Roller bearing cage and tapered roller bearing

Abstract

A roller bearing cage is made of a resin and has a tapered tubular shape as a whole. In the roller bearing cage, tapered rollers are forcibly fitted to pockets while elastically deforming pillar portions at a small-diameter annular portion side. A stress alleviating portion is provided on at least an outer circumferential side of an end of the pillar portion at the small-diameter annular portion side so that a portion of the pillar portion from a crossing portion between the pillar portion and the small-diameter annular portion to a side of the large-diameter annular portion is linearly cut, thereby alleviating the stress occurring in the pillar portion when the tapered roller is forcibly fitted to the pocket.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view illustrating a main portion of a tapered roller bearing according to a first embodiment of the invention.

FIG. 2 is a lateral view illustrating a cage.

FIG. 3 is an enlarged perspective view illustrating a main portion of a cage.

FIG. 4 is a cross-sectional view taken along the line A-A of FIG. 3.

FIG. 5 is a cross-sectional view illustrating a rolling bearing device that is a tapered roller bearing according to a second embodiment of the invention.

FIGS. 6A and 6B are diagrams illustrating the related art, FIG. 6A is a diagram illustrating a state where a tapered roller is forcibly fitted to a pocket, and FIG. 6B is a cross-sectional view of a cage where cutout portions are provided in a crossing portion in order to release an edge of a tapered roller.

FIG. 7 is a schematic diagram illustrating an assembling state of a tapered roller bearing.

Claims

1. A roller bearing cage made of a resin and having a tapered tubular shape as a whole, the roller bearing cage comprising: a large-diameter annular portion and a small-diameter annular portion that are concentrically arranged in an axial direction;a plurality of pillar portions that extend between the large-diameter annular portion and the small-diameter annular portion at a plurality of positions in a circumferential direction;pockets that are defined between the pillar portions, tapered rollers being forcibly fitted to the pockets while elastically deforming the pillar portions at a side of the small-diameter annular portion; anda stress alleviating portion provided on at least an outer circumferential side of an end of the pillar portion at a side of the small-diameter annular portion for alleviating stress occurring in the pillar portion when the tapered roller is forcibly fitted to the pocket,wherein the stress alleviating portion is formed so that a portion of the pillar portion from a crossing portion between the pillar portion and the small-diameter annular portion to a side of the large-diameter annular portion is linearly cut.

2. The roller bearing cage according to claim 1, wherein the stress alleviating portion is formed in a shape tapered from the crossing portion to the side of the large-diameter annular portion.

3. The roller bearing cage according to claim 1, wherein a plurality of the stress alleviating portions are provided on opposite sides of all the pillar portions in a circumferential direction.

4. The roller bearing cage according to claim 3, wherein at least a portion of the pillar portions at the small-diameter annular portion side is formed to have a trapezoidal section in a circumferential direction, anda circumferential minimum width of the portion where the stress alleviating portions are provided is equal to or larger than a circumferential width of an inner circumferential surface of the pillar portion.

5. A tapered roller bearing comprising: an inner ring member;an outer ring member;a plurality of tapered rollers that are interposed between the inner ring member and the outer ring member; anda roller bearing cage made of a resin and having a tapered tubular shape as a whole that rotatably retains the plurality of tapered rollers,wherein the roller bearing cage comprises;a large-diameter annular portion and a small-diameter annular portion that are concentrically arranged in an axial direction;a plurality of pillar portions that extend between the large-diameter annular portion and the small-diameter annular portion at a plurality of positions in a circumferential direction;pockets that are defined between the pillar portions, the tapered rollers being forcibly fitted to the pockets while elastically deforming the pillar portions at a side of the small-diameter annular portion; anda stress alleviating portion provided on at least an outer circumferential side of an end of the pillar portion at a side of the small-diameter annular portion for alleviating stress occurring in the pillar portion when the tapered roller is forcibly fitted to the pocket,wherein the stress alleviating portion is formed so that a portion of the pillar portion from a crossing portion between the pillar portion and the small-diameter annular portion to a side of the large-diameter annular portion is linearly cut.

6. The tapered roller bearing according to claim 5, wherein the stress alleviating portion is formed in a shape tapered from the crossing portion to the side of the large-diameter annular portion.

7. The tapered roller bearing according to claim 5, wherein a plurality of the stress alleviating portions are provided on opposite sides of all the pillar portions in a circumferential direction.

8. The tapered roller bearing according to claim 7, wherein at least a portion of the pillar portions at the small-diameter annular portion side is formed to have a trapezoidal section in a circumferential direction, anda circumferential minimum width of the portion where the stress alleviating portions are provided is equal to or larger than a circumferential width of an inner circumferential surface of the pillar portion.