dimensional errors that are unavoidable in terms of manufacturing diameter. In a state where such a dimensional error has occurred, the rollers 3, 3
When the recesses 8 tend to be displaced toward the shallower side, the position at which the rollers 3 are clamped between the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the inner ring 6 is determined. There is a possibility that each completed roller clutch 1 differs. For this reason, conventionally, the cross-sectional shape of each of the concave portions 8 has been described by a logarithmic spiral curve (lo).
By adopting a curve approximating a garithmic spiral curve, the locked state of the roller clutch 1 can be reliably realized even if the dimensional error occurs.

For example, as shown in FIG. 8, between the inner peripheral surface of the outer race 2 and the outer peripheral surface of the inner race 6, two rollers 3a, 3b having different outer diameters due to manufacturing errors are respectively held. Suppose that The cross-sectional shape of the concave portion 8 formed on the inner peripheral surface of the outer ring 2 is a logarithmic spiral curve. In this case, the predetermined wedge angles α _3a and α _3b established for each of the rollers 3a and 3b are equal to each other. Here, the wedge angles α _3a and α _3b are points at which the rolling surfaces of the rollers 3a and 3b are in contact with a part of the recess 8 when viewed in a cross section orthogonal to the axial direction of the rollers 3a and 3b. Tangents L _3a and L _3b at
The angle at which the tangents L _3a ′ and L _3b ′ at the points where the rolling surfaces of the rollers 3 a and 3 b come into contact with a part of the outer peripheral surface of the inner race 6. The wedge angles α _3a and α _3b are set to be smaller than twice the value of the friction angle. That is, a value twice as large as the friction angle tan ^-1 μ defined when the friction coefficient between the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the inner ring 6 and the rollers 3a and 3b is μ. The wedge angles α _3a and α _3b are smaller than the above (α _3a ,
α _3b <2 · tan ^-1 μ). Wedge angle α as described above
_{Since 3a} and α _3b are equal to each other, the above tangents L _3a ,
Acting in a direction perpendicular to L _3b , L _3a ′, and L _3b ′, the contact loads applied to the rollers 3a, 3b from the outer ring 2 and the inner ring 6 are equal to each other for the rollers 3a, 3b. Accordingly, when the cross-sectional shape of the concave portion 8 is as described above, regardless of the existence of the dimensional error, the contact load applied to the rollers 3 from the outer ring 2 and the inner ring 6 in the locked state. The load can be balanced, and the locked state can be reliably realized. If the cross-sectional shape is a shape approximating a logarithmic spiral curve, the wedge angle in the locked state changes when the dimensional error occurs, but the amount of the change is extremely small. Above, this change in wedge angle is negligible.

Further, in the conventional roller clutch 1, the plurality of rollers 3, 3 and the outer ring 2 and the inner ring 6 are all made of steel. Therefore, a relatively large torque is transmitted between the outer ring 2 and the inner ring 6, and each contact portion between the rolling surface of each of the rollers 3 and the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the inner ring 6. Even when a relatively high surface pressure acts on these members, these members 3, 2, 6 can be hardly deformed. Therefore, in the conventional structure, it is unlikely that the wedge angles change due to the deformation of the members 3, 2, and 6 during use.

[0010]

In recent years, it has been considered that one of the outer ring and the inner ring, which forms a cam surface on the peripheral surface thereof, is formed by injection molding synthetic resin.
According to this configuration, the cam surface provided on the one member can be formed at the same time as the injection molding of the synthetic resin, and a part serving as a retainer is provided on a part of the one member, Since the roller clutch can be formed integrally with the roller clutch, the roller clutch can be manufactured at low cost.

However, when the one member is made of a synthetic resin, the roller clutch may not function properly depending on the use of the roller clutch. That is, when such a roller clutch is used for an application in which a relatively large torque is transmitted between the outer ring and the inner ring, the one member made of synthetic resin acts at a contact portion with each roller. It may not be able to withstand the surface pressure that occurs and may be deformed early. In such a case, when the outer ring and the inner ring tend to rotate relative to each other in order to be in a locked state, each roller plastically deforms each recess formed on the peripheral surface of the one member, The rollers themselves are also elastically deformed, and the rollers are displaced at one circumferential end of the recesses to the side where the recesses become shallower. Thus, even when each roller is displaced, a contact load of a desired size can be applied from the outer ring and the inner ring to a certain position. However, in a state where each of the rollers is displaced until it abuts on a part of a pillar portion provided on a part of the one member and serving as a part of a retainer, a sufficiently large contact load is applied. No lock is applied and the locked state cannot be realized.

On the other hand, by reducing the number of the rollers and the columns, a sufficient length of the rollers until they come into contact with a part of the columns is secured, and the locked state is maintained. It is also conceivable to make sure it can be realized. However,
In such a case, the torque capacity of the roller clutch is reduced by an amount corresponding to the reduction in the number of rollers, so that it may not be adopted depending on the application. In view of such circumstances, the present invention realizes a roller clutch that can reliably realize a locked state without reducing the torque capacity even when the outer ring or the inner ring is made of synthetic resin in order to manufacture it at low cost. It was invented to do so.

[0013]

A roller clutch according to the present invention has an outer ring having a cylindrical inner peripheral surface and a concentric arrangement with the outer ring inside the outer ring, similarly to the above-mentioned conventional roller clutch. An inner member having a cylindrical outer peripheral surface,
On one of the inner peripheral surface of the outer ring and the outer peripheral surface of the inner member, the thickness in the circumferential direction of the gap between the inner peripheral surface of the outer ring and the outer peripheral surface of the inner member is defined in the circumferential direction. The cam surface formed by intermittently forming recesses that gradually change over a plurality of locations in the circumferential direction, and the recesses in a cylindrical gap between the outer peripheral surface of the inner member and the inner peripheral surface of the outer ring. A plurality of rollers inserted in a portion that matches with each other, provided between the member provided with the cam surface and each roller, and directing each roller in a direction in which each recess becomes shallow, and having the same circumference. And an elastic material for pressing in the direction.

In particular, in the roller clutch of the present invention, the member provided with the cam surface is made of synthetic resin. Then, each of the rollers is displaced at a circumferential end of each of the concave portions to a side where these concave portions become shallow, and a part of each of the concave portions and an inner peripheral surface of the outer ring and an outer peripheral surface of the inner member are displaced. In a state of being sandwiched between a part of the other peripheral surface,
Seen in a cross section orthogonal to the axial direction of each roller, a tangent line at a point where the rolling surface of each roller contacts a part of the other peripheral surface, the rolling surface of each roller, and each recess The angle at which a tangent at a point where a part of the tangent intersects is defined as a wedge angle.
In this case, each of the concave portions and the other peripheral surface are not deformed, and the outer diameter of each of the rollers is reduced. The wedge angle in a state assumed to be sandwiched between a part of the other peripheral surface, the concave portions and the other peripheral surface are not deformed, and the outer diameter of each roller does not decrease, Each of these rollers is larger than the wedge angle in a state where it is assumed that the rollers are sandwiched between a part of the concave portion of the concave portion near the center in the circumferential direction and a part of the other peripheral surface. The outer diameter of each of the rollers hardly actually expands and contracts regardless of the load applied during use. The description that the outer diameter of the roller becomes smaller as described above is a hypothesis for explaining the cross-sectional shape of the concave portion. This is the same throughout this specification.

[0015]

With the roller clutch of the present invention configured as described above, of the two members concentrically combined with each other,
When one member makes a bidirectional rotational movement, the action of transmitting only one of the rotational movements to the other member is:
It is the same as a conventional roller clutch. Particularly, in the case of the roller clutch of the present invention, since the member provided with the cam surface is made of synthetic resin, the roller clutch can be manufactured at low cost,
The weight of the roller clutch can be reduced. Further, according to the roller clutch of the present invention, when this roller clutch is used for an application in which a large torque is transmitted between the outer ring and the inner ring, each roller has a shallower concave portion so as to be locked. If the roller is to be displaced to one end in the circumferential direction, the predetermined wedge angle becomes large, and the contact load acting between each roller and the outer ring and the inner member decreases. Because of this,
The elastic deformation of each part is suppressed, and each roller does not displace until it hits a part of the pillar part, which functions as a part of the retainer. Therefore, according to the present invention, the locked state can be reliably realized. Moreover, in the case of the present invention, the number of the rollers does not have to be reduced in order to reliably realize the locked state, so that a sufficient torque capacity can be secured.

[0016]

1 to 3 show, as a first embodiment of the present invention, a drive (not shown) for a shaft 16 such as a copying machine, a facsimile paper feed roller or a paper discharge roller. A roller clutch 1a for transmitting only rotation in a predetermined direction by a gear is shown. This roller clutch 1a
Has an outer ring 15, an inner member, a shaft 16, and a plurality of rollers 3,3. The outer ring 15 is formed by injection-molding a synthetic resin such as polybutylene terephthalate resin (PBT) in which glass fiber is mixed in an amount of about 30%, and forms a spur gear 17 which is a driven gear on the outer peripheral surface. The inner peripheral surface is cylindrical. In addition, as the above-mentioned synthetic resin, in addition to the above-mentioned polybutylene terephthalate resin, a high-performance resin such as a polyacetal resin, a polyamide 66 resin mixed with glass fibers, or the like can also be used.

A pair of flanges 18 are formed at both ends in the axial direction of the inner peripheral surface of the outer ring 15 so as to protrude toward the inner diameter over the entire circumference. In addition, a plurality of pillar portions 19, 19 are provided at equal circumferential positions on a portion of the inner peripheral surface of the outer ring 15 located between the pair of flange portions 18, 18.
Are formed so as to protrude toward the inner diameter side, respectively. In the inner peripheral surface of the outer ring 15, a plurality of recesses 20, 20 which become shallower toward the one end side in the circumferential direction (the left side in FIG. 2) are provided in the portion between the column portions 19, 19.
The cam surface 21 is formed at an axially intermediate portion of the inner peripheral surface of the outer ring 15 by being formed at circumferentially equal intervals. In addition, both circumferential sides of each of the column portions 19 and 19 are connected to the outer ring 15.
Are inclined in the same circumferential direction as the diameter direction.

On the other hand, the shaft 16 is made of steel, and the outer peripheral surface of the intermediate portion has a simple cylindrical shape. The intermediate portion of the shaft 16 is arranged inside the outer ring 15. In this state, a cylindrical gap 12 is formed between the inner peripheral surface of the outer ring 15 and the outer peripheral surface of the shaft 16, and the size of the cylindrical gap 12 is the width of the outer ring 15 in the diameter direction. The dimensions are
In a portion corresponding to the deepest portion of each of the concave portions 20, 20, the outer diameter of each of the rollers 3 is larger than that of each of the rollers 3.
In the portion deviating from 20, the outer diameter of each of the rollers 3, 3 is smaller.

The rollers 3, 3 are rolled and rolled into a space surrounded by a portion of the inner peripheral surface of the outer ring 15 corresponding to the recesses 20, 20 and an outer peripheral surface of the shaft 16. It is held so as to be slightly displaceable in the circumferential direction. In addition, one side surface of each of the column portions 19, 19 in the circumferential direction (FIG. 2)
And a plurality of springs 22 each of which is an elastic material. Each of these springs 22 is a synthetic resin spring formed integrally with the outer ring 15 at the time of injection molding of the synthetic resin constituting the outer ring 15. Each of these springs 22 is formed in a substantially V-shape as a whole, and each of the intermediate portions is provided with the above-mentioned column portion 19, 1
9 on one side in the circumferential direction. Then, both ends of each of the springs 22 are elastically pressed against the rolling surfaces of the rollers 3, 3 so that the springs 22 cause the rollers 3, 3 to move in the same direction in the circumferential direction (FIG. 2). To the left). Also, each of these rollers 3,
3 is a pair of flanges 18 provided on the inner peripheral surface of the outer ring 15;
The axial displacement is regulated by 18. In this example, since each of the springs 22 each having a complicated shape as described above is provided integrally with the outer ring 15, these outer rings 1 are provided.
5 and the spring 22 are formed by injection molding of a synthetic resin using a radial draw mold. The basic structure and operation of the roller clutch 1a are substantially the same as those of the conventional structure shown in FIGS.

In particular, in the case of the roller clutch 1a of the present invention, the torque capacity can be reduced even when the roller clutch 1a is used for an application in which a large torque is transmitted between the outer ring 15 and the shaft 16. In order to reliably realize the locked state, the sectional shape of each of the recesses 20 is devised. In order to explain the cross-sectional shape of each of the concave portions 20, 20, the rollers 3, 3 are provided with the concave portions 20, 20, respectively.
At one end in the circumferential direction, the recesses 20 are displaced toward the shallower side, and are sandwiched between a part of the recesses 20 and a part of the outer peripheral surface of the shaft 16. , viewed in cross section perpendicular to the axial direction of the rollers 3, 3, a portion in contact with a point P of the rolling surface above the recesses 20, 20 of the rollers 3, 3, tangent L _P at P' , L _P ′ and a point N at which the rolling surface of each of the rollers 3, 3 contacts the outer peripheral surface of the shaft 16,
The angle at which the tangents L _N , L _N ′ at _N ′ intersect is the wedge angle α.
₁ and α ₂ . Note that these wedge angles α ₁ and α
₂ are straight lines PR and P'R passing through the points P and P 'and the centers S and S' of the roller 3, and straight lines SO and S'O passing through the centers S and S 'and the center O of the shaft 16. 2, the wedge angles α ₁ and α ₂ are shown as these angles (∠OSR, ＲOS′R) in FIG. And
In the present invention, the outer peripheral surfaces of the recesses 20, 20 and the shaft 16 are not deformed, and the outer diameters of the rollers 3, 3 are reduced. A state in which the roller 16 is assumed to be sandwiched between a part of a portion near one end in the circumferential direction and a part of the outer peripheral surface of the shaft 16 (see FIG.
Is indicated by a dashed line), and the wedge angle α ₂ is
The outer surfaces of the rollers 0, 20 and the shaft 16 are not deformed, and the outer diameter of each roller 3 is not reduced.
Is displaced to one end side in the circumferential direction of each of the recesses 20, 20,
In a state where it is assumed that the roller 3 is sandwiched between a part of the recess 20 near the center in the circumferential direction and a part of the outer peripheral surface of the shaft 16 (the roller 3 is shown by a solid line in FIG. 2). Is larger than the above wedge angle α ₁ (α ₂ > α ₁ ).

For this reason, in the case of the present embodiment,
The cross-sectional shape of 20 is regulated as follows. First, the outer peripheral surfaces of the recesses 20 and 20 and the shaft 16 are not deformed, and
Without the outer diameter of each roller 3 being reduced, each roller 3 is displaced to one end in the circumferential direction of each of the recesses 20, 20, and a part of each of the recesses 20, 20 near the center in the circumferential direction. And a part sandwiched between the shaft 16 and a part of the outer peripheral surface of the shaft 16. In this state, when viewed in a cross section orthogonal to the axial direction of each roller 3, the point P at which the rolling surface of each roller 3 contacts the inner peripheral surface of the outer ring 15 and the center O of the shaft 16.
And a straight line L orthogonal to the center O with respect to the straight line PO connecting
Define _A. Then, the straight line L _B passing through the center S of the point P and the roller 3, the intersection between the straight line L _A and Q.
Then, a point R is determined on the straight line PQ such that the length from the point P is 0.8 times the length of the straight line PQ,
An arc having the point R as its center and the length of the straight line PR as its radius is the cross-sectional shape of each of the recesses 20.

On the other hand, conventionally, each of the concave portions 20 is
By making the cross-sectional shape of 20 an arc (the arc shown by the broken line in FIG. 2) with the point Q as its center and the length of the straight line PQ as its radius, the cross-sectional shape approximates a logarithmic spiral curve. It was made to become a curved line. Therefore, in the case of this example, the curvature of the circular arc of the cross-sectional shape is larger than that of the conventional structure, and the wedge angle is such that each of the rollers 3 is directed toward one circumferential end of each of the concave portions 20, 20. It becomes larger as it is displaced. In particular, in the case of this example, the wedge angle α ₁ is 9 when the rollers 3 are assumed to be in contact at the point P.
And the outer diameter of each roller 3 becomes smaller,
Each of the rollers 3 is displaced to a position near one end in the circumferential direction of each of the concave portions 20, 20, and the wedge angle α _{2 is set} to 11 degrees under the assumption that the rollers 3 are in contact with a part of each of the column portions 19. .

When using the roller clutch of the present invention configured as described above, the spur gear 17 provided on the outer peripheral surface of the outer race 15 is used.
And a drive gear (not shown). When the outer ring 15 rotates in both directions via the driving gear, only the rotation of the outer ring 15 in one direction is applied to the shaft 16.
Can be transmitted to In particular, in the case of the roller clutch of the present invention, since the outer ring 15 is made of synthetic resin,
The process of forming the cam surface 21 on the inner peripheral surface of the outer ring 15
This can be performed simultaneously with the injection molding of the outer ring 15. Because of this,
There is no need to separately provide a processing step for the cam surface 21. Moreover, the pillars 19, 1 and 1 function as a part of the cage.
9 and the spring 22 can be provided integrally with the outer ring 15. As a result, the roller clutch 1a can be manufactured at low cost.
Further, by making the outer race 15 made of a synthetic resin, the weight of the roller clutch 1a can be reduced.

Further, according to the roller clutch 1a of the present invention, even if the roller clutch 1a is used for an application in which a large rotational torque is transmitted between the outer ring 15 and the shaft 16, the locked state can be ensured. realizable. The reason will be described below. First, as shown in FIG. 3, it is assumed that the roller 3 is sandwiched between a part of the concave portion 20 formed on the inner peripheral surface of the outer ring 15 and a part of the outer peripheral surface of the shaft 16. In this case, the roller 3 has a contact point P with the recess 20 and a contact point N with the outer peripheral surface of the shaft 16 from the outer ring 15 and the shaft 16 in the opposite directions (contact load).
F acts. On the other hand, viewed in cross section perpendicular to the axial direction of the roller 3, the tangent L _N rolling surface of the roller 3 at the N points in contact with the outer peripheral surface of the shaft 16, the rolling surface of the roller 3 above When the tangent L _P and intersects angle part in contact with a point P of the concave portion 20 and the wedge angle alpha _1, the direction of the tangent line L _N is a force of Fsin (α _1/2). Therefore, assuming that the radius of the shaft 16 is R and that z rollers 3 are arranged around the shaft 16, the outer ring 15 and the shaft 1
6 is equal to zR Fsin (α ₁
/ 2). Therefore, this torque T ｛= z · R
· Fsin with (α _1/2)} is constant, the z and R is also assumed to be constant, as the aforementioned wedge angle alpha ₁ is increased, the contact load F becomes smaller. Incidentally, a component force of this contact load _{F, Fcos (α 1/2} ) is a internal stress of the roller clutch 1a.

On the other hand, in the case of the present invention, as described above, the outer peripheral surfaces of the recesses 20 and 20 and the shaft 16 are not deformed, and the outer diameter of the rollers 3 is reduced. The wedge angle α ₂ under the condition that each roller 3 is sandwiched between a part of a portion of the concave portion 20 near the one end in the circumferential direction and a part of the outer peripheral surface of the shaft 16 is defined as The outer peripheral surfaces of the recesses 20 and 20 and the shaft 16 are not deformed, and the outer diameter of each of the rollers 3 is not reduced. The wedge angle α ₁ (α ₂ ) is assumed to be sandwiched between a portion of each of the concave portions 20, 20 near the center in the circumferential direction and a portion of the outer peripheral surface of the shaft 16. >
and α ₁ and) to. Therefore, according to the present invention, the roller 3 sandwiched between the inner peripheral surface of the outer race 15 and the outer peripheral surface of the shaft 16 applies the contact load F applied from the outer race 15 and the shaft 16 to each of the rollers. The size of the recess 3 can be reduced as it approaches one end of the recesses 20 in the circumferential direction. As a result, the rollers 3, the outer ring 15 and the shaft 16 are less likely to be plastically deformed, and the rollers 3 are prevented from being displaced until they come into contact with a part of the respective column portions 19, so that the locked state is ensured. Can be realized. In addition, in the case of the present invention, in order to surely realize the locked state as described above, each of the rollers 3 is required.
, The torque capacity can be sufficiently secured.

In an actual use state, when the roller clutch 1a is used for an application in which a large torque is transmitted between the outer ring 15 and the shaft 16, the outer ring 15 and the shaft When the rollers 16 tend to rotate relative to each other, each of the rollers 3, 3 plastically deforms a part of the outer ring 15 made of synthetic resin,
It is conceivable that it is displaced toward one end in the circumferential direction of zero. When a part of the outer ring 15 is plastically deformed in this manner, the cross-sectional shape of each of the recesses 20 is an arc having a larger radius of curvature than the arc defined as described above. However, the wedge angle α ₂ in a state of being displaced toward the circumferential end of each of the recesses 20 becomes smaller than a predetermined wedge angle α ₂ . However, in the present invention, the predetermined wedge angle α ₂ (= 11 degrees) is changed to the wedge angle (= 9
Degree). Therefore, in order to displace each of the rollers 3 to one end in the circumferential direction of each of the concave portions 20, the amount by which each of the rollers 3 must be elastically deformed is larger than that of the conventional structure. Therefore, when using the roller clutch 1a of the present invention, even if the radius of curvature of the cross section is increased, the wedge angle alpha ₂ which is actually formed, than the wedge angle that is actually formed in the case of the conventional structure If the wedge angle α ₂ is appropriately regulated by making it larger, it is possible to prevent the locked state from being unable to be realized.

In the case of the present embodiment, the wedge angle α ₁ under the condition that the rollers 3 are in contact with the point P is 9 degrees, which is the same as the wedge angle of the conventional structure. Therefore, the locking performance when a relatively small torque is transmitted between the outer ring 15 and the shaft 16 is almost the same as that of the conventional structure.

Next, FIG. 4 shows a second embodiment of the present invention.
An example is shown. In the case of this example, unlike the case of the first example described above, the spur gear 17 (FIG. 1) is provided on the outer peripheral surface of the outer ring 15a.
Instead, a groove 23 is formed at the axially intermediate portion of the outer peripheral surface over the entire circumference. A roller 24 made of an elastic material is fitted on the outer peripheral surface of the groove 23. By engaging the outer peripheral surface of the roller 24 with the outer peripheral surface of a drive shaft (not shown), the rotation of the drive shaft can be transmitted to the outer ring 15a. Because of this,
In the case of this example, the outer peripheral surface of the roller 24 is subjected to grinding, the friction coefficient of the outer peripheral surface is increased, and the engagement between the roller 24 and the drive shaft is ensured. I have. The outer ring 15a is manufactured by injection molding a high-performance resin such as a polyacetal resin.

Further, a pair of flanges 18a, 18a are formed at both axial ends of the inner peripheral surface of the outer ring 15a.
The inner peripheral surfaces of both flanges 18a, 18a are smooth cylindrical surfaces, and the diametric gap between the inner peripheral surface of both flanges 18a, 18a and the outer peripheral surface of shaft 16 is described above. It is smaller than that of the first example. In particular, in the case of this example, the size of the diametral gap is set to 0.01 to
It is set to be about 0.03 mm. The outer ring 15a and the shaft 16 are set so that the roller clutch 1a of the present example is locked.
When the rollers 3 tend to rotate relative to each other in a predetermined direction, each roller 3 does not stretch between the inner peripheral surface of the outer ring 15a and the outer peripheral surface of the shaft 16, and these two peripheral surfaces do not rub against each other.
On the other hand, when the outer ring 15a and the shaft 16 tend to rotate relative to each other in a direction opposite to the predetermined direction so that the roller clutch 1a is in an overrun state, each roller 3 is , 20 are displaced toward the other end in the circumferential direction, and the diametrical gap becomes non-uniform in the circumferential direction. In the overrun state, a part of the inner peripheral surface of the two flanges 18a, 18a in the circumferential direction and a part of the outer peripheral surface of the shaft 16 in the circumferential direction come into sliding contact with each other, so that these two flanges 18a, 18a However, it functions as a slide bearing for supporting the shaft 16. Other configurations and operations are the same as those in the above-described first example, and thus, redundant description will be omitted.

FIG. 5 shows a third embodiment of the present invention.
An example is shown. In the case of the present example, the cross-sectional shape of each of the recesses 20 formed on the inner peripheral surface of the outer ring 15b has an end portion of a first curve 25 having a shape approximating a logarithmic spiral curve, and the first curve 25 Is a composite curve in which the end of the second curve 26 whose curvature is larger than the radius of curvature is smoothly continued. The first curve 25 is defined as follows. First, each of the recesses 20 and 20 and the shaft 16
Are not deformed and the outer diameter of each roller 3 is not reduced, so that each roller 3
0 and 20 are displaced toward one end in the circumferential direction.
A part of the portion 0, 20 near the center in the circumferential direction and the shaft 16
Is assumed to be sandwiched between a part of the outer peripheral surface of the lens. In this state, a straight line connecting the point P where the rolling surface of each roller 3 contacts the inner peripheral surface of the outer ring 15b and the center O of the shaft 16 as viewed in a cross section orthogonal to the axial direction of each roller 3 PO
The point of intersection of a straight line L _A orthogonal to the straight line and a straight line L _B passing through the center S of the roller 3 with the point P is defined as a point Q. And
An arc having the point Q as its center and the length of the straight line PQ as its radius is defined as a first curve 25 which constitutes a portion of the cross-sectional shape of each of the recesses 20, 20 near the center in the circumferential direction.

The second curve 26 is defined as follows. First, a point U located on the straight line QV passing through the point V located at one end in the circumferential direction of the first curve 25 and the point Q is defined. An arc having the point U as its center and the length of the straight line UV as its radius is defined as a second curve 26 that constitutes a portion of the cross-sectional shape of each of the recesses 20, 20 near one end in the circumferential direction. . This second curve 26
And the first curve 25 smoothly continue at the point V. Then, the outer peripheral surfaces of the recesses 20 and 20 and the shaft 16 are not deformed, and the outer diameter of the rollers 3 is reduced, so that the rollers 3 are located near one end of the recesses 20 and 20 in the circumferential direction. the wedge angle alpha ₂ in a portion while assuming sandwiched between a portion of the outer peripheral surface of the shaft 16 (state shown roller 3 by the chain line in FIG. 5) of each recess 20, 2
0 and the outer peripheral surface of the shaft 16 are not deformed, and the outer diameter of each of the rollers 3 is not reduced. The above-described state in a state in which the concave portions 20 and 20 are sandwiched between a part of the center part in the circumferential direction and a part of the outer peripheral surface of the shaft 16 (a state in which the roller 3 is indicated by a solid line in FIG. 5). It is larger than the wedge angle α ₁ (α ₂ > α ₁ ). still,
In the case of this example, the wedge angle α ₁ in a state where the rollers 3 are in contact with each other at the point P is set to 9 degrees, and the outer diameter of each roller 3 is reduced. Each of the pillars 1 provided on a part of the inner peripheral surface of the outer ring 15b is displaced to a position near one end in the circumferential direction of each of the concave portions 20, 20.
The wedge angle α ₂ in a state where it is assumed that a part of 9 and 19 is in contact is set to 12 degrees.

In the case of the present embodiment constructed as described above, the outer ring 15b and the shaft 16 are locked so that the outer ring 15b, the rollers 3 and the shaft 16 have a dimensional error in the diametrical direction so as to be locked. Even in the case where the rollers 3 tend to rotate relative to each other, in a range where the rollers 3 contact the first curve 25,
The contact load applied from the outer ring 15b and the shaft 16 to each of the rollers 3 can be made constant. Other configurations and operations are the same as those in the first example described above, and therefore, duplicate description will be omitted.

In each of the above-described examples, the cam surface is formed on the inner peripheral surface of the outer race, and the outer peripheral surface of the shaft is a cylindrical surface. However, when the peripheral surface forming the cam surface is reversed. Also, the present invention can be applied. That is, in this case, the shaft or the inner ring is made of synthetic resin, a concave portion is formed on the outer peripheral surface of the shaft or the inner ring, the outer peripheral surface is used as the cam surface, and the outer ring is opposed to the cam surface. Is merely a cylindrical surface.

[0034]

Since the roller clutch of the present invention is constructed and operates as described above, it can be manufactured at a low cost and can surely realize the locked state without reducing the torque capacity. .

[Brief description of the drawings]

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

FIG. 2 is an enlarged sectional view taken on line AA of FIG. 1;

FIG. 3 is a schematic diagram showing a relationship between forces applied to the roller in a state where the roller is sandwiched between a concave portion and an outer peripheral surface of a shaft when viewed from the same direction as FIG. 2;

FIG. 4 is a sectional view showing a second example of the embodiment of the present invention.

FIG. 5 is a view similar to FIG. 2, showing a third example.

FIG. 6 is a partial cross-sectional view showing one example of a conventional structure.

FIG. 7 is an enlarged sectional view taken along line BB of FIG. 6;

FIG. 8 is a schematic diagram for explaining the reason why the cross-sectional shape of the concave portion is a curve approximating a logarithmic spiral curve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1a Roller clutch 2 Outer ring 3, 3a, 3b Roller 4 Spring 5 Cage 6 Inner ring 7 Cam surface 8 Depression 9a, 9b Flange part 10 Convex part 11 Pocket 12 Cylindrical gap 13 Holding member 14 Column part 15, 15a, 15c Outer ring 16 Shaft 17 Spur gear 18, 18a Flange 19 Column 20 Recess 21 Cam surface 22 Spring 23 Groove 24 Roller 25 First curve 26 Second curve

Claims (1)

[Claims] 1. An outer ring having a cylindrical inner peripheral surface, an inner member having a cylindrical outer peripheral surface disposed concentrically with the outer ring inside the outer ring, and an inner peripheral surface and an inner member of these outer rings. A concave portion is formed in one circumferential surface of the outer circumferential surface of the outer circumferential surface so as to gradually change the thickness of the gap between the inner circumferential surface of the outer ring and the outer circumferential surface of the inner member in the circumferential direction in the circumferential direction. A plurality of cam surfaces provided by being formed intermittently at a plurality of locations, and a plurality of cam surfaces inserted into portions matching the recesses in a cylindrical gap between the outer peripheral surface of the inner member and the inner peripheral surface of the outer ring. A roller provided between the member provided with the cam surface and each of the rollers, and an elastic member for pressing these rollers in a direction in which the recesses become shallower and pressing them in the same circumferential direction. In the roller clutch, the member provided with the cam surface is made of synthetic resin. Each of the rollers is displaced at one circumferential end of each of the recesses to a side where these recesses are made shallower, and a part of each of the recesses, an inner peripheral surface of the outer ring, and an outer peripheral surface of the inner member. In a state of being sandwiched between a part of the other peripheral surface of the roller and a part of the rolling surface of each roller and the other peripheral surface, as viewed in a cross section orthogonal to the axial direction of each roller. A tangent at the point where the part touches,
When the angle at which the tangent at the point where the rolling surface of each roller contacts a part of each of the recesses is defined as a wedge angle, the recesses and the other peripheral surface are not deformed, and The outer diameter of the rollers is reduced, and the wedge angles under the assumption that these rollers are sandwiched between a part of the concave portion near the one end in the circumferential direction and a part of the other peripheral surface are defined as The respective concave portions and the other peripheral surface are not deformed, and the outer diameter of each of the rollers does not become smaller. A roller clutch, wherein the wedge angle is larger than the wedge angle assuming that the wedge angle is held between a part of the peripheral surface.