JP2001304381A - Pulley unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify constitution and reduce cost, while satisfying the function of absorbing angular velocity fluctuation of a driving ring body in a pulley unit. SOLUTION: A simple constitution, using only inner and outer rings 5 and 6 with two protruding parts 8 and 9, rather than not using a one-way clutch as in a conventional example, is provided between the driving ring body 3 and a driven ring body 2 as a constitution for absorbing the angular velocity fluctuation of the driving ring body 3, and each machining of the protruding parts 8 and 9 are simplified by providing a large gap in a mutual interlocking of the protruding parts 8 and 9. As a result of this, constitutional simplification and machining facilitation, in comparison to the conventional example, can be provided while almost equally absorbing the angular velocity fluctuation as in the conventional examples which use the one-way clutch.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulley unit. This pulley unit can be mounted on, for example, a crankshaft of an engine or an accessory driven from the crankshaft via a belt. 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 Conventionally, in a pulley unit, a roller type one-way clutch is incorporated between a pulley and a rotor shaft, and a one-way clutch is provided in accordance with an increase or a decrease in the angular velocity of a drive side of the pulley and the rotor shaft. In a lock state or a free state, rotational power is transmitted from a pulley to a rotor shaft or cut off to absorb angular velocity fluctuations on the drive side.

[0003]

In the above-mentioned conventional example, a one-way roller-type clutch is used. However, the components thereof need to be processed with high precision, and it can be said that the manufacturing cost is high. Under these circumstances, the demand for cost reduction, which has become increasingly severe as in recent years, cannot be satisfied, and there is room for improvement here.

[0004] In view of such circumstances, an object of the present invention is to provide a pulley unit that satisfies a function of absorbing a variation in angular velocity of a driving ring body, and realizes a simplified configuration and a low cost.

[0005]

SUMMARY OF THE INVENTION A first pulley unit according to the present invention has a driving ring and a driven ring disposed radially inward and outward via a bearing so as to be relatively rotatable. At least the circumference 1 of each of the peripheral surfaces facing the driven ring
A radially inwardly convex portion and a radially outwardly convex portion are integrally provided at two locations so as to mesh with each other in the rotational direction, and a gap for absorbing angular velocity fluctuation of the drive ring body is provided between the two convex portions. Is provided.

[0006] The second pulley unit of the present invention comprises the first pulley unit.
In the above configuration, the two convex portions are formed integrally with the two annular bodies.

[0007] The third pulley unit of the present invention comprises the first pulley unit.
In the above structure, an elastic body is attached to both circumferential end surfaces of the at least one convex portion.

[0008] The fourth pulley unit of the present invention comprises the first pulley unit.
Wherein the elastic body is interposed in the angular velocity fluctuation absorbing space secured between the two convex portions.

In short, according to the present invention, a gear (convex portion) having a large backlash (gap for absorbing angular velocity fluctuations) is provided on the driving ring and the driven ring, and their rotation directions are engaged. Thus, the driving ring is configured to transmit rotational power to the driven ring.

In this case, when the angular velocity of the driving ring is reduced, the backlash causes the convex portions to be disengaged from each other, and the rotational power is not transmitted from the driving ring to the driven ring. As a result, the angular velocity fluctuation of the driving ring is absorbed and is hardly transmitted to the driven ring.

As described above, in the present invention, since only the convex portion is provided as a configuration for absorbing the angular velocity fluctuation, the configuration can be simplified as compared with a conventional one-way clutch. In addition, since a backlash (gap) is provided for the engagement of the convex portions, the processing of each of the convex portions can be easily performed.

[0012] In particular, as in the third aspect of the present invention, if elastic bodies are provided on both circumferential end surfaces of at least one of the protrusions provided on the driving ring and the driven ring, that is, the contact surfaces, Collision noise does not need to be generated when the projections come into contact with each other.

Further, as in the fourth invention, if an elastic body is interposed in the gap for absorbing angular velocity fluctuation between the convex portions provided on the driving ring and the driven ring, the distance between the two convex portions can be reduced. The rattling of the rotation direction at is eliminated. The operation in this case is basically the same as described above. In other words, when the angular velocity of the drive ring increases, the elastic body is compressed by the protrusion on the drive ring being displaced toward the protrusion on the driven ring, and the rotational power of the drive ring is transmitted to the driven ring. On the other hand,
When the angular velocity of the drive ring is reduced, the elastic body is displaced toward the drive ring side by the inertia of the driven ring due to the rotational inertia force of the driven ring, so that the elastic body is compressed in the opposite direction to the above while the elastic body is compressed in the opposite direction. The engagement of the protruding portions is released, and a state in which rotational power is not transmitted from the driving ring to the driven ring is obtained.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described based on embodiments shown in the drawings.

1 to 4 show one embodiment of the present invention. 1 is a cross-sectional view showing the upper half of the pulley unit, FIG. 2 is a cross-sectional view taken along line (2)-(2) of FIG. 1, FIG. 3 is a cross-sectional view used for explaining the operation, and FIG. 6 is a table showing rotation waveforms of a pulley, a pulley and a rotor shaft.

The pulley unit 1 shown in the figure has a rotor shaft 2 and a pulley 3 which are concentrically arranged inside and outside the radial direction, and two pulley units which are arranged at both axial ends between the rotor shaft 2 and the pulley 3. The vehicle includes rolling bearings 4 and 4 and inner and outer races 5 and 6 for power transmission interposed in an annular space between the rotor shaft 2 and the pulley 3. In addition, the rolling bearing 4 can be a sliding bearing such as a brass bush. The number of rolling bearings 4 and sliding bearings used may be one.

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

The rotor shaft 2 is connected to, for example, a rotation shaft of an auxiliary machine provided in an automobile or a crankshaft of an engine.
Further, a wavy groove for winding the belt 7 is formed on the outer periphery of the pulley 3. Two rolling bearings 4, 4
Consists of general deep groove ball bearings.

Further, the inner and outer rings 5 and 6 for power transmission include
For example, the SAE 5120 is formed by subjecting the SAE 5120 to a surface hardening treatment (carburizing quenching, tempering), and is fitted and fixed to the rotor shaft 2 and the pulley 3 individually by press fitting. Two convex portions 8 projecting outward in the radial direction are formed at two locations facing each other on the outer peripheral surface of the inner ring 5, and two radially projecting portions are formed at the two locations facing each other on the inner peripheral surface of the outer race 6. The protruding projections 9 are provided integrally with each other.

The circumferential widths of the two pairs of projections 8 and 9 in the inner and outer rings 5 and 6 are set to be substantially the same as each other. The dimension is set to be larger than the circumferential width dimension of the projections 8 and 9. The space between the projections 8 and 9 serves as a gap for absorbing angular velocity fluctuations.

An elastic body 10 such as rubber is attached to both end faces in the circumferential direction of the convex portion 9 of the outer ring 6 by vulcanization bonding or an appropriate adhesive.

Next, the operation of the pulley unit 1 will be described. Here, the pulley unit 1 is used for an alternator of an automobile, and the pulley 3 is rotationally driven by a belt 7 rotationally driven by a crankshaft of an engine, and the rotor shaft 2 is connected to a rotor of the alternator. It is used in the form.

When the pulley 3 is driven to rotate by the belt 7, as shown in FIG. 3A, the convex portion 9 of the outer ring 6 integrated with the pulley 3 is integrated with the rotor shaft 2 in the process of increasing the angular velocity. The rotor shaft 2 rotates synchronously with the pulley 3 by abutting on and engaging with the convex portion 8 of the inner ring 5. At the time of the contact, no collision noise is generated due to the presence of the elastic body 10.

However, when the pulley 3 is instantaneously decelerated due to the angular speed fluctuation of the crankshaft, as shown in FIG.
Is disengaged by being separated from the convex portion 9 of the outer race 6, so that the pulley 3 does not transmit rotational power to the rotor shaft 2.

According to such a configuration, the fluctuation of the angular velocity of the crankshaft serving as the drive source of the pulley 3 is not transmitted to the rotor shaft 2. Note that an experiment has been performed for reference, and thus will be described.

The operating conditions are such that the pulley unit 1 as a sample is mounted on the alternator attached to the engine, the alternator rotation speed is 2000 rpm, and the load current of the alternator is 5 A.

As a result, as shown in the graph of FIG. 4, even when the angular velocity of the pulley 3 fluctuates slightly like a sine curve, the rotation waveform of the rotor shaft 2 becomes one. It has been confirmed that the fluctuation width is reduced in substantially the same manner as in the conventional example using the direction clutch. Also, as shown in the graph of FIG. 4, a one-way clutch is used for the tension fluctuation between the tension side (downstream in the rotational direction) and the loose side (upstream in the rotational direction) of the belt 7 wound around the pulley 3. As in the case of the conventional example, the result is that the fluctuation amount is suppressed to be small.

As described above, in the present embodiment, instead of using a one-way clutch as in the conventional example as a configuration for absorbing the angular velocity fluctuation, one of the above-mentioned two projections 8 and 9 is provided. Since the outer rings 5 and 6 are used and a large gap is provided for the engagement of the projections 8 and 9 with each other, the configuration is simplified, and the projections 8 and 9 are not processed with high precision. It can be done easily, for example. While simplifying such a configuration and processing, it is possible to absorb the angular velocity fluctuation almost in the same manner as in the conventional example using the one-way clutch as described above.

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

(1) In the above embodiment, an example is described in which the pulley 3 is a driving ring and the rotor shaft 2 is a driven ring. However, for example, when the pulley unit 1 is mounted on a crankshaft, , The rotor shaft 2 becomes a driving ring, and the pulley 3 becomes a driven ring. In this case, the operation is basically the same as that of the above embodiment.

(2) In the above embodiment, as shown in FIG. 5 and FIG. 6, the elastic body 11 such as rubber or a coil spring is provided in the space secured between the convex portions 8 and 9 of the inner and outer rings 5 and 6. May be interposed. In this case, there is an advantage in that rattling in the rotation direction between the two convex portions 8 and 9 can be eliminated. The operation in this case is basically the same as described above. That is, when the angular velocity of the pulley 3 increases,
As shown in FIG. 6A, the elastic body 1 is displaced by the protrusion 9 on the pulley 3 side being displaced toward the protrusion 8 on the rotor shaft 2 side.
1 is compressed, and in the process, the power transmission from the pulley 3 to the rotor shaft 2 is not instantaneously performed but gradually performed, and when the elastic body 11 reaches the compression limit, it becomes rigid. Power is transmitted from the pulley 3 to the rotor shaft 2. On the other hand, when the angular velocity of the pulley 3 decreases, FIG.
As shown in (b), when the protrusion 8 on the rotor shaft 2 is displaced toward the protrusion 9 on the pulley 3 side by the rotational inertia force of the rotor shaft 2, the elastic body 11 is compressed in the opposite direction. As a result, the engagement between the projections 8 and 9 is released and the pulley 3 does not transmit the rotational power to the rotor shaft 2. In this way, it is possible to prevent fluctuations in the angular velocity of the pulley 3 from being transmitted to the rotor shaft 2 without play in the rotation direction between the inner and outer rings 5 and 6. A washer is preferably interposed between the bearings 4 and 4 for axial positioning of rubber or a coil spring.

(3) Separately from the above embodiment, as shown in FIG. 7, the space between the pulley 3 and the rotor shaft 2 in the radial direction is
The roller type one-way clutch 20 is provided, and the pulley 3 and the outer race 22 of the one-way clutch 20 are arranged.
And a rubber damper 30 may be interposed between them. The one-way clutch 20 has a generally well-known configuration, and includes an inner race 21 and an outer race 2 as shown in FIGS.
2, a cage 23, a plurality of rollers 24, and a coil spring 25. A flat key-like cam surface 26 is provided at several places on the outer peripheral surface of the inner ring 21. The outer ring 22 has an inner and outer peripheral surface formed in a cylindrical shape.
And the cam surface 26 form a wedge-shaped space. Outer ring 2
Numeral 2 is extended in both axial directions in accordance with the axial dimension of the pulley 3, and both rolling bearings 4 and 4 are press-fitted on the inner periphery of the extended portion. The retainer 23 includes the inner ring 21
The inner ring 21 has a pocket 27 penetrating radially inward and outward at a position corresponding to the cam surface 26 of the inner ring 21 in a state where the movement in the circumferential direction and the axial direction is sealed. One roller 24 and one coil spring 25 are accommodated in the pocket 27 one by one in the circumferential direction. Although the basic operation in this configuration is well known, in short, the one-way clutch 20 is locked when the angular velocity of the pulley 3 increases, and the rotational power is transmitted to the rotor shaft 2. Direction clutch 2
0 is in a free state, and the rotational power is not transmitted to the rotor shaft 2, so that the angular velocity fluctuation of the pulley 3 is absorbed and is not transmitted to the rotor shaft 2. However, in this configuration,
Due to the presence of the rubber damper 30, when the one-way clutch 20 is in the locked state, power transmission is not performed instantaneously, but the rubber damper 30 is twisted in the circumferential direction to increase the shearing resistance. The transmission is delayed and occurs gradually. That is, the shock load at the moment when the one-way clutch 20 is locked is absorbed by the rubber damper 30, so that the operation of the belt 7 and the pulley 3 and the pulley 3 can be suppressed. The durability of the unit 1 itself can be increased.

[0033]

According to the first to fourth aspects of the present invention, a gear (convex portion) having a large backlash (gap for absorbing angular velocity fluctuation) is provided for the driving ring and the driven ring. The rotational power is transmitted from the driving ring to the driven ring by meshing in the rotational directions of the above, so that the angular velocity fluctuation of the driving ring is absorbed and is not transmitted to the driven ring. .

That is, in the present invention, at least a pair of convex portions are provided as a configuration for absorbing the angular velocity fluctuation, so that the configuration can be simplified as compared with a conventional one-way clutch. In addition to this, since a backlash (gap) is provided for the engagement of the convex portions, the processing of each of the convex portions can be easily performed, and a reduction in manufacturing cost can be achieved.

In particular, if an elastic body is provided on both circumferential end surfaces of at least one of the projections provided on the driving ring and the driven ring, that is, the contact surfaces, as in the invention of claim 3, No collision sound is generated when the two convex portions come into contact with each other, which contributes to stabilizing the operation.

Further, if the elastic body is interposed in the gap for absorbing angular velocity fluctuation between the convex portions provided in the driving ring and the driven ring as in the invention of claim 4, both convex portions are provided. There is no play in the rotation direction between them, which can greatly contribute to stabilization of operation.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an upper half 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 used to explain the operation of FIG. 1;

FIG. 4 is a chart showing rotation waveforms of a pulley and a rotor shaft.

FIG. 5 is a view corresponding to FIG. 2, showing a pulley unit according to another embodiment of the present invention.

FIG. 6 is a sectional view used to explain the operation of FIG. 5;

FIG. 7 is a sectional view showing the upper half of a pulley unit according to still another embodiment of the present invention.

8 is a sectional view taken along line (8)-(8) in FIG. 7;

FIG. 9 is a plan view showing a pocket portion of the retainer in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pulley unit 2 Pulley 3 Rotor shaft 4 Rolling bearing 5 Inner ring 6 Outer ring 7 Belt 8 Inner ring convex part 9 Outer ring convex part

Claims (4)

[Claims] 1. A driving ring and a driven ring disposed radially inward and outward relative to each other via a bearing, and at least circles of respective peripheral surfaces of the driving ring and the driven ring opposed to each other. A radially inward convex portion and a radially outward convex portion are integrally provided at one circumferential position so as to mesh with each other in the rotational direction. A pulley unit, characterized by being provided with an air gap. 2. The pulley unit according to claim 1, wherein said both convex portions are formed integrally with said both ring bodies. 3. The pulley unit according to claim 1, wherein elastic members are attached to both circumferential end surfaces of said at least one convex portion. 4. The pulley unit according to claim 1, wherein an elastic body is interposed in the gap for absorbing angular velocity fluctuation secured between the two convex portions.