JP5041328B2 - One-way clutch and manufacturing method thereof - Google Patents

Description

The present invention is a one-way clutch and relates its manufacturing process, the one-way clutch comprising in particular arranged to bias in one direction the wedge member by a biasing member disposed to the cage between the outer ring and the inner ring thereof It relates to a manufacturing method .

The one-way clutch is built in, for example, a pulley unit provided in an engine accessory driven from a crankshaft of an engine such as an automobile via a belt. Examples of the engine auxiliary machine include a compressor for an air conditioner of a car, a water pump, an alternator, a cooling fan, and a crank pulley.

In order to prevent belt squeal and flutter due to engine rotation fluctuation, the alternator needs a rotation fluctuation absorption mechanism. As a conventional rotational fluctuation absorbing mechanism, a one-way clutch type or a spring type is used. For example, a one-way clutch type rotational fluctuation absorbing mechanism has a structure in which a one-way clutch and a support bearing are arranged between a shaft and a pulley (see, for example, Patent Document 1).

The one-way clutch includes an inner ring, a cage, an urging member, an engaging roller, and a shell outer ring (a thin outer ring like a shell having a raceway surface formed by precision drawing from a thin steel plate). Some are composed. The shell outer ring has flanges at both end openings, and the assembly including the cage, the urging member, and the engaging rollers is prevented from coming off by the both flanges. Hereinafter, when the one-way clutch has a shell outer ring, the one-way clutch has a shell structure.
Japanese Patent Laying-Open No. 2005-256884 (FIG. 1, paragraph 0014)

In a one-way clutch having a conventional shell structure, a shell outer ring whose one flange is flush with the outer peripheral surface (hereinafter referred to as a front shell outer ring) is prepared in advance. It was necessary to assemble a one-way clutch by press-fitting an assembly including a cage, a biasing member, and engaging rollers, and then bending one of the flange portions of the outer shell outer ring. For this reason, there is a problem that the cost is increased due to the bending process of the shell outer ring.

Further, in the one-way clutch having the conventional shell structure, it is necessary to anneal one flange portion of the outer shell outer ring to a hardness that allows bending work for bending. For this reason, there has been a problem of high costs due to the annealing process of the outer shell outer ring.

An object of the present invention is to provide a one-way clutch in which both outer flange portions of an outer ring are formed in advance and do not perform rear bending of the flange portion, and a method for manufacturing the same.

Means for Solving the Problems and Effects of the Invention

The one-way clutch according to claim 1 is a one-way clutch in which a wedge member is urged in one direction by a urging member on a cage disposed between an outer ring and an inner ring. Is a shell outer ring having flanges on both sides, and the cage is formed to be C-shaped in a natural state , and elastically until its outer diameter is smaller than the inner diameter of the flange of the shell outer ring. It is possible to reduce the diameter and apply a force from the outer peripheral side to the retainer to form a small diameter state in which both end portions overlap each other, and this small diameter retainer is formed by the inner peripheral edge of one flange portion of the shell outer ring. The cage is assembled to the shell outer ring by inserting from the formed opening and removing the force applied from the outer peripheral side to the cage to expand the diameter . According to the one-way clutch according to claim 1, the outer ring of the retainer is contracted from the inner diameter of the flange portion of the outer ring by utilizing the elastic deformation of the retainer, so that the retainer can be It becomes possible to assemble to. This eliminates the need for an outer ring bending process and an annealing process, thereby realizing a significant cost reduction.
According to the method of manufacturing a one-way clutch corresponding to this, the wedge member is urged in one direction by the urging member on the cage disposed between the outer ring and the inner ring. In the one-way clutch manufacturing method, the outer ring is a shell outer ring having flanges on both sides, and the cage is formed so as to be C-shaped in a natural state. Applying force, the two ends overlap each other in a small diameter state, and the small diameter retainer is inserted from the opening formed by the inner peripheral edge of one flange of the shell outer ring, The cage is assembled to the shell outer ring by removing the force applied from the side and expanding the diameter.

The one-way clutch according to claim 2 is the one-way clutch according to claim 1, wherein a triangular protrusion is formed on the inner peripheral surface of the cage as a restricted portion that is hooked on a ramp surface that constitutes a cam surface of the inner ring. The angle formed by the outer peripheral surface of the inner ring and the ramp surface and the angle formed by the inner peripheral surface of the cage and the engagement surface of the triangular protrusion are both set to acute angles . According to the one-way clutch of the second aspect, the restricted portion that is hooked on the cam surface of the inner ring is formed on the inner peripheral surface of the cage, thereby restricting the cage from moving in the circumferential direction of the inner ring. be able to.

A one-way clutch according to a third aspect is the one-way clutch according to the first or second aspect, wherein the wedge member is an engaging roller. According to the one-way clutch described in claim 3, since the wedge member is the engaging roller, the shell outer ring and the engaging roller are in line contact with each other, and sufficient strength can be maintained even with the shell outer ring. it can. However, it is sufficient for the outer ring to have both flange portions formed in advance, and the outer ring is not limited to the shell outer ring.

The one-way clutch according to claim 4 is the latched in the one-way clutch according to any one of claims 1 to 3, the hook portion at one end of the retainer, the other end of said retainer the section provided, wherein the retainer in the state in which the hook portion is hooked to the the latched portion was prevented from being enlarged. According to the one-way clutch according to claim 4, the engaging portion since the cage while hooked to the holding portion is prevented from enlarged, the hook portion of the retainer after assembled to the outer ring to be By latching on the latching portion, it is possible to prevent a problem that the diameter of the cage expands due to centrifugal force, contacts the outer ring, and wears the outer ring.

The object of eliminating the need for post-bending of the outer ring collar was achieved by forming the cage in a C shape.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a side sectional view of a pulley unit 10 in which a one-way clutch 13 according to a first embodiment of the present invention is disposed. The pulley unit 10 is, for example, disposed between a crankshaft (not shown) of an automobile engine and an alternator that is an engine accessory, and a sleeve 11 fixed to a rotor shaft (not shown) of the alternator. A pulley 12 is provided on the radially outer side of the sleeve 11 so as to be concentric with the sleeve 11 and formed with a belt groove 12a on the outer peripheral surface. A drive belt (not shown) suspended from a crank pulley (not shown) fixed to the crankshaft of the engine is stretched over the belt groove 12a, and the engine and the alternator are mechanically connected via the drive belt. It is connected to.

A one-way clutch 13 is disposed between the outer peripheral surface of the sleeve 11 in the axial intermediate portion and the inner peripheral surface of the pulley 12 in the axial intermediate portion.

A pair of ball bearings 14, 14, which are a pair of support bearings, are sandwiched between an outer peripheral surface at both axial end portions of the sleeve 11 and an inner peripheral surface at both axial end portions of the pulley 12. It is arranged. The ball bearings 14 and 14 enable the relative rotation of the sleeve 11 and the pulley 12 while supporting a radial load applied to the pulley 12.

The one-way clutch 13 is press-fitted and fixed to the outer peripheral surface of the sleeve 11, and an inner ring 15 that rotates together with the sleeve 11, and a shell that is press-fitted and fixed to the inner peripheral surface of the pulley 12 so as to be concentric with the inner ring 15 and rotates together with the pulley 12. The outer ring 16, a plurality of engagement rollers 23 that are wedge members disposed in a wedge-shaped space 19 (see FIG. 2) between the inner ring 15 and the shell outer ring 16, and each engagement roller 23 are individually accommodated. A retainer 24 having a plurality of pockets 24a (see FIG. 2) and a plurality of leaf springs 25 (see FIG. 2) which are fixed to the retainer 24 and are urging members that urge the engagement rollers 23 in the locking direction. ).

The inner ring 15 is made of a carbon steel such as S45C or S55C, or a case-hardened steel such as SCR, SCM or SNCM in a cylindrical shape, and its outer circumferential surface has a circumferential direction as shown in FIG. Eight cam surfaces 17 are formed at equal intervals. That is, the inner ring 15 is provided with four pairs of cam surfaces 17, 17 facing each other across the rotation center axis line in the circumferential direction. The cam surface 17 includes a ramp surface 20 that gradually increases in depth from one circumferential end portion thereof, and a groove surface 22 that extends from the other circumferential end portion of the cam surface 17 serving as the heel portion 21 toward the ramp surface 20. Formed from.

The shell outer ring 16 is a relatively thin cylindrical body formed by precision drawing from a thin steel plate, and flanges 16a and 16a are formed at both ends thereof. The inner peripheral engagement surface 18 that is the inner peripheral surface of the shell outer ring 16 is subjected to a hardening process by carburizing, carbonitriding, or induction hardening.

The engaging roller 23 is made of a steel cylindrical body, and is disposed in a pocket 24 a that is a space formed in the retainer 24 while being urged in the circumferential direction by a leaf spring 25. In other words, the engaging roller 23 is rotatably disposed in each wedge-shaped space 19 formed by the cam surface 17 provided on the outer peripheral surface of the inner ring 15 and the inner peripheral engaging surface 18 of the outer ring 16. Has been.

The cage 24 is formed in a C shape by a synthetic resin and has an outer peripheral shape substantially along the inner peripheral engagement surface 18 of the outer ring 16 and an inner peripheral shape along the cam surface 17 of the inner ring 15. The outer ring 16 is housed and arranged. A slight gap is provided between the outer peripheral surface of the cage 24 and the inner peripheral engagement surface 18 of the outer ring 16.

As shown in FIG. 3, the retainer 24 includes a pair of rim portions 26, 26 and a plurality of column portions 27 that connect the pair of rim portions 26, 26. As shown in FIG. 4, triangular protrusions 24b that engage with the ramp surface 20 of the cam surface 17 are formed on the inner peripheral surfaces of the pair of rim portions 26, 26. As shown in FIG. After 24 is assembled to the shell outer ring 16, the triangular protrusion 24 b comes into contact with the ramp surface 20, whereby the relative rotation of the cage 24 with respect to the inner ring 15 is restricted. The angle θ formed by the outer peripheral surface of the inner ring 15 and the ramp surface 20 and the angle ω formed by the inner peripheral surface of the cage 24 and the engagement surface (the left side surface as viewed in FIG. 6) of the triangular protrusion 24b. By setting the acute angle to 90 degrees or less, not only the relative rotation of the cage 24 with respect to the inner ring 15 can be regulated, but also the diameter expansion of the C-shaped cage 24 can be regulated simultaneously.

Further, the retainer 24 has end-side spring holding portions 29 and 29 on the inner surfaces of the pair of rim portions 26 and 26 in the circumferential direction and the outer peripheral surfaces of the column portions 27. It is formed in a state protruding from the side outward in the circumferential direction. On the other hand, the center side spring holding part 30 which is a roller restricting part is formed in the axial direction center part of each pillar part 27 in a state protruding from the outer peripheral surface side of each pillar part 27 in the circumferential direction. ing. The end-side spring holding portions 29 and 29 and the center-side spring holding portion 30 are arranged in a slightly shifted state in the circumferential direction, and the leaf spring 25 is arranged with respect to the end-side spring holding portions 29 and 29. It is sandwiched between one side surface in the circumferential direction and the other side surface in the circumferential direction of the central spring holding portion 30. The thickness t in the circumferential direction of the center side spring holding part 30 is such that when the engaging roller 23 crushes the leaf spring 25 to a predetermined deflection amount or more, one end face 30a in the circumferential direction of the center side spring holding part 30. Is set to abut. Further, the length of the pressing portion 32 of the leaf spring 25 is set so as not to interfere with the central spring holding portion 30 when the engaging roller 23 comes into contact with one circumferential end surface 30a of the central spring holding portion 30. Has been.

The leaf spring 25 is formed by bending an elastic metal piece. That is, the pressing portion 32 is configured by bending the predetermined position as the bent portion 31, and the abutting portion 33 is configured by further bending the distal end portion of the pressing portion 32. Accordingly, the leaf spring 25 urges each engaging roller 23 in the locking direction, that is, toward the shallow side of the groove of the cam surface 17.

As a manufacturing method of the retainer 24, an annular front retainer may be manufactured, and then one part of the front retainer may be cut to form a C-shaped retainer 24. Also, a C-shaped retainer 24 may be formed by manufacturing a tape-shaped front retainer and curving it in a C-shape. By manufacturing the C-shaped cage 24 with a composite material of synthetic resin, the diameter is not easily increased outward in the radial direction, but the diameter is relatively easily reduced inward in the radial direction. can do. In this way, it is not necessary to set the angle ω formed by the inner peripheral surface of the cage 24 and the engagement surface (the left side surface as viewed in FIG. 6) of the triangular protrusion 24b to an acute angle of 90 degrees or less.

When the cage 24 is assembled to the shell outer ring 16, as shown in FIG. 4, after the leaf spring 25 and the engagement roller 23 are assembled in each pocket 24 a of the cage 24, as shown in FIG. A force is applied to the C-shaped cage 24 in the natural state from the outer peripheral side to form a small diameter state in which both ends overlap as shown in FIG. The cage 24 in a small diameter state is inserted into the shell outer ring 16 through an opening formed by the inner peripheral edge of one flange portion 16a of the shell outer ring 16, and then added to the cage 24 from the outer peripheral side. Remove power. Then, the retainer 24 returns to the C-shaped retainer 24 in a natural state as shown in FIG. 5C by its own restoring elasticity. Then, the retainer 24 comes along the inner peripheral engagement surface 18 of the shell outer ring 16, and in this state, the retainer 24 is prevented from being detached in the axial direction by the both flange portions 16 a and 16 a of the shell outer ring 16 and is disposed. It has been described that the leaf spring 25 and the engagement roller 23 are incorporated in each pocket 24a of the retainer 24 in advance when the retainer 24 is assembled to the shell outer ring 16. However, the retainer 24 is attached to the engagement roller 23. After being assembled to the shell outer ring 16, it may be incorporated into the cage 24.

Next, when assembling the pulley unit 10, the ball and cage of one ball bearing 14, the cage 24 of the one-way clutch 13, the leaf spring 25 and the engaging roller 23, and the ball and cage of the other ball bearing 14. Insert in the sleeve 11 in the order of the container, and then insert the pulley 12. A space for work is secured outside in the radial direction during each insertion work, and the assembly work can be easily performed.

Next, operation | movement of the pulley unit 10 provided with the one-way clutch 13 which concerns on Example 1 comprised in this way is demonstrated.

When the rotational angular speed of the crankshaft of the engine is higher than the rotational angular speed of the rotor shaft of the alternator, that is, when the shell outer ring 16 rotates relative to the inner ring 15 in the locking direction, the engaging roller 23 is a cam of the inner ring 15. Based on the force received from the surface 17 and the urging force of the leaf spring 25, the cam surface 17 is bitten in a wedge shape on the shallow side, that is, on the narrow side of the wedge-shaped space 19, and the inner ring 15 and the shell outer ring 16 Are mechanically coupled, and the one-way clutch 13 is engaged. As a result, the pulley 12 and the sleeve 11 cannot be rotated relative to each other (in a locked state), and the rotational driving force of the crankshaft is transmitted to the rotor shaft of the alternator.

On the other hand, when the rotational angular velocity of the rotor shaft of the alternator becomes higher than the rotational angular velocity of the crankshaft of the engine, the engaging roller 23 is on the side where the cam surface 17 is deep, that is, the wedge-shaped space 19 is wide. The engagement roller 23 is released from engagement, the inner ring 15 and the shell outer ring 16 are mechanically disconnected, and the one-way clutch 13 is disengaged. At this time, since the ball bearings 14 and 14 support the radial load on both sides of the one-way clutch 13, the one-way clutch 13 can maintain good meshing performance and durability. Thereby, the relative rotation of the pulley 12 and the sleeve 11 becomes free (overrun state).

According to the first embodiment, a split portion is provided at one location of the retainer 24, is C-shaped, and does not require post-bending of the flange portions 16a and 16a of the shell outer ring 16, so The bending process can be abolished and a significant cost reduction can be realized.

FIG. 7 is a schematic diagram illustrating a main part of the one-way clutch 13 according to the second embodiment of the present invention. In the one-way clutch 13 according to the first embodiment, the split portion of the C-shaped retainer 24 is kept open. However, in the one-way clutch 13 according to the second embodiment, one open end of the C-shaped retainer 24 is left. An inverted trapezoidal hooking portion 24c is provided at the other end, and a trapezoidal hooking portion 24d is provided at the other open end so that the hooking portion 24c and the hooking portion 24d can be fitted together. As a result, when the cage 24 is assembled to the shell outer ring 16, the latching portion 24c and the latched portion 24d are removed to allow the cage 24 to be deformed to a smaller diameter, thereby allowing the shell outer ring 16 of the cage 24 to be deformed. The retainer 24 is assembled to the shell outer ring 16, and the retainer 24c and the latched portion 24d are engaged to form the retainer 24 in an annular shape. The above-described diameter expansion deformation is prevented so that the cage 24 is prevented from contacting the shell outer ring 16.

An inverted trapezoidal hooking portion 24c is provided at one open end of the C-shaped cage 24, and a trapezoidal hooking portion 24d is provided at the other open end. The hooking portion 24c and the hooking portion 24d are provided. However, as for the latching means of the latching portion 24c and the latched portion 24d, if both are coupled and the C-shaped cage 24 does not expand its diameter, Any latching means may be used.

In the one-way clutch 13 according to the second embodiment configured as described above, the latching part 24c and the latching part 24d are latched and the cage 24 is assembled to the shell outer ring 16 → the latching part 24c and the latching part 24c. Although the number of assembling steps is slightly increased in the form of re-engagement of the stopper 24d, there is an effect that the diameter expansion deformation of the cage 24 can be prevented more reliably.

As mentioned above, although each example of the present invention was described, these are only illustrations, the present invention is not limited to these, and the knowledge of those skilled in the art can be used without departing from the spirit of the claims. Various modifications based on this are possible.

For example, in each embodiment, the outer peripheral surface of the inner ring 15 of the one-way clutch 13 is the cam surface 17 and the inner peripheral surface of the outer ring 16 is the inner peripheral engagement surface 18, but the outer peripheral surface of the inner ring 15 is the outer peripheral engagement surface. The inner ring surface of the outer ring 16 may be a cam surface.

Further, in each embodiment, the wedge member of the one-way clutch 13 is the engaging roller 23, but it goes without saying that the present invention can be similarly applied to a one-way clutch in which the wedge member is a ball, a sprag or the like. .

Further, in each embodiment, the urging member is the leaf spring 25, but other urging members such as a coil spring and a disc spring may be used instead of the leaf spring 25.

1 is a side cross-sectional view showing a pulley unit in which a one-way clutch according to Embodiment 1 of the present invention is disposed. 1 is a perspective view of a main part of a one-way clutch according to a first embodiment. FIG. 3 is a plan view of a main part of the one-way clutch according to the first embodiment. 1 is a perspective view of a main part of a one-way clutch according to a first embodiment. (A)-(c) is a figure explaining the assembly | attachment process to the shell outer ring | wheel of a holder | retainer. The figure explaining the rotation prevention means with respect to the inner ring | wheel of a holder | retainer, and a diameter expansion prevention means. The principal part top view of the one-way clutch which concerns on Example 2 of this invention.

Explanation of symbols

10 Pulley unit 11 Sleeve 12 Pulley 13 One-way clutch 14 Ball bearing 15 Inner ring 16 Shell outer ring (outer ring)
17 Cam surface 18 Inner peripheral engagement surface 23 Engagement roller (wedge member)
24 Cage 24a Pocket 24b Triangular protrusion (Regulated part)
24c Hook 24d Hook

Claims (5)

In the one-way clutch formed by urging the wedge member in one direction by the urging member on the cage disposed between the outer ring and the inner ring,
The outer ring is a shell outer ring having flanges on both sides, and the cage is formed so as to be C-shaped in a natural state, and is elastic until its outer diameter is smaller than the inner diameter of the flange of the shell outer ring. The outer diameter of the retainer is applied to the retainer from the outer peripheral side to form a small diameter state in which both ends overlap each other , and the retainer in the small diameter state is placed inside one of the flange portions of the shell outer ring. One way characterized in that the cage is assembled to the shell outer ring by inserting from the opening formed by the peripheral edge and removing the force applied to the cage from the outer peripheral side to expand the diameter. clutch.   A triangular protrusion is formed on the inner peripheral surface of the retainer as a restricted portion that is hooked on the ramp surface that constitutes the cam surface of the inner ring, and an angle formed by the outer peripheral surface of the inner ring and the ramp surface, The one-way clutch according to claim 1, wherein the angle formed by the inner peripheral surface and the engagement surface of the triangular protrusion is set to an acute angle.   The one-way clutch according to claim 1, wherein the wedge member is an engagement roller. The hook portion at one end of said retainer, said the latched portion provided on the other end of the cage, so that the retainer in the state in which the hook portion is hooked to the object engaging portion is not expanded The one-way clutch according to any one of claims 1 to 3. In the method of manufacturing a one-way clutch, wherein a wedge member is urged in one direction by an urging member on a cage disposed between an outer ring and an inner ring.
The outer ring is a shell outer ring having flanges on both sides, and the cage is formed to be C-shaped in a natural state. The small diameter overlapping state is inserted, and the small diameter retainer is inserted from the opening formed by the inner peripheral edge of one flange of the shell outer ring, and the force applied from the outer peripheral side to the retainer is removed. The method of manufacturing a one-way clutch, wherein the cage is assembled to the shell outer ring by expanding the diameter.

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