JP2010065816A - Retainer and ball bearing provided with retainer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a retainer 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 a bearing, and whose life can be extended, and to provide the ball bearing provided with the retainer. <P>SOLUTION: The radius of an inner diameter of a circumferential section having pockets from a retainer center in a steel plate waveform retainer 5 is set larger than the radius of an inner diameter of a circumferential section between pockets from the retainer center. A sliding member SB composed of composition is formed on a surface section 5aa forming at least a guide surface of balls 4 in the pockets. The composition has fullerene and disulfide of prescribed quantities mixed in synthetic resin. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a cage applied to a ball bearing with a sealing plate used for a rotation support portion of various rotary machine devices and a ball bearing provided with the cage, and in particular, grease sealed inside the bearing for lubrication. The present invention relates to a technology that can prevent the leakage of the grease to the outside by the cage shape and can extend the life of the grease.

  Ball bearings with a sealing plate used in various rotating machinery devices, particularly automobile auxiliary machines, are required to have high temperature durability, high speed durability, muddy water resistance, dust resistance, grease leakage resistance, long life, and low torque. Of these, a contact seal is used to prevent muddy water and dust. For example, the contact seal is attached to the inner peripheral surface of the outer ring, and is provided so that the seal lip is slidably contacted with an inner ring seal groove formed on the outer peripheral surface of the inner ring.

In the ball bearing provided with the contact seal, if the bearing temperature rises in a state where grease is present in the seal lip portion of the contact seal, the following phenomenon occurs. That is, the pressure inside the bearing rises due to the expansion of the air inside the bearing, creating a pressure difference with the outside of the bearing, and the seal lip opens and grease and air leak to the outside of the bearing (hereinafter this phenomenon) (Referred to as “breathing”) (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).

In order to prevent breathing, a notch for ventilation is not provided but the pressure (hereinafter referred to as “tightening force”) for pressing the seal lip against the inner ring seal groove is increased. However, this breathing countermeasure will not only prevent the leakage of grease at the time of a large temperature rise that only causes an increase in torque and causes an internal pressure exceeding the tension.
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 corrugated holder is proposed (patent document 4). 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 5 and 6). However, the former is 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 comes into contact with the inner diameter part of the outer ring. In the former cage, in order to suppress the deformation due to the centrifugal force, it is necessary to use a resin such as a PEEK material having high strength, which is expensive. 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 2007-271078 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. And a ball bearing provided with the cage.

  The cage of the present invention is a ring-shaped cage used for ball bearings and provided with pockets for holding balls at a plurality of locations in the circumferential direction, and the cage center of the inner diameter of the circumferential portion with the pockets In the cage in which the radius from the inside is larger than the radius from the cage center of the inner diameter of the circumferential portion between the pockets, the sliding made of the composition at least on the surface portion of the pocket forming the guide surface of the ball A member is formed, and the composition includes a fullerene and at least one disulfide selected from molybdenum disulfide and tungsten disulfide in a synthetic resin, and the fullerene with respect to the entire composition Is 0.1 volume% or more and 10 volume% or less, and the disulfide is contained by 0.5 volume% or more and 20 volume% or less.

According to this configuration, by making the radius from the cage center of the inner diameter of the circumferential portion with the pocket larger than the radius from the cage center of the inner diameter of the circumferential portion between the pockets, Grease hardly adheres to the inner ring seal groove. This appears particularly when the outer ring rotates. Thereby, leakage of grease can be prevented regardless of whether the seal is a contact type or a non-contact type. Further, since it is not necessary to increase the tightening force of the seal lip, the torque does not increase.
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.

  Therefore, when this cage is made of an iron plate and used in a sealed ball bearing, the high-speed rotation performance peculiar to the so-called iron plate cage while suppressing grease leakage, the bearing internal space larger than the resin cage (hereinafter referred to as the 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.

  The inner surface of the circumferential portion having the pocket may have a curved surface shape that is a concave curve when viewed from the axial direction. It is empirically known that most of the cage damage occurs at the R portion from the circumferential portion between the pockets to the circumferential portion with the pockets. The cage of the present invention has a curved surface shape in which the inner diameter surface of the circumferential portion with pockets is a concave curve without changing the shape of the R portion or the like. Therefore, it is possible to prevent the strength of the entire cage from being lowered, the grease hardly adheres to the shoulder portion of the inner ring and the inner ring seal groove, and the leakage of the grease can be prevented without increasing the torque.

  The inner peripheral surface of the circumferential portion having the pocket may have a polygonal shape having a plurality of corners when viewed from the axial direction. Even in this case, it is possible to prevent a decrease in strength of the entire cage and prevent leakage of grease without increasing torque.

By tilting the inner peripheral surface of the circumferential portion with each pocket so that the circumferential center of each circumferential portion with the pocket has a large diameter, the inner diameter of the circumferential portion with the pocket The radius from the cage center may be larger than the radius from the cage center of the inner diameter of the circumferential portion between the pockets.
With this configuration, while avoiding a decrease in strength of the entire cage, the radius from the cage center of the inner circumferential portion of the pocket is set to the radius from the cage center of the inner radius of the circumferential portion between the pockets. Can be made larger.

Each annular member is composed of two annular members that are axially overlapped with each other, and each annular member is arranged at a predetermined interval in the circumferential direction, and a plurality of hemispherical pocket wall portions that constitute the inner wall surface of the pocket, and adjacent pockets It may consist of a flat plate-like connecting plate portion that connects the wall portions, and both the annular members may be connected to each other at the connecting plate portions.
In this way, when the two annular members are coupled to each other to form one cage, the radius from the cage center of the inner diameter is set to be from the cage center of the inner diameter of the circumferential portion between the pockets. Although the shape is larger than the radius, the cage can be easily processed. Therefore, it is possible to reduce the manufacturing cost of the cage.
According to the ball bearing provided with the cage according to any one of claims 1 to 5, grease leakage from the ball bearing can be suppressed, and high-speed rotation performance peculiar to the iron plate cage can be obtained. . Further, according to this ball bearing, a larger total space volume than that of the ball bearing provided with the resin cage can be secured, and thus the life is extended by an increase in the amount of grease filled in proportion to the total space volume.

  The cage of the present invention is a ring-shaped cage used for ball bearings and provided with pockets for holding balls at a plurality of locations in the circumferential direction, and the cage center of the inner diameter of the circumferential portion with the pockets In the cage in which the radius from the inside is larger than the radius from the cage center of the inner diameter of the circumferential portion between the pockets, the sliding made of the composition at least on the surface portion of the pocket forming the guide surface of the ball A member is formed, and the composition includes a fullerene and at least one disulfide selected from molybdenum disulfide and tungsten disulfide in a synthetic resin, and the fullerene with respect to the entire composition Is 0.1 volume% or more and 10 volume% or less and the disulfide is contained in a volume of 0.5 volume% or more and 20 volume% or less, so that it has excellent high-speed rotation performance and can suppress deformation due to centrifugal force Both aims to reduce the grease leakage, increase the volume of space in the bearing increases Grease quantity, it can be extended bearing life.

An embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a ball bearing incorporating the cage of the present invention, and FIGS. 2 and 3 show the cage. As shown in FIG. 1, this ball bearing 1 is a deep groove ball bearing, and holds an inner ring 2, an outer ring 3, a plurality of balls 4 interposed between the inner and outer rings 2, 3, and each ball 4. A cage 5 and a sealing plate 6 as a contact seal are provided.
An annular space is formed between the outer periphery of the inner ring 2 and the inner periphery of the outer ring 3, and the openings at both axial ends of the annular space are closed by the sealing plate 6. An outer ring seal groove 3 a is formed on the inner peripheral surface of the outer ring 3, and an inner ring seal groove 2 a is formed on the outer peripheral surface of the inner ring 2. The outer end of the sealing plate 6 is attached to the outer ring seal groove 3a, and the inner end of the sealing plate 6 is fitted into the inner ring seal groove 2a so as to slidably contact the inner ring 2. Lubricating grease is enclosed in the closed annular space.

The cage 5 will be described.
As shown in FIGS. 2 and 3, the cage 5 is composed of two annular members 11 manufactured by punching and forming a plate material made of an iron-based metal material, ie, a so-called iron plate. 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.
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 FIG. 2 and FIG. 3, each annular member 11 is arranged at equal intervals in the circumferential direction, and a plurality of hemispherical pocket wall portions 11 a each constituting the inner wall surface of the pocket 5 a and adjacent pocket wall portions. The plate-shaped coupling plate portions 11b that connect the 11a to each other are alternately formed. A rivet hole 11c is formed in the coupling plate portion 11b of the annular member 11 made of iron plate. The two annular members 11 are joined by overlapping the respective coupling plate portions 11b with each other, inserting the rivet 12 into the rivet hole 11c, and crimping both ends of the rivet 12. As described above, when the two annular members 11 are coupled to each other to form one cage 5, the radii from the center of the cage having the inner diameter as described above are different from each other, and the holding is performed. The processing of the vessel 5 is easy.

  As shown in FIG. 2, the cage 5 of this embodiment has a shape in which the inner peripheral surface 5b of the circumferential portion with the pockets 5a is recessed toward the outer diameter side, so there is a concern that the overall strength may be lowered. . However, most of the damage of the conventional standard-shaped cage 25 (Rp = Ri) as shown in FIG. 7 is the R portion from the circumferential portion between the pockets 5a to the circumferential portion with the pockets 5a. It is empirically known to occur at 7. Since the cage 5 of this embodiment does not change the shape of this portion, it can be said that the overall strength does not decrease.

  In order to investigate the state of grease during operation of the ball bearing 1, tests were conducted under the conditions shown in Table 1. The state of adhesion of grease to each part of the bearing after the operation was stopped was as shown in FIG. For comparison, a test was conducted under the same conditions for a bearing incorporating the conventional cage 25 shown in FIG. The state of adhesion of grease to each part of the bearing after the operation was stopped was as shown in FIG.

  According to this test, the grease G adheres to the inner ring seal groove 2a in the case of the bearing incorporating the conventional cage 25, but the grease G does not adhere to the inner ring seal groove 2a in the bearing incorporating the cage 5 of the present invention. I found out. For this reason, it is inferred that in the ball bearing 1 provided with the sealing plate 6, leakage of the grease G from the portion of the inner ring seal groove 2a due to breathing can be prevented.

  Next, a grease leakage frequency confirmation test was performed using a bearing assembled with a contact seal (LU seal manufactured by NTN Corporation). For the test conditions, only the operation time was changed to 15 minutes with respect to the conditions in Table 1. When it was confirmed by visual inspection that grease of an amount of about 30 to 100 mg had jumped out of the bearing, grease leakage was assumed. The test results are shown in Table 2.

  Nine out of 10 grease leaks occurred in the bearing incorporating the conventional cage 25, but none of the bearings incorporating the cage 5 of the present invention produced any grease leakage. This proved that the reasoning was correct.

A sliding member SB made of the composition is formed on at least a surface portion 5aa (FIG. 3) forming the guide surface of the ball 4 in the pocket 5a of the cage 5.
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 2 and Table 3.
(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 are mixed with the solid content of the polyamideimide resin varnish (solvent: N-methyl-2-pyrrolidone) in the proportions shown in Tables 2 and 3 until they are sufficiently uniformly dispersed by a ball mill, and the mixed solution is rubbed Spray method applied to the outer diameter surface of the test SUJ2 ring [outer diameter 40 mm × inner diameter 20 mm × thickness 10 mm (subcurvature R 60), adjusted to a surface roughness Ra 0.7 μm by shot blasting: 17 in FIG. 35] 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. 5 shows a sliding tester. FIG. 5A shows a front view, and FIG. 5B 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
The same test piece as in Example 1 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 is defined as either when the bearing temperature is + 15 ° C (135 ° C) or when the motor load (torque) is 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 5 described above, in the iron plate corrugated cage, the radius of the inner diameter of the circumferential portion with the pocket 5a from the cage center is changed from the cage center of the inner diameter of the circumferential portion between the pockets. By making it larger than the radius, it becomes difficult for grease to adhere to the inner ring shoulder 2b and the inner ring seal groove 2a. This appears particularly when the outer ring rotates. Thereby, leakage of grease can be prevented regardless of whether the seal is a contact type or a non-contact type. Further, since it is not necessary to increase the tightening force of the seal lip, the torque does not increase.
Further, a sliding member SB made of the composition is formed at least on the surface portion 5aa constituting the guide surface of the ball 4 in the pocket 5a, and the composition comprises a predetermined amount of fullerene and disulfide in a synthetic resin. Therefore, the fine particle-shaped fullerene and the disulfide powder are uniformly mixed in the resin body or the film. 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, as shown in FIG. 1, when this cage 5 is used for a sealed ball bearing, the high-speed rotation performance peculiar to the iron plate cage and the total space volume larger than the resin cage are ensured while suppressing grease leakage. As well as an extended grease lubrication life by preventing direct contact between the iron pocket and the steel ball. In addition, it is possible to prevent deformation due to centrifugal force generated during high-speed rotation. Since the amount of grease filled is specified in proportion to the total space volume, an increase in the total space volume leads to an extension of the life due to an increase in the amount of grease filled.
This cage 5 has a curved surface shape in which the inner circumferential surface (inner diameter surface) 5b of the circumferential portion with the pocket 5a is a concave curve when viewed from the axial direction, so that the strength reduction of the cage 5 as a whole is prevented. It is difficult for grease to adhere to the inner ring shoulder 2b and the inner ring seal groove 2a, and leakage of grease can be prevented without increasing torque.

  Next, another embodiment of the present invention will be described. In the following description, portions corresponding to the matters described in the above-described embodiment are denoted by the same reference numerals, and overlapping descriptions 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.

  As shown in FIG. 6, in the retainer 35 according to another embodiment of the present invention, the shape of the inner peripheral surface 5b in the circumferential direction portion with the pocket 5a is a polygonal shape when viewed from the axial direction. Specifically, the inner peripheral surface 5b includes a pair of inclined surface portions 5ba that are inclined toward the outer diameter side with respect to the inner peripheral surface 5c in the circumferential portion between the pockets 5a, and both ends of the inner peripheral surface 5b are outside the pair of inclined surface portions 5ba. It has a trapezoidal shape composed of a constant-diameter surface portion 5bb which is connected to the radial end and has a constant inner diameter. Similarly to the cage 5 of the above embodiment, the cage 35 is also inclined so that the inner circumferential surface 5b of the circumferential portion with the pocket 5a is recessed toward the outer diameter side, and the circle with the pocket 5a. The radius Rp from the cage center of the inner diameter of the circumferential portion is larger than the radius Ri from the cage center of the inner diameter of the circumferential portion between the pockets 5a (Rp> Ri).

As described above, the cage 35 in which the shape of the inner peripheral surface 5b of the circumferential portion with the pocket 5a is polygonal when viewed from the axial direction is also reduced in overall strength, similar to the cage 5 of the embodiment. When it is incorporated in the bearing as shown in FIG. 1, leakage of grease from the inner ring seal groove 2a portion of the bearing 1 can be prevented.
In addition, when making the internal peripheral surface 5b of the circumferential direction part with the pocket 5a into the polygonal shape which has a some corner | angular part, the number of the corner | angular part is not specifically limited. Further, the shape may be asymmetric with respect to a straight line in the radial direction. Furthermore, the inner peripheral surface 5b of the circumferential direction portion with the pocket 5a may be a combination of a flat surface and a curved surface. However, the condition that the radius from the cage center of the inner diameter of the circumferential portion with the pocket 5a is larger than the radius from the cage center of the inner diameter of the circumferential portion between the pockets. In addition, as in the above-described embodiment, the sliding member SB made of the composition is formed at least on the surface portion of the pocket 5a that forms the guide surface of the ball 4, and the composition is made of synthetic resin with fullerene and disulfide. A predetermined amount of product is blended. In this case, the same effects as those of the embodiment shown in FIGS.

It is not limited to the configuration in which the two annular members 11 are joined to form one cage, but a machined cage that is cut out from a steel material into a predetermined shape, and the pocket portion of the machined cage is made of the composition. A sliding member 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 annular member 11 before the two annular members 11 are joined. In this case, since the annular member 11 is washed in a so-called semi-finished product state before the composition is coated on each annular member 11, the cleaning effect can be further enhanced. Therefore, the adhesion of the coating can be further improved.
When the composition is coated on each annular member 11, 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 annular members 11 may be coupled by omitting the rivet 12 that couples the coupling plate portions 11b of the two annular members 11 and providing a claw or the like protruding from a part of the coupling plate portion 11b. In this case, the number of parts can be reduced.
A sealing plate may be provided only at one end of the bearing, and a member other than the bearing may be used at the other end to prevent grease leakage.
In the bearing, ceramic balls may be applied instead of the steel balls.

1 is a cross-sectional view of a ball bearing incorporating a cage according to an embodiment of the present invention. It is a front view of the retainer. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is a figure which shows the test result performed with respect to the ball bearing incorporating the said holder | retainer. FIG. 5A is a front view of the sliding tester, and FIG. 5B is a side view of the sliding tester. It is a front view of the holder | retainer which concerns on other embodiment of this invention. It is a front view of the conventional cage | basket. It is a figure which shows the test result performed with respect to the ball bearing incorporating the said holder | retainer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Ball bearing 2 ... Inner ring 3 ... Outer ring 4 ... Ball 5, 35 ... Cage 5a ... Pocket 5aa ... Surface part 5b ... Inner diameter surface 11 ... Ring member 11a ... Pocket wall part 11b ... Coupling plate part

Claims (6)

A ring-shaped cage that is used for ball bearings and has pockets for holding balls at a plurality of locations in the circumferential direction, and the radius of the inner diameter of the circumferential portion of the pocket from the cage center is determined between the pockets. In the cage in which the inner diameter of the circumferential portion of the cage is larger than the radius from the cage center,
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 is made of synthetic resin fullerene, at least one selected from 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 cage characterized in that it is included.   The cage according to claim 1, wherein the inner circumferential surface of the circumferential portion having the pocket has a curved surface shape that is a concave curve when viewed in the axial direction.   The cage according to claim 1, wherein the inner circumferential surface of the circumferential portion having the pocket has a polygonal shape having a plurality of corners when viewed from the axial direction.   The inner circumferential surface of the circumferential portion with each pocket according to any one of claims 1 to 3, wherein a circumferential central portion of each circumferential portion with the pocket has a large diameter. The cage in which the radius from the cage center of the inner diameter of the circumferential portion between the pockets is larger than the radius from the cage center of the inner diameter of the circumferential portion between the pockets by inclining.   5. The structure according to claim 1, comprising two annular members that are axially overlapped with each other, and each annular member is arranged at a predetermined interval in the circumferential direction, and each constitutes an inner wall surface of the pocket. A plurality of hemispherical pocket wall portions and a flat plate-like connecting plate portion connecting adjacent pocket wall portions, and both annular members are connected to each other at the connecting plate portions. Cage.   A ball bearing comprising the cage according to any one of claims 1 to 5.

Images