JP3795221B2 - One-way clutch - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a one-way clutch. This one-way clutch is incorporated in a crank pulley of an engine such as an automobile, a pulley provided in an auxiliary machine driven via a belt from a crank shaft, in addition to a feed mechanism of various functional devices. Examples of the auxiliary machine include a compressor for an air conditioner of a car, a water pump, an alternator, and a cooling fan.
[0002]
[Prior art]
In the conventional one-way clutch, pockets having a rectangular shape in plan view are provided at several locations around the circumference of the cage so as to penetrate the inside and outside in the radial direction, and a roller and a coil spring that elastically biases the roller toward the lock side are provided in the pocket. Stored.
[0003]
The coil spring is housed in a compressed state, and elastically biases the roller with its extension restoring force. As this coil spring, a general one in which a spring wire is wound into a cylindrical shape is used, and is in contact with an intermediate region in the axial direction of the roller.
[0004]
[Problems to be solved by the invention]
By the way, the contact form with the coil spring is such that the end winding portion on one end side in the expansion / contraction direction of the coil spring is brought into contact with the roller circumferential surface at two places in the length direction (axial direction). As this coil spring, a commercially available cylindrical one is usually used, and such a coil spring is usually spiral and each winding portion is inclined without being orthogonal to the expansion and contraction direction. Therefore, the elastic urging force of the coil spring acting at two places in the length direction (axial direction) of the roller may become uneven, and a skew force may be given to the roller. By the way, if the roller receives a skew force, the lock and free operation tends to become unstable, such as the posture of the roller tilting.
[0005]
In addition, since the coil spring is in direct contact with the roller, it is pointed out that the contact portion of the coil spring in the roller is easily damaged over time.
[0006]
Accordingly, an object of the present invention is to maintain a stable posture of a roller and stabilize a clutch operation in a one-way clutch.
[0007]
[Means for Solving the Problems]
The one-way clutch of the invention of claim 1 is a one-way clutch that switches between a locked state in which two inner and outer rings arranged concentrically are rotated synchronously and a free state in which the inner and outer rings are rotated relative to each other. A retainer having pockets penetrating inward and outward in the radial direction at several circumferential positions corresponding to wedge-shaped spaces disposed in the radially opposed space of the ring body and disposed at several circumferential positions in the radially opposed space; A plurality of rollers stored in each pocket so as to be able to roll in the circumferential direction; a plurality of coil springs stored in a compressed state in each pocket of the cage; and a plurality of coil springs for elastically urging each roller toward the lock side by an extension restoring force; and a plurality of pressing members to be imparted almost evenly distributed each elastic urging force of the interposed and having a coil spring in the axial direction of the roller between the rollers and the coil springs, the pressing member The belt plate having substantially the same size as the effective track region of the roller and contacting the roller, and a leg portion integrally formed on the back surface side of the belt plate portion and fitted into the inner periphery of the coil spring, and the holding A guide projection is provided on the inner wall surface on one side in the circumferential direction of the pocket of the vessel, and the guide spring protrudes along the expansion and contraction direction of the coil spring. The coil spring is engaged in a state in which the sliding amount to the side is regulated, and the coil spring is externally enclosed so as to surround the guide protrusion and the leg portion, and both ends of the coil spring in the expansion / contraction direction are held on the back surface of the band plate portion. The container is in contact with an inner wall surface on which guide protrusions are formed .
[0011]
The one-way clutch of the invention of claim 2, Oite to the claim 1, abutment surface roller of the strip portion of the pressing member is formed on the concave surface along the outer peripheral surface of the roller.
[0012]
As described above, in the present invention, in short, the coil spring is not brought into direct contact with the roller, but is indirectly brought into contact with the pressing member. And also about a holding | suppressing member, it is set as the thing which does not make the elastic urging | biasing force of a coil spring the skew force with respect to a roller.
[0013]
In particular, since the holding member has a leg portion, when the roller rolls to the free state side and compresses the coil spring, the leg portion of the holding member abuts against the inner wall surface of the cage pocket, thereby compressing the coil spring. The amount will be regulated. Thereby, it becomes possible to avoid that each winding part of a coil spring collides.
[0014]
The slide of the pressed pressing member since guided by the guide protrusions, it becomes possible to stabilize the movement of the pressing member.
[0015]
Also, it becomes possible to prevent the displacement in the vertical and horizontal directions of the coil spring by pressing even member and the guide protrusion. Thereby, the buckling of the coil spring can be prevented.
[0016]
In the invention of claim 2 , the contact area with the pressing member is further increased, and the contact pressure can be reduced as much as possible.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
The details of the present invention will be described based on the embodiment shown in FIGS.
[0018]
1 to 5 relate to one embodiment of the present invention, FIG. 1 is a side view in which the upper half of the one-way clutch is sectioned, and FIG. 2 is an arrow of a section taken along line (2)-(2) in FIG. FIG. 3 is a developed plan view of the pocket portion of the cage, FIG. 4 is an exploded perspective view showing the cage and a coil spring, and FIG. 5 is a perspective view of the slider alone.
[0019]
In the figure, A indicates the entire one-way clutch. The one-way clutch A includes an inner ring 1, an outer ring 2, a cage 3, rollers 4, and a coil spring 5. In terms of operation, depending on the rotational speed difference between the inner ring 1 and the outer ring 2, the roller 4 rolls and the inner / outer rings 1 and 2 are synchronously rotated to transmit power, or relatively rotated to transmit power. It is designed to switch to the shut-off state.
[0020]
Hereafter, each said component is demonstrated in detail.
[0021]
The inner ring 1 is provided with cam surfaces 6 formed of flat key-shaped notches at several locations on the inner peripheral surface. Slit-like notches 1a and 1a are provided at two locations on one end face of the inner ring 1 facing each other at 180 degrees.
[0022]
The outer ring 2 is formed in a cylindrical shape on both the inner and outer peripheral surfaces, and is disposed concentrically on the outer periphery of the inner ring 1 via a required facing space. A wedge-shaped space is formed by the inner peripheral surface of the outer ring 2 and the cam surface 6 of the inner ring 1.
[0023]
The cage 3 is provided with a pocket 3 a penetrating radially inward and outward at a position corresponding to the cam surface 6 of the inner ring 1. Projecting pieces 3b, 3b press-fitted into the notches 1a, 1a of the inner ring 1 are provided at two locations facing each other by 180 degrees on one axial side surface of the pocket 3a of the cage 3. The cage 3 is positioned in the circumferential direction and the axial direction with respect to the inner ring 1 by fitting the protrusions 3b, 3b to the notches 1a, 1a.
[0024]
The rollers 4 are accommodated in a wedge-shaped space formed between the cam surface 6 of the inner ring 1 and the inner peripheral surface of the outer ring 2 in a state in which the rollers 4 are housed in the pockets 3a of the cage 3 so as to be capable of rolling in the circumferential direction. Has been placed.
[0025]
One coil spring 5 is housed in each pocket 3a of the cage 3 in a compressed state, and elastically urges the rollers 4 toward the narrow side (lock side) of the wedge-shaped space by its expansion restoring force. The coil spring 5 is formed of a square spring wound in a rectangular tube having a substantially rectangular shape when viewed from the side. In the pocket 3 a of the cage 3, the expansion and contraction direction is perpendicular to the central axis of the roller 4 and one end side is the roller 4. Is applied to a length range of ½ or more of the axial length dimension of the roller 4, for example, 2/3.
[0026]
Next, features of the present invention will be described. By interposing the pressing member 7 between the roller 4 and the coil spring 5, the elastic biasing force of the coil spring 5 is indirectly applied via the pressing member 7 without causing the coil spring 5 to directly contact the roller 4. It is given to roller 4. The pressing member 7 is held in a pocket 3 a of the cage 3 in a state that allows a required amount of movement in a direction orthogonal to the axial direction of the rollers 4.
[0027]
Specifically, as shown in FIG. 5, the pressing member 7 includes a strip plate portion 7a having substantially the same size as the effective track region of the roller 4, and a pair of left and right legs integrally formed on the back side of the strip plate portion 7a. 7b, which is manufactured by molding a synthetic resin material, for example.
[0028]
The band plate portion 7a is formed in a rectangular shape having the same dimensions as the effective track area of the roller 4, and the front surface thereof has the same curvature as the shape of the outer peripheral surface of the roller 4, that is, the curvature of the roller 4, or slightly larger than this. The concave curved surface s has a curvature. Thereby, the contact area of the pressing member 7 with respect to the roller 4 becomes as large as possible.
[0029]
The pair of leg portions 7b are engaged with guide protrusions 3c provided on the inner wall surface at one end in the circumferential direction of the pocket 3a of the cage 3 in such a manner as to be sandwiched from both sides. In a state where the leg portions 7b are engaged with the guide projections 3c, the coil spring 5 is externally enclosed so as to surround them, so that the coil spring 5 is compressed between the inner wall surface of the pocket 3a and the back surface of the belt plate portion 7a. It will be retained. Since the pressing member 7 is elastically biased toward the roller 4 by the expansion restoring force of the coil spring 5 in the compressed state, the concave curved surface s of the band plate portion 7 a of the pressing member 7 is pressed against the outer peripheral surface of the roller 4. It is done. Further, according to this configuration, the postures of the pressing member 7 and the coil spring 5 are positioned in the vertical and horizontal directions, so that the contact position of the pressing member 7 with respect to the roller 1 does not shift even when subjected to vibration or impact.
[0030]
Further, a step portion 3d is provided on the left and right side surfaces of the guide protrusion 3c of the retainer 3, and on the other hand, a protrusion 7c is provided on the inner surface of the free end of the leg portion 7b of the pressing member 7, and the step portion 3d is provided with this step portion 3d. On the other hand, the forward movement amount of the pressing member 7 is regulated by the projection 7c being hooked. The retreating movement of the pressing member 7 is regulated by the contact between the free end of the leg portion 7b of the pressing member 7 and the inner wall surface of the pocket 3a. By restricting the backward movement, the amount of compression of the coil spring 5 is restricted, and the winding portions of the coil spring 5 are prevented from coming into close contact with each other.
[0031]
If such a pressing member 7 is used, the concave curved surface s of the band plate portion 7a of the pressing member 7 can be brought into contact with the roller 4 in a wide and large contact area in the axial direction. Regardless of the shape, the elastic urging force of the coil spring 5 can be distributed evenly over substantially the entire axial direction of the roller 4. In other words, it is not necessary to give the roller 4 a skew force.
[0032]
In addition, as in this embodiment, if the coil spring 5 is a square spring and the both ends in the longitudinal direction of the band plate portion 7a of the pressing member 7 are pressed, the elastic urging force of the coil spring 5 is applied to the roller 4. It becomes easy to disperse and apply to almost the whole area in the axial direction.
[0033]
As a result, the elastic urging force of the coil spring 5 can always be imparted to the roller 4 in a well-balanced manner, so that the roller 4 can be smoothly rolled while maintaining an appropriate posture. Can be prevented, and it becomes possible to contribute to the stabilization of the lock and free operation by the roller 4.
[0034]
In addition, this invention is not limited only to the said embodiment, Various application and deformation | transformation can be considered.
[0035]
(1) As shown in FIGS. 6 and 7, the leg portion 7 b of the pressing member 7 shown in the above embodiment can be formed in a hollow prismatic shape or a substantially U shape in a side view. In this case, the guide protrusion 3c provided on the cage 3 may be formed in a simple prismatic shape, and the leg portion 7b of the pressing member 7 may be inserted.
[0036]
(2) The leg portion 7b of the pressing member 7 and the guide protrusion 3c of the retainer 3 shown in the above embodiment may be provided in an inverse relationship to each other as shown in FIGS. That is, in the illustrated example, the holding member 7 is formed with one hollow prismatic leg portion 7b, and the cage 3 is formed with a pair of guide protrusions 3c that sandwich the leg portion 7b from the left and right. Has been. These engagement forms are the same as those in the above-described embodiment.
[0037]
(3) In the above embodiment, an example in which the cam surface 6 is formed on the inner ring 1 side is given, but the present invention can also be applied to those provided on the outer ring 2 side. The cam surface 6 is not limited to a flat shape, and may be a curved surface.
[0038]
(4) In the above embodiment, the coil spring 4 is a square spring, but a general one wound in an elliptical shape or a circular shape can also be used.
[0039]
(5) The front surface shape of the band plate portion 7a of the pressing member 7 in the above embodiment may be formed in a flat plane or in a V shape.
[0040]
(6) The material of the cage 2 and the pressing member 7 is not particularly limited, but can be easily and inexpensively manufactured by molding with synthetic resin. In particular, if the pressing member 7 is formed of a resin having a material excellent in lubricity or a resin material mixed with a lubrication material, the rolling of the roller 4 is smoothed and the roller 4 is more effectively prevented from being damaged.
[0041]
(7) The one-way clutch A can be incorporated in pulleys of various auxiliary machines that are mounted on engines such as automobiles. Specifically, the case where an alternator is used as an auxiliary machine will be described with reference to FIG. In this case, the one-way clutch A of the above-described embodiment is interposed between the pulley 20 and the rotor 21 of the alternator, and rolling bearings 22 and 22 such as deep groove ball bearings are provided on both axial sides of the one-way clutch A. It is arranged. In this case, the one-way clutch A is switched between the free state and the locked state in accordance with the difference in rotational speed between the pulley 20 and the rotor 21, and the rotational power is transmitted from the pulley 20 to the rotor 21 or blocked. . In the alternator, since the pulley 20 is rotationally driven by the engine crankshaft via the belt 23, conventionally, for example, when the rotation speed of the crankshaft decreases, the power generation efficiency of the alternator decreases, but the one-way clutch If A is built in, when the rotational speed of the pulley 20 decreases, the one-way clutch A can function so that the rotor 21 maintains the rotational speed at a high frequency by its own inertial force. You can contribute to the improvement.
[0042]
【The invention's effect】
The invention according to claim 1 or 2 contributes to the improvement of reliability, such as being able to roll smoothly while keeping the roller in an appropriate posture, and contributing to the stabilization of the lock and free operation by the roller. it can. Moreover, since it becomes possible to prevent the roller from being damaged by the coil spring, it is possible to contribute to the improvement of the durability of the roller.
[0043]
In particular, since the holding member has a leg portion, when the roller rolls to the free state side and compresses the coil spring, the leg portion of the holding member abuts against the inner wall surface of the cage pocket, thereby compressing the coil spring. The amount will be regulated. Thereby, it becomes possible to avoid that each winding part of a coil spring collides, and it can contribute to the durable improvement of a coil spring.
[0044]
Also, since the press even slide member is guided by the guide protrusion, able to stabilize the movement of the pressing member, it becomes possible to impart a more stable elastic urging force against the roller.
[0045]
Also, since it becomes possible to prevent the displacement in the vertical and horizontal directions of the coil spring by pressing even member and the guide protrusions, it will be able to prevent the buckling of the coil spring, so that it can prevent the unlocking of the emergency rollers Become.
[0046]
Further, in the invention of claim 2 , since the contact area with the pressing member is further increased, the contact pressure can be reduced as much as possible, and the durability can be improved.
[Brief description of the drawings]
FIG. 1 is a side view in which the upper half of a one-way clutch according to an embodiment of the present invention is sectioned. FIG. 2 is a sectional view taken along line (2)-(2) in FIG. FIG. 4 is an exploded perspective view showing a cage, a coil spring, and the like. FIG. 5 is a perspective view of a holding member alone. FIG. 6 is a diagram corresponding to FIG. Fig. 8 is a diagram corresponding to Fig. 5 in another embodiment of the present invention. Fig. 8 is a diagram corresponding to Fig. 3 in another embodiment of the present invention. Fig. 9 is a diagram corresponding to Fig. 5 in another embodiment of the present invention. 10 is a sectional view showing the upper half of the pulley unit incorporating the one-way clutch shown in FIG.
A One-way clutch 1 Inner ring 2 Outer ring 3 Retainer 3a Retainer pocket 3c Retainer guide protrusion 4 Roller 5 Coil spring 7 Retaining member 7a Retaining member strip 7b Retaining member leg

Claims (2)

A one-way clutch that switches between a locked state in which two inner and outer rings arranged concentrically are rotated synchronously and a free state in which the two rings are rotated relative to each other, and is disposed in a radially opposing space between the two inner and outer rings. And a cage having pockets penetrating inward and outward in the radial direction at circumferential locations corresponding to wedge-shaped spaces provided at several circumferential locations in the radially opposed space, and accommodated in the respective pockets of the cage so as to be able to roll in the circumferential direction. A plurality of rollers, a plurality of coil springs that are housed in a compressed state in the respective pockets of the cage, and that elastically urge each roller toward the lock side by an extension restoring force, and each roller is interposed between each coil spring and each coil spring. A plurality of pressing members mounted and applied to distribute and apply the elastic urging force of the coil spring almost uniformly in the axial direction of the rollers ,
The pressing member has a strip plate portion that is substantially the same size as the effective track region of the roller and contacts the roller, and a leg portion that is integrally formed on the back side of the strip plate portion and that fits into the inner periphery of the coil spring. Yes,
A guide projection is provided on the inner wall surface on one side in the circumferential direction of the pocket of the cage, and the guide spring protrudes along the expansion and contraction direction of the coil spring. And the sliding amount to the roller side is engaged in a regulated state,
The coil spring is packaged so as to surround the guide protrusion and the leg portion, and both ends of the coil spring in the expansion / contraction direction are in contact with the back surface of the band plate portion and the inner wall surface on which the guide protrusion is formed in the cage. ,
A one-way clutch characterized by that. 2. The one-way clutch according to claim 1 , wherein a roller contact surface of a band plate portion of the pressing member is formed as a concave curved surface along an outer peripheral surface of the roller.

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