JP2008256044A - One-way clutch and pulley device with built-in one-way clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive one-way clutch and pulley device with built-in one-way clutch, suppressing heat generation or wear caused by friction between a spring and an engaging element. <P>SOLUTION: The spring 19 of the one-way clutch is formed of a plate spring. Both sides of a base 25 as a longitudinal intermediate part are bent at predetermined positions as bent portions 26 to form pushing and pressing parts 27, and the end parts 28 of the pushing and pressing parts 27 are bought into contact with rollers. Thereby, the spring 19 push-presses the rollers toward a locking direction by the end parts 28. For suppressing heat generation or wear caused by friction between the spring 19 and the roller 17, the portions with a longitudinal end surface and front and rear planes continued, of the end parts 28 of the spring 19 are formed into convex curved surfaces 28a, and the convex surfaces are shaped into a smooth surface by press working. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a one-way clutch and a pulley device with a built-in one-way clutch. More specifically, the present invention relates to an input shaft of an auxiliary machine such as an alternator driven by the power of an engine crankshaft, or power to an engine crankshaft. The present invention relates to an improvement in a one-way clutch of a pulley device with a built-in one-way clutch that is used by being fixed to an output shaft of a starter motor.

  2. Description of the Related Art Conventionally, various auxiliary machines are driven using a drive engine of an automobile as a drive source. For example, when driving an alternator that generates electric power necessary for an automobile, a clutch built-in type pulley apparatus incorporating a one-way clutch is used. It is known to use (see, for example, Patent Document 1).

  For example, a one-way clutch has a cam surface on an inner ring or an outer ring so that a wedge space is formed between an inner ring and an outer ring, and a locked state and an overrun state are achieved by engaging and disengaging rollers disposed in the wedge space. And repeat. Each roller arranged in the wedge space is accommodated in a plurality of pockets formed in the cage, and is elastically pressed in the direction of exerting the wedge action, that is, the lock direction, by a spring locked to the cage. Is done.

As shown in FIG. 10, the spring 100 used for the one-way clutch includes a base portion 101, a pair of pressing portions 102 bent with respect to the base portion 101 on both sides of the base portion 101, and a pressing portion on the distal end side of the pressing portion 102. The leaf spring has a pair of contact portions 103 that are bent with respect to 102 and contact the roller. As a result, contact between the tip 104 having burrs and the roller is avoided, and heat generation and wear due to friction between the spring 100 and the roller are suppressed.
JP-A-8-61433

  Incidentally, in the spring 100 shown in FIG. 10, the material is wasted only from the contact portion 103 to the tip portion 104, which does not affect the spring characteristics, and the material cost increases. In addition, a process of bending the pressing portion 102 is required, and the bending process also requires accuracy of the bending angle, which increases the cost.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to reduce heat generation and wear due to friction between the spring and the engagement element, and to reduce the cost of the one-way clutch and the one-way clutch built-in pulley device. Is to provide.

The above object of the present invention can be achieved by the following constitution.
(1) An inner member, an outer member disposed concentrically with the inner member outside the inner member, and the inner member disposed between the inner member and the outer member. Only when one of the outer members tends to rotate relative to the other in a predetermined direction, a plurality of engagement elements that engage with the peripheral surfaces of both the inner member and the outer member; A one-way clutch comprising: a cage that holds the plurality of engagement elements; and a spring that is attached to the cage and biases the plurality of engagement elements.
The one-way clutch, wherein a tip portion of the spring that contacts the plurality of engaging members has a smooth surface shape by press working.
(2) The tip of the spring has a concave curved surface having a larger radius of curvature than the engagement element so as to reduce a contact surface pressure when the engagement element contacts. One way clutch.
(3) A one-way clutch built-in pulley apparatus comprising the one-way clutch according to (1) or (2).

  According to the one-way clutch and the pulley device with a built-in one-way clutch of the present invention, the tip portion of the spring that contacts the plurality of engagement elements has a smooth surface shape by pressing, so that the friction between the spring and the engagement element While suppressing heat generation and wear, the cost is low.

  Hereinafter, a one-way clutch and a pulley device with a built-in one-way clutch according to each embodiment of the present invention will be described in detail with reference to the drawings.

(First embodiment)
First, with reference to FIGS. 1-6, 1st Embodiment of this invention is described in detail. As shown in FIG. 1, the pulley apparatus 10 with a built-in clutch includes a sleeve 11 into which a rotating shaft (not shown) of an auxiliary machine such as an alternator is screwed, and a sleeve 11 radially outside the sleeve 11. And a pulley 12 having a belt groove 12a formed on the outer peripheral surface thereof. A drive belt (not shown) suspended from a drive pulley (not shown) fixed to the crankshaft of the engine is stretched over the belt groove 12a.

  In addition, 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 rolling bearings 14 is disposed between the outer peripheral surface at both axial ends of the sleeve 11 and the inner peripheral surface at both axial ends of the pulley 12, which are spaced apart. The one-way clutch 13 transmits a rotational force between the pulley 12 and the sleeve 11 only when the pulley 12 tends to rotate relative to the sleeve 11 in a predetermined direction. As the rolling bearing 14, a deep groove ball bearing or the like is used, and the sleeve 11 and the pulley 12 can be rotated relative to each other while supporting a radial load applied to the pulley 12.

  The one-way clutch 13 is an inner ring 15 that is an inner member that is press-fitted and fixed to the outer peripheral surface of the sleeve 11, and an outer ring that is press-fitted and fixed to the inner peripheral surface of the pulley 12 and is arranged concentrically with the inner ring 15 on the outer side of the inner ring 15. An outer ring 16 that is a side member, and a plurality of rollers 17 that are engaging elements disposed between the outer peripheral surface of the inner ring 15 and the inner peripheral surface of the outer ring 16. The outer peripheral surface of the inner ring 15 forms a cam surface in which a plurality of ramp portions 15a are formed at predetermined intervals in the circumferential direction, and the roller 17 is formed from the cylindrical surface 16a of the outer ring 16 and each ramp portion 15a. It is rotatably held in the wedge space.

  The one-way clutch 13 includes a cage 18 having a plurality of pockets for individually accommodating the rollers 17 and a spring 19 (see FIG. 2) that elastically presses the rollers 17 in a direction in which the wedge space is engaged. ) And.

  As shown in FIG. 2, the retainer 18 includes a pair of annular portions 20 and a plurality of column portions 21 that connect the pair of annular portions 20.

  Protrusions (not shown) that engage with both axial ends of the lamp portion 15 a are formed on the inner peripheral surfaces of the pair of annular portions 20, and the cage 18 rotates together with the inner ring 15 and the sleeve 11. In addition, a pair of end-side spring holding portions 22 are radially outward from the outer peripheral surface side of each column portion 21 at a portion that is aligned with each column portion 21 in the circumferential direction on the inner side surface of the pair of annular portions 20. It is formed in a state protruding to On the other hand, the center side spring holding part 23 is formed in the axial direction center part of each pillar part 21 in the state which protrudes radially outward from the outer peripheral surface side of each pillar part 21. As shown in FIG. The spring 19 is sandwiched between one circumferential side surface of the end side spring holding portion 22 and the other circumferential side surface of the center side spring holding portion 23.

  As shown in FIGS. 2 and 3, the spring 19 is formed of a leaf spring, and forms a pressing portion 27 by bending both sides of a base portion 25 that is an intermediate portion in the longitudinal direction as a bending portion 26 at a predetermined position. The tip portion 28 of the pressing portion 27 is in contact with the roller 17. As a result, the spring 19 comes into contact with each roller 17 at the tip 28 and presses each roller 17 in the locking direction, that is, toward the shallow side of the groove of the ramp portion 15a.

  The pulley apparatus 10 with a built-in one-way clutch configured in this way has a tendency that the outer ring 16 rotates relative to the inner ring 15 in a predetermined direction when the rotational angular speed of the pulley 12 is faster than the rotational angular speed of the rotating shaft. In this case, the roller 17 is engaged with the wedge space between the cylindrical surface of the outer ring 16 and the ramp portion 15a of the inner ring 15 by the wedge action, and the rollers 17 are interposed between the outer ring 16 and the inner ring 15 via the respective rollers 17. Rotational force can be transmitted freely. As a result, the pulley 12 and the sleeve 11 cannot be rotated relative to each other (in a locked state), and the rotational force of the engine is transmitted to the rotating shaft. On the other hand, when the rotational angular velocity of the pulley 12 is slower than the rotational angular velocity of the rotating shaft, the engagement of the roller 17 is released, and the pulley 12 and the sleeve 11 can be freely rotated (overrun state).

  Here, the pressing portion 27 of the spring 19 includes a straight portion 27a from the bent portion 26 to the intermediate portion, a tapered portion 27b that gradually decreases in width from the straight portion 27a toward the distal end portion 28, and a tapered portion 27b. A straight portion 27c from the tip to the tip 28 is formed. Thereby, even when the spring 19 is bent in a state where the spring 19 is disposed in the cage 18, the tip portion 28 is separated from the surface of the column portion 21, and interference between the vicinity of the tip portion 28 and the cage 18 is prevented. Further, by providing the straight portion 27c without forming the tapered portion 27b up to the distal end portion 28, the width t (see FIG. 5B) of the distal end portion 28 is prevented from becoming too small. Further, the tip portion 28 of the spring 19 is formed to have a smooth surface shape by forming a convex curved surface 28a at a portion where the longitudinal end surface and the front and back planes are continuous in order to suppress heat generation and wear due to friction between the spring 19 and the roller 17. is doing. As shown in FIG. 4A, the pressing portion 27 of the spring 19 may be a stepped portion 27b ′ between the straight portions 27a and 27c. In this embodiment, however, the pressing portion 27 is punched by a press described later. The taper portion 27b is taken into consideration. Further, the spring pressing portion 27 is not provided with a straight portion at the distal end portion 28, but is tapered from the middle of the pressing portion 27 to the distal end portion 28 (see FIG. 4B) or a gentle curved shape. Is also possible. Thereby, even when a spring width is comparatively large, the width | variety of the front-end | tip part 28 can be changed.

  As shown in FIG. 5A, the spring 19 is first cut from a long plate material B in a shape following the spring 19 before being bent by a press. Since the burrs remain on the cut end surface of the spring 19, as shown in FIG. 5 (b), the distal end portion 28 after cutting is pressed by pressing to form a smooth convex curved surface 28a, and the burrs at the distal end portion 28 are removed. To do. Thereby, the front-end | tip part 28 is finished in the smooth surface shape where the surface which contacts the holder | retainer 18 is round. In addition to the press work, the tip portion 28 may be further polished and finished to a smooth surface shape. Thereafter, the spring 19 is formed by bending at a position where the bent portion 26 is to be formed.

  Therefore, according to the one-way clutch 13 and the pulley device 10 with a built-in one-way clutch according to the present embodiment, the tip portion 28 of the spring 19 that comes into contact with the plurality of rollers 17 has a smooth surface shape by pressing. Heat generation and wear due to friction between the roller 19 and the roller 17 can be suppressed. Further, since the tip portion 28 comes into contact with the roller 17, the material of the spring 19 is reduced, the labor of the processing process can be saved, and the cost becomes low.

  The tip portion 28 of the spring 19 only needs to have a smooth surface shape. Like the spring 19a shown in FIG. 6A, the tip portion 28 is a central portion of the axial end surface between the convex curved surfaces 28a. Further, as shown in FIG. 6 (b), the distal end portion 28 is smooth as a convex curved surface 28c where the axial end surface and the width-direction tapered surface are continuous. The surface shape may be finished.

(Second Embodiment)
Next, a second embodiment of the present invention will be described in detail with reference to FIGS. The present embodiment is different from the first embodiment only in the shape of the spring of the one-way clutch, and other parts are the same as those in the first embodiment, and the description is omitted or simplified.

  The spring 30 of the present embodiment is also a leaf spring, and constitutes a pressing portion 27 by bending both sides of the base portion 25 at predetermined positions as bent portions (portions where maximum stress is generated) 26, and has a tapered shape. The tip portion 31 of the pressing portion 27 formed in the contact with the roller 17.

Here, as shown in FIGS. 7B and 7C, the end surface 31 in the axial direction of the tip portion 31 is a concave curved surface 31 a having a larger radius of curvature than the transfer surface of the roller 17, and has a smooth surface shape. . Thereby, the front-end | tip part 31 can make small the contact surface pressure at the time of the roller 17 contacting, and the slip between the spring 30 and the roller 17 becomes favorable, and can suppress the heat_generation | fever and abrasion by friction.
Other configurations and operations are the same as those in the first embodiment.

  In addition, the shape of the front-end | tip part 31 of the spring 30 should just have the concave surface 31a, and the flat surface 31b on both sides of the width direction of the axial direction end surface of the front-end | tip part 31 like the spring 30a shown to Fig.8 (a). Alternatively, it may be a concave curved surface 31a ′ that is inclined so that the arc on the side in contact with the roller 17 becomes long like a spring 30b shown in FIG. Moreover, these front-end | tip parts 31 may be formed in combination with the surface shape of the front-end | tip part of 1st Embodiment, and like the spring 30c shown in FIG.8 (c), the concave curved surface 31a of FIG.7 (b). The both sides in the thickness direction may be convex curved surfaces 28a, and the both sides in the thickness direction of the concave curved surface 31a and the plane 31b in FIG. 8 (a) may be convex curved surfaces 28a as in the spring 30d shown in FIG. Further, like the spring 30e shown in FIG. 8 (e), the concave curved surface 31a 'and the flat surface 31b of FIG. 8 (b) are formed with convex curved surfaces 28a on both sides in the thickness direction and convex curved surfaces 28c on both sides in the width direction. May be.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.

In the present embodiment, the inner peripheral surface of the outer ring is a cylindrical surface and the outer peripheral surface of the inner ring is a cam surface, but the inner peripheral surface of the outer ring may be a cam surface and the outer peripheral surface of the inner ring may be a cylindrical surface.
In this embodiment, the inner ring of the one-way clutch is press-fitted into the sleeve and the outer ring of the one-way clutch is press-fitted into the pulley. However, the inner ring may be formed integrally with the sleeve, or the outer ring may be formed integrally with the pulley.
In this embodiment, the pulley device with a built-in clutch is mounted between the rotating shaft of the alternator and the driven pulley. However, it may be mounted between the pulley of the starter and the rotating shaft. Only when there is a tendency to relatively rotate in a predetermined direction, the transmission of the rotational force between the sleeve and the pulley becomes free.

  Further, the leaf spring holding method by the cage of the present invention may be held by the end side spring holding part and the center side spring holding part of the column part as in the present embodiment, or may be attached to a pair of ring parts. A spring holding portion may be provided and held.

  Furthermore, the shape of the tip of the spring of the present invention can also be applied to the spring 40 of the one-way clutch 10a shown in FIG. That is, the spring 40 is formed by bending after pressing, so that the base 41, the front piece 42 formed in the middle in the longitudinal direction of the base 41, the rear piece 43 formed in both longitudinal ends of the base 41, And a pressing portion 44 that curves and extends to both sides from the front end of the front piece 42. The spring 40 is sandwiched between the cage 18 a so as to surround the cage 18 a by the base 41, the front piece 42, and the rear piece 43, and the tip 45 of the pressing portion 44 contacts the roller 17. By configuring the tip 45 of the spring 40 thus formed as in the present invention, the same effect can be achieved.

It is a longitudinal cross-sectional view of the one-way clutch built-in type pulley apparatus which is 1st Embodiment of this invention. It is a top view which shows the holder | retainer and spring of the one-way clutch of FIG. 1 in the state which removed the outer ring | wheel. The spring of the one way clutch of FIG. 1 is shown, (a) is the perspective view, (b) is the principal part perspective view of the front-end | tip part. It is a perspective view which shows the modification of the spring of the one-way clutch of FIG. It is a figure which shows the manufacturing process of the spring of the one-way clutch of FIG. It is a principal part perspective view which shows the front-end | tip part of the spring which concerns on the modification of the one-way clutch of 1st Embodiment. The spring of the one-way clutch which is 2nd Embodiment of this invention is shown, (a) is the perspective view, (b) is the principal part perspective view of the front-end | tip part, (c) is a contact state with a roller. FIG. It is a principal part perspective view which shows the modification of the front-end | tip part of the spring of a one-way clutch. (A) is a one-way clutch which concerns on another form, (b) is a perspective view of the spring of (a). It is a perspective view of the spring of the conventional one-way clutch.

Explanation of symbols

10 Pulley device with built-in clutch 11 Sleeve 12 Pulley 13 One-way clutch 14 Support bearing 15 Inner ring (inner member)
15a Lamp part 16 Outer ring (outer member)
17 Roller 18 Cage 19, 30, 40 Spring 27, 44 Pressing portion 28, 31, 45 Tip portion 28a, 28c Convex surface 31a, 31a 'Concave surface

Claims (3)

An inner member, an outer member disposed concentrically with the inner member outside the inner member, and disposed between the inner member and the outer member, the inner member and the outer member Only when one of the side members tends to rotate relative to the other in a predetermined direction, a plurality of engagement elements that engage with the peripheral surfaces of both the inner member and the outer member; A one-way clutch comprising: a retainer that holds an engagement element; and a spring that is attached to the retainer and biases the plurality of engagement elements.
The one-way clutch, wherein a tip portion of the spring that contacts the plurality of engaging members has a smooth surface shape by press working.   2. The one-way clutch according to claim 1, wherein the tip of the spring has a concave curved surface having a larger radius of curvature than the engagement element so as to reduce a contact surface pressure when the engagement element contacts. .   A one-way clutch built-in pulley apparatus comprising the one-way clutch according to claim 1.

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