JPH08326744A - Shell-type needle roller bearing - Google Patents

Abstract

PURPOSE: To provide a shell-type needle roller bearing which can prevent the running of a roller onto a retainer and can withstand even quick acceleration or high-speed rocking revolution. CONSTITUTION: A shell-type needle roller bearing of inner-ringless type consisting of a needle roller 2, an outer ring 3, and a retainer 4 is provided with a projection 6 at the inner face of the pole 4a between each pocket 5 and the next 5 of the retainer 4. The retainer 4 is one molded by a press, and besides is roller guide type of one where each roller 2 is retained, in the condition of being prevented from slip off only to the inner face side, in each pocket 5 lined up in the circumferential direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shell type needle roller bearing which can be used in a clutch fork portion of a large vehicle, a power steering or the like where a sudden acceleration or a swing motion is performed.

[0002]

2. Description of the Related Art FIG. 3 shows a cross section of a shell needle roller bearing using a conventional U-shaped cage. This shell-type needle roller bearing is of a type without an inner ring, and is composed of a needle roller 2 to be brought into rolling contact with a shaft 1, an outer ring 3 of a deep-drawn molded product, and a press-molded cage 4. The U-shaped cage 4 is of a type guided by the rollers 2 and holds the rollers 2 in the pockets 5 (FIG. 4) arranged in the circumferential direction only on the inner diameter side in a falling prevention state.

[0003]

The roller guide type cage 4 has a structure in which the amount of downward movement (the amount of radial movement) of the cage 4 is restricted by the rollers 2, and the cage itself is lowered. It is not structured to regulate the amount. That is, the roller 2 is the opening edge 5a on the outer diameter side of the pocket 5 of the cage 4.
The retainer 4 is guided in contact with and the amount of downward movement is regulated. Therefore, when the amount of lowering is large due to wear of the retainer opening edge portion or elastic deformation of the ring portion, there is a high possibility that the inner diameter surface of the cage 4 and the outer diameter surface of the shaft 1 make line contact, and the oil film forming ability There is a concern that the life may be limited due to the decrease. Further, since the amount of downward movement is large, the roller 2 easily rides up on the pillar portion 4a between the pockets 5 and 5 of the cage 4 during sudden acceleration, forward and reverse swinging rotation, and the like, which hinders smooth rotation. Therefore, there is a limit to sudden acceleration and rocking speed. This riding phenomenon becomes more likely to occur as the cage outer diameter dimension d1 becomes smaller.

To solve this problem, if the cage outer diameter dimension d1 can be increased and the rollers 2 can be held by the pitch circle PCD, riding will not occur, but the cage 4 is thin and has a claw shape. If there is no roller stop portion such as a portion, the roller 2 will fall out toward the inner diameter side if designed in this way, and the roller cannot be guided. Therefore, it is necessary to have a structure that regulates the amount of lowering of the cage 4 without changing the outer diameter dimension d1.

It is an object of the present invention to provide a shell type needle roller bearing which can prevent a roller from riding on a cage and can withstand sudden acceleration and high-speed oscillating rotation.

[0006]

A bearing according to the present invention has needle rollers, an outer ring, and a cage, and the cage is a press-molded cage, and is provided in each pocket arranged in the circumferential direction. A shell type needle roller bearing that is a roller guide type retainer that holds each roller only in the inner diameter side in a falling prevention state, characterized in that a protrusion is provided on the inner diameter surface of the column portion between each pocket of the retainer. And It should be noted that this bearing may be of the type without inner ring or of the type with inner ring. The protrusion may be provided on the outer diameter surface of the cage column. In that case, the said protrusion shall have a surface which follows the opening edge of a pocket.

[0007]

Since the protrusion protrudes from the inner diameter surface of the retainer, the amount of downward movement of the retainer in the diametrical direction can be restricted by the retainer itself. Therefore, the riding of the roller is prevented. That is, the movement of the cage in the radial direction is restricted by the protrusions, and a substantial reduction in the outer diameter of the cage is prevented. Therefore, the riding of the roller is prevented. When the protrusion is provided on the outer diameter surface of the cage, even if the amount of lowering of the cage increases, the roller comes into contact with the protrusion on the outer diameter surface of the cage to prevent the roller from riding up.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIG. In the figure, the same reference numerals are given to the portions corresponding to the example of FIG. This shell-shaped needle roller bearing is of a type without an inner ring, which has a needle roller 2 rollingly contacting a shaft 1, an outer ring 3, and a cage 4. The outer ring 3 is formed by heat-treating a deep drawn product of a steel plate and has an inward groove-shaped cross section. The cage 4 is a U-shaped ring-shaped member having outwardly facing flange portions 4b on both side edges. For example, a metal plate such as a strip-shaped steel plate formed into a groove is rolled and welded at both ends. Then it is made into a ring shape. In addition to this, the thin steel plate may be formed by deep drawing or rolling to form the cage 4, and may be manufactured by a non-welding method. The cage 4 is of a roller guide type in which the rollers 2 are retained in the pockets 5 arranged in the circumferential direction only on the inner diameter side in a falling prevention state. That is, the outer diameter dimension d1 of the cage 4 is the pitch circle PCD of the roller 2.
It is assumed that the diameter of the cage 4 is slightly smaller than that of the cage 4, and the opening edge 5a of the pocket 5 on the outer diameter surface side of the cage is in contact with the roller 2 to guide the cage 4.

In this structure, the protrusion 6 is provided on the inner diameter surface of the column portion 4a between the pockets 5 and 5 of the cage 4. Protrusion 6
Is a countersink shape formed by press molding, and has a trapezoidal cross section parallel to the axial center.
Extends over the entire width of. The number of protrusions 6 on each pillar 4a is
The number may be one or plural, and in this embodiment, two are formed at positions near both ends in the width direction of the cage.

According to this construction, the protrusion 6 protruding from the inner diameter surface of the cage 4 limits the amount of downward movement of the cage 4 in the diametrical direction by the cage itself. Therefore, the riding of the roller 2 is prevented. That is, the radial movement of the cage 4 is restricted by the protrusions 6, and the cage outer diameter dimension d1.
The substantial dimension of is kept above a certain value. Therefore, it is possible to prevent the roller 2 from riding up, and to have a bearing specification that can withstand sudden acceleration and high-speed forward / reverse oscillating rotation.

FIG. 2 shows another embodiment of the present invention. In this example, instead of the protrusion 6 of the cage 4 in the embodiment of FIG. 1, a protrusion 7 protruding to the outer diameter surface is provided on each column portion 4a. The projection 7 is also of a counter sink shape formed by press molding, and has a trapezoidal cross section parallel to the axis and extends over the entire width of the column portion 4a. Therefore, the protrusion 7
The end portion of is a surface 7a along the opening edge of the pocket 5. The number of the protrusions 7 on each of the pillar portions 4a may be one or plural. In this embodiment, two protrusions 7 are formed at positions near both ends in the cage width direction. The height of the protrusions 7 is set so as to reach the pitch circle PCD of the rollers 2 or slightly to the pitch circle PCD. With this configuration,
Since the protrusion 7 is provided on the outer diameter surface of the cage 4, the lowering amount is not restricted by the retainer 4 itself. As a result, the roller 2 is prevented from riding on the pillar portion 4a.
Therefore, also in this case, it is possible to endure sudden acceleration and high-speed swing rotation.

[0012]

In the shell-shaped needle roller bearing according to the first aspect of the present invention, since the protrusion is provided on the inner diameter surface of the column portion between the pockets of the cage, the amount of downward movement of the cage is restricted by the cage itself. , It prevents the rollers from riding on the cage. Therefore, it can withstand sudden acceleration and high-speed rocking rotation. Claim 2
In the case of the invention, since the protrusion is provided on the outer diameter surface of the cage,
Even if the amount of lowering of the cage becomes large, the rollers come into contact with the protrusions on the outer diameter surface of the cage, thereby preventing the rollers from riding up. Therefore, also in this case, it is possible to endure sudden acceleration and high-speed swing rotation.

[Brief description of drawings]

FIG. 1A is a sectional view of an embodiment of the present invention, and FIG.
Is a partially developed view of the cage as viewed from the outer diameter side, and (C) is a partially enlarged sectional view of the cage.

FIG. 2A is a sectional view of another embodiment of the present invention,
(B) is a partial development view of the cage viewed from the outer diameter side,
(C) is a partial expanded sectional view of a cage.

FIG. 3 is a sectional view of a conventional example.

FIG. 4 is a partially enlarged sectional view of the cage.

[Explanation of symbols]

1 ... Shaft, 2 ... Roller, 3 ... Outer ring, 4 ... Retainer, 4a ... Pillar part, 5 ... Pocket, 6, 7 ... Projection, 7a ... Surface

Claims (2)

[Claims] 1. A needle roller, an outer ring, and a cage,
In the shell needle roller bearing, wherein the cage is a press-molded cage, and in each pocket arranged in the circumferential direction, a roller guide type cage that retains each roller only in the inner diameter side in a falling prevention state, A shell-shaped needle roller bearing, characterized in that a protrusion is provided on the inner diameter surface of the column portion between each pocket of the cage. 2. The shell-shaped needle roller bearing according to claim 1, wherein the protrusions protruding from the inner diameter surface of the cage are replaced by:
A shell needle roller bearing in which a protrusion is provided on the outer diameter surface, and the protrusion has a surface along the opening edge of the pocket.