JP2003004122A - Pulley unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of a pulley unit that it is difficult to set the pulley unit in a narrow space around an engine because a ball, a one-way clutch and a roller are assembled in this order in the bearing space between the rotor shaft and the pulley in the pulley unit, and the holder of the ball is inserted into the bearing space from outside in the axial direction to mount a pocket part on the ball, and therefore, an annular part of the holder is located as projecting outward in the axial direction and the width of the puller unit is increased by the projection. SOLUTION: The holder 17 comprises the annular part 17a and the pocket part 17b integrally formed of the annular part 17a for holding several balls, and the annular part 17a of the holder 17 is assembled to be located on the one-way clutch 6 side. Therefore, a seal member 18 can be brought close to the fixing end of the balls 7 and accordingly, the total width of the pulley unit 1 can be reduced. As a result, the pulley unit 1 can be set in a narrow space around the engine.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating shaft of an auxiliary machine (a rotating shaft for power generation of an alternator), for example, by driving a crankshaft attached to an automobile engine via a belt. Etc.) for transmitting to the pulley unit. 2. Description of the Related Art There is a conventional pulley unit as shown in FIG. The pulley unit 1 is attached to a rotary shaft for driving an accessory of an automobile engine. Examples of the accessory include an alternator 2, other compressors for an air conditioner, a water pump, a cooling fan, and the like. The illustrated pulley unit 1 is arranged at a portion connecting a driving portion of the engine and a rotating shaft 3 for power generation of an alternator 2, and a protrusion of the rotating shaft 3 for power generation protruding laterally from the alternator main body 4. A hollow shaft portion (hereinafter referred to as a “rotor shaft”) 5 which is fitted to the outer portion of the rotor shaft 5.
A pulley 10 for winding a power transmission V-ribbed belt 9 to which power from an engine is transmitted via a bearing space 11 is externally fitted. In the bearing space 11, a one-way clutch 6 and balls 7 (deep-groove ball bearings) held by a retainer 7a are arranged on both sides thereof, that is, on the alternator 2 side (fixed end side). On the opposite side (free end side) of the ball 7, a roller 8 held by a retainer 8a is disposed, and the function of the one-way clutch 6 causes the rotor shaft 5 to move only in one direction accompanying the rotation of the pulley 10. It is configured to be rotatable. Here, a retainer 7a of the ball 7 is shown in a perspective view of FIG. This is called a crown retainer (for example, made of resin), and is formed integrally with the annular portion 7b on the fixed end side and on the free end side of the annular portion 7b for accommodating the ball 7. It is formed from a plurality of pockets 7c. [0006] Generally, in the pulley unit 1, a bearing space 11 between the rotor shaft 5 and the pulley 10 is provided.
On the other hand, the ball 7, the one-way clutch 6, and the roller 8 are assembled in this order from the fixed end to the free end, and the retainer 7a of the ball 7 is inserted into the bearing space 11 from the fixed end, The balls 7 are mounted in the pockets 7c while being kept at equal circumferences. Therefore, the annular portion 7b of the holder 7a
When it is mounted on the ball 7, it is located on the fixed end side, that is, on the outer side in the axial direction of the pulley unit 1. [0007] In the case of a front-wheel drive vehicle, the space around the engine is narrowed because the engine is placed horizontally. The pulley unit 1 provided with the one-way clutch 6 is wider than the solid pulley by that much, so that the space to be mounted on the vehicle is insufficient. Therefore, an object of the present invention is to provide a pulley unit that can solve the above-mentioned problems. In order to solve the above-mentioned problems, a pulley unit according to the present invention has two inner and outer rings arranged concentrically and an annular bearing space between both rings. An interposed one-way clutch, including rolling elements disposed on both sides of the one-way clutch in the annular bearing space, the outer ring is used as a pulley around which a power transmission belt is wound, The inner ring is connected to a rotating shaft for driving auxiliary equipment, a plurality of balls are used as rolling elements on one side of the two rolling elements, and a plurality of rollers are used as rolling elements on the other side, The ball retainer is formed in a crown shape from an annular portion and a plurality of holding portions integrally formed with the annular portion, and the annular portion of the retainer is arranged on the one-way clutch side to hold the ball. It is attached to the part. [0010] As described above, the annular portion of the ball cage is disposed on the one-way clutch side and the ball is mounted on the holding portion, so that the cage does not protrude axially outward with respect to the ball. Therefore, the width of the entire pulley unit can be reduced by that much, and the pulley unit can be installed even in a narrow space. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A pulley unit 1 according to an embodiment of the present invention will be described below with reference to FIGS. A pulley unit 1 according to an embodiment of the present invention is attached to an auxiliary device of an engine. Examples of the auxiliary device include an alternator 2 for an automobile, a compressor for an air conditioner, There are pumps and cooling fans. The pulley unit 1 is disposed at a portion connecting the drive unit of the engine and the rotating shaft 3 for power generation of the alternator 2, and is externally attached to a protruding portion of the rotating shaft 3 for power generation protruding laterally from the alternator main body 4. It has a hollow shaft portion (hereinafter referred to as a “rotor shaft”) 5 to be fitted, and the one-way clutch 6 and rolling elements disposed on both sides thereof, that is, the rotor shaft 5, are arranged circumferentially equally on the alternator 2 side. A plurality of balls (deep groove ball bearings) 7 arranged and a one-way clutch 6
A belt winding portion for winding a power transmission V-ribbed belt 9 through which a power from an engine is transmitted through a plurality of rollers 8 arranged at regular intervals on the opposite side of the ball 7 across the ball 7. A pulley 10 having 10a is provided. A seal member 18 for sealing the annular bearing space 11 is mounted on both axial sides of the roller 8 and the ball 7, and these seal members 18 are covered with an annular core 19 and the outside thereof. One end of the elastic body 20 in the radial direction is fixed to the inner peripheral surface of the pulley 10, and the other end is a seal lip and is in contact with the outer peripheral surface of the rotor shaft 5. . Further, an annular body 21 for preventing muddy water and the like from entering the inside of the annular bearing space 11 is fixed to the outer peripheral surface of the free end side end of the rotor shaft 5 between the inner peripheral surface of the free end of the pulley 10 and the outer peripheral surface. ing. The one-way clutch 6 is disposed substantially at the center in the axial direction of an annular bearing space 11 in which the pulley 10 and the rotor shaft 5 are opposed to each other. This portion is formed as a cam surface 5a (an octagon in FIGS. 2 and 3).
a is formed with a tapered step portion 5b connected to the large-diameter region (the inner raceway surface of the ball 7) on the fixed end side, and the entire one-way clutch 6 moves toward the ball 7 by the tapered step portion 5b. The cam surface 5a is formed with a tapered step portion 5c connected to a small-diameter region (the inner raceway surface of the roller 8) on the free end side. A wedge-shaped space A is formed by the cam surface 5a and the circular inner peripheral surface 10a of the pulley 10. The inner raceway surface of the roller 12 as a rolling element of the one-way clutch 6 is the cam surface 5a. The outer raceway surface of the roller 12 is the inner peripheral surface 10 a of the pulley 10. The one-way clutch 6 has an annular roller retainer 13 made of synthetic resin and an elliptical coil spring 14 having a function of urging the roller 12 toward the narrow side (lock side) of the wedge-shaped space A. , This coil spring 14
Are mounted on protrusions 13b which are circumferentially projecting toward the wedge-shaped space A on the side wall surface of a column portion 13a formed in the roller retainer 13 at equal circumferential positions along the axial direction. . With such a configuration of the one-way clutch 6, the rotational speed difference between the pulley 10 and the rotor shaft 5 can
When the one-way clutch 6 enters the locked state or the free state, power is transmitted from the pulley 10 to the rotor shaft 5 or power is shut off. When the one-way clutch 6 is in the free state, the rotor shaft 5 continues to rotate by its own rotational inertia. The roller 8 has a free end side inner peripheral surface of the pulley 10 as an outer ring raceway surface, a free end side circular outer peripheral surface (small diameter region) of the rotor shaft 5 as an inner ring raceway surface, It is held in the arrangement position. The ball 7 has a fixed end side inner peripheral surface of the pulley 10 as an outer ring raceway surface, a fixed end side circular outer peripheral surface (large diameter area) of the rotor shaft 5 as an inner ring raceway surface, It is held in an evenly distributed position. FIG. 4 is a perspective view of the retainer 17 of the ball 7,
The retainer 17 has an annular portion 17a disposed on the one-way clutch 6 side (free end side), and a pocket 17b integrally formed on the annular portion 17a and serving as a ball holding portion for holding a plurality of balls. And the corner of the annular portion 17a is an inclined surface to form a reduced diameter portion 17c. A center hole 22 is formed in the rotor shaft 5, and an operation groove 23 into which a tool (for example, a hexagon wrench) for rotating the rotor shaft 5 is formed at a free end thereof. In the middle of the center hole 22, there is formed a female screw part 25 to which a male screw part 24 formed in the middle of the power generation rotary shaft 3 is screwed. In the above configuration, when assembling the pulley unit, the ball 7 is first assembled into the annular bearing space 11 between the rotor shaft 5 and the pulley 10. Next, in a state where these balls 7 are held at circumferentially equidistant positions,
Into the annular bearing space 11 from the free end side,
Each ball 7 is attached to the pocket 17b. Subsequently, the one-way clutch 6 and the rollers 8 are assembled in this order. By doing so, the annular portion 17a of the retainer 17 is located on the one-way clutch 6 side, so that the sealing member 18 can approach the fixed end side of the ball 7 and accordingly. The width of the entire pulley unit 1
It is possible to reduce the size compared with the conventional case, and therefore, it is possible to cope with a case where the installation space around the engine is narrow, such as when the engine is placed horizontally in a front wheel drive vehicle, and to effectively use this space. Can be. By arranging the annular portion 17a of the retainer 17 on the one-way clutch 6 side, the space between the balls 7 and 8 is reduced, but in the embodiment of the present invention, the annular shape of the retainer 17 is reduced. Since the cross-sectional area (volume) of the retainer 17 is reduced by forming the reduced diameter portion 17c in the portion 17a, a decrease in the volume of the space between the balls 7 and 8 can be suppressed. In the above embodiment, the inner peripheral surface of the pulley 10 is used directly as the outer raceway surface, and the outer peripheral surface of the rotor shaft 5 is used directly as the inner raceway surface. However, the present invention is not limited to this. Although not shown, although not shown, an annular member of another member is fitted to the inner peripheral surface of the pulley 10 to be integrated with the pulley 10, and the inner peripheral surface of this annular member is used as an outer ring raceway surface. In addition, an annular body of another member is fitted to the outer peripheral surface of the rotor shaft 5 to be integrated with the rotor shaft 5, and the present invention can be applied to a pulley unit of a type in which the outer peripheral surface of the annular body is used as an inner raceway surface. it can. In this case, the same operation and effect as those of the above embodiment can be obtained. As is apparent from the above description, the present invention provides a ball as a rolling element on the one-way clutch located at the center of an annular bearing space formed by two inner and outer rings. Since the annular portion of the crown-shaped retainer for holding the pulley unit is arranged, the width of the entire pulley unit can be reduced as compared with the conventional case, and therefore, for example, in the front wheel drive vehicle as in the embodiment, the engine can be moved sideways. The pulley unit can be installed even in a case where the installation space around the engine is small, such as when placing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing an overall configuration of a pulley unit according to an embodiment of the present invention. FIG. 2 is an exploded perspective view showing a rotor shaft and a retainer of a one-way clutch. FIG. 3 is a sectional view of a one-way clutch part of the pulley unit. FIG. 4 is a single perspective view of the ball retainer. FIG. 5 is a cross-sectional view showing the entire configuration of a conventional pulley unit. FIG. 6 is a single perspective view of the ball retainer. [Description of Signs] 1 Pulley unit 2 Alternator 5 Rotor shaft 6 One-way clutch 7 Ball 8 Roller 9 V-ribbed belt 10 Pulley 11 Annular bearing space 10a Belt winding portion 17 Ball retainer 17a Annular portion 17b Pocket 17c Reduced diameter portion

Continuation of front page    F-term (reference) 3J031 AC06 AC10 BA04 BA08 BA19                       CA03 CA10                 3J101 AA02 AA32 AA42 AA54 AA62                       AA72 AA77 AA83 BA25 BA44                       BA53 BA54 BA55 BA56 BA73                       BA77 FA53 GA01 GA21 GA24                       GA29

Claims (1)

Claims: 1. An inner and outer ring which is arranged concentrically,
A one-way clutch interposed in an annular bearing space between the two ring members, and rolling elements disposed on both sides of the one-way clutch in the annular bearing space, wherein the outer ring member is a belt for transmitting power. Is used as a pulley around which an inner ring is connected to a rotating shaft for driving auxiliary equipment, a plurality of balls are used as rolling elements on one side of the rolling elements, and rolling elements on the other side are used. A plurality of rollers are used as a moving body, and the ball cage is a pulley unit formed in a crown shape from an annular portion and a plurality of holding portions formed integrally with the annular portion. A pulley unit characterized in that the portion is disposed on the one-way clutch side and the ball is mounted on the holding portion.