JP2008045587A - One-way clutch ad pulley with built-in clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the idling torque of a one-way clutch while suppressing a reduction in the life of the clutch due to wear. <P>SOLUTION: In pockets 14 of a cage 13 incorporated between a clutch outer ring 11 and a clutch inner ring 12, there are incorporated sprags 15 and elastic members 16 for energizing the sprags 15 in the direction of engaging with the inner periphery of the clutch outer ring 11 and the outer periphery of the clutch inner ring 12. Recessed portions 18a, 8b are formed in the outer diameter faces and the inner diameter faces of columnar portions 17 formed between the pockets 14 of the cage 13. Solid lubricants 19 are stored in the recessed portions 18a, 18b for lubricating the sprags 15 and contact portions between the clutch outer ring 11 and the clutch inner ring 12. <P>COPYRIGHT: (C)2008,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 built-in 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 the engine accessory drive apparatus as described above, 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 inertial 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, resulting in durability. Will drop.

  In order to eliminate such an inconvenience, Patent Document 1 proposes 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.

  By installing the clutch built-in pulley as described above on the rotating shaft of the engine accessory, if the pulley rotating speed falls below the rotating speed of the engine accessory rotating shaft, the one-way clutch is disconnected and the pulley rotates freely. Further, it is possible to prevent an increase in belt tension, to prevent slippage between the pulley and the belt, and to suppress a decrease in durability of the belt.

Japanese Patent Laid-Open No. 2005-282851

  By the way, in the one-way clutch as described above, the contact portion between the engagement element, the clutch outer ring and the clutch inner ring is usually lubricated by the grease enclosed inside, but the one-way clutch is disconnected and the clutch outer ring is At the time of free rotation, the engaging member also rotates, and the grease is agitated and sheared at the time of rotation, and the shear resistance becomes rotational resistance, so that there is a disadvantage that idling torque is large.

  In addition, the stirred grease is pushed out and collected in the space on both sides by the idler engaging member, and it becomes difficult to form an oil film necessary for lubrication at the contact portion between the engaging member, the clutch outer ring and the clutch inner ring. There is also an inconvenience that wear occurs at the contact portion and the clutch life is reduced.

  An object of the present invention is to reduce the idling torque of a one-way clutch and to suppress a reduction in clutch life due to wear.

  In order to solve the above problem, in the one-way clutch according to the present invention, the clutch outer ring, the clutch inner ring incorporated inside the clutch outer ring, and the clutch inner ring and the clutch outer ring are incorporated. A retainer, an engagement element accommodated in each of a plurality of pockets formed at intervals in the circumferential direction of the retainer, and an engagement element in a direction to engage with the inner periphery of the clutch outer ring and the outer periphery of the clutch inner ring And an engagement member is engaged with the inner periphery of the clutch outer ring and the outer periphery of the clutch inner ring by relative rotation of the clutch outer ring and the clutch inner ring in one direction. Rotating torque is transmitted between each other, and the contact portion between the engagement element, the clutch outer ring and the clutch inner ring is lubricated by the lubricant filled between the clutch outer ring and the clutch inner ring. In the one-way clutch, the lubricant comprises a solid lubricant obtained by mixing ultra-high molecular polyethylene with lubricating grease or lubricating oil, and the solid lubricant is accommodated in a space that does not hinder the behavior of the engagement element. The configuration was adopted.

  Here, a recess is formed in each of the inner diameter surface and the outer diameter surface of the pillar portion formed between the pockets of the cage, and the solid lubricant is accommodated in the recess, whereby the engagement element, the clutch outer ring, and the clutch inner ring. An oil film necessary for lubrication can be easily formed at the contact portion, wear at the contact portion can be suppressed, and a decrease in clutch life can be suppressed.

  In the pulley with a built-in clutch according to the present invention, a configuration in which the clutch outer ring of the one-way clutch having the above-described configuration is press-fitted into the inner diameter surface of the pulley and the one-way clutch is incorporated in the pulley is adopted.

  As described above, a solid lubricant is employed as the lubricant, and the solid lubricant is accommodated in a space that does not hinder the behavior of the engagement element, so that the one-way clutch in which the engagement element is disengaged is idled. The solid lubricant is not sheared, and the idling torque can be reduced.

  In addition, the base oil infiltrating the surface of the solid lubricant can lubricate the contact portions of the engagement element, the outer ring of the clutch, and the inner ring of the clutch. can do.

  Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1 and FIG. 2, the pulley with a built-in clutch includes a pulley 1, a one-way clutch 10 incorporated inside the pulley 1, and a pair of rolling bearings 20 incorporated on both sides of the one-way clutch 10, A double row V-groove 2 is provided on the outer periphery of the pulley 1 so as to span a V-ribbed belt.

  The one-way clutch 10 incorporates a cage 13 between a clutch outer ring 11 press-fitted into the inner diameter surface of the pulley 1 and a clutch inner ring 12 incorporated therein, and a plurality of one-way clutches 10 formed in the circumferential direction of the cage 13. Each of the pockets 14 has a sprag 15 as an engaging member, and the sprag 15 is urged in an upstanding direction so that the cam surfaces 15a and 15b at both ends are connected to the cylindrical inner surface 11a of the clutch outer ring 11 and the cylindrical shape of the clutch inner ring 12. The sprag type one-way clutch incorporates an elastic member 16 to be brought into contact with the outer surface 12a.

  Here, the axial length of the clutch inner ring 12 is longer than the axial length of the clutch outer ring 11, and between the cylindrical outer surface of both ends located outside the clutch outer ring 11 of the clutch inner ring 12 and both ends of the inner diameter surface of the pulley 1. The pair of rolling bearings 20 is incorporated in the pulley 1, and the pulley 1 and the clutch inner ring 12 are relatively rotatably supported by the rolling bearing 20.

  The pair of rolling bearings 20 is composed of a single seal bearing in which a seal 23 is attached between one end portions of a bearing outer ring 21 and a bearing inner ring 22, and a cage that holds the rolling elements 24 of the one rolling bearing 20 is the one-way clutch 10. It is integrated with the cage 13.

  Recesses 18a and 18b extending in the axial direction are formed on the outer diameter surface and the inner diameter surface of the column portion 17 formed between the pockets 14 of the cage 13 in the one-way clutch 10, and the recesses 18a and 18b are formed in the recesses 18a and 18b. A solid lubricant 19 is contained in the container.

  The solid lubricant 19 is obtained by mixing ultra-high molecular polyethylene with lubricating grease or lubricating oil, and solidifying. The base oil infiltrating the surface of the solid lubricant 19 causes the sprag 15, the clutch outer ring 11, and the clutch inner ring 12. The contact part is lubricated.

  In the pulley with a built-in clutch configured as described above, when driving the alternator as an engine accessory, the clutch inner ring 12 is attached to the rotating shaft of the alternator, and the belt is passed between the pulley 1 and the pulley attached on the crankshaft. Thus, the rotation of the crankshaft is transmitted to the pulley 1.

  When the pulley 1 is rotated in the direction indicated by the arrow in FIG. 2 in the above-described use state, the sprag 15 swings in a direction to stand by contact with the cylindrical inner surface 11a of the clutch outer ring 11, and The cam surfaces 15 a and 15 b engage with the cylindrical inner surface 11 a of the clutch outer ring 11 and the cylindrical outer surface 12 a of the clutch inner ring 12, and the rotation of the pulley 1 is transmitted to the clutch inner ring 12 through the sprags 15.

  When the rotational speed of the clutch inner ring 12 exceeds the rotational speed of the pulley 1 during transmission of the rotational torque from the pulley 1 to the clutch inner ring 12, the sprag 15 is caused by the relative rotational speed difference between the clutch inner ring 12 and the clutch outer ring 11. The elastic member 16 is rocked in the direction of falling in the circumferential direction against the elasticity of the elastic member 16, and the engagement with the cylindrical outer surface 12 a of the clutch inner ring 12 and the cylindrical inner surface 11 a of the clutch outer ring 11 is released.

  For this reason, the rotation transmission from the pulley 1 to the clutch inner ring 12 is cut off, the pulley 1 rotates freely, the relative slip between the pulley 1 and the belt hung on the pulley 1 is prevented, and the belt Wear is prevented from occurring.

  Here, when the pulley 1 rotates freely, the clutch outer ring 11 and the clutch inner ring 12 rotate relative to each other. At this time, the bearing outer ring 21 and the bearing inner ring 22 of the rolling bearing 20 also rotate relative to each other, and the rolling element 24 revolves by a half of the relative rotation amount of the bearing outer ring 21 and the bearing inner ring 22. The cage that holds the rolling elements 24 also rotates.

  Since the cage of one rolling bearing 20 is integrated with the cage 13 of the one-way clutch 10, the cage 13 in the one-way clutch 10 and the sprag 15 held by the cage 13 also rotate. become.

  At this time, if the one-way clutch 10 is lubricated by the grease enclosed between the clutch outer ring 11 and the clutch inner ring 12, the grease is agitated and sheared as described above. Becomes higher.

  However, in the embodiment, the solid lubricant 19 is accommodated in the recesses 18a and 18b formed in the column portion 17 of the cage 13, and the one-way clutch 10 is lubricated by the solid lubricant 19, There is no shear resistance of grease as described above, and idling is possible with low torque, and idling torque can be reduced.

  Further, the base oil infiltrates into the surface of the solid lubricant 19 due to heat generation and centrifugal force of the one-way clutch 10, and the base oil lubricates the contact portion between the sprag 15, the clutch outer ring 11, and the clutch inner ring 12. Wear at the contact portion can be prevented, and a reduction in clutch life can be suppressed.

  In the embodiment, the recess portion 18 is formed in the column portion 17 of the cage 13 and the solid lubricant 19 is accommodated in the recess portion 18. However, the housing position of the solid lubricant 19 is not limited to this, and the sprag 15 Any position may be used as long as it does not hinder the behavior. For example, it may be incorporated in an axial pocket gap formed between the pocket 14 and the sprag 15.

  Here, the solid lubricant 19 is accommodated in a space that does not hinder the rolling of the rolling elements 24 in the pair of rolling bearings 20, and the rolling bearing 20 is lubricated, whereby a clutch having a smaller idling torque is obtained. A built-in pulley can be obtained.

  Although the sprag type one-way clutch is shown as the one-way clutch 10 in the embodiment, the one-way clutch is not limited to the sprag type, and a cylindrical surface is provided on one of the inner periphery of the clutch outer ring and the outer periphery of the clutch inner ring. Forming a cam surface that forms a wedge-shaped space with the cylindrical surface on the other side, forming a pocket at a position facing the cam surface of the cage built between the cam surface and the cylindrical surface, It may be a roller type one-way clutch incorporating a roller in the pocket and an elastic member that biases the roller toward a narrow portion of the wedge-shaped space.

Longitudinal front view of clutch built-in pulley using one-way roller clutch according to the present invention Sectional view along the line II-II in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pulley 10 One-way clutch 11 Clutch outer ring 12 Clutch inner ring 13 Cage 14 Pocket 15 Sprag 16 Elastic member 17 Column part 18a Recessed part 18b Recessed part 19 Solid lubricant 20 Rolling bearing

Claims (3)

A clutch outer ring, a clutch inner ring incorporated inside the clutch outer ring, a cage incorporated between the clutch inner ring and the clutch outer ring, and a plurality of spaces formed in the circumferential direction of the cage And an elastic member that biases the engagement element in a direction to engage with the inner periphery of the clutch outer ring and the outer periphery of the clutch inner ring, and one of the clutch outer ring and the clutch inner ring. The engagement element is engaged with the inner periphery of the clutch outer ring and the outer periphery of the clutch inner ring by relative rotation in the direction to transmit the rotational torque between the clutch outer ring and the clutch inner ring, and is filled between the clutch outer ring and the clutch inner ring. In the one-way clutch in which the contact portion between the engagement element, the clutch outer ring and the clutch inner ring is lubricated by the lubricant,
The lubricant is composed of a solid lubricant obtained by mixing a lubricant grease or a lubricant with ultra high molecular weight polyethylene, and the solid lubricant is accommodated in a space that does not hinder the behavior of the engagement element. One way clutch.   The one-way clutch according to claim 1, wherein a recess is formed in each of an inner diameter surface and an outer diameter surface of a pillar portion formed between pockets of the cage, and a solid lubricant is accommodated in the recess.   A pulley with a built-in clutch in which a one-way clutch is incorporated inside a pulley and rolling bearings are incorporated on both sides thereof, wherein the one-way clutch comprises the one-way clutch according to claim 1 or 2. .

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