JPH09303402A - Retainer for ball bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain the sounding of a retainer sound and reduce the vibration and noise of a ball bearing. SOLUTION: A retainer 6a has annularity, and is equipped with pockets 8 on plural places in a circumferencial direction. The inner surface of the pocket 8 is constituted of a cylindrical surface, and a thread 15, formed on the end part of the cylindrical surface 14 to be protruded to the ciameter direction inner part of the pocket 8. Consequently, a frictional characteristic, between the rolling surface of a ball 5 and the inner surface of the pocket 8 can be improved, and also lubricant can be easily fed between both these mating surfaces. Also, the engagement, between the thread 15 and the rolling surface of the ball, limits the displacement of the retainer 6a, to restrain the sounding of the sound of the retainer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The cage for ball bearings of the present invention relates to an improvement of a cage which constitutes a ball bearing used in various rotary machinery, and lubricates a sliding contact portion between the cage and the balls sufficiently. To reduce the vibration and noise of the ball bearing.

[0002]

2. Description of the Related Art For example, a ball bearing as shown in FIG. 14 is widely used as a ball bearing for supporting various rotating parts such as bearings of various rotary machines. In this ball bearing, an inner ring 2 having an inner ring raceway 1 on an outer peripheral surface and an outer ring 4 having an outer ring raceway 3 on an inner peripheral surface are concentrically arranged, and a plurality of ball races are provided between the inner ring raceway 1 and the outer ring raceway 3. 5 and 5 are provided so as to be rollable. In the illustrated example, both the inner ring raceway 1 and the outer ring raceway 3 are deep groove type. In addition, the plurality of balls 5, 5
Are rotatably held in pockets 8 provided in the holder 6.

The cage 6 constituting the ball bearing shown in FIG. 14 is called a corrugated press cage, and each cage 6 is formed in a corrugated annular shape, which is obtained by press-molding a metal plate material. A pair of elements 9, 9 are combined. These two elements 9, 9 have recesses 8a, 8a for forming the pockets 8, 8 at a plurality of positions in the circumferential direction, respectively. Then, the pair of elements 9, 9 are butted at portions deviating from the concave portions 8 a, 8 a, and these portions are connected and fixed by a plurality of rivets 10, and the pockets 8 are formed at a plurality of positions in the annular direction in the circumferential direction. 8 as a retainer 6. The middle part of the inner surface of each of the recesses 8a, 8a
The spherical concave surface having an arcuate cross section has a radius of curvature slightly larger than the radius of curvature of the outer surface of each of the balls 5, 5. For this reason, when the pair of elements 9 and 9 are abutted against each other,
a and 8a are combined to form pockets 8 and 8.
A holding concave surface 11 having a radius of curvature slightly larger than the radius of curvature of the rolling surface of the balls 5 and 5 is provided as a holding surface in the middle portion of the inner surface of each of the pockets 8 and 8.

Further, a cage 6a called a crown type cage shown in FIG. 15 has balls 5, 5 (see FIG. 14) at a plurality of circumferential positions of an annular main portion 7 made of synthetic resin or the like. (See FIG. 3) is provided so as to be rollably held. In the case of such a crown-shaped cage 6a, the pockets 8 and 8 are
On one side surface of the pair of elastic pieces 12, 12 arranged at a distance from each other on the main portion 7 and on one side (upper surface in FIG. 15) in the axial direction (vertical direction in FIG. 15) of the main portion 7. A spherical concave surface portion 1 provided between the pair of elastic pieces 12, 12.
It is composed of 3 and 13. The radius of curvature of the concave portions 13, 13 is slightly larger than the radius of curvature of the rolling surface of the ball 5. One side surface of each of these elastic pieces 12, 12 and the concave surface portion 1
3, 3 and 13 form a holding concave surface.

When assembling the ball bearing, each of the balls 5,
5 is a pair of elastic pieces 1 forming each pocket 8, 8.
While elastically expanding the gap between the tip edges of 2 and 12,
It is pushed between the pair of elastic pieces 12, 12. The cage 6a holds the balls 5 and 5 in the pockets 8 and 8 in this manner, and thereby the balls 5 and 5 are transferred to the inner ring raceway 1 and the outer ring raceway 3 (see FIG. 14). Hold between them while rolling.

The retainer 6 described above or the retainer 6a described above
When the ball bearing provided with is used, the relative rotation between the inner ring 2 and the outer ring 4 is made free with the rolling of the plurality of balls 5. At this time, the plurality of balls 5, 5 revolve around the inner ring 2 while rotating. In addition, both cages 6 and 6a
Is the same as the revolution speed of the balls 5 and 5, and is the inner ring 2
Rotate around.

A portion between the outer peripheral surface of the inner race 2 and the inner peripheral surface of the outer race 4 is filled or continuously supplied with a lubricant such as grease or other lubricating oil, so that the relative rotation is smoothly performed. Like In addition, vibration and noise are not generated in the ball bearing, and failures such as burn-in are prevented. still,
In some ball bearings, both ends of the space between the outer peripheral surface of the inner race 2 and the inner peripheral surface of the outer race 4 are closed by a sealing member such as a seal plate or a shield plate, and the lubricant leaks from this space. In some cases, foreign substances such as dust are prevented from entering this space. However, FIG. 14 shows a ball bearing without such a sealing member.

In the case of the ball bearing in which the cages 6 and 6a as described above are incorporated, vibration is induced in the cages 6 and 6a even if the required amount of lubricant is filled or supplied, and the cages 6 and 6a are Noise or vibration called cage noise may occur in the ball bearing in which 6a is incorporated. Such a retainer 6, 6
The vibration of a is generated due to the sliding friction between the balls 5 and 5 and the retainers 6 and 6a due to the large movement amount of the retainers 6 and 6a with respect to the balls 5 and 5. Conventionally, in order to suppress the generation of such retainer sounds, the gap between the inner surfaces of the pockets 8 and 8 and the rolling surfaces of the balls 5 and 5 has been reduced so that the retainers 6 and 6a In this case, the amount of movement of the cage is reduced to suppress the occurrence of cage sound.

[0009]

However, if the amount of movement of the cages 6, 6a relative to the balls 5, 5 is simply reduced, the cages 6, 6a will be retained due to the inner surface shape of the pockets 8, 8 of the cages 6, 6a. Instrumental sound is generated. That is, FIGS.
In the case of the conventional structure shown in (1), since the inner surface shape of the pockets 8, 8 is a spherical concave surface, the friction area between this inner surface and the rolling surfaces of the balls 5, 5 is wide. In particular, if the difference between the radius of curvature of the inner surface and the radius of curvature of the rolling surface is reduced in order to reduce the amount of movement, the friction area is widened, and vibration based on sliding friction between these inner surface and rolling surface is generated. It tends to occur. The cage for ball bearings of the present invention, in order to eliminate such inconvenience,
Decrease the amount of movement of cages 6 and 6a relative to balls 5 and 5,
Moreover, it is intended to prevent the occurrence of frictional vibration by narrowing the friction area between the inner surface and the rolling surface.

[0010]

The ball bearing cage according to the present invention is formed in an annular shape as a whole in order to hold a plurality of balls in a rollable manner, like the conventional ball bearing cage described above. However, pockets are provided at a plurality of positions in the circumferential direction. Particularly, in the ball bearing cage according to the present invention, the inner surface of each pocket is
A cylindrical surface and a ridge having an arcuate cross section which is formed at least at one axial end of the cylindrical surface in the circumferential direction of the cylindrical surface and projects inward in the diametrical direction of the cylindrical surface.

[0011]

The ball bearing cage according to the present invention having the above-described structure has the same function as that of the ball bearing cage in which it is rollably held, as in the case of the conventional ball bearing cage described above. is there. In particular, in the case of the cage for ball bearings of the present invention, the amount of movement of the cage with respect to the balls can be reduced and the friction area between the inner surface of the pocket and the rolling surface can be narrowed to prevent the occurrence of frictional vibration. . That is, the amount of movement of the cage with respect to the balls can be limited by the engagement between the protrusion and the balls. Therefore, by restricting the position where the ridge is formed on the inner surface of each pocket, it is possible to suppress the above-mentioned amount of movement and suppress the generation of cage noise that accompanies radial displacement of the cage. Further, since the inner surface of each pocket is formed by the cylindrical surface and the ridge, the contact area between the rolling surface of the ball rotatably held in each pocket and the inner surface of the pocket can be narrowed. . Therefore, it is possible to suppress the generation of cage noise due to the friction between the inner surface and the rolling surface. Moreover, since there is a large gap between the inner surface and the rolling surface, the lubricant is likely to be taken into the gap between the inner surface of the pocket and the rolling surface of the ball, and the lubrication of the sliding contact portion is facilitated. The condition will be good. That is, in the case of the ball bearing cage according to the present invention, the contact state between the inner surface of each pocket and the rolling surface is closer to line contact or point contact than surface contact, and sufficient lubrication is applied to the contact portion. Since the agent is supplied, sliding friction between the inner surface and the rolling surface is reduced. As a result, vibrations and noise called cage sound are less likely to occur.

[0012]

1 and 2 show a first embodiment of the present invention. In the illustrated example, the present invention is applied to a crown type cage. In the case of this example, FIG.
The cage sound is reduced by changing the inner surface shape of the pockets 8 of the crown-shaped cage 6a having the overall shape as shown in FIG. That is, in the case of this example, the inner surface of each of the pockets 8 and 8 constituting the cage 6a is the cylindrical surface 14 and the one axial end of the cylindrical surface 14 is the outside of each of the pockets 8 and 8. The ridge 15 provided on the peripheral edge of the opening on the radial side (the outer peripheral side of the cage 6a). Of these, the central axis of the cylindrical surface 14 exists in the diametrical direction of the main body of the cage 6a. The projection 15 has an arcuate cross section, is formed in the circumferential direction of the cylindrical surface 14, and projects inward in the diametrical direction of the cylindrical surface 14.

The inner diameter of the cylindrical surface 14 is equal to the pocket 8
It is slightly larger than the outer diameter of the ball 5 which is to be rotatably held inside. Further, in a state where the balls 5 are rotatably held between the inner ring raceway 1 on the outer circumferential surface of the inner ring 2 and the outer ring raceway 3 on the inner circumferential surface of the outer ring 4 (the state assembled as shown in FIG. 14), The rolling surface of the ball 5 and the ridge 15 face each other through a sliding contact or a minute gap.

The operation itself when the cage for ball bearings of the present invention configured as described above holds the plurality of balls 5 in a rollable manner is the same as that of the conventional ball bearing shown in FIG. It is similar to the case of the cage. Particularly, in the case of the ball bearing cage of the present invention, the amount of movement of the cage 6a with respect to the ball 5 is reduced, and moreover, the friction area between the inner surface of each of the pockets 8 and 8 and the rolling surface of the ball 5 is reduced. By making it narrower, the occurrence of frictional vibration can be prevented.

That is, the amount of movement of the cage 6a with respect to the balls 5 can be limited by the engagement between the projections 15 of the pockets 8 and the rolling surfaces of the balls 5. Therefore, each of the above pockets 8,
By restricting the formation position of the protrusions 8 on the inner surface of 8, it is possible to suppress the above-mentioned amount of movement and suppress the generation of a cage sound due to the cage 6a being displaced in the radial direction. . In addition, the inner surface of each of the pockets 8 and 8 is replaced by a cylindrical surface 14
And the ridges 15, the pockets 8 and
It is possible to reduce the contact area between the rolling surfaces of the balls 5 and 5 rotatably held in the pockets 8 and the inner surfaces of the pockets 8 and 8. Therefore, it is possible to suppress the generation of cage noise due to the friction between the inner surface and the rolling surface. Moreover, between the inner surface and the rolling surface,
As shown in FIG. 2, since a large gap 16 is present, a lubricant such as grease is easily taken into the gap 16 between the inner surface of each pocket 8 and the rolling surface of the ball 5, and the sliding contact portion The lubrication condition is good.

That is, in the case of the cage for ball bearings of the present invention, the contact state between the inner surface of each pocket 8 and the rolling surface of the ball 5 is closer to line contact or point contact than surface contact. Moreover, sufficient lubricant is supplied to the contact portion. Therefore, sliding friction between these inner surface and rolling surface is reduced. As a result, vibrations and noise called cage sound are less likely to occur.

As described above, since the friction characteristics and the lubrication characteristics of the sliding contact portion between the inner surface of the pocket 8 of the cage 6a and the rolling surface of the ball 5 are improved, the cage 6a of this example is used. Vibration and noise are less likely to occur in the ball bearing. In order to confirm the effect of the present invention, the inventor of the present invention produces noise caused by the ball bearing using the conventional cage shown in FIG. 15 and the ball bearing using the cage according to the present invention. Experiments were performed to measure and compare the frequency spectra of the. The ball bearings used in the experiment had an outer ring outer diameter of 35 mm, the same width of 11 mm, an inner ring inner diameter of 15 mm, a ball diameter of 6 mm, and eight balls.

The results of the experiment conducted under such conditions are
The frequency spectrum of each ball bearing is shown in FIG. In this figure, the horizontal axis represents frequency and the vertical axis represents noise level. Of the two lines representing the measurement results, the chain line a represents the frequency spectrum of the noise generated by the ball bearing constructed using the cage according to the present invention, and the solid line b represents the conventional cage. The frequency spectrum of the noise generated by the constructed ball bearing is shown.
Among the constituent parts constituting each of these ball bearings, the same (equivalent) parts were used for the constituent parts other than the cage. As can be seen from FIG. 3, in the case of the ball bearing using the cage according to the present invention, the peak of the frequency spectrum is small. In the process of this experiment, as a result of performing the same experiment by changing the radius of curvature of the cross-sectional shape of the ridge 15, the radius of curvature should be 2% or more of the outer diameter of the ball 5. It has been found that it is preferable in terms of enhancing the effect of reducing instrumental noise.

Next, FIGS. 4 to 5 show a second example of the embodiment of the present invention. In the case of the first example described above, the ridge 15 is formed on the outer peripheral edge portion of the inner surface of the pocket 8, whereas in the present example, the inner peripheral surface opening of the inner surface of the pocket 8 is formed. The ridge 15 is formed on the peripheral portion. Other configurations and operations are similar to those of the above-described first example.

Next, FIGS. 6 to 7 show a third example of the embodiment of the present invention. In the case of this example, the protrusions 15 are formed on the inner peripheral surface of the pocket 8 on both the inner diameter side and the outer diameter side. Other configurations and operations are the same as those of the first embodiment described above.
This is similar to the case of the example and the second example described above.

Next, FIGS. 8 to 9 show a fourth example of the embodiment of the present invention. In the case of this example, the protrusions 15a, 15a are provided on the outer peripheral edge portion of the inner surface of each pocket 8 except for the circumferential intermediate portion. Other configurations and operations are the same as in the case of the above-described first example.

Next, FIGS. 10 to 11 show a fifth example of the embodiment of the present invention. In the case of this example, pocket 8
Protrusions 15a, 15a are provided on the inner peripheral surface of the inner surface of the inner peripheral surface of the inner peripheral surface of the inner peripheral surface of the inner peripheral surface of the inner peripheral surface of the inner peripheral surface of the inner peripheral surface of the inner peripheral surface of the inner peripheral surface of the inner peripheral surface of the inner peripheral surface of the inner peripheral surface of the inner peripheral surface. Other configurations and operations are the same as in the case of the above-described first example.

Next, FIGS. 12 to 13 show a sixth example of the embodiment of the present invention. In the case of this example, pocket 8
A pair of ridges 15a, 15a is formed on the inner peripheral surface of the inner surface of the inner peripheral surface of the inner peripheral surface of the outer peripheral surface of the outer peripheral surface of the outer peripheral surface of the inner peripheral surface of the inner peripheral surface of the inner peripheral surface of the inner peripheral surface of the inner peripheral surface. Other configurations and actions are similar to those of the above-described fourth example and the above-described fifth example.

[0024]

Since the cage for ball bearings of the present invention is constructed and operates as described above, the frictional state and lubrication of the sliding contact portion between the rolling surface of the ball and the inner surface of the pocket formed in the cage. The condition will be good. As a result, in the ball bearing configured by using the ball bearing cage according to the present invention, generation of cage noise is suppressed, and a ball bearing with low vibration and low noise can be obtained. Further, in the case of the cage for ball bearings of the present invention, the friction at the sliding contact portion between the rolling surface of the balls and the inner surface of the pocket formed in the cage is reduced, so that the wear resistance of the cage can be improved.

[Brief description of drawings]

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

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a diagram showing the results of an experiment performed to confirm the effects of the present invention.

FIG. 4 is an enlarged perspective view showing a part of the cage showing the second example of the embodiment of the invention.

FIG. 5 is a sectional view taken along line BB of FIG. 4;

FIG. 6 is an enlarged perspective view showing a part of the cage showing the third example of the embodiment of the invention.

7 is a sectional view taken along line CC of FIG.

FIG. 8 is an enlarged perspective view showing a part of the cage, showing a fourth example of the embodiment of the invention.

9 is a cross-sectional view taken along line DD of FIG.

FIG. 10 is an enlarged perspective view showing a part of the cage showing the fifth example of the embodiment of the invention.

11 is a sectional view taken along line EE of FIG.

FIG. 12 is an enlarged perspective view showing a part of the cage, showing a sixth example of the embodiment of the invention.

13 is a sectional view taken along line FF of FIG.

FIG. 14 is a partially cutaway perspective view showing an example of a conventionally known ball bearing.

FIG. 15 is a perspective view showing another example of a conventionally known cage.

[Explanation of symbols]

 1 Inner ring track 2 Inner ring 3 Outer ring track 4 Outer ring 5 Balls 6, 6a Cage 7 Main part 8 Pocket 8a Recess 9 Element 10 Rivet 11 Holding concave 12 Elastic piece 13 Concave 14 Cylindrical 15 15a Projection 16 Gap

Claims (1)

[Claims] 1. A cage for a ball bearing, which is formed in an annular shape as a whole in order to hold a plurality of balls in a rollable manner and has pockets provided at a plurality of positions in the circumferential direction. The inner surface includes a cylindrical surface and a ridge having an arc-shaped cross section, which is formed at least at one axial end of the cylindrical surface in the circumferential direction of the cylindrical surface and projects inward in the diametrical direction of the cylindrical surface. A cage for ball bearings characterized by having