JP2020045944A - Holder for rolling bearing and rolling bearing - Google Patents

Abstract

To provide a holder for a rolling bearing capable of abolishing a fitting structure between segments, preventing adjacent segments from contacting each other, and improving integration workability, and a rolling bearing using the holder.SOLUTION: A holder for a rolling bearing is formed in an annular shape with at least two arc-shaped segments. Each arc-shaped segment has pockets arranged at a predetermined pitch along a circumferential direction. Each of the opposite surfaces of the segments adjacent in the circumferential direction has a flat surface shape. The holder is formed in the annular shape with a gap formed between the opposite surfaces of the facing segments.SELECTED DRAWING: Figure 1

Description

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

  FIG. 9 shows a general rolling bearing. The rolling bearing in this case is a ball bearing. The ball bearing includes an inner ring 1 having an inner rolling surface 1a formed on an outer diameter surface, an outer ring 2 having an outer rolling surface 2a formed on an inner diameter surface, and an inner ring. A plurality of balls (balls) 3 are disposed between the inner race 1 and the outer race 2 as rolling elements rotatably interposed between the inner race 1 and the outer race 2a. The main part is constituted by a crown-shaped retainer 4 made of resin which holds the balls 3 at equal intervals in the circumferential direction.

  As shown in FIG. 10, a crown-shaped retainer 4 disposed between the inner ring 1 and the outer ring 2 has an annular main portion 5a and an axially one surface of the main portion 5a spaced apart from each other. It is composed of a pair of elastic pieces 5b and 5b integrally projecting in the circumferential direction and is provided between the pair of elastic pieces 5b and 5b so as to be recessed between the outer diameter side and the inner diameter side. An open pocket 5c is provided, and the ball 3 is rollably held by the pocket 5c.

  By the way, a CT scanner device has a rotating body (rotary gantry) equipped with an X-ray tube device for irradiating X-rays and a detector for receiving the radiated X-rays, which is rotatable with respect to a fixed body (fixed gantry). A rolling bearing is incorporated for supporting the bearing, and as the incorporated rolling bearing, a bearing whose wall thickness is extremely small with respect to the diameter, that is, an ultra-thin rolling bearing is usually selected. In this type of CT scanner device, it is necessary to minimize the occurrence of vibrations and abnormal sounds during driving in order to prevent a subject entering the inner periphery of the fixed gantry during image formation from feeling uneasy. Therefore, the rolling bearing incorporated in this type of CT scanner device is required to minimize the occurrence of vibration and abnormal noise during operation.

As a cage for such an ultra-thin type rolling bearing, for reasons of production and assembly,
As described in Patent Literatures 1 to 3, a retainer in which a plurality of segments are combined is often used.

  As shown in FIG. 11, the segment 7 having a plurality of pockets includes an arc-shaped main body 9 in which concave portions 8 are formed at a predetermined pitch, and a pair of projecting protrusions from the opening ends of the concave portions 8 of the main body portion 9. A pocket 11 is formed by a pair of claw portions 10, 10 having claw portions 10 and facing the recess 8.

  Further, a fitting projection 12 is provided at one end of the segment 7 and a fitting recess 13 is provided at the other end. In this case, for example, the fitting projection 12 includes a neck 12a and a circular head 12b continuously provided from the neck 12a, and the fitting recess 13 also corresponds to the fitting projection 12, It comprises a neck 13a and a circular head 13b connected to the neck 13a.

  For this reason, as shown in FIG. 12, by fitting the fitting projection 12 of one segment 7 into the fitting recess 13 of the other segment 7, the segments adjacent in the circumferential direction are connected (coupled). You. In this case, the fitting projection 12 and the fitting recess 13 are pushed in from the radial direction.

JP 2010-71386 A JP 2007-64406 A JP 2004-218745 A

  In the case where the fitting projection 12 is fitted into the fitting recess 13, an appropriate interference is given to the fitting portion 15 (see FIG. 12), whereby the circumferentially adjacent segments 7, 7 are joined. By doing so, an annular retainer 4 is formed.

  By the way, the segments 7, 7 forming such a retainer 4 are generally injection-molded products made of resin. For this reason, the interference of the fitting portion 15 may increase due to a molding error or the like, or the interference may decrease and rattling may occur in the fitting portion 15.

  When the interference of the fitting portion 15 of the segments 7 and 7 increases, when the fitting protrusion 12 is pushed into the fitting recess 13 on the other side from the radial direction, it easily interferes with both, so that the fitting can be smoothly fitted. Difficult, greatly reducing workability. Conversely, when the interference of the fitting portions 15 of the segments 7, 7 is reduced and rattling occurs (see FIG. 13), a shift in the inner diameter direction or the outer diameter direction occurs between the adjacent segments 7, 7. . For this reason, the displaced segments 7, 7 come into contact with the inner raceway surface 1a or the outer raceway surface 2a of the bearing to generate abnormal noise such as tapping noise and vibration noise, and also cause an increase in bearing torque.

  In particular, when used in a CT scanner device, this kind of unusual noise may give stress to a subject, so that it is strongly desired to reduce the level of occurrence of unusual noise. Further, when the rolling element of the retainer 4 is the ball 3, the gap between the ball 3 and the pole 3 is reduced due to the contraction deformation of the pocket 5c, so that the pole 3 is easily restrained in the pocket 5c. As a result, the bearing torque increases. Will do.

  In view of the above-mentioned problems, the present invention eliminates the fitting structure (fitting portion) between segments, prevents contact between adjacent segments, and improves the workability of the rolling bearing. A cage and a rolling bearing using such a cage are provided.

  The cage for a rolling bearing according to the present invention is formed in a ring shape with at least two arc-shaped segments, and each arc-shaped segment has a pocket arranged at a predetermined pitch along a circumferential direction. Each of the opposing surfaces of the segments adjacent to each other along the circumferential direction has a flat surface shape, and is formed in a ring shape with a gap formed between the opposing surfaces of the opposing segments. Is what it is.

  According to the roller bearing retainer of the present invention, the connecting fitting portion is not formed between the circumferentially adjacent segments, and the circumferentially adjacent segments are not connected via the fitting portion. .

  Between the opposing surfaces, pockets may be formed in cooperation with the opposing segments.Each pocket is opened on one side in the axial direction, and a pair of claws are arranged on both sides of the opening. It can be a crown holder made of resin.

  The rolling bearing of the present invention uses the bearing retainer. When such a bearing retainer is used, there is no need to connect segments adjacent in the circumferential direction, so that the retainer can be incorporated into the bearing without assembling it in a ring (ring shape).

  The rolling bearing can be used in a CT scanner device.

  In the present invention, since there is no coupling fitting portion in each segment, the shape of each segment is simplified, the molding cost is reduced, the degree of freedom of the selected material is increased, and the design is facilitated. Further, the assembly can be incorporated into the bearing without assembling into a ring (ring shape), and the assembling property can be improved. Since there is no connecting fitting portion, the number of rolling elements (balls) can be increased by using a space for providing the fitting portion. That is, when a bearing having the same dimensions as a bearing using a segment having a fitting portion is configured, the number of rolling elements (balls) can be increased. In addition, contact between the segments can be avoided, and deformation of the segments, generation of vibration noises between the segments, and an increase in the torque of the bearing due to contact between the segments and the raceway surfaces of the inner ring and the outer ring can be reduced.

It is a principal part simplified sectional view of the rolling bearing which concerns on this invention. It is a simplified diagram of a roller bearing cage according to the present invention. It is a principal part expanded sectional plan view of the expanded state of the segment which comprises the cage for rolling bearings concerning this invention. FIG. 4 is an enlarged cross-sectional plan view of a main part in an unfolded state in which a ball as a rolling element is fitted to the roller bearing retainer according to the present invention. 1 is a cross-sectional side view in which a ball as a rolling element is fitted to a rolling bearing retainer according to the present invention. It is a principal part simplified perspective view of a segment. FIG. 5 is a sectional view taken along line XX of FIG. 4. It is a simplified diagram of a CT scanner device using a rolling bearing according to the present invention. It is a principal part simplified sectional drawing of the conventional rolling bearing. It is a principal part perspective view of the retainer of the rolling bearing shown in FIG. It is a top view of the deployment state of the segment of the conventional cage. It is a principal part top view of the expanded state which shows the connection state of the segment of the conventional cage. FIG. 4 is a simplified diagram showing a state where a gap is formed in a fitting portion.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a rolling bearing according to the present invention. The rolling bearing includes an inner ring 21 having an inner rolling surface 21a formed on an outer diameter surface, an outer ring 22 having an outer rolling surface 22a formed on an inner diameter surface, Between a plurality of balls (balls) 23 as rolling elements rotatably interposed between the inner rolling surface 21a of the inner race 21 and the outer rolling surface 22a of the outer race 2, and between the inner race 21 and the outer race 22 The main part is composed of a resin-made crown-shaped retainer 24 that is arranged and holds each ball 23 at equal intervals in the circumferential direction.

  As shown in FIG. 2, the retainer 24 in this case includes a plurality of (two in the illustrated example) arc-shaped segments 25. The segment 25 has a plurality of pockets 26 arranged at a predetermined pitch along the circumferential direction, as shown in FIGS. That is, the segment 25 has an arc-shaped main body portion 27 in which the concave portions 26a are formed at a predetermined pitch, and a pair of claw portions 26b, 26b protruding from the opening ends of the concave portions 26a of the main body portion 27, The pocket 26 is formed by the pair of claw portions 26b, 26b facing the concave portion 26a.

The end surface (opposed surface) 25a of each segment 25 has a flat surface shape, a half concave portion 26a1 is formed, and a claw portion 26b1 is formed at an open end of the half concave portion 26a1. For this reason, when each segment 25 is arranged in an annular shape as shown in FIG. 2, as shown in FIGS. 3 and 4, between the segments 25, 25 adjacent in the circumferential direction, that is, the opposing surfaces 25a, A gap C of a predetermined size is formed between 25a. Then, the opposing surface 25a of one segment 25 and the opposing surface 25a of the other segment 25 are opposed to each other, so that a pair of half concave portions 26a1 and 26a
One pocket 26 is formed by one and a pair of claw portions 26b1, 26b1. A ball (ball) 23 is fitted into each pocket 26 as shown in FIG.

  The segment 25 of the retainer 24 may be made of a metal such as steel or a copper alloy, or may be made of a resin. In the case of resin, there are polyacetal, polyamide (nylon 6.6, nylon 4.6), fluororesin and the like, and these can be reinforced with glass fiber or carbon fiber for use.

  By the way, since the rolling bearing configured as described above can form a so-called ultra-thin type rolling bearing, it can be used, for example, in a CT scanner device as shown in FIG.

  In the CT scanner device, the X-rays generated by the X-ray tube device 31 are applied to a subject 34 via a wedge filter 32 for making the intensity distribution uniform and a slit 33 for limiting the intensity distribution. The X-rays that have passed through the subject 34 are received by a detector 35, converted into electric signals, and sent to a computer (not shown). Each component such as the X-ray tube device 31, the wedge filter 32, the slit 33, and the detector 35 is a substantially cylindrical rotating base 38 rotatably supported on a fixed base 37 via a rolling bearing 50 according to the present invention. And rotates around the subject 34 with the rotation of the rotating base 38. Then, the X-ray tube apparatus 31 and the detector 35 facing each other rotate around the subject 34 to obtain projection data covering all angles at any point in the examination section of the subject 34. , A tomographic image is obtained by a preprogrammed reconstruction program.

  According to the cage for rolling bearings of the present invention, a fitting portion for connection is not formed between the segments 25, 25 adjacent in the circumferential direction, and the segments 25, 25 adjacent in the circumferential direction are connected via the fitting portion. It is not linked. In the present invention, since there is no coupling fitting portion in each segment 25, 25, the shape of each segment 25, 25 is simplified, the molding cost is reduced, the degree of freedom of the selected material is increased, and the design is facilitated. Further, the assembly can be incorporated into the bearing without assembling into a ring (ring shape), and the assembling property can be improved. Since there is no connecting fitting portion, the number of rolling elements (balls) 23 can be increased by using a space for providing the fitting portion. That is, when a bearing having the same dimensions as the bearing using the segment 7 having the fitting portion is formed, the number of the rolling elements (balls) 23 can be increased. Further, contact between the segments 25 can be avoided, and deformation of the segments 25, generation of vibration noise between the segments 25, and an increase in the torque of the bearing due to contact between the segments and the raceway surfaces 21a, 22a of the inner ring 21 and the outer ring 22 can be prevented. Can be reduced.

  As described above, the embodiment of the present invention has been described. However, the present invention is not limited to the above embodiment, and various modifications are possible, provided that the number of the segments 25 of the retainer 24 is at least two. Good. Further, the number of pockets in each segment 25 can be arbitrarily changed. The size of the gap C between the end faces 25a1 and 25a1 of the segments 25 and 25 adjacent in the circumferential direction is arbitrary as long as the ball 23 is stored and the pocket 26 is formed between the end faces 25a1 and 25a1 as shown in FIG. Can be set to Although the balls 23 are illustrated as the rolling elements, rollers may be used. Further, the present invention is not limited to a single-row bearing in which the number of rows of rolling elements is one, but is also applicable to a double-row bearing in which two rows of rolling elements are arranged.

  By the way, since the rolling bearing according to the present invention can constitute a so-called ultra-thin type rolling bearing, it can be used for a CT scanner device as shown in FIG. 8, for example, but is limited to a CT scanner device as an application. Instead, it can be used for various other industrial machines and machine mechanisms.

23 Rolling elements (balls, balls)
24 Cage 25 Segment 25a Opposing surface 26 Pocket 26b Claw 50 Bearing C Clearance

Claims (5)

A rolling bearing retainer formed of at least two arc-shaped segments in an annular shape, and each arc-shaped segment has pockets arranged at a predetermined pitch along a circumferential direction,
Rolling bearings in which opposing surfaces of adjacent segments along the circumferential direction are each formed into a flat surface shape, and are formed in a ring shape with a gap formed between opposing surfaces of opposing segments. For cage.   The cage for a rolling bearing according to claim 1, wherein a pocket is formed between the opposing surfaces in cooperation with the opposing segments.   3. The rolling bearing according to claim 1, wherein each pocket is an opening at one side in the axial direction, and is a resin crown retainer having a pair of claws disposed on both sides of the opening. 4. Retainer.   A rolling bearing, comprising the rolling bearing retainer according to any one of claims 1 to 3.   The rolling bearing according to claim 4, wherein the rolling bearing is used in a CT scanner device.

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