WO2022186094A1 - Rolling bearing and cage for rolling bearing - Google Patents

Abstract

A cage (6) comprises two annular bodies (10) overlapping each other in the axial direction. Each annular body (10) has a plurality of pocket wall portions (13) and a plurality of connecting plate portions (14). The cage (6) is provided with cutout portions (13a, 13b) in an inner diameter surface and an outer diameter surface of the pocket wall portion (13) such that a strip width (W1) or a radial dimension of the pocket wall portion (13) is smaller than a radial dimension (W2) of the connecting plate portion (14). In each pocket wall portion, the radial center of the strip width (W1) between a deepest part (P1) of the cutout portion (13a) in the inner diameter surface and a deepest part (P2) of the cutout portion (13b) in the outer diameter surface is set near the pitch circle diameter of a ball (5). The strip width (W1) is set to 35% or less of a diameter (BD) of the ball (5), and a circumferential range (L1) of each of the cutout portions (13a, 13b) is set to 50-100% of the diameter (BD) of the ball (5).

Description

Rolling bearings and cages for rolling bearings Related application

This application claims the priority of Japanese Patent Application No. 2021-035427 filed on March 5, 2021, and is incorporated herein by reference in its entirety.

The present invention relates to rolling bearings and rolling bearing retainers, and, for example, to techniques for reducing vibration and improving lubrication life in rolling bearings for motors and the like.

A synthetic resin retainer for use in rolling bearings has been proposed (Patent Document 1). This synthetic resin retainer consists of two annular bodies facing each other in the axial direction, and a plurality of pockets for accommodating balls are formed at intervals in the circumferential direction between the two annular bodies.
Also, in order to improve lubrication life, a rolling bearing has been proposed in which a circumferential groove-shaped grease pocket is formed on the inner diameter surface of the outer ring (Patent Document 2).

JP 2013-7468 A JP 2009-275176 A

In the conventional synthetic resin retainer Rt, as shown in FIGS. 6 and 7, the band width W, which is the radial dimension of the pocket portion Pt, is in the range of 40% to 50% of the ball diameter with the ball PCD as the center. It has a shape in which the ball 30 is held by . The band width W is 70% to 80% of the radial dimension D1 between the inner diameter surface of the outer ring 31 and the outer diameter surface of the inner ring 32 .

In this case, as shown in FIG. 6, the gap δ between the ball 30 and the inner diameter side edge of the pocket portion Pt and the gap δ1 between the ball 30 and the outer diameter side edge of the pocket portion Pt are widened. For this reason, less grease adhering to the ball surface is scraped off by the pocket portion Pt, and more grease is caught between the pocket portion Pt and the ball 30 . As a result, the shear resistance of the grease between the pocket portion Pt and the balls 30 increases, the behavior of the retainer Rt becomes unstable, and the vibration and noise values increase.

In addition, for rolling bearings used at high speeds where the dn value obtained by multiplying the inner diameter dimension dmm of the rolling bearing by the rotational speed n (min ^-1 ) is 350,000 or more, considering the heat generation, the static space volume is used as the upper limit of 100%. be done. The "static space volume" is the volume of the space (static space) excluding the rolling elements and cage in the bearing space between the inner and outer rings. When seal members are attached on both sides in the axial direction, the static space volume is the volume of the static space between the seal members on both axial sides in the bearing space between the inner and outer rings. A space in the bearing space that includes the rolling elements and the retainer is called a dynamic space.

After the bearing rotates, the grease is discharged from the dynamic space to the static space and held in the static space near the inner diameter side of the outer ring. The grease retained in the stationary space between the seal member below the ball PCD and the rear surface of the retainer and near the outer diameter of the inner ring is less likely to contribute to lubrication.
Since the band width W of the pocket portion Pt of the conventional product shown in FIG. As shown in Fig. 8, grease pockets 31b (Fig. 8) are provided on both sides in the axial direction of the raceway surface 31a on the inner diameter surface of the outer ring 31 for the purpose of improving the lubrication life. If it is increased, the manufacturing cost will increase.

An object of the present invention is to provide a rolling bearing and a rolling bearing retainer that can reduce vibration, improve lubrication life, and reduce manufacturing costs.

A rolling bearing according to the present invention comprises inner and outer rings, a plurality of balls interposed between the inner and outer rings, and a retainer having pockets for holding the respective balls. Each annular body includes a plurality of pocket wall portions that are arranged at regular intervals in the circumferential direction and each constitutes an inner wall surface of the pocket, and the pocket wall portions that are adjacent to each other in the circumferential direction. A rolling bearing having a plurality of coupling plate portions that are coupled, wherein the two annular bodies are overlapped and coupled to each other by the respective coupling plate portions,
The retainer has cutout portions on the inner diameter surface and the outer diameter surface of the pocket wall portion so that the band width, which is the radial dimension of the pocket wall portion, is smaller than the radial dimension of the coupling plate portion. provided respectively,
In each pocket wall, the center in the radial direction of the band width between the deepest part of the notch on the inner diameter surface and the deepest part of the notch on the outer diameter surface is near the pitch circle diameter of the ball,
The band width is 35% or less of the diameter of the ball, and the circumferential range of each notch is 50 to 100% of the diameter of the ball.
The vicinity of the pitch diameter of the ball is within a range of ±5% of the diameter of the ball based on the pitch diameter (PCD) of the ball.

According to this configuration, the grease adhering to the ball is scraped off by the notches on the inner diameter side and the outer diameter side of the pocket wall, respectively, so that the amount of grease caught between the pocket and the ball is reduced. As a result, shear resistance of the grease between the pocket and the balls is reduced, the behavior of the retainer is stabilized, and a remarkable effect is achieved that vibration and noise are reduced.
If the band width of the notch exceeds 35% of the diameter of the ball, or if the circumferential range of the notch is less than 50% of the diameter of the ball, less grease will be scraped off and the space between the pocket and the ball will be reduced. More grease gets caught. In this case, the behavior of the retainer is not stable, and the effect of suppressing vibration and noise is small.

A notch is provided on the outer diameter surface of the pocket wall, increasing the static space. In this case, the stationary space volume is increased compared to the case where the notch is provided only on the inner diameter surface of the pocket wall or the case where the pocket wall is not provided with the notch. By providing the cutout portion on the outer diameter surface of the pocket wall portion, the amount of grease retained increases in the static space on the inner diameter side of the outer ring. Therefore, it is possible to improve the lubrication life without providing a circumferential groove-like grease pocket or the like on the inner diameter surface of the outer ring. Therefore, the manufacturing cost can be reduced as compared with the conventional structure in which grease pockets are provided on the inner diameter surface of the outer ring.

In the case of only the notch on the inner diameter side, grease tends to be caught between the pocket and the balls from the outer diameter side where there is no notch, and the behavior of the retainer is difficult to stabilize, resulting in increased vibration and noise. In addition, the volume of the static space on the outer diameter side of the inner ring increases, and although the amount of grease retained in the static space on the outer diameter side of the inner ring increases, it is difficult to contribute to the lubrication of the rolling parts.
If there is only a notch on the outer diameter side, the amount of grease retained on the inner diameter side of the outer ring increases and the lubrication life is improved. It is difficult to stabilize the behavior of the retainer, resulting in increased vibration and noise.

The band width of the retainer may be 50% or less of the radial dimension between the inner diameter surface of the outer ring and the outer diameter surface of the inner ring. In this case, it is possible to more reliably reduce the amount of grease caught between the pocket and the ball.

The retainer may be made of a resin material with a melting point of 200 to 350°C. In this case, no abnormal sliding marks are observed on the retainer, which is preferable. A resin material having a melting point of less than 200° C. melts or wears abnormally due to frictional heat caused by sliding between the ball and the pocket wall. A resin material having a melting point exceeding 350° C. increases manufacturing costs.

The ball may be a ceramic ball. In this case, for example, by making the specific gravity smaller than that of a steel ball made of bearing steel or the like, it is possible to increase the speed of the rolling bearing and improve the heat resistance.

The rolling bearing may be a rolling bearing for a motor. Rolling bearings for motors can reduce vibration, improve lubrication life, and reduce manufacturing costs. can.

The rolling bearing retainer of the present invention is a retainer used in the above-described rolling bearing of the present invention.

Any combination of at least two configurations disclosed in the claims and/or the specification and/or the drawings is included in the present invention. In particular, any combination of two or more of each claim is included in the invention.

The present invention will be more clearly understood from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and drawings are for illustration and description only and should not be used to define the scope of the invention. The scope of the invention is defined by the appended claims. In the accompanying drawings, the same part number in multiple drawings indicates the same or corresponding part.
1 is a longitudinal sectional view of a rolling bearing according to a first embodiment of the invention; FIG. FIG. 2 is an enlarged cross-sectional view of a main part of the same rolling bearing; FIG. 3 is a front view of the retainer of the rolling bearing as seen from the axial direction; It is an enlarged front view of the main part of the retainer. It is an expanded sectional view of the same retainer. FIG. 4B is a sectional view along line IVB-IVB of FIG. 4A; It is a schematic diagram showing a rolling bearing for a motor in which the same rolling bearing is applied to a motor. and FIG. 11 is an enlarged vertical cross-sectional view of a main part of a conventional rolling bearing. FIG. 3 is a front view of a conventional rolling bearing retainer viewed from the axial direction; FIG. 10 is an enlarged vertical cross-sectional view of a main part of another conventional rolling bearing; FIG. 6 is a front view of another conventional rolling bearing retainer viewed from the axial direction. FIG. 6 is a front view of another conventional rolling bearing retainer viewed from the axial direction.

[First embodiment]
A rolling bearing and a rolling bearing retainer according to an embodiment of the present invention will be described with reference to FIGS. 1 to 5. FIG.
<Regarding rolling bearings>
As shown in FIG. 1, the rolling bearing 1 of this example is a deep groove ball bearing comprising an inner ring 2, an outer ring 3, and a plurality of rolling elements interposed between rolling surfaces 2a, 3a of the inner and outer rings 2, 3. , a retainer 6 for holding each ball 5, and a seal 4. The balls 5 are steel balls or ceramic balls.

An annular space is formed between the outer circumference of the inner ring 2 and the inner circumference of the outer ring 3, and the openings at both ends in the axial direction of this annular space are closed by seals 4,4. Lubricating grease is enclosed in the closed annular space. A seal mounting groove 7 is formed on the inner peripheral surface of the outer ring 3 , and an inner ring seal groove 8 is formed on the outer peripheral surface of the inner ring 2 . As shown in FIG. 2 , each seal 4 in this example is a non-contact seal in which the lip does not contact the inner ring seal groove 8 . The seal 4 is formed by molding a rubber material 4b on a metal core 4a.

<About retainer 6>
As shown in FIG. 3A, the retainer 6 is of a rolling element guide type, and as shown in FIG. 4B, is composed of two synthetic resin annular bodies 10, 10 that overlap each other in the axial direction. In the retainer 6 of FIG. 3A, when the two annular bodies 10, 10 are coupled, the outer diameter surfaces of the annular bodies 10, 10 form cylindrical surfaces having the same diameter except for the notch 13b. Each inner diameter surface of 10, 10 forms a cylindrical surface with the same diameter except for the notch portion 13a. Each annular body 10 is formed by, for example, injection molding a synthetic resin. The two annular bodies 10, 10 have the same shape and can be molded with the same mold.

As the synthetic resin, polyolefin-based resins, thermosetting resins, engineering plastics, and super engineering resins can be used as long as they are injection-moldable and have sufficient heat resistance, oil resistance, mechanical strength, etc. as cage materials. Plastic or the like can be used. Considering heat resistance, the retainer 6 is preferably made of a resin material having a melting point of 200°C to 360°C, preferably 200°C to 350°C. If the melting point is less than 200° C., the resin may be melted or abnormally worn due to frictional heat caused by sliding between the ball and the pocket wall. In order to increase the strength of the resin, 15 to 45% by mass of glass fiber, carbon fiber, aramid fiber, or the like may be added, but resins without these fibers may also be used.

Examples of the thermosetting resin include epoxy resin and phenol resin.
Examples of the engineering plastic include polyacetal resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polycarbonate resin, tetrafluoroethylene-hexafluoroethylene-hexafluoropropylene copolymer resin, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin, Examples include ethylene-tetrafluoroethylene copolymer resins and wholly aromatic polyester resins.
The super engineering plastics include polyether ether ketone resins, polyphenylene sulfide resins, polyetherimide resins, polyamideimide resins, polyethersulfone resins, thermoplastic polyimide resins, and polyamide resins (e.g. PA46, PA66, PA9T, PA10T, etc.). etc. A mixture of two or more of the above resins, a polymer alloy material, and the like can also be used.

As shown in FIGS. 4A and 4B, each annular body 10 has a plurality of semi-cylindrical pocket wall portions 13 and a plurality of coupling plate portions 14 . A plurality of pocket wall portions 13 are arranged at regular intervals in the circumferential direction and constitute the inner wall surface of the pocket 12 each holding the ball 5 . The plurality of connecting plate portions 14 connect the pocket wall portions 13 adjacent to each other in the circumferential direction.

The connecting plate portion 14 has a mating surface 15 that comes into surface contact when the two annular bodies 10, 10 are connected. A connecting claw 16 protruding in the axial direction and a connecting hole 17 into which the connecting claw 16 of the other annular body 10 is inserted are formed near the center in the circumferential direction of the mating surface 15 of the connecting plate portion 14 .
A hook portion 19 is formed at the axial tip of the coupling claw 16 , and the hook portion 19 of one annular body 10 engages with a stepped portion 18 formed on the inner surface of the coupling hole 17 of the other annular body 10 . This engagement prevents the coupling claw 16 from slipping out of the coupling hole 17, and the two annular bodies 10, 10 are overlapped and coupled to each other.

The coupling plate portion 14 has a projecting wall portion 20 and a housing recess portion 21 . The projecting wall portion 20 is provided at one circumferential end of the mating surface 15 of one annular body 10 so as to project in the axial direction. The accommodation recess 21 is provided at the other end in the circumferential direction of the mating surface 15 of one annular body 10 and accommodates the projecting wall portion 20 of the other annular body 10 . Since the coupling plate portion 14 has the projecting wall portion 20 and the accommodation recess 21 described above, the seam between the annular bodies 10, 10 when the two annular bodies 10, 10 are coupled can be positioned from the center of the pocket 12 in the axial direction. It is designed to come to a misaligned position. As a result, when the ball 5 contacts the coupling plate portion 14 due to delay or advance of the ball 5 during operation of the bearing, it is possible to prevent the ball 5 from contacting the position of the seam between the two annular bodies 10, 10. . Therefore, it becomes possible to hold the ball 5 stably.

When the two annular bodies 10, 10 are joined, the protruding wall portion 20 and the accommodating recess 21 are sized to create circumferential and axial gaps 22, 23 between the protruding wall portion 20 and the accommodating recess 21. ing. As a result, it is possible to prevent the projecting wall portion 20 from interfering with the accommodation recess portion 21 due to the difference in shrinkage after the annular body 10 is injection molded. 15 can be brought into close contact with each other.

A partially concave spherical surface 25 along the outer circumference of the ball 5 is formed at both ends of each pocket 12 in the circumferential direction. The partially concave spherical surfaces 25 are formed facing each other in the forward and backward direction of the ball 5 with the ball 5 interposed therebetween. The radius of curvature of the partially concave spherical surface 25 is set slightly larger than the radius of the ball 5 .

<Regarding the notches 13a and 13b>
FIG. 3B is a partially enlarged view of IIIB of FIG. 3A. As shown in FIGS. 3A and 3B, the retainer 6 is configured such that the pocket wall portion 13 has a band width W1, which is the radial dimension of the pocket wall portion 13, smaller than the radial dimension W2 of the coupling plate portion 14. Notch portions 13a and 13b are provided on the inner diameter surface and the outer diameter surface of each. The notch portions 13a and 13b on the inner diameter surface and the outer diameter surface have a curved surface shape that is a concave curve when viewed from the bearing axial direction. These notches 13a and 13b are formed, for example, during injection molding of the annular body 10, but they can also be formed by machining or the like after injection molding.

In each pocket wall portion 13, a deepest portion P1 of the notch portion 13a on the inner diameter surface is provided at a circumferential intermediate portion of the inner diameter surface, and a deepest portion P1 of the notch portion 13a is provided at a circumferential intermediate portion of the outer diameter surface. A deepest portion P2 of the notch portion 13b is provided. In each pocket wall portion 13, the band width W1 at the middle portion in the circumferential direction is the smallest, and the band width W1 gradually increases along the curved shape as it goes from the middle portion in the circumferential direction toward both sides in the circumferential direction. formed.

Further, in each pocket wall portion 13, the radial center Pc of the band width W1 that is the minimum between the deepest portion P1 of the cutout portion 13a on the inner diameter surface and the deepest portion P2 of the cutout portion 13b on the outer diameter surface is , near the pitch circle diameter (PCD) of the ball 5 . The minimum band width W1 is 20% or more and 35% or less of the diameter BD of the ball 5, and the circumferential range L1 of each of the notches 13a and 13b is 50% or more and 100% or less of the diameter BD of the ball 5. there is Furthermore, in this embodiment, as shown in FIG. 2, the minimum band width W1 is 50% or less with respect to the radial dimension D1 between the inner diameter surface of the outer ring 3 and the outer diameter surface of the inner ring 2 .

The pocket wall portion 13 is formed thick by the volume reduction due to the notch portions 13a and 13b. Specifically, a conventional pocket wall portion 33 (Fig. 6) without cutouts is used for a synthetic resin retainer used in a deep groove ball bearing having the same inner diameter, outer diameter, and width dimensions. In contrast, in the retainer of this embodiment, the entire pocket wall portion 13 is thickened in the axial direction of the bearing by the volume reduction. As a result, a decrease in rigidity of the retainer 6 due to the notches 13a and 13b can be suppressed.

<Acoustic test>
An acoustic test was conducted to compare the rolling bearing provided with the retainer according to the present embodiment and the rolling bearing provided with the conventional retainer using a testing machine to be described later.
<Test conditions>
Model number (nominal number) of rolling bearing to be tested: 6312 (inner diameter 60 mm x outer diameter 130 mm x width 31 mm)
Rotation speed: 8000min ^-1
Load: Radial load Fr = 500N, axial load Fa = 785N
Judgment method: Auditory judgment during bearing rotation when a predetermined time has passed after the start of the test

In the tester, for example, a drive shaft is rotatably supported by a housing via two rolling bearings, and a belt or the like is attached to a pulley at one end in the longitudinal direction of the drive shaft and driven by a motor to rotate around the axis. configured as possible. Of the two rolling bearings, the rolling bearing on the pulley side is the rolling bearing to be tested, and the other rolling bearing is the supporting bearing. By driving the motor, the drive shaft and the inner ring of each rolling bearing are rotated, and a belt load is applied to the rolling bearing to be tested with a radial load. The testing machine is equipped with a preload spring or the like for applying a predetermined axial load to the rolling bearing to be tested.

<Acoustic test results>

In Table 1, "○" indicates that no abnormal noise was generated in the retainer by auditory judgment, and "×" indicates that abnormal noise was generated in the cage by auditory judgment.

<High speed test>
A high-speed test was performed on a rolling bearing provided with a plurality of retainers having different melting points among the retainers according to the present embodiment. The testing machine is substantially the same as the testing machine for the acoustic test described above.

<Test conditions>
Model number (nominal number) of rolling bearing to be tested: 6312
Rotation speed: 13500min ^-1
Load: Axial load Fa = 588N
Judgment method: Visual judgment after stopping rotation after a predetermined time has passed

<High-speed test results>

<Effect>
According to the rolling bearing 1 and the rolling bearing retainer 6 described above, the grease adhering to the balls 5 in FIG. , the amount of grease caught between the pocket 12 and the ball 5 is reduced. As a result, shear resistance of the grease between the pocket 12 and the ball 5 is reduced, the behavior of the retainer 6 is stabilized, and the vibration and noise values are reduced.
When the band width W1 of the cutouts 13a and 13b exceeds 35% of the diameter BD of the ball 5, or the circumferential range L1 of the cutouts 13a and 13b is less than 50% of the diameter BD of the ball 5, the grease Scraping is reduced, and more grease is caught between the pocket 12 and the ball 5.例文帳に追加In this case, the behavior of the retainer 6 is not stable, and the effect of suppressing vibration and noise is small.

Since the notch 13b is provided on the outer diameter surface of the pocket wall 13, the stationary space is widened. In this case, the notches 33a are provided only on the inner diameter surface of the pocket wall 33 (Fig. 9), or the pocket walls 33 are not provided with notches (Fig. 7). Quiescent space volume increases. By providing the notch portion 13b on the outer diameter surface of the pocket wall portion 13, the amount of grease retained in the stationary space on the inner diameter side of the outer ring is increased. Therefore, it is possible to improve the lubrication life without providing a circumferential groove-shaped grease pocket or the like on the inner diameter surface of the outer ring 3 . Therefore, the manufacturing cost can be reduced as compared with the conventional structure (FIG. 8) in which the grease pocket 31b is provided on the inner diameter surface of the outer ring.

In the case of only the notch 33a on the inner diameter side (Fig. 9), grease is likely to be caught between the pocket and the ball from the outer diameter side without the notch, making it difficult to stabilize the behavior of the retainer, resulting in large vibration and noise. Become. In addition, the volume of the static space on the outer diameter side of the inner ring increases, and although the amount of grease retained in the static space on the outer diameter side of the inner ring increases, it is difficult to contribute to the lubrication of the rolling parts.
In the case of only the notch 33b on the outer diameter side (Fig. 10), the amount of grease retained on the inner diameter side of the outer ring increases and the lubrication life is improved. is likely to be caught, and the behavior of the retainer is difficult to stabilize, resulting in increased vibration and noise.

When the band width W1 of the retainer 6 is 50% or less of the radial dimension D1 between the inner diameter surface of the outer ring 3 and the outer diameter surface of the inner ring 2, the grease caught between the pocket 12 and the ball 5 can be more reliably reduced.
The retainer 6 may be made of a resin material having a melting point of 200 to 350.degree. In this case, no abnormal sliding marks are observed on the retainer 6, which is preferable. A resin material having a melting point of less than 200° C. is melted or abnormally worn due to frictional heat generated by sliding between the ball 5 and the pocket wall portion 13 . A resin material having a melting point exceeding 350° C. increases manufacturing costs.
When the ball 5 is a ceramic ball, for example, it is possible to increase the speed of the rolling bearing 1 and improve the heat resistance by making the specific gravity smaller than that of a steel ball made of bearing steel or the like.

This rolling bearing is used, for example, as rolling bearings 50, 50 for a motor 51, which is schematically shown in FIG. However, it is also possible to apply this rolling bearing to applications other than motors.
If the rolling bearing is a rolling bearing for motors, and if this rolling bearing for motors can reduce vibration, improve lubrication life, and reduce manufacturing costs, it can be applied to motors for various purposes. Versatility as a rolling bearing can be enhanced.

<Other embodiments>
The pocket wall portion of each annular body is not limited to a semi-cylindrical shape, and may be semi-spherical.
The seal may be a contact seal with a lip contacting the inner ring seal groove.
The seal may be a so-called shield plate made only of steel plates.
It may be an open rolling bearing without seals.
Any rolling bearing can be applied to machine tools, industrial machines, vehicles, and the like.
It is also possible to form each annulus by 3D printing or machining.

<Reference proposal example>
Instead of setting the band width to 35% or less of the ball diameter, the band width of the retainer is set to 50% of the radial dimension between the inner diameter surface of the outer ring and the outer diameter surface of the inner ring. The following may be used. Other than that, the configuration is the same as that of the above-described embodiment. Also in this case, the same effects as those described above are obtained.
The rolling bearing according to this reference proposal is described as follows.

It comprises inner and outer rings, a plurality of balls interposed between the inner and outer rings, and a retainer formed with pockets for holding the respective balls, the retainer having two annular bodies overlapping each other in the axial direction, Each annular body includes a plurality of pocket wall portions arranged at regular intervals in the circumferential direction, each forming an inner wall surface of the pocket, and a plurality of connecting plate portions connecting the pocket wall portions adjacent in the circumferential direction. and a rolling bearing in which the two annular bodies are overlapped and connected to each other at the connecting plate portions,
The retainer has cutout portions on the inner diameter surface and the outer diameter surface of the pocket wall portion so that the band width, which is the radial dimension of the pocket wall portion, is smaller than the radial dimension of the coupling plate portion. provided respectively,
In each pocket wall, the center in the radial direction of the band width between the deepest part of the notch on the inner diameter surface and the deepest part of the notch on the outer diameter surface is near the pitch circle diameter of the ball,
The band width of the retainer is 50% or less of the radial dimension between the inner diameter surface of the outer ring and the outer diameter surface of the inner ring, and the circumferential range of each of the cutouts is the diameter of the ball. 50 to 100% of the rolling bearing.

As described above, the preferred embodiment has been described with reference to the drawings, but various additions, changes, and deletions are possible without departing from the scope of the present invention. Accordingly, such are also included within the scope of this invention.

DESCRIPTION OF SYMBOLS 1... Rolling bearing 2... Inner ring 3... Outer ring 5... Ball 6... Cage 10... Annular body 12... Pocket 13... Pocket wall part 13a, 13b... Notch part 14... Coupling plate part

Claims (6)

1. It comprises inner and outer rings, a plurality of balls interposed between the inner and outer rings, and a retainer formed with pockets for holding the respective balls, the retainer having two annular bodies overlapping each other in the axial direction, Each annular body includes a plurality of pocket wall portions arranged at regular intervals in the circumferential direction, each forming an inner wall surface of the pocket, and a plurality of connecting plate portions connecting the pocket wall portions adjacent in the circumferential direction. and a rolling bearing in which the two annular bodies are overlapped and connected to each other at the connecting plate portions,
   The retainer has cutout portions on the inner diameter surface and the outer diameter surface of the pocket wall portion so that the band width, which is the radial dimension of the pocket wall portion, is smaller than the radial dimension of the coupling plate portion. provided respectively,
   In each pocket wall, the center in the radial direction of the band width between the deepest part of the notch on the inner diameter surface and the deepest part of the notch on the outer diameter surface is near the pitch circle diameter of the ball,
   A rolling bearing, wherein the band width is 35% or less of the diameter of the ball, and the circumferential range of each notch is 50 to 100% of the diameter of the ball.
2. The rolling bearing according to claim 1, wherein the band width of the retainer is 50% or less of the radial dimension between the inner diameter surface of the outer ring and the outer diameter surface of the inner ring.
3. The rolling bearing according to claim 1 or claim 2, wherein the retainer is made of a resin material having a melting point of 200 to 350°C.
4. The rolling bearing according to any one of claims 1 to 3, wherein said balls are ceramic balls.
5. The rolling bearing according to any one of claims 1 to 4, which is a rolling bearing for a motor.
6. It has two annular bodies that overlap each other in the axial direction, and each annular body is arranged at regular intervals in the circumferential direction and each constitutes the inner wall surface of the pocket that holds the ball. a plurality of connecting plate portions connecting the pocket wall portions adjacent to each other in the direction, wherein the two annular bodies are overlapped and connected to each other by the respective connecting plate portions; ,
   Cutout portions are provided on the inner diameter surface and the outer diameter surface of the pocket wall portion so that the band width, which is the radial dimension of the pocket wall portion, is smaller than the radial dimension of the coupling plate portion,
   In each pocket wall, the center in the radial direction of the band width between the deepest part of the notch on the inner diameter surface and the deepest part of the notch on the outer diameter surface is near the pitch circle diameter of the ball,
   A retainer for a rolling bearing, wherein the band width is 35% or less of the diameter of the balls, and the circumferential range of each of the notches is 50 to 100% of the diameter of the balls.

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