JPH1182688A - Pulley unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize the operation of an one-way clutch and an anti-friction bearing for the long period of time in a pulley unit equipped with the one-way clutch. SOLUTION: Grease in an ether series is used by an one-way clutch 3 in a pulley unit including both two inner and outer annular bodies 1 and 2 coaxially disposed, and the one-way clutch interposed in an annular space between both the annular bodies 1 and 2. An oil film made of the grease is hardly cut off even when stresses are concentrated at the metallic contact portion of the one-way clutch 3, and loading can thereby be relaxed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a pulley unit having a one-way clutch. The pulley unit can be mounted on an accessory driven via a belt from a crankshaft of an engine of an automobile or the like, for example. As auxiliary equipment, for example, automobile alternator, air conditioner compressor, water pump,
Cooling fans.

[0002]

2. Description of the Related Art Various accessories mounted on an automobile engine are driven by a crankshaft of the engine via a belt. Here, among the auxiliary machines, particularly in the case of an alternator, when the crankshaft is connected so as to rotate synchronously with the engine, the power generation capacity of the alternator decreases when the rotation speed of the crankshaft decreases.

[0003] The applicant of the present invention mounts a one-way clutch on the alternator and increases the power generation efficiency by continuing the rotation of the alternator rotor by its inertia when the rotation speed of the crankshaft decreases. I'm thinking about that. That is, a one-way clutch is interposed between the pulley and the rotor of the alternator, and the one-way clutch is locked (power transmission state) and free state (power transmission cut-off state) according to the rotation difference between the pulley and the rotor. And power is transmitted or cut off between the pulley and the rotor. In addition, rolling bearings are provided on both sides of the one-way clutch to smooth the relative rotation between the pulley and the rotor and to bear the load.

[0004]

In the above-mentioned conventional example, a one-way clutch and two rolling bearings are disposed in an annular space between the pulley and the rotor. Seal members are attached to both ends, and the rolling bearings prevent grease applied to the one-way clutch from scattering outside.

[0005] For the one-way clutch, grease using base oil of PαO or urea grease is used, and for the rolling bearing, urea grease is used. This is the same as the case where the one-way clutch and the rolling bearing are used alone.

However, in the use environment of the alternator, since the vibration is almost always transmitted via the belt during operation, the following problems may occur in the one-way clutch and the rolling bearing mounted on the alternator. I understood. In other words, the concentration of stress near the surface of the raceway surface of the one-way clutch or rolling bearing due to vibration makes it easy for the grease oil film to break off at this location. A layer is formed, and a so-called white layer peeling phenomenon, in which the layer is peeled in a scaly shape starting from the layer, is likely to occur. When such a white layer peeling phenomenon occurs, noise increases.

Accordingly, an object of the present invention is to stabilize the operation of a one-way clutch and a rolling bearing for a long time in a pulley unit having a one-way clutch. It is another object of the present invention to simplify the configuration and reduce the cost of a pulley unit having a one-way clutch, while stabilizing the operation of the one-way clutch and the rolling bearing for a long time.

[0008]

According to a first aspect of the present invention, there is provided a pulley unit comprising two concentrically disposed inner and outer rings;
A one-way clutch interposed in an annular space between the two annular bodies, wherein ether-based grease is used for the one-way clutch.

According to a second aspect of the present invention, there is provided a pulley unit comprising: two inner and outer rings arranged concentrically; a one-way clutch interposed in an annular space between the two rings; Rolling bearings provided on both sides of the one-way clutch, wherein a sealing member is attached only to the axially outer end of each of the two rolling bearings, and the one-way clutch and the rolling are provided in the annular space closed by the sealing member. Ether-based grease shared with the bearing is sealed.

As described above, in the pulley unit of the present invention, the one-way clutch switches between the locked state and the free state in accordance with the rotation difference between the outer ring and the inner ring, and the one-way clutch switches between the outer ring and the inner ring. The power is transmitted or cut off between the two.

[0011] When an ether-based grease is used for the one-way clutch as in the pulley unit of the first aspect, the oil film does not easily break at the metal contact portion of the one-way clutch while exhibiting an excellent power transmission function. Therefore, the white layer peeling phenomenon is less likely to occur.

According to a second aspect of the present invention, the one-way clutch and the rolling bearings on both sides disposed in the annular space are lubricated by common grease.
There is no waste as compared with the case where they are separated. Moreover, means for partitioning the one-way clutch from the rolling bearing is not required. Further, also for the rolling bearing, damage to the raceway portion due to vibration is less likely to occur.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in FIGS.

1 to 4 relate to an 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) of FIG. 3 is an arrow view of a cross section taken along line (3)-(3) in FIG. 1, and FIG. 4 is a developed plan view showing a part 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 four rolling bearings 4 and 4.

On the outer periphery of the outer ring 1, a wavy groove for belt winding is formed, and the outer ring 1 is so-called V-shaped by a crankshaft of an automobile engine, for example.
It is designed to be rotationally driven via a belt B called a belt. The inner ring 2 is formed of a sleeve-shaped member, and is fixed to an input shaft of an auxiliary machine of an automobile (for example, a rotor of an alternator) (not shown).

The one-way clutch 3 includes an inner race 10 having a flat key-shaped cam surface 10a provided at several locations on the outer circumferential surface.
And a retainer 12 having an outer race 11 formed to be long in the axial direction so that the rolling bearings 4 and 4 are fitted at both ends, and a pocket 12a formed to penetrate inward and outward in the radial direction corresponding to the cam surface 10a. And a plurality of rollers 13 accommodated one by one in each pocket 12a of the retainer 12, and a plurality of rollers 13 accommodated one by one in each pocket 12a of the retainer 12, and
A coil spring 14 having a substantially rectangular cross section as an elastic member that presses toward the narrow side (lock side) of the wedge-shaped space between the outer ring 11 and the inner peripheral surface of the outer ring 11 is provided. The inner wall surface of the pocket 12a of the retainer 12 has a constricted projection 1 at the base.
2b is integrally formed, and one end of the coil spring 14 in the axial direction is locked and fitted to a constricted portion at the base of the projection 12b. It is designed to prevent distortion. In addition, a slit-shaped concave portion 10b that opens toward the shaft end and opens radially inward and outward is formed on one axial end surface of the inner race 10 of the one-way clutch 3.
A concave portion 10b is formed on the inner circumferential side of one end of the retainer 12 in the axial direction.
Each of the projections 12c is press-fitted from the axial direction into the retainer 12, and the movement of the retainer 12 in the circumferential direction is blocked by the press-fitting of the recess 10b and the projection 12c.
Further, the convex portion 12c is formed between the inner wall surface of the concave portion 10b and the concave portion 10b.
b, the inner ring 16 of one of the rolling bearings 4 disposed on the opening side
Is axially sandwiched between the end faces of the retainer 12, thereby blocking the movement of the retainer 12 in the axial direction.

Each of the two rolling bearings 4 and 4 comprises a general deep groove ball bearing having an inner ring 16, an outer ring 17, a plurality of balls 18 and a retainer 19, and a shaft between the inner and outer rings 16 and 17. The seal member 20 is mounted only on the outer end side in the direction. The annular space in which the one-way clutch 3 and the rolling bearings 4 and 4 are disposed is closed by the two seal members 20.

In this embodiment, ether-based grease is applied to the one-way clutch 3 and the two rolling bearings 4 and 4 disposed in the annular space closed by the seal member 20. The two rolling bearings 4 and 4 and the one-way clutch 3 share grease. As the ether-based grease, for example, a grease whose thickener is diurea and whose base oil is mainly alkyldiphenyl ether is used.

Next, the operation of the pulley unit A will be described. In short, when the rotation 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 to be in the locked state, so that the outer ring 1 is locked. The body 1 and the inner annular body 2 are integrated and rotate synchronously. However, when the rotation speed of the outer ring 1 is relatively lower than that of the inner ring 2, the rollers 13 of the one-way clutch 3
Since the inner ring 2 is rolled to the wide side of the wedge-shaped space to be in a free state, the transmission of rotational power from the outer ring 1 to the inner ring 2 is interrupted, so that the inner ring 2 has only the rotational inertia force. To continue the rotation.

If this pulley unit A is used as an alternator, the rotation of the alternator rotor is maintained at a high range regardless of the rotational fluctuation of the engine crankshaft, which is the driving source of the belt B, and the power generation efficiency is improved. 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 an alternator, since the pulley unit A frequently receives vibration from the engine, the one-way clutch 3 and the rolling bearings 4, 4 of the pulley unit A are used.
Although stress concentration tends to occur at the metal contact area, as described above, if ether-based grease is used,
Since the oil film is less likely to break at the metal contact portion and the load can be reduced, it is possible to prevent the occurrence of the white layer peeling phenomenon at this portion.

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

(1) 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 types of leaf springs and elastic pieces can be used instead.

(2) In the above embodiment, an example is described in which the cam surface 10a of the one-way clutch 3 is formed on the inner ring side. However, the present invention can be applied to the one provided on the outer ring side. However, in the case of the above-described embodiment, it is suitable for use in high-speed rotation, such that the rollers can be prevented from unnecessarily coming out of the locked position due to centrifugal force even in the high-speed rotation range.

[0026]

According to the first aspect of the present invention, since an ether-based grease is used for the one-way clutch, the oil film is less likely to be broken at the metal contact portion, and the load can be reduced. Therefore, the white layer peeling phenomenon is less likely to occur at the metal contact portion, and as a result, the life can be extended.

According to the second aspect of the present invention, the annular space in which the one-way clutch and the rolling bearings on both sides in the axial direction are disposed is closed by the sealing member at the axially outer end of the rolling bearing. And the rolling bearings on both sides share the same grease, which reduces waste compared to using separate grease.
It can contribute to cost reduction. In addition, there is no need for a partitioning means for preventing grease mixing between the one-way clutch and the rolling bearing, which can contribute to cost reduction in this respect as well. Furthermore, also in a rolling bearing, a white layer peeling phenomenon is less likely to occur in a situation where vibration is frequently received.

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 concentrically disposed inner and outer rings can be increased. Can contribute to improvement.

[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) of FIG.

FIG. 3 is a sectional view taken along line (3)-(3) of FIG.

FIG. 4 is a developed plan view showing a part of the one-way clutch.

[Explanation of symbols]

 A pulley unit B belt 1 outer ring 2 inner ring 3 one-way clutch 4 rolling bearing

Claims (2)

[Claims] 1. Two inner and outer rings arranged concentrically,
A pulley unit including a one-way clutch interposed in an annular space between both ring bodies, wherein an ether-based grease is used for the one-way clutch. 2. An inner and outer ring which is arranged concentrically,
A one-way clutch interposed in the annular space between the two annular bodies,
A pulley unit including rolling bearings provided on both sides of a one-way clutch in the annular space, wherein a seal member is attached only to each axially outer end of the two rolling bearings, and the annular member is closed by the seal member. A pulley unit characterized in that ether-based grease shared by a one-way clutch and a rolling bearing is sealed in a space.