JP2009299820A - Retainer for rolling bearing and rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a retainer for a rolling bearing which reduces restoring force applied on a connection portion of a retainer segment in a split retainer and can prevents the connection portion from disconnecting by the restoring force. <P>SOLUTION: The circular retainer for the rolling bearing includes a plurality of retainer segments 1 comprising a strap-like segment body 2 formed with a pocket 7 for retaining rolling elements, a protruding hook portion 3 formed on one end in the longitudinal direction of the segment body 2 and a recessed hook portion 4 formed on other end in longitudinal direction of the segment body 2 and annularly formed by connecting the protruding hook portion 3 and the recessed hook portion 4 with each other by engagement of protrusions and recesses. On one surface of the outside face and inside face of the radial direction of the retainer segments 1, a recessed portion 9 recessed toward the other face is formed. In addition, the region on the inside or outside face in the radial direction of the retainer segments 1 overlapping the recessed portion 9 among the faces radially opposed to the face formed with the recessed portion 9 in the radial direction can be differentiated in the circumferential direction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rolling bearing cage and a rolling bearing. More specifically, the present invention relates to a rolling bearing cage composed of a plurality of segments that can be divided in the circumferential direction, and a rolling bearing including the cage.

Since the CT scanner rotating drum support bearing and the like are large, a cage in which a plurality of arc-shaped segments (divided pieces) are connected in an annular shape is usually used as a cage for holding a rolling element (for example, Patent References 1-2).
Such segmented cage segments are generally made of a synthetic resin such as polyamide. However, in order to have compatibility with bearings of different sizes, the elasticity of the synthetic resin can be used to make the arc from the arc during manufacture. Are often used in a large or small state.

Japanese Patent Laid-Open No. 2003-120680 JP 2004-19921 A

Since the cage segment is made of synthetic resin and has a predetermined elasticity, it is relatively easy to increase or decrease the arc diameter, but it can be restored by deforming it. A force (force to return to the original shape) is generated, and this restoring force acts on the connecting portion connecting the segments.
Thus, when it is used for a long time in a state where the restoring force is applied, there is a possibility that the connecting part is detached or the connecting part is damaged in some cases.

  The present invention has been made in view of such circumstances, and includes a rolling bearing retainer and a rolling bearing that can reduce a restoring force acting on a connection portion between retainer segments in a split retainer. It is intended to provide.

The rolling bearing retainer of the present invention (hereinafter also simply referred to as “retainer”) is formed at a strip-shaped segment body in which pockets for retaining rolling elements are formed, and at one end in the longitudinal direction of the segment body. A plurality of cage segments each having a convex locking portion and a concave locking portion formed at the other longitudinal end of the segment body;
An annular rolling bearing retainer formed by connecting the convex locking portion and the concave locking portion by concave and convex fitting,
A concave portion that is recessed toward the other surface is formed on one surface of the outer side and the inner side in the radial direction of the cage segment,
The outer or inner surface in the radial direction of the cage segment, the range overlapping the concave portion in the radial direction among the surfaces opposite to the surface in which the concave portion is formed can be differentiated in the circumferential direction. It is characterized by being made into a smooth surface.

In the cage of the present invention, a concave portion is formed on one surface of the outer side and the inner side of the radial direction of the cage segment, and the portion where the concave portion is formed is thinner than the other portion. Therefore, when assembling the retainer by connecting the retainer segments, the retainer segment can be easily bent, and the restoring force after assembly can be reduced. Since the restoring force can be reduced, the connecting portion will not come off or be damaged even if it is used for a long time.
Furthermore, since the range overlapping in the radial direction with the concave portion in the surface opposite to the surface in which the concave portion is formed is a surface that can be differentiated in the circumferential direction, when the cage segment is bent, the concave portion Stress is not concentrated on the opposite side. Therefore, generation of cracks due to stress concentration can be prevented.

The cage segment is made of synthetic resin,
The radial outer surface of each cage segment before being incorporated in the rolling bearing is a flat surface or a curved surface having a larger radius of curvature than the radially outer curved surface of the cage segment in a state of being incorporated in the rolling bearing. It can be. In this case, the cage segment is incorporated into the rolling bearing while being bent radially inward. However, the cage segment can be easily bent by forming the recess, and the restoring force after assembly Can be reduced.

  It is preferable that the concave portion is formed in a column portion between pockets formed in the segment body. According to this configuration, since the concave portion is formed in the column portion having relatively high strength in the segment main body, the segment main body can be easily bent while leaving the strength of the segment main body.

The rolling bearing of the present invention includes an inner ring having an inner ring raceway surface,
An outer ring disposed on the outer side of the inner ring and coaxially with the inner ring, and having an outer ring raceway surface facing the inner ring raceway surface;
A plurality of rolling elements disposed between the inner ring raceway surface and the outer ring raceway surface;
The cage is provided with the plurality of rolling elements held in the circumferential direction at predetermined intervals.

In the rolling bearing of the present invention, since the cage described above is used, when the cage is assembled by connecting the cage segments constituting the cage, the cage segment can be easily bent. The restoring force after assembly can be reduced. Since the restoring force can be reduced, the connecting portion will not come off or be damaged even if it is used for a long time.
Furthermore, since the range overlapping in the radial direction with the concave portion in the surface opposite to the surface in which the concave portion is formed is a surface that can be differentiated in the circumferential direction, when the cage segment is bent, the concave portion Stress is not concentrated on the opposite side. Therefore, generation of cracks due to stress concentration can be prevented.

  According to the cage and the rolling bearing of the present invention, it is possible to reduce the restoring force acting on the connecting portion between the cage segments in the split cage, and to prevent the connecting portion from being detached due to the restoring force.

Hereinafter, embodiments of a cage and a rolling bearing according to the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is an explanatory plan view of an example of a cage segment in the present invention. This cage segment 1 is a piece obtained by dividing an annular cage into an appropriate number (for example, 12). The cage segment 1 is entirely made of a synthetic resin such as polyamide, PEEK, or PPS in order to give a predetermined elasticity. The cage segment 1 includes a strip-shaped segment main body 2, a convex locking portion 3 formed at one end of the segment main body 2 in the longitudinal direction, and a concave engagement formed at the other longitudinal end of the segment main body 2. The stop part 4 is provided.

  As shown in FIG. 2, the cage segment 1 in the present embodiment does not have an arc shape like a conventional cage segment, and is linear. At the time of assembly, the lower surface of FIG. 2 is bent so as to be concave, and a plurality of them are connected to form an annular retainer. In the present specification, “radial direction” indicates a direction in a state of being assembled in an annular shape, and in the cage segment shown in FIG. 2, the lower surface is a radially inward surface, The upper surface is the radially outward surface.

  FIG. 5 shows a state in which the cage segments are assembled. FIG. 5A shows an annular cage that is completely closed by 12 cage segments 1, and FIG. ) Shows an annular retainer that is partially opened to form a gap G. In this specification, “annular” means not only a completely closed form as described above but also a partially opened form.

  The convex locking portion 3 in the present embodiment includes a base end portion 5 that protrudes outward from one end 2 a in the longitudinal direction of the segment body 2, and a retaining portion that is formed on the front end side of the base end portion 5. 6 is provided. The retaining portion 6 is wider than the base end portion 5 and has a substantially arrowhead shape as a whole. In addition, the concave locking portion 4 in the present embodiment is formed as a concave portion having a shape corresponding to the shape of the convex locking portion 3 so that the convex locking portion 3 can be fitted. Since the concave engaging portion 4 is formed at the other longitudinal end 2b of the main body 2, the longitudinal other end 2b of the segment main body 2 is bifurcated. An annular cage can be obtained by connecting the convex locking part 3 and the concave locking part 4 by concave-convex fitting. FIG. 3 is an explanatory plan view of the convex locking portion 3, the concave locking portion 4 and the connecting portion.

  The segment body 2 includes a plurality of pockets 7 at predetermined intervals in the longitudinal direction. The pocket 7 is formed as a hole penetrating in the thickness direction of the segment body 2 in order to hold rolling elements such as balls and rollers. 1 to 3, reference numeral 8 denotes a guide rib that is provided along one side edge in the width direction of the segment body 2 and that is formed so as to be able to contact the raceway during rotation.

  On the radially inner surface of the segment body 2, a recess 9 that is recessed toward the radially outer surface of the segment body 2 is formed. The recess 9 is formed over the entire width direction of the segment body 2 and has a substantially arcuate cross section as shown in FIG. Since the portion where the recess 9 is formed is thinner than the other portions, the cage segment 1 can be easily bent when the cage segment 1 is assembled by assembling the cage. Further, the restoring force after assembly can be reduced. As a result, even if it is used for a long time, the connecting portion between the cage segments 1 is not detached or damaged.

  Further, at least a range overlapping with the concave portion 9 formed in the radially inner surface of the segment body 2 in the radial direction is a differentiable surface. For this reason, when the cage segment 1 is bent during assembly, stress does not concentrate on the radially outward surface, which is the surface opposite to the recess 9. Therefore, generation of cracks due to stress concentration can be prevented. Here, the “differentiable” surface means a flat surface or a continuous curved surface. In other words, a convex portion or a projection that forms a corner (corner portion) where stress concentration is likely to occur is formed. It means not a side.

  The concave portion 9 is formed in a column portion 10 between adjacent pockets 7. If the concave portion 9 is formed in the pocket 7 portion, the strength of the pocket 7 portion is relatively small, so that the cage may be damaged during assembly or use, but the column portion 10 is relatively strong. Therefore, by forming the recess 9 in the column portion 10, the segment body 2 can be easily bent while leaving the strength of the segment body 2, that is, the cage segment 1.

As shown in FIG. 2, the recess 9 is preferably formed entirely in the pillar portion 10, but as long as the required bending strength is ensured, a part of the recess 9 is pocketed as shown in FIG. 7 can also be formed on the member 7a constituting the member 7.
Moreover, the shape of the recessed part 9 is not specifically limited in this invention, For example, in addition to the circular arc shape shown in FIG. 2, it can be set as a triangle shape or a rectangle as shown in FIG. However, from the viewpoint that stress concentration due to bending is small, a curved shape such as an arc shape is preferable.

  The recesses 9 may be formed between the pockets, or may be formed, for example, every other pocket. Furthermore, it may be formed only in the vicinity of both ends in the longitudinal direction of the cage segment 1, and in the present invention, the location where the recess 9 is formed is not particularly limited.

  The cage segment 1 in the present embodiment is linear as shown in FIG. 2, but may be arcuate as shown in FIG. The radially outer surface 11a of the cage segment 11 shown in FIG. 4A is radially outward of the cage segment 11 (see FIG. 4B) when incorporated in a rolling bearing. The curved surface has a larger radius of curvature than the curved surface. The cage segment 11 is incorporated into the rolling bearing while being bent radially inward. However, the cage segment 11 can be easily bent by forming the concave portion as described above, and after assembly. The restoring force can be reduced.

  In the embodiment described above, the concave portion is formed on the radially inner surface of the cage segment, but the concave portion that is recessed radially inward is formed on the radially outer surface. You can also. When assembling the cage by deforming the cage segment so that the arc diameter of the arc-shaped cage segment is increased, the cage segment is formed by forming a recess on the radially outer surface. It can be easily bent. In this case, at least a range overlapping in the radial direction with the concave portion formed on the radially outer surface of the segment main body is made a differentiable surface.

  Although not shown, the cage according to the embodiment described above has an inner ring having an inner ring raceway surface, and an outer ring raceway surface disposed coaxially with the inner ring on the outer side of the inner ring and facing the inner ring raceway surface. It can be suitably used as a cage in a large-sized rolling bearing provided with an outer ring and a plurality of rolling elements disposed between the inner ring raceway surface and the outer ring raceway surface.

It is a plane explanatory view of an example of a cage segment in the present invention. It is side surface explanatory drawing of the holder | retainer segment shown by FIG. It is a plane explanatory view of the joined portion of the cage segment shown in FIG. It is side surface explanatory drawing of the other example of the holder | retainer segment in this invention. It is side explanatory drawing of the cage | basket of the assembled state. It is side surface explanatory drawing of the other example of the recessed part formed in a holder | retainer segment. It is side surface explanatory drawing of the further another example of the recessed part formed in a holder | retainer segment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cage segment 2 Segment main body 3 Convex-shaped latching part 4 Concave-shaped latching part 7 Pocket 9 Recessed part 10 Pillar part 11 Cage segment

Claims (4)

A strip-shaped segment main body in which pockets for holding rolling elements are formed, a convex locking portion formed at one end of the segment main body in the longitudinal direction, and a concave engagement formed at the other longitudinal end of the segment main body And a plurality of retainer segments with stops,
An annular rolling bearing retainer formed by connecting the convex locking portion and the concave locking portion by concave and convex fitting,
A concave portion that is recessed toward the other surface is formed on one surface of the outer side and the inner side in the radial direction of the cage segment,
The outer or inner surface in the radial direction of the cage segment, the range overlapping the concave portion in the radial direction among the surfaces opposite to the surface in which the concave portion is formed can be differentiated in the circumferential direction. A rolling bearing retainer characterized in that it is formed into a smooth surface. The cage segment is made of synthetic resin;
The radially outer surface of each cage segment before being incorporated into the rolling bearing is a flat surface, or the radius of curvature is larger than the radially outward curved surface of the cage segment in the state of being incorporated into the rolling bearing. The cage for a rolling bearing according to claim 1, which has a large curved surface.   The rolling bearing retainer according to claim 1, wherein the recess is formed in a column portion between pockets formed in the segment body. An inner ring having an inner ring raceway surface;
An outer ring disposed on the outer side of the inner ring and coaxially with the inner ring, and having an outer ring raceway surface facing the inner ring raceway surface;
A plurality of rolling elements disposed between the inner ring raceway surface and the outer ring raceway surface;
A rolling bearing comprising: the cage according to any one of claims 1 to 3, which holds the plurality of rolling elements at a predetermined interval in a circumferential direction.

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