JPH0937514A - Bearing device and generator having the device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a bearing device which has a coil spring and functions as a one-directional clutch function smoothly and securely. SOLUTION: A plurality of rolling elements 10, inner and outer rings 8 and 9 and a coil spring 12 whose one end 12b is retained with the outer ring 9 and, further, which is put onto the circumference of an extended cylindrical part 8a provided on the inner ring 8 with a required tightening allowance are provided. If the outer ring 9 is turned in the winding direction of the coil spring 12, the diameter of the coil spring 12 is reduced and the coil spring 12 is wound around the extended cylindrical part 8a of the inner ring 8 to turn the outer ring 9 and the inner ring 8 synchronously. On the other hand, if the outer ring 9 is turned in the direction opposite to the winding direction of the coil spring 12, the outer ring 9 idles around the inner ring 8. As a radial load applied to the outer ring 9 is received by roller bearing elements, it does not interfere the operation of the coil spring 12.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a bearing device, and
It relates to a generator equipped with it.

[0002]

2. Description of the Related Art An alternator such as an alternator of an automobile is driven by the rotational power of a crankshaft of an automobile engine.

That is, a belt is wound around a pulley integrally fitted on a drive shaft of an alternator and a pulley integrally fitted on a crankshaft of an automobile engine. In this case, the rotating power of the crankshaft pulley directly drives the alternator pulley. Therefore, when the crankshaft is rapidly decelerated from the state of being rotated at a high speed, the inertia moment of the alternator causes the belt to slide on the pulley of the alternator. When this slippage occurs, an abnormal sound is produced, and the belt is damaged and the life is shortened.

On the other hand, as disclosed in Japanese Unexamined Patent Publication No. 5-180287, it is considered that a coil spring is mounted between a rotary shaft and a pulley so as to function as a one-way clutch. The coil spring is loosely fitted to a metal cylinder screwed to the outer peripheral surface of the rotary shaft, and one end of the coil spring is locked to the pulley.

The operation of this coil spring will be described. First,
When the one end side of the coil spring moves in the same direction as the pulley rotates in one direction, the diameter of the coil spring gradually decreases, and the coil spring is wound around the rotating shaft, so that the pulley and the rotating shaft are integrated. Will rotate synchronously. When the pulley suddenly decelerates from this state, the coil spring gradually expands in diameter due to the moment of inertia of the rotating shaft and returns to the original state, and the coil spring loosens from the rotating shaft.
The coil spring and the pulley will idle around the rotation axis.

As described above, with respect to the rotation of the pulley in one direction, the rotational power is transmitted from the pulley to the rotating shaft, but when the speed difference between the pulley and the rotating shaft becomes large, the pulley moves relative to the rotating shaft. It rotates and stops transmitting rotational power. Therefore, the belt does not slip on the pulley during sudden deceleration.

[0007]

By the way, the above-mentioned conventional example has the following problems.

(1) A coil spring is interposed between the pulley and the rotary shaft, and the load applied to the pulley (belt tension)
Since it directly acts on the coil spring, the ideal operation as the one-way clutch as described above is not always surely performed, and the reliability is considered to be low. In the drawings of the publication, a ball bearing is seen beside the pulley and the coil spring, but the ball bearing is not designed to receive the load applied to the pulley.

(2) When the pulley is idling, the coil spring is in sliding contact with the metal cylinder externally fitted and fixed to the rotating shaft, but since lubrication there is not taken into consideration, the metal cylinder is significantly worn or seized. The durability is questionable, such as the occurrence of

Therefore, it is an object of the present invention to provide a bearing device having a coil spring that functions as a one-way clutch so that the function can be smoothly and reliably performed.

Further, according to the present invention, in a generator driven via a pulley, when the pulley rotating at a high speed is rapidly decelerated, slippage between the pulley and the belt wound around the pulley is prevented, and the belt is damaged. The purpose is to be able to avoid the occurrence of abnormal noise.

[0012]

A bearing device according to the present invention has a plurality of rolling elements, an inner / outer ring, and one of the inner / outer ring, one end of which is fixed to the other of the inner / outer ring. And a coil spring fitted with a required interference with the peripheral surface of the extended tubular portion.

In the generator of the present invention, a rotating shaft of the rotor is rotatably supported by a frame provided with a stator via a pair of bearings, and a pulley is provided at an end of the rotating shaft protruding outside the frame. The bearing device described above is interposed between the pulley and the rotary shaft.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the embodiments shown in FIGS. 1 and 2
1 is a longitudinal sectional view of the alternator, and FIG. 2 is a sectional view taken along line (2)-(2) of FIG.

Prior to the description of the embodiments of the present invention, an example of an auxiliary machine driving mode of an automobile engine will be briefly described with reference to FIG. In FIG. 4, 1 is an automobile engine, 2
Is a crank pulley, 3 is an alternator, 4 is an alternator pulley, 5 is a belt, and 6 is a tension pulley.
When the crank pulley 2 rotates, the alternator pulley 4 is rotationally driven via the belt 5.

A bearing device 7 as shown in FIGS. 1 and 2 is interposed between the rotating shaft 3a of the alternator 3 and the alternator pulley 4.

The bearing device 7 includes inner and outer rings 8 and 9, balls 10 as a plurality of rolling elements, a corrugated cage 11, a coil spring 12, and a seal member 13.

The outer ring 9 has the same size as that of a general bearing, but the inner ring 8 is provided with a cylindrical extension tube portion 8a on one side in the axial direction. These inner and outer rings 8, 9
Is made of bearing steel or the like, and in particular, the surface roughness of the outer peripheral surface of the extension cylindrical portion 8a of the inner ring 8 is set to 0.8 z or less.

The seal member 13 is fitted in a circumferential groove formed on the inner peripheral surface of the shoulder portion of the outer ring 9 on the other side in the axial direction, and has a taper surface formed on the outer peripheral surface of the shoulder portion of the inner ring 8. A contact sealing part or a non-contact sealing part is formed between them.

The coil spring 12 is an extension cylinder portion 8a of the inner ring 8.
The spiral portion 12a fitted onto the outer peripheral surface of the outer peripheral surface of the outer peripheral surface of the outer peripheral surface of the outer peripheral surface of the outer peripheral surface of the outer peripheral surface of the outer peripheral surface of the outer peripheral surface of the outer peripheral surface of the outer peripheral surface of the outer peripheral surface of the outer peripheral surface of the outer peripheral surface of the outer ring 9 at one end in the axial direction of the outer ring 9. And a radially outwardly extending portion 12b that is locked. The coil spring 12 has a substantially rectangular cross section and is made of spring steel.

A seal member 14 is attached to one end of the inner peripheral surface of the center hole of the alternator pulley 4, and the inner periphery of the seal member 14 is the extension cylinder portion 8a of the inner ring 8 of the bearing device 7. A contact seal portion or a non-contact seal portion is formed between the outer peripheral surface and the outer peripheral surface. This seal member 14
The seal member 13 of the bearing device 7 seals the lubricant present in the facing gap between the inner and outer rings 8 and 9 of the bearing device 7 and the space where the coil spring 12 is present.

Next, the operation will be described. First, when the alternator pulley 4 and the outer ring 9 of the bearing device 7 rotate in the winding direction of the coil spring 12 as the crank pulley 2 rotates, the extending portion 12b of the coil spring 12 moves in the same direction, and the spiral portion 12a of the coil spring 12 moves. The diameter is gradually reduced, and eventually the extension cylinder portion 8 of the inner ring 8 of the bearing device 7 is reduced.
Since it is wound around a, the alternator pulley 4
The outer ring 9 of the bearing device 7, the inner ring 8 and the rotating shaft 3a of the alternator 3 are integrated with each other so that they rotate synchronously.

From this state, when the alternator pulley 4 and the outer ring 9 of the bearing device 7 are rapidly decelerated, the inner ring 8 and the rotating shaft 3a of the alternator 3 are not rapidly decelerated by the moment of inertia, so that the alternator pulley 3 and the bearing device 7 are decelerated. The rotation of the outer ring 9 is relatively slower than the rotation of the inner ring 8 and the rotating shaft 3a of the alternator 3. This allows
Since the coil spring 12 is gradually expanded so as to restore its original state and loosens from the extension cylinder portion 8a of the inner ring 8, the coil spring 12 and the outer ring 9 are extended from the extension cylinder portion 8 of the inner ring 8.
It will idle around a. Therefore, the alternator pulley 4 can maintain the rotation substantially in synchronization with the crank pulley 2, the belt 5 does not slip with respect to the alternator pulley 4, and the damage and abnormal noise of the belt 5 are avoided. Even when the outer ring 9 rotates in the direction opposite to the winding direction of the coil spring 12, the coil spring 12 and the outer ring 9 idle around the inner ring 8.

By the way, a load such as a belt tension applied to the alternator pulley 4 is received by the rolling bearing element of the bearing device 7, and therefore does not act on the coil spring 12 at all. Therefore, the diameter reduction and diameter expansion operations of the coil spring 12 are smoothly performed. In addition, the coil spring 12 has the inner ring 8
Although it may come into sliding contact with the outer peripheral surface of the extension cylinder portion 8a, wear and damage of the inner ring 8 are suppressed because the inner ring 8 is surface-hardened such as bearing steel. Moreover, a lubricant such as grease for bearing lubrication sealed by the two seal members 13 and 14 is supplied between the coil spring 12 and the outer peripheral surface of the extension cylinder portion 8a of the inner ring 8. Since the coil spring 12 and the extension cylinder portion 8a of the inner ring 8 are lubricated, abnormal heat generation between the two can be avoided and seizure can be prevented. However,
Even if the lubricant is present between the coil spring 12 and the extension cylinder portion 8a of the inner ring 8, the winding around the extension cylinder portion 8a of the coil spring 12 is not hindered, and reliable winding can be performed. Power transmission from the pulley 4 to the rotating shaft 3a of the alternator 3 is reliably and efficiently performed.

FIG. 3 shows another embodiment of the present invention.
FIG. The difference between this embodiment and the above embodiment is the shape of the inner and outer rings 8 and 9 of the bearing device 7 and the mounting form of the coil spring 12.

Specifically, the inner and outer races 8 and 9 have the opposite shapes to those of the above embodiment. That is, the inner ring 8 has the same size as that of a general bearing, but the outer ring 9 has
A cylindrical extension cylinder portion 9b is provided on one side in the axial direction.

The extension 12b of the coil spring 12 is directed inward in the radial direction, the extension 12b is locked to the notch 8b of the inner ring 8, and the spiral portion 12a of the outer ring 9 is formed. The extension cylindrical portion 9b is fitted into the inner peripheral surface with a required interference.

The inner ring 8 and the rotating shaft 3 of the alternator 3
A spacer 16 is provided between the nut 15 and the nut 15 that is screwed to the a, and a seal member 14 is provided between the spacer 16 and the outer ring 9.

Next, as the operation, when the outer ring 9 is rotated in the direction opposite to the winding direction of the coil spring 12, the coil spring 12 gradually expands in diameter due to the frictional resistance with the outer ring 9, and the extension tube of the outer ring 9 is expanded. Since it is pressed against the inner peripheral surface of the portion 9b, the outer ring 9 and the inner ring 8 are integrated and rotate synchronously.

From this state, when the rotation of the outer ring 9 becomes relatively slower than the rotation of the inner ring 8, the coil spring 12 is gradually reduced in diameter so as to restore the original state, and the outer ring 9
Since the pressing force on the extension cylindrical portion 9b is reduced, the coil spring 12 and the outer ring 9 idle around the inner ring 8. Even if the outer ring 9 rotates in the winding direction of the coil spring 12, the coil spring 12 and the outer ring 9 idle around the inner ring 8.

Also in this case, the one-way clutch function of the coil spring 12 is smoothly and surely performed, as in the above embodiment.

It should be noted that the present invention is not limited to only the above-described embodiment, and various applications and modifications are conceivable. An example in which the bearing device 7 is provided between the rotating shaft 3a of the alternator 3 and the alternator pulley 4 is given, but other automobile auxiliary equipment (hydraulic pump of power steering device,
Air conditioner compressors, etc.) can also be installed.

[0033]

In the bearing device of the present invention, even if a load is applied to the outer ring, the load is not applied to the coil spring functioning as a one-way clutch, so that the one-way clutch function is not hindered. In addition, reliability and life can be improved, such as smooth and reliable operation.

In the generator of the present invention, when the pulley is rapidly decelerated, the pulley and the rotating shaft are relatively rotated to prevent the belt wound around the pulley from slipping. As a result, damage to the belt and the generation of abnormal noise can be avoided, which contributes to a longer service life of the peripheral members.

In particular, since the bearing device of the present invention uses the rolling bearing element and the coil spring that performs the one-way clutch function as a unit, the assembling property with respect to the object of use such as a generator is easy and favorable, and the rolling bearing element is also provided. Since the lubricant is diverted from the coil spring to the coil spring, there is an effect that maintenance can be omitted.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an alternator 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 diagram corresponding to FIG. 1 in another embodiment of the present invention.

FIG. 4 is an explanatory view schematically showing an example of an accessory drive mode of an automobile engine.

[Explanation of symbols]

 3 Alternator 4 Alternator pulley 7 Bearing device 8 Inner ring of bearing device 8a Inner ring extension of inner ring 9 Outer ring of bearing device 9a Cutout of outer ring 10 Ball of bearing device 12 Ball spring of bearing device 12a Coil spring of coil spring 12b Extension of coil spring

Claims (2)

[Claims] 1. A plurality of rolling elements, an inner / outer ring, and one end of the inner / outer ring are engaged with each other, and are required for the peripheral surface of an extension cylindrical portion provided on the other of the inner / outer ring. A bearing device comprising: a coil spring fitted with a interference. 2. A generator in which a rotating shaft of a rotor is rotatably supported by a frame provided with a stator via a pair of bearings, and a pulley is provided at an end of the rotating shaft protruding outside the frame. A generator, wherein the bearing device according to claim 1 is interposed between a pulley and a rotary shaft.