JP2008032130A - One-way clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a one-way clutch allowing integral rotation of an engaging piece cage and a bearing cage and facilitating its assembly. <P>SOLUTION: This one-way clutch has such a configuration that a bearing part 5 having a plurality of steel balls 5a, a plurality of sprags 3, the engaging piece cage 4a for holding each sprag 3 in the peripheral direction, and the bearing cage 4b for holding the steel balls 5a in the bearing part 5 in the peripheral direction are arranged between an outer ring 1 and an inner ring 2, and the engaging piece cage 4a and the bearing cage 4b are formed separately from each other, can be mutually connected, and can rotate integrally due to their connection. Consequently, right and left supporting bearings can be used in common, the bearing cage which becomes a dummy when assembling a bearing is unnecessary, it is possible to dispense with mounting and dismounting of the dummy cage even when assembling one-way clutch, and the assembly of one-way clutch becomes easy. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

  In general, in an accessory drive device that transmits the rotation of a crankshaft of an engine of an automobile or the like to various accessories via a belt, the accessories such as a hydraulic pump of a power steering device and a compressor of an air conditioner, Alternatively, a one-way clutch is incorporated between a rotating shaft such as an alternator and a pulley provided on the rotating shaft.

  This one-way clutch couples the rotation shaft and pulley when the angular speed of rotation of the crankshaft increases and transmits the rotation of the crankshaft to the rotation shaft. When the angular speed decreases, the one-way clutch exceeds the one-way clutch. It functions to run and cut off the transmission of rotational torque from the crankshaft to the rotating shaft and prevent belt slippage.

  As a one-way clutch employed in this type of accessory drive device, a sprag type one-way clutch incorporating a number of "sprags" as engagement elements in the space between the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring. Is known (see, for example, Patent Document 1).

In the one-way clutch, as shown in FIG. 5, the outer ring 1 and the inner ring 2 are provided with bearing parts 5 having rolling elements 5 a arranged along the circumferential direction at both axial ends of the one-way clutch. And supported so as to be relatively rotatable about the axis.
In a space between the inner peripheral surface 1a of the outer ring 1 and the outer peripheral surface 2a of the inner ring 2, an annular cage 4a (hereinafter referred to as "engagement element") that keeps the circumferential distance between the adjacent engaging elements 3 and 3 constant. The retainer 4a "is provided), and the annular retainer 4b that keeps the circumferential distance between the adjacent rolling elements 5a and 5a constant on both sides in the axial direction of the engagement retainer 4a. (Hereinafter referred to as “bearing cage 4b”) is also provided.

The engagement holder 4a is formed integrally with at least one bearing holder 4b in the axial direction so that both the holders 4a and 4b rotate integrally.
For this reason, during the idling of the inner and outer rings 2 and 1, the respective engagement elements 3 are slid with respect to the outer ring 1, and the sliding speed of the respective engagement elements 3 with respect to the inner ring 2 is reduced, so that the cam surface of each engagement element 3 Of these, the cam surface on the side contacting the inner ring 2 is prevented from being excessively worn. (For example, refer to Patent Document 1 and Patent Document 2).
JP-A-2005-321022 JP 2001-187931 A

  In the one-way clutch, it is common to use bearings of the same size on the left and right, but in the one-way clutch of this configuration, one bearing is a general bearing, while the other bearing Since the bearing retainer 4b and the engagement retainer retainer 4a are integrated, it becomes impossible to assemble in the same assembly line in the bearing assembly process. For this reason, a dummy bearing retainer is incorporated in the other bearing, and assembly, grease filling, inspection, etc. are performed on the same assembly line, and this dummy bearing retainer is removed when the one-way clutch is assembled. Thus, it is necessary to reassemble the original cage (bearing cage / engager cage integrated). Such rearrangement work is complicated, and it is desired to facilitate the work.

  Accordingly, an object of the present invention is to facilitate assembly of a one-way clutch in which an engagement cage and a bearing cage rotate together.

In order to solve the above-described problems, the present invention makes it possible to connect the separately formed engagement cage and the bearing cage 4b, and the engagement cage and the bearing cage rotate integrally by the connection. It adopts the configuration to do.
Since the structure that connects the retainer cage and the bearing cage formed separately is adopted, the left and right bearings can be made the same bearing, and work such as inserting a dummy cage during bearing assembly It becomes unnecessary. In addition, an engagement cage can be connected and incorporated in the axial direction of the bearing cage. For this reason, the attachment and detachment of the dummy cage during clutch assembly can be omitted, and the assembly of the one-way clutch can be facilitated.

  A specific configuration includes an outer ring and an inner ring that are coaxially arranged, and a plurality of rolling elements that are arranged along the circumferential direction between the outer ring and the inner ring and that support the outer ring and the inner ring so as to be relatively rotatable about an axis. When the outer ring and the inner ring relatively rotate in one direction, the outer ring and the inner ring engage with the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring to connect the two wheels, and the relative rotation in the other direction releases the engagement. A plurality of engagement elements, an engagement element holder that holds the engagement elements in the circumferential direction, and a bearing holder that holds the rolling elements of the bearing portion in the circumferential direction. In the one-way clutch that rotates together with the bearing cage, the engagement cage and the bearing cage are formed separately, and the bearing cage can be connected to the engagement cage, By the connection, the engagement cage and the bearing cage are integrated. It is configured to rotate.

As means for enabling connection of the bearing cage to the engagement cage, a well-known method such as connection by a screw member, connection by a hook, connection by caulking, welding, adhesion by an adhesive, etc. can be adopted. The bearing retainer is connected to the engagement retainer by providing a protrusion on one of the engagement cage or the bearing retainer, and providing a recess in which the projection fits on the other, and fitting the projection in the recess. A configuration can be employed.
In this way, the engagement holder and the bearing holder can be connected by fitting the protrusions and the recesses together so that the connection work and the positioning work are easy.

In addition, as the structure of the protrusion and the recess, if the protrusion is fitted into the recess so that the both are inserted and fixed or press-fitted and fixed, the engagement cage and the bearing cage can be reduced without increasing the number of parts. Can be firmly fixed.
Further, in the engaged state, a means for preventing the protrusion from coming out of the concave portion, for example, a stepped portion that increases in diameter as it approaches the inner portion is formed in the concave portion, and the protrusion is provided in the concave portion by a predetermined amount. When a mode is adopted in which a part of the protrusion is expanded in diameter by an elastic force or the like and is engaged with the stepped portion to prevent the projection from being pulled out. There is also an effect that it can be prevented from falling off the vessel.

  In the present invention, the engaging cage holder and the bearing cage, which are formed separately, can be connected to each other, and the connection between the engaging cage holder and the bearing cage is adopted. In the one-way clutch in which the cage and the bearing cage rotate together, the assembly can be facilitated.

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a pulley with a built-in clutch in which a one-way clutch is incorporated in a pulley 7.
The one-way clutch includes an outer ring 1 that is press-fitted into an inner diameter surface of a pulley 7, an inner ring 2 that is coaxially incorporated inside the outer ring 1, and a sprag (engagement element) that is incorporated between the inner and outer wheels 1 and 2. 3, an engagement element holder 4 a that holds the sprag 3, and an elastic member 6 (see FIG. 3) that urges the sprag 3 in the engagement direction.

As shown in FIG. 2, an outer peripheral cylindrical surface (outer peripheral surface) 2 a that is radially opposed to the inner peripheral cylindrical surface (inner peripheral surface) 1 a of the outer ring 1 is formed on the outer periphery of the inner ring 2.
Further, on the outer periphery of the inner ring 2, bearing fitting surfaces 2b and 2b having a slightly smaller diameter than the outer peripheral cylindrical surface 2a are formed on both sides in the axial direction of the outer peripheral cylindrical surface 2a. Bearing fitting surfaces 1b, 1b having a slightly larger diameter than the inner circumferential cylindrical surface 1a are formed on both sides in the axial direction of the inner circumferential cylindrical surface 1a, and a bearing portion 5 is formed between the bearing fitting surfaces 1b, 2b. Is supported.

  The bearing part 5 consists of a ball bearing with a single seal. The bearing portion 5 is disposed coaxially and oppositely on the outer peripheral side of the bearing inner ring 5c, and the ring-shaped bearing inner ring 5c is fitted and fixed to the bearing fitting surface 2b of the inner ring 2. And a ring-shaped bearing outer ring 5b that is fitted and fixed to the bearing fitting surface 1b. On the outer peripheral surface of the bearing inner ring 5c and the inner peripheral surface of the bearing outer ring 5b, there are circumferential grooves 5d each having a circular arc cross section for guiding a plurality of steel balls (rolling elements) 5a, 5a,. It is formed over. Further, between the bearing inner ring 5c and the bearing outer ring 5b, a ring-shaped bearing cage 4b made of a synthetic resin molded product is coaxially arranged, and a plurality of pockets 4d provided in the bearing cage 4b. The steel balls 5a, 5a,... Are held so as to be able to roll at regular intervals at predetermined intervals in the circumferential direction.

In addition, grease is sealed in a space between the outer ring 1 and the inner ring 2 between the bearing portions 5 and 5 provided on both sides in the axial direction, and seals 5e for closing the space are respectively provided on the shafts of the bearing portions 5 and 5. It is assembled so as to be located outside in the direction.
Thus, the outer ring 1 and the inner ring 2 integral with the pulley 7 are relatively rotatable about the axis by the pair of bearing inner and outer rings 5c and 5b and the steel ball 5a.

Each sprag 3 is arranged between the inner peripheral cylindrical surface 1a of the outer ring 1 and the outer peripheral cylindrical surface 2a of the inner ring 2 at a predetermined interval in the circumferential direction, and is arranged in a ring shape coaxially. It is positioned in the circumferential direction by the engagement holder 4a.
The engaging cage 4a is made of a synthetic resin molded product, and has a plurality of pockets 4c for individually accommodating the sprags 3 and a space for accommodating the elastic member 6. The accommodated elastic member 6 biases the sprags 3 in directions in which cam surfaces formed on the sprags 3 engage with the inner peripheral cylindrical surface 1 a of the outer ring 1 and the outer peripheral cylindrical surface 2 a of the inner ring 2.

  As shown in FIGS. 1A and 1B, the engagement cage 4a and the bearing cage 4b are provided on the end surface of the bearing cage 4b in the recess 12 provided on the end surface of the engagement cage 4a. The protrusion 11 is fitted and inserted. Since the engagement holder 4a and the bearing holder 4b are connected, the connection allows the engagement holder 4a and the bearing holder 4b to rotate integrally.

Here, in this pulley with a built-in clutch, the outer ring 1 provided with the pulley 7 is the driving side and the inner ring 2 is the driven side, and the outer ring 1 together with the pulley 7 is relative to the inner ring 2 in the direction of the arrow f2 shown in FIG. When rotated, each sprag 3 changes its posture in the direction indicated by arrow s1 in the figure, and each cam surface of the sprag 3 changes to the inner peripheral cylindrical surface 1a of the outer ring 1 and the outer peripheral cylindrical surface 2a of the inner ring 2. Engage. By this engagement, the rotation of the pulley 7 is transmitted to the inner ring 2.
Further, each sprag 3 rotates relative to the inner ring 2 in which the outer ring 1 rotates relative to the inner ring 2 in the direction indicated by the arrow f1, or rotates in the same direction relative to the outer ring 1 rotating in the direction of the arrow f2. When the speed exceeds the rotational speed of the outer ring 1, the sprag 3 changes its posture in the direction indicated by the arrow s2 in the figure, and the sprag 3 is disengaged from the inner and outer cylindrical surfaces 1a, 2a. The rotation transmission from the inner ring 2 to the inner ring 2 is interrupted.

For this reason, if such a pulley with a built-in clutch is attached to the rotating shaft of the alternator and the alternator is driven by driving a belt between the pulley attached to the crankshaft and the pulley on the rotating shaft, the angular speed of the crankshaft increases. At this time, the one-way clutch 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 is idling, 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 7 and the belt applied thereto, and to suppress wear of the belt.

  In the operation of this one-way clutch, as described above, the engagement holder 4a and the bearing holder 4b on the right side in the figure rotate integrally, so that when the inner and outer rings 2, 1 are idle, The sprags 3 are slid to reduce the sliding speed of the sprags 3 with respect to the inner ring 2, and the cam surface on the side contacting the inner ring 2 among the cam surfaces of the engagement elements 3 is excessively worn. It is preventing.

  The one-way clutch assembling method will be described. All sprags 3 are mounted in the respective pockets 4c of the engagement holder 4a to which the elastic member 6 is previously mounted. At this time, the sprag 3 attached to the engagement holder 4a may be configured to be prevented from falling off by the elastic member 6.

An engagement element holder 4a fitted with the elastic member 6 and the sprag 3 is assembled inside the inner peripheral surface 1a of the outer ring 1 press-fitted into the pulley 7 so that the inner ring 2 is positioned inside the engagement element holder 4a.
At this time, the bearing portion 5 on the left side shown in FIG. 1, that is, the bearing portion 5 on the side where the bearing cage 4 b that is not integrated with the engaging cage cage 4 a is incorporated is the bearing inner and outer rings 5 c and 5 b that are constituent members. The ball 5 a and the bearing cage 4 b are all assembled between the inner and outer rings 2 and 1.
In this state, it is possible to inspect the operating state such as the engagement state and the engagement release of the sprag 3 to the outer ring 1 and the inner ring 2.

When the inspection is completed, the right bearing portion 5 shown in FIG. 1, that is, the bearing portion 5 on the side where the bearing retainer 4b integrated with the engagement retainer 4a is assembled is incorporated.
The bearing inner and outer rings 5c and 5b, the steel balls 5a, and the bearing cage 4b, which are constituent members of the bearing section 5, are assembled in advance in a ring shape, and the bearing section 5 is press-fitted between the inner and outer rings 2 and 1.

At this time, the protrusion 11 provided on the end surface of the bearing retainer 4b is fitted and fixed in the recess 12 provided on the end surface of the engagement retainer 4a. Moreover, the latching | locking part 11a provided in the protrusion 11 engages with the step part 12a provided in the recessed part 12, and is prevented from coming off (refer FIG.1 (c)). For this reason, the engagement holder 4a and the bearing holder 4b on the right side in the drawing are connected to each other and can rotate integrally around the axis of the one-way clutch.
In addition, when employ | adopting a retaining structure, it is not limited to the structure by the said latching | locking part 11a and the step part 12a, The other well-known retaining structure can also be employ | adopted.

  Finally, grease is sealed in a space between the inner peripheral surface 1a of the outer ring 1 and the outer peripheral surface 2a of the inner ring 2, and a predetermined seal 5e is assembled in the bearing portions 5 on both axial sides.

  The protrusions 11 and the recesses 12 only need to be provided at least one place along the circumferential direction of the two cages 4a and 4b. If the number of places is increased, the connection between the two can be strengthened. .

In addition, when the bearing portion 5 on the right side shown in FIG. 1A, that is, the bearing portion 5 on the side where the bearing retainer 4b integrated with the engagement retainer 4a is incorporated, the bearing retainer 4b is preliminarily incorporated. The inner and outer rings 5c and 5b and the steel balls 5a except the bearings are assembled in an annular shape and press-fitted between the inner and outer rings 2 and 1, and then the steel balls 5a are equally divided in the circumferential direction, and then the inner side from the outside in the axial direction. The bearing cage 4b may be incorporated so as to be pushed toward the side.
When the pocket 4d of the bearing retainer 4b is formed in a concave shape that opens to the axial end surface of the bearing retainer 4b, in the state where all the steel balls 5a are incorporated between the bearing inner and outer rings 5c, 5b, If the steel balls 5a are equally divided in the circumferential direction, the bearing cage 4b can be pushed so that the steel balls 5a fit into the respective pockets 4d, so that such an assembling procedure can be adopted.

In this embodiment, the bearing retainer 4b on the left side in the drawing is not connected to the engagement retainer 4a (see the lower left part shown in FIG. 1A), but the shaft of the engagement retainer 4a Concave portions 12 may be provided on both sides in the direction, and bearing cages 4b and 4b may be connected to the both sides in the axial direction of the engagement cage 4a.
Further, in FIG. 1A, the same bearing retainer 4b on the side not connected to the engagement retainer retainer 4a shown on the left side in the drawing can be used. For this reason, there is an advantage that the types of parts are not increased.

In this embodiment, the engaging cage 4a is provided with the recess 12 and the bearing cage 4b is provided with the protrusion 11. However, the present invention is not limited to this embodiment, and the engaging cage 4a is provided with the projection 11 and the bearing cage 4b. A configuration in which a recess 12 is provided on the surface can also be employed (see FIG. 4). The point that the bearing holder 4b is connected to the engagement holder 4a by fitting the protrusion 11 into the recess 12 is the same.
Moreover, in the said embodiment, although the ball bearing with a single seal was employ | adopted as the bearing part 5, it is provided with the some rolling element 5a, and the bearing structure which consists of the structure which hold | maintains the rolling element 5a in the circumferential direction with the bearing holder 4b. Can be adopted. For example, a roller bearing or the like can be employed.

  The above embodiment is a pulley with a built-in clutch incorporating a one-way clutch. The outer ring 1 is a driving side and the inner ring 2 is a driven side. However, as another embodiment, the inner ring 2 is a driving side and the outer ring 1 is driven. It can also be applied to one-way clutches for various uses.

1 shows an embodiment, (a) is a cut front view, (b) is an enlarged view of the main part of (a), (c) is an enlarged view of the main part of (b). Sectional side view in the II cross section of FIG. (A) The cut-away side view in the II-II cross section of FIG. 1, (b) The principal part enlarged view of (a). The principal part enlarged view of other embodiment Cutting front view of conventional example

Explanation of symbols

1 Outer ring 2 Inner ring 3 Sprag (engagement element)
4a Engagement cage 4b Bearing cage 4c, 4d Pocket 5 Bearing portion 5a Rolling element (steel ball)
5b Bearing outer ring 5c Bearing inner ring 5d Circumferential groove 6 Elastic member 7 Pulley 11 Protrusion 11a Locking part 12 Recessed part 12a Step part

Claims (2)

A plurality of rolling elements which are arranged along the circumferential direction between the outer ring 1 and the inner ring 2 arranged on the same axis and between the outer ring 1 and the inner ring 2 and support the outer ring 1 and the inner ring 2 so as to be relatively rotatable around an axis. When the bearing portion 5 having 5a and the outer ring 1 and the inner ring 2 are relatively rotated in one direction, they are engaged with the inner peripheral surface 1a of the outer ring 1 and the outer peripheral surface 2a of the inner ring 2 to couple the two wheels 1 and 2 together. A plurality of engagement elements 3 that are disengaged when rotated in the other direction, engagement element holders 4a that hold the engagement elements 3 in the circumferential direction, and rolling elements 5a of the bearing portion 5 in the circumferential direction. A one-way clutch comprising a bearing holder 4b for holding, and rotating the engagement holder 4a and the bearing holder 4b integrally;
The engagement retainer 4a and the bearing retainer 4b are formed separately, and the bearing retainer 4b can be connected to the engagement retainer retainer 4a. By the connection, the engagement retainer retainer 4a and the bearing retainer can be connected. The one-way clutch characterized by rotating together with 4b.   A projection 11 is provided on one of the engagement cage 4a or the bearing cage 4b, a recess 12 in which the projection is fitted is provided on the other side, and the projection 11 is fitted in the recess 12 so that the engagement cage 4a The one-way clutch according to claim 1, wherein the bearing cage 4 b is connected.

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