JP2008215419A - Rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing capable of preventing leakage of a lubricant or remaining of the lubricant in a lower part of a sealing member even in an environment wherein vibration is generated or under a high speed rotation condition, and capable of maintaining lubricating performance for a long time in a rolling bearing equipped with the sealing member without a weir. <P>SOLUTION: The rolling bearing 1 is provided with an inner ring 2, an outer ring 3, a plurality of rolling elements 4 arranged between the inner and the outer rings, a retainer 5 retaining the rolling elements 4, and the sealing member 6 protruding from both end surfaces of the inner ring 2 and the outer ring 3 in a U-shaped cross sectional shape and sealing the bearing both end parts, and a porous solid lubricant 7 is enclosed in an inner space of the sealing member 6, which essentially contains a lubricant ingredient and a resin ingredient and is a solid matter having porosity imparted thereto by foaming and curing the resin ingredient. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rolling bearing, and more particularly to a bearing for a main motor used in a railway vehicle and having an insulating layer on a raceway.

  Conventionally, a bearing without a seal is used as a bearing for a main motor used in a railway vehicle, and has a structure having grease pockets on both sides of the bearing. In this structure, since there is a distance between the lubricant such as grease and the bearing, troubles due to poor lubrication often occur. Therefore, in order to reduce the distance between the lubricant and the bearing, an insulating bearing with a hermetic seal (sealing member) that also serves as a grease pocket has been developed (see Patent Document 1). However, in such an insulated bearing with a hermetic seal, the grease in the hermetic seal is reduced if the grease leaks from the seal or the viscosity of the grease decreases due to a rise in temperature during rotation of the bearing. There is a problem that is biased to the bottom of the seal.

  As a countermeasure to this problem, a structure in which a weir is provided in a hermetic seal is known (see Patent Document 2). As shown in FIG. 4, the cylindrical roller bearing 11 described in Patent Document 2 includes an inner ring 12, an outer ring 13, a cylindrical roller 14 disposed between the inner ring 12 and the outer ring 13, and a distance between the cylindrical rollers 14. And the sealing seal 16 projecting from both end faces of the inner ring 12 and the outer ring 13, and the outer diameter face and both end faces of the outer ring 13 are covered with an insulating material 13a. In order to keep the grease in the hermetic seal 16 evenly, the inside of the hermetic seal is divided into a plurality of divided regions by a weir 17 protruding from the inner wall surface of the hermetic seal 16. This can prevent the grease from being biased to the lower part of the seal.

However, since the above-mentioned hermetic seal has a plurality of independent divided regions, it is necessary to provide grease inlets for each divided region to enclose the grease, and there is a problem that the number of work steps required for enclosing the grease increases significantly. is there. In addition, the use of the weir complicates the structure of the hermetic seal, which increases the cost of molding the seal. Further, if the grease in the hermetic seal excessively flows into the bearing due to vibration during operation or the like, the agitation resistance increases, which may cause a rapid temperature increase.
JP 2003-13971 A JP 2004-346972 A

  The present invention has been made in order to cope with such problems, and in a rolling bearing having a sealing member without a weir, leakage of a lubricant and sealing member even under an environment where vibration occurs and under high speed rotation conditions. It is an object of the present invention to provide a rolling bearing in which the lubricant does not stay in the lower part of the shaft and the lubricating performance can be maintained for a long time.

The rolling bearing of the present invention includes an inner ring, an outer ring, a plurality of rolling elements disposed between the inner and outer rings, a cage that holds the rolling elements, and a U-shape from both end faces of the inner ring and the outer ring. A rolling bearing provided with a sealing member that protrudes in a cross-sectional shape and seals both ends of the bearing, wherein the lubricating component and the resin component are essential components in the internal space of the sealing member, and the resin component is foamed and cured. Then, a porous solid lubricant, which is a porous solid, is enclosed.
The porous solid lubricant is sealed in a portion of the internal space of the sealing member that does not contact the end face of the cage, and grease is sealed in a bearing internal space surrounded by the porous solid lubricant. It is characterized by that.

  The porous solid lubricant is characterized by comprising a resin component made of a resin having rubber elasticity or rubber and having a leaching property of the lubricant component due to deformation by an external force. In particular, the resin component is a polyurethane resin.

An insulating layer is provided on an inner diameter surface and an end surface of the inner ring or an outer diameter surface and an end surface of the outer ring.
Further, the rolling bearing is a bearing for a main motor of a railway vehicle.

  The rolling bearing of the present invention encloses the porous solid lubricant in the internal space of the sealing member, so there is no need to provide a weir in the internal space, the structure of the sealing member is simplified, and the molding cost is reduced. Furthermore, since the porous solid lubricant can be sealed at once without dividing the entire internal space of the sealing member, there is no need for circumferential positioning, and workability when incorporating the bearing is improved.

  In addition, the porous solid lubricant is sealed in a portion of the internal space of the sealing member that does not contact the end face of the cage, and grease is sealed in the bearing internal space surrounded by the porous solid lubricant. Can be prevented from moving out of the bearing internal space, and also serves as a supply source of grease base oil. As a result, the lubricating performance can be maintained over a long period of time. Furthermore, the torque can be reduced as compared with the case where the porous solid lubricant is also enclosed around the cage and the rolling elements.

  The porous solid lubricant sealed in the internal space of the sealing member is a solid material in which the lubricating component and the resin component are essential components, and the resin component is foamed and cured to make it porous, and the lubricating component is expanded and cured. Occluded in the solid component. Since the lubricating component occluded in the pores and in the resin component is normally released gradually, the lubricating component does not leak from the sealing member or excessively flow into the bearing, and the agitation resistance increases rapidly. It becomes possible to prevent a temperature rise. Further, since the lubricating component is occluded in the solid component, it is possible to prevent the lubricating component from being biased downward of the sealing member even when subjected to vibration or when the temperature rises during rotation of the bearing. In the present invention, “occlusion” means that a liquid / semi-solid lubricating component does not react with other compounding components and is contained in a solid resin without becoming a compound.

  As described above, the rolling bearing of the present invention has a simple structure because it encloses a porous solid lubricant excellent in lubricant holding capacity in the internal space of the sealing member instead of providing a dam inside the sealing member. The cost can be reduced and the lubrication performance can be maintained over a long period of time even under an environment where vibrations occur and under high speed rotation conditions such as when used as a bearing for a main motor of a railway vehicle.

A rolling bearing according to the present invention will be described with reference to the drawings. FIG. 1 is a partial sectional view of a bearing for a main motor of a railway vehicle which is an embodiment of the rolling bearing of the present invention, and FIG. 2 is a sectional view taken along line AA in FIG.
As shown in FIG. 1, the main motor bearing 1 of the present invention holds an inner ring 2, an outer ring 3, a cylindrical roller 4 that is a plurality of rolling elements arranged between the inner and outer rings, and the cylindrical roller 4. And a pair of sealing members 6 provided at both ends of the inner and outer rings. An insulating layer 8 is provided on the outer diameter surface and the end surface of the outer ring 3.

  As shown in FIG. 1, the sealing member 6 has a U-shaped cross-sectional shape protruding from both end faces of the inner ring 2 and the outer ring 3, and a porous solid lubricant 7 is enclosed in the internal space of the sealing member 6. Has been. The sealing member 6 may be manufactured by injection molding a resin material, or a metal cored bar may be covered with an insulating material such as rubber. The resin material and the insulating material can be used without any particular limitation.

  As shown in FIG. 2, the porous solid lubricant 7 can be filled at a time without dividing the whole without providing a weir or other protrusions in the internal space of the sealing member 6. The porous solid lubricant 7 may be sealed at least in the internal space of the sealing member 6 and can also be sealed in the bearing internal space such as around the cylindrical roller 4 as shown in FIG. In addition to enclosing the porous solid lubricant 7 alone, it can be used in combination with grease or lubricating oil. A resin component, a lubricating component, a filling method, and the like constituting the porous solid lubricant 7 will be described later.

  FIG. 3 shows a partial sectional view of a bearing for a main motor of a railway vehicle when a porous solid lubricant and grease are used in combination. In FIG. 3, the porous solid lubricant 7 is enclosed in a portion of the internal space of the sealing member 6 that does not contact the end face of the cage 5, and the bearing interior such as the periphery of the cylindrical roller 4 surrounded by the porous solid lubricant 7. Grease 9 is sealed in the space. In this aspect, the porous solid lubricant 7 can prevent the grease 9 from moving out of the bearing internal space, and can contribute to the lubrication without waste. Further, the porous solid lubricant 7 serves as a supply source of the base oil of the grease 9, and the lubricating performance can be maintained over a long period. Further, by encapsulating the porous solid lubricant 7 in a portion that does not come into contact with the end face of the cage 5, compared with the case where the porous solid lubricant 7 is also enclosed in the bearing internal space and is in contact with the cage 5 or the cylindrical roller 4, the torque is reduced. it can.

The insulating layer 8 may be provided at least on the outer diameter surface and end surface of the outer ring 3 shown in FIGS. 1 and 3 or the inner diameter surface and end surface of the inner ring 2. The insulating layer is formed by spraying an insulating material such as ceramics.
By forming an insulating layer on the outer diameter surface and end surface of the outer ring 3 or the inner diameter surface and end surface of the inner ring 2, and forming the sealing member 6 from a highly insulating resin material, the insulating performance of the bearing 1 as a whole. Can be improved.

  The present invention is not limited to the main motor bearing described in the embodiment, but can be widely applied to various types of main motor bearings used in an environment where vibrations occur. Examples include deep groove ball bearings, angular contact ball bearings, thrust ball bearings, cylindrical roller bearings, needle roller bearings, thrust cylindrical roller bearings, thrust needle roller bearings, tapered roller bearings, thrust tapered roller bearings, self-aligning ball bearings, Examples thereof include a self-aligning roller bearing, a thrust self-aligning roller bearing, and a plain bearing.

  In the rolling bearing of the present invention, since the lubricating component is occluded in the resin of the encapsulated porous solid lubricant, the flexibility of the resin causes the lubricant to ooze out due to, for example, external force applied during rotation of the bearing or capillary action. It can be released gradually from between the resin molecules. At this time, the amount of the lubricating oil or the like that oozes out can be minimized by changing the degree of elastic deformation according to the magnitude of the external force or the like by selecting the resin. Therefore, lubricating oil or the like does not flow into the bearing more than necessary, and it is possible to prevent the lubricating oil or the like from leaking through the gap between the sealing member and the inner and outer rings, and a rapid temperature increase accompanying an increase in stirring resistance.

  Further, in the porous solid lubricant used in the present invention, the resin component has a large surface area due to foaming, and it is possible to temporarily hold excess lubricating oil or the like that has oozed out in the foam bubbles again. The amount of the lubricating oil or the like that oozes out is stable, and the amount of the lubricating oil or the like that is retained is larger than the non-foamed state by occluding the lubricant in the resin and impregnating the bubbles. For this reason, lubricating performance can be maintained over a long period of time.

  Furthermore, this porous solid lubricant requires very little energy when bent compared to a non-foamed material, and can be flexibly deformed while maintaining a high density of lubricating components. Therefore, in the process of solidifying the porous solid lubricant and cooling it, even if the solid lubricant contracts and embraces the rolling elements, it can be easily deformed because the energy required for bending and deformation is small. The problem of increased rotational torque can be prevented.

As the resin component constituting the porous solid lubricant used in the present invention, a resin component having rubber-like elasticity after foaming and curing, and having a leaching property of the lubricant component by deformation is preferable.
Foaming / curing may be in a form in which foaming / curing is performed at the time of resin production, or in a form in which a foaming agent is added to the resin component and foaming / curing is performed in molding. Here, curing means a cross-linking reaction and / or a phenomenon in which a liquid is solidified. The rubber-like elasticity means rubber elasticity and means that deformation applied by an external force returns to the original shape by eliminating the external force.

As the resin component, either an elastomer or a plastomer or both of a resin (plastic) or rubber can be used as an alloy or copolymer component.
In the case of rubber, various rubbers such as natural rubber, butadiene rubber, styrene butadiene rubber, chloroprene rubber, butyl rubber, nitrile rubber, ethylene propylene rubber, silicone rubber, urethane elastomer, fluorine rubber, and chlorosulfone rubber can be employed.
In the case of plastics, polyurethane resin, polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, polyacetal resin, polyamide 4,6 resin (PA4,6), polyamide 6,6 resin (PA6,6), polyamide General-purpose plastics and engineering plastics such as 6T resin (PA6T) and polyamide 9T resin (PA9T) can be used.
Without being limited to the above plastics, urethane foams such as soft urethane foam, rigid urethane foam, and semi-rigid urethane foam can also be used.
Among the resin components, a polyurethane resin that is easily foamed and cured to make it porous is preferable.

  The polyurethane resin that can be used in the present invention is a foamed / cured product obtained by a reaction between an isocyanate and a polyol, and is preferably a foamed / cured product of a urethane prepolymer having an isocyanate group (—NCO) in the molecule. This isocyanate group may be blocked by other substituents. The isocyanate group contained in the molecule may be at the end of the molecular chain or may be contained at the end of the side chain branched from the molecular chain. The urethane prepolymer may have a urethane bond in the molecular chain. The curing agent for the urethane prepolymer may be a polyol or a polyamine.

The urethane prepolymer can be obtained by reacting a compound having an active hydrogen group with a polyisocyanate.
Examples of the compound having an active hydrogen group include low molecular polyols, polyether polyols, polyester polyols, and castor oil polyols. These can be used alone or as a mixture of two or more. Examples of the low molecular polyol include divalent ones such as ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, hydrogenated bisphenol A, etc. (3- to 8-valent ones) For example, glycerin, trimethylolpropane, hexanetriol, pentaerythritol, sorbitol, shoelace and the like.

  Examples of the polyether polyol include alkylene oxide (alkylene oxide having 2 to 4 carbon atoms, for example, ethylene oxide, propylene oxide, butylene oxide) adducts of the above low molecular polyols and ring-opening polymers of alkylene oxides. Includes polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol.

Examples of polyester polyols include polyester polyols, polycaprolactone polyols, and polyether ester polyols. Polyester polyols are carboxylic acids (aliphatic saturated or unsaturated carboxylic acids such as adipic acid, azelaic acid, dodecanoic acid, maleic acid, fumaric acid, itaconic acid, dimerized linoleic acid and / or aromatic carboxylic acids such as phthalic acid. , Isophthalic acid) and a polyol (the above low molecular polyol and / or polyether polyol).
Polycaprolactone polyol is a polymerization initiator for glycols and triols such as ε-caprolactone, α-methyl-ε-caprolactone, ε-methyl-ε-caprolactone, etc. as organometallic compounds, metal chelate compounds, fatty acid metal acylates, etc. Obtained by addition polymerization in the presence of a catalyst. The polyether ester polyol can be obtained by addition reaction of a polyester having a carboxyl group and / or a hydroxyl group at the terminal with an alkylene oxide such as ethylene oxide or propylene oxide. As the castor oil-based polyol, castor oil and castor oil or castor oil fatty acid and the above low molecular polyol, polyether polyol, and polyester polyol are transesterified or esterified polyol.

Polyisocyanates include aromatic diisocyanates, aliphatic or alicyclic and polyisocyanate compounds.
Aromatic diisocyanates include, for example, diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate and mixtures thereof, 1,5-naphthylene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate Is mentioned.
Aliphatic or alicyclic diisocyanates include, for example, 1,6-hexamethylene diisocyanate, 1,12-dodecane diisocyanate, 1,3-cyclobutane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isopropane diisocyanate. 2,4-hexahydrotoluylene diisocyanate, 2,6-hexahydrotoluylene diisocyanate, 1,3-hexahydrophenyl diisocyanate, 1,4-hexahydrophenyl diisocyanate, 2,4′perhydrodiphenylmethane diisocyanate, 4, 4'-perhydrodiphenylmethane diisocyanate is mentioned.
Examples of the polyisocyanate compound include 4,4 ′, 4 ″ -triphenylmethane triisocyanate, 4,6,4′-diphenyl triisocyanate, 2,4,4′-diphenyl ether triisocyanate, and polymethylene polyphenyl polyisocyanate. In addition, those obtained by modifying a part of these isocyanates into biuret, allophanate, carbodiimide, oxazolidone, amide, imide and the like can be mentioned.

Examples of the urethane prepolymer suitable for the present invention include polypolymer ester polyol and prepolymer obtained by addition polymerization of polyisocyanate to polyether polyol, which are known as casting urethane prepolymers.
The polylactone ester polyol is preferably a urethane prepolymer obtained by addition polymerization of a polyisocyanate in the presence of a short-chain polyol to a polylactone ester polyol obtained by ring-opening reaction of caprolactone.
Examples of the polyether polyol include alkylene oxide addition products or ring-opening polymerization products, and urethane prepolymers obtained by addition polymerization of these with polyisocyanates are preferable.

  If the commercial item of the urethane prepolymer which can be used conveniently for this invention is illustrated, the brand name Plaxel EP by Daicel Chemical Industries may be mentioned. Plaxel EP is a white solid urethane prepolymer having a melting point above room temperature. As an example of polyether polyol, trade name Preminol manufactured by Asahi Glass Co., Ltd. may be mentioned. Preminol is a polyether polyol having a molecular weight of 5000-12000.

  Curing agents for curing the urethane prepolymer and the like include 3,3′-dichloro-4,4′-diaminodiphenylmethane (hereinafter referred to as MOCA) and 4,4′-diamino-3,3′-diethyl-5. , 5'-dimethyldiphenylmethane, trimethylene-bis- (4-aminobenzoate), bis (methylthio) -2,4-toluenediamine, bis (methylthio) -2,6-toluenediamine, methylthiotoluenediamine, 3,5 -Diethyltoluene-2,4-diamine, aromatic polyamines typified by 3,5-diethyltoluene-2,6-diamine, the above polyisocyanates, low molecules typified by 1,4-butaneglycol and trimethylolpropane Polyol, polyether polyol, castor oil-based polyol, polyester-based polyol, hydroxyl-terminated liquid polybutadiene Hydroxyl-terminated liquid polyisoprene, hydroxyl-terminated polyolefin-based polyols and liquid rubbers having two or more hydroxyl groups represented by compounds in which the terminal hydroxyl groups of these compounds are modified with isocyanate groups or epoxy groups, etc. are used alone or in combination. Can be used. Of these, aromatic polyamines are preferred for curing urethane prepolymers obtained by addition polymerization of polylactone ester polyols and polyisocyanates because of their superiority in cost and physical properties.

  As a means for foaming the resin component, a well-known foaming means may be employed. For example, a chemical foaming method that generates a volatile gas by a chemical reaction, an organic solvent having a relatively low boiling point such as water, acetone, hexane, or the like. Heat treatment such as physical methods for heating and vaporization, mechanical foaming method in which an inert gas such as nitrogen or air is blown from the outside, azobisisobutyronitrile (AIBN), azodicarbonamide (ADCA), etc. Examples include a method of using a decomposable foaming agent that is chemically decomposed by light irradiation to generate nitrogen gas or the like.

  Since the urethane prepolymer used in the present invention has an isocyanate group in the molecule, it is preferable to use a chemical foaming method using carbon dioxide generated by a chemical reaction between the isocyanate group and the water molecule using water as a foaming agent. This method is preferable because open cells are easily generated.

Moreover, when using the chemical foaming method with such a reaction, it is preferable to use a catalyst as needed, for example, a tertiary amine catalyst or an organometallic catalyst is used. Examples of the tertiary amine catalyst include monoamines, diamines, triamines, cyclic amines, alcohol amines, ether amines, imidazole derivatives, and acid block amine catalysts.
Examples of organometallic catalysts include stanaoctate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin mercaptide, dibutyltin thiocarboxylate, dibutyltin maleate, dioctyltin dimercaptide, dioctyltin thiocarboxylate, octenoate, etc. Is mentioned. Moreover, you may mix and use these multiple types for the purpose of adjusting the balance of reaction.

  Without being limited to the above resin components, various adhesives such as urethane adhesives, cyanoacrylate adhesives, epoxy adhesives, polyvinyl acetate adhesives, polyimide adhesives can be used by foaming and curing. .

  In the present invention, various additives can be used in the resin component as necessary. Additives include antioxidants typified by hindered phenols, reinforcing agents (carbon black, white carbon, colloidal silica, etc.), inorganic fillers (calcium carbonate, barium sulfate, talc, clay, meteorite powder, etc.) Examples include anti-aging agents, flame retardants, metal deactivators, antistatic agents, antifungal agents, fillers, and coloring agents.

The lubricating component that can be used in the present invention can be used regardless of the type as long as it does not dissolve the solid component forming the foam. As the lubricating component, for example, lubricating oil, grease, wax and the like can be used alone or in combination.
Examples of the lubricating oil include paraffinic and naphthenic mineral oils, ester synthetic oils, ether synthetic oils, hydrocarbon synthetic oils, GTL base oils, fluorine oils, and silicone oils. These can be used alone or as a mixed oil.
If the resin material and lubricating oil do not dissolve or disperse due to chemical compatibility such as polarity, using a lubricating oil with close viscosity makes it easier to physically mix and prevent segregation of the lubricating oil. It becomes.

  The grease is obtained by adding a thickener to a base oil, and examples of the base oil include the above-described lubricating oil. Thickeners include, but are not limited to, soaps such as lithium soap, lithium complex soap, calcium soap, calcium complex soap, aluminum soap, aluminum complex soap, and urea-based compounds such as diurea compounds and polyurea compounds. It is not a thing.

The diurea compound is obtained, for example, by reaction of diisocyanate and monoamine. Diisocyanates include phenylene diisocyanate, diphenyl diisocyanate, phenyl diisocyanate, diphenylmethane diisocyanate, octadecane diisocyanate, decane diisocyanate, hexane diisocyanate, and monoamines include octylamine, dodecylamine, hexadecylamine, octadecylamine, oleylamine, aniline, Examples include p-toluidine, cyclohexylamine and the like.
The polyurea compound can be obtained, for example, by reacting diisocyanate with a monoamine or diamine. Examples of the diisocyanate and monoamine include those used for the production of diurea compounds. Examples of the diamine include ethylenediamine, propanediamine, butanediamine, hexanediamine, octanediamine, phenylenediamine, tolylenediamine, xylenediamine, and the like. Is mentioned.

  Examples of waxes include hydrocarbon synthetic waxes, polyethylene waxes, fatty acid ester waxes, fatty acid amide waxes, ketones / amines, hydrogenated oils, and the like. Oils may be mixed with these waxes, and the same oil components as those described above can be used as the oil component to be used.

  Lubricating components further include solid lubricants such as molybdenum disulfide and graphite, friction modifiers such as organic molybdenum, oily agents such as amines, fatty acids and oils, antioxidants such as amines and phenols, petroleum sulfonates, Rust inhibitors such as dinonyl naphthalene sulfonate, sorbitan ester, extreme pressure agents such as sulfur and sulfur-phosphorus, antiwear agents such as organic zinc and phosphorus, metal deactivators such as benzotriazole and sodium nitrite Various additives such as viscosity index improvers such as polymethacrylate and polystyrene may be included.

  The blending ratio of the base oil in the grease is 1 to 98% by weight, preferably 5 to 95% by weight, based on the whole grease component. If the base oil is less than 1% by weight, it will be difficult to sufficiently supply the lubricating oil to the necessary locations. On the other hand, when it is more than 98% by weight, it does not solidify even at low temperatures and remains liquid.

The porous solid lubricant used in the present invention is obtained by foaming and curing a mixture in which a lubricating component and a resin component are essential components, and a curing agent or a foaming agent is blended therewith.
The blending ratio of the lubricating component is 1 to 90% by weight, preferably 5 to 80% by weight, based on the entire mixture. If the lubrication component is less than 1% by weight, the supply amount of the lubrication component is small and a sufficient life cannot be obtained, or the friction coefficient increases due to lack of lubricant, which causes wear. When it exceeds 90% by weight, it does not solidify.
The blending ratio of the resin is 8 to 98% by weight, preferably 20 to 80% by weight, based on the entire mixture. When it is less than 8% by weight, it does not solidify, and when it is more than 98% by weight, the supply amount of the lubricating component is small and a sufficient life cannot be obtained.

  The blending ratio of the curing agent is determined depending on the blending ratio of the resin and the foaming ratio, and the blending ratio of the foaming agent is determined in relation to the foaming ratio described later.

The method of mixing the mixture is not particularly limited, and for example, the mixture can be mixed using a generally used stirrer such as a Henschel mixer, a ribbon mixer, a juicer mixer, a mixing head, or the like.
It is desirable that the above mixture use a surfactant such as a commercially available silicone-based foam stabilizer to uniformly disperse each raw material molecule. Further, the surface tension can be controlled by the type of the foam stabilizer, and the type of the generated bubbles can be controlled to open cells or closed cells. Examples of such surfactants include anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, silicone surfactants, and fluorine surfactants.

The porous solid lubricant used in the present invention has a lubricating component occluded inside the resin, and can supply the lubricating component to the outside by an external force applied during rotation of the bearing or a capillary phenomenon.
In order to occlude the lubricating component inside the resin, it is desirable to employ a reactive impregnation method in which a foaming reaction and a curing reaction are simultaneously performed in the presence of the lubricating component. In this way, it is possible to highly fill the inside of the resin with the lubricant, and thereafter, the post-impregnation step of impregnating and replenishing the lubricant can be omitted.
On the other hand, a foam solid body is molded in advance, and only a post-impregnation method impregnating this with a lubricant does not allow a sufficient amount of liquid lubricant to penetrate into the resin. If the lubricating oil is released in a short time and used for a long time, the lubricating oil may be insufficiently supplied. For this reason, the post-impregnation step is preferably employed as an auxiliary means for the reactive impregnation method.

  In the rolling bearing of the present invention, the porous solid lubricant may be foamed and cured after pouring a mixture containing a lubricating component and a resin component into the sealing member, and after foaming and curing at normal pressure. It can be post-processed into a predetermined shape by cutting, grinding, etc., and incorporated into the sealing member. In the case of the embodiment shown in FIG. 3, after the porous solid lubricant is previously incorporated into the sealing member by the above-described methods, the sealing member is mounted on the bearing.

Since a molding die and a grinding process for obtaining a foamed molded article are not required, the present invention employs a method in which the mixture is poured into the sealing member before foaming / curing and foamed / cured in the sealing member. It is preferable. In the present invention, since no weir or the like is provided inside the sealing member, the mixture can be poured from one place and incorporated. By adopting this method, the manufacturing process is simplified and the cost can be reduced.
In the case of the embodiment shown in FIG. 1, after the sealing member is mounted on the bearing, the mixture can be poured into the sealing member and into the bearing inner space having a complicated shape.

  It is preferable that the bubbles to be generated when foamed by foaming at the time of foaming / curing are open cells that communicate with each other, and the lubricating component can be directly removed from the surface of the resin via the open cells by external stress. This is to supply. In the case of closed cells where the bubbles do not communicate with each other, the entire amount of lubricating oil in the solid component is temporarily isolated in the closed cells, making it difficult to move between the bubbles and supplying them around the rolling elements when necessary. May not be.

  In the present invention, the open cell ratio of the porous solid lubricant is preferably 50% or more, more preferably 70% or more. When the open cell ratio is less than 50%, the ratio of the lubricating oil in the resin component temporarily taken up into the closed cells increases and may not be supplied to the outside when necessary.

  The expansion ratio of the porous solid lubricant used in the present invention is preferably 1.1 to 100 times. More preferably, it is 1.1 to 10 times. This is because when the expansion ratio is less than 1.1 times, the bubble volume is small and deformation is not allowed when external stress is applied, or the porous solid is too hard to deform following external stress. There is. If it exceeds 100 times, it will be difficult to obtain the strength to withstand external stress, which may lead to damage or destruction.

Specific examples of the porous solid lubricant used in the present invention are illustrated below.
[Specific Example 1]
Urethane prepolymer (manufactured by Daicel Chemical Industries: Plaxel EP1130) 55% by weight, silicone foam stabilizer (Toray Industries, Inc .: SRX298) 2% by weight and urea grease (manufactured by Nippon Oil Co., Ltd .: Vironock Universal N6C) 37% by weight And stirred well at 120 ° C. To this was added 4% by weight of an amine curing agent (manufactured by Ihara Chemical Co., Ltd .: Iharacamine MT), and after stirring, 2% by weight of ion-exchanged water as a blowing agent was added to obtain a mixture. This mixture was filled inside the sealing member and allowed to stand for 1 hour in a constant temperature bath set at 120 ° C. for curing to obtain a sealing member enclosing a porous solid lubricant. The sealing member is attached to the bearing.

[Specific Example 2]
Polyether polyol (Asahi Glass Co., Ltd .: Preminol SX4004) 20% by weight, silicone foam stabilizer (Toray Industries, Inc .: SRX298) 0.5% by weight, lubricating oil (Shin Nippon Oil Co., Ltd .: Turbine 100) 70% by weight, amine type A catalyst (Tosoh Corporation: TOYOCAT DB2) 0.5% by weight and 0.5% by weight of water as a blowing agent were added, and the mixture was heated at 90 ° C. and well stirred. To this, 8.5% by weight of isocyanate (manufactured by Nippon Polyurethane Co., Ltd .: Coronate T80) was added and stirred well to obtain a mixture. This mixture was filled inside the sealing member and allowed to stand for 1 hour in a constant temperature bath set at 120 ° C. for curing to obtain a sealing member enclosing a porous solid lubricant. The sealing member is attached to the bearing.

  The rolling bearing of the present invention encloses a porous solid lubricant excellent in lubricant retention in the internal space of the sealing member, so that it can be used stably for a long time even in an environment where vibrations occur, and is produced at low cost. it can. For this reason, it can utilize suitably as a bearing for main motors used for a rail vehicle.

It is a partial cross section figure of the bearing for main motors of the railway vehicle which is one Example of the rolling bearing of this invention. It is the sectional view on the AA line in FIG. It is a partial cross section figure of the bearing for main motors of the railway vehicle which is another Example of the rolling bearing of this invention. It is a partial cross section figure of the conventional main motor bearing.

Explanation of symbols

1,11 Rolling bearing (cylindrical roller bearing)
2,12 Inner ring 3,13 Outer ring 4,14 Rolling element (cylindrical roller)
5, 15 Cage 6, 16 Sealing member (sealing seal)
7 Porous solid lubricant 8 Insulating layer 9 Grease

Claims (6)

An inner ring, an outer ring, a plurality of rolling elements disposed between the inner and outer rings, a cage that holds the rolling elements, and a U-shaped cross-sectional shape projecting from both end faces of the inner ring and the outer ring, and bearings A rolling bearing comprising a sealing member for sealing both ends,
A rolling bearing characterized in that an internal space of the sealing member contains a lubricating solid component and a resin component as essential components, and a porous solid lubricant, which is a solid material obtained by foaming and curing the resin component, is made porous. .   The porous solid lubricant is enclosed in a portion of the internal space of the sealing member that does not contact the end face of the cage, and grease is enclosed in a bearing internal space surrounded by the porous solid lubricant. The rolling bearing according to claim 1, wherein   The rolling bearing according to claim 1, wherein an insulating layer is provided on an inner diameter surface and an end surface of the inner ring or an outer diameter surface and an end surface of the outer ring.   The porous solid lubricant comprises a resin component made of a rubber-like elastic resin or rubber, and has a leaching property of the lubricating component due to deformation by an external force. 3. A rolling bearing according to 3.   The rolling bearing according to any one of claims 1 to 4, wherein the resin component is a polyurethane resin.   The rolling bearing according to any one of claims 1 to 5, wherein the rolling bearing is a bearing for a main motor of a railway vehicle.

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