JP2008144034A - Lubrication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubrication system improving lubricant-holding power of a foamed lubricant holding a lubricant component and maintaining the amount of the lubricant at the necessary minimum, having excellent compatibility in the initial lubrication and responsive to demands of a longer life and a lower cost. <P>SOLUTION: The lubrication system comprises the foamed lubricant 9 and grease 10 coexisting in the lubrication objective site. The foamed lubricant 9 contains the lubricant component in a resin which is foamed, cured and porosified. The grease 10 has ≥300 cone penetration. In the initial lubrication of the lubrication objective site, at least the grease 10 is present in a sliding part of the lubrication objective site. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lubrication system capable of supplying a lubricant to a sliding part and a rotating part of a mechanical device.

Generally, a lubricant is used in a sliding part and a rotating part of most machines represented by automobiles and industrial machines. Lubricants can be broadly divided into liquid lubricants and solid lubricants. Grease with increased lubricating oil and shape retention, and solids that retain liquid lubricant and prevent its scattering and dripping. Lubricants are also known.
For example, a solid lubricant in which ultra-high molecular weight polyolefin or urethane resin and its curing agent are mixed in lubricating oil or 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).
When such solid lubricant is sealed in a bearing and solidified, it gradually exudes lubricating oil. If this is used, maintenance for replenishing the lubricating oil becomes unnecessary, and there is a lot of moisture. It is intended to be useful for extending the life of the bearing even in environments where it is used or where inertia is strong.

When such a solid lubricant is used in a part where external stress such as compression or bending is frequently applied, such as a drive part of a constant velocity joint, a very large force is required to deform following the compression or bending. Or a very large stress is applied to the solid lubricant, and the mechanical strength is also required for the portion holding the solid lubricant.
However, since the strength and filling rate of the solid lubricant are usually compensatory, it is difficult to keep the lubricant at a high filling rate, which may hinder a longer life.
Therefore, there is a demand for a solid lubricant that can be easily used even at sites where external stress such as compression and bending repeatedly occurs at a high frequency.
As this solid lubricant, for example, a soft resin foamed to form continuous air holes is impregnated with lubricating oil, and a foamed lubricant that holds the lubricating oil in the pores is filled into the bearings or constant velocity joints. It is known to be used (see Patent Document 5).

However, although the solid lubricants according to Patent Documents 1 to 4 described above have a large lubricating oil retaining force, they do not have flexible deformability. In addition, the foamed lubricant of Patent Document 5 has a flexible deformability according to external force and can follow compression and bending deformation, but has a low lubricating oil retention and is used when used under high speed conditions such as a bearing. In some cases, the lubricating oil can quickly escape and be depleted. Such foamed lubricants can be used in short-time lubrication and sealed spaces, but when used in parts that require long-term lubrication or in open spaces, there will be insufficient supply of lubricating oil, or oil retention If it is weak, excess lubricating oil is repeatedly released and absorbed from the pores, and constantly flows in the space.
When the lubricant exuded excessively from such a solid lubricant or foamed lubricant comes into contact with the exterior such as rubber, the lubricant and its additives may be chemically corroded or deteriorated.

In addition, if the oozing of the lubricating oil is delayed for the purpose of prolonging the service life, the lubricating oil does not ooze into the sliding portion immediately after the start of lubrication of the lubrication target part in which the solid lubricant is enclosed. On the contrary, there is a problem that the lubrication target part has a short life due to the damage of the sliding surface due to the shortage. Therefore, a lubricant capable of supplying lubricating oil immediately after the start of lubrication is desired.
Further, in the process of manufacturing such a lubricant, a number of manufacturing processes are necessary for reliably impregnating the lubricating oil 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 cope with such problems, and improves the lubricant retention of the foamed lubricant that retains the lubricating component, and the amount of lubricant oozing due to deformation of the foamed lubricant. It is an object of the present invention to provide a lubrication system that can maintain the minimum required amount, has excellent conformability in initial lubrication, and can meet the demand for long life and low cost.

The lubrication system of the present invention is a lubrication system in which a foamed lubricant and grease coexist at a site to be lubricated, and the foamed lubricant contains a lubricating component in a resin that is foamed and cured to become porous. The grease has a consistency of 300 or more, and at the initial lubrication of the lubrication target site, at least the grease is present in the sliding portion of the lubrication target site.
In addition, the said penetration degree represents the 60 degree of penetration penetration measured based on JISK22205.3. Further, in the present invention, “initial lubrication” refers to a state in which a lubricant component does not ooze out from the foamed lubricant into the sliding portion immediately after the start of operation of the device requiring lubrication. Lubrication during the period until the lubricating component oozes out to the sliding part.

In the lubricating system of the present invention, the foamed lubricant is a resin that foams and hardens to become porous, and has rubber-like elasticity, and the lubricating component contained in the resin exhibits exudation due to deformation of the rubber-like elastic body. It is characterized by having.
In addition, the resin that is made porous by curing and curing is a polyurethane resin.
Further, the open cell ratio of the resin that is foamed and cured to become porous is 50% or more.
The foaming ratio of the resin is 1.1 to 100 times.

  In the lubricating system of the present invention, the foamed lubricant and the grease coexist at the site to be lubricated, and the foamed lubricant contains a lubricating component in the resin that is foamed and hardened to become porous. In the initial lubrication of the lubrication target site, at least the grease is present in the sliding portion of the lubrication target site, so in the initial lubrication until the lubrication component sufficiently oozes out from the foamed lubricant. In addition, the grease is present in the sliding portion and contributes to lubrication, and a lubricating function can be connected to the lubricating component that exudes from the foamed lubricant after the initial lubrication. For this reason, the lubrication function can be satisfactorily performed continuously without deficiency from the initial lubrication in a sliding portion such as a bearing or a universal joint in which the foamed lubricant is sealed.

  This foaming lubricant is a solid material obtained by foaming and curing a resin to make it porous, and the lubricating component is held in the resin when the resin is foamed and cured. For this reason, compared with the case where the foamed resin obtained by foaming / curing with only the resin is impregnated with the lubricating component, the retained amount of the lubricating component in the foamed lubricant is larger than the retained amount due to the impregnation in the pores. In addition, during operation of equipment using the present lubrication system, the lubricating component is gradually released from the foamed lubricant to the periphery of the sliding portion that requires lubrication, so that operation is possible even at high speed rotation.

  Since the grease can act as a lubricant in the initial lubrication, the oozing rate of the lubricating component from the foamed lubricant can be set smaller than when no grease is used. Therefore, the minimum necessary lubricating component can be stably supplied to the sliding portion over a long period of time, and the life of the device using the lubricating system of the present invention can be further extended.

  Also, by encapsulating foamed lubricant, the lubricant can be present near the sliding part of the equipment using this lubrication system, and it is easier to supply the lubricant to the sliding part than lubrication with grease alone. . In addition, since there are many porous portions, it is possible to reduce the weight of the equipment using this lubrication system.

  An example in which the lubrication system of the present invention is applied to a constant velocity universal joint will be given to specifically describe the action of the foamed lubricant and grease. FIG. 1 is a cross-sectional view showing a constant velocity universal joint using the lubrication system of the present invention. As shown in FIG. 1, the constant velocity universal joint that is a lubrication target part is an inner ring 1, an outer ring 2, an inner ring side track groove 3, an outer ring side track groove 4, a steel ball 5, a cage 6, a shaft 7, a boot 8, and a foaming lubricant. 9, grease 10 and other accessory parts. At this time, the grease 10 is accommodated in the bottom of the outer ring 2 as the lubrication target portion of the constant velocity universal joint, and the foamed lubricant 9 coexists in the form of being disposed near the steel ball 5.

  The foamed lubricant 9 contains a lubricating component in a foamed, cured and porous resin, and the centrifugal force generated by the rotation of the constant velocity universal joint and the compression generated when the constant velocity universal joint takes an angle. Lubricating components are applied to the inner ring side track groove 3, outer ring side track groove 4, steel ball 5 surface, cage 6 surface, etc., which are sliding parts from the foamed lubricant due to external stress such as bending and expansion and capillary action. Release slowly. Further, unlike the lubricating component in the foamed lubricant, the grease 10 accommodated in the bottom of the outer ring 2 is not contained in the resin, so that it can easily move in the constant velocity universal joint, and the constant velocity universal joint When starting, the sliding part in the joint can be reached. 1 shows an example in which the grease 10 is accommodated in the bottom of the outer ring 2, but the grease 10 is accommodated without any limitation as long as it reaches the sliding portion in the joint at the start of the constant velocity universal joint. be able to. Therefore, lubrication that tends to be insufficient at the initial stage of lubrication (initial stage of rotation) can be compensated.

  Foamed lubricant "releases the lubricating component to the outside by an external stress such as centrifugal force, compression, bending, expansion, etc.", so there is not enough lubricating component in the sliding part at the beginning of rotation There is a case. The grease is easy to move in the constant velocity universal joint due to the external stress described above. Therefore, even if only a small amount of grease is sealed at the bottom of the outer ring of the constant velocity universal joint, it can quickly move into the constant velocity universal joint and act as a lubricant until the lubricating component is sufficiently released from the foamed lubricant.

In the present invention, the foamed lubricant can be gradually released from between the molecules of the resin by causing the lubricating component to exude by deformation due to an external force such as compression, expansion, bending, and twisting due to the flexibility of the resin. At this time, the amount of the lubricating component such as the 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 foamed lubricant used in the present invention, the resin has a large surface area due to foaming, and the lubricating oil, which is an excess lubricating component that has oozed out, can be temporarily held in the foam bubbles again. The amount of lubricating oil that oozes out is stable, and by retaining the lubricating oil in the resin and impregnating the bubbles in the foam, the amount of the lubricating oil retained is larger than in the non-foamed state.

In addition, the foamed lubricant used in the present invention requires very little energy when bent compared to non-foamed materials, and can be flexibly deformed while retaining a lubricating component such as lubricating oil at a high density. Therefore, in the process of cooling after solidifying the foamed lubricant, even if the foamed lubricant contracts and embraces rolling elements etc., 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 foamed lubricant used in the present invention only foams and cures the mixture containing the lubricating component and the resin, no special equipment is required, and it can be filled in any place and molded. is there.
Further, the density of the foamed lubricant can be changed by controlling the blending amount of the blending components of the mixture.

In the present invention, the foaming / curing resin that forms the foamed lubricant is preferably a resin that has a rubber-like elasticity after foaming / curing and has an exudation property of a lubricating component due to deformation.
Foaming / curing may be in a form in which foaming / curing is performed when the resin is produced, or in a form in which a foaming agent is blended with the resin 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.

Examples of the resin that becomes porous by foaming and curing include rubber and plastic.
Examples of the rubber include 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.
Examples of plastic include general-purpose plastics such as polyurethane resin, polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, polyacetal resin, polyamide 4,6 resin, polyamide 6,6 resin, polyamide 6T resin, and polyamide 9T resin. Engineering plastics.
Among the above resins, a polyurethane resin that is easily foamed and cured to be 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 acylated products, etc. Obtained by addition polymerization in the presence of a catalyst. The polyether ester polyol is obtained by subjecting a polyester having a carboxyl group and / or an OH group to an addition reaction of 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 typified 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 in order to obtain a foamed lubricant, a known foaming means may be employed. For example, a chemical foaming method for generating a volatile gas by a chemical reaction, water, acetone, hexane or the like Physical methods for heating and vaporizing organic solvents with low boiling points, mechanical foaming methods for blowing inert gases such as nitrogen and air from the outside, azobisisobutyronitrile (AIBN), azodicarbonamide (ADCA), etc. Examples of such a method include using a decomposable foaming agent that is chemically decomposed by heat treatment or 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 resins, various adhesives such as urethane adhesives, cyanoacrylate adhesives, epoxy adhesives, polyvinyl acetate adhesives, polyimide adhesives, and the like can be used by foaming and curing. .

  In the present invention, various additives may be used as necessary in the resin that is foamed and cured to make it porous. 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 impregnated into the resin that is made porous by curing and foaming can be used as long as it does not dissolve the solid component that forms the foam. As the lubricating component, for example, lubricating oil, grease, wax and the like can be used alone or in combination of two or more.
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.
When the foamed and hardened resin and lubricating oil do not dissolve or disperse due to chemical compatibility such as polarity, it is easier to physically mix them by using a lubricating oil with a close viscosity, It becomes possible to prevent segregation of the lubricating oil.

  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. Examples of the diisocyanate include phenylene diisocyanate, diphenyl diisocyanate, phenyl diisocyanate, diphenylmethane diisocyanate, octadecane diisocyanate, decane diisocyanate, and hexane diisocyanate.
Examples of the monoamine include octylamine, dodecylamine, hexadecylamine, octadecylamine, oleylamine, aniline, p-toluidine, cyclohexylamine and the like.

  The polyurea compound is obtained, for example, by reacting diisocyanate with monoamine and 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.

  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.

  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.

  The lubricating components described above further include solid lubricants such as molybdenum disulfide and graphite, friction modifiers such as organic molybdenum, oily agents such as amines, fatty acids, and fats, antioxidants such as amines and phenols, Antirust agents such as petroleum sulfonates, dinonylnaphthalene sulfonates, sorbitan esters, extreme pressure agents such as sulfur and sulfur-phosphorus compounds, anti-wear agents such as organic zinc and phosphorus compounds, benzotriazole, sodium nitrite, etc. Various additives such as a metal deactivator, a viscosity index improver such as polymethacrylate and polystyrene may be included.

The foaming lubricant used in the present invention is obtained by foaming and curing a mixture containing the above-described lubricating component, resin, curing agent, and foaming agent.
The blending ratio of the lubricating component is 1 to 90% by weight, preferably 5 to 80% by weight, based on the entire mixture. When the lubricating component is less than 1% by weight, the supply amount of the lubricating component is small and the function as a foaming lubricant cannot be exhibited, and 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 the function as a foaming lubricant cannot be exhibited.

  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 each component when producing the foamed lubricant is not particularly limited, and for example, mixing using a generally used stirrer such as a Henschel mixer, ribbon mixer, juicer mixer, mixing head, etc. Can do.
The mixture preferably uses a surfactant such as a commercially available silicone foam stabilizer, and each raw material molecule is preferably dispersed uniformly. 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 foaming lubricant used in the present invention contains a lubricating component in a resin that is foamed and cured to become porous, and the lubricating component is externally applied by external forces such as compression, bending, centrifugal force, and expansion of bubbles due to temperature rise. It is possible to supply to.
The foaming lubricant preferably employs a reactive impregnation method in which a foaming reaction and a curing reaction of a resin are simultaneously performed in the presence of a lubricating component. In this way, it is possible to highly fill the inside of the resin with the lubricating component, 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 in which this is impregnated with a lubricating component does not allow a sufficient amount of liquid lubricating component to penetrate into the resin. However, if 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.

  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 is directly supplied from the surface of the resin to the outside through open cells by external stress. 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.

  In the present invention, the open cell ratio of the foamed lubricant is preferably 50% or more, more preferably 70% or more. If the open cell ratio is less than 50%, the ratio of the foamed, hardened, and porous resin in the resin temporarily taken up into the closed cells may not be supplied to the outside when necessary. is there.

The open cell ratio of the foamed lubricant used in the present invention can be calculated by the following procedure.
(1) The foamed and hardened foamed lubricant is cut into an appropriate size to obtain Sample A. The weight of sample A is measured.
(2) Sample A is washed with Soxhlet for 3 hours (solvent: petroleum benzine). Then leave it in a thermostatic bath at 80 ° C for 2 hours to completely dry the organic solvent and obtain Sample B. The weight of sample B is measured.
(3) The open cell ratio is calculated by the following procedure.
Open cell ratio = (1- (resin weight of sample B−resin weight of sample A) / weight of lubricating component of sample A) × 100
In addition, the resin weight of sample A and B and the lubrication component weight are calculated by multiplying the weight of sample A and B by the preparation ratio of the composition.
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 foamed 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.

Foamed lubricant may be foamed and cured after pouring a mixture containing a lubricating component and resin into the lubrication target member, and after foaming and curing at normal pressure, it is post-processed to the desired shape by cutting or grinding However, it can also be incorporated in the lubrication target member.
In the present invention, it is possible to easily fill any part of the member to be lubricated with 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 employ a method of pouring the resin into the lubrication target member before foaming / curing and foaming / curing in the member. By adopting this method, the manufacturing process is simplified and the cost can be reduced.

In the lubrication system of the present invention, the grease that can coexist with the foamed lubricant and the lubrication target part can be used as long as the 60-time penetration measured according to JIS K 2220 5.3 is 300 or more. If the consistency is less than 300, the fluidity is insufficient to contribute to the initial lubrication, and the lubricant may not be supplied quickly where it is needed.
Specific examples of the grease include grease that can be used as a lubricating component of the foamed lubricant. Similarly, various additives can be included.
Further, the grease in the lubrication system can contribute to the initial lubrication of the lubrication system by being present at least in the sliding portion of the lubrication target portion.

<Preparation of grease for initial lubrication>
Greases A to C used in Examples 1 to 4 and Comparative Examples 3 to 4 were prepared by the following method.
Grease A
Grease A was prepared by reacting 9.16 g of diphenylmethane-4,4-diisocyanate and 7.84 g of p-toluidine in 83 g of mineral oil (turbine 100: manufactured by Nippon Oil Corporation), and uniformly dispersing the diurea compound produced. Got. The penetration was measured to be 335.
Grease B
In 92 g of mineral oil (turbine 100: manufactured by Nippon Oil Corporation), 3.94 g of diphenylmethane-4,4-diisocyanate and 4.07 g of octylamine were reacted, and the resulting diurea compound was uniformly dispersed to obtain grease B. Obtained. The consistency measured was 320.
Grease C
In 88 g of mineral oil (turbine 100: manufactured by Nippon Oil Co., Ltd.), 5.9 g of diphenylmethane-4,4-diisocyanate and 6.1 g of octylamine are reacted, and the resulting diurea compound is uniformly dispersed to obtain grease C. Obtained. The consistency measured was 270.

Example 1 to Example 2
First, as shown in FIG. 1, on the bottom of the outer ring of an outer ring 2, an inner ring 1, a cage 6 and a steel ball 5 which are fixed type eight ball joint subassies (EBJ82 outer diameter size 72.6 mm manufactured by NTN Corporation) 5 g of the initial lubrication grease was sealed. Next, among the compositions shown in Table 1, (a), (d), (e), and (i) were mixed well at 80 ° C, and then (b) dissolved at 120 ° C was added and mixed rapidly. Finally, (c) and (h) were added and stirred, and then 15.0 g was sealed in the above-mentioned joint filled with initial lubricating grease. After a few seconds, the foaming reaction started and allowed to stand for 30 minutes in a thermostatic chamber set at 100 ° C. to cure, and a test piece of a constant velocity universal joint using a lubrication system was assembled by assembling other sections such as boots and shafts. The obtained test piece was subjected to the following initial characteristic test and life test, and the state of appearance of the initial characteristic and the life time were measured. Further, the open cell ratio of the foamed lubricant was measured based on the above-described method for calculating the open cell ratio. The results are also shown in Table 1.

<Initial characteristic test using constant velocity universal joint>
In order to evaluate whether or not the desired initial characteristics were obtained, the constant velocity universal joint test piece was evaluated under the following conditions. When the outer ring surface temperature exceeded 100 ° C during the test, the test was terminated due to abnormal temperature rise. In addition, after the test, the inside of the test piece is inspected, and “○” is recorded when no internal damage such as wear or peeling is observed, and “X” is recorded when damage is confirmed.
・ Torque 451 N ・ m
・ Angle 6 deg
・ Rotation speed 580 rpm
・ Test time 1 hour

<Life test using constant velocity universal joint>
In order to evaluate the improvement in durability, the constant velocity universal joint test piece was evaluated on the actual machine under the following conditions. When the outer ring surface temperature exceeded 100 ° C during the test, the test was terminated due to abnormal temperature rise. In addition, after the test that has passed the specified time, the inside of the test piece is inspected, and if there is no internal damage such as abnormal wear or peeling, or if there is internal damage but it is minor and can be continuously operated, “○” is recorded as “X”, indicating that damage is severe and continuous operation is impossible.
・ Torque 725 N ・ m
・ Angle 6 deg
・ Rotation speed: 230 rpm
・ Test time 150 hours

Example 3 to Example 4
First, as shown in FIG. 1, on the bottom of the outer ring of an outer ring 2, an inner ring 1, a cage 6 and a steel ball 5 which are fixed type eight ball joint subassies (EBJ82 outer diameter size 72.6 mm manufactured by NTN Corporation) 5 g of the initial lubrication grease was sealed. In the component amounts (composition) shown in Table 1, silicone-based foam stabilizer, mineral oil, amine-based catalyst, and water as a blowing agent were added to the polyether polyol, and the mixture was heated at 90 ° C. and stirred well. After adding isocyanate to this and stirring well, 13.0 g was sealed in the joint containing the initial lubricating grease. After a few seconds, the foaming reaction started, and it was allowed to stand for 15 minutes in a thermostat set at 90 ° C. to cure, and a test piece of a constant velocity universal joint using a lubrication system was obtained by assembling other sections such as boots and shafts. The same items as in Example 1 were measured. The results are also shown in Table 1.

Comparative Example 1
A constant velocity universal joint specimen with the composition shown in Table 1 was prepared in the same procedure as in Example 2, but the initial lubricating grease was not enclosed. The same items as in Example 1 were measured. The results are also shown in Table 1.

Comparative Example 2
A constant velocity universal joint specimen with the composition shown in Table 1 was prepared in the same procedure as in Example 3, but the initial lubricating grease was not enclosed. The same items as in Example 1 were measured. The results are also shown in Table 1.

Comparative Example 3
A constant velocity universal joint specimen was obtained in the same procedure as in Example 1 with the composition shown in Table 1. As the initial lubricating grease, grease C having a consistency of 270 was used. The same items as in Example 1 were measured. The results are also shown in Table 1.

Comparative Example 4
Although the constant velocity universal joint test piece was produced by the same procedure as Example 4 with the composition shown in Table 1, the silicone type foam stabilizer was not used. As the initial lubricating grease, grease B having a consistency of 320 was used. The same items as in Example 1 were measured. The results are also shown in Table 1.

  In Examples 1 to 4, wear or the like due to an initial lack of lubricant was not confirmed even in an initial characteristic test using an actual constant velocity universal joint, and good results were shown. In Comparative Examples 1 to 3, wear was confirmed in the sliding portion in the initial characteristic test. In Comparative Example 1 and Comparative Example 2, it is considered that the lubricant was insufficient because the release of the lubricating component was not in time at the initial stage. In Comparative Example 3, since the fluidity of the grease used for the initial lubrication was inferior, it was considered that the grease was not supplied quickly to the sliding portion and the initial lack of lubricant could not be compensated.

  The lubrication system of the present invention improves the lubricant retention of the foaming lubricant that retains the lubricating component, and can suppress the amount of lubricant oozing due to deformation of the foaming lubricant to the minimum necessary, and the initial lubrication. It has excellent compatibility with the product, can meet the demand for long life and low cost. Therefore, it can be suitably used as a lubrication system for various rolling bearings and universal joints used for various industrial machines and automobiles.

It is sectional drawing which shows the constant velocity universal joint using the lubrication system of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner ring 2 Outer ring 3 Inner ring side track groove 4 Outer ring side track groove 5 Steel ball 6 Cage 7 Shaft 8 Boot 9 Foamed lubricant 10 Grease

Claims (5)

A lubrication system in which foamed lubricant and grease coexist in the lubrication target part,
The foamed lubricant comprises a lubricating component in a resin that is foamed and cured to become porous, and the grease has a consistency of 300 or more,
In the initial lubrication of the lubrication target site, at least the grease is present in the sliding portion of the lubrication target site.   The foamed lubricant is characterized in that a resin that foams and hardens to become porous has rubber-like elasticity, and a lubricating component contained in the resin has exudation properties due to deformation of the rubber-like elastic body. Item 2. The lubrication system according to Item 1.   3. The lubrication system according to claim 1, wherein the resin that is foamed and cured to become porous is a polyurethane resin.   The lubrication system according to claim 1, wherein the open cell ratio of the resin that is foamed and cured to be porous is 50% or more.   The lubrication system according to any one of claims 1 to 4, wherein a foaming ratio of the resin is 1.1 to 100 times.

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