JP2008190663A - Ball bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ball bearing whose retainer can be prevented from being deformed in a twisted manner at the time of its high-speed rotation. <P>SOLUTION: The ball bearing 10 is equipped with an outer ring 11 with an outer-ring raceway surface 11a in its inner circumferential surface, an inner ring 12 with an inner-ring raceway surface 12a in its outer circumferential surface, a plurality of rolling bodies 13 arranged in a freely rollable manner between the outer-ring raceway surface 11a and the inner-ring raceway surface 12a, and a retainer 14 which holds circumferentially the rolling bodies 13 at regular intervals. The retainer 14 holds rollably the rolling bodies 13 and has pockets 15 mutually adjacent circumferentially, while the pocket 15 is cylindrically formed radially and is provided with a protrusion 18 along a radial edge of the inner circumferential surface of the pocket 15. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a ball bearing, and more particularly to a ball bearing for high-speed rotation.

  As a conventional ball bearing, a ball bearing 50 as shown in FIG. 6 is known. In this ball bearing 50, a plurality of balls 53 that are rolling elements are disposed between an outer ring 51 and an inner ring 52. This is a deep groove ball bearing, and the plurality of balls 53 are held so as to be able to roll at substantially equal intervals in the circumferential direction via an annular crown-shaped cage 54 as shown in FIG. 1).

  The crown-shaped cage 54 is formed by injection molding of synthetic resin or the like, and the crown-shaped cage 54 has a pocket portion 55 that holds a plurality of balls 53 so as to roll in a circumferential direction at substantially equal intervals. A pair of claw portions 56 protruding in the axial direction are provided at both ends in the circumferential direction of the inner peripheral surface of the pocket portion 55. An opening 57 is formed between the pair of claws 56, 56, and the ball 53 is pushed from the opening 57 into the pocket 55 while spreading the pair of claws 56. The ball 53 is held in a rollable manner through a minute gap.

Japanese Unexamined Patent Publication No. 2003-35317 (2nd page, FIG. 8)

  However, the crown type cage 54 incorporated in the conventional ball bearing 50 is a rolling element guide type cage, and the opening 57 side and the cage rim side have an asymmetric cross-sectional shape in the axial direction. In response to the recent high speed rotation, as shown in FIG. 8, the centrifugal force due to the cage rotation (rolling element revolution) acts on the axial end on the opening 57 side, and the axial end on the cage rim side There is a possibility that torsional deformation occurs due to elastic or plastic deformation with the portion as a torsion axis.

  The present invention has been made to eliminate such inconveniences, and an object of the present invention is to provide a ball bearing capable of preventing torsional deformation of the cage during high-speed rotation.

The above object of the present invention can be achieved by the following constitution.
(1) An outer ring having an outer ring raceway surface on an inner peripheral surface, an inner ring having an inner ring raceway surface on an outer peripheral surface, and a plurality of rolling elements disposed so as to be rollable between the outer ring raceway surface and the inner ring raceway surface; And a cage that holds the rolling elements at equal intervals in the circumferential direction, the cage holding the rolling elements in a rollable manner and having pocket portions adjacent to each other in the circumferential direction. The pocket portion is formed in a cylindrical shape in the radial direction, and a projection is provided along the radial edge of the inner peripheral surface of the pocket portion.
(2) The ball bearing according to (1), wherein the protrusions are provided on both sides in the circumferential direction of the radial end edge of the inner peripheral surface of the pocket portion.
(3) The ball bearing according to (1), wherein the protrusion is provided over the entire circumference of the radial end edge of the inner peripheral surface of the pocket portion.
(4) The ball bearing according to any one of (1) to (3), wherein the protrusion is provided on an inner edge in the radial direction of the inner peripheral surface of the pocket portion.

  According to the ball bearing of the present invention, the cage holds the rolling element in a rollable manner and has pocket portions adjacent to each other in the circumferential direction, and the pocket portion is formed in a cylindrical shape in the radial direction, Torsional deformation of the cage by elastic or plastic deformation with the axial end on the cage rim side generated on the opening side of the cage as the torsion axis, in order to provide projections along the radial edge of the inner peripheral surface of the cage Can be suppressed.

Hereinafter, one embodiment of a ball bearing concerning the present invention is described in detail with reference to drawings.
1 is a partially cutaway perspective view for explaining an embodiment of a ball bearing according to the present invention, FIG. 2 is a perspective view for explaining a cage shown in FIG. 1, and FIG. 3 is a cage shown in FIG. FIG. 4 is a perspective view for explaining a first modified example of the cage, and FIG. 5 is a perspective view for explaining a second modified example of the cage.

  As shown in FIG. 1, the ball bearing 10 of the present embodiment includes an outer ring 11 having an outer ring raceway surface 11a on an inner peripheral surface, an inner ring 12 having an inner ring raceway surface 12a on an outer peripheral surface, an outer ring raceway surface 11a and an inner ring raceway. A plurality of balls (rolling elements) 13 disposed so as to be freely rollable between the surface 12a and a crown-shaped cage (cage) 14 that holds the balls 13 at equal intervals in the circumferential direction.

  The crown type retainer 14 is integrally formed by injection molding of synthetic resin or the like, and has an outer ring guide type (tracked ring guide type) guided by the inner peripheral surface of the groove shoulder 11b of the outer ring 11. As shown in FIG. 2, the crown-shaped cage 14 is formed with pockets 15 that hold a plurality of balls 13 so as to roll in the circumferential direction at substantially equal intervals, and are adjacent to each other in the circumferential direction. A pair of claw portions 16 projecting in the axial direction are provided at both circumferential ends of the inner peripheral surface of the pocket portion 15. In addition, an opening 17 is formed between the tips of the pair of claws 16, and the ball 13 is pushed from the opening 17 into the pocket 15 while spreading the pair of claws 16. The ball 13 is held in a rollable manner through a minute gap.

  The resin material of the crown-shaped cage 14 is polyamide resin such as 46 nylon or 66 nylon, polybutylene terephthalate, polyferene sulfide (PPS), polyamideimide (PAI), thermoplastic polyimide, polyether ether ketone (PEEK). And polyether nitrile (PEN). Further, the rigidity and dimensional accuracy of the cage can be improved by appropriately adding 10 to 50% by weight of a fibrous filler (for example, glass fiber or carbon fiber) to these resins.

  In the present embodiment, as shown in FIGS. 2 and 3, the pocket portion 15 is formed in a cylindrical shape in the radial direction, and the protrusion 18 extends along the radial edge of the inner peripheral surface of the pocket portion 15. Provided. The protrusions 18 are respectively provided on both sides in the circumferential direction of the radially inner end edge of the inner peripheral surface of the pocket portion 15.

  As described above, according to the ball bearing 10 of the present embodiment, the pocket portion 15 is formed in a cylindrical shape in the radial direction, and both sides in the circumferential direction of the radially inner edge of the inner peripheral surface of the pocket portion 15. Since the protrusions 18 are respectively provided on the caps 14, even if the crown-shaped cage 14 is twisted and deformed, the clearance between the balls 14 and the inner peripheral surface of the pocket portion 15 can be maintained within an appropriate range. The action of pushing the pair of claw portions 16 of the 14 to be spread can be suppressed, and the opening of the cage 14 can be reduced by the protrusion 18 coming into contact with the ball 13. Accordingly, the torsional deformation of the cage 14 due to the elastic or plastic deformation with the axial end on the cage rim side generated on the opening 17 side of the cage 14 as a torsion axis can be suppressed.

  Moreover, according to the ball bearing 10 of this embodiment, since the crown type cage 14 is an outer ring guide type (tracked ring guide type), the stability of the cage 14 during high-speed rotation can be improved.

  As a first modification of the present embodiment, as shown in FIG. 4, the protrusion 18 of the crown-shaped cage 14 is provided over the entire circumference of the radially inner edge of the inner peripheral surface of the pocket portion 15. It may be done. In this case, since the contact area between the balls 13 and the cage 14 is increased, the stress applied to the protrusions 18 can be relaxed.

  As a second modification of the present embodiment, in the crown-type cage 14 shown in FIG. 2, a step is provided between the outer circumferential surface of the cage rim side guide surface and the opening 17 side non-guide surface. However, as shown in FIG. 5, the guide surface on the cage rim side and the non-guide surface on the opening 17 side of the outer peripheral surface of the crown type cage 14 may be flush with each other.

1 is a partially cutaway perspective view for explaining an embodiment of a ball bearing according to the present invention. It is a perspective view for demonstrating the holder | retainer shown in FIG. It is a principal part expansion perspective view of the holder | retainer shown in FIG. It is a perspective view for demonstrating the 1st modification of a holder | retainer. It is a perspective view for demonstrating the 2nd modification of a holder | retainer. It is principal part sectional drawing for demonstrating the conventional ball bearing. It is a perspective view for demonstrating the conventional crown type holder | retainer integrated in the ball bearing shown in FIG. It is principal part sectional drawing for demonstrating the torsion deformation which arises in the conventional crown type holder | retainer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Ball bearing 11 Outer ring 11a Outer ring raceway surface 12 Inner ring 12a Inner ring raceway surface 13 Ball (rolling element)
14 Crowned cage (Retainer)
15 Pocket 16 Claw 17 Opening 18 Projection

Claims (4)

An outer ring having an outer ring raceway surface on an inner peripheral surface, an inner ring having an inner ring raceway surface on an outer peripheral surface, and a plurality of rolling elements disposed to be freely rollable between the outer ring raceway surface and the inner ring raceway surface; A retainer for holding the rolling elements at equal intervals in the circumferential direction,
The cage holds the rolling element so as to be able to roll, and has pocket portions adjacent to each other in the circumferential direction,
The pocket portion is formed in a cylindrical shape in the radial direction,
A ball bearing, wherein a protrusion is provided along a radial edge of the inner peripheral surface of the pocket portion.   2. The ball bearing according to claim 1, wherein the protrusions are provided on both circumferential sides of a radial edge of the inner peripheral surface of the pocket portion.   The ball bearing according to claim 1, wherein the protrusion is provided over the entire circumference of the radial end edge of the inner peripheral surface of the pocket portion.   The ball bearing according to claim 1, wherein the protrusion is provided on an inner edge in the radial direction of the inner peripheral surface of the pocket portion.

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