JP5516686B2 - Rolling bearing - Google Patents

Description

  The present invention relates to a rolling bearing having a long life in an environment where mist or droplets in a corrosive aqueous solution such as an acid or an alkali or a corrosive aqueous solution exist.

Generally, rolling transceiving includes an inner ring having an inner ring raceway on an outer peripheral surface, an outer ring having an outer ring raceway on an inner peripheral surface, a plurality of rolling elements provided between the inner and outer ring raceways, and a plurality of these rolling elements. Each rolling element is constituted by a cage that guides and holds between the raceways of the inner and outer rings. There is also a rolling bearing having a total rolling element structure that does not include a cage.
Such rolling bearings are usually lubricated by circulatingly supplying lubricating oil or grease to the bearings or enclosing them inside the bearings. Further, in an environment where mists and droplets of corrosive aqueous solutions such as acids and alkalis exist, it is necessary to prevent these mists and droplets from entering the bearing. Therefore, for example, in Japanese Utility Model Laid-Open Nos. 55-34002 and 57-56218, lubrication is performed by filling the bearing space with lubricating oil or grease, and a contact seal or labyrinth seal is provided on the bearing. Thus, a technique for preventing water or the like from entering the bearing is disclosed.

  However, contact type seals wear on the lip part of the seal as the bearing rotates, which may cause a gap between the lip part and the seal surface, and completely prevent water from entering through this gap. I can't do it. Similarly, the labyrinth seal cannot completely prevent water or the like from entering through the gap. For this reason, even if a contact-type seal or labyrinth seal is provided, water or the like enters the bearing from the gap caused by wear of the contact-type seal or the labyrinth seal, and the lubricating oil or grease softens. Lubricating oil and grease may splash outside the bearing and contaminate the outside environment of the bearing.

Therefore, for example, when a clean environment is required such as a clean room, a semiconductor device manufacturing apparatus, a liquid crystal panel manufacturing apparatus, a hard disk manufacturing apparatus, etc., lubricating oil or grease cannot be used to lubricate rolling bearings.
Therefore, as a lubricating method for rolling bearings, a method that does not use lubricating oil or grease has been conventionally proposed. For example, Japanese Patent Publication No. 8-26894 and Japanese Patent No. 2709119 include a stainless steel inner ring and outer ring, and a fluororesin (a fluororesin alone or tetrafluorocarbon containing a potassium titanate whisker short fiber having a diameter of 2 μm or less). A rolling bearing composed of a cage made of (ethylene-ethylene copolymer) and a rolling element made of hard carbon is disclosed. In this bearing, due to the frictional contact between the cage and the rolling element, the fluororesin constituting the cage is transferred to the rolling element, the inner ring, and the outer ring, and a thin lubricating film made of the fluororesin is formed.
Japanese Patent Publication No. 8-26894 Japanese Patent No. 2709119

However, rolling bearings used in corrosive aqueous solutions or in environments where there is mist or splashes of corrosive solutions completely prevent corrosion such as rust even if the inner and outer rings are made of stainless steel. I can't do it. And since the wear of a bearing structural member and the increase in surface roughness are accelerated by corrosion, a sufficiently long bearing life cannot be obtained.
That is, a rolling bearing composed of stainless steel inner and outer rings, a fluororesin cage, and a hard carbon rolling element does not cause contamination of the external environment by the lubricant. Even if a contact-type seal or labyrinth seal is provided, the lubrication will be maintained over a long period of time if the environment is used in a corrosive aqueous solution such as acid or alkali, or in the presence of mist or droplets of corrosive solution. Thus, it is difficult to obtain a sufficiently long bearing life.

  The present invention has been made paying attention to such problems of the prior art, and even when used in a corrosive aqueous solution such as acid or alkali or in an environment where mist or droplets of the corrosive aqueous solution exist, It is an object of the present invention to provide a rolling bearing that can maintain lubricity for a long period of time and does not cause contamination of the external environment due to the lubricant.

  In order to solve the above problems, a rolling bearing according to an aspect of the present invention is a rolling bearing including an inner ring, an outer ring, and a rolling element made of a corrosion-resistant material, and a cage made of a resin composition. At least one is formed by ETFE, PVDF, PFA, or FEP, which is a fluororesin that can be melt-molded, or ETFE, PVDF, PFA, or FEP, which is a fluororesin that can be melt-molded, and carbon fiber, titanium It consists of a fibrous filler that is an acid potassium whisker, an aluminum borate whisker, or an aramid fiber, and is formed and held by a resin composition having a content of the fibrous filler of 5% by weight to 40% by weight. The vessel is a resin mainly composed of a fluororesin that can be melt-molded and to which a fibrous filler and / or a solid lubricant is added. To provide a rolling bearing, characterized in being formed by Narubutsu.

  According to the rolling bearing of the above aspect, the inner ring and / or the outer ring is formed of ETFE, PVDF, PFA, or FEP which is a fluororesin that can be melt-molded, or ETFE that is a fluororesin that can be melt-molded. , PVDF, PFA, or FEP and a fibrous filler that is carbon fiber, potassium titanate whisker, aluminum borate whisker, or aramid fiber, and the fibrous filler content is 5 wt% or more and 40 wt% The cage is formed of the following resin composition, and the cage is formed of a resin composition containing, as a main component, a fluororesin that can be melt-molded and added with a fibrous filler and / or a solid lubricant. Therefore, a rolling shaft in which the inner ring and the outer ring are formed of stainless steel and the cage is formed of a resin composition other than the resin composition. Compared, corrosion resistance when corrosive aqueous solution and mist and splash corrosive aqueous acid or alkali or the like is used in an environment that exists as high as.

  According to the rolling bearing of the above aspect, the bearing component (the inner ring and / or the outer ring and the cage) made of fluororesin has self-lubricating properties, and when these are in frictional contact with the rolling element, the bearing configuration Since the fluororesin that forms the member is transferred to the rolling elements and a thin lubricating film is formed of the fluororesin, the lubricity can be maintained over a long period of time without supplying lubricating oil or grease inside the bearing. Can do. That is, according to this rolling bearing, since it is not necessary to supply lubricating oil or grease into the bearing, the external environment is not contaminated by the lubricant.

Furthermore, since the inner ring and / or outer ring and cage formed of a fluororesin capable of melt molding can be formed by injection molding or the like excellent in mass productivity, the rolling bearing of the one aspect is The manufacturing cost can be reduced as compared with a rolling bearing in which the inner ring and the outer ring are formed of stainless steel and the cage is formed of a resin composition other than the resin composition.
Further, the raceways of the inner ring and the outer ring formed of a fluororesin that can be melt-molded can be finished by machining. Then, by finishing the raceway surface by machining, the roundness of the raceway surface can be made higher than when finishing by machining, so that the rolling elements can rotate smoothly over a longer period. In this case, the roundness is preferably 20 μm or less, more preferably 10 μm or less, and further preferably 5 μm or less.
A rolling bearing according to an aspect of the present invention is a rolling bearing including an inner ring, an outer ring, and a rolling element made of a corrosion-resistant material, and a cage made of a resin composition. At least one of the inner ring and the outer ring can be melt-molded. PVDF, which is a simple fluororesin, and fibrous filler, which is carbon fiber or potassium titanate whisker, the synthetic resin component is composed only of PVDF, and the content of the fibrous filler is 5% by weight to 40% by weight. The inner ring and outer ring raceway surfaces are finished by machining, and the cage is formed of a resin composition mainly composed of a fluororesin that can be melt-molded. Features.

  Examples of the fluororesin that can be melt-molded include tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (hereinafter abbreviated as “PFA”), tetrafluoroethylene-ethylene copolymer (hereinafter abbreviated as “ETFE”), poly Vinylidene fluoride (hereinafter abbreviated as “PVDF”), tetrafluoroethylene-hexafluoropropylene copolymer (hereinafter abbreviated as “FEP”), polychlorotrifluoroethylene (hereinafter abbreviated as “PCTFE”), chlorotri Fluoroethylene-ethylene copolymer (hereinafter abbreviated as “ECTFE”) and the like can be mentioned, and these can be used alone or in combination of two or more thereof. Among these, PFA, ETFE, PVDF, and FEP used in the rolling bearing of the above aspect are excellent in self-lubricating property and corrosion resistance. Therefore, in a corrosive aqueous solution such as acid or alkali, It is particularly preferable as a bearing material used in an environment where splashes are present.

In the rolling bearing of the present invention, the material of the rolling element is not particularly limited as long as it is made of a corrosion-resistant material. For example, stainless steel represented by SUS440C, LNS125, ES1, SUS630 can be used. Or it is preferable that the whole rolling element is formed with ceramics or glass. Ceramics that can be used in this case include silicon nitride (Si ₃ N ₄ ), silicon carbide (SiC), sialon, partially stabilized zirconia (ZrO ₂ ), hard carbon, and alumina (Al ₂ O ₃ ). Etc.

  Note that LNS125 and ES1 are NSK's unique standard numbers. LNS125 has a C content of 0.6% to 0.7% by weight, a Si content of 1.00% by weight or less, a Mn content of 1.00% by weight or less, and a Cr content of 12%. 0.0 to 13.5 wt% martensitic stainless steel. ES1 has a C content of 0.44% to 0.46% by weight, a Si content of 0.2% to 0.4% by weight, and a Mn content of 0.2% to 0.4%. It is a martensitic stainless steel having 4 wt%, Cr content of 12.8 wt% to 13.2 wt%, and N content of 0.09 wt% to 0.18 wt%.

  When the surface of the rolling element or the entire rolling element is made of ceramics, the corrosion resistance becomes much higher than when the rolling element is made of stainless steel. For this reason, even if a corrosive aqueous solution such as acid or alkali enters, it is hardly corroded. Even if the lubricating film is not sufficiently formed on the rolling elements by the above-mentioned transfer due to the intrusion of the corrosive aqueous solution, the rolling elements and the tracks can be used as long as the surface or the whole of the rolling elements is formed of ceramics. Adhesion is unlikely to occur with the surface. Therefore, the operation of the bearing continues for a long time even if the corrosive aqueous solution enters.

In the rolling bearing according to the aspect, the cage is formed of a resin composition in which a solid lubricant and / or a fibrous filler is added to a melt-moldable fluororesin.
Examples of the solid lubricant that can be blended in such a resin composition include polytetrafluoroethylene (PTFE) powder, graphite, hexagonal boron nitride (hBN), fluorine mica, melamine cyanurate (MCA), and a layered crystal structure. An amino acid compound (N-lauro / L-lysine) having benzene, fluorinated graphite, fluorinated pitch, molybdenum disulfide (MoS ₂ ) and the like. When an inner ring, an outer ring, and a cage are formed from a resin composition mainly composed of a fluororesin or a heat-resistant resin blended with such a solid lubricant, these self-lubricating properties are increased and transfer is performed. Wear of the formed lubricating film is reduced.

  The average particle size of the solid lubricant that can be blended in the resin composition is not particularly limited, but is preferably 0.1 μm or more and 60 μm or less. In the case of a small particle having an average particle size of less than 0.1 μm, when mixed with a fluororesin or a heat resistant resin as a main component, aggregation between the particles may occur and the dispersion of the particles may be non-uniform. On the other hand, in the case of particles having a large particle diameter exceeding 60 μm, the smoothness of the surface of the molded body is lowered and the strength is lowered, so that the life of the bearing may be shortened. A more preferable range of the average particle size of the solid lubricant that can be blended in the resin composition is 0.1 μm or more and 20 μm or less, and a more preferable range is 0.1 μm or more and 10 μm or less.

  When a solid lubricant is blended in the resin composition, the content in the resin composition is preferably 5% by weight or more and 40% by weight or less (more preferably 30% by weight or less). If it is less than 5% by weight, the action of the solid lubricant is not substantially obtained. Moreover, even if it exceeds 40% by weight, not only a further improvement of the lubricating action can not be expected, but also the wear of the inner ring, outer ring, and cage which are the molded body due to the decrease in mechanical strength of the molded body. May increase and the life of the bearing may be shortened.

  Examples of the fibrous filler that can be blended in the resin composition include aluminum borate whisker, potassium titanate whisker, carbon whisker, aramid fiber, aromatic polyimide fiber, liquid crystal polyester fiber, graphite whisker, glass fiber, carbon fiber, and boron. Examples thereof include fiber, silicon carbide whisker, silicon nitride whisker, alumina whisker, aluminum nitride whisker, and wollastonite. When an inner ring, an outer ring, and a cage are formed from a resin composition mainly composed of a fluororesin or heat-resistant resin mixed with such a fibrous filler, the mechanical strength and wear resistance of the molded body are high. Thus, deformation and wear during rotation of the bearing can be suppressed. As a result, the bearing can operate stably over a long period of time.

  The fibrous filler that can be blended in the resin composition is preferably one having an aspect ratio of 3 or more and 200 or less. When the fibrous filler has an aspect ratio of less than 3, the reinforcing effect of the molded body is not sufficiently exhibited. When the aspect ratio exceeds 200, uniform dispersion during mixing becomes extremely difficult. Further, the fiber diameter of the fibrous filler is not particularly limited, but the average fiber diameter is preferably 0.2 μm or more and 30 μm or less, more preferably 0.3 μm or more and 20 μm or less, and still more preferably 0.3 μm or more. 5 μm or less.

  When a fibrous filler is blended in the resin composition, the content in the resin composition is preferably 5% by weight or more and 40% by weight or less. If it is less than 5% by weight, the effect of improving the mechanical strength of the molded product is hardly recognized. Even if it exceeds 40% by weight, not only a further improvement in mechanical strength can be expected, but also the fluidity when melt-molding the resin composition is remarkably lowered. A more preferable range of the content of the fibrous filler in the resin composition is 10% by weight or more and 30% by weight or less.

  In addition, the total content of the solid lubricant and the fibrous filler in the resin composition is 10% by weight or more and 50% by weight or less from the viewpoint of fluidity during melt molding and mechanical strength of the molded body. Is preferred. Even when the content of each of the solid lubricant and the fibrous filler in the resin composition is 40% by weight or less, if the total content of both exceeds 50% by weight, the resin composition is melt-molded. In some cases, the fluidity and the mechanical strength of the molded body are significantly reduced.

In the case where a fibrous filler is blended in the resin composition, a silane or titanate coupling agent is used for the purpose of increasing adhesion with the resin as a base material or dispersing it uniformly in the base material. May be subjected to surface treatment, or may be subjected to surface treatment according to other purposes.
In the rolling bearing of the present invention, the resin composition forming the inner ring, the outer ring, or the rolling element preferably contains a liquid crystal polymer. That is, the invention according to another aspect is characterized in that, in the rolling bearing of the above aspect, the resin composition constituting the cage contains a liquid crystal polymer.

By adding a liquid crystal polymer to a fluoro-resin or heat-resistant resin that can be melt-molded, the fluidity of the material during molding is improved, and the solidification rate of the resin is increased by cooling in the mold, so that burrs are eliminated. It becomes difficult to occur and injection molding can be performed at a relatively low injection pressure. That is, moldability such as PEEK having relatively poor fluidity is improved.
Also, by adding a liquid crystal polymer to a melt-formable fluororesin or heat-resistant resin, the melt-moldable fluororesin or heat-resistant resin and the liquid crystal polymer are fibrillated at the time of kneading or molding the resin composition. In order to exert a self-reinforcing effect, the inner ring, the outer ring, or the cage formed of this resin composition can obtain sufficient mechanical strength and wear resistance.

  Examples of the liquid crystal polymer that can be used in the present invention include semi-aromatic liquid crystal polyester and wholly aromatic liquid crystal polyester. The semi-aromatic liquid crystal polyester has a basic structure represented by the following chemical formula 1. This basic structure consists of two repeating units. A semi-aromatic liquid crystal polyester in which a third component (2,6-naphthalenedicarboxylic acid component) is copolymerized in this basic structure can also be used.

市販されている半芳香族液晶ポリエステルとしては、ユニチカ製の「ＲＯＤＲＡＮ」ＬＣ−５０００およびＬＣ−５０５０ＧＭ、出光石油化学製の「出光ＬＣＰ」ＬＣＰ２００ＪおよびＬＣＰ２１０Ｊ、三菱化学製の「ＮＯＶＡＣＣＵＲＡＴＥ」Ｅ３１０、川崎製鉄製「Ｋ―ＬＣＰ」等を例示することができる。

Commercially available semi-aromatic liquid crystalline polyesters include “RODRAN” LC-5000 and LC-5050GM manufactured by Unitika, “Idemitsu LCP” LCP200J and LCP210J manufactured by Idemitsu Petrochemical, “NOVACCURATE” E310 manufactured by Mitsubishi Chemical, and Kawasaki Steel Examples thereof include “K-LCP” manufactured by the Company.

  The wholly aromatic liquid crystal polyester has a basic structure represented by the following chemical formula 2, chemical formula 3, chemical formula 4, and chemical formula 5. These basic structures consist of two or three repeating units.

  Examples of the wholly aromatic liquid crystalline polyester represented by Chemical Formula 2 include “XYDAR” SRT300 and SRT500 manufactured by Amoco, “Sumika Super LCP” E2000 and E6000 manufactured by Sumitomo Chemical, “HAG” and “ HBG "etc. can be illustrated. Examples of the wholly aromatic liquid crystal polyester represented by Chemical Formula 3 include “VECTRA” A950 manufactured by Hoechst Celanese, “UENO LCP” 1000 and 2000 manufactured by Ueno Pharmaceutical, and the like.

  Examples of the wholly aromatic liquid crystal polyester represented by Chemical Formula 4 include “HX-2O00 and HX-3000” manufactured by Du Pont, “GRANLAR” manufactured by Granmont, and the like. Examples of the wholly aromatic liquid crystal polyester represented by Chemical Formula 5 include “ULTRAX” KR400O manufactured by BASF, “VICTREX SRP” 1500G and 2300G manufactured by ICI, “POLYSTAL” manufactured by Bayer, and the like.

  Although the content rate of the liquid crystal polymer in this resin composition is not specifically limited, It is preferable that they are 5 weight% or more and 50 weight% or less. If the content is less than 5% by weight, the above-described functions (fluidity of the material at the time of molding, molding processability, strength characteristics) obtained with the inclusion of the liquid crystal polymer cannot be substantially obtained. When the blending amount exceeds 50% by weight, not only the improvement in fluidity, molding processability and strength properties can be expected, but also the amount of other additive components is relatively reduced, so that the effect of other additive components is exerted. Not enough.

In the case where the resin composition contains a liquid crystal polymer and a solid lubricant and / or a fibrous filler, in the resin composition from the viewpoint of fluidity during melt molding and mechanical strength of the molded body. The total content of the liquid crystal polymer and the solid lubricant and / or fibrous filler is preferably 10% by weight or more and 60% by weight or less. In this resin composition, even if the content of the liquid crystal polymer and the content of the solid lubricant and / or the fibrous filler are 40% by weight or less, if the total content of both exceeds 60% by weight, the resin In some cases, the fluidity and the mechanical strength of the molded body when the composition is melt-molded are significantly reduced.
In the rolling bearing of the present invention, the resin composition forming the inner ring, the outer ring, and the rolling element includes, for example, an antioxidant, a heat stabilizer, an ultraviolet absorber, and a light within a range that does not impair the purpose of the present invention. Various additives such as a protective agent, a flame retardant, an antistatic agent, a fluidity improver, an amorphous tackifier, a crystallization accelerator, a nucleator, a pigment, and a dye may be added.

  A mixing method in the case where a solid lubricant or a fibrous filler is blended with the resin composition is not particularly limited, and the main component fluororesin is melted, and a solid lubricant, a fibrous filler, or an additive is contained therein. , And may be mixed while adding one by one. Alternatively, all of these materials may be preliminarily mixed in a mixer such as a Henschel mixer, a tumbler, a ribbon mixer, or a ball mill, and then supplied to the melt mixer for melt kneading. As the melt mixer, known melt kneaders such as a single-screw or twin-screw extruder, a kneading roll, a pressure kneader, a Banbury mixer, and a brander plastograph can be used. The temperature at the time of melt kneading may be a temperature within a range where the main component resin is sufficiently melted and does not decompose.

  According to the rolling bearing of the present invention, compared to the conventional corrosion-resistant rolling bearing, the corrosion resistance when used in a corrosive aqueous solution such as acid or alkali and in an environment where mist or droplets of the corrosive aqueous solution exists is high. Become. Further, the lubricity can be maintained for a long time without supplying lubricating oil or grease into the bearing. As a result, there is no need to supply lubricating oil or grease into the bearing, so that the external environment is not contaminated by the lubricant.

In addition, the use of melt-moldable fluororesin or heat-resistant resin as the material for the inner ring, outer ring, and cage makes it possible to form these by injection molding with excellent mass productivity. Cost can be reduced.
Furthermore, by adding a liquid crystal polymer to the resin composition forming the inner ring, outer ring, or rolling element, the moldability, mechanical strength, and wear resistance of the inner ring, outer ring, or rolling element are increased.

It is a schematic sectional drawing which shows the rolling bearing corresponded to one Embodiment of this invention. It is a graph which shows the relationship between the content rate of the PTFE powder in the resin composition which comprises the inner ring | wheel of a bearing, and the outer ring | wheel obtained from the test result in embodiment, and the lifetime of a bearing. It is a graph which shows the relationship between the content rate of the potassium titanate whisker in the resin composition which comprises the inner ring | wheel of a bearing, and the outer ring | wheel obtained from the test result in embodiment, and the lifetime of a bearing. It is a graph which shows the relationship between the content rate of the carbon fiber in the resin composition which comprises the inner ring | wheel of a bearing, and the outer ring | wheel obtained from the test result in embodiment, and the lifetime of a bearing. The relationship between the content rate of the PTFE powder in the resin composition (containing potassium titanate whisker at a constant ratio) obtained from the test results in the embodiment and containing the inner ring and the outer ring of the bearing and the life of the bearing is shown. It is a graph. The graph which shows the relationship between the content rate of the PTFE powder in the resin composition (it contains carbon fiber by a fixed ratio) which comprises the inner ring | wheel and outer ring | wheel of a bearing obtained from the test result in embodiment, and the lifetime of a bearing is there. The relationship between the content rate of the potassium titanate whisker in the resin composition (containing PTFE powder at a certain ratio) constituting the inner ring and the outer ring of the bearing and the life of the bearing obtained from the test results in the embodiment is shown. It is a graph. It is a graph which shows the relationship between the content rate of the liquid crystal polymer in the resin composition which comprises the inner ring | wheel and outer ring | wheel of a bearing, and the lifetime of a bearing obtained from the test result in embodiment. The graph which shows the relationship between the content rate of the PTFE powder in the resin composition (it contains liquid crystal polymer in a fixed ratio) which comprises the inner ring | wheel and outer ring | wheel of a bearing obtained from the test result in embodiment, and the lifetime of a bearing is there. The relationship between the content rate of the potassium titanate whisker in the resin composition (containing liquid crystal polymer in a certain ratio) constituting the inner ring and the outer ring of the bearing and the life of the bearing obtained from the test results in the embodiment is shown. It is a graph. The content of PTFE powder in the resin composition (containing liquid crystal polymer and potassium titanate whisker at a constant ratio) obtained from the test results in the embodiment, and the life of the bearing It is a graph which shows a relationship.

Hereinafter, embodiments of the present invention will be described in detail using specific examples.
[No. 1 to 86]
As rolling bearings for testing, No. 1 to No. 41, No. 51 to No. 53, No. 54 to No. 68, and No. 73 to No. 86 are single rows corresponding to the nominal number 6000. A deep groove ball bearing (inner diameter 10 mm, outer diameter 26 mm, width 8 mm) was assembled. As shown in FIG. 1, this bearing is composed of an outer ring 1, an inner ring 2, a ball (rolling element) 3, and a crown-shaped cage 4, and no seal is provided. In addition, as rolling bearings of No. 42 to No. 50 and No. 69 to No. 72, the inner ring, outer ring, and balls having the same shape as the deep groove ball bearing are used, and a seal is provided without using a cage. Not assembled all ball bearings.

The constituent materials of the inner ring, outer ring, rolling element, and cage of each bearing are shown in Tables 1 to 4 below. The same material was used for the inner ring and the outer ring for each sample. The inner ring, outer ring, and cage made of resin alone or resin composition were produced by injection molding. Moreover, what was shown below was used as resin and an additive.
Fluoropolymer that can be melt-molded;
PFA: “Neoflon PFA AP-201” manufactured by Daikin Industries
ETFE: “Neofluon ETFE EP-520” manufactured by Daikin Industries
PVDF: “Kureha KF Polymer T- # 1000” manufactured by Kureha Chemical Industry
Or "Kureha KF Polymer T- # 850"
Heat-resistant resin that can be melt-molded;
PEN: “ID300” made by Idemitsu Material
PEEK: "Victorex PEEK 150G" manufactured by Victorex
PEEK-PBI: Hoechst Celanese “Cerasol TU-60”
Fibrous filler;
Aluminum borate whisker (abbreviated as “ABW” in Tables 1 to 3)
: "Arborex YS1" manufactured by Shikoku Chemicals,
Average fiber diameter 0.5-1.0 μm, length 10-30 μm
Potassium titanate whisker (abbreviated as “KTW” in Tables 1 to 4)
: "Tismo D-101" manufactured by Otsuka Chemical,
Average fiber diameter 0.3-0.6 μm, length 10-20 μm
Carbon fiber: “Kureka Chop M-102S” manufactured by Kureha Chemical Industry,
Average fiber diameter 14.5μm, length 0.2mm
Aramid fiber: “Kinol fiber KF02BT” manufactured by Gunei Chemical Industry Co., Ltd.
Average fiber diameter 14.0μm, length 0.2mm
Solid lubricants;
PTFE: “Lublon L-5” manufactured by Daikin Industries, powder with an average particle size of 0.2 μm MCA: Melamine silanurate manufactured by Mitsubishi Chemical, powder with an average particle size of 2.0 μm Fluorinated pitch: Fluorinated pitch, average particle manufactured by Osaka Gas Powder with a diameter of 1.0 μm Fluorine mica: “Synthetic Mica PDM-9WA” manufactured by Topy Industries,
Average particle size 8.0μm

  Here, when using the resin composition which consists of a fluororesin and a fibrous filler, the content rate of the fluororesin in a resin composition was 80 weight%, and the content rate of the fibrous filler was 20 weight%. . When using the resin composition which consists of a fluororesin and a solid lubricant, the content rate of the fluororesin in a resin composition was 80 weight%, and the content rate of the solid lubricant was 20 weight%. When using a resin composition comprising a fluororesin, a fibrous filler, and a solid lubricant, the content of the fluororesin in the resin composition is 70% by weight, the content of the fibrous filler is 10% by weight, The solid lubricant content was 20% by weight.

  The resin composition was mixed as follows in order to prevent breakage of the fibrous filler. That is, first, the material excluding the fibrous filler is dry-mixed with a Henschel mixer, and then the mixture is put into a twin screw extruder. The fibrous filler is put into a twin-screw extruder from a fixed side feeder and kneaded with the mixture. This kneaded product is extruded and granulated into pellets. The resin composition pellets or resin single pellets thus obtained were supplied to an injection molding machine, and injection molding was performed under optimal injection conditions for each material.

In the rolling bearings of No. 45 to No. 50 and No. 70 to No. 72, rolling elements formed of ceramics and rolling elements formed of PTFE are alternately arranged. In the rolling bearing No. 69, only rolling elements made of ceramics (SiC) are arranged.
Each assembled rolling bearing was subjected to a rotation test in a 1N sulfuric acid aqueous solution using a bearing rotation tester manufactured by NSK Ltd. under the following conditions to evaluate the bearing life based on the vibration value. That is, the radial vibration generated in the bearing was constantly measured during the rotation test, and the test was stopped when the vibration value became three times or more the initial value, and the total number of rotations up to that time was regarded as the life. Note that all the rolling bearings No. 1 to No. 86 were not lubricated with grease.

<Rotational test conditions>
Atmospheric pressure: Atmospheric pressure Atmospheric temperature: Normal temperature Radial load: 49N
Rotation speed: 300rpm
Further, in order to compare the life of each test bearing, a relative value was calculated when the life of No. 51 corresponding to a conventional all-metal rolling bearing was “1”. These results are also shown in Tables 1 to 4 below.

  As can be seen from these tables, the bearings of No. 1 to No. 50 and No. 54 to No. 85 corresponding to the examples of the present invention are No. 51 to No. 53, No. 5 corresponding to the comparative examples. Compared to 86 bearings, the service life in a corrosive environment is significantly increased. Further, the bearings of No. 5 to No. 7, No. 12 to No. 50, and No. 57 to 72 whose rolling elements are made of ceramics or glass are No. 1 to No. whose rolling elements are made of metal. It can be seen that the life in a corrosive environment is longer than the bearings of No. 4, No. 8 to No. 11, and No. 54 to 56.

   The bearings of No. 73 to No. 85 are composed of a heat-resistant resin (except fluororesin) that can be melt-molded as a main component, and a resin composition to which a fibrous filler and / or a solid lubricant is added. This is an embodiment in which an outer ring and a cage are formed. The bearing of No. 86 is a comparative example in which the inner ring and the outer ring are formed of PEEK corresponding to a heat-resistant resin (excluding fluororesin) that can be melt-molded. From the results in Table 4, it can be seen that the bearings No. 73 to No. 85 have a significantly longer life in a corrosive environment than the bearing No. 86.

Furthermore, an inner ring and an outer ring were made from a resin composition containing PFA, ETFE, PVDF, PEEK, or PEN as a main component and blended with various ratios of PTFE powder as a solid lubricant. A mixture (ETFE: KTW = 80: 20) of these inner rings and outer rings (same material as the inner ring), rolling elements made of silicon nitride (Si ₃ N ₄ ), ETFE and potassium titanate whiskers (KTW). The same rolling bearing as described above was assembled using the cage produced by the above.

  Using these bearings, a rotation test in the above corrosive aqueous solution (1N sulfuric acid aqueous solution) was performed, and the bearing life was evaluated based on the vibration value by the same method. And the relationship between the content rate of the solid lubricant in the resin composition which comprises an inner ring | wheel and an outer ring | wheel, and lifetime was investigated. The results are shown graphically in FIG. “○” indicates that the main component is PFA, “Δ” indicates that the main component is ETFE, “□” indicates that the main component is PVDF, and “◇” indicates that the main component is PEEK. "Shows the result when the main component is PEN. The life shown in FIG. 2 is a relative value with the life of No. 51 as “1” in the same manner as described above.

As can be seen from this figure, the life of the bearing in a corrosive aqueous solution is increased by blending PTFE powder as a solid lubricant with a content of 40% by weight or less in the resin composition constituting the inner ring and the outer ring. be able to.
Furthermore, an inner ring and an outer ring were prepared from a resin composition containing PFA, ETFE, PVDF, PEEK, or PEN as a main component and potassium titanate whisker as a fibrous filler in various ratios. A mixture (ETFE: KTW = 80: 20) of these inner rings and outer rings (same material as the inner ring), rolling elements made of silicon nitride (Si ₃ N ₄ ), ETFE and potassium titanate whiskers (KTW). The same rolling bearing as described above was assembled using the cage produced by the above.

  Using these bearings, a rotation test in the above corrosive aqueous solution (1N sulfuric acid aqueous solution) was performed, and the bearing life was evaluated based on the vibration value by the same method. And the relationship between the content rate of the fibrous filler in the resin composition which comprises an inner ring | wheel and an outer ring | wheel, and lifetime was investigated. The results are shown graphically in FIG. “○” indicates that the main component is PFA, “Δ” indicates that the main component is ETFE, “□” indicates that the main component is PVDF, and “◇” indicates that the main component is PEEK. "Shows the result when the main component is PEN. The life shown in FIG. 3 is a relative value with the life of No. 51 as “1”, as described above.

As can be seen from this figure, the service life of the bearing in a corrosive aqueous solution can be obtained by blending potassium titanate whisker as a fibrous filler in the resin composition constituting the inner ring and the outer ring with a content of 40% by weight or less. Can be lengthened.
Furthermore, an inner ring and an outer ring were produced from a resin composition containing PFA, ETFE, PVDF, PEEK, or PEN as a main component and carbon fiber as a fibrous filler in various ratios. A mixture (ETFE: KTW = 80: 20) of these inner rings and outer rings (same material as the inner ring), rolling elements made of silicon nitride (Si ₃ N ₄ ), ETFE and potassium titanate whiskers (KTW). The same rolling bearing as described above was assembled using the cage produced by the above.

  Using these bearings, a rotation test in the above corrosive aqueous solution (1N sulfuric acid aqueous solution) was performed, and the bearing life was evaluated based on the vibration value by the same method. And the relationship between the content rate of the fibrous filler in the resin composition which comprises an inner ring | wheel and an outer ring | wheel, and lifetime was investigated. The results are shown graphically in FIG. “○” indicates that the main component is PFA, “Δ” indicates that the main component is ETFE, “□” indicates that the main component is PVDF, and “◇” indicates that the main component is PEEK. "Shows the result when the main component is PEN. The life shown in FIG. 4 is a relative value with the life of No. 51 as “1”, as described above.

As can be seen from this figure, the life of the bearing in a corrosive aqueous solution can be extended by blending carbon fiber as a fibrous filler in the resin composition constituting the inner ring and the outer ring at a content of 40% by weight or less. can do.
Furthermore, an inner ring and an outer ring were made of a resin composition comprising PFA, ETFE, PVDF, PEEK, or PEN, potassium titanate whisker, and PTFE powder. The content of potassium titanate whisker in the resin composition was kept constant at 10% by weight, and the content of PTFE powder was changed to various ratios. In addition, the content rate of PFA etc. changes according to the content rate of PTFE powder. For example, if the content of PTFE powder is 10% by weight, the content of PFA and the like in this resin composition is 80% by weight.

A mixture (ETFE: KTW = 80: 20) of these inner rings and outer rings (same material as the inner ring), rolling elements made of silicon nitride (Si ₃ N ₄ ), ETFE and potassium titanate whiskers (KTW). The same rolling bearing as described above was assembled using the cage produced by the above.
Using these bearings, a rotation test in the above corrosive aqueous solution (1N sulfuric acid aqueous solution) was performed, and the bearing life was evaluated based on the vibration value by the same method. And the relationship between the content rate of the solid lubricant in the resin composition which comprises an inner ring | wheel and an outer ring | wheel, and lifetime was investigated. The results are shown graphically in FIG. “○” indicates that the main component is PFA, “Δ” indicates that the main component is ETFE, “□” indicates that the main component is PVDF, and “◇” indicates that the main component is PEEK. "Shows the result when the main component is PEN. The life shown in FIG. 5 is a relative value in which the life of No. 51 is “1” in the same manner as described above.

  As can be seen from this figure, when using a resin composition comprising potassium titanate whiskers with a content of 10% by weight as the resin composition constituting the inner ring and the outer ring, PTFE powder is added to the resin composition. By blending at a content of 40% by weight or less (preferably 10 to 30% by weight), the life of the bearing in the corrosive aqueous solution can be extended. Moreover, when both are mix | blended rather than the case where only a solid lubricant (PTFE powder) and only a fibrous filler (potassium titanate whisker or carbon fiber) are mix | blended from the comparison with FIG. 5 and FIGS. It can be seen that the life can be extended.

  Furthermore, an inner ring and an outer ring were made from a resin composition comprising PFA, ETFE, PVDF, PEEK, or PEN, carbon fiber, and PTFE powder. The carbon fiber content in the resin composition was fixed at 10% by weight, and the PTFE powder content was changed to various ratios. In addition, the content rate of PFA etc. changes according to the content rate of PTFE powder. For example, if the content of PTFE powder is 10% by weight, the content of PFA and the like in this resin composition is 80% by weight.

A mixture (ETFE: KTW = 80: 20) of these inner rings and outer rings (same material as the inner ring), rolling elements made of silicon nitride (Si ₃ N ₄ ), ETFE and potassium titanate whiskers (KTW). The same rolling bearing as described above was assembled using the cage produced by the above.
Using these bearings, a rotation test in the above corrosive aqueous solution (1N sulfuric acid aqueous solution) was performed, and the bearing life was evaluated based on the vibration value by the same method. And the relationship between the content rate of the solid lubricant in the resin composition which comprises an inner ring | wheel and an outer ring | wheel, and lifetime was investigated. The results are shown graphically in FIG. “○” indicates that the main component is PFA, “Δ” indicates that the main component is ETFE, “□” indicates that the main component is PVDF, and “◇” indicates that the main component is PEEK. "Shows the result when the main component is PEN. The life shown in FIG. 6 is a relative value in which the life of No. 51 is “1” in the same manner as described above.

  As can be seen from this figure, when a resin composition comprising carbon fiber in a content of 10% by weight is used as the resin composition constituting the inner ring and the outer ring, 40 wt.% Of PTFE powder is contained in this resin composition. By blending at a content of not more than% (preferably 10 to 30% by weight), the life of the bearing in a corrosive aqueous solution can be extended. 6 and FIG. 2 to FIG. 4 show that when both are blended rather than when only the solid lubricant (PTFE powder) or only the fibrous filler (potassium titanate whisker or carbon fiber) is blended. It can be seen that the life can be extended.

  Furthermore, an inner ring and an outer ring were made from a resin composition comprising PFA, PVDF, PEEK, or PEN, potassium titanate whisker, and PTFE powder. The content of PTFE powder in this resin composition was fixed at 10% by weight, and the content of potassium titanate whiskers was changed to various ratios. In addition, the content rate of PFA etc. changes according to the content rate of PTFE powder. For example, if the content of potassium titanate whiskers is 10% by weight, the content of PFA and the like in this resin composition is 80% by weight.

A mixture (PVDF: KTW = 80: 20) of these inner and outer rings (same material as the inner ring), rolling elements made of silicon nitride (Si ₃ N ₄ ), PVDF and potassium titanate whiskers (KTW) The same rolling bearing as described above was assembled using the cage produced by the above.
Using these bearings, a rotation test in the above corrosive aqueous solution (1N sulfuric acid aqueous solution) was performed, and the bearing life was evaluated based on the vibration value by the same method. And the relationship between the content rate of the solid lubricant in the resin composition which comprises an inner ring | wheel and an outer ring | wheel, and lifetime was investigated. The results are shown graphically in FIG. “◯” indicates the result when the main component is PFA, “□” indicates the result when the main component is PVDF, “◇” indicates the result when the main component is PEEK, and “*” indicates the result when the main component is PEN. . The life shown in FIG. 7 is a relative value in which the life of No. 51 is “1” in the same manner as described above.

  As can be seen from this figure, when a resin composition comprising 10% by weight of PTFE powder is used as the resin composition constituting the inner ring and the outer ring, 40% by weight or less of potassium titanate whisker is contained in this resin composition. By blending at a content of (preferably 10 to 30% by weight), the life of the bearing in the corrosive aqueous solution can be extended. Moreover, when both are mix | blended rather than the case where only solid lubricant (PTFE powder) or a fibrous filler (potassium titanate whisker or carbon fiber) is mix | blended from the comparison with FIG. 7 and FIGS. It can be seen that the life can be extended.

[No. 87 to No. 98]
As rolling bearings for testing, No. 87 to No. 95 were assembled single row deep groove ball bearings (inner diameter 10 mm, outer diameter 26 mm, width 8 mm) corresponding to nominal number 6000. As shown in FIG. 1, this bearing is composed of an outer ring 1, an inner ring 2, a ball (rolling element) 3, and a crown-shaped cage 4, and no seal is provided. Moreover, as the rolling bearings of No. 96 to 98, inner rings, outer rings, and balls having the same shape as the deep groove ball bearing were used, and a full ball bearing without using a cage and having no seal was assembled.

The constituent materials of the inner ring, outer ring, rolling element, and cage of each bearing are shown in Table 5 below. The same material was used for the inner ring and the outer ring for each sample. The inner ring and outer ring of each sample and the cages No. 87 to No. 95 were produced by injection molding. Moreover, what was shown below was used as resin and an additive.
Fluoropolymer that can be melt-molded;
PFA: “Neoflon PFA AP-201” manufactured by Daikin Industries
PVDF: “Kureha KF Polymer T- # 1000” manufactured by Kureha Chemical Industry
Or "Kureha KF Polymer T- # 850"
Heat-resistant resin that can be melt-molded;
TPI: Mitsui Toatsu Chemical "Aurum 400"
PEN: “ID300” made by Idemitsu Material
PEEK: "Victorex PEEK 150G" manufactured by Victorex
PEEK-PBI: Hoechst Celanese “Cerasol TU-60”
PPS: "Ryton R-6" manufactured by Philippe Sporium
Liquid crystal polymer;
LCP1 (fully aromatic liquid crystal polymer)
: Sumitomo Chemical "Sumika Super LCP E6000"
LCP2 (semi-aromatic liquid crystal polymer)
: "NOVACCURATE E310" manufactured by Mitsubishi Kasei
Solid lubricants;
PTFE: “Lublon L-5” manufactured by Daikin Industries, Ltd., powder fiber filler having an average particle size of 0.2 μm;
Potassium titanate whisker (abbreviated as “KTW” in Table 5)
: "Tismo D-101" manufactured by Otsuka Chemical,
Average fiber diameter 0.3-0.6 μm, length 10-20 μm
Carbon fiber: “Kureka Chop M-102S” manufactured by Kureha Chemical Industry,
Average fiber diameter 14.5μm, length 0.2mm

  Here, in the case where a resin composition comprising a heat-resistant resin or fluororesin that can be melt-molded (hereinafter referred to as “melt-moldable resin”) and a liquid crystal polymer is used, the resin that can be melt-molded in the resin composition The content of was 70% by weight, and the content of the liquid crystal polymer was 30% by weight. When a resin composition comprising a melt-moldable resin, a liquid crystal polymer, and a fibrous filler or a solid lubricant is used, the content of the melt-moldable resin in the resin composition is 60% by weight, The content was 20% by weight, and the content of the fibrous filler or solid lubricant was 20% by weight.

When using a resin composition comprising a melt moldable resin, a liquid crystal polymer, a fibrous filler, and a solid lubricant, the content of the melt moldable resin in the resin composition is 50% by weight, The content rate was 20% by weight, the content rate of the fibrous filler was 10% by weight, and the content rate of the solid lubricant was 20% by weight.
The resin composition was mixed as follows in order to prevent breakage of the fibrous filler. That is, first, the material excluding the fibrous filler is dry-mixed with a Henschel mixer, and then the mixture is put into a twin screw extruder. The fibrous filler is put into a twin-screw extruder from a fixed side feeder and kneaded with the mixture. This kneaded product is extruded and granulated into pellets. The resin composition pellets or resin single pellets thus obtained were supplied to an injection molding machine, and injection molding was performed under optimal injection conditions for each material.

In the No. 96 rolling bearing, only rolling elements made of ceramics (Si ₃ N ₄ ) are arranged. In the No. 97 rolling bearing, rolling elements formed of ceramics (Si ₃ N ₄ ) and rolling elements formed of PTFE are alternately arranged. In the rolling bearing No. 98, rolling elements made of glass and rolling elements made of hard carbon are alternately arranged.

  Each assembled rolling bearing was subjected to a rotation test in a 1N sulfuric acid aqueous solution using a bearing rotation tester manufactured by NSK Ltd. under the following conditions to evaluate the bearing life based on the vibration value. That is, the radial vibration generated in the bearing was constantly measured during the rotation test, and the test was stopped when the vibration value became three times or more the initial value, and the total number of rotations up to that time was regarded as the life. Note that all the rolling bearings No. 87 to No. 98 were not lubricated with grease.

<Rotational test conditions>
Atmospheric pressure: Atmospheric pressure Atmospheric temperature: Normal temperature Radial load: 49N
Rotation speed: 300rpm
Further, in order to compare the life of each test bearing, a relative value was calculated when the life of No. 51 corresponding to a conventional all-metal rolling bearing was “1”. These results are also shown in Table 5 below.

  As can be seen from this table, the bearings of No. 89 to No. 98 corresponding to the examples of the present invention are more corrosive than the bearings of No. 51 to No. 53 and No. 86 corresponding to the comparative examples. The lifetime in the environment is significantly longer. The bearings No. 87 to No. 98 in which the inner ring and the outer ring are formed of the resin composition to which the liquid crystal polymer is added are more corrosive than No. 86 in which the inner ring and the outer ring are formed only of PEEK. It can be seen that the lifetime at Of the bearings No. 87 to No. 98, the rolling elements are made of ceramics or glass, and the bearings of No. 88 to No. 98 are made more than the bearings of No. 87 whose rolling elements are made of metal. It can be seen that the lifetime in a corrosive environment is prolonged.

Furthermore, an inner ring and an outer ring were produced from a resin composition in which LCP1 was blended at various ratios with PVDF, PEEK, TPI, or PEN. A mixture (PVDF: KTW = 80: 20) of these inner and outer rings (same material as the inner ring), rolling elements made of silicon nitride (Si ₃ N ₄ ), PVDF and potassium titanate whiskers (KTW) The same rolling bearing as described above was assembled using the cage produced by the above.

  Using these bearings, a rotation test in the above corrosive aqueous solution (1N sulfuric acid aqueous solution) was performed, and the bearing life was evaluated based on the vibration value by the same method. And the relationship between the content rate of LCP1 (liquid crystal polymer) in the resin composition which comprises an inner ring | wheel and an outer ring | wheel, and lifetime was investigated. The results are shown graphically in FIG. “□” indicates that the resin composition is composed of PVDF and LCP1, “◇” indicates that the resin composition is composed of PEEK and LCP1, and “+” indicates that the resin composition is composed of TPI and LCP1. "Shows the result when the resin composition is composed of PEN and LCP1. In addition, the lifetime of FIG. 8 is a relative value which made the lifetime of No. 51 "1" similarly to the above.

As can be seen from this figure, by blending LCP1 at a content of 50% by weight or less (preferably 10 to 40% by weight) with the resin composition constituting the inner ring and the outer ring, the bearing of the bearing in a corrosive aqueous solution can be obtained. The lifetime can be extended.
Furthermore, an inner ring and an outer ring were made of a resin composition composed of PVDF, PEEK, TPI, or PEN, LCP1, and PTFE powder. The content of LCP1 in this resin composition was kept constant at 20% by weight, and the PTFE powder was changed to various ratios. In addition, the content rate of PVDF etc. changes according to the content rate of PTFE powder. For example, if the content of PTFE powder is 10% by weight, the content of PVDF and the like in this resin composition is 70% by weight.

A mixture (PVDF: KTW = 80: 20) of these inner and outer rings (same material as the inner ring), rolling elements made of silicon nitride (Si ₃ N ₄ ), PVDF and potassium titanate whiskers (KTW) The same rolling bearing as described above was assembled using the cage produced by the above.
Using these bearings, a rotation test in the above corrosive aqueous solution (1N sulfuric acid aqueous solution) was performed, and the bearing life was evaluated based on the vibration value by the same method. And the relationship between the content rate of PTFE powder (solid lubricant) in the resin composition which comprises an inner ring | wheel and an outer ring | wheel, and lifetime was investigated. The results are shown graphically in FIG. “□” indicates that the main component is PVDF, “◇” indicates that the main component is PEEK, “+” indicates that the main component is TPI, and “*” indicates that the main component is PEN. The results are shown. 9 is a relative value in which the life of No. 51 is “1” in the same manner as described above.

As can be seen from this figure, when using a resin composition comprising LCP1 at a content of 20% by weight as the resin composition constituting the inner ring and the outer ring, 40% by weight of PTFE powder is contained in this resin composition. By blending with the following content (preferably 10 to 30% by weight), the life of the bearing in the corrosive aqueous solution can be extended.
Furthermore, an inner ring and an outer ring were made from a resin composition comprising PVDF, PEEK, TPI, or PEN, LCP1, and potassium titanate whisker. The content of LCP1 in this resin composition was kept constant at 20% by weight, and the content of potassium titanate whiskers was changed to various ratios. In addition, content rates, such as PVDF, change according to the content rate of potassium titanate whisker. For example, if the content of potassium titanate whiskers is 10% by weight, the content of PVDF and the like in this resin composition is 70% by weight.

A mixture (PVDF: KTW = 80: 20) of these inner and outer rings (same material as the inner ring), rolling elements made of silicon nitride (Si ₃ N ₄ ), PVDF and potassium titanate whiskers (KTW) The same rolling bearing as described above was assembled using the cage produced by the above.
Using these bearings, a rotation test in the above corrosive aqueous solution (1N sulfuric acid aqueous solution) was performed, and the bearing life was evaluated based on the vibration value by the same method. And the relationship between the content rate of the potassium titanate whisker (fibrous filler) in the resin composition which comprises an inner ring | wheel and an outer ring | wheel and lifetime was investigated. The results are shown graphically in FIG. “□” indicates that the main component is PVDF, “◇” indicates that the main component is PEEK, “+” indicates that the main component is TPI, and “*” indicates that the main component is PEN. The results are shown. 10 is a relative value in which the life of No. 51 is set to “1” in the same manner as described above.

As can be seen from this figure, when using a resin composition comprising LCP1 at a content of 20% by weight as the resin composition constituting the inner ring and the outer ring, 40 titanic acid whisker whiskers are contained in the resin composition. By blending at a content of not more than wt% (preferably 5 to 30 wt%), the life of the bearing in a corrosive aqueous solution can be extended.
Furthermore, an inner ring and an outer ring were produced from a resin composition comprising PVDF, PEEK, TPI, or PEN, LCP1, potassium titanate whisker, and PTFE powder. The contents of LCP1 and potassium titanate whisker in the resin composition were fixed at 15% by weight, respectively, and the content of PTFE powder was changed to various ratios. In addition, the content rate of PVDF etc. changes according to the content rate of PTFE powder. For example, if the content of PTFE powder is 10% by weight, the content of PVDF and the like in this resin composition is 60% by weight.

A mixture (PVDF: KTW = 80: 20) of these inner and outer rings (same material as the inner ring), rolling elements made of silicon nitride (Si ₃ N ₄ ), PVDF and potassium titanate whiskers (KTW) The same rolling bearing as described above was assembled using the cage produced by the above.
Using these bearings, a rotation test in the above corrosive aqueous solution (1N sulfuric acid aqueous solution) was performed, and the bearing life was evaluated based on the vibration value by the same method. And the relationship between the content rate of PTFE powder (solid lubricant) in the resin composition which comprises an inner ring | wheel and an outer ring | wheel, and lifetime was investigated. The results are shown graphically in FIG. “□” indicates that the main component is PVDF, “◇” indicates that the main component is PEEK, “+” indicates that the main component is TPI, and “*” indicates that the main component is PEN. The results are shown. In addition, the lifetime of FIG. 11 is a relative value which set the lifetime of No. 51 to "1" similarly to the above.

  As can be seen from this figure, when a resin composition comprising LCP1 and potassium titanate whisker each having a content of 15% by weight is used as the resin composition constituting the inner ring and the outer ring, By blending the PTFE powder at a content of 30% by weight or less (preferably 5 to 30% by weight), the life of the bearing in the corrosive aqueous solution can be extended.

1 outer ring 2 inner ring 3 ball (rolling element)
4 Cage

Claims (2)

In a rolling bearing provided with an inner ring, an outer ring, and rolling elements made of a corrosion-resistant material, and a cage made of a resin composition,
At least one of the inner and outer rings, and P VDF Ru fluororesin der capable melt molding, composed of a fibrous filler is carbon fibers or potassium titanate whisker, synthetic resin component consists only PVDF, said fibers Formed by a resin composition having a content of a filler of 5% by weight or more and 40% by weight or less ,
The raceways of the inner and outer rings are finished by machining,
A rolling bearing, wherein the cage is made of a resin composition mainly composed of a fluororesin that can be melt-molded. The rolling elements are SUS440C, LNS125, ES1, SUS630, silicon nitride (Si ₃ N ₄ ), silicon carbide (SiC), sialon, partially stabilized zirconia (ZrO ₂ ), hard carbon, and alumina (Al ₂ O ₃₎ according to claim 1 Symbol mounting of the rolling bearing consists of either.

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