JP2008215418A - Axle bearing for rolling stock - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an axle bearing for a rolling stock with a reduced amount of sealed lubricant, improved sealability, and an elongated maintenance interval of the bearing, and the long lubrication service life. <P>SOLUTION: The axle bearing for the rolling stock is provided with an outer ring 3, an inner ring 2, an inner ring spacer 6, double row tapered rollers 4, a retainer 5, and a sealing device 7 attached to both ends of the outer ring 3. The sealing device 7 is constituted by a seal case 12 and a seal member 11, a porous solid lubricant is enclosed in at least one of a center part space 8b of the outer ring 3, a circumferential space between the double row tapered rollers 4, and an inner space 9b of the sealing device 7, and the porous solid lubricant 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. The porous solid lubricant is fixed to a sliding part of the seal member 11 with a slinger 10 attached to both ends of the inner ring 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a bearing with a sealing device provided with a sealing device, and more particularly to an axle bearing for a railway vehicle.

  Conventionally, in a sealed axle bearing of a railway vehicle, grease has been sealed in a central portion of the outer ring and a double row inner ring assembly portion for lubrication. Most of the grease sealed in the inner ring assembly is usually discharged from the inside of the bearing by rotation and collected in the vicinity of the oil seal. At present, the ratio contributing to the improvement of the lubrication life is very low. For this reason, there will be insufficient lubricant on the sliding surface of the inner ring, which will lead to poor ride comfort due to poor lubrication, shortening the service life due to increased bearing temperature under high-speed operation, and shortening the associated maintenance cycle. There are problems such as not. As a countermeasure, a sealing device or the like having a structure for guiding grease discharged to the bearing end by centrifugal force into the bearing has been developed (see Patent Document 1).

In order to improve the lubrication life compared to Patent Document 1, it is desirable to gradually supply a small amount of oil from the rotating part. However, if grease is only applied to the inner ring, it moves to a site that is unlikely to contribute to extending the lubrication life, such as in the vicinity of the oil seal, at an early stage due to the centrifugal force generated in the rotating part. It is desired that the maintenance cycle of the bearing can be extended by continuing to supply the lubricant to the sliding surface for a long period of time.
Further, the discharged grease plays a role of a wall to prevent excessive grease remaining in the oil seal portion from being discharged, and it is necessary to enclose more grease than necessary for lubrication. In addition, the grease in the center of the outer ring was difficult to move because the outer ring did not rotate, and a large amount of grease was observed during maintenance.
In order to save resources, it was necessary to reduce the amount of grease filled, and a solution was sought.

The role of the sealing device used in railway vehicle axle bearings is to prevent the entry of harmful substances such as dust, moisture, foreign matter, and abrasion powder into the bearing, and the lubricant enclosed in the bearing does not leak outside the bearing. Is to do so.
Sealed axle bearings use rubber lip oil seals to prevent dust and moisture from entering from outside and grease leakage from inside the bearing to ensure sealing performance. In such a case, the rubber lip may be damaged due to long-term use, sealing performance may deteriorate, dust and moisture may be mixed, and grease leakage may occur. Dust / moisture contamination and grease leakage worsen the lubrication situation, resulting in problems such as poor ride comfort, shortening of the service life due to increased bearing temperature under high speed operation, and concomitant shortening of the maintenance cycle.
In addition, if a grease leak occurs, the grease will leak into the route, which may adversely affect the environment. There is a method of improving the sealing performance by increasing the tightness of the seal, but it leads to abnormal heat generation and is difficult to employ.
Japanese Patent Laid-Open No. 2005-172201

  The present invention has been made to cope with such problems, and can reduce the amount of lubricant enclosed, improve the sealing performance, extend the maintenance cycle of the bearing, and has a long lubrication life. An object of the present invention is to provide an industrial axle bearing.

  An axle bearing for a railway vehicle according to the present invention includes an outer ring having a double row track on the inner periphery, a pair of inner rings each having a track on the outer periphery, an inner ring spacer sandwiched between the pair of inner rings in the axial direction, and inner and outer rings. A railcar axle bearing comprising a double-row tapered roller interposed between tracks, a cage for holding the tapered roller at a predetermined interval in the circumferential direction, and a sealing device attached to both ends of the outer ring. A porous solid lubricant is sealed in at least one selected from the central space of the outer ring, the space between the circumferential directions of the double row tapered rollers, and the internal space of the sealing device. The solid lubricant is characterized in that it is a solid material in which a lubricating component and a resin component are essential components, and the resin component is made porous by foaming and curing.

  The sealing device is made of a metal seal case mounted on the inner peripheral surface end of the outer ring, and the outer peripheral surface of the slinger, oil drain, or rear cover that is disposed on both ends of the inner ring. The sealing member is formed by fixing a porous solid lubricant to a sliding contact portion with the slinger, oil drain, or rear lid, and the porous solid lubricant is a lubricating component. In addition, the resin component is an essential component, and the resin component is a solid material which is made porous by foaming and curing.

  The porous solid lubricant is characterized by being foamed and cured using a molding die. Further, the porous solid lubricant is characterized by being foamed and cured in a bearing internal space to be enclosed.

  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.

  The axle bearing for a railway vehicle according to the present invention includes at least one selected from the central space of the outer ring, the space between the circumferential directions of the double-row tapered rollers, and the internal space of the sealing device as an essential component. Since the porous solid lubricant, which is a solid material obtained by foaming and curing the resin component, is enclosed, the inner ring side is lubricated in a sealed axle bearing used for a railway vehicle that is normally used for inner ring rotation. A mechanism for supplying the agent can be realized.

Since the porous solid lubricant used in the railcar axle bearing of the present invention is in the form of a porous solid material, it can store the lubricant, and since it is a solid material, there is no scattering due to rotation. It is possible to improve the lubrication life by supplying a lubricant. Further, since the lubricant is occluded in the porous solid lubricant, for example, the porous solid lubricant is fixed to the inner ring side of the central space of the outer ring, and moves to the outer ring side by the centrifugal force accompanying the rotation of the bearing. The lubricant can be gradually released from the inner ring side around the rolling elements and the bearing sliding portion. Therefore, it is possible to prevent the bearing temperature from increasing at high speed, improve the riding comfort, extend the maintenance cycle such as replenishing grease, and the like.
In addition, the lubricant is not scattered or unevenly distributed in parts that do not contribute to lubrication, and the enclosed lubricant can be used effectively over a long period of time, so it can be reduced by up to about 80% by weight compared to conventional grease alone. This makes it possible to reduce the size and weight of the bearing.

  In the railcar axle bearing of the present invention, the seal member has a double seal structure with the rubber lip by adhering the porous solid lubricant to the sliding contact portion with the slinger, oil drain or rear cover. Moreover, since the porous solid lubricant itself has a lubricating performance, the friction is small and heat generation due to the friction can be prevented. As a result, sealing performance is improved, entry of dust and moisture from the outside, and grease leakage are less likely to occur, and lubrication performance can be maintained well over a long period of time, preventing an increase in bearing temperature under high speed operation. As a result, the ride quality is improved, the service life of lubrication is extended, the maintenance cycle is extended, and maintenance costs are reduced.

  The axle bearing for a railway vehicle of the present invention can incorporate a porous solid lubricant molded using a molding die at the time of manufacturing the bearing, and the incorporated porous solid lubricant occludes a lubricating component. There is no need to enclose a lubricant such as grease after assembling the bearing.

  The railcar axle bearing of the present invention incorporates a porous solid lubricant by foaming and curing in the enclosed bearing internal space, so that it is not necessary to use a molding die, and the enclosed porous solid lubricant Has occluded lubricating components, so that it is not necessary to enclose a lubricant such as grease after assembling the bearing. For this reason, manufacturing costs such as mold production costs and assembly work costs can be reduced.

A railcar axle bearing of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an example of an axle bearing for a railway vehicle according to the present invention. FIG. 2 is a sectional view showing another example of an axle bearing for a railway vehicle according to the present invention. FIG. 3 is an enlarged cross-sectional view of the sealing device according to the present invention.
As shown in FIGS. 1 and 2, this bearing is sandwiched in the axial direction between an outer ring 3 having a double-row raceway on the inner circumference, a pair of inner rings 2 each having a raceway on the outer circumference, and a pair of inner rings 2. An inner ring spacer 6, a double row tapered roller 4 interposed between the raceways of the inner and outer rings 3, a cage 5 that holds the tapered roller 4 at a predetermined interval in the circumferential direction, and attached to both ends of the outer ring 3. And a sealing device 7.

The pair of inner rings 2 are fitted to the ends of axles (not shown) in such a manner that the inner ring spacer 6 is sandwiched from both sides in the axial width direction, and the inner ring 2 has a track 2a on the outer periphery. An annular groove 3 b is formed on the inner peripheral surface of the end portion of the outer ring 3. Double-row tapered rollers 4 are incorporated between the raceway 2a of the inner ring 2 and the raceway 3a of the outer ring 3, and the tapered rollers 4 in each row are held at equal intervals in the circumferential direction by a cage 5.
As shown in FIGS. 1 to 3, the sealing device 7 is disposed in the annular groove 3 b at the end portion of the inner peripheral surface of the outer ring 3, and is disposed in the seal case 12. It is comprised with the sealing member 11 which slidably contacts the outer peripheral surface of the slinger 10 attached to both ends.

A porous solid lubricant is enclosed in at least one selected from the central space of the outer ring 3, the space between the circumferential directions of the double row tapered rollers 4, and the internal space of the sealing device 7. The resin component, the lubricating component, the filling method, and the like constituting the porous solid lubricant will be described later.
The central space of the outer ring 3 may be a space 8a that fills the gap between the inner ring spacer 6 and the outer ring 3 with the width of the inner ring spacer 6 as shown in FIG. The entire space 8 b surrounded by the spacer 6, the inner ring 2, the tapered roller 4, the cage 5 and the outer ring 3 may be used.
As shown in FIG. 1, the internal space of the sealing device 7 is a space 9 a that fills the gap between the slinger 10 and the seal case 12 with a length L between the inner ring side end of the slinger 10 and the inner ring side end of the seal member 11. Alternatively, as shown in FIG. 2, the entire space 9b surrounded by the slinger 10, the seal member 11, the seal case 12, the outer ring 3, the tapered roller 4, the cage 5, and the inner ring 2 may be used.

  Here, the porous solid lubricant encapsulated in each space exudes the lubricant when it slides and is applied to the sliding surface, so that it has excellent wear resistance and low heat generation. As a result, sealing performance can be secured while suppressing sliding heat generation. Due to this low heat generation feature, the temperature rise of the bearing is small, deterioration of the bearing lubricating oil is prevented, and dimensional changes of the inner ring 2 and outer ring 3 (track surface) Deformation). In addition to encapsulating the porous solid lubricant alone, it can be used in combination with grease or lubricating oil.

  As shown in FIG. 3, the porous solid lubricant 11 a is fixed to the sliding contact portion of the seal member 11, that is, the portion that is in sliding contact with the outer peripheral surface of the slinger 10. The resin component, the lubricating component, the fixing method and the like constituting the porous solid lubricant will be described later. In addition, even if the outer peripheral surface of the slinger 10 described above is worn or decentered, the seal member 11 needs to be surely followed. Therefore, the spring 13 is attached to the outer periphery of the sliding contact portion of the seal member 11, The seal member 11 is pressurized to the outer peripheral surface side of the slinger 10 by elastic force.

  Here, the porous solid lubricant fixed to the seal member 11 exudes the lubricant when it slides and is applied to the outer peripheral surface, and therefore has excellent wear resistance and low heat generation. As a result, even if the peripheral speed of the seal member 11 is, for example, 16 m / s or more, the sealing performance can be ensured while suppressing the sliding heat generation. Small and can suppress deterioration of bearing lubricant.

  Nitrile rubber or acrylic rubber is generally used as the material of the seal member 11, but silicone rubber, fluorine rubber, ethylene tetrafluoride (PTFE) resin, or the like is used when the temperature is high. The outer peripheral surface of the slinger 10 that is in sliding contact with the seal member 11 is preferably subjected to heat treatment or hard chrome plating in order to improve wear resistance.

  The railcar axle bearing of the present invention has a lubricating component occluded in the resin of the porous solid lubricant sealed inside or fixed to the seal sliding contact portion. Further, the lubricant can be exuded by thermal expansion due to heat reception or capillary action, and can be gradually released from between the molecules of the resin. 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. Moreover, the density of the porous solid lubricant can be changed by controlling the blending amount of the blending components of the mixture. 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.

  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.

  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, when adopting the method of foaming and curing the porous solid lubricant inside the bearing, it is necessary at the time of bending and deformation even if the solid lubricant shrinks and embraces the tapered roller during cooling after curing. Since the energy is small, it can be easily deformed and 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 and a resin component as essential components, and can supply the lubricant to the bearing sliding portion by an external force such as expansion of bubbles accompanying rotation of the bearing or temperature rise. Is.
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 the impregnation method after impregnating the lubricant alone does not allow a sufficient amount of liquid lubricant to penetrate into the resin. When the lubricant is released in a short time and used for a long time, the lubricant 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 railway vehicle axle bearing of the present invention, the method of enclosing the porous solid lubricant in the central space of the outer ring, the space between the circumferential directions of the tapered rollers and the internal space of the sealing device is as follows: (1) Porous solid lubricant A method of incorporating a molded body obtained by molding an agent into a bearing, and (2) a method of molding a porous solid lubricant in a bearing can be employed without any particular limitation.

The method of obtaining a molded body of a porous solid lubricant to be incorporated into an axle bearing for railway vehicles according to the present invention includes a method using a molding die and a method of cutting into a predetermined shape after foaming and curing under normal pressure. Can be used without restriction.
When using a molding die, there are a single molding method in which a porous solid lubricant is molded alone and an integral molding method in which an inner ring spacer or the like is mounted on the mold.
The single molding method is a method in which a mixture containing a lubricating component and a resin component as essential components is poured into a mold and then foamed and cured.
The integral molding method is a method in which an inner ring spacer or the like is fitted in a mold, a mixture containing a lubricating component and a resin component as essential components is poured into the outer periphery of the inner ring spacer, and then foamed and cured.

  The method for forming the porous solid lubricant in the bearing is, for example, after pouring a mixture containing the lubricating component and the resin component into the central space 8b of the outer ring and the internal space 9b of the sealing device shown in FIG. This is a method of foaming and curing. In this method, the porous solid lubricant is spread over the entire space of the central space 8b of the outer ring, the internal space 9b of the sealing device 7 and the space between the circumferential directions of the double row tapered rollers 4 (not shown) shown in FIG. Can be enclosed. Further, it is not necessary to use a molding die, and the enclosed porous solid lubricant occludes a lubricating component, so that it is not necessary to enclose a lubricant such as grease after assembling the bearing. Therefore, it is possible to reduce the manufacturing cost by eliminating the mold manufacturing cost and the assembly work cost.

The method of fixing the porous solid lubricant to the portion where the sealing member is in sliding contact with the slinger or the like is particularly suitable if the porous solid lubricant fixed to the sliding contact portion of the sealing member is not removed by rotation of the slinger or the like. Can be used without restriction.
For example, a fitting groove is provided in the sliding contact portion of the seal member, and the fixing groove is fixed by foaming and curing in a state where the mixture is filled in the fitting groove. And a method of pasting a porous solid lubricant that has been previously applied and molded. An appropriate adhesive may be selected depending on the resin used and the material of the seal member.

  It is preferable that the bubbles to be generated when being made porous by foaming at the time of foaming / curing are open cells that communicate with each other. This is because the lubricating component occluded in the porous solid lubricant oozes out from the surface of the porous solid lubricant through open cells due to external forces such as the rotation of the bearing and the expansion of the bubbles as the temperature rises. This is because it is supplied directly to 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. May not be supplied.

  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. The mixture was poured into a molding die with an inner ring spacer fitted in the mold and allowed to stand at 120 ° C. for 1 hour to be cured. This inner ring spacer was incorporated to obtain an axle bearing for a railway vehicle.

[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. The mixture was poured into a molding die with an inner ring spacer fitted in the mold and allowed to stand at 120 ° C. for 1 hour to cure. This inner ring spacer was incorporated to obtain an axle bearing for a railway vehicle.

  The railcar axle bearing of the present invention can be realized as a sealed axle bearing used in a railway vehicle because it can realize a mechanism for supplying a lubricant to the inner ring side in a sealed axle bearing used in a railway vehicle used for inner ring rotation. Available to:

It is sectional drawing which shows an example of the axle bearing for railway vehicles of this invention. It is sectional drawing which shows the other example of the axle bearing for rail vehicles of this invention. It is an expanded sectional view of the sealing device in the present invention.

Explanation of symbols

2 inner ring 2a raceway 3 outer ring 3a raceway 3b annular recess 4 roller 5 cage 6 inner ring spacer 7 sealing device 8a, 8b inner space 9a, 9b outer ring inner space 10 slinger 11 seal member 11a porous solid lubricant 12 Seal case 13 Spring

Claims (5)

An outer ring having a double-row track on the inner periphery, a pair of inner rings each having a track on the outer periphery, a double-row tapered roller interposed between the tracks of the inner and outer rings, and the tapered rollers are held at predetermined intervals in the circumferential direction. An axle bearing for a railway vehicle comprising: a cage that includes a sealing device attached to both ends of the outer ring;
A porous solid lubricant is sealed in at least one selected from a central space of the outer ring, a space between circumferential directions of double row tapered rollers, and an internal space of the sealing device, and the porous solid lubricant Is an axle bearing for a railway vehicle characterized in that it is a solid material in which a lubricating component and a resin component are essential components, and the resin component is foamed and cured to be porous. The sealing device is made of a metal seal case attached to the inner peripheral surface end portion of the outer ring, and the outer peripheral surface of the slinger, oil drain, or rear lid disposed on both ends of the inner ring disposed on the seal case. And a sealing member that is in sliding contact with
The seal member is formed by fixing a porous solid lubricant to a sliding contact portion with the slinger, oil drain, or rear lid, and the porous solid lubricant includes a lubricating component and a resin component as essential components, and the resin. 2. The axle bearing for a railway vehicle according to claim 1, wherein the solid bearing is a solid material obtained by foaming and curing a component.   The axle bearing for a railway vehicle according to claim 1 or 2, wherein the porous solid lubricant is foamed and cured using a molding die.   The axle bearing for a railway vehicle according to claim 1, wherein the porous solid lubricant is foamed and hardened in a bearing internal space to be enclosed.   5. The porous solid lubricant according to any one of claims 1 to 4, wherein the porous solid lubricant comprises a resin component having rubber-like elasticity or a resin component made of rubber, and has a leaching property of the lubricant component due to deformation by an external force. A rolling stock axle bearing according to one item.

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