JP3740227B2 - One-way clutch - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a one-way clutch using a roller and a coil spring.
[0002]
[Prior art]
In a conventional one-way clutch, if an elastic protrusion that is integrally formed with a leaf spring or a cage is used as an elastic member that urges the roller toward the narrow side of the wedge-shaped space, It is difficult to maintain the power at a constant level, and the absolute magnitude of the impact force is insufficient, making it difficult to improve the operational stability of the one-way clutch. For this reason, a coil spring is used as the elastic member.
[0003]
In the conventional example using this coil spring, the contact position of the coil spring with the roller is set so as to coincide with the center of the coil spring, and the edge of the coil spring is directly contacted with the roller. It is set as follows.
[0004]
[Problems to be solved by the invention]
By the way, the conventional one-way clutch has the following problems and has room for improvement.
[0005]
First, when the contact position of the coil spring with the roller coincides with the center of the center of the coil spring as in the prior art, when the power transmission is switched off, that is, the roller in the wedge-shaped space. When shifting to the idling state, the roller rolls only by the frictional force with the outer ring member, which may cause uneven wear, such as the roller sliding.
[0006]
Secondly, when the edge of the coil spring is brought into direct contact with the roller as in the prior art, the contact area of the edge of the coil spring with respect to the cylindrical outer peripheral surface of the roller is reduced. Depending on how each coil spring is assembled, the contact state of the coil spring edge with the roller tends to be uneven, and the biasing force on each roller may vary, making it difficult to lock and lock all rollers. There is a risk.
[0007]
Accordingly, an object of the present invention is to stabilize the behavior of the rollers and synchronize the locking and free operation of all the rollers in the one-way clutch.
[0008]
[Means for Solving the Problems]
A first one-way clutch according to the present invention is a one-way clutch that switches between a state of transmitting power and a state of interrupting power transmission between an inner ring member and an outer ring member arranged inside and outside in the radial direction , Each of the rollers disposed in the wedge-shaped space provided at the circumferential position in the gap between the inner ring member and the outer ring member has a coil spring that biases toward the narrow side of the wedge-shaped space. The roller is in contact with the axial center position of the roller and a position offset toward the drive member from the roller PCD, and the extension line of the central axis of the coil spring is offset from the rotation center of the roller toward the drive member. .
[0009]
The second one-way clutch of the present invention is a one-way clutch that switches between a state of transmitting power and a state of interrupting power transmission between an inner ring member and an outer ring member arranged inside and outside in the radial direction, A plurality of rollers, a cage having pockets for storing rollers, a cam surface provided in a region corresponding to the pocket on the outer peripheral surface of the inner ring member and forming a wedge-shaped space with the outer ring member; A coil spring that urges toward the narrow side of the wedge-shaped space, and the coil spring is in contact with a center position in the axial direction of the roller and a position offset toward the driving member side with respect to the roller PCD, and the central axis of the coil spring The extension line of is located at a position offset from the rotation center of the roller toward the drive member.
[0010]
A third one-way clutch according to the present invention is a one-way clutch that switches between a state of transmitting power and a state of interrupting power transmission between an inner ring member and an outer ring member arranged inside and outside in the radial direction, A plurality of rollers, a cage having pockets for storing rollers, a cam surface provided in a region corresponding to the pocket on the inner peripheral surface of the outer ring member, and forming a wedge-shaped space with the inner ring member; A coil spring that urges the wedge-shaped space toward the narrow side, the coil spring being in contact with the axial center position of the roller and a position offset toward the drive member side with respect to the roller PCD, and the center of the coil spring The extension line of the shaft is at a position offset from the rotation center of the roller toward the drive member.
[0011]
In addition, it is preferable to interpose a spring receiving member between the above-described coil springs. Further, the spring receiving member is preferably formed such that the end surface on the coil spring side is a flat surface and the end surface on the roller side is a curved surface along the outer peripheral surface of the roller.
[0012]
By the way, as a form of power transmission, there are cases where the inner ring member is driven and the outer ring member is driven, and vice versa. Depending on this form, the drive member described above becomes the inner ring member or the outer ring member. It becomes a member.
[0013]
In the present invention, the elastic urging force of the coil spring can be imparted with good balance in the form of assisting the rolling operation with respect to the roller. As a result, especially when shifting from the power transmission state to the power transmission cutoff state, not only the frictional force from the outer ring member but also the elastic spring biasing force of the coil spring is effectively applied to the roller. The movement of the roller becomes stable, such as smooth movement without slipping while keeping its posture straight.
[0014]
Moreover, if the coil spring is brought into contact with the roller via the spring receiving member, the elastic biasing force of the coil spring applied to all the rollers can be made almost constant regardless of the state of incorporation of the coil spring. The lock and free operations of all rollers are synchronized.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
The details of the present invention will be described based on the embodiment shown in FIGS.
[0016]
1 to 3 relate to one embodiment of the present invention, FIG. 1 is a cross-sectional view of a one-way clutch in a direction orthogonal to the axial direction, and FIG. 2 is a cross-sectional view taken along line (2)-(2) in FIG. FIG. 3 is a developed plan view of a portion surrounded by a circle in FIG.
[0017]
In the figure, A indicates the entire one-way clutch, 1 is a shaft body as an inner ring member, 2 is an outer ring as an outer ring member, 3 is a cage, 4 is a plurality of rollers, 5 is a coil spring, and 6 is a spring. It is a receiving member. Here, the state is switched between a state in which power is transmitted from the shaft body 1 to the outer ring 2 and a state in which power transmission is interrupted. Therefore, the shaft body 1 is a driving member, and the outer ring 2 is a driven member.
[0018]
In the one-way clutch A of this embodiment, the inner peripheral surface of the outer ring 1 is formed in a circular shape, and the cam surface 7 formed of a flat notch along the axial direction is provided at several circumferential positions on the outer peripheral surface of the shaft body 1. Is provided. That is, the cam surface 7 forms a wedge-shaped space with the inner peripheral surface of the outer ring 2. In this way, if the structure in which the cam surface 7 is formed on the outer peripheral surface of the shaft body 1 in the one-way clutch A is adopted, the inner periphery of the outer ring 1 is applied to the rollers 4 even if a rotational centrifugal force is applied. Since only the force pressed against the surface is required, the lock and free operation of the roller 4 can be stably operated. In particular, in a high-speed rotation range where the centrifugal force is large, it is possible to avoid a phenomenon in which some of the rollers 4 are in a free state when all the rollers 4 are in a locked state.
[0019]
The cage 3 is provided with pockets 8 for storing the rollers 4 one by one and recesses 9 for storing the coil springs 5 one by one at the circumferential places. The pocket 8 is formed so as to penetrate inside and outside in the radial direction, and the concave portion 9 opens toward the pocket 8 and one side in the axial direction on the shaft body 1 side serving as a driving member, that is, on the inner diameter side of the cage 3. It is formed as follows.
[0020]
The coil spring 5 is accommodated in the concave portion 9 of the cage 3, and is thereby arranged to be offset toward the shaft body 1, and one end edge of the coil spring 5 is located in the axial center position of the roller 3 via the spring receiving member 6. In addition, the roller 4 is in contact with the position offset from the PCD of the roller 4 toward the shaft body 1 side. By this contact form, the elastic urging force of the coil spring 5 can be imparted to the roller 4 in a well-balanced manner so as to assist the rotation operation.
[0021]
The spring receiving member 6 is interposed between the coil spring 5 and 4, and the end surface on the coil spring 5 side is a flat surface, and the end surface on the roller 4 side is formed on a curved surface along the outer peripheral surface of the roller 4. Has been. The presence of the spring receiving member 6 makes it possible to make the elastic urging force of the coil springs 5 applied to all the rollers 4 almost constant regardless of the state of incorporation of the coil springs 5. In addition, the spring receiving member 6 is made of a synthetic resin material having a low coefficient of friction or a material having self-lubricating property at least at a contact portion with the roller 4. Examples of this material include polyether ether ketone resin, polyacetal resin, and polyamine resin.
[0022]
Next, the operation of the one-way clutch A will be described.
[0023]
(1) In the region where the rotational speed of the shaft body 1 increases, the roller 4 is rolled to the narrow side of the wedge-shaped space and is locked, so that the shaft body 1 and the outer ring 2 are integrated and rotated synchronously. The power is transmitted from the shaft body 1 to the outer ring 2.
[0024]
(2) When the rotational speed of the shaft body 1 becomes lower than that of the outer ring 2 in the region where the rotational speed of the shaft body 1 is lowered, the rollers 4 are rolled to the wide side of the wedge-shaped space and become free. The transmission of rotational power from the body 1 to the outer ring 2 is cut off, so that the outer ring 2 rotates only by the rotational inertia force.
[0025]
(3) When the rotational speed difference between the shaft body 1 and the outer ring 2 disappears in the process of increasing or decreasing the rotational speed of the shaft body 1, the roller 4 is rolled to the narrow side of the wedge-shaped space and becomes locked. Thus, the shaft body 1 and the outer ring 2 are integrated and rotated synchronously.
[0026]
In such an operation, the characteristic configuration of this embodiment makes it possible to smoothly and appropriately switch between the power transmission state and the power transmission interruption state. In other words, the elastic biasing force of the coil spring 5 can be imparted to the roller 4 in a balanced manner so as to assist the rolling operation. On the other hand, not only the frictional force from the outer ring 2 but also the elastic urging force of the coil spring 5 is efficiently applied, so that the rolling operation of the roller 4 can be smoothly performed without slipping while keeping its posture straight. For example, the behavior of the roller 4 is stabilized. Further, by bringing the coil spring 5 into contact with the roller 4 via the spring receiving member 6, the elastic urging force of the coil spring 5 applied to all the rollers 4 is made substantially constant regardless of the assembled state of the coil spring 5. Since this is possible, the lock and free operations of all the rollers 4 are synchronized.
[0027]
In addition, this invention is not limited only to the said Example, Various application and deformation | transformation can be considered.
[0028]
(1) In the above embodiment, the shaft 1 is used as a driving member and the outer ring 2 is used as a driven member. In the opposite case, as shown in FIG. What is necessary is just to make it contact | abut to the position which shifted to the outer ring | wheel 2 side rather than 4 PCD. Also in this case, the same operation and effect as in the above embodiment can be obtained.
[0029]
(2) In the above embodiment, the one-way clutch A in which the cam surface 7 is formed on the outer peripheral surface of the shaft body 1 is taken as an example. However, as shown in FIGS. The present invention can also be applied to the one-way clutch A of the type formed on the inner peripheral surface of the outer ring 2. In this embodiment, the configuration different from the above-described embodiment is that the cam surface 7 is formed at a number of circumferential positions on the inner peripheral surface of the outer ring 2, and the other configurations are basically the same. 5 is a case where the shaft body 1 is a drive member and the outer ring 2 is a driven member, and the structure of FIG. 6 is a case where the outer ring 2 is a drive member and the shaft body 1 is a driven member. Yes, the contact state of the coil spring 5 with the roller 4 is different. In these cases, substantially the same operations and effects as in the above embodiment can be obtained.
[0030]
(3) In each of the above embodiments, the end face shape of the spring receiving member 6 on the roller 4 side is formed on a curved surface corresponding to the outer peripheral surface of the roller 4, but this shape is, for example, a flat slope. Can do.
[0031]
【The invention's effect】
According to the first to third aspects of the invention, the elastic spring biasing force of the coil spring can be imparted to the roller in a balanced manner by devising the contact position of the coil spring with the roller. The roller behavior can be stabilized such that the roller is smooth without slipping while keeping its posture straight no matter where the roller is located in the wedge-shaped space. Therefore, it becomes possible to contribute to improving the reliability of the one-way clutch.
[0032]
In particular, in the invention of claim 2, since the cam surface forming the wedge-shaped space is formed on the outer peripheral surface of the inner ring member, the rotational centrifugal force acts on the roller so that the roller is in the inner periphery of the outer ring. Even when pressed against the surface, the roller position does not change. For this reason, in a high-speed rotation range where the centrifugal force is large, reliability is improved, such as a phenomenon that some rollers are in a free state when all the rollers are locked. become.
[0033]
In the inventions of claims 4 and 5, since the coil spring is brought into contact with the rollers via the spring receiving member, the elastic urging force of the coil spring applied to all the rollers can be made substantially constant. Therefore, it is possible to synchronize the locking and free operation of all the rollers, contributing to the stabilization of the operation of the one-way clutch.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a one-way clutch in a direction perpendicular to the axial direction according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line (2)-(2) in FIG. 2 is a plan development view of a portion surrounded by a circle in FIG. 2. FIG. 4 is a diagram corresponding to FIG. 1 in another embodiment of the present invention. FIG. 5 is a diagram corresponding to FIG. 6 is a diagram corresponding to FIG. 1 in another embodiment of the present invention.
A One-way clutch 1 Shaft body 2 Outer ring 3 Cage 4 Roller 5 Coil spring 6 Spring receiving member 7 Cam surface 8 Cage pocket 9 Cage recess

Claims (5)

A one-way clutch that switches between a state in which power is transmitted and a state in which power transmission is interrupted between an inner ring member and an outer ring member disposed inside and outside in the radial direction,
A coil spring that urges each roller disposed in a wedge-shaped space provided at several circumferential positions in the gap between the inner ring member and the outer ring member to bias the wedge-shaped space to a narrower side;
The coil spring is in contact with the axial center position of the roller and a position offset toward the drive member side from the roller PCD .
A one-way clutch characterized in that an extension line of a central axis of a coil spring is in a position offset toward a driving member side with respect to a rotation center of a roller . A one-way clutch that switches between a state in which power is transmitted and a state in which power transmission is interrupted between an inner ring member and an outer ring member disposed inside and outside in the radial direction,
A plurality of rollers, a cage having pockets for storing rollers, a cam surface provided in a region corresponding to the pocket on the outer peripheral surface of the inner ring member and forming a wedge-shaped space with the outer ring member; A coil spring that biases toward the narrow side of the wedge-shaped space,
The coil spring is in contact with the axial center position of the roller and a position offset toward the drive member side from the roller PCD ,
A one-way clutch characterized in that an extension line of a central axis of a coil spring is in a position offset toward a driving member side with respect to a rotation center of a roller . A one-way clutch that switches between a state in which power is transmitted and a state in which power transmission is interrupted between an inner ring member and an outer ring member disposed inside and outside in the radial direction,
A plurality of rollers, a cage having pockets for storing rollers, a cam surface provided in a region corresponding to the pocket on the inner peripheral surface of the outer ring member, and forming a wedge-shaped space with the inner ring member; A coil spring that urges the wedge-shaped space toward the narrow side,
The coil spring is in contact with the axial center position of the roller and a position offset toward the drive member side from the roller PCD ,
A one-way clutch characterized in that an extension line of a central axis of a coil spring is in a position offset toward a driving member side with respect to a rotation center of a roller .   The one-way clutch according to any one of claims 1 to 3, wherein a spring receiving member is interposed between the coil spring and the coil spring.   The one-way clutch according to claim 4, wherein the end surface on the coil spring side of the spring receiving member is formed as a flat surface, and the end surface on the roller side is formed as a curved surface along the outer peripheral surface of the roller.

Images