JP2006097712A - One-way clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a one-way clutch capable of promoting circulation of grease and solving a problem wherein grease at the outer periphery of an inner ring becomes dilute. <P>SOLUTION: A plurality of pockets 15b for a grease conveying member are provided in addition to a plurality of pockets 15a for a meshing member storing a roller 13 as a meshing member in a cage 15. A roller 16 for conveying grease for conveying the grease adhered to the inner periphery of an outer ring onto an inner ring side by rolling is stored in the pocket 15b for the grease conveying member. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a one-way clutch suitable for use in, for example, a belt drive starter or an alternator in a belt transmission system for transmitting a rotational force by a belt when starting an internal combustion engine and driving an auxiliary machine by the internal combustion engine.

  An inner ring, an outer ring, a roller as a plurality of biting members arranged between both wheels, a biasing member for biasing each roller in the biting direction, and a one-way clutch provided with a cage for holding the plurality of rollers are shown in FIG. As shown in FIG. 3, it is conventionally known (Patent Document 1).

The one-way clutch (5) includes a cam surface (11) composed of a plurality of parallel two surfaces (11a) (11b) (11c) (11d) provided on the inner peripheral surface of the pulley (4), and a cam surface ( 11) and the wedge-shaped space (12) formed by the outer peripheral surface of the hollow shaft (3), and the hollow shaft (3) and the pulley (4) rotate relatively in one direction (locking direction). Roller (13) as a plurality of biting members that are engaged between the hollow shaft (3) and the pulley (4) and release the engagement when rotated relative to the other direction (free direction), A coil spring (14) as a biasing member that biases 13) in the biting direction (narrow side of the wedge-shaped space (12)) and a cage (15) that positions the roller (13) in the wedge-shaped space (12) ). In this type of one-way clutch (5), lubrication is performed with grease.
JP2003-156075A

  The one-way clutch described in Patent Document 1 has a problem that the grease on the outer periphery of the inner ring tends to become thin because the grease easily moves to the inner periphery of the outer ring by being rotated at a high speed.

  An object of the present invention is to provide a one-way clutch that solves the problem that the circulation of grease is promoted and the grease on the outer periphery of the inner ring tends to become thin.

  A one-way clutch according to the present invention includes an inner ring, an outer ring, rollers as a plurality of engagement members disposed between both wheels, an urging member that urges each roller in the engagement direction, and a cage that holds the plurality of rollers. In the one-way clutch provided, the cage is provided with a plurality of pockets for the grease conveying member in addition to the plurality of pockets for the biting member in which the rollers as the biting members are accommodated. In addition, a rolling element that conveys the grease adhering to the inner periphery of the outer ring by rolling to the inner ring side is housed.

  The one-way clutch is disposed in a wedge-shaped space formed by a cam surface provided on the inner peripheral surface of the outer ring and the cam surface and the outer peripheral surface of the inner ring, and the inner ring and the outer ring are in one direction (locking direction). Roller as a plurality of biting members that bite between the inner ring and the outer ring by relative rotation and release the biting when rotated relative to the other direction (free direction), and the roller biting direction (wedge-like space) A coil spring as a biasing member for biasing to the narrow side) and a cage for positioning the roller in the wedge-shaped space (outer ring cam type), and may be provided on the outer peripheral surface of the inner ring Are arranged in a wedge-shaped space formed by the cam surface, the cam surface and the inner peripheral surface of the outer ring, and the inner ring and the outer ring are relatively rotated in one direction to be engaged between the inner ring and the outer ring. Release the bite when rotating in the direction of And rollers as members biting number, (narrow side of the wedge-shaped space) to bias and a coil spring as an urging member (inner ring cam type) biting direction rollers that is.

  The plurality of biting member pockets and the plurality of grease conveying member pockets are formed alternately, for example, and a grease conveying rolling element is provided around the grease conveying rolling element so as to be able to roll. A gap is formed. The number of rollers as the biting member is not necessarily the same as the number of rolling elements for conveying grease. The rolling element for conveying grease is, for example, a resin roller for weight reduction. In order to increase the amount of grease to be adhered, the roller surface is preferably formed to be rough, for example, by providing grooves and irregularities. Further, it is preferable that the rolling element for conveying grease is in a light contact state with the inner ring and the outer ring, and it is preferable that a radial clearance exists between the inner ring and the outer ring when incorporated in the one-way clutch.

  Moreover, it is preferable that a recess for grease storage is provided on the inner peripheral portion of the outer ring facing the grease transport member pocket. The grease reservoir recess has, for example, an arc shape whose cross section is the same as or slightly larger than the diameter of the rolling element for conveying grease.

  The one-way clutch is used as a pulley unit with a one-way clutch in which the one-way clutch is arranged between a shaft and a pulley arranged concentrically around the shaft, and rolling bearings are arranged on both sides thereof. It is suitable for. In this case, the one-way clutch may have an outer ring that is a member different from the pulley and an inner ring that is a member different from the hollow shaft, and an intermediate portion of the pulley is an outer ring of the one-way clutch. At the same time, the middle part of the hollow shaft may be the inner ring of the one-way clutch. In the case of the former (the outer ring and inner ring of the one-way clutch are separate members from the pulley or hollow shaft), for example, the inner diameter of the pulley is the same except for the annular groove portion for hermetic seal, and the outer ring of the bearing is Axial positioning is performed by contacting the outer ring of the one-way clutch. The outer diameter of the hollow shaft is the same except for the annular groove portion for hermetic sealing, and the inner ring of the bearing is positioned in the axial direction by contacting the inner ring of the one-way clutch during press-fitting. In the latter case (the pulley also serves as the outer ring of the one-way clutch and the hollow shaft also serves as the inner ring), for example, the inner diameter of the pulley is formed in a stepped shape in which both ends are larger in diameter than the intermediate part. The outer ring is positioned by the step portion of the pulley, and the inner ring of the bearing is positioned by positioning the outer ring.

  According to the one-way clutch of the present invention, the grease conveying rolling element that conveys the grease adhering to the inner periphery of the outer ring by rolling to the pocket of the grease conveying member is disposed in the pocket for the grease conveying member. A large amount of grease that tends to concentrate on the outer ring outer periphery due to centrifugal force adheres to the grease transfer rolling element at the outer ring outer periphery, and the grease transfer roller rolls to transfer the grease attached to the outer ring outer periphery to the outer ring outer periphery. As a result, the circulation of grease is promoted, and the amount of grease existing on the outer periphery of the inner ring is ensured. As a result, wear and impact due to the engagement between the rollers as the biting member and the inner ring are suppressed, and the meshing part peeling life is improved.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the left and right refer to the left and right in FIG.

  FIG. 1 shows the overall configuration of a pulley unit using a one-way clutch according to the present invention.

  A pulley unit (1) with a one-way clutch is disposed, for example, in a portion that connects an engine drive unit and a rotation shaft of a starter motor, and a hollow shaft (2) fitted to the rotation shaft (2) of the starter motor. A one-way clutch (3) and a pulley (4) arranged concentrically around it to lock or free torque transmission between the hollow shaft (3) and the pulley (4) ( 5) and rolling bearings (6) and (7) provided on at least one side in the axial direction of the one-way clutch (5) (both sides in this embodiment).

  On the outer periphery of the pulley (4), there is provided a belt spanning portion (4a) on which the V-ribbed belt (B) is spanned.

  The one-way clutch (5) is provided between the hollow shaft (3) and the intermediate portion in the axial direction of the pulley (4), and is located between the hollow shaft (3) and a portion near each end of the pulley (4). A roller bearing (6) whose rolling element is a roller (6a) and a ball bearing (7) whose rolling element is a ball (7a) are provided with a one-way clutch (5) interposed therebetween. The outer ring of the pulley (4) and the one-way clutch (5) and the outer ring of the bearings (6) and (7) are integrated, and the inner ring and the bearing of the hollow shaft (3) and the one-way clutch (5) ( 6) The inner ring of (7) is integrated.

  Seal members (8) and (9) are arranged on the outer sides in the axial direction of the roller bearing (6) and the ball bearing (7), respectively, and on the free end side (the left end side in the figure) of the pulley unit, the pulley unit In order to prevent intrusion of muddy water or the like inside, another seal member (10) is arranged.

  The inner diameter of the pulley (4) is stepped, the inner diameter of the outer ring raceway portion of the roller bearing (6) is D1, the minimum inner diameter of the outer ring of the one-way clutch (5) (in this embodiment, the outer ring cam surface (11 D2> D2 ≧ D3, where D2 is the distance between the two surfaces)) and D3 is the inner diameter of the outer ring raceway shoulder of the ball bearing (7). The outer diameter of the hollow shaft (3) is constant except for the groove, and the inner ring raceway outer diameter of the roller bearing (6) = the inner ring outer diameter of the one-way clutch (5) = the ball bearing (7). The outer diameter of the outer ring raceway shoulder.

  As shown in FIG. 2, the one-way clutch (5) includes an outer ring cam surface (11) provided on an inner peripheral surface of a pulley (4) as an outer ring, a cam surface (11), and a hollow shaft ( A roller (13) as a plurality of (for example, six) biting members disposed in a wedge-shaped space (12) formed by the outer peripheral surface of 3) and a roller (13) in the biting direction (wedge-shaped space ( A coil spring (14) as an urging member for urging to the narrow side of 12), a cage (15) for positioning the roller (13) in the wedge-shaped space (12), and a plurality (for example, six) of And a grease conveying roller (16) as a grease conveying rolling element.

  The cage (15) is made of synthetic resin and has an outer peripheral shape substantially along the cam surface (11) and an inner peripheral shape along the outer peripheral surface of the hollow shaft (3), and within the cam surface (11). It is press-fitted. A slight gap is provided between the cage (15) and the outer periphery of the hollow shaft (3).

  The cage (15) is provided with a plurality of biting member pockets (15a) for accommodating the rollers (13) and the coil spring (14), and the interval between adjacent biting member pockets (15a) is set. A plurality of grease carrying member pockets (15b) for accommodating the grease carrying rollers (16) are provided between adjacent biting member pockets (15a) which are larger than the conventional ones. Each pocket (15a) (15b) is filled with grease.

  The grease (outer ring) (4) facing the pocket (15b) for the grease conveying member has an inner periphery with a gap that allows the grease conveying roller (16) to roll. The reservoir recess (17) is provided, and the grease transport roller (16) rolls into the grease transport member pocket (15b) so that it is in light contact with the inner ring (3) and the outer ring (4). It is stored as possible. Therefore, when the hollow shaft (inner ring) (3) rotates, a tangential force acts on the grease carrying roller (16) from the inner ring (3), the grease carrying roller (16) rolls, and the outer ring (4 ) Grease adhering to the inner circumference is conveyed to the inner ring (3) side by the rolling of the rollers (16).

  Note that the grease conveying roller (16) does not require strength as compared with the roller (13) as the biting member, and is therefore made of a synthetic resin, thereby reducing the weight. Further, the surface of the grease carrying roller (16) is preferably formed to be rough in order to increase the amount of grease that adheres. In addition, the size of the grease transfer roller (16) is such that there is a radial clearance between the roller (16) and the inner ring (3) and outer ring (4) when installed in the one-way clutch (5). It is preferable.

  This one-way clutch operates as follows.

  First, at the time of starting, the hollow shaft (3) integrated with the rotation shaft (2) of the starter motor is rotated counterclockwise. As a result, the hollow shaft (3) of the one-way clutch (5) rotates counterclockwise, and the roller (13) is engaged with the narrow side of the wedge-shaped space (12) of the one-way clutch (5), and the driving force Is transmitted, and the hollow shaft (3) and the pulley (4) of the one-way clutch (5) rotate together (locked state). The pulley (4) is connected to the crankshaft via a belt, and the engine is started by the rotation of the pulley (4). When the engine starts, the starter stops and the pulley (4) continues to rotate counterclockwise. As a result, the engagement of the roller (13) is released, and the state in which only the pulley (4) rotates continues, and the roller (13) is not in contact with the hollow shaft (3) during high-speed rotation of the engine. (Free state). Thus, when the pulley (4) reaches a predetermined rotational speed or higher, only the pulley (4) rotates, and energy loss due to rotation of a portion that does not contribute to driving of the engine can be suppressed.

  The grease sealed in the cage (15) tends to concentrate on the inner periphery of the pulley (4) as the one-way clutch (5) rotates at high speed. The roller (13) as the biting member is in the biting state and does not rotate when locked, and is stuck to the inner periphery of the pulley (4) when free, and in this case also does not roll. Therefore, the grease is not circulated to the hollow shaft (3) side by the rollers (13) as the biting members. On the other hand, the grease conveying roller (16) can roll both when the one-way clutch (5) is free and when locked, thereby promoting the circulation of grease.

FIG. 1 is a longitudinal sectional view showing an embodiment of a one-way clutch according to the present invention. FIG. 2 is a partially enlarged view of a cross section of the one-way clutch. FIG. 3 is a cross-sectional view showing a conventional one-way clutch.

Explanation of symbols

(3) Hollow shaft (inner ring)
(4) Pulley (outer ring)
(5) One-way clutch
(13) Roller (biting member)
(14) Coil spring (biasing member)
(15) Cage
(15a) Biting member pocket
(15b) Grease transfer material pocket
(16) Grease conveying roller (Grease conveying rolling element)
(17) Recess for grease reservoir

Claims (2)

In the one-way clutch comprising an inner ring, an outer ring, rollers as a plurality of biting members disposed between both wheels, a biasing member that biases each roller in the biting direction, and a cage that holds the plurality of rollers,
The cage is provided with a plurality of pockets for a grease conveying member in addition to a plurality of pockets for a biting member in which a roller as a biting member is accommodated, and by rolling to the pocket for the grease conveying member A one-way clutch comprising a rolling element for conveying grease adhering to an inner periphery of an outer ring to the inner ring side.   The one-way clutch according to claim 1, wherein a recess for storing a grease is provided in an inner peripheral portion of the outer ring facing the grease conveying member pocket.

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