JPH11325080A - Holder for radial ball bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of holder noise by a method wherein radial displacement of a holder to a ball is suppressed and a sufficient lubricant is inputted in a pocket. SOLUTION: A conical surface 18 on the outside diameter side and the rolling surface of a ball 5 are brought into contact with each other at the outside in the direction of a diameter from the pitch circle of the ball 5. A conical surface 19 on the inside diameter side and the rolling surface of the ball 5 are brought into contact with each other on the inside in the direction of a diameter in a similar manner described above. A distance between the inner surface of a pocket 8 and the rolling surface of the ball 5 is increased at a part deviated from the conical surfaces 18 and 19 on both the outer and inner diameter sides.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cage for a radial ball bearing, which relates to an improvement of a cage constituting a rolling bearing used in various rotary machines, and exists in a sliding contact portion between the cage and the ball. A sufficient amount of lubricant is secured to reduce the vibration and noise of the rolling bearing.

[0002]

2. Description of the Related Art As a ball bearing for supporting various rotating parts such as a bearing part of various rotating machine devices, for example, one having a structure as shown in FIG. 6 is widely used. This ball bearing comprises an inner race 2 having an inner race 1 on its outer peripheral surface and an outer race 3 on its inner peripheral surface.
And the outer ring 4 having a plurality of balls 5, 5 are provided concentrically with each other, and a plurality of balls 5, 5 are rotatably provided between the inner ring track 1 and the outer ring track 3. In the illustrated example, both the inner raceway 1 and the outer raceway 3 are of a deep groove type. The plurality of balls 5 are rollably held in pockets 8 provided in a holder 6.

[0003] The cage 6 constituting the ball bearing shown in FIG. 6 is called a corrugated press retainer. Each of the retainers 6 is formed by press-molding a metal plate material. It consists of a pair of elements 9,9. 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 abutted with each other at a portion deviating from the concave portions 8 a, 8 a,
These parts are connected and fixed by a plurality of rivets 10 to form a retainer 6 having an annular shape and having pockets 8 at a plurality of circumferential positions. The intermediate portion of the inner surface of each of the recesses 8a, 8a is a spherical holding concave surface 11 having a radius of curvature slightly larger than the radius of curvature of the outer surface of each of the balls 5,5. Therefore, when the pair of elements 9, 9 are abutted, the recesses 8 a, 8 a are combined to form pockets 8, 8.

A cage 6a called a crown-shaped cage shown in FIG. 7 is provided with balls 5, 5 (FIG. 6) at a plurality of circumferential positions of an annular main part 7 made of synthetic resin or the like. ) Are provided so that they can roll freely. In the case of such a crown-shaped retainer 6a, each of the pockets 8, 8 is provided on the main portion 7 with a pair of elastic pieces 1 spaced from each other.
2 and 12 and one side (upper surface in FIG. 7) of the main portion 7 in the axial direction (vertical direction in FIG. 7).
12 and spherical concave portions 13 and 13 provided in a portion between them. The radius of curvature of each of the concave portions 13 is slightly larger than the radius of curvature of the outer surface of the ball 5.

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 interval between the tip edges of 2, 12,
It is pushed between the pair of elastic pieces 12, 12. By holding the balls 5 and 5 in the pockets 8 and 8 in this manner, the retainer 6a connects the balls 5 and 5 to the inner raceway 1 and the outer raceway 3 (FIG. 6). In between, it is held so that it can roll freely.

The above-mentioned cage 6 or the above-mentioned cage 6a
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. The retainers 6 and 6a are
The balls 5 and 5 rotate around the inner ring 2 at the same speed as the revolution speed thereof.

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 a space between the outer peripheral surface of the inner ring 2 and the inner peripheral surface of the outer ring 4 are closed by a sealing member such as a seal plate or a shield plate, and lubricant may leak from this space. ,
Alternatively, foreign substances such as dust may be prevented from entering the space. However, FIG. 6 shows a ball bearing without such a sealing member.

[0008] In the case of a ball bearing incorporating the retainers 6 and 6a as described above, even if a required amount of lubricant is filled or supplied, vibrations are induced in the retainers 6 and 6a, and the retainers 6 and 6a are vibrated. Noise or vibration called retainer sound may be generated in the ball bearing incorporating 6a. Such a cage 6, 6
The vibration a is generated based on a collision or sliding friction between the balls 5, 5 and the retainers 6, 6a due to a large amount of movement of the retainers 6, 6a with respect to the balls 5, 5. That is, when the cages 6 and 6a are displaced in the radial direction with respect to the balls 5 and 5, the rolling surfaces of the balls 5 and 5 and the inner surfaces of the pockets 8 and 8 vigorously collide with each other, and In addition to generating sound,
The cage noise is also generated by the friction between the rolling surface and the inner surface. 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, simply reducing the amount of movement of the retainers 6, 6a with respect to the balls 5, 5 is due to the inner peripheral surface shape of the pockets 8, 8 of the retainers 6, 6a. Then, a retainer sound is generated. This reason will be described with reference to FIGS. As shown in FIGS. 8 to 9, sharp (greater curvature) corner portions 15, 15 are present at the opening peripheral portions 14, 14 of the pockets 8 of the retainers 6, 6 a. Is the resistance to the flow of the lubricant.

Therefore, the pocket 8 is required to suppress the retainer sound.
When the gap 16 between the inner surface of the ball 5 and the rolling surface of the ball 5 is reduced, the lubricant does not easily flow into the gap 16. That is, as the ball 5 rolls, the gap 16 is removed from the surrounding space.
The lubricant that is going to enter the inside of each corner 15, 15
And it is difficult to enter the gap 16. For this reason, a sufficient amount of the lubricant cannot be taken in the gap 16, and the frictional vibration of the sliding contact portion between the retainers 6, 6a and the balls 5, 5 cannot be sufficiently suppressed, and vibration and noise are induced. I do. The retainer for a radial ball bearing of the present invention includes:
The present invention has been made in view of such circumstances.

[0011]

The retainer for a radial ball bearing according to the present invention is, like the above-described conventional retainer for a radial ball bearing, entirely annular in order to hold a plurality of balls in a freely rolling manner. And pockets are provided at a plurality of positions in the circumferential direction. In particular, in the radial ball bearing retainer of the present invention, a part of the inner surface of each of the pockets, which is in contact with the rolling surface of the ball held in the pocket, is held in each of the pockets. The plurality of balls are positioned diametrically outside the pitch circle of the plurality of balls. At the same time, the remaining portion of the inner surface of each pocket is located on the opposite side of the first portion in the diametric direction of the pocket with respect to the first portion, and the second portion where the rolling surface of the ball held in the pocket is in contact, The plurality of balls held in each pocket are positioned diametrically inward from the pitch circle.

[0012]

The operation of the radial ball bearing retainer of the present invention configured as described above, when holding a plurality of balls in a freely rolling manner, is as follows.
This is the same as in the case of the conventional radial ball bearing retainer described above. In particular, in the case of the cage for a radial ball bearing of the present invention, the amount of movement of the cage with respect to the ball held in each pocket is suppressed, and the lubricant is inserted into the gap between the inner surface of the pocket and the rolling surface of the ball. Can be taken in as much as needed. For this reason, while preventing the rolling surface of the ball and the inner surface of the pocket from violently colliding with each other, improving the lubricity of the portion where these two surfaces rub against each other, preventing the generation of vibration and noise called retainer sound, and This contributes to a reduction in rotational torque and an improvement in durability of a radial ball bearing incorporating a retainer.

[0013]

1 and 2 show a first embodiment of the present invention. In this embodiment, the present invention is applied to the crown type retainer shown in FIG. The feature of the present invention is that the rolling of the ball 5 and the inner surface of the pocket 8 is suppressed while suppressing the radial displacement of the cage 6 b with respect to the ball 5, in other words, while suppressing the radial displacement of the ball 5 in the pocket 8. The inner shape of the pocket 8 is devised so that a lubricant such as grease can be sufficiently taken in the gap 16 between the pocket and the surface (see FIGS. 8 and 9). Since the configuration and operation of the other parts are the same as in the above-described conventional technology,
The illustration and description of the equivalent parts are omitted or simplified, and the following description focuses on the features of the present invention.

An inner surface of the pocket 8 provided on one surface in the axial direction of the annular main portion 7 has a cylindrical surface 17 at the center of the retainer 6b in the diameter direction (vertical direction in FIG. 2). And
An outer diameter side conical surface 18 is formed in a part of the pocket 8 in the circumferential direction at a portion diametrically outside the cylindrical surface 17. The outer diameter side conical surface 18 is connected to the retainer 6.
b is a conical concave surface in which the diameter becomes smaller toward the outside in the diameter direction. A part of the rolling surface of the ball 5 rotatably held in the pocket 8 contacts a part of the outer diameter side conical surface 18. The contact portion between the rolling surface and the outer diameter side conical surface 18, which is the first portion described in the claims, is a pitch of the plurality of balls 5 held in the plurality of pockets 8 provided in the retainer 6b. It is located diametrically outside the circle a. or,
Of the inner surface of the pocket 8, the remaining portion of the outer portion in the diameter direction from the cylindrical surface 17, that is, the inner diameter of the portion of the retainer 6 b outside the cylindrical surface 17 that deviates from the outer diameter conical surface 18. Is larger than the diameter of the cylindrical surface 17 so that the remaining portion and the rolling surface of the ball 5 are sufficiently separated.

On the other hand, at a portion in the diameter direction inside of the cylindrical surface 17, the remaining portion of the pocket 8 in the circumferential direction is substantially opposite to the outer diameter side conical surface 18 in the diameter direction of the pocket 8. An inner diameter side conical surface 19 is formed in the portion. The inner diameter side conical surface 19 is a conical concave surface whose diameter decreases toward the inside in the diameter direction of the retainer 6b. A part of the rolling surface of the ball 5 rotatably held in the pocket 8 comes into contact with a part of the inner diameter side conical surface 19. The contact portion between the rolling surface and the inner diameter side conical surface 19, which is the second portion described in the claims, is provided in the cage 6b.
Balls 5 held in a plurality of pockets 8 provided in
Is located diametrically inward of the pitch circle a. Also, of the inner surface of the pocket 8, the remaining portion of the inner side in the diametrical direction from the cylindrical surface 17, that is, the retainer 6 b
The inner diameter of the portion of the inner diameter side deviated from the inner diameter side conical surface 19 is larger than the diameter of the cylindrical surface 17 so that the remaining portion and the rolling surface of the ball 5 are sufficiently separated. .

In the case of the cage for a radial ball bearing of the present invention configured as described above, the amount of movement of the cage 6b with respect to the ball 5 held in each pocket 8 having the inner surface shape as described above is determined. In addition, it is possible to take in a necessary amount of the lubricant into the gap between the inner surface of each pocket 8 and the rolling surface of the ball 5. That is, the plurality of balls 5 rotatably held by the cage 6b are
However, displacement inward in the diameter direction is prevented based on the engagement between the outer diameter side conical surface 18 and the rolling surface of each of the balls 5. On the contrary, for each of these balls 5, the retainer 6b is
Displacement to the outside in the diametrical direction is caused by the above-mentioned inner side conical surface 19.
And the ball 5 engages with the rolling surface.

Furthermore, in order to minimize the radial displacement of the retainer 6b with respect to each of the balls 5, the outer and inner conical surfaces 18 and 19 and the rolling surface of each of the balls 5 are formed. Even if they are close to each other, the area of the opening for taking in the lubricant can be secured. That is, the outer diameter side and the inner diameter side conical surfaces 18 are provided between the peripheral edges of both ends of the pockets 8 and the rolling surfaces of the balls 5 in the inner and outer peripheral surfaces of the retainer 6b. , 19 are largely open at the portions outside. Therefore, as described above, the displacement of the retainer 6b in the radial direction with respect to each ball 5 can be slightly suppressed, and the area of the opening for taking in the lubricant can be secured. Thus, the rolling surface of each ball 5 and the inner surface of the pocket 8 are prevented from violently colliding with each other, and the lubricating properties of a portion where these two surfaces rub against each other are improved, so that vibration and noise called retainer sound are generated. Prevention of occurrence, and cage 6b
The reduction of the rotational torque and the improvement of the durability of a radial ball bearing incorporating the same can be achieved.

Next, FIGS. 3 and 4 show a second example of the embodiment of the present invention. In the case of this example, an outer-diameter-side spherical surface 20 is formed on the inner surface of the pocket 8 in the diametrically outer portion of the retainer 6c than the cylindrical surface 17, and an inner-diameter-side spherical surface 21 is formed on the same diametrically inner portion. ing. Each of the outer and inner spherical surfaces 20 and 21 is a spherical concave surface having a slightly larger radius of curvature than the radius of curvature of the rolling surface of the ball 5. In the case of such a structure of the present example, the retainer 6c has a diameter relative to the ball 5 based on the engagement between the outer and inner spherical surfaces 20, 21 and the rolling surface of the ball 5. Prevent displacement in the direction. Other configurations and operations are the same as those of the above-described first example.

In practicing the present invention, the portion corresponding to the first portion and the portion corresponding to the second portion described in the claims can be divided into the inside and outside of the pitch circle of the ball. For example, the shape of each part is not limited to the illustrated example, such as combining the shapes of the first and second examples, and various changes can be made. Further, the guide of the retainer may be a rolling element guide or a raceway guide. Further, by taking a chamfer or forming a convex curved surface having an arc-shaped cross section at the periphery of the opening of the pocket, the lubricant can be more efficiently taken into the pocket.

[0020]

EXAMPLE Next, an experiment conducted by the present inventor to confirm the effect of the present invention will be described. In the experiment, a radial ball bearing incorporating a cage belonging to the present invention and a radial ball bearing incorporating a cage belonging to a conventional structure were prepared.
Rotating the inner ring while fixing the outer ring of these two ball bearings,
This was performed by measuring the torque required for the rotation.
As a cage belonging to the present invention, a cage provided with a pocket 8 having a shape as shown in FIGS. 1 and 2 is used. As a cage belonging to the conventional structure, as shown in FIG. Each having a concave pocket was prepared. Further, as a material of the retainer, a material made of fiber reinforced plastic in which glass fiber was mixed in polyamide 66 at 10% by volume was used. The retainer used had an inner diameter of 6.7 mm, an outer diameter of 8.7 mm, and a height in the axial direction of 1.73 mm. As a radial ball bearing incorporating such a retainer, a miniature bearing having an identification number of MR115B (inner diameter is 5 mm, outer diameter is 11 mm and width is 4 mm)
It was used. For lubrication, an ester-based antirust lubricating oil was applied by oil plating. The conditions other than the inner shape of the pocket 8 were all the same.

As described above, two types of radial ball bearings in which only the inner shape of the pocket of the cage is changed are assembled to the electric motor, and 5400 kgf is applied under a preload of 1.5 kgf.
When the inner ring was rotated at rpm and the noise generated with the rotation was measured, the results shown in FIG. 5 were obtained. The solid line α shown in FIG. 5 indicates the noise level of the radial ball bearing incorporating the cage according to the present invention, similarly to the broken line β.
Indicates the noise level of a radial ball bearing incorporating a cage belonging to the conventional structure. As is clear from the description of FIG. 5 showing the results of such an experiment, in the case of the radial ball bearing incorporating the cage of the present invention, the noise characteristics particularly in a harsh high-frequency range are improved.

[0022]

The cage for a radial ball bearing according to the present invention is constructed and operates as described above, so that various kinds of equipment incorporating the radial ball bearing with reduced noise while suppressing generation of cage noise. Can contribute to the performance improvement.

[Brief description of the drawings]

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

FIG. 2 is a view taken in the direction of arrow A in FIG. 1;

FIG. 3 is a partially enlarged perspective view of a retainer, showing a second example of the embodiment of the present invention.

FIG. 4 is a view taken in the direction of arrow B in FIG. 3;

FIG. 5 is a diagram showing the results of an experiment performed to confirm the effects of the present invention.

FIG. 6 is a partially cutaway perspective view showing an example of a ball bearing incorporating a conventionally known cage.

FIG. 7 is a perspective view showing another example of a conventionally known cage.

FIG. 8 is an enlarged cross-sectional view showing a state where a ball is held by the cage shown in FIG. 6;

FIG. 9 is an enlarged cross-sectional view showing a state where a ball is held in the cage shown in FIG. 7;

[Explanation of symbols]

 Reference Signs List 1 inner ring track 2 inner ring 3 outer ring track 4 outer ring 5 ball 6, 6a, 6b, 6c retainer 7 main portion 8 pocket 8a concave portion 9 element 10 rivet 11 retaining concave surface 12 elastic piece 13 concave surface portion 14 opening peripheral edge 15 corner 16 gap 17 cylindrical surface 18 outer diameter side cone surface 19 inner diameter side cone surface 20 outer diameter side spherical surface 21 inner diameter side spherical surface

Claims (1)

[Claims] An inner surface of each pocket in a radial ball bearing retainer having a plurality of balls formed so as to be able to roll freely and having pockets at a plurality of positions in a circumferential direction. A part of the first portion that is in contact with the rolling surface of the ball held in the pocket is positioned diametrically outside the pitch circle of the plurality of balls held in each pocket, and The remaining portion of the inner surface of the pocket, which is located substantially opposite to the first portion in the diametrical direction of the pocket with respect to the first portion and is in contact with the rolling surface of the ball held in the pocket, is retained in each of the pockets. A radial ball bearing retainer, wherein the retainer is positioned radially inward of a pitch circle of a plurality of balls.