JP5346566B2 - Porous solid lubricant encapsulated bearing and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a porous solid lubricant enclosed bearing which is excellent in lubricity of a solid lubricant holding lubricating oil, has long life, and can be rotated at high speed, and which makes it possible to relatively simplify the production steps, thereby meeting the requirement of cost reduction. <P>SOLUTION: The porous solid lubricant enclosed bearing has a porous solid lubricant 37 enclosed in a bearing 31. The porous solid lubricant 37 includes a lubricating component and a resin component as essential components, wherein the foaming reaction and the curing reaction of the resin component are simultaneously carried out in the presence of the lubricating component to form the porous solid having the lubricating component occluded at least in the closed pores in the resin. The porous solid lubricant is provided with the resin component composed of resin or rubber having rubber elasticity, and has properties to exude lubricant component by deformation due to external force. The resin component is polyurethane resin. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a porous solid lubricant-enclosed bearing in which a porous solid lubricant is encapsulated.

  Generally, a lubricant is used in a sliding part and a rotating part of most machines represented by automobiles and industrial machines. Normally, rolling bearings are filled with grease to lubricate the friction surfaces between the rolling elements, bearing inner and outer rings and cage, so that the filled grease does not flow out to the outside. A sealing device such as a seal is provided so that dust and moisture do not enter. However, even for rolling bearings with a sealing device, it is difficult to completely seal the grease, and when it is used for a long time, the grease gradually flows out or the grease gradually deteriorates due to moisture entering from the outside into the bearing. Sometimes. In order to solve the problems related to grease sealing failure and deterioration prevention, grease with increased lubricating oil and shape retention and liquid lubricant can be retained to prevent scattering and dripping. Solid lubricants are also known.

For example, there is a solid lubricant in which ultra-high molecular weight polyolefin or urethane resin and its curing agent are mixed with lubricating oil and grease, and a liquid lubricant component is held between the resin molecules to gradually exude physical properties. It is known (see Patent Documents 1 to 3).
Also known is a self-lubricating polyurethane elastomer obtained by reacting a polyol, which is a polyurethane raw material, with a diisocyanate in a lubricating component in the presence of a lubricant (see Patent Document 4).
In addition, an oil-containing foam is known in which a solid component, which is a resin component, is made into a foam, and this is post-impregnated with a lubricating oil, and provided in the vicinity of a friction contact portion inside the bearing (see Patent Document 5).

  These solid lubricants, when sealed in a bearing and solidified, gradually exude the lubricating oil, which eliminates the need for maintenance to replenish the lubricating oil. It is intended to be useful for extending the life of bearings in environments and environments where strong inertial forces are applied.

However, in the rolling bearing filled with the solid lubricant according to the above-mentioned prior art, it is used because the resin component which is a base material melts due to short life, easy to seize at high speed rotation, and large heat generation. There is a disadvantage that it can not. In the full pack specification, the solid lubricant contracts in the process of cooling after solidifying the solid lubricant in the bearing, and the lubricant itself entraps the rolling elements, resulting in an increase in rotational torque. There is a problem that it is easy to generate heat.
In addition, in the process of manufacturing such a solid lubricant, many manufacturing processes are required for reliably impregnating the lubricant and grease, and it is difficult to meet the demand for cost reduction.
JP-A-6-41569 JP-A-6-172770 JP 2000-319681 A JP-A-11-286601 Japanese Patent Laid-Open No. 9-42297

  The present invention has been made in order to address such problems, and is excellent in the lubrication performance of a solid lubricant that holds lubricating oil, can be operated even at high speed rotation with a long service life, and the manufacturing process can be reduced. An object of the present invention is to provide a porous solid lubricant-enclosed bearing that can be made relatively simple and can meet the demand for cost reduction.

The method of manufacturing the porous solid lubricant enclosed bearing of the present invention is a porous solid lubricant manufacturing method of enclosed bearing porous solid lubricant in the bearing is sealed, the porous solid lubricant, After filling the bearing internal space with a mixture containing a resin component having rubbery elasticity after foaming and curing, a lubricating component, a curing agent, a foaming agent, and a foam stabilizer, the lubricating component is contained in the bearing internal space. The resin component is obtained by being foamed and cured to be porous in the presence of, so that the resin component is sealed in the bearing .
The resin component is a urethane prepolymer having an isocyanate group in the molecule, and the curing agent is an aromatic polyamine. Further, the foaming agent is water. Further, the foam stabilizer is a silicone foam stabilizer.
Further, it characterized in that the lubricating component comprises grease. Further, the grease is a grease using a urea compound as a thickener.

  The porous solid lubricant has an open cell ratio of 50% or more.

The porous solid lubricant encapsulated bearing of the present invention is manufactured by the above manufacturing method. The porous solid lubricant-enclosed bearing is a rolling bearing.

The porous solid lubricant encapsulated bearing of the present invention encloses the porous solid lubricant inside the bearing (the space between the cage and the inner / outer ring, the space between the inner and outer rings in a rolling bearing without the cage, etc.). I use it. This porous solid lubricant has a lubricating component and a resin component as essential components, and is a solid material that is made porous by foaming and curing the resin component in the presence of the lubricating component, and the inside of the resin in which the lubricating component is foamed and cured And is taken in not only in open cells but also in closed cells. For this reason, the porous solid lubricant-enclosed bearing of the present invention has a higher retention amount of the lubricating component in the porous solid lubricant than the retention amount due to impregnation in the continuous pores. Since the lubricating oil is gradually released from the agent around the rolling elements, it can be operated even at a high speed and can contribute to a long life. 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, by enclosing the porous solid lubricant, the lubricant can be present near the rolling surface, and the lubricant is more easily supplied to the rolling surface than grease lubrication. It also serves as a seal member against the entry of dust and moisture from the outside. In addition, since it has many porous portions, it is advantageous in terms of reducing the weight of the bearing.
In addition, since it is not necessary to enclose a lubricant after assembly, production efficiency is improved and manufacturing can be performed at low cost.

The porous solid lubricant encapsulated bearing of the present invention occludes a lubricating component in the resin of the encapsulated porous solid lubricant, and therefore, due to the flexibility of the resin, for example, deformation due to external force such as compression, expansion, bending, torsion, etc. The lubricant can be exuded by capillary action and can be gradually released from between the molecules of the resin. At this time, the amount of lubricating oil that oozes out can be minimized by changing the degree of elastic deformation according to the magnitude of the external force by selecting the resin.
Further, in the porous solid lubricant used in the present invention, the resin component has a large surface area due to foaming, and the excess lubricating oil that has oozed out can be temporarily retained in the foam bubbles again. The amount of lubricating oil to be discharged is stable, and the amount of lubricating oil retained is larger than that in a non-foamed state by occluding the lubricant in the resin and impregnating the bubbles.

In addition, the porous solid lubricant used in the present invention requires very little energy when bent compared to a non-foamed material, and can be flexibly deformed while holding the lubricating oil at a high density. 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. Moreover, since it has many foamed parts, ie, a porous part, it is advantageous also at the point of weight reduction.
In addition, since the porous solid lubricant used in the present invention only foams and cures a mixture containing a lubricating component and a resin component as essential components, no special equipment is required, and it can be filled in any place. It is possible to mold.
Moreover, the density of the porous solid lubricant can be changed by controlling the blending amount of the blending components of the mixture.

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 polyether polyols include alkylene oxide (alkylene oxides having 2 to 4 carbon atoms such as 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. It is done.
Moreover, what modified | denatured some of these isocyanate to biuret, allophanate, carbodiimide, oxazolidone, amide, imide, etc. is 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 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- Aromatic polyamines typified by diethyltoluene-2,4-diamine, 3,5-diethyltoluene-2,6-diamine, the above polyisocyanates, low molecular polyols typified by 1,4-butaneglycol and trimethylolpropane , 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 an isocyanate group or an epoxy group are used alone or in combination. be able to. 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 thereof 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 similar to those used for the production of the diurea compound. Examples of the diamine include ethylenediamine, propanediamine, butanediamine, hexanediamine, octanediamine, phenylenediamine, tolylenediamine, and xylenediamine. 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 and sorbitan esters, 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 lubricating oil (base oil in the case of grease) is 1% to 98% by weight, preferably 5% to 95% by weight of the lubricating oil based on the entire lubricating component. If the lubricating 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, if it is more than 98% by weight, it may remain in a liquid state without being solidified with grease, etc. even at low temperatures, and may not perform the functions specific to solid lubricants.

The blending ratio of the lubricating component to the whole porous solid lubricant (weight) is 1 to 90% by weight, preferably 5 to 80% by weight. 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 urethane prepolymer having an isocyanate group in the molecule 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 lubricating oil to the outside by an external force such as compression, bending, centrifugal force, and expansion of bubbles accompanying a 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 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.

  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. There may be cases where the surrounding area is not sufficiently supplied.

  The open cell ratio of the porous solid lubricant of the present invention 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 open cell ratio of the porous solid lubricant of the present invention can be calculated by the following procedure.
(1) The foam solidified porous solid lubricant is cut into an appropriate size to obtain sample A. The weight of sample A is measured.
(2) Soxhlet A is washed for 3 hours (solvent: petroleum benzine). Thereafter, the sample is left in a thermostatic bath at 80 ° C. for 2 hours to completely dry the organic solvent, and sample B is obtained. The weight of sample B is measured.
(3) The open cell ratio is calculated by the following procedure.
Open cell ratio = (1− (weight of resin component of sample B−weight of resin component of sample A) / weight of lubricating component of sample A) × 100
The resin component weight and the lubrication component weight of Samples A and B are calculated by multiplying the weights of Samples A and B by the composition charge ratio.
Lubricating components taken into discontinuous closed cells are not released to the outside by Soxhlet cleaning for 3 hours, so the weight of sample B is not reduced. The open cell ratio can be calculated as the release of the lubricating component.

  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 times 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.

Porous solid lubricants may be foamed and cured after pouring a mixture containing a lubricating component and a resin component into the bearings into the bearing, and after being foamed and cured at normal pressure, It can be post-processed into a shape and incorporated into the bearing.
It is possible to easily fill any part in a bearing having a complicated shape, and there is no need for a molding die or a grinding process for obtaining a foamed molded product. -It is preferable to adopt a method of pouring into the bearing before curing and foaming and curing in the bearing. By adopting this method, the manufacturing process is simplified and the cost can be reduced.

  These porous solid lubricants can be encapsulated in various known types of bearings. 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. Further, these bearings can be applied regardless of the presence or absence of a seal member or a shield plate.

An example of the porous solid lubricant sealed bearing of the present invention will be described with reference to FIG. FIG. 5 is a sectional view of a deep groove ball bearing according to an embodiment of the present invention.
As shown in FIG. 5, the bearing 31 holds an inner ring 32, an outer ring 33 disposed concentrically with the inner ring 32, a plurality of rolling elements 34 interposed between the inner and outer rings, and the plurality of rolling elements 34. And a seal member 35 fixed to the outer ring 33 and the like. The porous solid lubricant 37 is sealed at least around the rolling element 34.

An example of a method for enclosing the porous solid lubricant in the bearing will be described with reference to FIGS.
FIG. 1 is a schematic view showing an example of sealing in a radial ball bearing (without a seal member) according to another embodiment of the present invention. As shown in FIG. 1, a bearing 1 having an inner ring 2, an outer ring 3, and rolling elements 4 interposed between the inner and outer rings is placed on an iron plate 5 larger than the bearing outer diameter 7 or a jig similar thereto. A well-stirred porous solid lubricant component mixture 6 immediately before foaming is poured into a space surrounded by the inner ring 2, the outer ring 3, and the iron plate 5, and foamed and cured. In this case, after pouring the mixture 6 into the bearing 1, an iron plate 5 larger than the bearing outer diameter 7 or a similar jig may be covered on the bearing 1. When the steel plate or jig is covered, the filling rate of the porous solid lubricant in the bearing is improved. After the foaming / curing of the mixture 6 is completed, the iron plate 5 or a similar jig is removed to obtain a porous solid lubricant sealed bearing.

  FIG. 2 is a schematic view showing an example of sealing in a radial ball bearing (with a seal member) according to another embodiment of the present invention. As shown in FIG. 2, the bearing 11 having the inner ring 12, the outer ring 13, the rolling elements 14 interposed between the inner and outer rings, and the seal member 15 mounted only on one side is arranged with the seal member 15 on the lower side. Leave still. Then, the well-mixed porous solid lubricant component mixture 16 immediately before foaming is poured into the bearing 11 and foamed and cured. In this case, in order to improve the filling rate of the porous solid lubricant in the bearing as in FIG. 1, after the mixture 16 is poured into the bearing 11, an iron plate larger than the outer diameter of the bearing or the like is further formed on the bearing 11. You may put a jig to do. The upper seal member may be attached during the foaming process instead of a jig for improving the filling rate, or may be attached to the bearing 11 after foaming / curing is completed.

FIG. 3 is a schematic view showing an example of encapsulation in a thrust ball bearing according to another embodiment of the present invention. FIG. 4 is a schematic diagram showing the use of the cylindrical jig in FIG. As shown in FIGS. 3 and 4, a mold 25 in which a thrust ball bearing 21 is accommodated is prepared, and a bearing 21 having an inner ring 22, an outer ring 23, and rolling elements 24 interposed between the inner and outer rings is installed. A well-stirred porous solid lubricant component mixture 26 just before foaming is poured into the bearing 21 from the inner diameter side of the bearing 21, and a cylindrical jig 27 having the same diameter as the inner diameter is inserted into the inner diameter portion to be foamed and cured. After the mixture 26 is foamed and cured to become a porous solid lubricant 28, the mold 25 and the cylindrical jig 27 are removed to obtain a porous solid lubricant-enclosed bearing.
An injection molding machine or the like can also be used to enclose the lubricant in the bearing. In this case, the bearing is mounted on a mold, and the porous solid lubricant component mixed in the screw is sealed into the bearing through the nozzle.

  In the porous solid lubricant encapsulated bearing of the present invention, the lubricating component contained in the impregnated state in the porous solid lubrication does not exude suddenly even when the foam is deformed by an external force, and the lubricating component is efficiently removed. It can be used by oozing out on the sliding surface. As a result, the bearing requires a minimum amount of lubrication component, has a long life, and can be operated even at high speed.

Example 1 to Example 2
Silicone foam stabilizers and urea grease were added to the urethane prepolymer as resin components at the blending ratio shown in Table 1, and the mixture was well stirred at 120 ° C. An amine-based curing agent is added to this, and after stirring, water as a foaming agent is added, and the interior space of the ball bearing 6204 is filled, and then left to stand in a thermostatic bath set at 120 ° C. for 1 hour to be cured. A test piece of a solid lubricant sealed bearing was obtained. About the obtained test piece, the bearing endurance test shown below was implemented and the bearing life time was measured. The results are also shown in Table 1. Further, the open cell ratio of the porous solid lubricant was measured based on the above-described method for calculating the open cell ratio. These results are also shown in Table 1.

<Bearing endurance test>
When a radial load of 67 N and a thrust load of 67 N were applied to the obtained specimen and rotated at 10000 rpm at 100 ° C, the input current of the motor driving the rotating shaft exceeded the limit current (the rotational torque was The lifetime was measured until it exceeded twice the starting torque.

Example 3 to Example 4
In the blending ratio shown in Table 1, a silicone foam stabilizer, a lubricating oil, an amine catalyst, and water as a foaming agent were added to the polyether polyol as a resin component, and the mixture was heated at 90 ° C. and stirred well. This was added with isocyanate and stirred well, filled in the internal space of the ball bearing 6204, and then left in a thermostatic bath set at 90 ° C. for 15 minutes to obtain a test piece of a porous solid lubricant sealed bearing. About the obtained test piece, the above-mentioned bearing durability test was implemented and the bearing life time was measured. The results are also shown in Table 1.

Comparative Example 1
A test piece of a non-foamed lubricant-enclosed bearing was obtained by the same production method as in Example 1 except that the resin component was not foamed at the blending ratio shown in Table 1. About the obtained test piece, the above-mentioned bearing durability test was implemented and the bearing life time was measured. The results are also shown in Table 1.

Comparative Example 2
Of the blending ratios shown in Table 1, a foam was formed in the internal space of the ball bearing 6204 in the same manner as in Example 2 except for the lubricating oil. The obtained foam was impregnated with lubricating oil to obtain a test piece of a post-impregnation type foamed lubricant-enclosed bearing. About the obtained test piece, the above-mentioned bearing durability test was implemented and the bearing life time was measured. The results are also shown in Table 1.

Comparative Example 3
Among the blending ratios shown in Table 1, a test piece of a porous solid lubricant-enclosed bearing was obtained by the same method as in Example 3 with a composition excluding the silicone foam stabilizer. About the obtained test piece, the above-mentioned bearing durability test was implemented and the bearing life time was measured. The results are also shown in Table 1.

  As shown in Table 1, each example was able to maintain good lubricity even at high speeds and had a long life.

  The porous solid lubricant-enclosed bearing of the present invention is excellent in the lubrication performance of the solid lubricant that holds the lubricating oil, and can be operated even at high speed rotation with a long service life. Therefore, the stranded wire machine, electric equipment, printing machine, automobile It can be suitably used as a porous solid lubricant encapsulated bearing for various industrial machines such as parts, electrical equipment and construction machines.

It is a schematic diagram which shows the example of enclosure to the radial ball bearing (without a sealing member) which concerns on the other Example of this invention. It is a schematic diagram which shows the example of enclosure to the radial ball bearing (with a sealing member) which concerns on the other Example of this invention. It is a schematic diagram which shows the example of enclosure to the thrust ball bearing (no sealing member) which concerns on the other Example of this invention. It is a schematic diagram which shows use of a cylindrical jig | tool in FIG. It is sectional drawing of the deep groove ball bearing which concerns on one Example of this invention.

Explanation of symbols

1, 11 Radial ball bearing 2, 12, 22, 32 Inner ring 3, 13, 23, 33 Outer ring 4, 14, 24, 34 Ball (rolling element)
5 Iron plate 6, 16, 26 Mixture of porous solid lubricant components 7 Bearing outer diameter 15, 35 Seal member 21 Thrust ball bearing 25 Mold 27 Cylindrical jig 28 Porous solid lubricant 31 Deep groove ball bearing 36 Cage 37 Porous Solid lubricant

Claims (8)

A method for producing a porous solid lubricant-enclosed bearing in which a porous solid lubricant is encapsulated in a bearing internal space,
The porous solid lubricant is filled with a mixture containing a resin component having rubber-like elasticity after foaming and curing, a lubricating component, a curing agent, a foaming agent, and a foam stabilizer, in the bearing internal space, A porous solid lubricant obtained by encapsulating the resin component in the interior space of the bearing in the presence of the lubrication component while foaming and curing the resin component to make it porous. Manufacturing method of encapsulated bearing.   The method for producing a porous solid lubricant-encapsulated bearing according to claim 1, wherein the resin component is a urethane prepolymer having an isocyanate group in the molecule, and the curing agent is an aromatic polyamine.   The method for producing a porous solid lubricant-sealed bearing according to claim 1, wherein the foaming agent is water.   4. The method for producing a porous solid lubricant encapsulated bearing according to claim 1, wherein the lubricating component contains grease.   5. The method for producing a porous solid lubricant encapsulated bearing according to claim 4, wherein the grease is a grease containing a urea compound as a thickener.   The method for producing a porous solid lubricant-enclosed bearing according to any one of claims 1 to 5, wherein the foam stabilizer is a silicone foam stabilizer. A porous solid lubricant encapsulated bearing manufactured by the method for producing a porous solid lubricant encapsulated bearing according to any one of claims 1 to 6 . The porous solid lubricant-enclosed bearing according to claim 7, wherein the porous solid lubricant-enclosed bearing is a rolling bearing.

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