Retainer for ball bearing

Abstract

To provide a retainer for a ball bearing which achieves good balance of the retainer, attains stable rotation, and can be handled in a state that balls and the retainer are integrally assembled.SOLUTION: A retainer for a ball bearing includes: a plurality of columnar parts 20 disposed at intervals in a circumferential direction and each including holding surfaces 21a, 21b on both side surfaces in the circumferential direction; and connection parts 30A, 30B each of which connects the columnar parts 20 located adjacent to each other in the circumferential direction at one axial side or the other axial side. First and second pockets 50, 51 are alternately disposed in the circumferential direction so as to be point-symmetric with respect to a radial axis passing through a center of the columnar part 20. The first and second pockets 50, 51 have pairs of first and second overlap allowance parts 55, 56 which protrude so as to come close to each other in the circumferential direction at opening ends of first and second opening parts 52, 53 which are open in an axial direction. A distance W1 between the first overlap allowance parts 55 and a distance W2 between the second overlap allowance parts 56 are smaller than a diameter D of a ball 40.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cage for a ball bearing. [Background technology]

[0002] For example, a ball bearing such as a deep groove ball bearing has a plurality of balls rotatably held by a cage disposed between an outer ring raceway and an inner ring raceway.

[0003] The ball bearing cage described in Patent Document 1 is composed of a single annular body in which multiple axially recessed pockets are formed at intervals in the circumferential direction. When this cage is divided into two units in the axial direction on a plane including the center of each ball, the two units have the same volume.

[0004] Patent Document 2 discloses a ball bearing equipped with an S-shaped retainer having a number of column sections spaced apart along the circumferential direction and connecting sections arranged alternately in pockets on one axial side and the other, connecting adjacent column sections in the circumferential direction. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2011-169368 A [Patent Document 2] JP 2016-121712 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, although the ball bearing in Patent Document 1 makes the bearing internal space on both axial sides equal, allowing the lubricant to be evenly sealed on both axial sides, and aims to suppress leakage of the lubricant without reducing the amount of lubricant, the cage shape is asymmetric on both axial sides, so the fluidity of the lubricant differs on both axial sides, and there is a risk of the lubricant being biased to one side in the axial direction. Also, the ball bearing in Patent Document 2 makes the cage pockets S-shaped to achieve both ease of assembly and prevention of the cage falling off, but because the cage cannot hold the balls, there is a problem in that the balls and cage cannot be handled in a state where they are assembled together.

[0007] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a retainer for a ball bearing in which the retainer shape is symmetrical on both axial sides, thereby achieving good balance and stable rotation, and which can be handled in a state in which the balls and retainer are assembled together. [Means for solving the problem]

[0008] Therefore, the above object of the present invention is achieved by the following configuration [1] of a cage for a ball bearing. [1] A cage for a ball bearing having a plurality of pockets that rotatably hold balls as rolling elements, A plurality of pillars arranged at intervals in a circumferential direction and having holding surfaces on both circumferential sides thereof for holding the balls; A connecting portion that connects the circumferentially adjacent column portions to each other on one axial side or the other axial side in the circumferential direction; Equipped with The plurality of pockets include: a first pocket defined by the retaining surfaces of the column portions adjacent to each other in the circumferential direction and a side surface of the connecting portion on one axial side facing the other axial side; a second pocket defined by the retaining surfaces of the column portions adjacent to each other in the circumferential direction and a side surface of the connecting portion on the other axial side facing the one axial side; are arranged alternately in the circumferential direction and point-symmetrically about a radial axis passing through the center of the column portion, The first pocket has a first opening that opens to the other axial side, The second pocket has a second opening that opens to one side in the axial direction, The first opening is provided with a pair of first engagement portions that protrude toward each other in a circumferential direction, The second opening is provided with a pair of second engagement portions that protrude toward each other in the circumferential direction, a distance between the pair of first contact portions is smaller than a diameter of the ball; The distance between the pair of second engagement portions is smaller than the diameter of the ball. Cage for ball bearings. Effect of the Invention

[0009] According to the ball bearing retainer of the present invention, the retainer shape is symmetrical on both axial sides, which provides good balance and stable rotation, and the balls and retainer can be easily handled when assembled together. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a partial perspective view of a cage according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a development view showing the shape of pockets in the cage of FIG. 1 as viewed from a radial direction. [Diagram 3] FIG. 3 is a cross-sectional view of a cage that holds balls disposed between an outer ring raceway and an inner ring raceway. [Figure 4] 4(a) to (c) are cross-sectional views of a cage that holds balls arranged between an outer ring raceway and an inner ring raceway in a modified example, and are views for explaining an assembly process. [Diagram 5] FIG. 5 is a perspective view showing a state in which balls are fitted into pockets of the cage shown in FIG. [Figure 6] FIG. 6 is a partial perspective view of a cage according to a second embodiment of the present invention. [Figure 7] FIG. 7 is a development view showing the shape of pockets in the cage of FIG. 6 as viewed from a radial direction. [Figure 8] FIG. 8 is a partial perspective view of a cage according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a ball bearing cage according to the present invention will be described in detail with reference to the drawings. (First embodiment) FIG. 1 is a perspective view of a ball bearing cage according to a first embodiment of the present invention, FIG. 2 is a development showing the shape of a pocket, and FIG. 3 is a vertical sectional view of the ball bearing.

[0012] The ball bearing cage (hereinafter also simply referred to as cage) 10 of this embodiment includes a plurality of columnar sections 20 formed in a substantially cylindrical shape and arranged at predetermined intervals in the circumferential direction, and a plurality of connecting sections 30 that connect circumferentially adjacent columnar sections 20 on one axial side or the other axial side. The cage 10 is formed of an elastic resin such as nylon 66, nylon 46, polyether ether ketone, polyphenylene sulfide, or phenol, and the plurality of columnar sections 20 and the plurality of connecting sections 30 are alternately arranged in the circumferential direction, forming a bellows shape symmetrical on both axial sides.

[0013] Each pillar portion 20 has a spherical holding surface 21a formed on one circumferential side surface, and a spherical holding surface 21b formed on the other circumferential side surface.

[0014] Each connecting portion 30 connects the cylindrical surfaces 22 of the column portions 20 adjacent in the circumferential direction alternately on one axial side and the other axial side in the circumferential direction.

[0015] On the inner surface (side surface facing the other axial side) of the connecting portion 30 on one axial side, a spherical holding surface 31a is formed smoothly continuing to the holding surfaces 21a, 21b of the pair of column portions 20, and on the inner surface (side surface facing one axial side) of the connecting portion 30 on the other axial side, a spherical holding surface 31b is formed smoothly continuing to the holding surfaces 21a, 21b of the pair of column portions 20. In the following description, the connecting portion 30 on one axial side will also be referred to as connecting portion 30A, and the connecting portion 30 on the other axial side will also be referred to as connecting portion 30B.

[0016] In other words, the holding surfaces 21a, 21b of a pair of circumferentially adjacent column portions 20 and the holding surface 31a (the surface facing the other axial side) of the connecting portion 30A on one axial side define a first pocket 50. Furthermore, the holding surfaces 21a, 21b of a pair of circumferentially adjacent column portions 20 and the holding surface 31b (the surface facing one axial side) of the connecting portion 30B on the other axial side define a second pocket 51. The first pocket 50 and the second pocket 51 are arranged alternately in the circumferential direction.

[0017] The first pocket 50 and the second pocket 51 are formed point symmetrically about a radial axis passing through the center G of the column portion 20 (see Figure 2), and the inner diameter d of the first pocket 50 and the second pocket 51 is a spherical surface slightly larger than the diameter D of the ball 40, so that the ball 40 contained in the first and second pockets 50, 51 is held so as to be able to rotate smoothly.

[0018] The first pocket 50 has a first opening 52 that opens toward the other axial side, and the second pocket 51 has a second opening 53 that opens toward one axial side. A pair of inclined surfaces 54 that gradually open outward in the axial direction are formed at the opening ends of each of the first opening 52 and the second opening 53. The pair of inclined surfaces 54 act as guides when the balls 40, which will be described later, are inserted into the first pocket 50 and the second pocket 51.

[0019] In the first opening 52, a pair of first engagement portions 55, which are the intersections of the holding surfaces 21a, 21b of the pair of pillars 20 and the pair of inclined surfaces 54, are formed protruding toward each other in the circumferential direction. In addition, in the second opening 53, a pair of second engagement portions 56, which are the intersections of the holding surfaces 21a, 21b of the pair of pillars 20 and the pair of inclined surfaces 54, are formed protruding toward each other in the circumferential direction.

[0020] 2, the distance W1 between the pair of first overhanging portions 55 is slightly smaller than the diameter D of the ball 40, and the distance W2 between the pair of second overhanging portions 56 is slightly smaller than the diameter D of the ball 40. The distances W1 and W2 may be the same length or different lengths.

[0021] As shown in Figure 3, the retainer 10, which rotatably holds the balls 40 in the first pocket 50 and the second pocket 51, respectively, is disposed between the outer ring raceway 11a of the outer ring 11 and the inner ring raceway 12a of the inner ring 12 of the deep groove ball bearing 15.

[0022] For example, as shown in Figures 4(a) to 4(c), ball bearing 15 may be a four-point contact ball bearing in which inner ring 12 is separated into two. In this type of modified ball bearing 15, as shown in Figure 4(a), retainer 10 holding balls 40 is assembled onto outer ring raceway 11a by utilizing the elasticity of retainer 10. Then, as shown in Figures 4(b) and 4(c), divided bodies 12a and 12b constituting inner ring 12 are assembled from the left and right, so that it is disposed between outer ring raceway 11a and inner ring raceway 12a.

[0023] 5, balls 40 are assembled into the first pocket 50 and the second pocket 51 by being inserted axially into the first pocket 50 through the first opening 52 and into the second pocket 51 through the second opening 53. At that time, each ball 40 is guided by the inclined surface 54, which serves as a guide portion, and elastically deforms the cage 10 in the circumferential direction, widening the distances W1, W2 between the pair of first overhang portions 55 and the pair of second overhang portions 56 before being inserted into the first pocket 50 and the second pocket 51.

[0024] When the balls 40 are inserted into the first pocket 50 and the second pocket 51, the pair of first hook portions 55 and the pair of second hook portions 56 are elastically deformed and pushed apart in the circumferential direction, and when the balls 40 have been inserted into the first pocket 50 and the second pocket 51, they return to their original distances W1, W2 due to the elasticity of the cage 10. As a result, the balls 40 housed in the first pocket 50 and the second pocket 51 come into contact with the pair of first hook portions 55 and the pair of second hook portions 56, preventing them from falling out of the first pocket 50 and the second pocket 51.

[0025] As described above, according to the cage 10 of this embodiment, the first opening 52 and the second opening 53 of the first pocket 50 and the second pocket 51 are provided with a pair of first overhanging portions 55 and a pair of second overhanging portions 56, so that the balls 40 installed are unlikely to fall out of the first pocket 50 and the second pocket 51, and the balls 40 and the cage 10 can be easily handled in an assembled state, improving ease of handling and assembly. In addition, the opening ends of the first opening 52 and the second opening 53 are provided with inclined surfaces 54 that open in the axial direction as guide surfaces for the balls 40, so that the balls 40 can be easily installed in the first pocket 50 and the second pocket 51, improving assembly.

[0026] Furthermore, the retainer 10 has a plurality of pillars 20 and a plurality of connecting portions 30 (30A, 30B) that are alternately arranged in the circumferential direction and are symmetrically formed on both sides in the axial direction, resulting in good balance and stable rotation. Also, the retainer 10 has a plurality of pillars 20 and a plurality of connecting portions 30 that are continuously formed in a bellows shape, which allows elastic deformation in the circumferential direction and absorbs the circumferential displacement of the balls 40 that accompanies the rotation of the ball bearing 15, resulting in stable rotation. Also, when viewed from the circumferential direction, the first pockets 50 and the second pockets 51 and the connecting portions 30A, 30B are alternately arranged, which increases the fluidity of the lubricant sealed inside the bearing.

[0027] Second embodiment FIG. 6 is a perspective view of a ball bearing cage according to a second embodiment of the present invention, and FIG. 7 is a development showing the shape of a pocket. In the ball bearing retainer 10 of this embodiment, instead of the inclined surface 54 (see Figure 1) provided on the ball bearing retainer of the first embodiment, an R-chamfered portion 57 is provided at the opening ends of the first opening 52 and the second opening 53 of the first pocket 50 and the second pocket 51 as a guide portion for the balls 40. Other configurations and functions are similar to those of the ball bearing cage 10 of the first embodiment, so the same or corresponding reference numerals are used for the same parts, and the description will be simplified or omitted.

[0028] Third embodiment FIG. 8 is a perspective view of a main portion of a ball bearing cage according to a third embodiment of the present invention. In this embodiment, the ball bearing retainer 10 has a slit 58 formed approximately in the circumferential center of at least one of the multiple column portions 20, and the column portion 20 is separated into a column portion 20a on one circumferential side and a column portion 20b on the other circumferential side.

[0029] According to the ball bearing retainer 10 of this embodiment, the slits 58 provided in the column portions 20 provide cuts in the retainer 10, improving the circumferential freedom of the retainer 10 and relieving the tension force generated between the balls 40 and the first pocket 50 and second pocket 51, thereby suppressing wear of the retainer 10. Furthermore, even if the width of the slits 58 becomes zero due to thermal expansion or expansion due to water absorption, that is, even if both sides of the slits 58 come into contact, the bellows-like structure of the retainer 10 uniformly narrows the gaps between the balls 40 and the first pocket 50 and second pocket 51, thereby suppressing premature wear and temperature rise of the retainer 10 due to increased contact resistance, and preventing an increase in load torque, thereby extending the life of the retainer 10.

[0030] In the illustrated example, a gap is created in the retainer 10 by providing a slit 58 in one pillar portion 20, but the retainer 10 may be divided into two pieces by providing a slit 58 in each of two pillar portions 20, or the retainer 10 may be divided into n pieces by providing a slit 58 in each of n pillar portions 20 (n is a natural number).

[0031] In addition, in the above embodiment, a deep groove ball bearing has been described as an example, but the present invention can also be applied to other types of ball bearings, such as angular contact ball bearings and four-point contact ball bearings, with the same effects being achieved.

[0032] The present invention is not limited to the above-described embodiments, and can be modified and improved as appropriate.

[0033] As described above, the present specification discloses the following: (1) A cage for a ball bearing having a plurality of pockets for rotatably holding balls as rolling elements, A plurality of pillars arranged at intervals in a circumferential direction and having holding surfaces on both circumferential sides thereof for holding the balls; A connecting portion that connects the circumferentially adjacent column portions to each other on one axial side or the other axial side in the circumferential direction; Equipped with The plurality of pockets include: a first pocket defined by the retaining surfaces of the column portions adjacent to each other in the circumferential direction and a side surface of the connecting portion on one axial side facing the other axial side; a second pocket defined by the retaining surfaces of the column portions adjacent to each other in the circumferential direction and a side surface of the connecting portion on the other axial side facing the one axial side; are arranged alternately in the circumferential direction and point-symmetrically about a radial axis passing through the center of the column portion, The first pocket has a first opening that opens to the other axial side, The second pocket has a second opening that opens to one side in the axial direction, The first opening is provided with a pair of first engagement portions that protrude toward each other in a circumferential direction, The second opening is provided with a pair of second engagement portions that protrude toward each other in the circumferential direction, a distance between the pair of first contact portions is smaller than a diameter of the ball; The distance between the pair of second engagement portions is smaller than the diameter of the ball. Cage for ball bearings. With this configuration, the cage shape is symmetrical on both axial sides, resulting in good balance and stable rotation. In addition, the balls and cage are easily assembled, and the balls assembled in the pockets are prevented from falling out of the pockets by the pair of engagement portions, making the balls and cage easily handled when assembled together.

[0034] (2) The opening ends of the first opening and the second opening have guide portions for guiding the balls inserted into the pockets. A ball bearing retainer as described in (1). According to this configuration, the ball can be guided by the guide portion and inserted into the pocket, improving assembly ease.

[0035] (3) The guide portion is an inclined surface or a R-chamfered portion that gradually opens toward one axial side or the other axial side. A ball bearing retainer as described in (2). According to this configuration, the ball can be easily inserted into the pocket by being guided by the inclined surface or R-chamfered portion that opens in the axial direction, improving assembly ease.

[0036] (4) At least one of the plurality of column portions has a slit that separates the column portions in the circumferential direction. A ball bearing retainer as described in (1). According to this configuration, the slits provided in the pillar portions improve the circumferential freedom of the retainer, reduce the tension force generated between the balls and the pockets, and suppress wear of the retainer, etc. [Explanation of symbols]

[0037] 10 Cage for ball bearings 20, 20a, 20b pillar section 21a, 21b holding surface 30, 30A, 30B connection part 31a Retaining surface (side surface facing the other axial direction) 31b Retaining surface (side surface facing one axial direction) 40 balls (rolling elements) 50 1st pocket (pocket) 51 Second pocket (pocket) 52 First opening 53 Second Opening 54 Slope 55 First hook-up part 56 Second interlocking part 57 R chamfered part (guide part) 58 Slit D ball diameter W1 Distance between first overlapping parts W2 Distance between second overlapping parts

Claims

1. A ball bearing cage having a plurality of pockets for rotatably holding balls as rolling elements, comprising: A plurality of pillars arranged at intervals in a circumferential direction and having holding surfaces on both circumferential sides thereof for holding the balls; A connecting portion that connects the circumferentially adjacent column portions to each other on one axial side or the other axial side in the circumferential direction; Equipped with The plurality of pockets include: a first pocket defined by the retaining surfaces of the column portions adjacent to each other in the circumferential direction and a side surface of the connecting portion on one axial side facing the other axial side; a second pocket defined by the retaining surfaces of the column portions adjacent to each other in the circumferential direction and a side surface of the connecting portion on the other axial side facing the one axial side; are arranged alternately in the circumferential direction and point-symmetrically about a radial axis passing through the center of the column portion, The first pocket has a first opening that opens to the other axial side, The second pocket has a second opening that opens to one side in the axial direction, A pair of first engagement portions are provided in the first opening portion and protrude toward each other in a circumferential direction, The second opening is provided with a pair of second engagement portions that protrude toward each other in a circumferential direction, a distance between the pair of first engagement portions is smaller than a diameter of the ball; A distance between the pair of second engagement portions is smaller than a diameter of the ball. Cage for ball bearings.

2. The first opening and the second opening have guide portions at their open ends for guiding the balls inserted into the pockets.

2. The cage for a ball bearing according to claim 1.

3. The guide portion is an inclined surface or an R-chamfered portion that gradually opens toward one axial side or the other axial side.

3. The cage for a ball bearing according to claim 2.

4. At least one of the plurality of column portions has a slit that separates the column portions in a circumferential direction.

2. The cage for a ball bearing according to claim 1.

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