JPH11287311A - Pulley unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent occurrence of troubles following sliding of a belt in a pulley unit having a one-way clutch by suppressing the sliding of the belt when the one-way clutch is switched to a locked state. SOLUTION: A power transmission retarding means 20 is arranged on one of outer and inner diameter sides of a one-way clutch 3, for retarding the power transmission between circular bodies 1 and 2 when the one-way clutch 3 is locked. The power transmission between a driving circular body and a driven circular body, that is, from the driving circular body (1 to 2) to the driven circular body (2 or 1) gradually performed when the one-way clutch 3 is locked. Instantaneous application of excessive rotational braking force to the driving circular body (1 or 2) is thus avoided. It is possible to suppress sliding of a belt 5 wrapped around the outer circular body 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a pulley unit with a one-way clutch. This pulley unit is
For example, it can be provided on an engine crankshaft or an auxiliary machine driven via a belt from the crankshaft. Examples of the auxiliary equipment include a compressor for an air conditioner of an automobile, a water pump, an alternator, and a cooling fan.

[0002]

2. Description of the Related Art As an example of such a conventional pulley unit, the present applicant has proposed a pulley unit as shown in FIG.

In this pulley unit B, an outer ring 31 around which a belt 36 is wound and an inner ring 32 connected to a rotating shaft of the above-mentioned auxiliary machine are arranged concentrically. In the annular space between 32, a one-way clutch 33,
Two rolling bearings 34 are provided. In operation, the one-way clutch 33 switches between the free state and the locked state in accordance with the rotational speed difference between the outer ring 31 and the inner ring 32, and the rotational power from the outer ring 31 to the inner ring 32. Block or transmit.

The one-way clutch 33 includes a plurality of rollers 37, an annular retainer 38 having pockets 39 for accommodating the rollers 37 at several locations around the circumference, and an outer ring 40 disposed on the outer periphery of the retainer 38. , An inner ring 42 disposed on the inner periphery of the retainer 38, and a spring (not shown) for urging and biasing each roller 37 toward the lock side. A cam surface (not shown) that forms a wedge-shaped space with the inner peripheral surface of the outer ring 40 is formed at several places on the outer peripheral surface of the inner ring 42 at several circumferential positions.

In the illustrated pulley unit B, a thin-walled extension 40 is provided on both axial sides of the outer race 40 of the one-way clutch 33.
a, 40b are provided, and the two rolling bearings 34, 34 are press-fitted on the inner periphery of the extended portions 40a, 40b, and the one-way clutch 33 and the two rolling bearings 34, 34 are provided.
And can be handled integrally.

[0006]

By the way, in the pulley unit B having the above structure, when the one-way clutch 33 is switched to the locked state and the two inner and outer rings 31 and 32 rotate synchronously, both the rings are rotated. Since the rotation speed difference between the bodies 31 and 32 instantaneously becomes zero, an impact is generated and the outer ring 31
The belt 36 wrapped around is slippery. That is, for example, when the outer ring 31 is driven to rotate by the belt 36, when the one-way clutch 33 is locked, the mass of the inner ring 32 is instantaneously added to the outer ring 31. Since an excessive rotation braking force acts instantaneously on the outer ring 31, the belt 36
Is slippery. The same applies to the case where the inner ring 32 is the drive side.

For example, when the pulley unit B is used as an alternator for an automobile engine, the above-mentioned phenomenon frequently occurs because the one-way clutch 33 is switched every time the engine speed changes. Belt 3
6, and the belt 36 and the outer ring 31 are likely to generate heat.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a pulley unit having a one-way clutch, which suppresses belt slippage when the one-way clutch switches to a locked state, thereby preventing adverse effects caused by belt slippage. I do.

[0009]

According to the present invention, there are provided an inner ring and an outer ring which are arranged concentrically and a rotational speed of the both rings which is interposed in an annular space between the two rings. In a pulley unit including a one-way clutch that switches between a locked state in which the one ring body and the other ring body are synchronously rotated in accordance with the difference and a free state in which the one-way clutch is relatively rotated, an outer diameter side and an inner diameter side of the one-way clutch are provided. Power transmission delay means for delaying power transmission between the two annular bodies when the one-way clutch is locked is provided on at least one of the outer diameter side and the inner diameter side of the one-way clutch. ing.

According to a second aspect of the present invention, in the first aspect, the power transmission delay means is interposed between at least one of the outer ring and the outer ring of the one-way clutch. Annular rubber material.

According to a third aspect of the present invention, in the first aspect, the inner ring has a double structure including two inner and outer rings, and the power transmission delay means includes two rings of the inner ring. An annular rubber material interposed in a state of being fixed to at least one of them.

As described above, in the present invention, the power is transmitted from the driving-side ring to the driven-side ring via the power transmission delay means in the locked state of the one-way clutch.
Therefore, when the one-way clutch is locked, the power transmission from the driving-side ring to the driven-side ring is not performed instantaneously, but is performed with a slight delay due to the presence of the power transmission delay means. In other words, even if the one-way clutch is locked, the rotational speed difference between the two ring members does not instantaneously become zero. Since the mass of the inner ring is not instantaneously applied to the ring, an excessively large rotational braking force does not act on the outer ring instantaneously. For this reason, the belt wound around the outer ring becomes less slippery.

In particular, as in the invention of claim 2 or 3,
If the power transmission delay means is made of an annular rubber material, the rubber material absorbs and attenuates vibration and impact even when vibration or impact is applied from the belt side. As a result, the above-described vibration and impact are not transmitted to the one-way clutch, and the operation thereof can be stabilized.

Further, when a rubber material is provided as a power transmission delay means on the outer diameter side (for example, the outer ring) of the one-way clutch as in the second aspect of the invention, the one-way clutch may be provided as in the third aspect of the invention. As compared with the case where a rubber material is provided as a power transmission delay means on the inner diameter side (for example, an inner ring) of the above, the adjustment range of the elasticity of the rubber material can be increased, so that the degree of freedom in design increases.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
Description will be made based on the embodiment shown in FIG.

FIGS. 1 to 4 relate to a first embodiment of the present invention. FIG. 1 is a longitudinal sectional side view of an upper half of a pulley unit.
FIG. 2 is a sectional view taken along line (2)-(2) of FIG.
Is a longitudinal sectional front view of only the one-way clutch, and FIG. 4 is an exploded plan view of a pocket portion of a retainer of the one-way clutch.

The illustrated pulley unit A includes two inner and outer rings 1, 2 arranged concentrically, a one-way clutch 3 interposed in an annular space between the two rings 1, 2, and 2 disposed on both axial sides of the one-way clutch 3 in the annular space.
And two rolling bearings 4. In operation, the one-way clutch 3 is switched between a free state and a locked state in accordance with the rotational speed difference between the outer ring 1 and the inner ring 2, and the rotational power from the outer ring 1 to the inner ring 2 is changed. Block or transmit.

Hereinafter, each of the above components will be described in detail.

A circumferential groove around which the belt 5 is wound is formed on the outer periphery of the outer ring body 1 in a wavy manner. In addition, the inner ring 2 is attached with a rotating shaft such as a crankshaft of an engine or a drive shaft of an accessory provided in an automobile. The two rolling bearings 4 and 4 are formed of a general deep groove ball bearing.

The one-way clutch 3 includes an inner ring 10 and an outer ring 1
1, a retainer 12, a plurality of rollers 13, and a coil spring 14 are configured as follows.

The inner ring 10 is provided with a flat key-shaped cam surface 15 at several places on the outer peripheral surface thereof, and the outer peripheral surface is formed substantially in an octagon.

The outer ring 11 has a cylindrical inner and outer peripheral surface, and the inner peripheral surface and the cam surface 15 of the inner ring 10 form a wedge-shaped space. At both ends in the axial direction of the outer ring 11, thin extension portions 11a and 11b are provided, and the rolling bearings 4 and 4 are press-fitted on the inner periphery of the extension portions 11a and 11b, and the one-way clutch 3 Two rolling bearings 4,
4 can be handled integrally.

The cage 12 is provided in a radially opposed gap between the inner race 10 and the outer race 11 and has a pocket 12a penetrating inward and outward in the radial direction at a position corresponding to the cam surface 15. The retainer 12 is fixed to the inner race 10 in a state where the movement in the circumferential direction and the axial direction is sealed. In other words, at two positions 180 degrees opposite to one end surface in the circumferential direction of the inner ring 10, a slit-shaped recess 10 a that opens toward the shaft end and opens inward and outward in the radial direction is provided. A pair of convex portions 12b which are press-fitted into the concave portion 10a from the axial direction are respectively provided on the outer periphery on the side, and the retainer 12 is fixed to the inner ring 10 by these fittings.

The roller 13 and the coil spring 14 are housed one by one in each pocket 12a of the retainer 12 so as to be adjacent to each other in the circumferential direction. The coil spring 14 is housed in a compressed state, and resiliently urges the roller 13 toward the narrow side (lock side) of the wedge-shaped space by the expansion restoring force. The coil spring 14 is a rectangular wound spring in which a spring wire is wound in a rectangular shape, and is externally fitted to a projection 12c formed integrally with the inner surface of the pocket 12a of the retainer 12.

Next, the features of the present invention will be described. Between the outer ring 1 and the outer ring 11 of the one-way clutch 3, an annular rubber material 20 as power transmission delay means is interposed. The rubber material 20 is fixed to the outer peripheral surface of the outer ring 11 (or the inner peripheral surface of the outer ring body 1) by baking or the like. The rubber material 20 has an outer diameter slightly larger than the inner diameter of the outer ring 1 in a free state, and is pressed into the inner periphery of the outer ring 1.

In this configuration, the rollers 1 of the one-way clutch 3
When the locking member 3 is engaged with the narrow side of the wedge-shaped space and is locked, the one-way clutch 3 and the rubber member 20 connect the driving-side ring 1 (or 2) to the driven-side ring 2 (or 1). Power transmission.

If the outer ring 1 is rotationally driven by the belt 5, for example, when the one-way clutch 3 is locked, the rubber material 20 is twisted in the circumferential direction. Power transmission to the inner ring 2 is not performed instantaneously, but power is gradually transmitted from the outer ring 1 to the inner ring 2 as the shear resistance of the rubber material 20 increases. Thus, even if the one-way clutch 3 locks, the outer ring 1
The transmission of power from the motor to the inner ring 2 is not performed instantaneously but is performed with a slight delay, and the rotational speed difference between the two rings 1 and 2 does not instantly become zero. That is, since the mass of the inner ring 2 is gradually applied to the outer ring 1 without being instantaneously applied thereto, an excessively large rotational braking force does not act on the outer ring 1 instantaneously. Therefore, the belt 5 wound around the outer ring body 1 does not slip.

As described above, the impact force generated when the one-way clutch 3 is locked by the torsion of the rubber material 20 can be attenuated, and the slip of the belt 5 is suppressed.
Further, since the rubber material 20 can also absorb and attenuate vibrations and impacts from the belt 5 side, the rubber material 20 is not transmitted to the one-way clutch 3 and its operation can be stabilized.

By the way, the pulley unit A described above
For example, it can be mounted on an alternator of an engine. In this case, the rotation of the alternator rotor can be maintained at a high speed irrespective of the rotation fluctuation of the crankshaft of the engine which is the driving source of the belt 5, so that the power generation efficiency can be increased. That is, when the rotational speed of the crankshaft increases, the one-way clutch 3 is locked to rotate the inner ring 2 synchronously with the outer ring 1, while when the rotational speed of the crankshaft decreases, The one-way clutch 3 is in a free state and the inner ring 2
May be continued by its own rotational inertia force regardless of the deceleration of the outer ring 1. In such a usage form, although the rotation speed of the engine tends to fluctuate and the one-way clutch 3 is frequently switched,
Since the slip of the belt 5 can be suppressed, the result is that the service life of the belt 5 and the pulley unit A can be extended.

It should be noted that the present invention is not limited to the above embodiment, and various modifications are possible.

(1) Embodiment 2 of the present invention is shown in FIG. In the second embodiment, the power transmission delay means is provided on the inner ring body 2 side. That is, the inner ring 2 is formed in a double structure including the first ring 2A and the second ring 2B extrapolated to the first ring 2A, and is formed between the first and second rings 2A and 2B. An annular rubber member 20 as a power transmission delay unit is interposed. The rubber member 20 is fixed to the first ring 2A and the second ring 2B of the inner ring 2 by baking or the like. Note that, in this case, the outer race 11 of the one-way clutch 3 has an extended portion 11 as shown in FIG.
a, 11b, and rolling bearings 4, 4
May be directly fitted.

(2) In connection with the technical idea of the second embodiment, although not shown, the outer ring 1 is formed into a double structure composed of two rings, and a rubber material 20 is interposed between them. It may be. In this case, the one-way clutch 3
The outer ring 11 of FIG.
The rolling bearings 4 and 4 may be directly fitted to the outer ring body 1 without providing the 11b.

(3) Embodiment 3 of the present invention is shown in FIG. In the third embodiment, the outer race 11 of the one-way clutch 3
A wide circumferential groove 11c is formed on the outer peripheral surface of the rubber member, and a rubber material 20 as a power transmission delay means is fitted therein and fixed by baking or the like. The rubber material 20 is free in the circumferential groove 11c.
It has an outer diameter that projects slightly, and is pressed into the inner periphery of the outer ring 1. In the outer race 11, both side portions of the circumferential groove 11c are rotatably fitted to the inner circumference of the outer ring body 1.

(4) Embodiment 4 of the present invention is shown in FIG. In the fourth embodiment, the inner peripheral surface of the outer ring 1 and the outer peripheral surface of the outer ring 11 of the one-way clutch 3 are fitted in a rotatable state, and are fixed to the inner peripheral surface of the outer ring 1 in the circumferential direction. An axial groove 1a formed at a pitch and an axial groove 11d formed at a constant pitch on the outer peripheral surface of the outer race 11.
Are opposed to each other, and a rubber material 20 as power transmission delay means is interposed between the two concave grooves 1a and 11d.

(5) Embodiment 5 of the present invention is shown in FIG. In the fifth embodiment, the inner teeth 1b formed on the inner periphery of the outer ring body 1 and the outer teeth 11e formed on the outer peripheral surface of the outer ring 11 of the one-way clutch 3 are combined with a rubber material 20 as a power transmission delay unit. Are engaged via In this case, the rubber material 2
Since power is transmitted in a state where 0 is compressed in the circumferential direction,
Power transmission loss can be suppressed. In addition, if the tips of the external teeth 11e and the roots of the internal teeth 1b are slidably contacted in the circumferential direction, the rotational runout of the outer ring body 1 can be prevented.

(6) A sixth embodiment of the present invention is shown in FIGS. In the sixth embodiment, the inner peripheral surface of the outer ring 1 and the outer peripheral surface of the outer ring 11 of the one-way clutch 3 are fitted in a rotatable state, and a key formed on the inner peripheral surface of the outer ring 1. The groove 1c and the key groove 11f formed on the outer peripheral surface of the outer ring 11 are opposed to each other, and a metal spring 25 bent in a wave shape as power transmission delay means is fitted over both key grooves 1c and 11f.

[0037]

According to the first to third aspects of the present invention, the impact is prevented when the one-way clutch switches to the locked state, and the slip of the belt with respect to the outer ring body is suppressed. Belt abrasion and heat generation between the belt and the outer ring can be suppressed, thereby contributing to an increase in the durability of the belt and the pulley unit itself.

In particular, as in the invention of claim 2 or 3,
If the power transmission delay means is made of an annular rubber material, the rubber material absorbs and attenuates vibration and impact even when vibration or impact is applied from the belt side. As a result, the above-described vibration and impact are not transmitted to the one-way clutch, and the operation thereof can be stabilized.

In the case where a rubber material is provided as a power transmission delay means on the outer diameter side (for example, the outer ring) of the one-way clutch as in the invention of the second aspect, the one-way clutch as in the third aspect of the invention As compared with the case where a rubber material is provided as a power transmission delay means on the inner diameter side (for example, an inner ring) of the above, the adjustment range of the elasticity of the rubber material can be increased, so that the degree of freedom in design increases.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing an upper half of a pulley unit according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line (2)-(2) of FIG.

FIG. 3 is a longitudinal sectional front view of only the one-way clutch shown in FIG. 1;

FIG. 4 is an exploded plan view of a pocket portion of the cage of FIG. 2;

FIG. 5 is a longitudinal side view showing an upper half of a pulley unit according to a second embodiment of the present invention.

FIG. 6 is a longitudinal sectional side view showing an upper half of a pulley unit according to a third embodiment of the present invention.

FIG. 7 is a view corresponding to FIG. 2, showing an upper half of a pulley unit according to a fourth embodiment of the present invention.

FIG. 8 is a view corresponding to FIG. 2, showing an upper half of a pulley unit according to a fifth embodiment of the present invention.

FIG. 9 is a view corresponding to FIG. 2, showing an upper half of a pulley unit according to a sixth embodiment of the present invention.

FIG. 10 is a view taken along the line (x)-(x) in FIG. 9;

FIG. 11 is a longitudinal side view showing the upper half of a conventional pulley unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer ring 2 Inner ring 3 One-way clutch 4 Rolling bearing 10 Inner ring of one-way clutch 11 Outer ring of one-way clutch 20 Rubber material

Claims (3)

[Claims] 1. Two inner and outer rings arranged concentrically,
One direction that is interposed in an annular space between the two annular bodies and switches between a locked state in which one of the annular bodies and the other annular body are synchronously rotated according to a rotational speed difference between the two annular bodies and a free state in which the two are relatively rotated. A pulley unit including a clutch, wherein at least one of an outer diameter side and an inner diameter side of the one-way clutch delays power transmission between both rings when the one-way clutch is locked. A pulley unit provided with means. 2. The pulley unit according to claim 1, wherein the power transmission delay unit is interposed between the outer ring body and the outer ring of the one-way clutch in a state of being fixed to at least one of the two sides. A pulley unit characterized by being made of an annular rubber material. 3. The pulley unit according to claim 1, wherein the inner ring has a double structure including two inner and outer rings, and the power transmission delay means is provided between the two rings of the inner ring. A pulley unit, wherein the pulley unit is an annular rubber material interposed in a state of being fixed to at least one of the pulley units.