JP2010065821A - Retainer for ball bearing and ball bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a retainer for a ball bearing and the ball bearing which is excellent in high speed rotation performance, inhibits deformation due to centrifugal force, reduces grease leak, and has increased grease enclosed capacity due to increased space volume in the bearing, and whose life can be extended. <P>SOLUTION: In an inner diameter side section 46Ai of the retainer 45, a hollow part 50 extending to a retainer outer diameter side from an opening edge at a retainer inner diameter side is provided, and a sliding member composed of composition is formed at least on a surface section forming a guide surface of balls in pockets 46. The composition has fullerene and disulfide of prescribed quantities contained in synthetic resin. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a ball bearing retainer and a ball bearing applied to, for example, a ball bearing with a sealing plate used in a rotation support portion of various rotary machine devices, and in particular, grease sealed inside the ball bearing leaks to the outside. The present invention relates to a technology for preventing the occurrence of grease and extending the life of grease.

Sealed plate bearings used in various rotating machinery devices, particularly automobile auxiliary machines, are required to have high temperature resistance, high speed, mud resistance, dust resistance, grease leakage resistance, long life and low torque. Among these requirements, contact seals are used to prevent muddy water and dust.
By the way, if the bearing temperature rises in a state where grease exists in the seal lip portion, the following phenomenon occurs. In other words, the pressure inside the bearing rises due to the expansion of air inside the bearing, creating a pressure difference from the outside of the bearing, and opening the seal lip to leak grease and air to the outside of the bearing (hereinafter this phenomenon is referred to as “breathing”. Occurs) (Patent Document 1).
In order to prevent this, there is one in which a notch for ventilation is provided in a part of the seal lip (Patent Document 1). However, if only air leaks from this notch while the bearing temperature rises due to operation, grease leakage due to respiration will decrease, but if grease adheres to the notch, the same grease leak will occur (patented) Reference 2).
Even if a breathing measure is taken by increasing the pressure on the inner ring seal groove of the seal lip (hereinafter referred to as “tightening force”) without providing a notch for ventilation, the tightening force only increases torque. When the temperature rises to cause the above internal pressure, grease leakage should not be prevented.
Further, when the bearing temperature is lowered, an adsorption phenomenon of the seal lip tip due to a decrease in pressure inside the bearing due to contraction of air inside the bearing occurs, which causes a further increase in torque (Patent Document 3). ). Therefore, even if various seals are used, it is difficult to prevent grease leakage if grease adheres to the inner ring seal groove.

Then, what changed the shape of the iron plate waveform holder is proposed. This is a structure that scrapes off excess grease adhering to the rolling elements and prevents the grease from adhering to the bearing inner ring shoulder due to the shape provided in the pocket (this cage is referred to as "improved cage"). Called).
However, the standard iron plate corrugated cage and the improved cage (SPCC) have a guide surface that is iron, and when sliding with a steel ball, iron wear powder is generated, grease is deteriorated, and the bearing is There is a risk of short life.

Therefore, measures are taken to use a crown-shaped resin cage (PA66 + GF25%) or a two-fold resin cage (Patent Documents 4 and 5). However, the former may be deformed to the outer ring side by the centrifugal force generated at the time of high speed rotation, and the outer diameter part of the cage may come into contact with the inner diameter part of the outer ring. Moreover, in order to suppress the deformation | transformation by a centrifugal force, you have to use resin which consists of PEEK material etc. with high intensity | strength, and it becomes expensive as a cage material. In the latter case, deformation is suppressed, but the volume of grease cannot be increased because the volume of the cage increases and the spatial volume in the bearing decreases. Furthermore, grease leakage occurs in both the former and the latter.
JP 2000-257640 A JP 2005-308117 A JP 2005-69404 A JP 2006-258174 A JP 2007-40383 A

  The iron plate cage generates iron wear powder, which may shorten the bearing life. The crown-shaped resin cage is deformed by centrifugal force and is inferior in high-speed rotation performance because it contacts the seal and the inner diameter of the outer ring. If a high-strength and high-cost resin made of PEEK material or the like is used, the high-speed rotation performance is improved, but the high-speed rotation performance of the corrugated steel sheet cannot be achieved. Further, in the split resin cage, deformation is suppressed, but the volume of grease is not increased because the volume of the cage increases and the spatial volume in the bearing decreases. Further, in both the crown shape and the split cage, grease easily moves to the seal lip portion, and grease leakage is likely to occur.

  The object of the present invention is excellent in high-speed rotation performance, can suppress deformation due to centrifugal force, reduce grease leakage, increase the volume of grease in the bearing by increasing the space volume in the bearing, and extend the bearing life. It is providing the ball bearing cage and ball bearing which can do.

  The ball bearing retainer according to the first aspect of the present invention has pockets for holding balls of ball bearings at a plurality of locations in the circumferential direction, and the inner surface of each pocket is located on the inner diameter side of the ball arrangement pitch circle. In a ring-shaped ball bearing retainer having a concave curved surface with a diameter that becomes smaller as approaching the cage inner diameter side opening edge, the inner surface of each pocket extends from the cage inner diameter side opening edge to the cage outer diameter side. A sliding member made of the composition is formed at least on the surface portion of the pocket that forms the guide surface of the ball, and the composition is made of synthetic resin fullerene, At least one disulfide selected from molybdenum disulfide and tungsten disulfide, and the fullerene is 0.1% by volume or more and 10% by volume or less with respect to the entire composition, and the two Sulfide Characterized in that it contains .5 volume% to 20 volume% or less.

  In a ball bearing using a cage with a conventional general shape with a spherical inner surface of the pocket, when the ball, which is a rolling element, rolls on the inner ring raceway surface, the grease thickness on the inner ring raceway surface is from the Hertz contact center. The grease thickness on the ball surface and the ball surface is also symmetric from the Hertz contact center to the inner raceway surface width. When the grease adhering to the ball surface enters the cage by the rotation of the ball, the grease is scraped off by the cage. The scraped grease adheres to the cage, but part of the grease also adheres to the inner ring shoulder as the amount of grease increases. When the grease adhering to the shoulder portion of the inner ring increases, the grease adheres so as to ride up near the central portion of the pocket of the rotating cage. As the amount of grease that rides on increases, it comes in contact with the grease on the shoulder of the inner ring, and the grease adheres to the inner ring seal groove. This is the movement of grease in a general steel sheet punching cage. Further, in this general-shaped cage, the grease adhered to the central portion of the cage pocket adheres to the inner surface of the seal. As a result, grease that hardly contributes directly to lubrication remains on the inner surface of the seal. In addition, grease shear occurs between the cage pocket and the seal inner surface, and the bearing torque increases.

On the other hand, in the first invention, the inner surface of each pocket of the cage is provided with a recessed portion extending from the opening edge on the cage inner diameter side toward the cage outer diameter side, so that the grease does not adhere to the inner ring shoulder portion. That is, since a recess is provided at the opening edge on the inner diameter side of the cage, which is the position where the grease adheres most to the ball, scraping of the surface of the ball is reduced, and the amount of grease collected on the inner diameter surface of the cage is reduced. Therefore, it is difficult for grease to adhere to the inner ring seal groove, and grease leakage can be prevented by using either a contact type or non-contact type seal. This particularly appears when the outer ring rotates. Therefore, there is no demerit such as an increase in bearing torque due to adhesion to a seal such as a general steel plate punching cage. Furthermore, since it is not necessary to add an element for preventing grease leakage to the sealing function, a seal design specialized for muddy water resistance, dust resistance, and low torque is possible.
Furthermore, a sliding member made of the composition is formed at least on the surface portion of the pocket that forms the guide surface of the ball, and the composition contains a predetermined amount of fullerene and disulfide in the synthetic resin. Shaped fullerene and disulfide powder are uniformly mixed in the resin body or coating. As a result, due to these synergistic effects, the wear resistance and peel resistance are improved, and at the same time, the friction coefficient is lowered. If the fullerene content is less than 0.1% by volume with respect to the entire composition, sufficient wear resistance cannot be obtained. Conversely, if the fullerene content exceeds 10% by volume with respect to the entire composition, poor dispersion results. Gets worse. Further, the disulfide is blended in an amount of 0.5 to 20% by volume, preferably 0.5 to 15% by volume, based on the entire composition. If it is less than 0.1% by volume, sufficient frictional wear characteristics cannot be obtained, and if it exceeds 20% by volume, the wear resistance deteriorates.

  Therefore, when this cage is made of an iron plate and used for a ball bearing, while suppressing leakage of grease, a high-speed rotation performance peculiar to a so-called iron plate cage, a bearing internal space larger than the resin cage (hereinafter referred to as total space volume) As well as preventing the direct contact between the iron pocket and the steel ball, thereby extending the grease lubrication life. In addition, it is possible to prevent deformation due to centrifugal force generated during high-speed rotation. In general, the amount of grease filled is specified in proportion to the total space volume, and an increase in the total space volume leads to a life extension due to an increase in the amount of grease filled.

When the inner surface of the pocket has a concave spherical shape, and the cross-sectional shape of the inner surface of the concave portion along the circumferential direction of the cage is an arc shape having a smaller radius of curvature than the radius of curvature of the concave spherical surface serving as the inner surface of the pocket The above-described grease scraping becomes even less likely to occur.
The recess is provided at one location extending from the center in the cage circumferential direction at the opening edge of the pocket to one side, and has a width larger than half of the width in the cage circumferential direction of the pocket. The inner surface shape of the portion is a cylindrical surface shape that substantially follows the surface of the virtual cylinder centered on the straight line in the radial direction of the cage, and this recess is formed from the opening edge on the cage inner diameter side of the ball arrangement pitch circle. A shape that extends to the vicinity and gradually becomes shallower and narrower as it approaches the ball arrangement pitch circle from the inner diameter edge of the cage may be used. In this case, since the amount of grease scraping on the surface of the ball can be reduced by one recess, the cage structure can be simplified. Therefore, it is possible to simplify the mold structure for forming the recess and to reduce the amount of grease accumulated on the inner diameter surface of the cage. Even when the recesses are post-processed on the inner surface of each pocket, the number of man-hours can be reduced as compared with the case where a plurality of recesses are formed. Therefore, it is possible to reduce the manufacturing cost.

The recesses are provided at a plurality of locations on both sides of the center in the circumferential direction of the cage at the opening edge of the pocket, and the inner surface shape of each of the recesses is centered on a straight line in the radial direction of the cage. It has a cylindrical surface shape substantially along the surface of the virtual cylinder, and this recess extends from the opening edge on the inner diameter side of the cage to the vicinity of the ball arrangement pitch circle, and approaches the ball arrangement pitch circle from the inner diameter edge of the cage. Accordingly, the shape may gradually become shallower and narrower.
As described above, since a plurality of recesses are provided at positions on both sides of the center in the circumferential direction of the cage, the amount of grease scraping on the surface of the ball can be reduced regardless of the rotation direction of the bearing. .
Moreover, when the said shape is pressed, it becomes convex on the pocket outer surface side. However, even if it becomes convex, it does not approach the inner surface of the seal, and the gap between the cage and the seal is the same as that of the standard cage.
In the cage in which the concave portion is provided at one location extending from the center in the circumferential direction of the cage at the opening edge of the pocket at one location, the gap between the cage and the seal is a cage having a plurality of concave portions. Narrower than.

  The recesses are provided at two locations on both sides of the center in the circumferential direction of the cage at the opening edge of the pocket and extend to the vicinity of the outer diameter edge of the cage, and the inner surface shape of these two recesses is The virtual ring has a shape substantially along the surface of one virtual ring, and the virtual ring has a ring outer diameter that fits in a pocket, a circular cross-sectional shape at an arbitrary circumferential position, and the center of the ring is relative to the cage center axis. It may be tilted. In this case, the inner surface shape of the two recessed portions can be easily and accurately formed using a grindstone or the like having a shape along the surface of the virtual ring.

The cross-sectional shape along the circumferential direction of the cage on the inner surface of the recess may be a polygonal shape.
Two ring-shaped cage halves are stacked facing each other in the axial direction, and each of these cage halves includes a spherical shell plate portion whose inner surface forms half of each of the pockets, and an adjacent pocket. The flat plate part used as the space | interval part may be a shape which is located in a line in the circumferential direction. The spherical shell-shaped plate portion is a portion that becomes a part of the spherical shell, and is a bulging portion having a counter sink shape in which both inner and outer surfaces are spherical. In this case, the spherical shell plate portion and the flat plate portion can be integrally provided by forming the cage half using a press die or the like. Thereafter, the two cage halves can be easily stacked and assembled.

  In this invention, the ball bearing cage of the second invention is formed with a sliding member made of the same composition as the ball bearing cage of the first invention on the surface portion forming the guide surface of the pocket of the cage. The cage is configured as follows. That is, in a ring-shaped ball bearing cage having pockets for holding balls of ball bearings at a plurality of locations in the circumferential direction, two annular half-body cages are stacked facing each other in the axial direction. These cage halves each have a spherical shell-shaped plate portion whose inner surface forms half of each pocket, and a flat plate portion that is a portion between adjacent pockets alternately arranged in the circumferential direction, The plate thickness of the portion located on the outer diameter surface portion of the shoulder height on both sides of the raceway surface of the bearing inner ring in the inner diameter side portion from the ball arrangement pitch circle in the spherical shell-shaped plate portion is greater than the plate thickness of the flat plate portion. Is also thin.

  In the second invention, the retainer is a plate in a portion located at an outer diameter surface portion at a shoulder height on both sides of the raceway surface of the bearing inner ring in the inner diameter side portion of the ball arrangement pitch circle in the spherical shell-shaped plate portion. Since the thickness is made thinner than the plate thickness of the flat plate portion, grease does not adhere to the shoulder portion of the inner ring. Therefore, it is difficult for grease to adhere to the inner ring seal groove, and grease leakage can be prevented by using either a contact type or non-contact type seal. This particularly appears when the outer ring rotates. Therefore, there is no demerit such as an increase in bearing torque caused by adhering to a seal such as a general iron punching cage. Furthermore, since it is not necessary to add an element for preventing grease leakage to the sealing function, a seal design specialized for muddy water resistance, dust resistance, and low torque is possible.

In addition, the strength of the cage is reduced by making the reference plate thickness that is the plate thickness of the outer diameter side portion of the flat plate portion of the cage half and the ball arrangement pitch circle of the spherical shell plate portion equal to the conventional one. Therefore, only grease leakage can be prevented. Furthermore, since the shape of the pocket part which can contact with the ball is the same as the conventional one, the interference force between the cages does not increase due to the increase of the movable range of the cage. Other effects similar to those of the first invention are achieved.
The inner surface of the pocket has a concave spherical shape, and the depth of the concave portion is determined such that the distance from the center of the concave spherical surface of the pocket inner surface to the deepest position of the concave portion is 1.05 times the radius of the ball or more. It's also good.
According to the ball bearing provided with the ball bearing retainer according to any one of claims 1 to 9, since the concave portion opened at the opening edge on the inner diameter side of the retainer is provided, the surface of the ball is scraped off. This reduces grease and makes it difficult for grease to adhere to the inner ring seal groove, thus preventing grease leakage. Therefore, grease does not adhere to the ball bearing seal or the like, and an increase in bearing torque can be suppressed. Further, since the sliding member made of the above-described composition is formed in the cage pocket, the wear resistance and peel resistance are improved and the friction coefficient is lowered at the same time. When this cage is made of an iron plate and used for a ball bearing, it is possible to achieve high-speed rotation performance, securing a large total space volume, and extending the grease lubrication life by preventing direct contact between the iron pocket and the steel ball.

  The ball bearing retainer according to the first aspect of the present invention has pockets for holding balls of ball bearings at a plurality of locations in the circumferential direction, and the inner surface of each pocket is located on the inner diameter side of the ball arrangement pitch circle. In a ring-shaped ball bearing retainer having a concave curved surface with a diameter that becomes smaller as approaching the cage inner diameter side opening edge, the inner surface of each pocket extends from the cage inner diameter side opening edge to the cage outer diameter side. A sliding member made of the composition is formed at least on the surface portion of the pocket that forms the guide surface of the ball, and the composition is made of synthetic resin fullerene, At least one disulfide selected from molybdenum disulfide and tungsten disulfide, and the fullerene is 0.1% by volume or more and 10% by volume or less with respect to the entire composition, and the two Sulfide .5 volume% to 20 volume% is included, so it has excellent high-speed rotation performance, can suppress deformation due to centrifugal force, reduce grease leakage, increase the space volume in the bearing, and add grease Can be increased and the bearing life can be extended.

  In this invention, the ball bearing cage of the second invention is formed with a sliding member made of the same composition as the ball bearing cage of the first invention on the surface portion forming the guide surface of the pocket of the cage. The cage is composed of two annular cage halves facing each other in the axial direction, and each cage half has a spherical shell shape whose inner surface forms half of each pocket. The plate portion and the flat plate portion serving as a portion between adjacent pockets are alternately arranged in the circumferential direction, and at least in the inner diameter side portion of the ball arrangement pitch circle in the spherical shell plate portion, at least of the bearing inner ring Since the plate thickness of the portion located on the outer diameter surface portion of the shoulder height on both sides of the raceway surface is made thinner than the plate thickness of the flat plate portion, it has excellent high-speed rotation performance, can suppress deformation due to centrifugal force, and grease leakage To reduce the volume of the bearing and increase the space volume in the bearing. Increasing the amount of encapsulation, it can be extended bearing life.

  An embodiment of the present invention will be described with reference to FIGS. The ball bearing cage according to this embodiment is applied to, for example, a ball bearing used for a rotation support portion of various rotary machine devices. As shown in FIG. 1, the bearing 1 includes a plurality of balls 4 interposed between the raceway surfaces 2 a and 3 a of the inner ring 2 and the outer ring 3, and a cage 45 that holds these balls 4 is provided on both side surfaces. Non-contact type seal members 6 and 6 for sealing the bearing space are provided. In this case, the bearing is a deep groove ball bearing with a seal. The ball 4 is made of, for example, a steel ball.

  Each seal member 6 is composed of an annular cored bar 7 and a rubber-like member 8 fixed integrally to the cored bar 7, and this seal member 9 is formed in a seal mounting groove 9 formed on the inner peripheral surface of the outer ring 3. The outer peripheral part of the member 6 is fixed to a fitting state. The inner ring 2 has a seal groove 10 formed of a circumferential groove at a position corresponding to the inner peripheral portion of each contact seal, and a seal lip 6 a formed at the inner peripheral side end of the contact seal is formed in the seal groove 10 of the inner ring 2. Make sliding contact.

The cage 45 will be described.
As shown in FIGS. 2 to 4, the retainer 45 is composed of, for example, two retainer halves 47 manufactured by punching and forming a plate material made of an iron-based metal material by pressing. The material of the cage is not particularly limited to iron-based metal materials, and copper-based metal materials, aluminum-based metal materials, and the like can be used.
A sliding member SB made of a composition to be described later is formed on at least a surface portion 5aa (FIG. 4) forming the guide surface of the ball 4 in the pocket 46 of the cage 45.

Examples of the ferrous metal material include case hardening steel (SCM), cold rolled steel (SPCC), hot rolled steel (SPHC), carbon steel (S25C to S55C), stainless steel (SUS304 to SUS316), mild steel (SS400). ) Etc. can be used.
As the copper-based metal material, a copper-zinc alloy (HBsC1, HBsBE1, BSP1-3), a copper-aluminum-iron alloy (AlBC1), etc., and as the aluminum-based metal material, an aluminum-silicon alloy (ADC12) or the like is used. it can.

  As shown in FIGS. 3 and 4, the retainer 45 is a ring-shaped one having pockets 46 for holding the balls 4 at a plurality of locations in the circumferential direction and the inner surface of each pocket 46 having a concave spherical shape. is there. This retainer 45 is formed by joining two annular retainer halves 47 shown in a perspective view in FIG. 5 so as to face each other in the axial direction and joining them together by a rivet 49 inserted through a rivet hole 48. Composed. Each of these cage halves 47 has a plurality of spherical shell-shaped plate portions 46A having a partial spherical shell shape whose inner surface forms half of the pocket 46, and a flat plate portion 47a serving as a portion between adjacent pockets 46; The spherical shell plate portions 46A are alternately arranged in the circumferential direction. The spherical shell-shaped plate portion 46A is a part that becomes a part of the spherical shell, in other words, a countersink-shaped bulging portion in which both the inner and outer surfaces are spherical. The projected shape of the cage half 47 in the axial direction is a ring shape having a constant radial width over the entire circumference.

  A part of the cage half 47 is enlarged and shown in a perspective view in FIG. FIG. 6 is a diagram in the case where the pocket inner surface is a monotonous spherical surface in a portion corresponding to FIG. In FIG. 6, a portion A indicated by a two-dot chain line indicates a circumferential band in which the flat plate portions 47a of the cage half 47 are arranged in the circumferential direction. The spherical shell plate portion 46A, which is a half of the pocket 46, is formed at a portion of the circumferential band A that is not the flat plate portion 47a. One side portion of the spherical shell-shaped plate portion 46A in the drawing is an inner diameter side portion 46Ai of the cage 45, and the other side portion of the spherical shell-shaped plate portion 46A is an outer diameter side portion 46Ao of the cage 45.

As shown in FIG. 7, the inner surface of the pocket 46 (spherical shell plate portion 46 </ b> A) of the retainer 45 of this embodiment is formed on the inner diameter side portion 46 </ b> Ai of the retainer 45 from the opening edge on the retainer inner diameter side. A recess 50 extending on the outer diameter side is provided, and a cross-sectional shape of the inner surface of the recess 50 along the circumferential direction of the cage (that is, a cross-sectional shape taken along a plane perpendicular to the cage central axis) is defined as the inner surface of the pocket 46. An arc shape having a radius of curvature Rb smaller than the radius of curvature Ra of the concave spherical surface.
The recessed portion 50 is provided at one location so as to extend from the center OW 46 in the cage circumferential direction at the opening edge of the pocket 46 to one side, and the width W 50 of the recessed portion 50 is the width W 46 in the cage circumferential direction of the pocket 46. The width is almost the whole. The width W50 of the recess 50 is preferably larger than half of the width W46 of the pocket 46, more preferably 2/3 or more, or more preferably 3/4 or more.
The inner surface shape of the recessed portion 50 is a cylindrical surface shape that substantially follows the surface of the virtual cylinder V centered on the straight line L in the radial direction of the cage 45 as shown in FIG. The virtual cylinder V may be the surface of a grindstone that processes the recess 50. The recessed portion 50 extends from the opening edge on the inner diameter side of the cage to the ball arrangement pitch circle PCD in the radial direction of the cage, and gradually decreases, that is, gradually, from the inner diameter edge of the cage to the ball arrangement pitch circle PCD. The shape is shallow and narrow. In this embodiment, the recess 50 extends to the ball arrangement pitch circle PCD. However, the depression 50 may extend slightly to the outer diameter side of the cage from the ball arrangement pitch circle PCD, or may slightly extend to the ball arrangement pitch circle PCD. You may not reach it. The ball arrangement pitch circle PCD is also called a pocket PCD.

  The depth of the recess 50 is such that the distance Rc from the center O46 of the concave spherical surface of the pocket inner surface to the deepest position of the recess 50 is 1.05 times or more the radius of the ball 4 (just 1.05 times). Preferably). The radius of curvature Ra of the concave spherical surface serving as the inner surface of the pocket 46 is slightly larger than the radius of the ball 4 and is less than 1.05 of the radius of the ball 4.

FIG. 8 shows another example of the shape of the inner surface of the pocket 46 (spherical shell plate portion 46A) of the retainer 45. As shown in FIG. In this example, two recessed portions 50A provided in the inner diameter side portion 46Ai of the inner surface of the pocket 46 (spherical shell-shaped plate portion 46A) are located on both sides of the center OW 46 in the cage circumferential direction at the opening edge of the pocket 46. As you are. The inner surface shape of each recess 50A is such that the cross-sectional shape along the circumferential direction of the cage (that is, the cross-sectional shape taken along a plane perpendicular to the cage central axis) is larger than the radius of curvature Ra of the concave spherical surface serving as the inner surface of the pocket 46. It has an arc shape with a small radius of curvature RAb. Specifically, as shown in FIG. 5B, it has a cylindrical surface shape substantially along the surface of each virtual cylinder VA centered on the radial line LA of the cage 45. is there. The recessed portion 50A extends from the opening edge on the cage inner diameter side to the vicinity of the ball arrangement pitch circle PCD in the radial direction of the cage, and gradually decreases from the cage inner diameter edge toward the ball arrangement pitch circle PCD. The shape gradually becomes shallower and narrower.
The positions of the two recessed portions 50A are, for example, two symmetrical places where the circumferential orientation angle with respect to the center OW46 in the circumferential direction of the cage at the opening edge of the pocket 46 is 40 ° ± 15 °. Also in this example, the depth of the recess 50A is such that the distance RAc from the center O46 of the concave spherical surface of the pocket inner surface to the deepest position of the recess 50A is 1.05 times or more the radius of the ball 4. Is preferable (it may be just 1.05 times).
In this embodiment, the number of the recessed portions 50A is two, but may be three or more.

  FIG. 9 shows still another example of the shape of the inner surface of the pocket 46 (spherical shell plate portion 46A) of the retainer 45. As shown in FIG. In this embodiment, in the embodiment of FIG. 8, the cross-sectional shape of the recess 50C (50A) (the cross-sectional shape along the circumferential direction of the cage) is a polygonal shape instead of an arc shape. Specifically, as shown in FIG. 5B, a polygonal shape substantially along the surface of each polygonal column (regular decagonal column in the illustrated example) VC centering on the radial line LA of the cage 45. It is. The recessed portion 50C extends from the opening edge on the inner diameter side of the cage to the vicinity of the ball arrangement pitch circle PCD in the radial direction of the cage, and gradually decreases from the inner diameter edge of the cage to the ball arrangement pitch circle PCD. The shape gradually becomes shallower and narrower. The other configuration in this embodiment is the same as the example of FIG.

  FIG. 10 shows still another example of the shape of the inner surface of the pocket 46 (spherical shell plate portion 46A) of the retainer 45. As shown in FIG. In this example, the recessed portions 50B provided in the inner diameter side portion 46Ai of the inner surface of the pocket 46 (spherical shell-shaped plate portion 46A) are positioned on both sides of the center OW46 in the cage circumferential direction at the opening edge of the pocket 46. Although it is the same as that of embodiment of FIG. 8 by being provided in the location, each recessed part 50B is extended to the cage | basket outer-diameter edge vicinity. The cross-sectional shape along the circumferential direction of the cage of the inner surface of the recessed portion 50B is an arc shape having a radius of curvature RBb smaller than the radius of curvature Ra of the concave spherical surface serving as the inner surface of the pocket 46, and details are shown in FIG. As shown, the shape is substantially along the surface of one virtual ring VB. The virtual ring VB may be an outer peripheral surface of a grindstone that processes the recess 50B. The virtual ring VB has a ring outer diameter that fits in the pocket 46, and has a donut shape with a circular cross-sectional shape at an arbitrary circumferential position, and the ring center OVB is placed on the cage center axis O as shown in FIG. It has an inclination to it.

In addition, in this invention, the cross-sectional shape along the cage | basket circumferential direction of dent part 50A-50C is not restricted to the shape of each example of FIGS. 8-10, Partial elliptical shape, rectangular groove shape, trapezoidal groove shape, Any other cross-sectional shape may be used. In addition, the cross-sectional shape of the recesses 50A to 50C may be asymmetric with respect to the center of the recess.
The inner surface shape of the pocket 46 is not limited to a spherical shape, and may be any shape as long as the inner diameter side portion of the pocket arrangement pitch circle PCD becomes a smaller diameter as it approaches the cage inner diameter side opening edge, for example, the ball arrangement pitch circle PCD. Further, the outer diameter side portion may be a cylindrical surface shape, and the inner diameter side portion may be a conical surface shape.

FIG. 12 shows a method for manufacturing the cage 45. This manufacturing method is a method for manufacturing an iron plate punching cage, in which a steel plate is first pressed and a ring-shaped metal strip 51 is punched out. Next, as shown in FIG. 12A, a convex press die 52 for molding the inner surface of the spherical shell plate portion 46A of the cage half 47 and the outer surface of the spherical shell plate portion 46A are molded. A press die set 54 composed of the concave side press die 53 is prepared, and the ring-shaped metal strip 51 is sandwiched between the convex side press die 52 and the concave side press die 53, and FIG. The cage half 47 is press-molded as in B). This press molding may be performed in two stages of rough pressing and finishing pressing, or may be performed once.
Although only one convex side press die 52 and one concave side press die 53 are shown in the drawing, each of the convex side press die 52 and the concave side press die 53 is a cage half 47. The same number of spherical shell plate portions 46A are arranged in the circumferential direction and provided as a single mold, and a plurality of spherical shell plate portions 46A are formed simultaneously.
The two cage halves 47 thus obtained are overlapped as shown in FIG. 12C, and the portion where the flat plate portion 47a of the cage half 47 is overlapped with a rivet 49 as shown in FIG. The cage 45 is joined.

  In FIG. 13, the convex side press die 52 and the concave side press die 53 used for the finish pressing step in press molding are shown for molding the cage half 47 of FIG. On the hemispherical convex surface of the convex side press mold 52, a concave portion molding die portion 52a for molding the inner surface of the concave portion 50A in the pocket 46 (spherical shell plate portion 46A) is partially formed. Further, the concave side press mold 53 is partially formed with a concave portion back surface molding die 53a for molding the outer surface of the concave portion 50A in the pocket 46 (spherical shell plate portion 46A). Although a convex part will be formed in the outer surface side of a holder | retainer pocket, if it is non-contact with a seal | sticker, there is no functional problem. In this case, the convex press mold 52 and the concave press mold 53 are also provided as a single mold corresponding to the number of spherical shell plate portions 46A of the cage half 47, and a plurality of spherical shell shapes are provided. The plate portion 46A is formed at the same time.

When the cage half 47 of FIG. 8 is formed, the inner surface of the spherical shell-like plate portion 46A has a shape having a recessed portion 50A in a part of a simple hemispherical concave surface. If the concave portion 50A is further press-molded into a part of the hemispherical concave surface after forming the concave shape, the manufacturing process is increased by one step as compared with the case of forming the conventional iron plate punching cage. .
In this embodiment, as described above, for forming a recess portion, the inner surface of the recess portion 50A in the pocket 46 (spherical shell plate portion 46A) is formed on the hemispherical convex surface of the convex press die 52 used in the finishing pressing step. Since the mold part 52a is partially formed, the recessed part 50A can be formed at the same time in the finishing pushing process, and the cage 45 can be efficiently manufactured without increasing the manufacturing process.

Further, the shape and surface roughness of the hemispherical convex surface of the convex pressing mold 52 used in the finishing pressing step are transferred to the inner surface of the cage pocket 46, and the pocket inner surface is inserted into the ball 4 ( In order to come into contact with FIG. 2), it is necessary to reduce the surface roughness of the pocket inner surface. Since the inner surface of the pocket is a simple concave spherical surface in the conventional iron plate punching cage, the surface roughness is reduced by polishing the hemispherical convex surface of the convex press die with a concave grinding stone or the like. However, in the case of this embodiment, as described above, the hemispherical convex surface of the convex-side press mold 52 is a part of a simple hemispherical convex surface, and a concave portion molding die portion 52a corresponding to the concave portion 50A of the pocket inner surface. The surface roughness cannot be reduced by polishing with a concave-shaped grindstone or the like as in the conventional example.
Thus, in this embodiment, the convex convex spherical surface of the convex press mold 52 used in the finishing pressing step is surface-finished by shot blasting, polishing with an electron beam, or lapping by jetting an abrasive. In this case, lapping is generated by obtaining abrasive material having elasticity and adhesiveness by adding moisture to the abrasive grains and sliding the abrasive material on the surface of a mold as a workpiece at high speed. A method of surface finishing by frictional force is preferred. As such wrapping, aero wrapping (Yamashi Towers Co., Ltd.) sold as a mold ultra-mirror finishing device can be employed. In this way, the convex convex spherical surface of the convex press mold 52 is surface-finished by shot blasting, electron beam, or lapping by jetting an abrasive, so that there is no need for manual polishing, and there is no unevenness and low cost. The surface roughness of the convex convex spherical surface of the side press mold 52 can be reduced.

14 to 16 show test results of confirming the grease adhesion state. In this test, a ball bearing incorporating the retainer 45 of this embodiment (the embodiment of FIG. 7 and the embodiment of FIG. 8) and a ball bearing incorporating a general iron plate punching retainer are shown in the following table. A comparison was made by driving under the condition of 1.
FIG. 14 and FIG. 15 show the grease adhesion state of the ball bearing using the retainer 45 of this embodiment (the embodiment of FIG. 7 and the embodiment of FIG. 8 respectively), and FIG. The grease adhesion state of the ball bearing using

  From the test results of FIGS. 14 to 16, in the ball bearing (FIG. 16) in which a general steel plate punching cage is incorporated, grease adheres to the inner ring seal groove, but the ball bearing in which the cage 45 of this embodiment is incorporated. (Examples of FIGS. 14 and 15) show that there is no adhesion of grease.

  Further, a contact seal (NTN LU seal) was assembled to each of the ball bearings, and a grease leakage frequency confirmation test was also conducted. In this test, the operation time was changed to 15 minutes for the test conditions shown in Table 1. The test results are shown in Table 2 below. The grease leakage in this case is defined as that about 30 to 100 mg of grease that can be visually confirmed jumps out of the bearing.

  According to Table 2, grease leakage occurred in 9 out of 10 sealed ball bearings incorporating the conventional cage, but out of 4 sealed ball bearings incorporating the cage of this embodiment. It can be seen that there are no grease leaks.

  As can be seen from these test results, in the ball bearing retainer 45 of this embodiment, the shape of the pocket 46 is different from that of the conventional example as described above, so that the grease adheres to the shoulder of the inner ring. Can be eliminated. In other words, since a recess is provided at the opening edge on the inner diameter side of the cage, where the grease adheres most to the ball, scraping of the surface of the ball when grease scraping occurs reduces the inner diameter of the cage. The amount of grease that accumulates on the surface is reduced. Therefore, grease does not adhere to the inner ring seal groove, and no grease leakage occurs regardless of whether a contact type or non-contact type seal is used. This effect is characteristic especially when the outer ring rotates. Therefore, there is no problem caused by the grease adhering to the seal unlike a general iron plate punched cage. Furthermore, since it is not necessary to add an element for preventing grease leakage to the sealing function, a seal design specialized for muddy water resistance, dust resistance, and low torque is possible. Moreover, since the ball bearing cage of this embodiment can be pressed, a high-strength one can be manufactured at a low cost, and the distance from the seal does not change as compared with a general steel plate punched cage.

The sliding member SB will be described.
As shown in FIGS. 3 and 4, a sliding member SB made of the composition is formed on at least a surface portion 5aa (FIG. 4) forming the guide surface of the ball 4 in the pocket 46 of the cage 45 of the present invention. Yes.
The synthetic resin that can be used in the composition is not particularly limited as long as it is a material that has oil resistance, has high film strength when formed into a film, and has excellent wear resistance. Examples of such resins include epoxy resins, phenol resins, polycarbodiimide resins, furan resins, bismaleimide triazine resins, unsaturated polyester resins, silicone resins, polyamino bismaleimide resins, aromatic polyimide resins and other thermosetting resins, polyolefins Resin, polyacetal resin, polyamide resin, polyphenylene ether resin, polyphenylene sulfide resin, polysulfone resin, polyether sulfone resin, polyetherimide resin, thermoplastic polyimide resin, aromatic polyamideimide resin, polybenzimidazole resin, polyetherketone resin And thermoplastic resins such as polyether nitrile resin, fluororesin, and aromatic polyester resin. Among these, preferred are aromatic polyamideimide resin, aromatic polyimide resin, epochine resin, phenol resin, polyphenylene sulfide resin and the like. These synthetic resins can be blended with various fillers in the form of fibers and particles as necessary.

In the present invention, a particularly preferable synthetic resin is a polyimide resin excellent in film forming ability. Examples of the polyimide resin include a polyimide resin having an imide bond in the molecule and a polyamideimide resin having an imide bond and an amide bond in the molecule.
Among the polyimide resins, an aromatic polyimide resin is preferable. The aromatic polyimide resin is a resin having a repeating unit represented by Chemical Formula 1, and a polyamic acid that is a precursor of a resin having a repeating unit represented by Chemical Formula 1 is also used. it can. R ₁ is the residue of an aromatic tetracarboxylic acid or derivative thereof, and R ₂ is the residue of an aromatic diamine or derivative thereof. Examples of such R ₁ or R ₂ include a phenyl group, a naphthyl group, a diphenyl group, and an aromatic group in which these are connected by a connecting group such as a methylene group, an ether group, a carbonyl group, or a sulfone group.

  Examples of aromatic tetracarboxylic acids or derivatives thereof include pyromellitic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetra Carboxylic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 1,2,5,6-naphthalene tetracarboxylic dianhydride, bis (2,3-dicarboxyphenyl) Examples thereof include methanoic dianhydride, and these are used alone or in combination.

Examples of aromatic diamines or derivatives thereof include 4,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl sulfone, 4,4′-diaminodiphenylmethane, metaphenylenediamine, paraphenylenediamine, and 4,4′-bis. Examples include diamines such as (3-aminophenoxy) biphenyl ether or diisocyanates.
Examples of the aromatic polyimide resin obtained by a combination of the aromatic tetracarboxylic acid or derivative thereof and the aromatic diamine or derivative thereof include those having a repeating unit shown in Table 3. These are resins having no heteroatoms in R ₁ and R ₂ .

In the aromatic polyimide resin in Table 3, polyimides C and D having a high ratio of aromatic rings in the molecule are preferable, and polyimide D is particularly suitable for the present invention. As a commercial item of aromatic polyimide resin varnish, U varnish by Ube Industries, Ltd. is mentioned, for example.

The polyamide-imide resin that can be used in the present invention is a resin having an amide bond and an imide bond in the polymer main chain, and can be obtained by reacting a polycarboxylic acid or a derivative thereof with a diamine or a derivative thereof.
Examples of polycarboxylic acids include dicarboxylic acids, tricarboxylic acids, and tetracarboxylic acids. Polyamideimide resins include (1) combinations of dicarboxylic acids and tricarboxylic acids and diamines, and (2) dicarboxylic acids and tetracarboxylic acids and diamines. (3) a combination of tricarboxylic acid and diamine, and (4) a combination of tricarboxylic acid or tetracarboxylic acid and diamine. Each of the polycarboxylic acid and the diamine may be a derivative. Examples of polycarboxylic acid derivatives include acid anhydrides and acid chlorides, and examples of diamine derivatives include diisocyanates. Diisocyanate may be used that has been stabilized with a blocking agent necessary to prevent the isocyanate group from changing over time. Examples of the blocking agent include alcohol, phenol and oxime.
Moreover, an aromatic and an aliphatic compound can be used for polycarboxylic acid and diamine, respectively. The polyamideimide resin that can be used in the present invention is preferably excellent in elongation, and it is preferable to use an aliphatic compound in combination with an aromatic compound.
Further, it can be modified with an epoxy compound.

Examples of tricarboxylic acid or derivatives thereof include trimellitic anhydride, 2,2 ′, 3-biphenyltricarboxylic anhydride, 3,3 ′, 4-biphenyltricarboxylic anhydride, 3,3 ′, 4-benzophenone Examples include tricarboxylic acid anhydride, 1,2,5-naphthalene tricarboxylic acid anhydride, 2,3-dicarboxyphenylmethylbenzoic acid anhydride, and these are used alone or in combination.
Trimellitic anhydride is preferred because it is mass-produced and is easy to use industrially.

  Examples of tetracarboxylic acid or derivatives thereof include pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic acid Dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 2,3,5,6-pyridinetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride 3,4,9,10-perylenetetracarboxylic dianhydride, 4,4'-sulfonyldiphthalic dianhydride, m-terphenyl-3,3 ', 4,4'-tetracarboxylic acid Dianhydride, 4,4'-oxydiphthalic dianhydride, 1,1,1,3,3,3-hexafluoro-2,2-bis (2,3- or 3,4-dicarboxyphenyl) propane Dianhydride, 2,2-bis (2,3- or , 4-Dicarboxyphenyl) propane dianhydride, 2,2-bis [4- (2,3- or 3,4-dicarboxyphenoxy) phenyl] propane dianhydride, 1,1,1,3,3 , 3-Hexafluoro-2,2-bis [4- (2,3- or 3,4-dicarboxyphenoxy) phenyl] propane dianhydride, 1,3-bis (3,4-dicarboxyphenyl)- 1,1,3,3-tetramethyldisiloxane dianhydride, butanetetracarboxylic dianhydride, bicyclo- [2,2,2] -oct-7-ene-2: 3: 5: 6-tetracarboxylic An acid dianhydride etc. are mentioned.

  Examples of dicarboxylic acids or derivatives thereof include succinic acid, glutaric acid, adipic acid, azelaic acid, suberic acid, sebacic acid, decanedioic acid, dodecanedioic acid, dimer acid, isophthalic acid, terephthalic acid, phthalic acid, naphthalenedicarboxylic acid , Oxydibenzoic acid, aliphatic dicarboxylic acid having carboxyl groups at both ends of a polybutadiene oligomer (Nisso-PB, C series manufactured by Nippon Soda Co., Ltd., Hycar-RLP, CT series manufactured by Ube Industries, Ltd., manufactured by Thiokol Co., Ltd. HC-polymer series, General Tire's Telagen series, Phillips Petroleum's Butaretz series, etc.), carbonate diols (trade names PLACEL, CD-205, 205PL, manufactured by Daicel Chemical Industries, Ltd.) 5HL, 210,210PL, 210HL, 220,220PL, hydroxyl equivalent or more carboxyl equivalent become dicarboxylic acid ester dicarboxylic acid obtained by reaction of 220HL) can be mentioned.

  Examples of diamines or derivatives thereof include 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4 '-[2,2-bis (4- Phenoxyphenyl) propane] diisocyanate, biphenyl-4,4′-diisocyanate, biphenyl-3,3′-diisocyanate, biphenyl-3,4′-diisocyanate, 3,3′-dimethylbiphenyl-4,4′-diisocyanate, 2, 2,2'-dimethylbiphenyl-4,4'-diisocyanate, 3,3'-diethylbiphenyl-4,4'-diisocyanate, 2,2'-diethylbiphenyl-4,4'-diisocyanate, 3,3'-dimethoxy Biphenyl-4,4'-diisocyanate 2,2′-dimethoxybiphenyl-4,4′-diisocyanate, naphthalene-1,5-diisocyanate, naphthalene-2,6-diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, isophorone diisocyanate 4,4'-dicyclohexylmethane diisocyanate, transcyclohexane-1,4-diisocyanate, hydrogenated m-xylylene diisocyanate, lysine diisocyanate, carbonate diols (trade names PLACEL, CD-205, 205PL manufactured by Daicel Chemical Industries, Ltd.) , 205HL, 210, 210PL, 210HL, 220, 220PL, 220HL), obtained by reacting diisocyanate having an isocyanate equivalent of a hydroxyl equivalent or higher Diisocyanate such as diisocyanate.

  Examples of diamines include siloxane diamines (silicone oil X-22-161AS (amine equivalent 450), X-22-161A (amine equivalent 840), X-22-161B (amine) having amino groups bonded to both ends of dimethylsiloxane. Equivalent 1500), X-22-9409 (amine equivalent 700), X-22-1660B-3 (amine equivalent 2200) (above, manufactured by Shin-Etsu Chemical Co., Ltd., trade name), BY16-853 (amine equivalent 650), BY16 -853B (amine equivalent 2200) (above, manufactured by Toray Dow Corning Silicone Co., Ltd., trade name)), both-terminal aminated oligomers such as both-terminal aminated polyethylene and both-terminal aminated polypropylene, both-terminal aminated polymer, oxyalkylene Diamines with groups (Jeffamine D series, Jeffamine ED series, Jeffamine XTJ-511, Jeffamine XTJ-512, both of San Techno Chemical Co., trade name), and the like.

  Unlike an aromatic polyimide resin, a polyamide-imide resin having a repeating unit of an amide bond and an imide bond in a resin solution state without passing through a precursor is particularly preferred in the present invention. Further, diisocyanate-modified, BPDA-modified, sulfone-modified and rubber-modified resins of polyamideimide resin can be used. Examples of commercially available polyamideimide resin varnishes include HPC5020 and HPC7200 manufactured by Hitachi Chemical Co., Ltd.

  In the present invention, the polyamideimide resin is preferably a polyamideimide resin having an elongation percentage of the resin film of 60% to 120%. If the elongation is less than 60%, the adhesiveness to the base material is poor and peeling easily occurs, and peeling or elution of the metal base material easily occurs in an environment in contact with a lubricating oil containing a sulfur-based additive. If the elongation exceeds 120%, the heat resistance is lowered and the oil tends to swell. As a commercial item of the polyamide-imide resin whose elongation rate of a resin film is 60%-120%, Hitachi Chemical Co., Ltd. make and brand name HPC7200-30 are mentioned, for example.

In the present invention, the elongation percentage of the polyamideimide resin film is measured by the following method.
The polyamide-imide resin solution is applied onto a glass substrate that has been degreased with acetone and then cleaned with nitrogen gas blow, pre-dried at 80 ° C for 30 minutes and then at 150 ° C for 10 minutes, and finally the molecular structure of the polyamide-imide resin is obtained. Dry for 30 minutes at a suitable curing temperature. The cured coating film is peeled off from the glass substrate to obtain a resin film with a thickness of 80 ± 8 μm. This film is made into a 10 mm × 60 mm strip test piece, the distance between chucks is 20 mm, the tensile speed is 5 mm / Elongation (%) is measured with a tensile tester at room temperature in minutes.

Fullerene blended in the polyimide resin is a carbon molecule composed of a carbon 5-membered ring and a 6-membered ring and having various polyhedral structures closed in a spherical shape. As a third carbon allotrope following graphite and diamond, H. W. Kroto and R.K. E. It is a new carbon material discovered by Smalley et al. As a typical molecular structure, a C _{60 having} a so-called soccer ball-like structure in which ₆₀ carbon atoms constitute a spherical truncated icosahedron composed of 12 five-membered rings and 20 six-membered rings. Similarly, there are C ₇₀ composed of ₇₀ carbon atoms, and higher fullerenes having a larger number of carbon atoms such as C ₇₆ , C ₇₈ , C ₈₂ , C ₈₄ , C ₉₀ , C ₉₄ , C _96, etc. . Of these, C ₆₀ and C ₇₀ are typical fullerenes. Moreover, a multimer is obtained by making these react. In the present invention, any fullerene can be used, either spherical or multimeric.

  The fullerene production method includes a laser evaporation method, a resistance heating method, an arc discharge method, a thermal decomposition method, etc., and specifically disclosed in, for example, Japanese Patent No. 2802324, which is under reduced pressure or inactive. Fullerenes are obtained by gas existence, generation of carbon vapor, cooling and cluster growth.

On the other hand, in recent years, a combustion method has been put to practical use as an economical and efficient mass production method. As an example of the combustion method, an apparatus in which a burner is installed in a decompression chamber is used, and a hydrocarbon raw material and oxygen are mixed and supplied to the burner while ventilating the inside of the system with a vacuum pump to generate a flame. Then, the soot-like substance produced | generated by the said flame is collect | recovered with the collection | recovery apparatus provided downstream. In this production method, fullerene is obtained as a solvent-soluble component in soot and is isolated by solvent extraction, sublimation or the like. The obtained fullerene is usually a mixture of C ₆₀ , C ₇₀ and higher order fullerene, and can be further purified to isolate C ₆₀ , C _{70 and the} like.
The fullerene used in the present invention is not particularly limited in its structure and production method, but those having a carbon number of C ₆₀ or C ₇₀ or a mixture thereof are particularly preferred.

Fullerene can be used as a solid compounding agent or as a compounding agent obtained by dissolving and dispersing fullerene in an organic solvent. In any case, C ₆₀ , C _{70 and} higher order fullerenes can be used alone or in a mixed state, but these are used in a mixed state from the viewpoint of dispersibility in the resin and the like. It is preferable.
In order to further improve dispersibility, the average particle size at the time of mixing is 100 μm or less, preferably 50 μm or less, more preferably 10 μm or less.

  The blending ratio of fullerene to the composition for the sliding member SB is 0.1 to 10% by volume, preferably 0.1 to 5% by volume of solid fullerene based on the whole composition. If the amount is less than 0.1% by volume, sufficient wear resistance cannot be obtained. If the amount exceeds 10% by volume, the dispersion becomes poor and the wear resistance deteriorates.

  Powdered molybdenum disulfide and tungsten disulfide can be used. From the viewpoint of dispersibility and surface smoothness of the coating, the particle size is 10 μm or less, preferably 5 μm or less. The mixing ratio of molybdenum disulfide and tungsten disulfide to the composition for the sliding member SB is 0.5 to 20% by volume, preferably 0.5 to 15% by volume, based on the entire composition. If it is less than 0.1% by volume, sufficient frictional wear characteristics cannot be obtained, and if it exceeds 20% by volume, the wear resistance deteriorates.

The composition for the sliding member SB of the present invention has a solid lubrication such as polytetrafluoroethylene and graphite for the purpose of stabilizing the friction coefficient and improving the initial conformability without reducing the wear resistance. The agent can be used in combination with fullerene and molybdenum disulfide or tungsten disulfide.
As a preferred embodiment of the composition for the sliding member SB of the present invention, a resin composition in which fullerene and at least one disulfide selected from molybdenum disulfide and tungsten disulfide are dispersed and blended in a polyimide resin. It is a thing.

  The case where the composition for the sliding member SB of the present invention is applied to a rolling bearing having a metal coating that hardly dissolves in an environment in contact with a lubricating oil containing a sulfur component or a sulfur atmosphere will be described. As a result of intensive studies on this rolling bearing, the polyimide resin coating excellent in adhesion and heat resistance does not swell or dissolve even when immersed in a lubricating oil containing a sulfur component. It was found that metal elution into the lubricating oil hardly occurs by forming a polyimide resin film on the surface even with a low metal. For this reason, a cage in which a polyimide resin coating is formed on the surface portion forming the guide surface of the ball is manufactured, and by attaching this cage, a coating that does not easily elute in an environment that comes into contact with a lubricating oil containing a sulfur component. It became possible to obtain a rolling bearing having

A method for coating the composition on the guide surface of the cage pocket will be described.
First, a cage as a base formed of an iron-based metal material is sufficiently washed to remove surface contamination. Examples of the cleaning method include immersion cleaning with an organic solvent, ultrasonic cleaning, steam cleaning, acid / alkali cleaning, and the like.
For the purpose of improving the adhesion of the coating, it is possible to perform shot blasting (including shot peening, WPC, etc.), chemical etching, and phosphate coating treatment as pretreatment. The surface roughness of the substrate can be set in a range of Ra = 0.3 or more, and preferably Ra = 0.5 to 1.0. When Ra is less than 0.3, a sufficient anchor effect cannot be obtained and the adhesion cannot be improved. On the other hand, when the surface roughness of the substrate is large, the finished surface becomes rough. However, if the surface roughness is adjusted to be small by machining such as polishing, it can be used as a cage. Moreover, if Ra = 0.5 to 1.0, it is possible to obtain a small surface roughness without performing sufficient adhesion and machining.

Next, a coating film of the composition for the sliding member is formed on the surface of the cage by spray coating, dip coating, electrostatic coating, tumbler coating, electrodeposition coating, or the like. A preferred coating thickness is 1-100 μm, more preferably 1-50 μm. Further, in the process of forming the film, the excessively adhered varnish can be removed by physical and chemical methods such as wiping, centrifuging and air blowing, and adjusted to a desired thickness.
After the coating is formed, solvent removal, drying, melting, cross-linking, and the like are performed by heat treatment to complete the cage having the coating formed on the guide surface and the like. When the film thickness is increased, it may be overcoated. It is also possible to perform machining or tumbling after the coating is completed.

The materials used in the examples and comparative examples of the present invention are collectively shown as follows. [] Is an abbreviation shown in Table 4 and Table 5.
(1) Polyamideimide resin varnish [PAI]
Hitachi Chemical Co., Ltd. HPC-5020, Elongation: 70%
(2) Aromatic polyimide resin varnish [PI]
U varnish-A made by Ube Industries
(3) Mixed fullerene [mixed fullerene]
Frontier Carbon's mixed fullerene, C ₆₀ (diameter: 0.71 nm) is about 60 wt%, C ₇₀ (major axis diameter: 0.796 nm, minor axis diameter: 0.712 nm) is about 25 wt% with the balance being higher order fullerene It is a mixture.
(4) Molybdenum disulfide powder [MoS ₂ -0.5 μm]
Nippon Molybdenum M5, average particle size 0.5 μm
(5) Tungsten disulfide powder [WS ₂ -1 μm]
WS2A manufactured by Nippon Lubricant Co., average particle size 1 μm
(6) Polytetrafluoroethylene powder [PTFE-0.3 μm]
KD-1000AS dispersion (solvent: NMP) manufactured by Kitamura Co., Ltd., average particle size 0.3 μm
(7) Graphite powder [graphite-6 μm]
Lonza KS-6, average particle size 6 μm

Example 1, Examples 3-7, Comparative Examples 3-10
Various fillers were mixed with the solid content of the polyamideimide resin varnish (solvent: N-methyl-2-pyrrolidone) at the ratios shown in Tables 4 and 5 until they were sufficiently uniformly dispersed by a ball mill, and the mixed liquid was rubbed Apply the spray method to the outer diameter surface of the test SUJ2 ring [outer diameter 40 mm × inner diameter 20 mm × thickness 10 mm (sub-curvature R 60), adjusted to surface roughness Ra 0.7 μm by shot blasting: 17 in FIG. 17] And coated. Moreover, the surface of a SPCC square bar (3 mm × 3 mm × 20 mm) was coated by a dipping method for a lubricating oil immersion test. After coating, it was dried at 100 ° C. for 1 hour, further at 150 ° C. for 1 hour, and baked at 250 ° C. for 1 hour. The number of sprays was adjusted so that the film thickness was 20-30 μm. The coating liquid containing fullerene was prepared in advance as a concentrated liquid in which fullerene was dissolved at a 5% concentration in a mixed solvent of toluene and N-methyl-2-pyrrolidone (mixing weight ratio 50:50). The imide resin varnish was prepared by adding to a predetermined concentration. In addition, the mixture ratio of each component of Table 4 and Table 5 is a ratio in solid content, and all are volume%.

A sliding test was performed using the obtained ring-shaped test piece. FIG. 17 is a diagram showing a sliding tester. FIG. 17A shows a front view, and FIG. 17B shows a side view.
The ring-shaped test piece 17 is attached to the rotating shaft 18, and the steel plate 20 is fixed to the air slider 21 of the arm portion 19. The ring-shaped test piece 17 is rotationally brought into contact with the steel plate 20 while applying a predetermined load 22 from the upper side of the drawing, and the lubricating oil is supplied to the outer diameter surface of the ring-shaped test piece 17 from the felt pad 24 impregnated with the lubricating oil. The The frictional force generated when the ring-shaped test piece 17 is rotated is detected by the load cell 23. Further, after a predetermined time, the state of the polyamide-imide resin coating film formed on the outer diameter surface of the ring-shaped test piece 17 is visually: ○: no significant wear and no peeling, Δ: no significant wear, but there is peeling , X: Indicated in three stages of large wear.
The steel plate 20 used was an SCM415 carburized and tempered product (Hv 700, surface roughness Ra 0.01 μm), and the lubricating oil used was Mobile Velocity Oil No. 3 (VG2, manufactured by ExxonMobil Corp.). The load is 50 N, the sliding speed is 5.0 m / sec, and the test time is 30 minutes. The coefficient of friction was expressed as an average value for 10 minutes before the end of the test. The results are shown in Tables 4 and 5.

  Moreover, the lubricating oil immersion test was done using the obtained SPCC square bar. Three 150 ° C. lubricating oil (poly-α-olefin: Lucant HL-10 (manufactured by Mitsui Chemicals) to which 1% by weight of ZnDTP (LUBRIZOL677A, LUBRIZOL) was added) 2.2 g After 200 hours of immersion, the concentration of the coating components eluted in the lubricating oil was measured. The concentration was quantified by fluorescent X-ray measurement [fluorescent X-ray measurement apparatus: Rigaku ZSX100e (manufactured by Rigaku Corporation)]. The results are shown in Tables 4 and 5.

Example 2
The same method as in Example 1 except that aromatic polyimide resin varnish (solvent: N-methyl-2-pyrrolidone) is used and fullerene is blended in the proportions shown in Table 1 and the firing temperature after coating is 350 ° C. A test piece was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 4.

Comparative Example 2
In the same manner as in Example 1, the test piece was subjected to copper plating (plating thickness: 25 μm) by electroplating. The obtained test piece was evaluated in the same manner as in Example 1. The results are shown in Table 5.

  As is apparent from the results shown in Table 5, in Comparative Example 1 and Comparative Example 2, which are conventionally used metal platings, metal components are eluted in the lubricating oil in the lubricating oil immersion test. In particular, the result was a large amount of copper elution during copper plating. In Comparative Example 3 in which a resin film containing no additive was formed, the friction coefficient was small, but peeling occurred during the friction test. Although the comparative example 4 which mix | blended only fullerene did not peel in a friction test, the friction coefficient increased compared with the resin single-piece | unit. In Comparative Example 5 in which polytetrafluoroethylene was blended in addition to fullerene, the friction coefficient was lowered, but peeling occurred. In Comparative Example 6 in which graphite was blended, wear was great. Since Comparative Example 7 has a small amount of fullerene, the peel resistance is not improved. In Comparative Examples 8 and 9, since the blending amount of fullerene or molybdenum disulfide was larger than a predetermined amount, the dispersion was poor, and the amount of wear was increased because the resin content as a binder was small and could not hold the additive. Further, Comparative Example 10 containing only molybdenum disulfide had almost the same characteristics as the resin alone (Comparative Example 3).

  On the other hand, Examples 1 to 7 shown in Table 4 are polyimide resin films in which a predetermined amount of fullerene and molybdenum disulfide or tungsten disulfide is blended. Therefore, the friction coefficient is low, and peeling during the friction test is remarkable. There was no wear. In the lubricating oil immersion test, no elution of the coating component into the lubricating oil was observed.

表６において、試験軸受である「６２０４ＺＺＣ３」のうち、「６２０４」は軸受サイズ、「ＺＺ」は両密閉板、「Ｃ３」はラジアルすきまＣ３と同義である。Ｆrはラジアル荷重、Ｆaはアキシアル荷重と同義である。同表の被膜「有り」の保持器形式は、鉄板波形保持器であり、この被膜は、鉄板波形保持器の少なくともポケットの案内面に形成している。また、被膜「無し」の保持器形式は、鉄板波形保持器である。 The effect of extending the life of the bearing by applying the resin coating is shown below.
Table 6 shows the operating conditions.

In Table 6, among “6204ZZC3” which is a test bearing, “6204” is a bearing size, “ZZ” is a double sealing plate, and “C3” is synonymous with a radial clearance C3. Fr is synonymous with radial load, and Fa is synonymous with axial load. The retainer type “coated” in the table is an iron plate corrugated retainer, and this film is formed on at least the pocket guide surface of the iron corrugated retainer. Moreover, the retainer type of the film “none” is an iron plate corrugated retainer.

表７において、
軸受温度が+15℃（135℃）となった場合、あるいはモータ負荷（トルク）が2倍となった場合のいずれかで寿命とした。 Table 7 shows the test results tested under the operating conditions in Table 6 above.

In Table 7,
The service life was determined either when the bearing temperature reached + 15 ° C (135 ° C) or when the motor load (torque) doubled.

  From Table 7 above, the bearing provided with the iron plate corrugated cage without a coating had a short life of about 30% compared to the iron plate corrugated cage with a coating. If the sliding between the cage guide surface and the steel ball is not “Iron” vs. “Iron” but “Resin” vs. “Iron”, iron wear powder will not be generated and the bearing life will be long. In Table 7, the conventional iron plate corrugated cage provided with a coating, that is, a PAI film, had a short life of about 28% compared to the coated iron plate corrugated cage. That is, a higher effect can be obtained by providing the coating on the invention cage provided with the recess 50 or the like. In this test, the PAI film was not tested, but there is no problem as long as the PAI film has high sliding resistance and high peel resistance. Therefore, it is understood that it is only necessary to prevent contact between irons on the sliding surface of the cage. For the resin coating on the pocket, a PAI film is suitable in terms of wear resistance and peel resistance.

  According to the cage 45 described above, the sliding member SB made of the composition is formed on the surface portion 5aa which forms at least the guide surface of the ball 4 in the pocket 46, and the composition is composed of fullerene and synthetic resin. Since a predetermined amount of disulfide is blended, fine particle-shaped fullerene and disulfide powder are blended uniformly in the resin body or coating. As a result, due to these synergistic effects, the wear resistance and peel resistance are improved, and at the same time, the friction coefficient is lowered.

  Therefore, when this cage is made of an iron plate and used for a ball bearing, while suppressing leakage of grease, the high-speed rotation performance peculiar to the so-called iron plate cage, ensuring a larger total volume than the resin cage, and iron pockets Extending grease lubrication life by preventing direct contact between steel balls can be achieved. In addition, it is possible to prevent deformation due to centrifugal force generated during high-speed rotation. In general, the amount of grease filled is specified in proportion to the total space volume, and an increase in the total space volume leads to a life extension due to an increase in the amount of grease filled.

Next, another embodiment of the present invention will be described.
In the following description, the same reference numerals are given to portions corresponding to the matters described in the preceding forms in each embodiment, and overlapping description may be omitted. When only a part of the configuration is described, the other parts of the configuration are the same as those described in the preceding section. Not only the combination of the parts specifically described in each embodiment, but also the embodiments can be partially combined as long as the combination does not hinder.

The structure is not limited to a structure in which two retainer halves 47 are combined to form one retainer, and is a machined cage that is cut out from a steel material into a predetermined shape. A sliding member made of a material may be formed. In this case, the rigidity of the cage itself can be increased and deformation due to centrifugal force can be more reliably suppressed.
In the present embodiment, the composition is coated on the entire cage, but is not limited to this form. It is sufficient to coat the composition on at least the guide surface of the pocket.
In the method of coating the composition on the guide surface of the pocket, the composition may be coated in units of each cage half 47 before joining the two cage halves 47 together. In this case, since the cage half 47 is washed in a so-called semi-finished product state before coating the composition on each cage half 47, the cleaning effect can be further enhanced. Therefore, the adhesion of the coating can be further improved.
When the composition is coated on each cage half 47, shot blasting can be easily and reliably performed as a pretreatment with the guide surface of the pocket exposed to the outside. In this case, the workability can be improved and the adhesion of the coating can be further improved.
The two retainer halves 47 may be coupled by omitting the rivet 49 that joins the flat plate portions 47a of the two retainer halves 47 and providing a claw or the like protruding from a part of the flat plate portion 47a. In this case, the number of parts can be reduced.
In the bearing, ceramic balls may be applied instead of the steel balls.

18 to 20 show a ball bearing and its cage according to still another embodiment of the present invention. In this ball bearing, the sliding member SB made of the same composition as described above is formed on the surface portion forming the guide surface of the pocket of the cage 45A, and the cage has the following configuration.
That is, as shown in FIGS. 18 and 19, the ball bearing retainer 45 </ b> A has a range that overlaps the outer diameter surface portion 2 </ b> D that is the shoulder height on both sides of the raceway surface 2 a of the inner ring 2 in the axial direction.
In the ball bearing retainer 45A of this embodiment, in the above configuration, a thin portion 46Aa is formed on the inner diameter side portion of the ball arrangement pitch circle PCD which is the ball arrangement pitch in the spherical shell plate portion 46A. The thin portion 46Aa is obtained by making the plate thickness t1 of the portion located on the outer diameter surface portion 2D, which is the shoulder height on both sides of the raceway surface 2a of the inner ring 2, smaller than the plate thickness t0 of the flat plate portion 47a. The outer diameter surface portion 2D serving as the shoulder height is an outer diameter surface portion continuing at the height of the shoulder portion of the raceway surface 2a of the inner ring 2, and when the seal groove 10 is provided, the raceway surface 2a and the seal groove are provided. It is an outer diameter surface portion between 10 and 10. The spherical shell plate portion 46A reduces the thickness t1 of the portion located in the axial range W of the outer diameter surface portion 2D. In addition, in FIG. 18, the cross-sectional shape in case the spherical shell-shaped board part 46A is not thinned is shown with the imaginary line.

  The plate material t1 may be thinned by thinning the entire range from the portion corresponding to the ball arrangement pitch circle PCD to the inner diameter side in the radial direction of the cage, and between the ball arrangement pitch circle PCD and the cage inner edge. The range from the midway point to the inner diameter edge may be made thinner. In these cases, the plate thickness t1 may gradually become thinner toward the inner diameter side in the radial direction of the cage so that the inner diameter edge becomes the minimum plate thickness. You may do it. Furthermore, while maintaining the shape of the inner surface of the pocket of the spherical shell-shaped plate portion 46A, even if the plate thickness is reduced so that the shape of the outer surface changes, the shape of the outer surface of the spherical shell-shaped plate portion 46A is maintained. The plate thickness may be reduced so that the shape on the inner surface side of the pocket changes.

  Further, in this embodiment, as shown in FIG. 19, in the arc-shaped range along the inner diameter edge of the spherical shell-shaped plate portion 46A, both ends are left and the whole is thinned. Depending on the relationship between the outer diameter surface portion 2D and the width of the retainer 45A, as shown in FIG. 21, the thin portion 46Aa having a reduced plate thickness is on both sides excluding the center of the arc of the inner diameter edge of the spherical shell plate portion 46A. It may be divided into two places.

  The retainer 45A is formed with a thin portion 46Aa on the inner diameter portion of the spherical shell plate portion 46A constituting the pocket 46 in this way, and this thin portion 46Aa is the outer diameter surface portion of the shoulder portion of the inner ring 2. It is a portion that overlaps with 2D in the axial direction, and is a portion where the grease adhering to the surface of the ball 4 is scraped by the cage 45A, or the portion where the scraped grease moves. If the plate thickness t1 of this portion 46Aa is thin, the amount of grease that can be deposited here decreases, so the frequency and amount that can reach the outer diameter surface portion 2D of the inner ring 2 decreases, and as a result, the grease flows to the outside of the bearing. Leakage can be prevented. That is, the grease easily moves to the outer diameter side of the cage 45A, and the amount of grease that can remain on the inner diameter side is reduced.

However, reducing the overall plate thickness of the cage reduces the strength of the cage alone, so that the cage may be damaged when repeated stress is applied to the cage under misalignment or external vibration. It is difficult to occur.
Therefore, in the inner diameter portion of the retainer 45A, the plate thickness is reduced only in the range W that overlaps the outer diameter surface portion 2D serving as the shoulder portion of the inner ring 2 in the axial direction, thereby substantially increasing the strength of the retainer 45A. There is a ball bearing retainer 45A that is not lowered and can prevent grease leakage.

  In order to reduce the plate thickness t1, only the inner diameter side of the flat plate initially punched into the ring may be thinned and press molded. Further, in a press mold when a cage is formed by pressing from an annular flat plate having a uniform thickness, the clearance distribution between a pair of molds is reduced so that only the thickness of the region shown in FIGS. 19 and 21 decreases. It may be changed.

1 is a partially broken perspective view of a bearing provided with a ball bearing retainer according to an embodiment of the present invention. It is sectional drawing which fractured | ruptured the bearing partially. It is a perspective view of the cage for ball bearings. It is sectional drawing of the principal part of the cage for ball bearings. It is a perspective view of the cage half of the same ball bearing cage. It is a partial expansion perspective view which simplifies and shows a pocket shape about a part of the cage half. (A) is a partial enlarged perspective view highlighting an example of the inner surface of the spherical shell plate portion in the cage half, and (B) is a perspective view showing a state in which a virtual cylinder is added to the perspective view. (A) A partial enlarged perspective view highlighting another example of the inner surface of the spherical shell plate portion in the cage half, (B) is a perspective view showing a state in which a virtual cylinder is added to the perspective view. . (A) The partial expansion perspective view which emphasizes and shows another example of the inner surface of the spherical shell-shaped board part in the cage half, (B) is a perspective view showing a state in which a virtual polygonal column is added to the perspective view It is. (A) A partial enlarged perspective view highlighting still another example of the inner surface of the spherical shell plate portion in the cage half, (B) is a perspective view showing a state in which a virtual cylinder is added to the perspective view. is there. It is explanatory drawing which shows the relationship between the spherical shell-shaped board part and a virtual ring in a cross section. It is explanatory drawing which shows the manufacturing process of the cage for ball bearings of this embodiment. It is a perspective view of the press die set used for the manufacturing process. It is explanatory drawing of the result of the grease leak test of the ball bearing incorporating the cage | basket of the structure shown in FIG. It is explanatory drawing of the result of the grease leak test of the ball bearing incorporating the cage | basket of the structure shown in FIG. It is explanatory drawing of the result of the grease leak test of the ball bearing incorporating the general iron plate punching cage. It is a figure which shows a sliding test machine. It is sectional drawing which fractured | ruptured partially the bearing provided with the cage for ball bearings concerning other embodiment of this invention. It is a partial expansion perspective view which shows the spherical shell-shaped board part in the holder | retainer half body of the holder | retainer integrated in the same bearing. It is a top view which shows the assembly which integrated the cage for ball bearings of the embodiment in the inner ring. It is a partial expansion perspective view which shows the modification of the spherical shell-shaped board part in the cage half body of the same cage.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Bearing 2 ... Inner ring 2D ... Outer surface part 3 ... Outer ring 4 ... Ball 5aa ... Surface part 45 ... Retainer 46 ... Pocket 46A ... Spherical shell-like plate part 47 ... Retainer half body 47a ... Flat plate part 50, 50A, 50B , 50C ... Recessed portion PCD ... Ball arrangement pitch circle SB ... Sliding member

Claims (10)

There are pockets that hold the balls of the ball bearings at multiple locations in the circumferential direction, and the inner surface of each pocket is a recess that becomes smaller in diameter as the portion closer to the inner diameter side of the ball arrangement pitch circle approaches the opening edge on the inner diameter side of the cage. In a ring-shaped ball bearing cage with a curved surface,
Provided on the inner surface of each pocket is a recess extending from the opening edge on the inner diameter side of the cage to the outer diameter side of the cage,
A sliding member made of the composition is formed at least on the surface portion of the pocket that forms the guide surface of the ball, and the composition is made of synthetic resin fullerene, molybdenum disulfide, and tungsten disulfide. At least one disulfide selected from the group consisting of 0.1% by volume to 10% by volume of the fullerene and 0.5% by volume of the disulfide with respect to the entire composition. The ball bearing retainer is characterized by being contained in an amount of not less than 20% and not more than 20% by volume.   2. The circle according to claim 1, wherein the inner surface of the pocket has a concave spherical shape, and the cross-sectional shape of the inner surface of the concave portion along the circumferential direction of the cage is smaller than the radius of curvature of the concave spherical surface serving as the inner surface of the pocket. Ball bearing cage that is arcuate.   In Claim 1 or Claim 2, the said recessed part spreads in the both sides from the center of the holder circumferential direction in the opening edge of the said pocket, and is provided in one place, From the half of the width | variety of the pocket holder circumferential direction The inner surface shape of the recess is a cylindrical surface shape substantially along the surface of the virtual cylinder centering on the radial straight line of the cage, and the recess is formed on the inner diameter side of the cage. The ball bearing retainer has a shape that extends from the opening edge to the vicinity of the ball arrangement pitch circle and gradually becomes shallower and narrower as it approaches the ball arrangement pitch circle from the inner diameter edge of the cage.   In Claim 1 or Claim 2, the said dent part is located in the both sides of the center of the cage circumferential direction in the opening edge of the pocket, and is provided in a plurality of places, and the inner surface shape of each dent part is It has a cylindrical surface shape that substantially follows the surface of each virtual cylinder centered on a straight line in the radial direction, and this recess extends from the opening edge on the inner diameter side of the cage to the vicinity of the ball arrangement pitch circle. A ball bearing retainer having a shape that gradually becomes shallower and narrower as it approaches the ball arrangement pitch circle from the inner diameter edge.   In Claim 1 or Claim 2, the said recessed part is provided in two places located in the both sides of the center of the cage circumferential direction in the opening edge of the pocket, and extends to the vicinity of the outer diameter edge of the cage. The inner surface shape of the two recessed portions is a shape substantially along the surface of one virtual ring, the virtual ring is a ring outer diameter that fits in a pocket, and a cross-sectional shape at an arbitrary circumferential position is circular, Ball bearing cage with ring center inclined relative to cage center axis.   The ball bearing retainer according to claim 1, wherein a cross-sectional shape along the circumferential direction of the retainer on the inner surface of the recess is a polygonal shape.   In any one of Claims 1 thru | or 6, two cage | baskets of the cyclic | annular body are piled up facing each other in the axial direction, and each of these cage halves has an inner surface of each pocket. A ball bearing retainer having a shape in which a spherical shell-shaped plate portion forming a half and a flat plate portion serving as a portion between adjacent pockets are alternately arranged in the circumferential direction. In a ring-shaped ball bearing cage having pockets for holding balls of ball bearings at a plurality of locations in the circumferential direction,
Two ring-shaped cage halves are stacked facing each other in the axial direction, and each of these cage halves includes a spherical shell plate portion whose inner surface forms half of each of the pockets, and an adjacent pocket. The flat plate portions that are the intermediate portions are alternately arranged in the circumferential direction, and at least the shoulder heights on both sides of the raceway surface of the bearing inner ring in the inner diameter side portion of the ball arrangement pitch circle in the spherical shell plate portion The plate thickness of the portion located on the outer diameter surface portion is made thinner than the plate thickness of the flat plate portion,
A sliding member made of a composition is formed on at least a surface portion of the pocket forming the guide surface of the ball, and the composition comprises at least one selected from synthetic resin fullerene, molybdenum disulfide and tungsten disulfide. Two disulfides, and the fullerene is 0.1% by volume or more and 10% by volume or less and the disulfide is 0.5% by volume or more and 20% by volume or less based on the entire composition. A ball bearing retainer characterized by being included.   9. The inner surface of the pocket according to claim 1, wherein the inner surface of the pocket has a concave spherical shape, and the depth of the concave portion is determined from the center of the concave spherical surface of the pocket inner surface to the deepest position of the concave portion. However, the ball bearing retainer has a depth that is 1.05 times or more the ball radius.   A ball bearing comprising the ball bearing cage according to any one of claims 1 to 9.

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