JP2008240982A - Retainer for rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a retainer for a rolling bearing reducing rotation torque by reducing a contact area of a rolling element and the retainer. <P>SOLUTION: In the annular retainer 1, a pocket 3 for holding the rolling element 2 of the rolling bearing so as to be freely rolled is arranged on plural portions in the peripheral direction. A recessed and protruded surface 4 reducing the contact area with the rolling element 2 is provided on a portion on an inner peripheral surface 3a of the pocket 3 abutted on the rolling element 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cage for a rolling bearing.

  2. Description of the Related Art Conventionally, in a rolling bearing, a cage is used to hold a plurality of rolling elements at a constant interval and prevent friction between adjacent rolling elements in contact with each other. For example, a crown-shaped cage 101 made of a synthetic resin used for a ball bearing has a ball housing having a pocket inner peripheral surface 103a having a concave spherical shape similar to a ball at a plurality of circumferential positions of an annular body as shown in FIG. Pocket 103 for use (see, for example, Patent Document 1).

JP 7-279970 A

When a rolling bearing using such a crown-shaped cage 101 is rotated, the ball and the pocket inner peripheral surface 103a of the cage 101 are axially inner portions of the pocket 103 (indicated by P in FIG. 4) and Surface contact is made in the vicinity of the opening (indicated by Q in FIG. 4), but since the contact area is large, high torque of the ball bearing has been a problem.
This invention is made | formed in view of such a situation, and it aims at providing the rolling bearing retainer which can make rotational torque low by reducing the contact area of a rolling element and a retainer. Yes.

  A rolling bearing retainer according to the present invention is an annular retainer in which pockets for rolling the rolling elements of a rolling bearing are arranged at a plurality of locations in a circumferential direction, and the inner circumferential surface of the pocket An uneven surface that reduces a contact area with the rolling element is provided at a portion that contacts the rolling element.

  According to this rolling bearing retainer, since the rolling element comes into contact with the convex portion of the concave and convex surface by providing the concave and convex surface on the part of the inner peripheral surface of the pocket that contacts the rolling element, the inner periphery of the pocket The contact area between the surface and the rolling element can be reduced. Thereby, since the torque generated when the inner peripheral surface of the pocket comes into contact with the rolling elements is reduced, the rotational torque can be lowered.

In the rolling bearing retainer, when the retainer is a crown-shaped retainer for ball bearings, the uneven surface is provided in the inner part in the axial direction of the pocket, and the area of the uneven surface is the pocket. May occupy one half of the total area of the inner peripheral surface.
In this case, a concave and convex surface is provided in the axially inner back of the pocket where the balls are likely to come into contact so as to occupy one half of the total area of the inner peripheral surface of the pocket. The contact area with the moving body can be effectively reduced.

  According to the rolling bearing cage of the present invention, the rotational torque can be lowered by reducing the contact area between the rolling elements and the cage.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a perspective explanatory view showing a rolling bearing retainer according to one embodiment of the present invention. This rolling bearing retainer (hereinafter also referred to simply as a retainer) 1 is a ball bearing retainer that is assembled between an inner ring and an outer ring of a ball bearing, and is formed on an outer peripheral surface of the inner ring. This is for holding the balls 2 as a plurality of rolling elements, which are arranged so as to be able to roll between a raceway surface and an outer ring raceway surface formed on the inner peripheral surface of the outer ring, at regular intervals. The cage 1 is made of a synthetic resin and is configured as a so-called crown shape.

FIG. 2 is an enlarged perspective view of the cage 1 shown in FIG. 1, and FIG. 3 is a side view of FIG.
The cage 1 is an annular body formed by arranging pockets 3 for holding balls 2 as rolling elements at a plurality of locations in the circumferential direction. The pocket 3 has a concave spherical pocket inner peripheral surface 3 a having a shape similar to that of the ball 2 and having a radius of curvature slightly larger than the radius of curvature of the ball 2. When the ball bearing rotates, the ball 2 comes into contact with the pocket inner peripheral surface 3a while rolling.

  The pocket inner peripheral surface 3 a is provided with a concavo-convex surface 4 at the inner part in the axial direction of the pocket 3. The uneven surface 4 reduces the contact area between the ball 2 and the pocket inner peripheral surface 3a, and the uneven surface 4 is formed by providing a plurality of protrusions 4a that are convex portions. When the total area of the pocket inner peripheral surface 3a is 1, the area of the concavo-convex surface 4 (shown by hatching in FIG. 2) is 1/2 (0.5). That is, the area of the portion surrounded by the arc connecting A and B, the arc connecting straight lines BC, C and D and the straight line DA in FIG. 2 is half the total area of the pocket inner peripheral surface 3a (0 .5). In the present embodiment, the protrusion 4a is formed in a semispherical cross section as shown in FIG. 3, and the unevenness difference (height of the protrusion 4a) on the uneven surface 4 is set to about 20 μm.

  In the cage 1 configured as described above, the ball 2 is a convex portion of the concave / convex surface 4 by providing the concave / convex surface 4 at a portion of the inner peripheral surface 3a of the pocket 3 that contacts the rolling element (ball) 2. (Protrusions) Since they come into contact with 4a, the contact area between the inner peripheral surface 3a of the pocket 3 and the ball 2 can be reduced. Thereby, since the torque generated when the pocket inner peripheral surface 3a and the ball 2 come into contact with each other is reduced, the rotational torque can be lowered. In the present embodiment, the concave / convex surface 4 is provided so as to occupy an area of a half of the total area of the pocket inner peripheral surface 3a in the axially inner back portion of the pocket 3 where the ball 2 is easy to contact. The contact area between the pocket inner peripheral surface 3a and the ball 2 is effectively reduced.

  The present invention is not limited to the above embodiment and can be modified as appropriate. In the said embodiment, although it is set as the crown-shaped cage, it is good also as a cage of other shapes, such as a waveform. In addition, although the case where a ball bearing is used as the rolling bearing has been described, the cage of the present invention can be applied to other types of rolling bearings such as a tapered roller bearing and a needle roller bearing. It is possible to apply.

  In the above-described embodiment, the shape of the protrusion 4a that is the convex portion of the concavo-convex surface 4 is described as a semispherical cross section. In consideration of workability and the like, it can be formed into an arbitrary shape. Moreover, in the said embodiment, although the uneven surface 4 is formed by providing the protrusion 4a which is a convex part, since it is sufficient to reduce a contact area with a rolling element, by forming a recessed part, for example, a recessed groove, It is also possible to form the uneven surface 4. Furthermore, in the said embodiment, although the uneven surface 4 was provided in the axial inner back part of the pocket 3, and the area accounted for 1/2 of the total area of the pocket internal peripheral surface 3a, the uneven part 4 It suffices if it is formed in a portion of the pocket inner peripheral surface 3a that is in contact with the rolling element 2, and can be provided in a portion other than the inner back portion in the axial direction, and its area is also half of the total area. It is not limited to 1.

It is a perspective explanatory view showing a rolling bearing retainer according to one embodiment of the present invention. It is an expansion perspective explanatory drawing of the cage for rolling bearings shown by FIG. It is side surface explanatory drawing of FIG. It is an expansion perspective explanatory view of the conventional cage.

Explanation of symbols

1 Cage 2 Ball (rolling element)
3 Pocket 3a Pocket inner peripheral surface 4 Uneven surface 4a Protrusion (convex)

Claims (2)

  An annular retainer in which pockets for freely rolling rolling elements of a rolling bearing are arranged at a plurality of locations in the circumferential direction, and a portion of the inner circumferential surface of the pocket that is in contact with the rolling elements. A cage for a rolling bearing, wherein an uneven surface for reducing a contact area with a moving body is provided.   The cage is a crown-shaped cage for ball bearings, and the uneven surface is provided in the axially inner part of the inner peripheral surface of the pocket, and the area of the uneven surface is the inner periphery of the pocket The rolling bearing retainer according to claim 1, which occupies a half of a total area of the surface.

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