JP2009299832A - One-way clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain abrasion in an engaging part between an engaging piece, and a clutch outer ring and a clutch inner ring. <P>SOLUTION: A bearing part 13 and a clutch part 14 are juxtaposed in the axial direction between the clutch outer ring 11 and the clutch inner ring 12, and the bearing part 13 is formed with a grease reservoir 29 between a seal 21 and a ball 16 for sealing an outer end part in the axial direction of the bearing part inside. A retainer 17 for holding a sprag 18 of the clutch part 14 and a bearing cage 15 for holding the ball 16 of the bearing part 13 are integrally formed. The seal 21 is formed by integrating a noncontact projection part 28 into the ball 16, and this projection part 28 is arranged while filling up the grease reservoir 29. Grease supplied to a space on the clutch part 14 side between the clutch outer ring 11 and the clutch inner ring 12, is prevented from being pushed out to the grease reservoir 29 by this projection part 28, and the abrasion is restrained in the engaging part between the sprag 18, and the clutch outer ring 11 and the clutch inner ring 12. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a one-way clutch that transmits one-way rotation of a driving member to a driven member and a clutch with a resin pulley in which the one-way clutch is incorporated.

  Generally, in an internal combustion engine of an automobile, rotation of an engine crankshaft is transmitted to a rotation shaft of an engine auxiliary machine such as an alternator via a belt transmission.

  In such an engine accessory drive device, when the engine is suddenly decelerated, the pulley attached to the rotating shaft of the engine accessory also tries to decelerate rapidly. However, when the engine accessory is an alternator, the rotating shaft of the alternator has a large inertia force, so the pulley attached to the rotating shaft tries to keep rotating at a constant speed, and the pulley on the crankshaft and the rotating shaft of the alternator A large rotational speed difference is generated between the upper pulley and the belt tension increases, and the belt is easily damaged.

  Also, the crankshaft has an angular velocity that changes during one rotation, and due to the change in the angular velocity, slippage occurs between the pulley on the crankshaft and the belt, and the belt wears due to the slippage. Decreases.

  In order to solve this problem, a clutch built-in pulley in which a one-way clutch is incorporated in a pulley provided on a rotating shaft of an engine accessory has been proposed (see Patent Document 1).

  For example, as shown in FIG. 6, the one-way clutch 40 incorporated in the pulley with a built-in clutch has a bearing portion 43 and a clutch portion 44 arranged in the axial direction between a clutch outer ring 41 and a clutch inner ring 42. ing.

  In the bearing portion 43, a plurality of rolling elements 46 are held by a bearing cage 45. In the clutch portion 44, the engaging element 51 is held at intervals in the circumferential direction by a retainer 49, and the retainer 49 is formed integrally with the bearing retainer 45.

  In the one-way clutch 40, only when the clutch outer ring 41 or the clutch inner ring 42 is relatively rotated in one direction, the engaging element 51 is engaged with the clutch outer ring 41 and the clutch inner ring 42 to transmit the rotational force.

  When this pulley with a built-in clutch is mounted on the rotating shaft of the engine accessory, if the rotating speed of the pulley falls below the rotating speed of the rotating shaft of the engine accessory, the transmission of the rotational force of the one-way clutch is cut off and the pulley rotates freely. To do. As a result, an increase in belt tension can be prevented, and slippage between the pulley and the belt can be prevented, so that a decrease in durability of the belt can be suppressed.

JP 2001-187931 A

  Meanwhile, between the clutch outer ring 41 and the clutch inner ring 42, one end is closed by a seal 47 provided at the outer end in the axial direction of the bearing portion 43, and the other end is closed by an annular seal plate 52. The seal 47 and the seal plate 52 seal grease filled between the clutch outer ring 41 and the clutch inner ring 42.

  The grease lubricates the engaging portion between the engaging element 51, the clutch outer ring 41 and the clutch inner ring 42, and the inside of the bearing portion 43. However, the transmission of the rotational force of the one-way clutch 40 is cut off and the clutch outer ring 41 is By rotating in the other direction, the engaging element 51 is also rotated, and the grease is stirred during the rotation.

  The stirred grease is pushed out to the space (grease pool 48) between the rolling element 46 and the seal 47 of the bearing portion 43 by the idler engaging member 51, and adheres to the inner surface in the axial direction of the seal 47 of the bearing portion 43. (See symbol G in FIG. 7).

  Since the grease attached to the seal 47 is difficult to return to the engaging element 51, the amount of grease at the engaging portion is insufficient, and it becomes difficult to form an oil film necessary for lubrication. As a result, there is a problem that insufficient lubrication occurs, wear occurs at the engaging portion, the clutch function is lowered, and the life of the clutch is lowered.

  Accordingly, an object of the present invention is to suppress the occurrence of wear at the engaging portion between the engagement element, the clutch outer ring, and the clutch inner ring.

  In order to solve the above-described problem, a one-way clutch according to the present invention includes a bearing portion and a clutch portion arranged in an axial direction between a clutch outer ring and a clutch inner ring, and the bearing portion is provided by a bearing cage. A plurality of rolling elements are held, a grease reservoir is formed between the rolling element and a seal that seals the axially outer end portion inside the bearing portion, and the clutch portion has an engaging element in a circumferential direction by a cage. Only when the retainer is formed integrally with the bearing retainer and one of the clutch outer ring or the clutch inner ring rotates relative to the other in one direction. In a one-way clutch that engages with an outer ring of a clutch and an inner ring of a clutch and transmits a rotational force, the seal has a protruding portion that is non-contact with the rolling element on an inner surface in the axial direction, and the protruding portion is It was a structure provided in a state to fill the reservoir.

  If it does in this way, since the grease pool of a bearing part is filled with the protrusion part provided in the seal | sticker of the bearing part, grease will not be extruded to a grease pool by the idler of an idler. For this reason, the amount of grease pushed out into the grease reservoir is reduced, the amount of grease at the engaging portion of the engagement element, the clutch outer ring and the clutch inner ring is secured, and an oil film necessary for lubrication at the engaging portion is formed, Wear can be suppressed.

  Also, in order to fill the grease reservoir, for example, a structure in which a seal is provided on the inner side in the axial direction of the conventional bearing part, or a rolling element is rolled on the outer side in the axial direction than the conventional bearing part. The conventional bearing portion excluding the seal can be used as it is by adopting the seal having the above-described configuration.

  In this configuration, it is possible to adopt a configuration in which the protruding portion is formed integrally with the seal, and the seal is formed of a thermoplastic elastomer. If it does in this way, it will become possible to manufacture the seal | sticker which consists of a thermoplastic elastomer which has a protrusion part by integral molding, and a seal | sticker can be manufactured cheaply.

  There are various types of thermoplastic elastomers that form the seal, such as styrene, olefin, ester, and amide. For example, a thermoplastic polyester elastomer can be used. Thermoplastic polyester elastomer has a good balance between mechanical strength and flexibility, and is superior in ozone resistance compared to NBR (acrylonitrile butadiene rubber) generally used as a seal. This is because the durability of the seal can be improved.

  Moreover, when employ | adopting the structure which provides a protrusion part in a seal | sticker, it is good also as a structure by which the spacer was provided in the axial direction inner surface of the said seal | sticker, and this spacer was made into the said protrusion part. If it does in this way, the seal | sticker which has a protrusion part can be manufactured by providing the spacer in the seal | sticker using the seal | sticker conventionally used.

  When adopting a configuration in which a spacer is provided on the inner surface in the axial direction of the seal, the seal can be formed by an elastic body reinforced with a core metal, and the spacer can be provided on the inner surface in the axial direction of the core metal. In this case, since the spacer is provided on the metal core that reinforces the elastic body, the spacer can be securely fixed to the seal.

  The spacer may be made of a material having durability against grease filled between the clutch outer ring and the clutch inner ring, and may be formed of, for example, a thermoplastic elastomer or a steel material.

  Further, when the bearing portions are provided on both sides of the clutch portion, the radially inward load received by the clutch outer ring can be received by both the bearing portions, compared with a case where a single bearing portion is provided. Thus, a larger load can be received.

  In the clutch with a resin pulley according to the present invention, a configuration in which a resin pulley is provided on the outer periphery of the clutch outer ring of the one-way clutch having the above-described configuration can be employed.

  In the one-way clutch according to the present invention, since the grease reservoir of the bearing portion is filled by the protrusion provided on the seal of the bearing portion, the grease pushed out to the bearing space is reduced when the outer ring of the clutch is rotated, and the engagement of the engagement element is reduced. An oil film necessary for lubrication at the joint is formed, and wear at the engaging portion is suppressed.

  Moreover, since the grease reservoir of the bearing portion is filled with the seal, the conventional bearing portion excluding the seal can be used as it is.

  1 to 3 show a first embodiment of the present invention. As shown in FIG. 1, the clutch with pulley is applied to an auxiliary drive device for an automobile, and includes a one-way clutch 10 and a pulley 20 provided on the outer periphery thereof. A double row V-groove is provided.

  The one-way clutch 10 is configured such that a bearing portion 13 and a clutch portion 14 are arranged in the axial direction between a clutch outer ring 11 having a pulley 20 integrated on the outer periphery and a clutch inner ring 12.

  A plurality of balls 16 as rolling elements are held by a bearing cage 15 between the outer ring 23 and the inner ring 24, and the bearing portion 13 is provided at one end in the axial direction between the clutch outer ring 11 and the clutch inner ring 12.

  As shown in FIG. 2, the clutch portion 14 is held by a cage 17 so that a plurality of sprags 18 as engaging members can be tilted at intervals in the circumferential direction. The retainer 17 is formed with a pocket 30 for individually accommodating each sprag 18 and a space for accommodating the elastic member 33. The accommodated elastic member 33 urges the sprag 18 in a direction in which the cam surface formed on each sprag 18 engages the clutch outer ring 11 and the clutch inner ring 12.

  Further, the cage 17 and the bearing cage 15 are integrally formed of synthetic resin to form an integrated cage 19 (see FIG. 1).

  Between the clutch outer ring 11 and the clutch inner ring 12, one end in the axial direction is closed by a seal 21 provided at the outer end in the axial direction of the bearing portion 13, and the other end is closed by an annular seal plate 22. ing. The seal 21 and the seal plate 22 seal the grease filled between the clutch outer ring 11 and the clutch inner ring 12.

  As shown in FIG. 3, the bearing portion 13 has seal engagement grooves 25 and 25 formed at both ends of the inner diameter surface of the outer ring 23, and the outer diameter surface of the inner ring 24 facing the seal engagement groove 25. Seal grooves 26 are formed at both ends.

  The outer peripheral portion of the seal 21 is engaged with the seal engagement groove 25 on the outer side in the axial direction of the outer ring 23, and a lip 27 formed on the inner peripheral portion of the seal 21 is in sliding contact with the seal groove 26. The lip 27 may form a labyrinth seal with respect to the seal groove 26.

  The seal 21 of the bearing portion 13 is made of a thermoplastic elastomer, and has an axially inward protruding portion 28 that is not in contact with the ball 16 on the inner surface in the axial direction. The protruding portion 28 is integrated with the seal 21. Is formed.

  The thermoplastic elastomer as the material of the seal 21 can impart flexibility while maintaining mechanical strength as a seal, and various types such as styrene, olefin, ester and amide are known. . Among them, thermoplastic polyester elastomers have a good balance between mechanical strength and flexibility, and heat resistance and ozone resistance compared to NBR (acrylonitrile butadiene rubber) as an elastic body generally used for sealing. Since it is excellent in the property, the durability can be improved by forming as a sealing member.

  The protruding portion 28 is formed so as to fill a space 29 (grease pool 29) formed between the seal 21 and the ball 16 between the outer ring 23 and the inner ring 24 (inside the bearing portion 13). The radial cross-sectional shape of the protruding portion 28 can be appropriately determined according to the radial cross-sectional shape of the grease reservoir 29 as long as the rolling of the ball 16 is not hindered.

  In the clutch with pulley according to the first embodiment, when the clutch outer ring 11 rotates in the direction of arrow a in FIG. 2, the sprag 18 is engaged and locked between the clutch outer ring 11 and the clutch inner ring 12, and the rotational force is not shown. Transmitted to the shaft. Further, when the clutch outer ring 11 rotates in the direction opposite to the arrow a in FIG. 2, the engagement of the sprag 18 with the clutch outer ring 11 and the clutch inner ring 12 is released, and the sprag 18 idles.

  As shown in FIG. 3, the seal 21 of the bearing portion 13 fills the grease reservoir 29 of the bearing portion 13 with the protruding portion 28. Therefore, the grease supplied to the space on the clutch portion 14 side between the clutch outer ring 11 and the clutch inner ring 12 is not pushed out to the grease reservoir 29 due to idling of the clutch.

  As a result, an amount of grease necessary for lubrication at the engagement portion between the sprag 18, the clutch outer ring 11 and the clutch inner ring 12 is ensured, and an oil film necessary for lubrication at the engagement portion is formed. By forming the oil film, wear of the sprag 18 and the clutch outer ring 11 or the clutch inner ring 12 can be suppressed, and a decrease in the clutch function is prevented.

  The structure of the seal 21 of the bearing portion 13 can be appropriately changed as long as the grease reservoir 29 of the bearing portion 13 can be filled. As an example, a second embodiment of the present invention is shown in FIG. In the following description, differences from the first embodiment will be mainly described, and the same reference numerals will be used for the same possible configurations.

  As shown in FIG. 4, the seal 21 of the bearing portion 13 is obtained by reinforcing an elastic body such as a synthetic rubber with a core metal 31 made of a plate-shaped annular body, and the core metal 31 on the inner surface in the axial direction thereof. Is exposed. A spacer 32 is fixed to the exposed part of the cored bar 31.

  The spacer 32 is an annular body made of a thermoplastic elastomer and protrudes inward in the axial direction with respect to the seal 21.

  The material of the spacer 32 is not limited to a thermoplastic elastomer, and may be a steel material. If it is made of steel, it can be fixed to the core 31 of the seal 21 by welding, and the spacer 32 can be fixed to the seal 21 more firmly.

  When a thermoplastic elastomer is used as a material for the spacer 32, various types such as styrene, olefin, ester and amide are known. Among them, mechanical strength is obtained when a thermoplastic polyester elastomer is used. And a good balance of flexibility.

  Since this spacer 32 fills the grease reservoir 29 of the bearing portion 13, as in the case of the first embodiment described above, the clutch idling is supplied to the space on the clutch portion 14 side between the clutch outer ring 11 and the clutch inner ring 12. The grease is not pushed out into the grease reservoir 29.

  As a result, also in the second embodiment, the amount of grease necessary for lubrication at the engaging portion of the sprag 18, the clutch outer ring 11 and the clutch inner ring 12 is ensured, and an oil film necessary for lubrication at the engaging portion is formed.

  Next, a third embodiment of the present invention is shown in FIG. The clutch with a pulley according to this embodiment includes a clutch portion 14 and bearing portions 13 (13a, 13b) arranged in the axial direction between the clutch outer ring 11 and the clutch inner ring 12 in the one-way clutch 10. This is different from the case of the first embodiment described above. Other configurations are the same as those of the first embodiment, and the same reference numerals are used for the same configurations, and the description thereof is omitted.

  In this embodiment, the bearing portions 13a and 13b are provided at both ends in the axial direction between the clutch outer ring 11 and the clutch inner ring 12, respectively. The bearing cage 15a of the one bearing portion 13a (one axial end side) and the cage 17 of the clutch portion 14 are integrally formed of a synthetic resin to form an integrated cage 19. The bearing cage 15b of the other bearing portion 13b (the other axial end side) is independent of the cage 17 of the clutch portion 14.

  Between the clutch outer ring 11 and the clutch inner ring 12, one end portion in the axial direction is closed by a seal 21a provided at the outer end portion in the axial direction of the bearing portion 13a, and the other end portion is closed by a seal 21b of the bearing portion 13b. ing. The seals 21 a and 21 b seal the grease filled between the clutch outer ring 11 and the clutch inner ring 12.

  In this embodiment, as in the case of the first embodiment, due to idling of the clutch, the grease is not pushed outward in the axial direction from the rolling elements 16a, 16b of the bearing portions 13a, 13b, and the sprag 18, the clutch outer ring 11, and the clutch inner ring The amount of grease necessary for lubrication at the 12 engaging portions is ensured, and an oil film necessary for lubrication at the engaging portions is formed.

  Further, in this embodiment, the seals 21a and 21b of both the bearing portions 13a and 13b reinforce the elastic body with a cored bar 31 made of a plate-shaped ring as shown in the second embodiment of FIG. The spacer 32 can be fixed to the exposed portion of the core 31 exposed on the inner surface in the axial direction.

Sectional drawing which shows the one-way clutch of 1st Embodiment. Sectional view along the II-II line of FIG. Sectional drawing which shows the bearing part of the one-way clutch of 1st Embodiment. Sectional drawing which shows the bearing part of the one-way clutch of 2nd Embodiment. Sectional drawing which shows the one way clutch of 3rd Embodiment Sectional view showing a conventional one-way clutch Sectional drawing which shows the bearing part of the one-way clutch same as the above

Explanation of symbols

10, 40 One-way clutch 11, 41 Clutch outer ring 12, 42 Clutch inner ring 13, 13a, 13b, 43 Bearing portion 14, 44 Clutch portion 15, 45 Bearing portion retainer 16, 46 Rolling element (ball)
17, 49 Cage 18, 51 Engaging element (sprag)
19 Integrated cage 20 Pulley 21, 21a, 21b, 47 Seal 22, 52 Seal plate 23 Outer ring 24 Inner ring 25 Seal engagement groove 26 Seal groove 27 Lip 28 Protruding part 29, 48 Grease reservoir 30 Pocket 31 Core metal 32 Spacer 33 Elasticity Element

Claims (9)

Between the outer ring of the clutch and the inner ring of the clutch, a bearing portion and a clutch portion are provided side by side in the axial direction, and the bearing portion holds a plurality of rolling elements by a bearing cage, A grease reservoir is formed between the seal that seals the end portion and the rolling element, and the clutch portion is held by the retainer at intervals in the circumferential direction by the retainer, and the retainer is the bearing retainer Only when one of the clutch outer ring or the clutch inner ring rotates relative to the other in one direction, the engaging element engages with the clutch outer ring and the clutch inner ring and transmits the rotational force. In the direction clutch,
The one-way clutch according to claim 1, wherein the seal has a protruding portion that is in non-contact with the rolling element on an inner surface in the axial direction, and the protruding portion is provided so as to fill the grease reservoir.   2. The one-way clutch according to claim 1, wherein the protrusion is formed integrally with the seal, and the seal is formed of a thermoplastic elastomer.   The one-way clutch according to claim 2, wherein the thermoplastic elastomer is a thermoplastic polyester elastomer.   The one-way clutch according to claim 1, wherein a spacer is provided on an inner surface in the axial direction of the seal, and the spacer serves as the protruding portion.   The one-way clutch according to claim 4, wherein the seal is formed of an elastic body reinforced with a cored bar, and the spacer is provided on an inner surface in the axial direction of the cored bar.   The one-way clutch according to claim 4, wherein the spacer is made of a thermoplastic elastomer.   6. The one-way clutch according to claim 4, wherein the spacer is made of a steel material.   8. The bearing according to claim 1, wherein the bearing portions are respectively provided on both sides of the clutch portion, and the bearing cage of the one bearing portion is formed integrally with the cage. Direction clutch.   A clutch with a resin pulley in which a resin pulley is provided on an outer periphery of a clutch outer ring of the one-way clutch, wherein the one-way clutch is a one-way clutch according to any one of claims 1 to 8. .

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