JP4494086B2 - One-way clutch - Google Patents

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 rotation shafts of various auxiliary machines such as a hydraulic pump of a power steering system, 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 block 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 disposed in the engine room, is rotated at a high speed, and 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, during the idling, the engagement element, the inner ring and the outer ring rotate relative to each other while sliding at the contact portion. Therefore, the grease on the front side in the rotation direction of the engagement element is the engagement 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 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, a plurality of engagement elements that engage with the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring to couple the two wheels, a retainer that holds the engagement elements, and the engagement elements that are connected to the inner periphery of the outer ring. A one-way clutch comprising: an elastic member energizing in a direction to engage the outer surface of the surface and the inner ring, wherein the contact portion between the engagement element and the outer ring and the inner ring is lubricated by grease filled between the outer ring and the inner ring The flange is provided on both sides in the axial direction of at least one of the outer peripheral surface and the inner peripheral surface of the cage, and grease is pressed in the circumferential direction on the inner surface of each flange during relative rotation of the cage with respect to the outer ring and the inner ring. Cage width direction Than is adopted the structure in which a plurality of protrusions gather the central.

  It is preferable to provide the protrusions at positions corresponding to the adjacent engagement elements so that substantially uniform lubricity can be obtained at the contact parts of the engagement elements and the outer ring and the inner ring.

  Here, the engaging elements arranged in the circumferential direction of the cage are arranged in a staggered manner in the circumferential direction of the cage by shifting the position in the axial direction with respect to the adjacent engaging elements. One protrusion is provided on the inner surface of each flange so that each protrusion is arranged in a staggered manner in the circumferential direction of the cage, and the protrusion provided on each flange is shifted to the flange side. By facing the engaged member in the circumferential direction of the cage, the grease with the protruding portion brought close to the center in the width direction of the cage can be effectively guided to the contact portion between the engagement member, the outer ring, and the inner ring.

  Moreover, since the number of protrusions can be reduced as compared with the case where a pair of protrusions facing each other between the engagement elements in the cage axial direction is provided, as a grease reservoir formed between the pair of flanges The volume of the space can be expanded. For this reason, a large amount of grease can be held.

  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 easily incorporate the one-way clutch into the belt transmission device by press-fitting a pulley around the outer ring to form a unit.

  As described above, since the flange is provided on at least one of the outer peripheral surface and the inner peripheral surface of the cage, the grease that flows on both sides in the axial direction due to the pressing of the engagement element when the one-way clutch idles is It is possible to prevent the grease from being removed, and the grease can be retained between the pair of flanges.

  For this reason, the retainability of grease is excellent, and the contact portion between the engagement element, the outer ring and the inner ring can be well lubricated by the retained 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 protrusion on the inner surface of the flange, the grease is directed toward the center in the width direction of the cage by the pressing of the protrusion when the one-way clutch rotates relative to the outer ring and the inner ring. Can be made to flow. For this reason, the contact part of an engagement element, an outer ring | wheel, and an inner ring | wheel can be lubricated favorably, and lubricity can be improved more.

  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 biasing 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 element 13 is disposed between the cylindrical surface 16 of the outer ring 11 and the cylindrical surface 17 of the inner ring 12 with a gap in the circumferential direction.

  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 21 for individually accommodating the engaging elements 13 and spring accommodating recesses 22 communicating with the pockets 21. An elastic member 15 made of a spring is incorporated in the housing recess 22. 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 the rotational torque of the outer ring 11 is increased. 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 FIGS. 3 and 4, flanges 23 are provided on both sides of the outer peripheral surface of the cage 14 in the axial direction. A protrusion 24 is formed on the inner surface of the flange 23 at a position corresponding to between the adjacent engagement elements 13. The protruding portion 24 presses the accumulated grease and moves it toward the center in the width direction of the retainer 14 when the retainer 14 rotates idly with respect to the outer ring 11 and the inner ring 12.

  In the embodiment, the outer peripheral pressing surface 24a that presses the grease of the protruding portion 24 is an arc surface, but the pressing surface 24a may be any material that can bring the grease to the center in the width direction of the cage 14, It is not limited to the arc surface. For example, it may have a mountain shape composed of two tapered surfaces inclined in opposite directions to the pressing surface 24a.

  As shown in FIG. 1, one end of the cage 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 can 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 rotates 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 clutch as described above is attached to the rotating shaft of the alternator, for example, and the belt is passed between the pulley attached to the crankshaft and the pulley on the rotating shaft, the alternator is driven. 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 idles, the double-row engagement elements 13 rotate relative to the outer ring 11 and the inner ring 12. At this time, the engaging element 13 revolves together with the cage 14 while sliding on the cylindrical surface 16 of the outer ring 11 and the cylindrical surface 17 of the inner ring 12, so that the grease is pushed by the engaging element 13 toward both axial sides of the cage 14. To flow.

  Grease flowing on both sides in the axial direction on the inner peripheral surface side of the cage 14 enters the bearing 19 and lubricates the bearing 19. On the other hand, the grease flowing in the axial direction on the outer peripheral surface side of the cage 14 is prevented from leaking from the inside of the one-way clutch 10 to the outside by the flanges 23 provided on both axial sides of the outer peripheral surface. For this reason, the grease accumulates and is retained between the revolution trajectories of the flanges 23 and the engagement elements 13.

  As described above, since the flanges 23 are provided on both axial sides of the outer circumferential surface of the cage 14, it is possible to prevent grease on the outer circumferential surface side of the cage from being removed outward of the one-way clutch 10. The retaining property of the grease can be enhanced, and the contact portion between the engagement element 13 and the cylindrical surface 16 can be lubricated by the retained grease. Therefore, wear and heat generation at the contact portion can be prevented, and grease deterioration due to heat generation can be prevented.

  Further, since the protrusion 24 is provided on the inner surface of the flange 23, the grease accumulated by the protrusion 24 can be pressed and brought to the center in the width direction of the cage 14. For this reason, the contact part of the engaging element 13 and the cylindrical surface 16 can be lubricated more effectively.

  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 shown in FIG. 3, the flange 23 is provided only on the outer peripheral surface of the retainer 14. However, the flange 23 may be provided only on the inner peripheral surface of the retainer 14, or the outer peripheral surface and the inner periphery. A pair of flanges 23 may be provided on both surfaces. By providing the flanges 23 on both axial sides of the outer peripheral surface and the inner peripheral surface, it is possible to further improve the grease retention, and to effectively lubricate the contact portions between the engagement element 13 and the cylindrical surfaces 16 and 17. be able to.

  As shown in FIGS. 5 (a) and 5 (b), the adjacent engaging elements 13 are shifted in the cage axial direction so that the plurality of engaging elements 13 are arranged in a staggered manner in the circumferential direction of the cage. Each protrusion 13 is provided with one protrusion 24, and each protrusion 24 is provided on each flange 23 so that each protrusion 24 is arranged in a staggered manner in the circumferential direction of the cage 14. Each of the protruding portions 24 is opposed to the engaging element 13 that is shifted toward the flange 23 in the circumferential direction of the cage, so that the grease that is moved toward the center in the width direction of the cage 14 by the protruding portion 24 is engaged. It becomes easy to flow to the axial direction center part of the combination 13, and the contact part of the engagement element 13 and the cylindrical surfaces 16 and 17 can be lubricated effectively.

  Further, since the number of protrusions 24 can be reduced as compared with the case shown in FIG. 4, the volume of the space as a grease reservoir formed between the pair of flanges 23 can be increased, so The amount can be increased.

  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 in which 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. (A) and (B) are plan views showing other examples of the cage.

Explanation of symbols

1 Pulley 11 Outer Ring 12 Inner Ring 13 Engagement Element 14 Cage 15 Elastic Member 23 Flange 24 Projection

Claims (5)

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 engaging members that engage with the outer peripheral surface of the inner ring to couple the two wheels, a cage that holds the engaging members, and a biasing force in the direction in which the engaging members are engaged with the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring. In a one-way clutch that lubricates a contact portion between the outer ring and the inner ring with grease filled between the outer ring and the inner ring, at least of the outer peripheral surface and the inner peripheral surface of the cage. Provide flanges on both sides in the axial direction of one surface, and in the circumferential direction on the inner surface of each flange, there are a plurality of protrusions that press grease at the relative rotation of the cage with respect to the outer ring and the inner ring and bring them closer to the center in the width direction It is characterized in that it is provided The one-way clutch. The one-way clutch according to claim 1, wherein the protruding portion is provided at a position corresponding to between adjacent engaging elements . The engaging elements arranged in the circumferential direction of the cage are arranged in a staggered manner in the circumferential direction of the cage by shifting the position in the axial direction with respect to the adjacent engaging elements, and one engaging element is provided between the adjacent engaging elements. The protrusions are provided on the inner surface of each flange so that the protrusions are arranged in a staggered manner in the circumferential direction of the cage, and the protrusions provided on the flanges are shifted to the flange side. The one-way clutch according to claim 1 or 2, wherein the clutch is opposed to the cage in the circumferential direction . The one-way clutch according to any one of claims 1 to 3, wherein the cage is a molded product of a synthetic resin . The one-way clutch according to any one of claims 1 to 4, wherein a pulley is press-fitted into an outer peripheral surface of the outer ring .

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