JP4732992B2 - Rolling bearing - Google Patents

Description

  The present invention relates to a high-temperature rolling bearing, and more particularly, to a rolling bearing in which fluorine-based high-temperature lubricating grease is used that is preferably used in a fixing portion of an electrical accessory such as an automobile or an electrophotographic apparatus used at a high temperature. Further, the present invention relates to a rolling bearing that has a relatively small amount of grease, such as in a vacuum, and is used under boundary lubrication conditions.

  The rolling bearing is filled with lubricating grease in order to impart lubricity. This lubricating grease is obtained by kneading base oil and thickener as main components, and synthetic oil such as mineral oil, ester oil, silicone oil, ether oil as base oil, and lithium soap as thickener. Metal soaps and urea compounds are generally used. In addition, various additives such as an antioxidant, a rust inhibitor, a metal deactivator, and a viscosity index improver are blended in the lubricating grease as necessary.

In recent years, along with demands for miniaturization, weight reduction, and quietness of automobiles, miniaturization, weight reduction, quietness improvement, and sealing in engine rooms have been attempted. High performance and high efficiency are required for the performance of the system. Since the life of the lubricating grease enclosed in the rolling bearing is usually shorter than the service life due to fatigue of the bearing itself, the life of the bearing itself depends on the life of the lubricating grease. For this reason, the lubricating grease used in these electrical accessories must withstand higher temperatures than urea-based lubricating grease.
Conventional grease used in rolling bearings used for fan clutches with temperatures as high as around 200 ° C is heat resistant using fluororesin powder as a thickener and perfluoropolyether (hereinafter referred to as PFPE) oil as the base oil. Fluorine-based lubricating grease with excellent properties is used.

In general, a roller bearing for a roll is frequently used in a fixing unit of a copying machine or a printer (printer) using an electrophotographic apparatus in order to rotatably support a fixing roller. This fixing unit is a part that is fixed to paper by pressurizing toner adhering to the paper at a high temperature of about 250 ° C., and the roll support rolling bearing of the fixing unit is used at a high temperature. Many. In particular, in order to heat the heat roll from the inside of the hollow shaft and to heat from the inside, the bearing may be used at a temperature exceeding 200 ° C. In addition, heat roll-supported rolling bearings are sometimes used via resin heat insulating sleeves to lower the temperature of the bearings, but the temperature of the bearing end faces can still be close to 200 ° C due to radiant heat. Conventionally, as a grease for a rolling bearing used under such a high temperature condition, a fluorine-based grease that is less deteriorated at a high temperature and has a long life is used.
In general, when the lubricant is exposed to vacuum, the base oil evaporates because the vapor pressure of the base oil is high. For this reason, the degree of vacuum does not increase, or measurement equipment provided in the vacuum chamber or the vacuum equipment is contaminated to cause a problem. As a countermeasure, fluorine-based grease has been often used to lubricate rolling bearings used in vacuum.

  These fluorine-based greases exhibit good lubricity when a sufficient amount is present, but when supply to the rolling contact part or sliding part is insufficient and boundary lubrication occurs, the base oil PFPE oil and Steel (iron), which is a bearing material, reacts with the base oil, causing wear of the steel and shortening its life. This reaction is particularly remarkable at the sliding portion between the cage and the rolling element, and the surface of the rolling element is corroded and wear increases when operated for a long time. In addition, the PFPE oil itself is deteriorated and consumed by this reaction, so that the amount of the lubricant that can be used is remarkably reduced, and the synergistic effect is that the rolling bearing is burned in a short life.

It is required to obtain a longer life by suppressing this reaction and utilizing the inherent heat resistance and lubricity of PFPE oil. As countermeasures, improvement of seizure resistance and wear resistance of fluorine grease by silica blending (film formation) (see Patent Document 1), improvement of rolling fatigue characteristics by blending organic antimony or organic molybdenum (see Patent Document 2), bismuth Improvement of rolling fatigue characteristics by compounding (see Patent Document 3), improvement of wear resistance and rust prevention of fluorine grease by compounding of fluorine organophosphorus compound (see Patent Document 4), molybdenum disulfide, synthetic mica, etc. Improvement in wettability of fluorine grease by blending layered mineral powder, metal salt such as metal soap, metal oxide, diamond powder, carbon compound such as graphite, melamine cyanurate and amino acid compound (see Patent Document 5), modification Fluorine by blending undecane mixture, modified butane, Cu phthalocyanine, Ca sulfonate, etc. Prevent deterioration of the grease (refer to Patent Document 6) are known.
However, none of these has been made by paying attention to the reaction between fluorine and steel, but it has not been able to fundamentally improve the properties of fluorine-based grease having excellent high-temperature characteristics but erosion to metals.
JP 2005-97513 A JP 2000-303088 A JP-A-2005-42102 JP 2003-27079 A JP 2004-188607 A Japanese Patent Laid-Open No. 8-143883

  The present invention was made in order to cope with such problems, and is excellent in high-temperature durability, and has a long life utilizing the inherent heat resistance and lubricity of PFPE oil by suppressing the reaction between fluorine and steel. An object is to provide a rolling bearing.

  The rolling bearing of the present invention includes an inner ring and an outer ring, a plurality of rolling elements interposed between the inner ring and the outer ring, and a cage that holds the rolling elements, and PFPE oil is used as a base oil around the rolling elements. Fluorine-based lubricating grease containing fluororesin powder as a thickener is enclosed, and the cage is made of resin.

  The resin is a polyamide resin, a polyether ether ketone (hereinafter referred to as PEEK) resin, a polyphenylene sulfide (hereinafter referred to as PPS) resin, an aromatic polyimide (hereinafter referred to as PI) resin, a phenol resin, and a PPS. It is at least one resin selected from a mixed resin of a resin and a polyamideimide (hereinafter referred to as PAI) resin.

In the rolling bearing of the present invention, since fluorine-based lubricating grease is sealed around the rolling elements, the high-temperature durability is excellent, and the cage for holding the rolling elements is formed of resin. The reaction between fluorine and steel on the surface is suppressed, and a long life is achieved by utilizing the heat resistance and lubricity inherent in PFPE oil.
As a result, it can be suitably used as a rolling bearing used in automotive electrical equipment, office equipment and the like. Further, the amount of grease filled is relatively small, such as in a vacuum, and can be suitably used as a rolling bearing used under boundary lubrication conditions.

  When using fluorinated lubrication grease in rolling bearings, fluorine in the base oil reacts with steel (iron) on the frictional wear surface between the rolling elements and the cage or the new metal surface exposed by wear, and the base oil decomposes. It is believed that the steel wears out and shortens its life. This tendency is particularly remarkable under boundary lubrication conditions where frictional contact occurs. The present invention pays attention to such points, and in a rolling bearing using a fluorinated lubricating grease using PFPE oil as a base oil and fluororesin powder as a thickener, the cage is formed of resin, It is intended to extend the life by preventing contact and reaction.

In the rolling bearing of the present invention, the cage for holding the rolling elements is formed of resin. The synthetic resin constituting the cage is not particularly limited as long as it is a material having oil resistance, strong mechanical strength, and excellent wear resistance. Examples include polyethylene resins such as low density polyethylene, high density polyethylene, ultra high molecular weight polyethylene, modified polyethylene resins, water cross-linked polyolefin resins, polyamide resins, aromatic polyamide resins, polystyrene resins, polypropylene resins, silicone resins, urethanes. Resin, polytetrafluoroethylene resin, chlorotrifluoroethylene resin, tetrafluoroethylene / hexafluoropropylene copolymer resin, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer resin, vinylidene fluoride resin, ethylene / tetrafluoroethylene copolymer Polymer resin, polyacetal resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyphenylene ether resin, polycarbonate resin, aliphatic Liketone resin, polyvinylpyrrolidone resin, polyoxazoline resin, PPS resin, polyethersulfone resin, polyetherimide resin, PAI resin, PEEK resin, thermoplastic PI resin, thermosetting PI resin, epoxy resin, phenol resin, unsaturated Examples include polyester resins and vinyl ester resins. Moreover, the mixture of 2 or more types of materials chosen from the said synthetic resin, ie, a polymer alloy, etc. can be illustrated.
These synthetic resins can be blended with various fillers in the form of fibers and particles as necessary. As the fibrous filler, glass fiber or carbon fiber is preferable. In particular, carbon fiber is preferred when importance is attached to strength and wear resistance.
In the present invention, particularly preferred synthetic resins are polyamide resin, PEEK resin, PPS resin, mixed resin of PPS resin and PAI resin, PI resin, and phenol resin, and PI having excellent heat resistance particularly when used at high temperature. Resin, PEEK resin, and mixed resin of PPS resin and PAI resin are preferable.

  Polyamide resin is a general term for linear polymers containing amide groups in the molecular structure, and is a typical resin for engineering plastics. Polyamide resins include aliphatic polyamide resins such as polyhexamethylene adipamide (6,6-nylon) and polycaprolactam (6-nylon), polymetaphenylene isophthalamide, polyparaphenylene terephthalamide, polymeta Examples thereof include aromatic polyamide resins such as xylene adipamide (nylon MXD-6) and a condensation polymer of 1,9-nonanediamine and terephthalic acid (9T nylon), and these can be used alone or as a mixture.

PEEK resin is a crystalline aromatic thermoplastic resin with a polymer structure in which the benzene ring is in the para position and is linked to a rigid carbonyl group by a flexible ether bond, and has excellent heat resistance and impact resistance. Engineering plastics with wear resistance and sliding properties. The structure is shown in Chemical Formula 1. As a commercial item, PEEK150P (Victrex (VICTREX) company, brand name) is mentioned.

The PPS resin is a crystalline thermoplastic resin having a polymer structure shown in Chemical Formula 2 in which a benzene ring is connected at a para position by a sulfur bond. Examples of commercially available PPS resins include T4AG (Toprene, trade name), B160 (Tosoh Corporation, trade name), KPS W214 (Kureha Chemical Industry, trade name), and the like.

（式中、Ｒ₁は少なくとも１つのベンゼン環を含む３価の芳香族基、Ｒ₂は２価の有機基、Ｒ₃は水素、メチル基またはフェニル基を表わす。）
なお、化３式中の好ましいＲ₁を例示すると、下記の化４に示す通りである。

The PAI resin used in the present invention is represented by the following formula (3), and R ₁ is an aromatic group containing at least one benzene ring, of which two carbonyl groups are R ₁ Are bonded to adjacent carbon atoms in the benzene ring. The PAI used in the present invention may be a copolymer with a compound containing such a structure and another amide bond.

(Wherein R ₁ represents a trivalent aromatic group containing at least one benzene ring, R ₂ represents a divalent organic group, and R ₃ represents hydrogen, a methyl group or a phenyl group.)
A preferable example of R ₁ in the chemical formula 3 is as shown in the chemical formula 4 below.

（化５に示した基の一般式中、Ｙは１〜３の整数、Ｘ₄は１〜６個の炭素原子を有する脂肪族炭化水素基もしくは芳香族基である。） Moreover, preferable R ₂ in the chemical formula 3 is exemplified by a saturated aliphatic hydrocarbon group represented by — (CH ₂ ) _m — where m is 4 to 12, and the following chemical formula 5 .

(In the general formula of the group shown in Chemical formula 5, Y is an integer of 1 to 3, and X ₄ is an aliphatic hydrocarbon group or aromatic group having 1 to 6 carbon atoms.)

化６および化７に示す式中のＲ₄は化３に示す式中のＲ₂と同じである。
化６の式中のＡｒは、２価の芳香族基であり、その具体例としては、次の化８に示すものが挙げられる。

Moreover, it is more preferable to copolymerize a unit having the following structure with these PAI resins from the viewpoint of improving the compatibility with the PPS resin and further improving the melt fluidity.

R ₄ in the formulas shown in Chemical formulas 6 and 7 is the same as R ₂ in the formula shown in Chemical formula 3.
Ar in the formula 6 is a divalent aromatic group, and specific examples thereof include those shown in the following formula 8.

R ₅ shown in the formula 7 is a divalent aliphatic group, and specific examples thereof include — (CH ₂ ) _m —. More preferable — (CH ₂ ) _m — is m = 2 to 12, particularly preferably m = 4 to 12.

The copolymer consisting of the structure represented by Chemical Formula 3 and the structure represented by Chemical Formula 6 is preferably 10 to 70% by mole of Chemical Formula 3 and A composition composed of 90 to 30 mol% is preferred.
Further, the copolymer comprising the structure represented by Chemical Formula 3 and the structure represented by Chemical Formula 7 is preferably 10 to 50 mol% of Chemical Formula 3 with respect to a total of 100 mol% of the structures of Chemical Formula 3 and Chemical Formula 7. 7 is preferably composed of 90 to 50 mol%.
The copolymer having the structure of Chemical Formula 3, Chemical Formula 6 and Chemical Formula 7 is preferably one having a composition of Chemical Formula 3 of 10 to 70 mol%, Chemical Formula 6 of 1 to 89 mol%, and Chemical Formula 7 of 1 to 70 mol%. . The arrangement of each structure in the copolymer as described above may be random, block or alternating.
Such a PAI resin production method is well known as disclosed in patent publications such as US Pat. No. 3,625,911 and Japanese Patent Publication No. 50-33120. An aromatic tricarboxylic acid anhydride or a derivative thereof, and H ₂ N—R ₂ —NH ₂ , OCN—R ₂ —NCO (wherein R ₂ is the same as that described in Chemical Formula 3 above). The resulting organic diamine or derivative thereof is reacted in a polar organic solvent such as dimethylacetamide, dimethylformamide, or N-methylpyrrolidone at a predetermined temperature for a required time to form a polyamic acid or the like, which is heated or otherwise. Convert to imidized state.

上記の方法により得られるＰＡＩ樹脂は、溶融流動性が劣るので、より流動性の良いＰＡＩ樹脂を得るためには、芳香族トリカルボン酸無水物およびジイソシアネートから製造する方法を採用することが好ましい。また、重合の際において、特開平６−３２２０６０号公報に示されるようなアミド化とイミド化を段階的に進ませるような条件下で反応させることがより好ましい。
また、ＰＡＩ樹脂とＰＰＳ樹脂の相溶性を改良する目的でポリアミドイミドの前駆体を用いたり、第３成分としてイソシアネート化合物を添加することもできる。
ＰＡＩ樹脂はＰＰＳ樹脂と組み合わせて用いられるが、その配合割合は５〜６５容量％である。ＰＡＩ樹脂の配合量が、５容量％未満では、高温時の耐クリープ性の改善を充分に行なえないからであり、６５容量％をこえて多量に配合すると、他の成分であるＰＰＳ樹脂の絶縁性や成形容易性が充分に生かされ難くなり、溶融状態で流動性が低下し、射出成形が困難になる。また、射出成形時の無理抜き（アンダーカット）、軸受への組み込み性を考慮すると、組み合わせるＰＰＳ樹脂はセミ架橋（セミリニア）型や直鎖（リニア）型のものが好ましい。 As a PAI resin produced by this method, there is one represented by the following formula (10), and a commercially available product is Torlon (registered trademark) manufactured by Amoco USA.

Since the PAI resin obtained by the above method has poor melt fluidity, it is preferable to employ a method of producing from an aromatic tricarboxylic acid anhydride and diisocyanate in order to obtain a PAI resin having better fluidity. In the polymerization, it is more preferable to carry out the reaction under conditions that allow amidation and imidation to proceed stepwise as disclosed in JP-A-6-322060.
Further, for the purpose of improving the compatibility between the PAI resin and the PPS resin, a polyamideimide precursor may be used, or an isocyanate compound may be added as the third component.
PAI resin is used in combination with PPS resin, but the blending ratio is 5 to 65% by volume. This is because when the amount of PAI resin is less than 5% by volume, the creep resistance at high temperatures cannot be sufficiently improved. When the amount exceeds 65% by volume, insulation of PPS resin, which is another component, is not possible. Therefore, it is difficult to make full use of the properties and ease of molding, the fluidity is lowered in the molten state, and injection molding becomes difficult. In view of forced cutting (undercut) at the time of injection molding and ease of incorporation into the bearing, the PPS resin to be combined is preferably a semi-crosslinked (linear) type or a linear (linear) type.

The PI resin is a representative resin of a high heat resistance engineering plastic synthesized from, for example, an aromatic diamine and an aromatic tetracarboxylic acid dihydrate, and has high rigidity and excellent dimensional stability. The structure is shown in Chemical formula 11. Examples of commercially available products include AURUM (Mitsui Chemicals, trade name), Vespel (DuPont, trade name), Upilex (Ube Industries, trade name), and the like.

The phenol resin is a thermosetting resin excellent in heat resistance, electrical insulation, oil resistance and acid resistance obtained by reacting phenol and formaldehyde. The structure is shown in Chemical formula 12. Examples of commercially available products include Sumilite Resin (Sumitomo Bakelite Co., Ltd., trade name). These can be used as a laminate with cotton fabric.

The fluorine-based lubricating grease that can be used in the present invention uses PFPE oil as a base oil and fluorine resin powder as a thickener.
As the PFPE oil, any compound in which a hydrogen atom of an aliphatic hydrocarbon polyether is substituted with a fluorine atom can be used. Examples of such a PFPE oil include a PFPE oil having a side chain represented by the following chemical formula 13 and chemical formula 14 and a linear PFPE oil represented by chemical formula 15 to chemical formula 17. These can be used alone or in combination. n and m are integers.
Fomblin Y (product name of Montedison Co., Ltd.) is a commercially available product of Chemical Formula 13, and Krytox (trade name of DuPont Company) and Barrierta J Oil (trade name of Kluber Company) are commercially available. Fomblin Z (product name of Montedison Co., Ltd.) as the product, Fomblin M (product name of Montedison Co., Ltd.) as the commercial product of Chemical 16, and Demnum (trade name of Daikin) as the commercial product of Chemical 17 it can.

The fluororesin powder that is a thickener has a high affinity with the PFPE oil, and a powder having high temperature stability and chemical resistance can be used.
Examples of fluororesins include perfluorocarbons such as polytetrafluoroethylene (PTFE) resin, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) resin, and tetrafluoroethylene-hexafluoropropylene copolymer (FEP) resin. Fluorine resin is preferable, and polytetrafluoroethylene (PTFE) resin is particularly preferable because of its high temperature stability and chemical resistance.

  The fluorine-based lubricating grease used in the present invention preferably contains 70% to 90% by weight of PFPE oil and 10% to 30% by weight of fluororesin powder with respect to the total amount of lubricating grease. By blending within this range, the grease can be adjusted to a preferable consistency that can reduce the torque for a long time with less leakage as the grease in the rolling bearing.

  Regarding the seal of the rolling bearing of the present invention, a contact or non-contact rubber seal can be used in addition to the iron plate shield. Since this bearing is intended for high temperature use, it is preferable to use fluororubber as the rubber.

  The fluorine-based lubricating grease used in the present invention can contain known additives as necessary. As this additive, for example, antioxidants such as amine, phenol, sulfur, zinc dithiophosphate, extreme pressure agents such as chlorine, sulfur, phosphorus, zinc dithiophosphate, organic molybdenum, benzotriazole Examples thereof include metal deactivators such as polymethacrylate, polyisobutylene, and polystyrene, viscosity index improvers, wear inhibitors, detergent dispersants, and the like. These additives can be added alone or in combination of two or more.

  Further, the grease of the present invention can be used by using a fluorine-based grease as an essential component and mixing it with a urea-based grease.

An example of a rolling bearing according to the present invention is shown in FIG. FIG. 1 is a cross-sectional view of a deep groove ball bearing.
In the rolling bearing 1, an inner ring 2 having an inner ring rolling surface 2a on the outer peripheral surface and an outer ring 3 having an outer ring rolling surface 3a on the inner peripheral surface are arranged concentrically, and the inner ring rolling surface 2a and the outer ring rolling surface 3a A plurality of rolling elements 4 are arranged between the two. The cage 5 is configured to hold the plurality of rolling elements 4, and the seal member 6 is fixed to the outer ring 3 or the like. Of these, the cage 5 is made of resin. The cage 5 is made of resin and does not react even when it comes into contact with fluorine.

  In addition, this bearing does not ask | require a form, such as a deep groove ball bearing, an angular ball bearing, a thrust ball bearing, a roller bearing, a needle roller bearing (radial, thrust), and a tapered roller bearing. In addition, various methods can be used for manufacturing the resin cage, such as machining and injection molding, but it is preferable to employ injection molding with good productivity. As the shape of the cage, the most common crown type or machined type can be used for ball bearings, and cage type, comb type can be used for roller bearings, and cage type can be used for tapered roller bearings.

<Preparation of grease 1>
PFPE oil (DuPont brand name, Krytox GPL105, kinematic viscosity at 40 ° C 160 mm ² / sec) 67% by weight, fluororesin powder (DuPont brand name, Vidax) 33 wt. % And stirred, and then passed through a roll mill to obtain a semi-solid grease 1 which is a grease using fluororesin powder as a thickener and PFPE oil as a base oil. The consistency of grease 1 was 280.

<Preparation of grease 2>
PFPE oil (Solvay brand name, Fomblin M30, kinematic viscosity at 40 ° C, 159 mm ² / sec) 67 wt%, fluororesin powder (DuPont brand name, Vidax) 33 wt. %, And the mixture was passed through a roll mill to obtain a semi-solid grease 2 which was a grease using fluororesin powder as a thickener and PFPE oil as a base oil. The consistency of grease 2 was 280.

Reference Example 1 and Reference Example 3
Rolling bearings for testing were manufactured with 6204 bearings using the bearing configuration and grease shown in Table 1. A crown-type cage in which PEEK resin (manufactured by Victrex Co., Ltd .: PEEK450CA30) containing 30% by weight of carbon fiber was injection-molded was used. SUJ2 was used for the material of the inner and outer rings and the rolling elements. The seal is an iron plate shield.

Rolling bearings were manufactured by enclosing grease in a bearing 6204ZZ cleaned with petroleum benzine so that the volume of the entire space volume was 38% by volume. The obtained rolling bearing was evaluated in a high temperature durability test.
In the high temperature durability test, the bearing was rotated at a radial load of 67 N, a thrust load of 67 N, a rotation speed of 10000 rpm, and an ambient temperature of 200 ° C., and the time until the motor stopped due to overload was measured. The results are shown in Table 1.

Reference example 2
A high temperature durability test was conducted in the same manner as in Reference Example 1 except that polyimide resin (Mitsui Chemicals: Aurum) was used as the resin cage material. The results are shown in Table 1.

Example 1
PPS resin (30 parts by weight of PAI resin polymerized in N-methylpyrrolidone under the conditions of removing CO ₂ from 50 mol% of trimellitic anhydride and 50 mol% of 2,4-tolylene diisocyanate as raw materials Dainippon Ink and Chemicals, Inc .: Linear PPS Resin LR-03) is the same as Reference Example 1 except that a resin mixture consisting of PAI resin and PPS resin blended with 45 parts by weight and 25 parts by weight of glass fiber is used. A high temperature durability test was conducted. The results are shown in Table 1.

Comparative Example 1 and Comparative Example 2
Rolling bearings for testing were manufactured with 6204 bearings using the bearing configuration and grease shown in Table 1. The same high temperature endurance test as the reference example was conducted. The results are shown in Table 1.

表１に示すように、実施例１の樹脂製保持器を用いた転がり軸受は、各比較例よりも高温耐久試験に優れた。

As shown in Table 1, the rolling bearing using the resin cage of Example 1 was superior in the high temperature durability test than each comparative example .

  Since the rolling bearing of the present invention does not react with fluorine and the resin cage and has a long life by utilizing the inherent heat resistance and lubricity of PFPE oil, it is used in automotive electrical equipment, office equipment, etc. It can be suitably used as a rolling bearing. Further, the amount of grease filled is relatively small, such as in a vacuum, and can be suitably used for rolling bearings used under boundary lubrication conditions.

It is sectional drawing of a deep groove ball bearing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rolling bearing 2 Inner ring 3 Outer ring 4 Rolling element 5 Cage 6 Seal member 7 Fluorine lubrication grease

Claims (5)

A rolling bearing comprising an inner ring and an outer ring, a plurality of rolling elements interposed between the inner ring and the outer ring, and a cage for holding the rolling element,
Fluorine-based lubricating grease containing perfluoropolyether oil as a base oil and fluororesin powder as a thickener is enclosed around the rolling elements,
Resin whose main component is a mixed resin of a semi-crosslinked or linear polyphenylene sulfide resin and a polyamideimide resin produced from an aromatic tricarboxylic acid anhydride or derivative thereof and diamine or derivative thereof. A rolling bearing, characterized by being a cage obtained by injection molding a mixture . The rolling bearing according to claim 1, wherein the polyamideimide resin is produced from an aromatic tricarboxylic acid anhydride and diisocyanate .   The rolling bearing according to claim 1, wherein the polyamideimide resin precursor is used in the resin mixture, or an isocyanate compound is included as a third component.   4. The rolling bearing according to claim 1, wherein a blending ratio of the polyamideimide resin in the mixed resin is 5 to 65% by volume. 5.   The rolling bearing according to any one of claims 1 to 4, wherein the polyamide-imide resin is represented by any one of the following chemical formulas (10).

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