JP2001248648A - Cage for rolling bearing and rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce dynamic torque while preventing the generation of cage noise. SOLUTION: Chamfering 13 is applied only to a peripheral fringe part of an opening on outside diameter side among peripheral fringe parts of openings at both ends of each pocket 10, 10. The peripheral fringe part of the opening on inside diameter side is a sharply pointed end fringe 14. A sufficient amount of grease is taken in each pocket 10, 10 from outside diameter side to prevent an excessive amount of grease from entering from inside diameter side so as to achieve the above-mentioned purpose.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The cage and the rolling bearing for a rolling bearing according to the present invention provide a hard disk drive (HD).
D) Rolling bearings to be incorporated as rotation supporting parts for various devices, such as rolling bearings to be incorporated as rotating supporting parts for various electric devices such as spindle motors of video tape recorders (VTR), digital video disks (DVD), mini disks (MD), etc. In addition, the present invention relates to an improvement of a cage incorporated in this rolling bearing to guide a plurality of rolling elements in a freely rolling manner.

[0002]

2. Description of the Related Art Rolling bearings 1 as shown in FIG. 6 are widely used to rotatably support a rotating portion such as a rotating shaft which constitutes various devices with respect to a fixed portion such as a housing. In this rolling bearing 1, an inner race 3 having an inner raceway 2 formed on the outer peripheral surface and an outer race 5 having an outer raceway 4 formed on the inner peripheral surface are arranged concentrically, and between the inner raceway 2 and the outer raceway 4 described above. A plurality of balls 6, 6 each of which is a rolling element, are provided so as to freely roll. The plurality of balls 6, 6 are rotatably held by a holder 8. The outer peripheral edges of the annular shield plates 7 and 7 are engaged with the inner peripheral surfaces of both ends of the outer ring 5, respectively, and the grease existing in the portion where the balls 6 and 6 are installed is secured by the shield plates 7 and 7. Is prevented from leaking to the outside, or dust floating outside is prevented from entering the installation portion. In addition, as a sealing device,
Instead of the non-contact type shield plates 7, 7, a contact type seal plate may be used.

In the case of the illustrated example, the retainer 8 is a so-called crown type retainer, and is configured as shown in FIGS. The retainer 8 includes an annular main portion 9 and a plurality of pockets 10 and 10 provided at equal intervals on one axial surface of the main portion 9. These pockets 10, 1
0 is a pair of elastic pieces 1 spaced apart from each other
1 and 11 and a concave portion 12 provided on one surface of the main portion 9 (the upper surface in FIGS. 8 to 9) and between the pair of elastic pieces 11 and 11 respectively. 8 are open on the inner diameter side and the outer diameter side. Each of the balls 6, 6 is held in each of the pockets 10, 10 so as to be able to roll freely. Each pocket 1 configured in this way
The inner surfaces of 0 and 10 are entirely spherical concave surfaces, and the radius of curvature of the spherical concave surface is slightly larger than the radius of curvature of the rolling surfaces of the balls 6 and 6. Such a cage 8
Are integrally formed by injection molding a synthetic resin.

[0004] Each of the balls 6, 6 is connected to each of the pockets 10,
The pair of elastic pieces 11, 11 forming the pair 10 are pushed into the space between the pair of elastic pieces 11, 11 while elastically expanding the interval between the distal ends thereof. Then, in the pushed-in state, as shown in FIG. 10, the balls 6, 6 are rollably held in the pockets 10, 10, respectively. In this state, there is a small gap between the rolling surface of each of the balls 6, 6 and the inner surface of each of the pockets 10, 10. Therefore, in a state where the balls 6, 6 are held in the pockets 10, 10, the retainer 8 holds the balls 6, 6 at equal intervals in the circumferential direction, and also holds the balls 6, 6 in the circumferential direction. This regulates the position of the retainer 8 in the diameter direction.

[0005] The lubrication of the rolling bearing 1 incorporating the cage 8 as described above is generally performed by grease injected between a pair of shield plates 7. In order to smoothly rotate the rolling bearing 1 based on the lubrication of the grease, it is necessary to provide an appropriate space between the rolling surfaces of the balls 6, 6 and the inner surfaces of the pockets 10, 10. It is necessary that a quantity of grease be present. In view of such circumstances, Japanese Unexamined Patent Application Publication No. 11-141558 discloses that, as shown in FIG. 11, the inner peripheral side (lower side in FIG. 11) and the outer peripheral side (upper side in FIG. A bearing for a rolling bearing, in which chamfers 13 and 13 are formed in a portion, is described.

In the case of the rolling bearing cage described in the above-mentioned publication, grease adhering to the rolling surface of the ball 6 held in the pocket 10 due to the presence of the chamfers 13, 13. It is efficiently taken in between the rolling surface of the ball 6 and the inner surface of the pocket 10. Further, in the above-mentioned publication, the use of a grease composed of a thickening agent made of a urea compound and a base oil containing polyphenyl ether as a main component as the above-mentioned grease provides high-temperature / high-speed durability and low-temperature sound startup. A technique for improving characteristics is described.

[0007]

In the case of the conventional structure shown in FIG. 11, grease can be efficiently taken in between the rolling surface of the ball 6 and the inner surface of the pocket 10, but the amount of grease taken in becomes too large. Thus, it has been found from the experiments of the present inventors that the dynamic torque of the rolling bearing increases. That is, in the case of the above-mentioned conventional structure, since the chamfers 13 and 13 are formed on the inner peripheral side and the outer peripheral side of the pocket 10, most of the grease adhering to the rolling surface of the ball 6 is removed. , Enter the pocket 10 without being scraped off at the peripheral edge of the opening of the pocket 10. The grease that has entered the pocket 10 in this manner spreads over substantially the entire surface of the inner surface of the pocket 10 and the rolling surface of the ball 6 that face each other. In other words, the pocket 1
This almost completely fills the entire minute gap existing between the inner surface of the ball 0 and the rolling surface of the ball 6. As a result, when the ball 6 rolls, the grease generates resistance to the rolling of the ball 6 based on the shear resistance, and increases the dynamic torque.

In order to suppress an increase in dynamic torque due to such a cause, in order to reduce the amount of grease to be taken into the pocket 10, chamfers are formed on both the inner peripheral side and the outer peripheral side opening peripheral portion of the pocket 10. If the sharp edges of the peripheral edges of the openings are left, the frictional force acting between the inner surface of the pocket 10 and the rolling surface of the ball 6 increases, resulting in abnormal noise or vibration called retainer sound. Is more likely to occur.
On the other hand, although it is theoretically possible to adjust the amount of grease to be taken into the pocket 10 depending on the size of the chamfer, it is very difficult in practice, so a practical solution means I can not say. The cage for a rolling bearing and the rolling bearing of the present invention have been invented in view of such circumstances.

[0009]

SUMMARY OF THE INVENTION Among the cage for a rolling bearing and the rolling bearing according to the present invention, the cage for a rolling bearing according to the first aspect of the present invention is the conventional cage 8 shown in FIGS. In the same manner as described above, in order to hold a plurality of rolling elements rotatably, the whole is formed in an annular shape, and pockets are provided at a plurality of positions in the circumferential direction, each opening to the outside diameter side and the inside diameter side. In particular, in the rolling bearing retainer according to the first aspect, the outer peripheral side opening peripheral portion of each pocket is chamfered, and the inner peripheral side opening peripheral portion of each pocket is not chamfered.

[0010] Among the rolling bearing cage and the rolling bearing of the present invention, the rolling bearing according to the second aspect has an inner ring raceway formed on the outer peripheral surface, similarly to the rolling bearing 1 shown in FIG. An inner ring, an outer ring having an outer ring raceway formed on an inner peripheral surface thereof, and a rolling bearing retainer disposed between the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring so as to be rotatable relative to the inner ring and the outer ring; A ball is provided between the inner raceway and the outer raceway while being held in a freely rolling manner in a plurality of pockets provided in the rolling bearing retainer. In particular, in the rolling bearing described in claim 2, the rolling bearing retainer is the rolling bearing retainer described in claim 1.

[0011]

The rolling bearing retainer of the present invention configured as described above incorporates an appropriate amount of grease into a minute gap between the rolling surface of each rolling element and the inner surface of each pocket as follows. The dynamic torque of the rolling bearing of the present invention configured as described above can be reduced while preventing generation of harmful noise and vibration such as cage noise. That is, since the inner peripheral side opening peripheral edge of the inner peripheral side and the outer peripheral side opening peripheral part of each pocket is not chamfered, excessive grease is not taken into each pocket. For this reason, the rolling resistance based on the shearing force of the grease acting between the inner surface of each pocket and the rolling surface of each rolling element can be reduced, and the dynamic torque can be reduced. Further, since the outer peripheral edge of the outer periphery of each of the pockets is chamfered, the grease existing between the outer peripheral surface of the rolling bearing retainer and the inner peripheral surface of the outer ring in each of these pockets is efficiently removed. By taking in well, a grease film can be reliably interposed between the inner surface of each pocket and the rolling surface of each rolling element. For this reason, the frictional force of the rubbing portion between the inner surface of each pocket and the rolling surface of each rolling element can be suppressed to a small level, and the generation of abnormal noise or vibration called retainer sound can be effectively prevented.

Contrary to the case of the present invention, in the case where the inner peripheral edge of each pocket is chamfered and the outer peripheral edge of each pocket is not chamfered,
As described above, the excellent functions and effects obtained by the present invention cannot be obtained. That is, when the chamfered portion is reversed from the present invention, it becomes difficult to remove excess grease existing in the outer raceway provided on the inner peripheral surface of the outer race from this outer raceway,
Based on the agitation resistance of the grease on the outer raceway, not only the dynamic torque of the rolling bearing increases, but also the fluctuation of the dynamic torque becomes significant.

[0013]

1 to 3 show a first embodiment of the present invention. The feature of the present invention is that the cage 8
The positions of the chamfers 13 on the peripheral portions of the plurality of pockets 10 and 10 provided in the pocket a are devised so that the balls 6 and 6 (see FIGS. 6, 10 and 11) held in these pockets 10 and 10 are rolled. An appropriate amount of grease is taken into a minute gap between the moving surface and the inner surface of each of the pockets 10 and 10, and the dynamic torque of the rolling bearing 1 (see FIG. 6) is reduced by harmful noise and vibration such as cage noise. The point is to reduce the occurrence while preventing the occurrence. Since the configuration and operation of the other parts are the same as those of the above-described conventional structure, the illustration and description of the equivalent parts are omitted or simplified, and the following description will focus on the characteristic parts of the present invention.

Outer diametric side opening rims located on the outer peripheral surface side of the cage 8a among the inner and outer rims of the pockets 10 and 10 provided at equal intervals at a plurality of positions in the circumferential direction of the cage 8a. In the portion, a chamfer 13 is formed over the entire circumference except for a discontinuous portion of each of the elastic pieces 11 and 11. On the other hand, the inner peripheral surface of the retainer 8a, which is located on the inner peripheral surface side, is not chamfered, and the inner peripheral peripheral portion is formed with a sharp edge 14 having a large curvature (a small radius of curvature). And The cross-sectional shape of the chamfer 13 can be various shapes such as a straight line or an arc. As the synthetic resin constituting such a retainer 8a, various kinds of resins which have been conventionally used for producing the retainer can be used, and preferably, a polyamide resin, an oil-containing polyamide resin, a polyacetal resin, an oil-containing resin are used. Use a polyacetal resin or the like. Further, a reinforcing agent such as glass fiber, potassium titanate, or whisker may be added to these synthetic resins.

The retainer 8a of the present invention constructed as described above.
Is used in a state of being incorporated in the rolling bearing 1 as shown in, for example, FIG. When using the rolling bearing incorporating the cage 8a of the present invention, an appropriate amount of grease is applied to the minute gap between the rolling surface of each ball 6, 6 as a rolling element and the inner surface of each of the pockets 10, 10. By taking in, the dynamic torque of the rolling bearing incorporating the cage 8a can be reduced while preventing generation of harmful noise and vibration such as cage noise.

First of all, the inner peripheral side peripheral edge of the inner peripheral side and outer peripheral side opening peripheral edges of the pockets 10 and 10 is not chamfered, and the inner peripheral side opening peripheral edge is a sharp edge 14. Therefore, excessive grease is not taken into each of the pockets 10, 10. That is, the inner raceway 2 (see FIG. 6) on the outer peripheral surface of the inner race 3 on the inner diameter side of the inner peripheral surface of the retainer 8a.
Many of the grease adhering to the rolling surfaces of the balls 6, 6 from the above-described reference) is scraped off by the sharp edges 14 and does not enter the pockets 10, 10. For this reason, the rolling resistance based on the shearing force of the grease acting between the inner surface of each of the pockets 10 and the rolling surface of each of the balls 6, 6 is reduced, and the rolling with the retainer 8a is incorporated. The dynamic torque of the bearing can be reduced.

Further, since chamfers 13 are formed on the outer peripheral edge of the outer diameter side of each of the pockets 10, 10, the outer peripheral surface of the retainer 8a and the outer race 5 are provided in each of the pockets 10, 10.
The grease existing between the inner peripheral surface (see FIG. 6) and the inner peripheral surface can be efficiently taken in. Therefore, a grease film can be reliably interposed between the inner surfaces of the pockets 10 and the rolling surfaces of the balls 6. For this reason, the frictional force of the rubbing portion between the inner surface of each of the pockets 10, 10 and the rolling surface of each of the balls 6, 6 is suppressed to be small, and the generation of abnormal noise and vibration called retainer sound is effective. Can be prevented.

Next, FIGS. 4 and 5 show a second example of the embodiment of the present invention. In the case of the above-described first example, the chamfer 13 (see FIGS. 1 and 2) is performed over the entire periphery of the outer peripheral edge of the outer diameter side of each of the pockets 10 and 10. In the case of 8b, the chamfers 13a, 13a are formed only in a part of the outer peripheral edge of the opening of each pocket 10, 10. That is, the chamfers 13 are provided only on both circumferential ends of the outer peripheral edge of the pockets 10, 10.
a and 13a. The grease transferred from the outer raceway 4 on the inner peripheral surface of the outer race 5 to the rolling surfaces of the balls 6, 6 (see FIG. 6) remains on the rolling surfaces of the balls 6, 6 while the above-described chamfers 13 a, 13a. Therefore, each of the chamfers 13a, 13a is
Necessary and sufficient amount of grease can be taken in each of these pockets 10, 10 even if they are discontinuous at the bottom of 0, 10. The configuration and operation of the other parts are the same as in the case of the first example described above.

[0019]

As described above, the cage and the rolling bearing for a rolling bearing of the present invention are constructed and operated as described above. The torque can be reduced. For this reason, it is possible to improve the performance and save energy of various types of rotating equipment incorporating the rolling bearing.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first example of an embodiment of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 2;

FIG. 4 is a perspective view showing a second example of the embodiment of the present invention.

FIG. 5 is an enlarged view of a portion C in FIG. 4;

FIG. 6 is a sectional view showing an example of a rolling bearing incorporating a cage.

FIG. 7 is a half plan view showing a first example of a conventional structure of a cage.

FIG. 8 is a perspective view of the same.

FIG. 9 is a diagram illustrating a cross section taken along line DD of FIG.

FIG. 10 is a diagram showing a cross section taken along line EE of FIG. 9 in a state where a ball is incorporated.

FIG. 11 is a partial sectional view showing a second example of the conventional structure of the cage.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rolling bearing 2 Inner raceway 3 Inner raceway 4 Outer raceway 5 Outer raceway 6 Ball 7 Shield plate 8, 8a, 8b Cage 9 Main part 10 Pocket 11 Elastic piece 12 Concave part 13, 13a Chamfer 14 Sharp edge

Claims (2)

[Claims] In order to hold a plurality of rolling elements rotatably,
In a rolling bearing retainer having a whole formed in an annular shape and provided with pockets that open to the outer diameter side and the inner diameter side at a plurality of positions in the circumferential direction, the outer peripheral side opening peripheral edge of each of these pockets A cage for a rolling bearing, wherein chamfering is performed, and chamfering is not performed on an inner peripheral edge of each pocket. 2. An inner race having an inner raceway formed on an outer peripheral surface thereof, an outer race having an outer raceway formed on an inner peripheral surface thereof, and a relative position between the outer race surface of the inner race and the inner peripheral surface of the outer race with respect to the inner race and the outer race. A roller bearing retainer rotatably disposed, and disposed between the inner ring raceway and the outer ring raceway in a state in which each roller is rotatably held in a plurality of pockets provided in the roller bearing retainer. A rolling bearing comprising: a rolling element provided with the rolling element, wherein the cage for the rolling bearing is the cage for a rolling bearing according to claim 1.