JP2008223970A - Thrust bearing cage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thrust bearing cage for allowing smooth work for inserting rolling elements into pockets while preventing the fall of the rolling elements from the pockets, and for stably holding the rolling elements after inserted into the pockets while reducing internal stress during work to improve the durability. <P>SOLUTION: The annular thrust bearing cage holds the plurality of rolling elements 6 rollingly incorporated between bearing rings 2, 4 arranged opposing each other in a relatively rotatable manner, one by one in the pockets 10. The plurality of pockets are formed in the cage at predetermined intervals along the peripheral direction. In openings 10a, 10b on at least one side of each pocket, pawl protrusions 8d are provided which are formed by shrinking the diameters of the openings to be smaller than the diameters of the rolling elements for preventing the fall of the rolling elements from the pockets. The pawl protrusions each have a two-stage structure consisting of a first pawl portion 81 formed by protruding the peripheral edge of the opening and a second pawl portion 82 formed by protruding a pocket face 10s inside the first pawl portion. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a retainer for a thrust bearing, and in particular, while preventing the rolling element from falling out of the pocket, it is excellent in workability when inserting the rolling element into the pocket and reduces internal stress generated during the work. The present invention relates to a thrust bearing retainer that improves durability and enables stable holding of rolling elements after insertion of a pocket.

  Conventionally, various rolling bearings that rotatably support a predetermined rotating shaft are known, and the bearing type of the rolling bearing can be roughly divided into a radial bearing and a thrust bearing depending on the direction of a load to be applied. Furthermore, it can be classified as a ball bearing or a bearing depending on the type of rolling element. As an example, FIG. 2 shows a configuration of a thrust ball bearing (hereinafter simply referred to as a bearing) for mainly applying an axial axial load, and the bearing is disposed so as to be relatively rotatable. A pair of race rings 32, 34, a plurality of rolling elements (balls) 36 incorporated so as to freely roll between the race rings 32, 34, and the rolling elements (balls) 36 are rotated one by one into the pocket 38. A holder 30 is provided for holding freely.

  By the way, in such a bearing, in order to perform the assembly operation smoothly, and in order to stabilize the rotational posture of the rolling element (ball) 36 in the pocket 38 during the rotating operation, the rolling element ( Ball) 36 needs to be prevented from falling out of pocket 38. For this reason, for example, Patent Document 1 discloses a cage that prevents a rolling element (ball) from falling out of a pocket by providing a claw-shaped protrusion (hereinafter referred to as a claw-shaped protrusion) on the periphery of the opening of the pocket. The configuration is disclosed as an example.

  Specifically, as shown in FIGS. 3 (a) and 3 (b), the retainer 40 is formed by forming a synthetic resin flat plate in an annular shape, and is predetermined along the circumferential direction of the side surface thereof. A plurality of through holes (i.e., pockets) 48 are provided at intervals, and claw-like protrusions 40d are provided on the peripheral edges of the openings 48a and 48b on both sides of the pocket 48 (the vertical direction in FIG. 5B). . In this case, two pairs of four claw-shaped projections 40d are provided on the peripheral edges of the openings 48a and 48b, and the pair of claw-shaped projections 40d are opposed to each other along the circumferential direction of the cage 48. And the other pair of claw-like projections 40d are positioned so as to face each other in the radial direction, and the cage 48 is configured.

The claw-like projection 40d has a diameter of the openings 48a and 48b of the pocket 48 reduced so that the opening 48a is smaller than a diameter of a rolling element (ball (not shown)) (hereinafter referred to as a ball diameter). , 48b projecting from the peripheral edge by a predetermined size (hereinafter, the size of the protrusion is referred to as a squeeze allowance).
When the rolling element (ball) is inserted into the pocket 48 of the cage 40, the claw-like projection 40d on one side of the pocket 48 (for example, the upper side in FIG. 3B) is expanded in the direction in which the opening 48a is enlarged. While elastically deforming and applying a pressing force to the other side of the pocket 48 (for example, the lower side of FIG. 3B) against the rolling element (ball), the rolling element (ball) is made to have a claw-like projection on the other side. Push into pocket 48 until it abuts against 40d.

Then, the elastically deformed one-side claw-like projection 40d returns to the original state (that is, the opening 48a is returned from the enlarged diameter state to the original state), so that the one-side claw-like projection 40d and the other-side claw-like projection 40d The rolling elements (balls) inserted into the pockets 48 by the claw-like projections 40d are sandwiched, and the cage 40 rotatably holds the rolling elements (balls) in a state where the posture is stabilized.
By providing the claw-like projections 40d on the cage 40 in this way, the rolling elements (balls) inserted into the pockets 48 are prevented from falling off.
Japanese Utility Model Publication No. 6-87721

  However, in the configuration of the retainer 40 as described above, in order to prevent the rolling elements (balls) from falling off, the claw-like projections 40d are set with a large allowance, and the claw-like projections 40d allow the pockets 48a, 48a, It is necessary to configure beforehand that 48b has a diameter sufficiently smaller than the ball diameter.

  Therefore, when the rolling element (ball) is inserted into the pocket 48, the claw-like protrusion 40d must be elastically deformed greatly in the direction in which the opening (for example, the opening 48a) is expanded. Therefore, the internal stress acts on the root portion of the claw-like projection 40d. Further, the pressing force (pushing force) required for inserting the rolling elements (balls) into the pocket 48 is increased, and the internal stress corresponding to the pressing force (pushing force) is also concentrated on the root portion of the claw-like protrusion 40d. Works.

  For this reason, when inserting the rolling elements (balls) into the pocket 48, work is performed with great care so that the internal stress does not cause damage such as cracks to the claw-like projections 40d, particularly the roots thereof. As a result, the workability (working efficiency) is greatly reduced, and as a result, the productivity of the bearing is deteriorated.

  Further, since a large pressing force (pushing force) acts on the rolling elements (balls) when inserted into the pocket 48, the surface may be scratched. In this case, the rolling elements (balls) However, it may not be possible to stably roll between the raceway surfaces of the bearing rings, and it may be difficult to keep the bearings rotating stably and satisfactorily over a long period of time.

  The present invention has been made to solve such a problem, and the object thereof is to enable smooth insertion of the rolling element into the pocket while preventing the rolling element from falling out of the pocket. Another object of the present invention is to provide a thrust bearing retainer that can improve the durability by relaxing internal stress generated during the operation and can stably hold the rolling elements after the pocket is inserted.

In order to achieve such an object, the thrust bearing retainer of the present invention has an annular shape, and includes a plurality of rolling elements that are rotatably incorporated between race rings arranged opposite to each other so as to be relatively rotatable. One pocket is held rotatably. In such a thrust bearing retainer, a plurality of the pockets are perforated at predetermined intervals along the circumferential direction of the retainer, and at least one side opening of each pocket prevents the rolling elements from dropping from the pocket. For this purpose, a claw-like projection formed by reducing the diameter of the opening with respect to the diameter of the rolling element is provided, and the claw-like projection includes a first claw portion that has a protruding peripheral edge of the opening. The second claw portion has a two-step structure in which the pocket surface inside the first claw portion protrudes in a convex shape.
As a result, the workability when inserting the rolling element into the pocket is significantly improved while preventing the falling of the rolling element from the pocket, and the internal stress generated during the work is remarkably relieved, thereby maintaining the durability of the cage. It is possible to improve the performance. Moreover, the rolling element after pocket insertion can be stably hold | maintained, and the said rolling element can be smoothly rotated over a long period in a pocket.

In this case, the opening of the pocket is provided with a plurality of claw-like projections having a part of the opening smaller than the diameter of the rolling element with a predetermined phase difference along the circumferential direction of the opening. Just do it.
As an example, the claw-shaped projections are configured as a pair, and one claw-shaped projection forming the pair is provided with a phase difference of 180 ° along the circumferential direction of the opening with respect to the other claw-shaped projection. it can.
At this time, for example, the pair of claw-shaped projections may be positioned along the circumferential direction of the cage, or the pair of claw-shaped projections may be positioned along the radial direction of the cage.
This makes it possible to smoothly insert the rolling element into the pocket while preventing the rolling element from falling out of the pocket with the minimum necessary claw-like projections, and to stabilize the rolling element after inserting the pocket. Can be held.

  The thrust bearing retainer can be made of various materials, but is preferably made of a predetermined resin material. Thereby, when inserting a rolling element into a pocket, a nail | claw-shaped processus | protrusion can be easily elastically deformed in the direction which expands the opening of a pocket.

  According to the thrust bearing cage of the present invention, the claw-like projections of the pocket opening have a two-stage structure of the first claw portion and the second claw portion, so that the rolling element can be prevented from falling out of the pocket while being rolled. While improving workability at the time of inserting a moving body into a pocket, the internal stress which generate | occur | produces at the time of the said work can be remarkably eased, and the durability of a holder | retainer can be improved easily. Moreover, the rolling element after pocket insertion can be hold | maintained stably, and can be rotated smoothly over a long period in a pocket.

  Hereinafter, a thrust bearing retainer according to an embodiment of the present invention will be described with reference to the accompanying drawings. 1 (a) to 1 (c) show a thrust bearing retainer (hereinafter simply referred to as a retainer) 8 according to an embodiment of the present invention. ), A pair of bearing rings 2, 4 having a washer shape arranged to face each other so as to be relatively rotatable, and a plurality of rolling elements (balls) 6 incorporated so as to be able to roll between the bearing rings 2, 4. Are incorporated in a thrust ball bearing (hereinafter simply referred to as a bearing) A. In this case, the cage 8 is assembled between the race rings 2 and 4 in a state where the rolling elements (balls) 6 are rotatably held in the pockets 10 one by one. Rotate (revolve) with ball 6. As a result, the rolling elements (balls) 6 can smoothly roll between the races 2 and 4 without bringing the rolling surfaces into contact with each other. As a result, these rolling elements (balls) 6 This prevents an increase in rotational resistance, seizure, and the like due to friction caused by contact with each other.

In this embodiment, as an example, the upper raceway 2 shown in FIG. 1A is configured as a shaft raceway (inner ring) attached to a rotation shaft (not shown), and the lower raceway shown in FIG. It is assumed that the raceway ring 4 is configured as a housing raceway (outer ring) attached to a housing (not shown). In this case, the bearing A is configured as a single type thrust bearing in which only one row of rolling elements (balls) 6 is incorporated between the inner and outer rings 2 and 4, but a double structure in which the rolling elements (balls) 6 are incorporated in two rows. It is good also as a bearing. In addition, in the configuration shown in FIG. 1A, the shape of the race ring (outer ring) 4 is a plane seat shape as an example. However, for example, the shape may be a centering seat shape, and the alignment is further performed. A configuration in which a centering washer (not shown) is provided for the seat-shaped outer ring 4 may be adopted.
In this embodiment, a ball bearing is used as a rolling element, but various rollers (cylindrical rollers, tapered rollers, spherical rollers, etc.) are rolled according to the use conditions and purpose of the thrust bearing. It is good also as a bearing structure applied as a moving body.

  As shown in FIGS. 1 (a) to 1 (c), the cage 8 has an outer diameter that is substantially the same as the outer diameter of the inner and outer rings 2 and 4, and the inner diameter is larger than the inner diameter of the inner ring 2. Is slightly larger than the inner ring dimension of the outer ring 4 and is formed in a substantially flat plate shape. The cage 8 may be made of any material as a material depending on the use condition or purpose of use of the bearing A, and the material is not particularly limited. However, in this embodiment, a rolling element (ball) described later is used. ) Assume that the cage 8 is made of a predetermined resin so that it can be easily elastically deformed when inserted into the pocket 10 of 6). In this case, the cage 8 may be formed by an arbitrary method such as injection molding or mold molding.

  In the cage 8, a plurality of pockets 10 are perforated at a predetermined interval (for example, an equal interval) along the circumferential direction of the cage 8, and both sides of each pocket 10 (see FIGS. 1A and 1C). In order to prevent the rolling elements (balls) 6 from falling out of the pockets 10 in the upper and lower openings 10a and 10b, the openings 10a and 10b are provided with diameter dimensions (balls) of the rolling elements (balls) 6. Claw-like projections 8d each having a diameter smaller than the diameter (hereinafter referred to as a ball diameter) are provided. In the configuration shown in FIGS. 1A to 1C, the surface (hereinafter referred to as pocket surface) 10s has a concave curved surface in which the curvature radius is set substantially the same as the curvature radius of the rolling element 6 (ball). In addition, each pocket 10 is formed as a through-hole penetrating from one side of the pocket to the other side (from the upper side to the lower side of FIGS. 1A and 1C) so that the cross-sectional shape is circular. ing.

  As shown in FIG. 1C, the claw-like projection 8d has a two-step structure of a first claw portion 81 and a second claw portion 82, and the first claw portion 81 has a peripheral edge of the openings 10a and 10b. The second claw portion 82 is protruded in a convex shape in the reduced diameter direction, while the second claw portion 82 is located on the inner side of the first claw portion 81 (below the opening 10a shown in FIG. The upper pocket surface 10s protrudes in a convex shape in the direction of diameter reduction. In this case, the 1st nail | claw part 81 and the 2nd nail | claw part 82 have comprised substantially parallel, The said 1st nail | claw part 81 and the 2nd nail | claw part 82 are provided in the base part along the pocket surface 10s. Are connected to each other in succession to a groove (hereinafter referred to as a claw portion connecting groove) 83 formed in a concave shape with a predetermined depth so as to be parallel to each other.

  The projecting size of the first claw portion 81 and the second claw portion 82 (hereinafter referred to as a crimping allowance) is arbitrarily set according to the size of the pocket 10 or the size of the rolling element (ball) 6. Therefore, there is no particular limitation here. For example, the interference allowance of the first claw part 81 and the interference allowance of the second claw part 82 may be set to the same size to form the claw-shaped protrusion 8d, or set to different sizes. You may comprise the nail | claw-shaped protrusion 8d. Furthermore, when setting these interference allowances to mutually different sizes, the interference allowance of the first claw portion 81 may be set smaller than the interference allowance of the second claw portion 82, or conversely the first claw portion The interference allowance of 81 may be set larger than the interference allowance of the second claw portion 82.

  In any case, the claw-like protrusion 8d has a two-stage structure of the first claw portion 81 and the second claw portion 82, so that the rolling elements (balls) 6 are removed from the pocket 10 in the first claw. Since it can prevent by both the part 81 and the 2nd nail | claw part 82, ie, it can prevent in two steps, these claw allowances are the nail | claw-shaped protrusion 40d (FIG. 3) of the conventional holder | retainer 40 mentioned above. As in (a) and (b)), it is not necessary to set the pocket opening so large that it is sufficiently smaller than the ball diameter. As a result, it is possible to smoothly insert the rolling elements (balls) 6 into the pockets 10 and to improve the workability (working efficiency).

  In the present embodiment, as an example, a case where the claw-like protrusion 8d is configured so as to have a two-stage structure in which the interference of the first claw portion 81 is set smaller than the interference of the second claw portion 82. Suppose. In other words, the claw-shaped protrusion 8d sets the first claw portion 81 to a margin for making the diameters of the openings 10a and 10b smaller than the ball diameter, and the second claw portion 82 of the first claw portion 81. It has a two-stage structure with a squeeze allowance larger than the squeeze allowance. Thereby, workability | operativity (working efficiency) at the time of the insertion operation | work to the pocket 10 of the rolling element (ball) 6 can be improved effectively, aiming at fall prevention from the pocket 10 of the rolling element (ball) 6. FIG.

  Here, the number of claw-shaped projections 8d (first claw portion 81 and second claw portion 82) provided for each opening 10a, 10b of the pocket 10 depends on the size of the cage 8, the size of the pocket 10, and the like. In order to prevent the rolling elements (balls) 6 from falling out of the pocket 10 by the claw-shaped projections 8d (the first claw portion 81 and the second claw portion 82), there is no particular limitation. It is preferable to provide at least two claw-like projections 8d (first claw portion 81 and second claw portion 82) at least in each of the openings 10a and 10b.

That is, in the openings 10a and 10b of the pocket 10, a plurality of (at least two) claw-like projections formed by reducing a part of the openings 10a and 10b smaller than the diameter (ball diameter) of the rolling element (ball). 8d (the first claw portion 81 and the second claw portion 82) may be provided with a predetermined phase difference along the circumferential direction of the openings 10a and 10b.
However, only one claw-like projection 8d (the first claw portion 81 and the second claw portion 82) may be provided in each of the openings 10a and 10b. In this case, the first claw portion 81 and the second claw portion 82 set to a predetermined interference allowance may be provided continuously over the entire circumference of each opening 10a, 10b, that is, in an annular shape.

  In the present embodiment, as an example, as shown in FIG. 1B, the claw-shaped protrusions 8d (the first claw portion 81 and the second claw portion 82) are configured as a pair, and the pair is One claw-shaped protrusion 8d formed is opposed to the other claw-shaped protrusion 8d with a phase difference of 180 ° along the circumferential direction of the openings 10a and 10b.

  Specifically, two pairs of claw-shaped projections 8d (first claw portion 81 and second claw portion 82) are provided in the openings 10a and 10b of the pocket 10, and among these, a pair of claw-shaped projections 8d (first claw-shaped projections 8d). The claw portion 81 and the second claw portion 82) are positioned facing each other along the circumferential direction of the cage 8, and the other pair of claw-shaped projections 8d (the first claw portion 81 and the second claw portion 82) are held. It is positioned so as to oppose the circumferential direction of the vessel 8. In other words, a total of four claw-like projections 8d (first claw portion 81 and second claw portion 82) are provided in the openings 10a and 10b of the pocket 10, and the four claw-like projections 8d are provided. (The first claw portion 81 and the second claw portion 82) are positioned two by two in the circumferential direction and the radial direction of the cage 10, and are equally spaced (90 ° in the circumferential direction of the openings 10a and 10b). Phase difference).

  Thus, in the configuration shown in FIG. 1B, as an example, the claw-like protrusions 8d (the first claw portion 81 and the second claw portion 82) are positioned along the circumferential direction and the radial direction of the cage 8. However, the arrangement positions of the claw-shaped protrusions 8d (the first claw part 81 and the second claw part 82) are not limited to the arrangements. For example, the four claw-shaped protrusions 8d (first claw part 8) shown in FIG. 81 and the second claw portion 82) may be arranged at positions rotated by a predetermined angle (for example, 45 ° or 30 °) clockwise or counterclockwise along the circumferential direction of each opening 10a, 10b. For example, in the case where three claw-shaped projections 8d (first claw portion 81 and second claw portion 82) are provided in the openings 10a and 10b of the pocket 10, the three claw-shaped projections 8d (first The claw portion 81 and the second claw portion 82) may be positioned at equal intervals (120 ° phase difference) along the circumferential direction of the openings 10a and 10b.

  In the configuration shown in FIG. 1B, the same number of claw-shaped protrusions 8d (first claw portion 81 and second claw portion 82) are positioned in the same phase with respect to all pockets 10 (openings 10a, 10b). However, the same number of claw-shaped protrusions 8d (the first claw portion 81 and the second claw portion 82) do not necessarily have to be positioned in the same phase with respect to all the pockets 10 (openings 10a, 10b). For example, the pocket 10 provided with four claw-like projections 8d (first claw portion 81 and second claw portion 82) and the three claw-like projections 8d (first claw portion 81 and second claw portion 82) are provided. The pockets 10 arranged alternately may be configured, or the two claw-like projections 8d (the first claw portion 81 and the second claw portion 82) are arranged so as to face each other in the circumferential direction of the cage 8. 10 and the two claw-like projections 8d (the first claw portion 81 and the second claw portion 82) may be alternately arranged with the pockets 10 arranged in the radial direction of the cage 8.

  Moreover, in this embodiment, as shown in FIG.1 (b), a pair of nail | claw-shaped protrusion 8d (1st nail | claw part 81 and 2nd nail | claw part 82) which opposes along the radial direction of the holder | retainer 8 is used. A constant radial thickness (distance in the radial direction) is provided between the openings 10a and 10b and the inner diameter portion of the cage 8, and between the openings 10a and 10b and the outer diameter portion of the cage 8.

  The size (dimension) of the radial thickness is not particularly limited here because it may be arbitrarily set according to the size of the cage 8, the size of the pocket 10, and the like. For example, as in the configuration shown in FIG. 1B, the radial thicknesses of the claw-shaped projections 8d (the first claw portion 81 and the second claw portion 82) are set to the openings 10a and 10b and the inner diameter portion of the cage 8 and the outside. You may set to a dimension smaller than the space | interval with a diameter part, or you may set the said radial direction thickness so that the said space | interval may be comprised substantially. Further, the radial thickness of the claw-like projection 8d (the first claw portion 81 and the second claw portion 82) may be a constant size as shown in FIG. It is good.

  On the other hand, the pair of claw-shaped protrusions 8d (the first claw portion 81 and the second claw portion 82) that face each other along the circumferential direction of the cage 8 are formed between the two pockets 10 adjacent to each other in the circumferential direction of the cage 8. It is provided with a circumferential thickness (distance in the circumferential direction) that is substantially the same as the interval, and claw-like projections 8d (the first claw portion 81 and the second claw portion) for these pockets 10 between the adjacent pockets 10. 82) are integrated. In this case, the claw-like projections 8d (the first claw portion 81 and the second claw portion 82) are formed such that a part of the openings 10a and 10b of the two pockets 10 adjacent to each other in the circumferential direction of the cage 8 is larger than the ball diameter. The diameter is reduced.

  Note that the size (dimension) of the circumferential thickness is not particularly limited because it may be arbitrarily set according to the size of the cage 8, the number of pockets 10, and the like. For example, as in the configuration shown in FIG. 1B, the circumferential thickness of the claw-shaped protrusions 8d (the first claw portion 81 and the second claw portion 82) is set to the two pockets 10 adjacent to each other in the circumferential direction of the cage 8. The circumferential thickness may be set to a dimension that is substantially the same as the interval, or smaller than the dimension, and the circumferential claw-shaped protrusions 8d (the first claw part 81 and the second claw part 82) with respect to the adjacent pockets 10 are set. ) May be configured as a separate structure. In this case, the claw-like protrusions 8d (the first claw portion 81 and the second claw portion 82) in the circumferential direction with respect to the adjacent pockets 10 may be arranged to face each other with a predetermined interval.

  Further, the circumferential width (distance in the circumferential direction of the openings 10a and 10b) of the claw-shaped projections 8d (first claw portion 81 and second claw portion 82) is the size and number of the pockets 10 (openings 10a and 10b). Since it may be set arbitrarily according to the above, there is no particular limitation. For example, a configuration in which two pairs of claw-like projections 8d (first claw portion 81 and second claw portion 82) are provided for each opening 10a, 10b as in this embodiment, that is, four claw-like projections 8d ( When the first claw part 81 and the second claw part 82) are provided in the openings 10a and 10b, the circumferential distance (peripheral length) of the openings 10a and 10b is smaller than the dimension divided into four equal parts. What is necessary is just to comprise each claw-like protrusion 8d (the 1st nail | claw part 81 and the 2nd nail | claw part 82) by the dimension (circumferential width).

  Further, the shape of the claw-like projections 8d (the first claw portion 81 and the second claw portion 82) is designed to smoothly insert the rolling elements (balls) 6 into the pockets 10, and after the insertion, the rolling elements (balls). ) In order to smoothly rotate the inside of the pocket 10 without dropping the pocket 10 from the pocket 10, a contact portion with the rolling element (ball) 6 is curved along the surface of the rolling element (ball) 6 (the surface). (A concave curved surface having a radius of curvature that is slightly larger than the radius of curvature). At this time, the claw-like projections 8d (the first claw portion 81 and the second claw portion 82) are preferably configured such that their longitudinal cross-sectional shapes (contours) are smooth and gently curved.

Here, when the rolling element (ball) 6 is inserted into the pocket 10 in the cage 8 having such a configuration, the following procedure is performed.
In this case, first, the rolling elements (balls) 6 are placed on the claw-like protrusions 8d on one side of the pocket 10 (for example, the opening 10a side (the upper side in FIG. 1C)), specifically, the first claw portion 81. In this state, a pressing force is applied to the rolling element (ball) 6 toward the other side of the pocket 10 (for example, toward the opening 10b side (the lower side of FIG. 10C)). As described above, since the claw portion connecting groove 83 is provided in the root portion of the first claw portion 81, the claw portion connecting groove 83 is deformed (specifically, enlarged deformation), so that the first claw portion connecting groove 83 is deformed. The one claw portion 81 can be easily elastically deformed in the direction in which the opening 10a is expanded. At that time, the internal stress generated in the claw-like protrusion 8d (first claw portion 81) with respect to the pressing force (elastic deformation force) causes the claw portion connecting groove 83 to be deformed (specifically, enlarged deformation). In addition to being relaxed by acting as a force for this purpose, it does not act intensively on the first claw portion 81 of the claw-like projection 8d, but acts on the entire claw-like projection 8d.

  Next, using the elastically deformed first claw portion 81 as a guide, the rolling element (ball) 6 is applied to the second claw portion 82 on the opening 10a side (upper side of FIG. 1C) (FIG. 1C). Dotted line state). In this state, a further pressing force is applied to the rolling element (ball) 6 toward the other side of the pocket 10 (for example, the lower side of FIG. 3C). At this time, as in the case of the first claw portion 81 described above, the claw portion connecting groove 83 is provided in the root portion of the second claw portion 82, and therefore the claw portion connecting groove 83 is deformed (specifically, The second claw portion 82 can be easily elastically deformed in the direction in which the diameter of the opening 10a is increased. Further, the internal stress generated in the claw-like projection 8d (second claw portion 82) with respect to the pressing force (elastic deformation force) causes the claw portion connecting groove 83 to be deformed (specifically, reduced deformation). This action is alleviated by acting as a force, and does not act intensively on the second claw portion 82 of the claw-like projection 8d, but acts on the whole claw-like projection 8d.

  And with respect to the rolling element (ball) 6 applied to this 2nd nail | claw part 82, the said rolling element (ball) 6 is the nail | claw-shaped protrusion 8d of the other side (for example, lower side of FIG.1 (c)). Specifically, the pressing force is continuously applied until it comes into contact with the second claw portion 82, and the rolling element (ball) 6 is pushed into the pocket 10 so that the surface thereof is along the pocket surface 10s, whereby the insertion operation is completed. (The state shown in FIG.

  When the rolling elements (balls) 6 are pushed into the pocket 10 in this way (that is, inserted), the claw-like protrusions 8d on one side (opening 10a side (upper side of FIG. 1 (c))) elastically deformed, Specifically, the first claw portion 81 and the second claw portion 82 return to the original state (that is, the opening 10a returns from the expanded state to the original state). As a result, the rolling elements (balls) 6 are inserted into the pockets 10. The retainer 8 and the rolling element (ball) 6 are integrated with each other. That is, the cage 8 includes the second claw portion 82 on one side (opening 10a side (upper side of FIG. 1C)) and the second side (opening 10b side (lower side of FIG. 1C)). The rolling elements (balls) 6 inserted into the pocket 10 can be held by the two claw portions 82, and the rolling elements (balls) 6 are rotatably held in the pocket 10 in a state where the posture is stabilized. be able to.

  In this state, the rolling elements (balls) 6 held in the pocket 10 have a first claw portion 81 on one side (opening 10a side (upper side in FIG. 1C)) and the other side (opening 10b side). No contact is made with any of the first claw portions 81 in FIG. Therefore, the rolling elements (balls) 6 held in the pocket 10 are not excessively contacted (clamped) by the claw-shaped protrusions 8d (first claw portions 81), and the rolling elements (balls) 6 are inserted into the pockets. 10 can be rotated smoothly.

  In this case, the rolling element (ball) 6 inserted into the pocket 10 is clamped by the second claw portion 82 whose diameter is set smaller than the ball diameter (set to a predetermined interference allowance). The rolling element (ball) 6 can sufficiently counteract (absorb the falling energy) to try to drop the rolling element (ball) 6 out of the pocket 10 and the rolling element (ball) 6 drops from the pocket 10. Can be prevented. As a result, the rolling elements (balls) 6 can be stably held in the pocket 10 for a long period of time, and the rolling elements (balls) 6 can be smoothly rotated.

  Even if the rolling element (ball) 6 comes off (over) the second claw portion 82, the force (dropping energy) for dropping the rolling element (ball) 6 from the pocket 10 is Most of the water is absorbed when the second claw part 82 is disengaged (overrides), and is left by the first claw part 81 whose diameter is set smaller than the ball diameter (set to a predetermined interference allowance). Is also absorbed, and it is possible to reliably prevent the rolling element (ball) 6 from falling out of the pocket 10.

  Further, in such insertion work, the claw portion connecting groove 83 deforms (specifically, enlarges) the internal stress generated during the elastic deformation of the claw-like protrusion 8d (the first claw portion 81 and the second claw portion 82). The claw-like projection 8d (the first claw portion 81 and the second claw portion) can be mitigated by being deformed or contracted) and effectively avoiding the concentration of the internal stress. 82) can be prevented from being damaged such as cracks.

  In addition, the claw-like protrusion 8d (the first claw portion 81 and the second claw portion 82) can be easily elastically deformed in the direction in which the opening (for example, the opening 10a) is expanded, and the first claw portion. By supporting the rolling element (ball) 6 at the time of insertion with the second claw portion 82 using 81 as a guide, the posture can be stabilized. Therefore, the insertion work of the rolling element (ball) 6 into the pocket 10 is very difficult. It can be done smoothly.

  Furthermore, as described above, the claw-like protrusion 8d has a two-step structure of the first claw portion 81 and the second claw portion 82, so that the rolling element (ball) 6 is prevented from dropping from the pocket 10 in the first claw portion 81. In addition, the second claw portion 82 can prevent it in two stages. For this reason, these interference allowances do not have to be set as large as the conventional configuration (so that the openings 10a and 10b have a diameter sufficiently smaller than the ball diameter), and the first claw portion 81 and the second claw It is possible to set the interference of the portion 82 to be relatively small, and the workability (working efficiency) when the rolling elements (balls) 6 are inserted into the pocket 10 can be significantly improved.

  As a result, the pressing force when inserting the rolling element (ball) 6 into the pocket 10 can be small, and for example, it is possible to effectively prevent the surface of the rolling element (ball) 6 from being damaged, The rolling element (ball) 6 can be accurately rotated over a long period of time.

As described above, according to the cage 8 according to the present embodiment, specifically, the claw-like projections 8d of the openings 10a and 10b of the pocket 10 are formed in a two-stage structure including the first claw portion 81 and the second claw portion 82. As a result, the workability (working efficiency) when inserting the rolling element (ball) 6 into the pocket 10 is remarkably improved while reliably preventing the rolling element (ball) 6 from falling out of the pocket 10. The internal stress generated during the operation can be remarkably eased, and the durability of the cage 8 can be easily improved.
Further, the rolling element (ball) 6 after being inserted into the pocket 10 can be stably held, and the rolling element (ball) 6 can be smoothly rotated in the pocket 10 over a long period of time.
Therefore, by adopting a bearing configuration in which the rolling elements (balls) 6 are held by the cage 8, the bearing A can be stably and satisfactorily rotated over a long period of time with a constant accuracy.

It is a diagram showing a configuration example of a thrust bearing retainer according to an embodiment of the present invention, (a) is a cross-sectional view of the thrust bearing in a state in which the thrust bearing retainer is incorporated, (b), FIG. 4C is a partial plan view of a thrust bearing cage for explaining the configuration of the claw-shaped projections, and FIG. 5C is a partial cross-sectional view of the thrust bearing cage for explaining the configuration of the claw-shaped projections. Sectional drawing which shows the structural example of the conventional thrust ball bearing. It is a figure which shows the structural example of the conventional cage for thrust bearings, Comprising: (a) is a fragmentary top view, (b) is a fragmentary sectional view.

Explanation of symbols

2 Inner ring 4 Outer ring 6 Rolling element (ball)
8 Cage 8 d Claw-like projection 10 Pocket 10 a, 10 b Opening 10 s Pocket surface 81 First claw part 82 Second claw part 83 Claw part connecting groove A Thrust ball bearing

Claims (6)

An annular thrust bearing retainer that rotatably holds a plurality of rolling elements that are rotatably incorporated between raceways arranged opposite to each other so as to be relatively rotatable,
A plurality of the pockets are perforated at predetermined intervals along the circumferential direction of the cage, and at least one side of each pocket is provided with the opening to prevent the rolling element from dropping from the pocket. A claw-like projection formed by reducing the diameter of the moving body is provided.
The claw-like projection has a two-step structure of a first claw portion that protrudes in a convex shape at the periphery of the opening and a second claw portion that protrudes in a convex shape on the pocket surface inside the first claw portion. A thrust bearing retainer characterized by comprising:   The pocket opening is provided with a plurality of claw-like projections, each of which has a smaller diameter than the diameter of the rolling element, with a predetermined phase difference along the circumferential direction of the opening. The cage for a thrust bearing according to claim 1.   The claw-shaped projections are configured in pairs, and one claw-shaped projection forming the pair is provided with a phase difference of 180 ° along the circumferential direction of the opening with respect to the other claw-shaped projection. The thrust bearing retainer according to claim 2, wherein the retainer is a thrust bearing retainer.   4. The thrust bearing retainer according to claim 3, wherein the pair of claw-shaped projections are positioned along a circumferential direction of the retainer.   The thrust bearing retainer according to claim 3, wherein the pair of claw-shaped protrusions are positioned along a radial direction of the retainer.   The thrust bearing retainer according to any one of claims 1 to 5, wherein the retainer is made of a predetermined resin material.

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