JP3640771B2 - Pulley unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pulley unit including a one-way clutch. This pulley unit can be mounted on an auxiliary machine driven via a belt from a crankshaft of an engine such as an automobile. Examples of the auxiliary machine include a compressor for an air conditioner of a car, a water pump, an alternator, and a cooling fan.
[0002]
[Prior art]
Various auxiliary machines mounted on an automobile engine are driven via a belt by a crankshaft of the engine. Here, in the case of an alternator, in particular, in the case of an auxiliary machine, if it is connected so as to rotate synchronously with the crankshaft of the engine, when the number of rotations of the crankshaft decreases, the power generation capacity of the alternator decreases.
[0003]
Therefore, the applicant of the present application incorporates the above-described one-way clutch in the alternator, and when the rotational speed of the crankshaft decreases, the rotation of the alternator rotor is continued by its inertial force to increase the power generation efficiency. thinking.
[0004]
In this case, a one-way clutch is interposed between the pulley of the alternator and the rotor, and the one-way clutch is in a free state (power transmission state) and a locked state (power transmission cut-off state) according to the rotational difference between the pulley and the rotor. ) To transmit power between the pulley and the rotor.
[0005]
The one-way clutch described above originally needs to prevent the retainer from rotating with respect to the member on which the cam surface is formed in order to perform the lock and free operations. As a countermeasure against the rotation of the cage, the applicant of the present application considers a configuration as shown in the specification attached to the actual application No. 5-5162. That is, the concave cam surface formed at several places on the circumference of the outer ring extends to one end in the axial direction, and at one end in the axial direction of the cage, a convex portion that engages with the concave cam surface is provided at several places on the circumference of the outer circumference. The retainer is prevented from rotating with respect to the outer ring by being caught in the circumferential direction of the convex portion with respect to the concave cam surface.
[0006]
[Problems to be solved by the invention]
The conventional one-way clutch has a structure in which the existing concave cam surface formed on the outer ring is diverted to prevent the cage from rotating, and the following problems occur.
[0007]
In the first place, the cross-sectional shape of the existing concave cam surface is not a constant radius of curvature like an arc. And, in order to prevent only the retainer from rotating, it is considered wasteful in terms of cost to process the cross-sectional shape of the convex portion with high accuracy by corresponding to the concave cam surface described above. The convex portion is set to merely engage the concave cam surface. In such a structure, when the one-way clutch is locked or free, the cage is likely to wobble in the circumferential direction due to the reaction force of the elastic member for urging the rollers, and as a result, the responsiveness at the time of locking and free operation is achieved. In addition to being worse, it may happen that it is not fully locked in severe cases. Also, in situations where vibration continues to occur as the outer ring or inner ring rotates, the cage may be displaced in the axial direction, making it easier for the rollers to skew, locking and free operation It is pointed out that is likely to become unstable.
[0008]
Accordingly, an object of the present invention is to stabilize the operation of a pulley unit including a one-way clutch by making the cage of the one-way clutch immovable in the circumferential direction and the axial direction.
[0009]
[Means for Solving the Problems]
The first pulley unit of the present invention is interposed in an outer ring that is rotationally driven by a belt, an inner ring disposed on the inner periphery of the outer ring, and an annular space between both rings. A pulley unit including a one-way clutch and rolling bearings provided on both sides of the one-way clutch in the annular space, wherein the one-way clutch includes a plurality of rollers and a cage having a pocket for storing the plurality of rollers. An outer ring disposed on the outer periphery of the cage, an inner ring provided with a cam surface for forming a wedge-shaped space at a position corresponding to the pocket of the cage, and an elasticity for pressing the roller toward the narrow side of the wedge-shaped space and a member, the recess opening towards the shaft end in the axial end face of the inner ring, but also, the convex portion to be fitted in the axial direction in the axial direction end in the peripheral side in the concave portion of said retainer, Provided on the opening side of the recess. Serial is inner ring disposed on one of the rolling bearing of the rolling bearings, the convex portion is sandwiched between the inner race end surface of the one rolling bearing and the recess inner wall surface.
According to a second pulley unit of the present invention, in the first pulley unit, a sealing member is provided only at each axial end of each of the rolling bearings.
[0010]
Pulleys unit includes inner and outer two annulus disposed concentrically, and a one-way clutch interposed in an annular space between the two ring bodies, the rolling is provided on both sides of the one-way clutch in said annular space The one-way clutch includes inner and outer rings, rollers, and cages, and the end of the shaft is formed on one end surface in the axial direction on the side where the cam surface for forming the wedge-shaped space is formed. A concave portion that is open toward the concave portion, and a convex portion that is fitted into the concave portion from the axial direction is provided at one end of the cage in the axial direction, and the two rolling bearings are provided on the opening side of the concave portion. One rolling bearing may be provided, and the convex portion may be sandwiched between the inner wall surface of the concave portion and the end surface on the side where the cam surface is formed, of the inner ring and the outer ring of the one rolling bearing.
[0014]
As described above, in the pulley unit of the present invention, the one-way clutch is switched between the locked state and the free state in accordance with the rotation difference between the outer ring and the inner ring, and the power is generated between the outer ring and the inner ring. Is to transmit or block.
[0015]
And the movement of the circumferential direction of a cage | basket is sealed by fitting from the axial direction with the recessed part provided in the inner ring | wheel of the one-way clutch in which a cam surface is formed, and the convex part provided in the holder | retainer of the one-way clutch. . In addition, the movement of the cage in the axial direction is sealed by physically sealing the protruding portion from the recessed portion. Since the cage is fixed in the circumferential direction and the axial direction in this way, the cage does not wobble in the circumferential direction due to the reaction force of the elastic member for roller urging at the time of locking and free operation of the one-way clutch, The one-way clutch can be locked and freed stably, such as the roller is less likely to skew even under conditions of vibration and impact.
[0016]
In particular, in the first pulley unit of the present invention, since the cam surface of the one-way clutch is provided on the inner ring, it is possible to prevent the roller from being unnecessarily removed from the locked position by centrifugal force even in a high-speed rotation region.
[0018]
Further, in the second pulley unit, the one-way clutch is sealed by the rolling bearings on both sides in the axial direction, and the one-way clutch and the rolling bearings on both sides can be lubricated with a common lubricant. Become.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
The details of the present invention will be described based on the embodiment shown in FIGS.
[0020]
1 to 4 relate to one embodiment of the present invention, FIG. 1 is a longitudinal sectional view of a pulley unit, FIG. 2 is a sectional view taken along line (2)-(2) in FIG. 1, and FIG. FIG. 4 is a sectional view taken along line (3)-(3) in FIG. 1, and FIG. 4 is a plan development view showing a part of the one-way clutch.
[0021]
The illustrated pulley unit A includes two inner and outer rings 1 and 2 arranged concentrically, a one-way clutch 3 interposed in an annular space between both rings 1 and 2, and the annular space. Are provided with two rolling bearings 4 and 4 disposed on both sides in the axial direction of the one-way clutch 3.
[0022]
A wave-shaped belt winding groove is formed on the outer periphery of the outer ring body 1, and this outer ring body 1 is rotationally driven by a crank shaft of an automobile engine via a belt B called a so-called V-belt, for example. It has become so. The inner ring body 2 is formed of a sleeve-like member and is fixed to an input shaft (for example, a rotor of an alternator) of an auxiliary machine of an automobile, although not shown.
[0023]
The one-way clutch 3 is formed to be long in the axial direction so that the inner ring 10 provided with a flat key-like cam surface 10a at the circumference of the outer peripheral surface and the rolling bearings 4 and 4 are fitted into both ends. The outer ring 11, the retainer 12 having pockets 12a formed so as to penetrate in and out of the radial direction corresponding to the cam surface 10a, and a plurality of rollers 13 stored one by one in each pocket 12a of the retainer 12, A rectangular cross section as an elastic member that is housed in each pocket 12a of the cage 12 and that presses the rollers 13 toward the narrow side (lock side) of the wedge-shaped space between the cam surface 10a and the inner peripheral surface of the outer ring 11. Coil spring 14. The inner wall surface of the pocket 12a of the cage 12 is integrally formed with a projection 12b having a narrowed base, and one end in the axial direction of the coil spring 14 is engaged with the narrowed portion of the base of the projection 12b. By receiving the inner periphery of the coil spring 14 at the outer periphery of 12b, the coil spring 14 is prevented from being distorted during compression. In addition, the taper surface for making mounting | wearing of the coil spring 14 easy is provided in the front-end | tip outer-diameter surface of the protrusion 12b.
[0024]
Each of the two rolling bearings 4 and 4 includes a general deep groove type ball bearing having an inner ring 16, an outer ring 17, a plurality of balls 18, and a cage 19, and an axial outer end between the inner and outer rings 16 and 17. An oil seal 20 as a sealing member is attached only on the side. In other words, the one-way clutch 3 is sealed by the two rolling bearings 4 and 4, and the two rolling bearings 4 and 4 and the one-way clutch 3 are lubricated with a common lubricant.
[0025]
Next, the characteristic configuration of the pulley unit A described above will be described. This characteristic configuration is mainly that the cage 12 of the one-way clutch 3 is stationary in the circumferential direction and the axial direction. Specifically, a slit-shaped recess 10b that opens toward the shaft end and opens inward and outward in the radial direction is provided on one end surface in the axial direction of the inner ring 10 of the one-way clutch 3. Protrusions 12c that are press-fitted into the recesses 10b from the axial direction are respectively provided on the inner peripheral side, and the cage 12 moves in the circumferential direction by press-fitting between the recesses 10b and the protrusions 12c. Is sealed. Moreover, the convex part 12c is pinched | interposed from the axial direction by the back wall surface of the recessed part 10b, and the end surface of the inner ring | wheel 16 of the one rolling bearing 4 arrange | positioned at the opening side of the recessed part 10b, and, thereby, the retainer 12 The movement in the axial direction is sealed.
[0026]
In addition, the recessed part 10b and the convex part 12c are provided in two places which oppose 180 degree | times in this embodiment. This number may be at least one or more than two. However, if the number is reduced, it is advantageous in that it is not necessary to manage the processing accuracy very severely.
[0027]
Thus, since the movement in the circumferential direction and the axial direction of the cage 12 of the one-way clutch 3 is sealed, the one-way clutch 3 can be locked and freed stably. That is, if the cage 12 does not move in the circumferential direction, the reaction force of the elastic urging force of the roller 13 by the coil spring 14 can be firmly received, so that the locking operation of the roller 13 can be efficiently supported. Further, if the cage 12 does not move in the axial direction, the rollers 13 are less likely to skew even in a situation where vibration or impact is applied from the belt B or the like. For these reasons, the roller 13 can be stably locked and free.
[0028]
The operation of the pulley unit A described above will be described. In short, when the rotational speed of the outer ring 1 is relatively higher than that of the inner ring 2, the rollers 13 of the one-way clutch 3 are rolled to the narrow side of the wedge-shaped space and become locked. The body 1 and the inner ring body 2 are integrated and rotated synchronously. However, when the rotational speed of the outer ring body 1 becomes relatively slower than that of the inner ring body 2, the rollers 13 of the one-way clutch 3 are rolled to the wide side of the wedge-shaped space and become free. The transmission of rotational power from the body 1 to the inner ring body 2 is interrupted, and the inner ring body 2 continues to rotate only with the rotational inertia force.
[0029]
If such a pulley unit A is used for an alternator, the rotation of the alternator rotor is maintained at a high frequency regardless of the rotational fluctuation of the crankshaft of the engine that is the driving source of the belt B, thereby improving the power generation efficiency. Can be increased. That is, when the rotation speed of the crankshaft increases, the one-way clutch 3 is locked to rotate the inner ring body 2 synchronously with the outer ring body 1, while when the rotation speed of the crankshaft decreases, The one-way clutch 3 may be in a free state, and the inner ring 2 may be continuously rotated by its own rotational inertia force regardless of the deceleration of the outer ring 1.
[0030]
In addition, this invention is not limited only to the said Example, Various application and deformation | transformation can be considered.
[0031]
(1) In the above-described embodiment, the slit-shaped recess 10b that is continuous radially inward and outward is provided on one axial end surface of the inner ring 10 of the one-way clutch 3. However, as shown in FIG. It can be key-shaped. In FIG. 5, in order to increase the number of rollers 13 used, the circumferential width of the cam surface 10a of the inner ring 10 of the one-way clutch 3 is narrowed, and the cam surface 10a has a shape including a curve. The portion including this curve is the free rotation position of the roller 13.
[0032]
(2) In the above embodiment, the coil spring 14 is taken as an example of the elastic member of the one-way clutch 3, but various leaf springs, elastic pieces, and the like can be substituted for this.
[0033]
(3) In the above embodiment, an example is given in which the cam surface 10a of the one-way clutch 3 is formed on the inner ring side, but the present invention can also be applied to those provided on the outer ring side. However, in the case of the above embodiment, it is suitable for use at high speed rotation, such as preventing the roller from being unnecessarily removed from the locked position by centrifugal force even in the high speed rotation region.
[0034]
【The invention's effect】
In the first or second aspect of the invention, the cage of the one-way clutch is fixed in the circumferential direction and the axial direction. Therefore, the cage is held by the reaction force of the elastic member for biasing the roller during the locking and free operation of the one-way clutch. As a result, the one-way clutch can be locked and free operation can be performed stably such that the roller is less likely to skew even when vibrations or shocks are applied.
[0035]
In particular, in the invention of claim 1 , since the cam surface of the one-way clutch is provided on the inner ring, it is possible to prevent the roller from being unnecessarily removed from the locked position by centrifugal force even in the high-speed rotation region. Therefore, the synergistic effect of this effect and the effect of the movement restriction of the cage can further enhance the stabilization of the roller operation.
[0037]
Further, in the invention of claim 2 , the one-way clutch is sealed by the rolling bearings on both sides in the axial direction, and the one-way clutch and the rolling bearings on both sides can be lubricated with a common lubricant. Become.
[0038]
As described above, according to the present invention, the operation of the one-way clutch can be stabilized, and the power transmission efficiency between the two inner and outer rings arranged concentrically can be improved. it can.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a pulley unit according to an embodiment of the present invention. FIG. 2 is a sectional view taken along line (2)-(2) in FIG. FIG. 4 is a developed plan view showing a part of the one-way clutch. FIG. 5 is a diagram corresponding to FIG. 3 in another embodiment of the present invention.
A Pulley unit B Belt 1 Outer ring 2 Inner ring 3 One-way clutch 4 Rolling bearing 10 Inner ring 10a of one-way clutch Inner ring cam surface 10b Inner ring recess 11 One-way clutch outer ring 12 One-way clutch cage 12a Holding Pocket 12c Cage Convex 13 Roller 14 Coil Spring

Claims (2)

An outer ring that is rotationally driven by a belt, an inner ring disposed on the inner periphery of the outer ring, a one-way clutch interposed in an annular space between the two rings, and one in the annular space. A pulley unit including rolling bearings provided on both sides of the directional clutch,
The one-way clutch has a plurality of rollers, a cage having a pocket for accommodating the plurality of rollers, an outer ring disposed on the outer periphery of the cage, and a wedge-shaped space forming portion at a position corresponding to the pocket of the cage. Including an inner ring provided with a cam surface, and an elastic member that presses the roller toward the narrow side of the wedge-shaped space,
Recess open towards the shaft end in the axial end face of the inner ring, but also, the convex portion to be fitted in the axial direction in the axial direction end in the peripheral side in the concave portion of said retainer is provided respectively The inner ring of one of the rolling bearings is disposed on the opening side of the concave part, and the convex part is sandwiched between the inner wall of the concave part and the inner ring end surface of the one rolling bearing. Pulley unit.   2. The pulley unit according to claim 1, wherein a sealing member is provided only at each axial end of each of the rolling bearings.

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