JP2011089613A - Turning energizing device and pulley device equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a turning energizing device capable of effectively relieving the rotating speed variation of an outside member such as a pulley member and an inside member such as a pulley boss and suitably nullifying an axial force generated with the axial relative movement of an outside raceway surface and an inside raceway surface even if balls arranged at respective turning energizing mechanisms move in a circumferential direction. <P>SOLUTION: The turning energizing device K includes a pair of turning energizing mechanisms 1 juxtaposed in a first axis X1 direction. The outside raceway surface 21 and inside raceway surface 31 of each turning energizing mechanism 1 are formed around inclined second and third axes X2, X3 with respect to the first axis X1. In each turning energizing mechanism 1, the respective second and third axes X2, X3 are arranged inclining substantially at the same angle θ reversely to each other with respect to the first axis X1. Each cage 5 for holding each ball 4 of one turning energizing mechanism 1, and each cage 5 for holding each ball 4 of the other turning energizing mechanism 1, are integrally formed to integrally move the balls 4 of both turning energizing mechanisms in the circumferential direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rotation urging device having spring elasticity in a rotation direction, and a pulley device including the rotation urging device.

  An alternator used as an auxiliary machine for an engine of an automobile or the like is driven by a rotational force extracted from a crankshaft and supplies electric power necessary for running the automobile. An alternator pulley device is attached to the input shaft of the alternator, and a belt is passed between the alternator pulley device and a pulley attached to the crankshaft to transmit the engine torque to the alternator. Yes.

  In general, a crankshaft of an engine such as an automobile is given a rotational force by an explosive force in a cylinder, so that the rotational speed varies. On the other hand, an alternator has a relatively heavy armature or the like rotating integrally with the input shaft inside the alternator. Therefore, if the crankshaft rotational speed fluctuates rapidly, the armature is caused by the inertial force generated by its own rotation. There may be a case where the rotational speed difference of the crankshaft cannot be followed and a rotational speed difference is temporarily generated between the crankshaft and the alternator. Such a difference in rotational speed causes slippage between the alternator pulley device and the belt and an excessive load on the belt, causing abnormal noise of the belt and shortening the service life. Further, if the initial tension of the belt is set to be relatively high in order to prevent the belt from slipping, there arises a problem that the rotational resistance of the crankshaft increases and the fuel efficiency performance of the engine is lowered.

  Under such circumstances, the conventional pulley device for an alternator includes a pulley member around which a belt is wound and a pulley boss fixed to the input shaft of the alternator in order to allow fluctuations in the rotational speed transmitted from the crankshaft. A rotating biasing mechanism was provided between them.

  Conventionally, as a rotation urging mechanism, a torsion coil spring is provided between a pulley member and a pulley boss, and the pulley member and the pulley boss are temporarily elastic in the circumferential direction by an elastic force generated by twisting the torsion coil spring. There is known a technique in which fluctuations in the rotational speed are alleviated by relative rotation to (see Patent Document 1).

Japanese Patent Laid-Open No. 5-180287

  In a conventional rotational biasing mechanism using a torsion coil spring, the relaxation characteristics of the rotational fluctuation of the pulley member relative to the pulley boss depend on the spring characteristics determined by the spring dimensions (wire diameter, free length, number of turns, etc.). It was. However, since the dimensions and the like of the torsion coil spring are limited by the installation space and the like in the alternator pulley device, it is difficult to freely set the spring characteristics. Further, since the spring constant of the torsion coil spring is constant, the spring constant cannot be freely changed according to the torsion angle. For this reason, the degree of freedom in setting the rotational fluctuation mitigation characteristics as the alternator pulley device is limited, and fluctuations in the rotational speed of the crankshaft may not be sufficiently mitigated. Moreover, there existed a problem that the intensity | strength as a pulley apparatus fell by providing a coil spring, and it became disadvantageous in terms of durability.

  Therefore, in order to solve the above problem, the applicant of the present application is configured without using a torsion coil spring, and a rotation urging mechanism (pulley) capable of increasing the degree of freedom of the rotational fluctuation relaxation characteristic of the pulley member with respect to the pulley boss. Device) (Japanese Patent Application No. 2009-145409; hereinafter simply referred to as “prior application”).

  This prior application turning biasing mechanism is provided on the inner peripheral side of the pulley member, and is provided on the outer raceway surface formed around the axis inclined with respect to the rotational axis of the pulley member and on the outer peripheral side of the pulley boss. A plurality of inner raceways formed around an axis inclined with respect to the rotational axis of the pulley member as in the outer raceway, and a plurality of rolls disposed between the outer raceway and the inner raceway. And a holder made of a plurality of spacers provided between the balls and separated from each other to hold the intervals between the balls in a variable manner. In this rotational biasing mechanism, when the pulley member rotates around the rotational axis of the pulley member relative to the pulley boss, the outer raceway surface not only moves in the circumferential direction relative to the inner raceway surface but also moves axially. The ball is gradually clamped between the outer raceway surface and the inner raceway surface in the axial direction, and as a reaction, the phase difference caused by the relative rotation between the outer raceway surface and the inner raceway surface is eliminated. The elastic force (rotating biasing force) is generated. Then, when the relative rotation angle between the outer raceway surface and the inner raceway surface reaches a predetermined value, the relative rotation between the outer raceway surface and the inner raceway surface is regulated by the balls, so that the outer member and the inner member rotate integrally. It is configured.

  In addition, the rotation urging mechanism of the prior application includes a pair of rotation urging mechanisms, and includes a rotation axis of one rotation urging mechanism and a rotation axis of the other rotation urging mechanism. It is comprised so that it may incline in the mutually opposite direction with respect to the rotating shaft center of a pulley member. Therefore, in each rotation biasing mechanism, the axial force generated by the relative movement in the axial direction between the outer raceway surface and the inner raceway surface acts so as to cancel each other, so that the pulley boss, the input shaft of the alternator, etc. An unnecessary load in the axial direction is prevented from acting.

  However, since each ball arranged between the outer raceway surface and the inner raceway surface is held by a cage made of spacers separated from each other, the circumferential movement amount (revolution) associated with the relative rotation of both raceway surfaces. Angle) are different from each other. For this reason, the space | interval of the circumferential direction of each ball | bowl changes with the relative rotation of both track surfaces. Since the change in the interval occurs for each rotation urging mechanism, the change in the interval in each rotation urging mechanism may shift from each other. In this case, the balance between the axial forces generated in the rotation biasing mechanisms that are opposite to each other is lost, so that the forces in the axial directions cannot be effectively canceled each other, and the pulley boss and the input shaft For example, an unnecessary load may be applied in the axial direction.

  The present invention has been made in view of the above circumstances, and can effectively mitigate fluctuations in rotational speed between the outer member and the inner member without using a torsion coil spring. In addition, the axial force generated by the relative movement in the axial direction between the outer raceway surface and the inner raceway surface is preferably canceled even if the balls arranged in the respective rotation urging mechanisms move in the circumferential direction. It is an object of the present invention to provide a rotation urging device that can be used, and a pulley device including the same.

  (1) The rotation urging device of the present invention has a pair of rotation urging mechanisms arranged side by side in the first axial direction, and each of the rotation urging mechanisms is rotatable about the first axis. And an outer member having an annular outer raceway surface on the inner periphery, and rotatable around the first axis, and opposed to the radially inner side of the outer raceway over the entire circumference. The inner member having an annular inner raceway surface on the outer periphery, a plurality of balls arranged to roll between the outer raceway surface and the inner raceway surface, and the interval between the plurality of balls can be changed. A plurality of spacers provided between the balls and separated from each other, the outer raceway surface being inclined with respect to the first axis. Formed around an axis, and the inner raceway surface is formed around a third axis inclined with respect to the first axis, Of the pair of rotation urging mechanisms, the second and third axes of one rotation urging mechanism and the second and third axes of the other rotation urging mechanism are the first and second rotation urging mechanisms. The cages of the one rotation urging mechanism and the cage of the other rotation urging mechanism are arranged in a direction opposite to each other and inclined at substantially the same angle. It is characterized in that the balls of the rotation urging mechanism are integrated in a state where they can move together.

  According to the present invention, the outer raceway surface and the inner raceway surface are formed around the second and third axis centers inclined with respect to the first axis. When rotating around one axis, the outer raceway moves relative to the inner raceway in the circumferential direction as well as in the axial direction. Then, due to the relative movement in the axial direction, the arrangement space of the balls between the outer raceway surface and the inner raceway surface is gradually narrowed in the axial direction. On the other hand, the plurality of balls are gradually and strongly clamped in the axial direction between the outer raceway surface and the inner raceway surface in the arrangement space that is gradually narrowed while rolling as the outer member rotates. By this action, an elastic force (rotating biasing force) is generated in a direction that eliminates a phase difference caused by relative rotation between the outer member and the inner member. When the relative rotation angle between the outer member and the inner member reaches a predetermined value, the circumferential movement and the axial relative movement between the outer race surface and the inner race surface are restricted by the balls, and the outer member and the inner member are integrated. Rotate to.

Therefore, in the present invention, it is possible to elastically absorb (relax) the rotational fluctuation between the outer member and the inner member within a range in which the outer member and the inner member can be relatively rotated. The rotational fluctuation mitigation characteristics can be freely set by changing the curvature radius of the outer raceway surface and the inner raceway surface, the diameter of the ball, etc., and the rotational fluctuation can be effectively mitigated.
Further, unlike the prior art, it is not necessary to have a complicated structure for providing a torsion coil spring or a torsion coil spring, and it is possible to form a rotation urging mechanism with a very simple structure. The mechanism can also be reduced in size. In addition, the outer member and the inner member can be formed with the outer raceway surface and the inner raceway surface around the second and third axes by substantially the same method as the processing of the raceway surface of a general rolling bearing. It is easy to manufacture. In addition, the rotation urging mechanism of the present invention has a form like a rolling bearing by the outer member, the inner member, and the balls, and can have a structure capable of supporting a radial load acting on the outer member and the inner member.

When the outer member rotates relative to the inner member, the outer raceway surface and the inner raceway surface move relative to each other not only in the circumferential direction but also in the axial direction as described above. There is a possibility that an unnecessary load is applied in the axial direction to the pulley boss, the input shaft and the like fixed to the inner member. For this reason, in this invention, while providing a pair of rotation urging mechanism, the 2nd, 3rd axis of one rotation urging mechanism and the 2nd, 3rd axis of the other rotation urging mechanism Are inclined at substantially the same angle in opposite directions with respect to the first axis, thereby making it possible to cancel the axial forces generated in the respective rotation urging mechanisms.
Moreover, in the present invention, since the holder of one rotation urging mechanism and the holder of the other rotation urging mechanism are integrated, each ball in one rotation urging mechanism and the other The balls in the rotation urging mechanism can be integrally moved in the circumferential direction by an integrated cage. Thereby, even if each ball | bowl of each rotation biasing mechanism moves to the circumferential direction and the space | interval of each ball | bowl changes, the phase of the ball | bowl in both rotation biasing mechanisms can be made to correspond substantially. For this reason, the axial forces generated in the respective rotation biasing mechanisms in the opposite directions can be made substantially equal, so that the axial forces of the respective rotation biasing mechanisms can be preferably canceled out. Therefore, an unnecessary load is not applied to the pulley boss, the input shaft and the like in the axial direction.

(2) In each of the rotation urging mechanisms, it is preferable that an inclination angle of the second axis with respect to the first axis and an inclination angle of the third axis are substantially the same. With such a configuration, processing of the outer raceway surface with respect to the outer member and processing of the inner raceway surface with respect to the inner member can be performed in substantially the same manner, and workability can be improved.
(3) In each rotation biasing mechanism, it is preferable that a plurality of the cages are provided between the balls, and the cages are separated from each other. With this configuration, the distance between the balls can be changed between the outer raceway surface and the inner raceway surface with a simple configuration, and each ball can be moved individually and smoothly in the axial direction. . Therefore, the axial force generated by each rotation urging mechanism can be canceled more suitably.

(4) A pulley apparatus according to the present invention includes a pulley member around which a belt is wound, an pulley boss disposed concentrically with the pulley member on an inner peripheral side of the pulley member, and the pulley member and the pulley boss. And a pair of rotation urging mechanisms arranged in parallel in the axial direction of the pulley member, each rotation urging mechanism having an annular shape provided on the inner peripheral side of the pulley member An outer raceway surface, an annular inner raceway surface disposed on the outer circumference side of the pulley boss on the radially inner side of the outer raceway surface so as to face the entire circumference, and between the outer raceway surface and the inner raceway surface A plurality of balls arranged so as to be capable of rolling, and a cage comprising a plurality of spacers that are provided between the balls and are separated from each other so as to hold the interval between the plurality of balls variably. And the outer raceway surface is The inner raceway surface is formed around a third axis that is inclined with respect to the first axis, and is formed around the second axis that is inclined with respect to the first axis. Of the mechanisms, the second and third axial centers of one rotational biasing mechanism and the second and third axial centers of the other rotational biasing mechanism are mutually relative to the first axial center. The retainer of the one rotation urging mechanism and the retainer of the other rotation urging mechanism are arranged in a reverse direction and inclined at substantially the same angle. It is characterized by being integrated in a state where balls can be moved together.
With such a configuration, it is possible to achieve the same function and effect as the above-described rotation urging device (1).

  According to the present invention, it is possible to effectively mitigate fluctuations in rotational speed between the outer member and the inner member without using a torsion coil spring, and the shaft between the outer raceway surface and the inner raceway surface can be reduced. The axial force generated with the relative movement of the direction can be canceled by the pair of rotation urging mechanisms even if the balls arranged in each rotation urging mechanism move in the circumferential direction.

It is sectional drawing of the pulley apparatus which concerns on embodiment of this invention. It is sectional drawing of the rotation urging | biasing mechanism in the rotation urging | biasing apparatus with which the pulley apparatus was equipped. It is a schematic front view for demonstrating the effect | action of a rotation urging | biasing mechanism. It is a schematic plan view for demonstrating the effect | action of a rotation urging | biasing mechanism. (A) is AA arrow sectional drawing of FIG. 2, (b) is B arrow schematic of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view of a pulley apparatus according to an embodiment of the present invention. The pulley device P is used by being attached to an input shaft 8 of an alternator used as an engine auxiliary machine for an automobile or the like, for example. The pulley device P includes a pulley boss 71 formed in a cylindrical shape, a cylindrical pulley member 72 disposed coaxially on the outer peripheral side of the pulley boss 71, and a rotation urging device K interposed therebetween. It has.

A wave-like groove is formed on the outer peripheral surface 72A of the pulley member 72, and the belt 9 for transmitting the rotational force from the crankshaft of the engine is wound around the outer peripheral surface 72A.
An input shaft 8 protruding from an alternator (not shown) is inserted into the inner periphery of the pulley boss 71. Further, an internal thread portion 71A is integrally formed in the axially intermediate portion of the pulley boss 71, and the external thread portion 8A provided at the end of the input shaft 8 is screwed into the internal thread portion 71A. Thus, the pulley boss 71 is connected to the input shaft 8 so as to be rotatable together. Further, a regular hexagonal wrench insertion portion 71 </ b> B for inserting a hexagon wrench for screwing the pulley boss 71 to the input shaft 8 is formed at the inner peripheral end of the pulley boss 71.

The rotation urging device K includes a pair of rotation urging mechanisms 1 arranged in parallel in the direction of a first axis X1 described later. Each rotation urging mechanism 1 is configured such that second and third axial centers X21, X31, X22, and X32, which will be described later, are inclined at substantially the same inclination angle θ in opposite directions with respect to the first axial center X1. Is arranged. Here, “substantially identical” means within a range of ± 1 degree with respect to complete identity.
FIG. 2 is a cross-sectional view of one rotation urging mechanism 1. The rotation urging mechanism 1 includes an annular outer ring (outer member) 2 having an outer raceway surface 21 on the inner periphery, an annular inner ring (inner member) 3 having an inner raceway surface 31 on the outer periphery, and an outer raceway surface 21. And a plurality of balls 4 arranged between the inner raceway surfaces 31 and a plurality of cages 5 that hold the intervals between the balls 4. In the following description, “axial direction” refers to a direction parallel to the axial center (first axial center) X1 of the outer ring 2 and the inner ring 3, and “circumferential direction” refers to the axial center X1 of the outer ring 2 and the inner ring 3. The direction around.

  The outer ring 2, the inner ring 3, and the ball 4 are made of metal such as bearing steel. Further, the outer ring 2 and the inner ring 3 are configured to be rotatable around the first axis X1. The outer raceway surface 21 and the inner raceway surface 31 have a cross-sectional shape cut along a plane passing through the first axis X1 formed in a concave arc shape (concave curved surface shape), and have a radius of curvature larger than the radius of the ball 4. Is set. The plurality of balls 4 are arranged over the entire circumference between the outer raceway surface 21 and the inner raceway surface 31 in a state of being spaced apart from each other in the circumferential direction.

  The outer raceway surface 21 is formed around the second axis X2 inclined with respect to the first axis X1. In other words, the outer raceway surface 21 is formed in parallel with the surface Y2 inclined with respect to the vertical surface Y1 orthogonal to the first axis X1. The inner raceway surface 31 is formed around a third axis X3 that is inclined with respect to the first axis X1. In other words, the inner raceway surface 31 is formed in parallel with the surface Y3 inclined with respect to the vertical surface Y1 orthogonal to the first axis X1. In the present embodiment, the second axis X2 and the third axis X3 are inclined at substantially the same inclination angle θ with respect to the first axis X1. Here, “substantially identical” means within a range of ± 1 degree with respect to complete identity.

  In the state shown in FIG. 2, the second axis X2 of the outer raceway surface 21 and the third axis X3 of the inner raceway surface 31 coincide with each other. Therefore, the outer raceway surface 21 and the inner raceway surface 31 are arranged substantially in parallel and face each other over the entire circumference in the circumferential direction. Hereinafter, this state is referred to as a reference state. For example, when the inner ring 3 is stopped and the outer ring 2 is rotated about the first axis X1, the outer raceway surface 21 moves in the circumferential direction and the axial direction with respect to the inner raceway surface 31. Hereinafter, the operation at this time will be described in detail with reference to FIGS.

  3 is a schematic front view for explaining the operation of the rotation urging mechanism 1, and FIG. 4 is a schematic plan view for explaining the operation of the rotation urging mechanism 1 (the outer track of FIG. 2). The figure which looked at the surface 21 and the inner track surface 31 in the arrow D direction). 3A and 4A, the outer raceway surface 21 and the inner raceway surface 31 are in a reference state. Then, as shown in FIGS. 3B and 4B, when the outer raceway surface 21 rotates in the arrow direction C relative to the inner raceway surface 31, the outer raceway surface 21 becomes a vertical plane Y1 ( Due to the inclination with respect to FIG. 2), the inner track surface 31 moves relative to the axial direction as well as the circumferential direction. By this relative movement in the axial direction, the axial width L of the storage space S of the ball 4 between the outer raceway surface 21 and the inner raceway surface 31 gradually becomes narrower, and the ball 4 rolls as indicated by the arrow Z. The outer raceway surface 31 is gradually sandwiched between the shoulder portion 32 and the outer raceway surface 21 in the vicinity of the shoulder portion 22. When the relative rotation of the outer ring 2 with respect to the inner ring 3 reaches a predetermined amount (angle), the circumferential movement and the axial movement of the outer raceway surface 21 and the inner raceway surface 31 are restricted by the balls 4 and follow the outer race 2 to follow the inner race. 3 rotates integrally.

  In the process in which the outer raceway surface 21 and the inner raceway surface 31 are relatively moved in the axial direction, the contact pressure between the balls 4 and the outer raceway surface 21 and the inner raceway surface 31 is gradually increased. And the direction (relative rotation direction) which cancels the phase difference by the relative rotation of the outer ring | wheel 2 and the inner ring | wheel 3 by the elastic deformation of the ball | bowl 4 and both the track surfaces 21 and 31 accompanying contact with the ball | bowl 4 and both track surfaces 21 and 31. Rotation biasing force (torsion spring force) in the opposite direction) is generated. Further, the spring constant of the rotation urging mechanism 1 gradually increases as the axial relative movement amount between the outer raceway surface 21 and the inner raceway surface 31 increases, and accordingly, the rotation urging force also increases. .

In the above configuration, when the outer ring 2 and the inner ring 3 can be rotated relative to each other within a predetermined range, and the outer ring 2 and the inner ring 3 are rotating together, the rotational fluctuation occurs between the two and the third part. It is possible to elastically absorb (relax) rotational fluctuations in the relative rotational range.
In addition, the rotational fluctuation mitigation characteristics include the curvature radius and groove depth of the outer raceway surface 21 and the inner raceway surface 31, the radius of the ball 4, and the inclination angles of the second and third axes X2 and X3 with respect to the first axis X1. It can be set freely by changing θ or the like. For example, if the curvature radius of the outer raceway surface 21 or the inner raceway surface 31 is increased, the relative rotation range of the outer ring 2 and the inner ring 3 is also increased, and the spring constant (spring stiffness) of the rotation urging mechanism 1 is set low. Is possible. Moreover, if the inclination angle θ of the second and third axial centers X2 and X3 with respect to the first axial center X1 is increased, the spring constant can be set high. Therefore, it is possible to effectively mitigate rotational fluctuations between the outer ring 2 and the inner ring 3 according to the rotational characteristics of the outer ring 2 and the inner ring 3.

  Further, the outer race surface 21 and the inner race surface 31 are formed on the outer ring 2 and the inner ring 3 without the need for a torsion coil spring or a complicated structure for providing the torsion coil spring as in the prior art. The rotation urging mechanism 1 can be formed by a very simple structure in which the balls 4 are arranged between them, and the rotation urging mechanism 1 can be downsized. Further, since the outer raceway surface 21 and the inner raceway surface 31 are formed as uniform grooves in the circumferential direction around the second and third axes X2 and X3, a method for processing the raceway surface of a general rolling bearing (polishing) The outer raceway surface 21 and the inner raceway surface 31 can be formed by substantially the same method as the method (method), and manufacture (processing) is facilitated. Further, the rotation urging mechanism 1 has a form like a rolling bearing by the outer ring 2, the inner ring 3, and the balls 4, so that a radial load acting on the outer ring 2 and the inner ring 3 can be supported.

  5A is a cross-sectional view taken along line AA in FIG. 2, and FIG. 5B is a schematic view taken along arrow B in FIG. A cage 5 is provided between each ball 4. Each cage 5 is formed of a synthetic resin material or the like, and is configured by spacers provided correspondingly between the balls 4. The cages 5 are not connected to each other in the circumferential direction and are in a separated state. Each cage 5 is formed with a concave arc-shaped (concave curved surface) facing surface 51 that faces each ball 4. As shown in FIG. 5B, the radius of curvature of the facing surface 51 is formed larger than the radius of the ball 4. Since the cage 5 is separated from each other, the distance can be changed so that the adjacent balls 4 do not contact each other with a simple configuration, and the outer raceway surface 21 and the inner raceway surface 31 can be changed. The movement of each ball 4 in the axial direction along with the relative movement in the axial direction can be performed individually and smoothly.

  In FIG. 1, each cage 5 that holds each ball 4 of one rotation urging mechanism 1 and the other rotation urging mechanism 1 that is arranged symmetrically in the axial direction with respect to each one of the balls 4. The retainers 5 that hold the balls 4 are integrally formed to extend in the axial direction so that the balls 4 of the both rotation urging mechanisms 1 can move integrally in the circumferential direction. .

  In this embodiment, when the pulley member 72 is rotated by the rotational power transmitted from the crankshaft of the engine via the belt 9, the outer raceway surface 21 moves relative to the inner raceway surface 31 in the circumferential direction and in the axial direction. Also move relative. As described with reference to FIGS. 3 and 4, the ball 4 is strongly sandwiched between the vicinity of the shoulder portion of the outer raceway surface 21 and the vicinity of the shoulder portion of the inner raceway surface 31, whereby the outer raceway surface 21. And the inner raceway surface 31 are restricted, the pulley boss 71 is rotated together with the pulley member 72, and the input shaft 8 of the alternator is rotated.

  When a rotational variation occurs between the pulley member 72 and the pulley boss 71 due to a rotational variation of the crankshaft, the rotational variation can be elastically reduced by the relative rotation of the pulley member 72 and the pulley boss 71. And the slip which arises between the belt 9 and the pulley member 72 can be suppressed effectively by relieving the fluctuation | variation of the rotational speed of a crankshaft. Therefore, the initial tension of the belt 9 can be set low, the load on the crankshaft can be reduced, and the fuel efficiency performance of the engine can be improved.

  When the pulley member 72 rotates relative to the pulley boss 71, the outer raceway surface 21 and the inner raceway surface 31 move relative to each other not only in the circumferential direction but also in the axial direction, and in particular, axial force is generated by the relative movement in the axial direction. This force may act on the pulley member 72 and the pulley boss 71 (input shaft 8). However, in the present embodiment, the pair of rotation urging mechanisms 1 are arranged symmetrically in the axial direction, and the second and third axial centers X21, X31, X22, and X32 are mutually relative to the first axial center X1. Since they are inclined in the opposite direction and at substantially the same inclination angle θ, the axial forces generated in the respective rotation urging mechanisms 1 cancel each other.

  Moreover, in the present embodiment, each cage 5 of one rotation biasing mechanism 1 and each cage 5 of the other rotation biasing mechanism 1 are integrated, so that each rotation biasing mechanism 1 When the both raceway surfaces 21 and 31 rotate relative to each other, the balls 4 of one rotation urging mechanism 1 and the balls 4 of the other rotation urging mechanism 1 are integrated by an integrated cage. It can be moved integrally in the circumferential direction. Thereby, even if each ball | bowl 4 of each rotation urging mechanism 1 moves to the circumferential direction, even if the space | interval of each ball | bowl 4 changes, the phase of the ball | bowl 4 in both rotation urging mechanisms 1 can be made to correspond substantially. it can. For this reason, it is possible to make the axial forces generated in the respective rotation urging mechanisms 1 in the opposite directions substantially equal to each other. As a result, the axial force of each rotation urging mechanism 1 can be suitably canceled, and an unnecessary load in the axial direction can be prevented from being applied to the input shaft 8 or the like.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed in design. For example, in the above-described embodiment, the plurality of cages 5 arranged in the circumferential direction in each rotation biasing mechanism 1 are not connected to each other and are in a separated state, but a plurality of cages for holding a plurality of balls are used. An integrated retainer in which a pocket is formed may be provided. The material of the cage 5 is not limited to a synthetic resin, and may be a metal such as bearing steel.

  The inclination angle of the second axis X2 with respect to the first axis X1 and the inclination angle of the third axis X3 do not necessarily coincide with each other, and both the raceway surfaces 21 and 31 face each other over the entire circumference. If the arrangement space for the balls 4 can be secured between the opposing surfaces, the inclination angle can be varied.

  The radius of curvature and the groove depth of the outer raceway surface 21 and the inner raceway surface 31 may be the same or different from each other. Whether the radius of curvature and the groove depth are the same or different can be appropriately designed according to the rotational characteristics of the outer member 2 and the inner member 3. Further, the number of trajectory rows of the balls 4 is not limited to one row, and may be double rows such as 2 rows and 3 rows according to the load.

  In the pulley apparatus P shown in FIG. 1, the pulley member 72 and the pulley boss 71 may constitute the outer member 2 and the inner member 3 of the rotation urging mechanism 1, respectively. In this case, the pulley member 72 and the pulley boss 71 respectively The outer raceway surface 21 and the inner raceway surface 31 may be formed directly.

  The rotation urging device K of the present invention can be applied to, for example, a crank pulley, a pulley for a car air conditioner, an auto tensioner, and the like in addition to a pulley device for an alternator. It can also be used for a clutch disk of a clutch. Further, it can be used as a torque sensor by attaching an angle sensor that can measure the rotation angle between the inner and outer rings.

  1: rotating urging mechanism, 2: outer ring (outer member), 21: outer raceway surface, 3: inner ring (inner member), 31: inner raceway surface, 4: ball, 5: cage, 71: pulley boss, 72 : Pulley member, 9: belt, K: rotational biasing device, P: pulley device, X1: first axis, X2: second axis, X21: second axis, X22: second axis, X3 : Third axis, X31: Third axis, X32: Third axis, θ: Inclination angle

Claims (3)

A pair of rotation urging mechanisms are juxtaposed in the first axial direction,
Each of the rotation urging mechanisms is
An outer member rotatable around the first axis and having an annular outer raceway surface on the inner periphery;
An inner member that is rotatable about the first axis and has an annular inner raceway surface on the outer circumference that faces the entire inner circumference in the radial direction of the outer raceway surface;
A plurality of balls arranged to roll between the outer raceway surface and the inner raceway surface;
A cage composed of a plurality of spacers that are provided between the balls and are separated from each other in the circumferential direction to hold the intervals between the balls in a variable manner;
The outer raceway surface is formed around a second axis inclined with respect to the first axis;
The inner raceway surface is formed around a third axis inclined with respect to the first axis;
Of the pair of rotation urging mechanisms, the second and third axes of one rotation urging mechanism and the second and third axes of the other rotation urging mechanism are the first and second rotation urging mechanisms. Inclined at substantially the same angle in opposite directions with respect to one axis,
The cage of the one rotation urging mechanism and the cage of the other rotation urging mechanism are integrated so that the balls of both rotation urging mechanisms can be moved integrally in the circumferential direction. A rotation urging device characterized by that.   2. The rotation urging device according to claim 1, wherein in each of the rotation urging mechanisms, an inclination angle of the second axis with respect to the first axis and an inclination angle of the third axis are substantially the same. A pulley member around which a belt is wound;
A pulley boss arranged concentrically with the pulley member on the inner peripheral side of the pulley member,
A pair of rotational urging mechanisms disposed between the pulley member and the pulley boss and arranged in parallel in the axial direction of the pulley member,
Each of the rotation urging mechanisms is
An annular outer raceway surface provided on the inner peripheral side of the pulley member;
An annular inner raceway surface disposed on the radially outer side of the pulley boss on the radially inner side of the outer raceway so as to face the entire circumference;
A plurality of balls arranged to roll between the outer raceway surface and the inner raceway surface;
A cage composed of a plurality of spacers that are provided between the balls and are separated from each other in the circumferential direction to hold the intervals between the balls in a variable manner;
The outer raceway surface is formed around a second axis inclined with respect to the rotation axis of the pulley member;
The inner raceway surface is formed around a third axis inclined with respect to the rotation axis of the pulley member;
Of the pair of rotation urging mechanisms, the second and third axes of one rotation urging mechanism and the second and third axes of the other rotation urging mechanism are the first and second rotation urging mechanisms. Inclined at substantially the same angle in opposite directions with respect to one axis,
The cage of the one rotation urging mechanism and the cage of the other rotation urging mechanism are integrated so that the balls of both rotation urging mechanisms can be moved integrally in the circumferential direction. The pulley apparatus characterized by the above-mentioned.

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