JP2005321022A - One-way clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a one-way clutch having excellent retaining and lubricating performance of grease. <P>SOLUTION: A plurality of engagement elements 13 provided at spaces in the circumferential direction, a retainer 14 retaining the respective engagement elements 13, and an elastic member 15 energizing the engagement elements 13 in the engaging direction are assembled between an outer ring 11 and an inner ring 12. A plurality of engagement elements 13 provided at spaces in the circumferential direction are provided at spaces in the axial direction of an outer and inner rings in two or more rows, whereby during racing of the one-way clutch, grease moving inward in the axial direction of the grease pressed inward in the axial direction is caused to stay by the two or more rows of engagement elements 13 to improve the retaining performance of grease. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a one-way clutch that transmits and shuts off rotational torque.

  Generally, driving energy is generated in an automobile engine during an explosion stroke, so that an angular velocity of a crankshaft driven by the engine changes during one rotation.

  For this reason, the rotation of the crankshaft is transmitted to the rotating shafts of various auxiliary machines such as a hydraulic pump of a power steering apparatus, a compressor of an air conditioner, or an alternator by a belt transmission to drive each auxiliary machine. In the machine drive device, due to the change in the angular velocity of the crankshaft, slippage occurs between the belt and the pulley, and the belt is easily worn. In particular, in an alternator having a large inertial force, slippage is likely to occur between a pulley and a belt mounted on the rotating shaft.

  In order to eliminate such inconvenience, in the accessory driving device described in Patent Document 1, a one-way clutch is incorporated between the rotating shaft of the accessory and a pulley provided on the rotating shaft, and the crankshaft When the angular velocity increases, the rotating shaft and pulley are coupled to transmit the rotation of the crankshaft to the rotating shaft, and when the angular velocity decreases, the one-way clutch is overrun to interrupt transmission of rotational torque from the crankshaft to the rotating shaft. The belt is prevented from slipping.

  As described in Patent Document 2, as a one-way clutch employed in an accessory drive device, a sprag type one-way clutch in which an engaging member incorporated between an outer ring and an inner ring is formed of a sprag, A roller type one-way clutch composed of rollers is known.

The one-way clutch as described above is grease-lubricated in use, but is placed in the engine room, rotated at a high speed, and because the idling of the one-way clutch is large during sudden deceleration, If the grease lubrication is insufficient, wear or heat generation occurs at the contact portion between the outer ring and the engaging member and the contact portion between the inner ring and the engaging member.
JP-A-61-2228153 JP 2001-187931 A

  By the way, in the conventionally known one-way clutch, the engaging element, the inner ring, and the outer ring rotate relative to each other while slipping at the contact portion at the time of idling, so that the grease on the front side in the rotating direction of the engaging element is the above engaging element. There is a problem in that it is pushed and removed on both sides in the axial direction of the engaging element, and the lubricity is deteriorated at the contact portion between the engaging element and the outer / inner ring. In particular, there has been a problem that poor lubrication is likely to occur at the central portion in the axial direction of the engagement element and wear easily.

  An object of the present invention is to provide a one-way clutch having excellent grease retention and lubricity.

  In order to solve the above problems, in the present invention, an outer ring, an inner ring that is rotatable relative to the outer ring, and a circumferential interval between the outer ring and the inner ring are arranged, and the outer ring and the inner ring are arranged. When relatively rotating in one direction, the outer ring inner peripheral surface and a plurality of engaging members that engage with the outer peripheral surface of the inner ring to couple the two wheels, a retainer that holds the engaging members, and the engaging members that are connected to the inner peripheral surface of the outer ring And a one-way clutch configured to lubricate a contact portion between the outer ring and the inner ring with grease filled between the outer ring and the inner ring. A configuration is adopted in which a plurality of engagement elements arranged in the circumferential direction between the outer ring and the inner ring are provided in a double row at intervals in the axial direction of both wheels.

  Here, in order to further enhance the grease retention, a grease reservoir comprising a recess is provided between at least one of the inner circumference of the outer ring and the outer circumference of the inner ring, or the outer circumference and the inner circumference of the cage are arranged between the double-row engagement elements. At least one of them is provided with a grease reservoir comprising a recess. As the grease reservoir, one having a circumferential groove can be adopted.

  In the one-way clutch according to the present invention, if the cage is a synthetic resin molded product, it is easy to manufacture and the cost of the one-way clutch can be reduced.

  In addition, it is possible to facilitate the incorporation of the one-way clutch into the belt transmission device by pressing the pulley into the outer periphery of the outer ring to form a unit.

  As described above, by providing a plurality of engagement elements provided at intervals in the circumferential direction between the outer ring and the inner ring in a double row, when the one-way clutch is idling, it escapes to the central part in the axial direction by the pressing of the engagement element. Since the grease stays between the double-row engagement elements, it is possible to enhance the retention of the grease, and the contact area between the engagement elements and the inner and outer rings can be well lubricated by the accumulated grease. Therefore, wear and heat generation at the contact portion can be prevented, and deterioration of grease can be suppressed by suppressing heat generation.

  In addition, by providing a grease reservoir on the inner circumference of the outer ring, the outer circumference of the inner ring, or the inner and outer circumference of the cage between the double-row engagement elements, the amount of accumulated grease is increased and the grease retention is further improved. Can do.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2 show a pulley with a built-in clutch in which a one-way clutch 10 according to the present invention is incorporated in a pulley 1. The one-way clutch 10 includes an outer ring 11 press-fitted into the inner diameter surface of the pulley 1, an inner ring 12 incorporated inside the outer ring 11, an engagement element 13 incorporated between the two rings 11, 12, and the engagement element A retainer 14 for holding 13 and an elastic member 15 for urging the engaging element 13 in the engaging direction.

  The outer ring 11 has a shorter axial length than the inner ring 12, and a cylindrical surface 16 is formed on the inner periphery of the outer ring 11.

  A cylindrical surface 17 is formed on the outer periphery of the inner ring 12 so as to face the cylindrical surface 16 of the outer ring 11 in the radial direction. Further, on the outer periphery of the inner ring 12, bearing fitting surfaces 18 are formed on both sides of the cylindrical surface 17, and a bearing 19 is supported on each bearing fitting surface 18.

  The bearing 19 is a ball bearing with a single seal. The bearing 19 is assembled so that the seal 20 is located on the outer side, and the pulley 1 and the inner ring 12 are relatively rotatable by the bearing 19. Grease is sealed between the outer ring 11 and the inner ring 12 between the pair of bearings 19.

  The engagement element 13 is made of a sprag. The engagement elements 13 are arranged between the cylindrical surface 16 of the outer ring 11 and the cylindrical surface 17 of the inner ring 12 at intervals in the circumferential direction, and are arranged in a double row at intervals in the axial direction. Between the engagement elements 13, grease reservoirs 21 and 22 each including a circumferential groove are provided on the cylindrical surface 16 of the outer ring 11 and the cylindrical surface 17 of the inner ring 12.

  The cage 14 is made of a synthetic resin molded product. As shown in FIGS. 2 to 4, the retainer 14 is formed with a plurality of pockets 23 for individually accommodating the double-row engagement elements 13 and spring accommodating recesses 24 communicating with the pockets 23. In each spring accommodating recess 24, an elastic member 15 made of a spring is incorporated. The elastic member 15 biases the engaging element 13 in a direction in which the engaging element 13 engages with the cylindrical surface 16 of the outer ring 11 and the cylindrical surface 17 of the inner ring 12.

  Here, when the outer ring 11 together with the pulley 1 rotates relative to the inner ring 12 in the direction of the arrow in FIG. 2, the engaging element 13 engages with each cylindrical surface 16, 17, and applies the rotational torque of the outer ring 11 to the inner ring 12. To communicate. Further, in the engaging element 13, the outer ring 11 rotates relative to the inner ring 12 in the opposite direction indicated by the arrow, or the rotation speed of the inner ring 12 rotating in the same direction with respect to the outer ring 11 rotating in the arrow direction is the outer ring. When the rotation speed exceeds 11, the engagement with the cylindrical surfaces 16 and 17 is released, and the rotation transmission from the outer ring 11 to the inner ring 12 is cut off.

  As shown in FIG. 3, grease reservoirs 25 each including a circumferential groove are provided between the double row engagement elements 13 on the outer circumference and the inner circumference of the cage 14. As shown in FIG. 1, one end of the retainer 14 is located in one bearing 19 and holds the ball 19 a of the bearing 19.

  As described above, the retainer 14 of the one-way clutch 10 is held by the retainer 14 of the one-way clutch 10, so that the retainer 14 is rotated during the idling of the one-way clutch 10 in which the outer ring 11 rotates relative to the inner ring 12. Thus, the engaging member 13 rotating together with the retainer 14 can be slid relative to the cylindrical surface 16 of the outer ring 11 and the cylindrical surface 17 of the inner ring 12.

  The pulley with a built-in clutch shown in the embodiment has the above-described structure. In this pulley with a built-in clutch, when the pulley 1 is rotated in the direction of the arrow in FIG. 2, the engagement element 13 becomes the cylindrical surface 16 of the outer ring 11 and the cylindrical surface of the inner ring 12. 17, and the rotation of the pulley 1 is transmitted to the inner ring 12. When the rotation speed of the inner ring 12 exceeds the rotation speed of the outer ring 11, the engagement of the engaging elements 13 with respect to the cylindrical surfaces 16 and 17 is released, and the rotation transmission from the outer ring 11 to the inner ring 12 is interrupted.

  For this reason, when the pulley with a built-in clutch as described above is attached to the rotating shaft of the alternator and the belt is passed between the pulley attached to the crankshaft and the pulley on the rotating shaft to drive the alternator, the angular speed of the crankshaft At the time of increase, the one-way clutch 10 is engaged, and the rotation of the crankshaft is transmitted to the rotating shaft of the alternator.

  Further, when the angular velocity of the crankshaft is reduced, the one-way clutch 10 is in an idling state, and the rotation transmission from the crankshaft to the rotating shaft of the alternator is interrupted.

  For this reason, it is possible to prevent slippage between the pulley 1 and the belt applied thereto, and to suppress wear of the belt.

  Here, when the one-way clutch 10 rotates idly, the double row engaging elements 13 rotate relative to the outer ring 11 and the inner ring 12, and the grease on the front side in the rotating direction of each engaging element 13 is pressed by the engaging elements 13 to form a shaft. Move outward in the direction and inward in the axial direction.

  Grease that moves outward in the axial direction enters the bearing 19 and lubricates the bearing 19. On the other hand, the grease that has moved inward in the axial direction enters between the double-row engagement elements 13 and stays there, and is retained between the double-row engagement elements 13.

  Thus, by providing the engagement elements 13 provided in the circumferential direction between the outer ring 11 and the inner ring 12 in a double row, the grease can be held between the double row engagement elements 13. The contact portion between the engagement element 13 and the outer ring 11 and the inner ring 12 can be well lubricated by the retained grease. Therefore, wear and heat generation at the contact portion can be prevented, and deterioration of grease due to heat generation can also be prevented.

  Further, between the double-row engagement elements 13, grease reservoirs 21, 22, and 25 including circumferential grooves are provided on the outer peripheral surface of the cylindrical surface 16 of the outer ring 11, the cylindrical surface 17 of the inner ring 12, and the cage 13. Thus, the grease can be held in each of the grease reservoirs 21, 22, and 25, so that the grease retention can be further improved.

  As shown in the embodiment, when the cage 14 is a synthetic resin molded product, the manufacture becomes easy, and the cost of the one-way clutch 10 can be reduced.

  Further, by incorporating the one-way clutch 10 into the pulley 1 as a unit, it is possible to facilitate the incorporation into the belt transmission device.

  In the embodiment, as the one-way clutch 10, a sprag type one-way clutch in which the engaging element 13 is a sprag is shown, but the one-way clutch is not limited to this. For example, the engagement element 13 may be a roller type one-way clutch including a roller.

Longitudinal front view of a state where the one-way clutch according to the present invention is incorporated in a pulley Sectional view along the line II-II in FIG. Sectional drawing which expands and shows a part of FIG. Cross-sectional plan view of FIG.

Explanation of symbols

1 Pulley 11 Outer ring 12 Inner ring 13 Engagement element 14 Cage 15 Elastic members 21, 22, 25 Grease reservoir

Claims (6)

  An outer ring, an inner ring rotatable relative to the outer ring, and a circumferential interval between the outer ring and the inner ring, and when the outer ring and the inner ring rotate relatively in one direction, A plurality of engagement elements that engage with the outer peripheral surface of the inner ring to couple the two wheels, a cage that holds the engagement elements, and urge the engagement elements in a direction to engage with the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring. A one-way clutch composed of an elastic member and lubricating a contact portion between the engagement ring, the outer ring and the inner ring with grease filled between the outer ring and the inner ring, and a plurality of arrangements arranged in a circumferential direction between the outer ring and the inner ring The one-way clutch is characterized in that the engaging members are provided in a double row at intervals in the axial direction of both wheels.   2. The one-way clutch according to claim 1, wherein a grease reservoir comprising a concave portion is provided on at least one of an inner periphery of the outer ring and an outer periphery of the inner ring between the double-row engagement elements.   2. The one-way clutch according to claim 1, wherein a grease reservoir comprising a concave portion is provided between at least one of an outer periphery and an inner periphery of the cage between the engagement elements.   The one-way clutch according to claim 2 or 3, wherein the grease reservoir comprises a circumferential groove.   The one-way clutch according to any one of claims 1 to 4, wherein the retainer is formed of a synthetic resin molded product.   The one-way clutch according to any one of claims 1 to 5, wherein a pulley is press-fitted into an outer periphery of the outer ring.

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