JPH09151943A - Resin holder for ball bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform the integration of a hard resin material into a bearing without reducing the working property even with nor generating an unreasonable stress. SOLUTION: A crown-shaped holder having claws 3 on both sides of a pocket 4, each claw 3 has a slit 5 on pitch circle PCD. Instead of providing the slit 5, each part between pockets 4, 4 is largely notched on the side surface opposite to the claw 3 of an annular body 1. The claw 3 may be shortened so that the inlet part dimension between the claws 3 is minimized as much as possible within a range less than a ball diameter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin retainer for ball bearings having an improved assembling property.

[0002]

2. Description of the Related Art Generally, a flexible material such as nylon (PA66) is used as a material for a resin retainer, but with the expansion of specifications, heat resistance such as polyphenylene sulfide resin (PPS resin) is used.・ High-strength materials have also been used. As a shape of the resin retainer for ball bearings, a shape called a one-piece crown shape is generally used due to advantages of a molding die and assembling property.

FIG. 4 shows an example of a conventional crown-shaped resin holder for ball bearings. This cage has a plurality of recesses 52 in which a part of balls are fitted in a plurality of circumferential positions on one side surface of an annular body 51.
A pocket 54 for holding a ball is formed by a pair of claws 53 protruding on both sides of the recess 52. On the side surface of the annular body 51 opposite to the claw 53, a recess 55 for reducing the weight is provided between the pockets 54. The recessed portion 55 is provided at the center of the thickness of the cage, whereby the formation portion of the pocket 54 is connected by the two wall portions 56 on the inner diameter side and the outer diameter side to secure the strength of the cage and to secure the strength of the cage. It is designed to promote uniform resin flow. When the bearing is assembled, the cage is pushed in from the side surface of the bearing (direction of arrow A in FIG. 4B). At this time, when the pair of ball-holding claws 53, which are evenly arranged in the cage, temporarily expand and the cage enters a predetermined position between the inner and outer races, the ball fits in the pocket 54.

[0004]

However, if the flexibility of the material itself decreases as the strength of the material increases as described above, a pulling force acts on the bottom of the pocket 54 when the claw 53 expands, and the claw 53 opens. It's difficult to get a ball in.
As a general measure, a method of incorporating the cage in a slightly softened state by warming it can be considered, but it takes a lot of assembly man-hours and the workability is deteriorated.

An object of the present invention is to provide a resin retainer for a ball bearing which can be incorporated into a bearing without deteriorating workability and generating unreasonable stress even with a hard resin material. is there.

[0006]

According to a first aspect of the present invention, there is provided a resin retainer for a ball bearing, which has a recess in which a part of a ball fits at a plurality of circumferential positions on one side surface of an annular body, and the recess. 1. A crown-shaped cage in which a pocket for holding a ball, which is composed of a pair of claws protruding on both sides, is formed, and each claw is provided with a slit along the axial direction. By providing the slits in this way, the claws have flexibility, and the pulling force at the bottom of the pocket at the time of bearing assembly is reduced. That is, when the cage is installed in the bearing, the balls move to try to fit in the recess. At this time, if the claw is provided with the slit as described above, the pulling force at the bottom of the retainer is alleviated.

A ball bearing resin retainer according to a second aspect of the present invention is an annular ball bearing resin retainer in which pocket forming walls for holding balls and connecting pieces are alternately formed. The wall is formed in a C shape having openings on one width surface and the inner peripheral surface and the outer peripheral surface, and the connecting piece has a thickness for connecting only the vicinity of the pitch circle of the ball held in the pocket forming wall. It is a thing. In this way, by making the connecting piece the minimum thickness for connecting only the vicinity of the pitch circle, the flexibility of the cage is enhanced, and the generation of unreasonable stress when assembled in the bearing is prevented. In the resin retainer for ball bearings according to claim 3 of the present invention, pockets each having a concave portion into which a ball is fitted are provided at a plurality of circumferential positions on one side surface of the annular body, and the opening size of the inlet portion of each pocket is set to the ball. The size is slightly smaller than the diameter. It is preferable that the opening size is closer to the ball diameter within a smaller range of the ball diameter. The annular body may be provided with short claws on both sides of the pocket. As described above, by reducing the range of holding the ball by the retainer, the assembling force is reduced and the stress at the time of assembling is reduced.

[0008]

FIG. 1 shows a first embodiment of the present invention.
It will be described based on. This ball bearing resin retainer includes a recess 2 into which a part of a ball is fitted at a plurality of circumferential positions on one side surface of an annular body 1, and a pair of claws 3 protruding on both sides of the recess 2.
In the cage having the pockets 4 for holding the ball, the slits 5 are provided in each claw along the axial direction. The slit 5 is provided over the entire height of the claw 3 on the pitch circle PCD and divides the claw 3 in two. The inner surface of the recess 2 and the inner surface of the claw 3 are continuous spherical surfaces. Ring 1
On the side surface opposite to the claws 3, a concave portion 6 in the shape of a circular arc groove is provided in the portion between the pockets 4 for weight reduction. This cage is an integrally molded product, and is made of a resin material harder than nylon (PA66), for example, polyphenylene sulfide resin (PPS resin).

According to this structure, since the slits 5 are provided in the claws 3 to divide each claw 3 into two, the claws 3 are given flexibility and the assembling force is reduced. That is, the movement of the cage during the assembly of the bearing alleviates the tensile force generated at the bottom of the pocket 4. Therefore, even if it is made of a hard resin, it can be assembled at room temperature without causing whitening or cracks at the bottom of the pocket during assembly.

FIG. 2 shows a second embodiment of the present invention.
This example is an annular resin holder for ball bearings in which pocket forming walls 7 for holding balls and connecting pieces 8 are alternately formed, and each pocket forming wall 7 has one width surface and one inner diameter side and one outer diameter side. It is formed in a C-shape that is open to the peripheral surface and the connecting piece 8 has a thickness that connects only the pitch circle of the ball held in the pocket forming wall 7. In other words, in the embodiment of FIG. 1, the portion between the pockets 3 on the side opposite to the claws 3 of the annular body 1 is notched over the entire width. A portion of the pocket forming wall 7 that is closer to the tip than the connecting piece 8 corresponds to the claw 3 in the example of FIG. 1. In this embodiment, the slit 5 is not formed in the portion corresponding to the claw 3, but the slit 5 may be formed in the claw 3 as in the example of FIG. The material of the cage is the same as in the example of FIG. In the case of this configuration, since the connecting piece 8 has the minimum thickness as the thickness for connecting only the vicinity of the pitch circle, the flexibility of the retainer is enhanced, and the generation of unreasonable stress when assembled in the bearing is prevented. . This example corresponds to a shape in which the two wall portions 56 connecting the peripheral portions of the pockets in the conventional example of FIG. 4 are eliminated, but the conventional example of FIG. 4 has a structure in which the two wall portions 56 are connected. Is based on a flexible material, and in the case of a material having high strength, it is not necessary to connect the two wall portions 56 as in the example of FIG. In this embodiment, by omitting such unnecessary portions, the thickness of the bottom portion of the pocket 4 is made uniform and the pulling force generated during assembly is dispersed. That is, the bottom of the pocket is more flexible than the example of FIG. 4, and whitening and cracks are prevented even when assembled at room temperature.

FIG. 3 shows a third embodiment of the present invention.
In this example, pockets 4 each having a concave portion into which a ball 10 is fitted are provided at a plurality of circumferential positions on one side surface of the annular body 1, and the opening size B of the entrance of each pocket 4 is slightly smaller than the ball diameter. It is a dimension. The inner surface of the pocket 4 is spherical. The material of the cage is the same as in the example of FIG. In the illustrated example, the claws are eliminated to provide the minimum tightening margin, but the claws 3, 53 as in the example of FIG. 1 or 4 may be provided short. When the claw is provided, a slit may be provided in the claw as in the example of FIG. That is, in the example of FIG.
The nail 3 may be shortened. In the case of such a configuration, by reducing the range of holding the ball 10 by the retainer, the assembling force is reduced and the stress at the time of assembling is reduced. Also in the case of this configuration, a large stolen portion is provided between the pockets 4 on the back surface and the connecting piece 8 is provided as in the example of FIG.
May have a thickness that connects only the vicinity of the pitch circle. In that case, the slit 5 may be provided in the claw 3 as in the example of FIG. That is, the configurations of FIGS. 1, 2, and 3 may be combined arbitrarily.

[0012]

Since the resin cage according to claim 1 of the present invention has slits in each claw, even if a hard resin material is used, workability is not reduced and stress generated in the cage during assembly into a bearing is reduced. However, it is possible to prevent the bottom of the pocket from being whitened or cracked. In the resin retainer according to claim 2 of the present invention, since the connecting piece for connecting the pocket forming wall has a thickness for connecting only the vicinity of the pitch circle of the ball held in the pocket forming wall, a hard resin material can be used in this case as well. Without lowering workability, it is possible to reduce the stress generated in the cage during assembly into the bearing, and prevent the pocket bottom from being whitened or cracked. In the resin retainer according to claim 3 of the present invention, the opening size of the inlet portion of each pocket is set to be slightly smaller than the ball diameter. Therefore, in this case as well, workability is deteriorated even with a hard resin material. Without
In addition, it can be installed in the bearing without generating undue stress.

[Brief description of the drawings]

FIG. 1A is a sectional view of a first embodiment of the present invention,
(B) is the front view, (C) is the side view.

FIG. 2 is a partial side view of the second embodiment of the present invention.

FIG. 3A is a side view of a third embodiment of the present invention,
(B) is a partial enlarged side view of the ball holding state.

FIG. 4A is a rear view of the conventional example, FIG. 4B is a side view of the same,
(C) is the same front view, (D) is the same sectional view.

[Explanation of symbols]

1 ... Annular body, 2 ... Recess, 3 ... Claw, 4 ... Pocket, 5 ... Slit, 7 ... Pocket forming wall, 8 ... Connecting piece, 10 ... Ball

Claims (3)

[Claims] 1. At a plurality of circumferential positions on one side of the annular body,
A ball bearing resin retainer having a pocket for holding a ball, which comprises a recess into which a part of the ball fits and a pair of pawls protruding on both sides of the recess, wherein each of the pawls is provided with a slit along the axial direction. Resin cage for ball bearings characterized by 2. A ring-shaped resin retainer for ball bearings, wherein pocket forming walls for holding balls and connecting pieces are alternately formed, wherein each pocket forming wall is formed in a C shape having an opening on one width surface. A resin retainer for a ball bearing having a thickness in which the connecting piece is connected only in the vicinity of a pitch circle of a ball held by the pocket forming wall. 3. At a plurality of circumferential positions on one side surface of the annular body,
A resin retainer for ball bearings, in which pockets each having a recess into which a ball is fitted are provided, and the opening size of the entrance of each pocket is slightly smaller than the ball diameter.