Oil / seal lubrication system

Abstract

An oil / seal lubrication system provided with a seal member and a sliding member that moves relative to the seal member and is in contact with the seal member via a lubricating oil, the seal member containing an inorganic filler, and at least one of the seal member and the lubricating oil containing an ashless friction modifier.

Description

Technical Field

[0001] This invention relates to oil / sealing lubrication systems. Background Technology

[0002] In mechanical components such as hydraulic machinery, compression machinery, turbines, gear components, and bearings used in automobiles and industrial machinery, lubricating oil is used to improve the lubricity of sliding components, and sealing components (oil seals) are provided to prevent the lubricating oil from leaking from the mechanical components.

[0003] The sealing component comes into contact with and slides against sliding components such as rotating shafts and hydraulic cylinders. Therefore, for such sliding components, there is a need for sealing components that offer high sealing performance and achieve low friction by reducing sliding resistance. For example, Patent Document 1 discloses a fluororubber composition suitable for use as a sealing material that maintains sealing performance and achieves low friction by increasing the oil pump flow rate from the initial use of the oil seal until wear. This fluororubber composition contains, relative to 100 parts by weight of fluororubber, 1 to 100 parts by weight of a needle-like or fibrous filler with an average particle size of 5 μm or less, an average particle length of 40 to 60 μm, and an aspect ratio of 10 to 12.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: International Publication No. 2014 / 024661 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] One aspect of the present invention is to provide an oil / seal lubrication system capable of achieving low friction between a sealing member and a sliding member, wherein the sliding member moves relative to the sealing member and contacts the sealing member via lubricating oil.

[0009] Solution for solving the problem

[0010] According to the research of the inventors, it has been found that by including an inorganic filler material in the sealing member and including at least one of the sealing member and the lubricating oil in an ashless friction modifier, low friction can be achieved.

[0011] The present invention includes the following aspects.

[0012] [1] An oil / seal lubrication system comprising: a sealing member; and a sliding member that moves relative to the sealing member and contacts the sealing member via a lubricating oil, the sealing member containing an inorganic filler material, and at least one of the sealing member and the lubricating oil containing an ashless friction modifier.

[0013] [2] According to the oil / seal lubrication system described in [1], both the sealing component and the lubricating oil contain an ashless friction modifier.

[0014] [3] The oil / sealing lubrication system according to [1] or [2], wherein the inorganic filler material is at least one selected from the group consisting of carbon black, metal oxides, metal hydroxides and silicate minerals.

[0015] [4] The oil / seal lubrication system according to any one of [1] to [3], wherein the ashless friction modifier is at least one selected from the group consisting of fatty acid ester compounds, phosphorus compounds, ether compounds, alcohol compounds, amide compounds, amine compounds, imide compounds, sulfur compounds and phosphorus-sulfur compounds.

[0016] [5] The oil / seal lubrication system according to any one of [2] to [4], wherein the friction modifier in the sealing member and the friction modifier in the lubricating oil are fatty acid ester compounds.

[0017] [6] According to the oil / seal lubrication system of [5], wherein the fatty acid ester compound contains a compound having a hydrocarbon group, an ester group and a hydroxyl group.

[0018] [7] An oil / seal lubrication system according to any one of [1] to [6], wherein the lubricating oil contains at least one base oil selected from the group consisting of base oils classified as any one of the API base oil classifications of Group I, Group II, Group III, Group IV and Group V.

[0019] [8] An oil / seal lubrication system according to any one of [1] to [7], wherein the lubricating oil contains a base oil having a viscosity index of 80 or higher.

[0020] [9] An oil / seal lubrication system according to any one of [1] to [8], wherein the lubricating oil contains %C P For 60 and above, %C A It is a base oil with a strength of 5 or less.

[0021]

[10] The oil / seal lubrication system according to any one of [1] to [8], wherein the lubricating oil contains an oxygen-containing base oil.

[0022]

[11] The oil / seal lubrication system according to any one of [1] to

[10] , wherein the coefficient of friction measured by an MTM tester using a sealing member and lubricating oil is 0.050 or less.

[0023] The effects of the invention

[0024] According to one aspect of the invention, an oil / seal lubrication system capable of achieving low friction between a sealing member and a sliding member, wherein the sliding member moves relative to the sealing member and contacts the sealing member via lubricating oil, can be provided. Attached Figure Description

[0025] Figure 1 This is a schematic diagram illustrating one embodiment of an oil / seal lubrication system. Detailed Implementation

[0026] Hereinafter, embodiments of the present invention will be described with appropriate reference to the accompanying drawings. Figure 1 This is a schematic cross-sectional view illustrating one embodiment of an oil / seal lubrication system.

[0027] like Figure 1 As shown, in one embodiment, the oil / sealing lubrication system 1 is installed in the annular gap between two concentrically assembled components, namely the housing 2 and the rotating shaft (sliding member) 3, and seals the annular gap. This prevents leakage of the sealing object, such as lubricating oil, present on the sealing object side O.

[0028] The oil / sealing lubrication system 1 includes: an annular sealing member 5, which fits into the inner circumferential surface of a shaft hole provided in the housing 2; and a reinforcing ring 4, which fits into the sealing member 5 and provides rigidity. The reinforcing ring 4 is a metal annular member with an L-shaped cross-section, having a cylindrical portion 4a provided along the inner circumferential surface of the shaft hole, and an inwardly extending flange portion 4b extending radially inward from the atmospheric side A end of the cylindrical portion 4a. The sealing member 5 is composed of a rubber-like elastomer integrally sintered and fixed from the outer circumferential surface of the cylindrical portion 4a of the reinforcing ring 4 to the atmospheric side A end face and the sealing object side O end face of the inwardly extending flange portion 4b.

[0029] In the sealing member 5, the outer peripheral sealing portion 6, which is fixed to the outer peripheral surface of the cylindrical portion 4a of the reinforcing ring 4, has a predetermined interference fit with respect to the inner peripheral surface of the shaft hole of the housing 2. The outer peripheral sealing portion 6 is firmly fixed to the inner peripheral surface of the shaft hole by the fitting rigidity generated by the cylindrical portion 4a of the reinforcing ring 4, and prevents leakage of the sealing object from the inner peripheral surface of the shaft hole. Furthermore, in another embodiment, a structure can be adopted in which the cylindrical portion 4a of the reinforcing ring 4 is directly fitted into the inner peripheral surface of the shaft hole without providing the outer peripheral sealing portion 6 (metal fitting type).

[0030] On the rotating shaft 3 side of the sealing member 5, a sealing lip 7 is provided, extending from the inner end of the inner flange portion 4b of the reinforcing ring 4 towards the sealing object side O along the inner diameter direction, and a dustproof lip 8 extends in the opposite direction towards the atmospheric side A along the inner diameter direction. The dustproof lip 8 is plate-shaped, and its front end slides freely into sealing contact with the circumferential surface of the rotating shaft 3. This prevents the intrusion of dust from the atmospheric side A.

[0031] The sealing lip 7 has: a sealing object-side inclined surface 9 facing the sealing object side O, an atmospheric side inclined surface 11 facing the atmospheric side A, and a sliding surface 10 disposed between the sealing object-side inclined surface 9 and the atmospheric side inclined surface 11. The sealing object-side inclined surface 9 of the sealing lip 7 is inclined such that the distance between it and the circumferential surface of the rotation shaft 3 gradually increases from the end edge of the sliding surface 10 towards the sealing object side O. The atmospheric side inclined surface 11 of the sealing lip 7 is inclined such that the distance between it and the circumferential surface of the rotation shaft 3 gradually increases from the end edge of the sliding surface 10 towards the atmospheric side A.

[0032] Between the inclined surface 9 on the sealing object side and the inclined surface 11 on the atmospheric side, a sliding surface 10 is provided along the circumference of the rotation axis 3. That is, the front end of the sealing lip 7 is continuously formed with the inclined surface 9 on the sealing object side, the sliding surface 10 and the inclined surface 11 on the atmospheric side from the sealing object side O to the atmospheric side A, forming a flat sliding part with a generally trapezoidal cross section.

[0033] The front end of the sealing lip 7 has a predetermined interference fit relative to the circumferential surface of the rotating shaft 3. Furthermore, a clamping spring 14 is installed on the outer circumference of the sealing lip 7, located on the back of the sliding surface 10. This clamping spring 14 applies a clamping force to the front end of the sealing lip 7 against the rotating shaft 3. Therefore, when the oil / sealing lubrication system 1 is installed on the rotating shaft 3, the sealing lip 7 undergoes elastic deformation by expanding its diameter, and through its elastic restoring force, it slides freely into sealing contact with the circumferential surface of the rotating shaft 3.

[0034] The rotating shaft 3 is suitable for use with a hard material. Examples of hard materials include carbon steel, low-alloy steel, stainless steel, or materials with surface coatings. The hardness of this hard material can be 10 HRC or higher, 20 HRC or higher, or 30 HRC or higher, and preferably 40 HRC or higher or 50 HRC or higher under conditions of easy wear. The surface roughness of the circumferential surface of the rotating shaft 3 (the part in contact with the sealing member 5) can be 1 μm Ra or less, 0.6 μm Ra or less, or 0.5 μm Ra or less, and preferably 10 μm Rz or less, 6 μm Rz or less, or 4 μm Rz or less.

[0035] The aforementioned oil / sealing lubrication system 1 is suitable for applications such as rotating shafts in various industrial machinery, information electronic equipment, OA equipment, home appliances, drones, gear components, bearings, and other mechanical components, including automobiles, electric vehicles, motorcycles, bicycles, aircraft, railway vehicles, construction machinery, agricultural machinery, hydraulic machinery, compression machinery, robots, turbines, and semiconductor manufacturing equipment. The higher the rotational speed of the rotating shaft, the greater the energy savings and heat suppression resulting from low friction, leading to improved durability of the sealing components, lubricating oil, and rotating shaft. Therefore, the oil / sealing lubrication system 1 of this embodiment is particularly preferred for use with such high-speed rotating shafts. It should be noted that this embodiment describes its application in rotating shafts as an example; however, in another embodiment, the oil / sealing lubrication system can also be applied to shock absorbers, hydraulic cylinders, and other components of the aforementioned mechanical components.

[0036] The oil / sealing lubrication system 1 is suitable for use in electric vehicles (EVs). It is particularly suitable for the motor drive unit of EV drive systems (e-Axle), where it can suppress torque and reduce wear on the sealing components 5, thus extending their lifespan. Additionally, the oil / sealing lubrication system 1 is also suitable for robots that operate at speeds lower than those of automotive engines and require frequent reversing.

[0037] The sealing component 5 contains an inorganic filler material. The inorganic filler material can be in the form of granules, fibers, layers, blocks, strips, columns, etc.

[0038] As an inorganic filler material, at least one selected from the group consisting of carbon black, metal oxides, metal hydroxides, and silicate minerals can be used. Examples of the aforementioned metal oxides include iron(III) oxide (Fe₂O₃), chromium(III) oxide (Cr₂O₃), titanium dioxide (TiO₂), aluminum oxide (Al₂O₃), magnesium oxide (MgO), and zinc oxide (ZnO). Examples of the aforementioned metal hydroxides include magnesium hydroxide and aluminum hydroxide. Examples of the aforementioned silicate minerals include silica, wollastonite, talc, and mica. Among these, from the viewpoint of availability and adsorption to ashless friction modifiers, metal oxides, metal hydroxides, or silicate minerals are preferred; iron(III) oxide, chromium(III) oxide, titanium dioxide, aluminum hydroxide, silica, wollastonite, or talc are preferred; iron(III) oxide, chromium(III) oxide, titanium dioxide, aluminum hydroxide, or wollastonite are more preferred; and iron(III) oxide, chromium(III) oxide, titanium dioxide, or aluminum hydroxide are even more preferred. From the viewpoint of obtaining a particularly significant effect of low friction due to the friction modifier described later, iron-based filler materials are preferred as inorganic filler materials, and even more preferred filler materials containing iron oxide (III).

[0039] The content of inorganic filler material is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, particularly preferably 50 parts by mass or more, preferably 300 parts by mass or less, more preferably 250 parts by mass or less, even more preferably 200 parts by mass or less, and particularly preferably 150 parts by mass or less, relative to 100 parts by mass of rubber component 5.

[0040] In one embodiment, the sealing member 5 can be a vulcanized molded body (also known as a cross-linked molded body) of a rubber composition containing a rubber component and an inorganic filler material. In other words, the sealing member may contain a rubber component (vulcanized (cross-linked) rubber) in addition to the inorganic filler material. The sealing member 5 is obtained by hot pressing (primary vulcanization) the rubber composition at 160~200°C for 3~30 minutes, and then, as needed, by secondary vulcanization at 150~250°C for 0.5~24 hours.

[0041] There is no particular limitation on the type of rubber component. Examples of rubber components include natural rubber, styrene-butadiene rubber, butadiene rubber, chloroprene rubber, acrylonitrile-butadiene rubber (nitrile rubber, NBR), hydrogenated nitrile rubber, isoprene rubber, butyl rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber (EPDM), acrylate rubber (ACM), fluororubber (FKM), and silicone rubber. Preferably, the rubber component is selected from at least one group consisting of fluororubber (FKM), acrylonitrile-butadiene rubber (nitrile rubber, NBR), silicone rubber, and acrylate rubber (ACM).

[0042] Examples of fluororubbers include those capable of polyol vulcanization and those capable of peroxide crosslinking. Fluororubbers capable of polyol vulcanization are preferred.

[0043] Examples of fluororubbers capable of polyol vulcanization include homopolymers, copolymers (e.g., alternating copolymers), or copolymers of these fluorinated monomers with propylene, such as vinylidene fluoride, hexafluoropropylene, pentafluoropropylene, trifluoroethylene, trifluorochloroethylene, tetrafluoroethylene, fluoroethylene, perfluoroacrylates, perfluoroalkyl acrylates, perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), and perfluoro(propyl vinyl ether). Fluororubbers capable of polyol vulcanization are preferably vinylidene fluoride-hexafluoropropylene copolymers, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymers, and tetrafluoroethylene-propylene copolymers. Commercially available fluororubbers capable of polyol vulcanization can also be used directly.

[0044] Examples of fluororubbers capable of peroxide crosslinking include fluorinated elastomers that contain iodine and / or bromine as crosslinking sites in their molecules. The fluorine content in peroxide-crosslinkable fluororubbers can range from 63% to 71% by weight. The Mooney viscosity (ML) of peroxide-crosslinkable fluororubbers is... 1+10 (121℃) can be 20~100.

[0045] The introduction of iodine and / or bromine groups into fluororubber capable of peroxide crosslinking can be achieved through copolymerization in the presence of saturated or unsaturated compounds containing iodine and / or bromine groups.

[0046] When the side chains of fluororubber contain bromine and / or iodine groups, for example, perfluoro(2-bromoethyl vinyl ether), 3,3,4,4-tetrafluoro-4-bromo-1-butene, 2-bromo-1,1-difluoroethylene, bromotrifluoroethylene, perfluoro(2-iodoethyl vinyl ether), iodotrifluoroethylene, etc., can form monomers at their crosslinking sites and copolymerize with the above-mentioned fluorinated monomers.

[0047] When the ends of fluororubber contain iodine and / or bromine groups, the formula X can be used. 1 C n F 2n X 2 (X) 1 F, Br or I, X 2 The terminator is a terminal fluorine halide compound (Br or I, n: an integer from 1 to 12). From the perspective of balancing reactivity and operability, compounds with n of 1 to 6 are preferred as terminal fluorine halide compounds. Specifically, copolymers containing iodine and / or bromine groups are preferred, obtained by copolymerizing terminal fluorine halide compounds such as 1-bromoperfluoroethane, 1-bromoperfluoropropane, 1-bromoperfluorobutane, 1-bromoperfluoropentane, 1-bromoperfluorohexane, 1-iodoperfluoroethane, 1-iodoperfluoropropane, 1-iodoperfluorobutane, 1-iodoperfluoropentane, and 1-iodoperfluorohexane with the aforementioned fluorine-containing monomers.

[0048] In X 1 and X 2 In the case of I or Br, crosslinking sites are introduced at the ends of the fluororubber. As X 1 and X 2Compounds containing either I or Br include, for example, 1-bromo-2-iodotetrafluoroethane, 1-bromo-3-iodoperfluoropropane, 1-bromo-4-iodoperfluorobutane, 2-bromo-3-iodoperfluorobutane, monobromomonoiodoperfluoropentane, monobromomonoiodoperfluorohexane, 1,2-dibromoperfluoroethane, 1,3-dibromoperfluoropropane, 1,4-dibromoperfluorobutane, 1,5-dibromoperfluoropentane, 1,6-dibromoperfluorohexane, 1,2-diiodoperfluoroethane, 1,3-diiodoperfluoropropane, 1,4-dibromoperfluorobutane, 1,5-dibromoperfluoropentane, 1,6-dibromoperfluorohexane, etc.

[0049] Fluororubbers capable of peroxide crosslinking are preferably copolymer elastomers as described below.

[0050] Fluororubber with iodine and / or bromine groups introduced into a copolymer elastomer comprising approximately 50-80 mol% vinylidene fluoride, approximately 15-50 mol% hexafluoropropylene, and approximately 30-0 mol% tetrafluoroethylene.

[0051] As such fluororubbers, commercially available products can be used, such as Viton GAL200S, GBL200S, GBL600S, GF200S, and GF600S manufactured by DuPont; Tecnoflon P457, P757, P459, and P952 manufactured by Solvay; and DAI-EL G952, G901, G902, G912, and G801 manufactured by DAIKIN INDUSTRIES, LTD.

[0052] • Fluororubber containing about 50-85 mol% of vinylidene fluoride, about 5-50 mol% of perfluorovinyl ether represented by the formula: CF2=CFORf (Rf: a perfluoroalkyl group (preferably perfluoromethyl) with 1-10 carbon atoms or a perfluorooxyalkyl group with 1-10 carbon atoms having one or more ether bonds in the carbon chain), and about 50-0 mol% of tetrafluoroethylene, with iodide and / or bromine groups introduced into the copolymer elastomer.

[0053] As such fluororubber, commercially available products can be used, such as Viton GLT200S, GLT600S, GBLT200S, GBLT600S, GFLT200S, GFLT600S manufactured by DuPont, Tecnoflon PL455, PL855, PL557, PL458, PL958 manufactured by Solvay, and DAI-EL LT302, LT301 manufactured by DAIKIN INDUSTRIES, LTD.

[0054] The rubber composition may also contain a vulcanizing agent (crosslinking agent). Examples of vulcanizing agents (crosslinking agents) include polyols and organic peroxides. When the fluororubber is a fluororubber capable of polyol vulcanization, a polyol is preferred. When the fluororubber is a fluororubber capable of peroxide crosslinking, an organic peroxide is preferred.

[0055] Examples of polyols include 2,2-bis(4-hydroxyphenyl)propane [bisphenol A], 2,2-bis(4-hydroxyphenyl)perfluoropropane [bisphenol AF], bis(4-hydroxyphenyl)sulfone [bisphenol S], 2,2-bis(4-hydroxyphenyl)methane [bisphenol F], bisphenol A-bis(diphenyl phosphate), 4,4'-dihydroxybiphenyl, and 2,2-bis(4-hydroxyphenyl)butane. Bisphenol A or bisphenol AF are preferred. These polyols can be in the form of alkali metal salts or alkaline earth metal salts.

[0056] The polyol content can be 2 parts or more, preferably 2.5 parts or more, or 20 parts or less, preferably 15 parts or less, relative to 100 parts by mass of fluororubber capable of polyol vulcanization.

[0057] Polyols can be used in conjunction with vulcanization accelerators. That is, the rubber composition may also contain vulcanization accelerators. The vulcanization accelerator may be a quaternary phosphonium salt or a quaternary ammonium salt, preferably a quaternary phosphonium salt. The content of the quaternary phosphonium salt may be 0.5 parts by mass or more, preferably 1 part by mass or more, but may be 10 parts by mass or less, preferably 5 parts by mass or less, relative to 100 parts by mass of fluororubber capable of polyol vulcanization.

[0058] Quaternary phosphorus salts are derived from the formula: [PR 1 R 2 R 3 R 4 ] + X - The compound represented.

[0059] In the formula, R 1 ~R 4 Each is independently an alkyl, alkoxy, aryl, alkylaryl, aralkyl, or polyoxyalkylene group having 1 to 25 carbon atoms. - For Cl - ,Br - I - HSO4 - H2PO4 - RCOO - ROSO2 - or CO3 2- 2-3 R's 1 ~R 4 It can form a ring structure together with P.

[0060] Examples of quaternary phosphonium salts include tetraphenylphosphonium chloride, benzyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, triphenylmethoxymethylphosphonium chloride, triphenylmethylcarbonylmethylphosphonium chloride, triphenylethoxycarbonylmethylphosphonium chloride, trioctylbenzylphosphonium chloride, trioctylmethylphosphonium chloride, trioctylethylphosphonium acetate, tetraoctylphosphonium chloride, and trioctylethylphosphonium dimethyl phosphate. Quaternary phosphonium salts can also be polyhydroxy aromatic compounds—quaternary phosphonium compounds—as described in Japanese Patent Application Publication No. 61-12741, and other molar molecular compounds.

[0061] Quaternary ammonium salts are derived from the formula: [NR] 1 R 2 R 3 R 4 ] + X - The compound represented by R. 1 ~R 4 and X - R in the above quaternary phosphonium salts 1 ~R 4 and X - The meaning is the same. As quaternary ammonium salts, for example, 1-alkylpyridinium salts, 5-aralkyl-1,5-diazabicyclo[4,3,0]non-5-enium salts, 8-aralkyl-1,8-diazabicyclo[5,4,0]undec-7-enium salts, etc.

[0062] Examples of organic peroxides include dicumyl peroxide, cumyl hydroperoxide, terpene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, di-tert-butyl peroxide, benzoyl peroxide, m-toluyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxide)hexane, 2,5-dimethyl-2,5-di(tert-butylperoxide)-3-hexyne, 1,3-di(tert-butylperoxide isopropyl)benzene, 2,5-dimethyl-2,5-dibenzoylperoxide, (1,1,3,3-tetramethylbutylperoxide)2-ethylhexanoate, tert-butyl peroxide, tert-butyl perlaurate, di(tert-butylperoxide)adipate, di(2-ethoxyethylperoxide)dicarbonate, bis-(4-tert-butylcyclohexylperoxide)dicarbonate, etc.

[0063] The content of organic peroxide can be 0.5 parts by mass or more, preferably 1 part by mass or more, but less than 10 parts by mass, and preferably less than 5 parts by mass, relative to 100 parts by mass of fluororubber capable of peroxide crosslinking.

[0064] From the viewpoint of improving the mechanical strength and compression set of sealing components, it is preferable to use a combination of organic peroxide and a multifunctional unsaturated compound. Examples of multifunctional unsaturated compounds include tri(meth)allyl isocyanurate, tri(meth)allyl cyanurate, triallyl trimellitate, N,N'-m-phenylene bismaleimide, diallyl phthalate, tri(diallylamine)triazine, triallyl phosphite, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and 1,3-polybutadiene. Here, (meth)allyl refers to allyl or methylallyl. (meth)acrylate refers to acrylate or methacrylate.

[0065] Compared to 100 parts by mass of fluororubber capable of peroxide crosslinking, the content of the multifunctional unsaturated compound can be 0.1 parts by mass or more, preferably 0.5 parts by mass or more, and can be 20 parts by mass or less, preferably 10 parts by mass or less.

[0066] The sealing component 5 may also contain other components. Examples of other components include, for instance, ashless friction modifiers (details below) and reinforcing agents.

[0067] The rubber composition is obtained by mixing the above components using a kneader or open mill. The sealing component can be obtained by forming the obtained rubber composition into strip or granular preforms using an extruder or similar means, followed by appropriate molding and vulcanization. When the sealing component contains inorganic fillers and ashless friction modifiers, the ashless friction modifiers and inorganic fillers can be added separately to the rubber components, or the ashless friction modifiers can be pre-treated to adsorb onto the surface of the inorganic filler before being added to the rubber components.

[0068] Lubricating oil is present on the sealing object side O of the oil / seal lubrication system 1, and also between the circumferential surface of the rotating shaft 3 and the sliding surface 10 of the front end of the sealing lip 7 in the sealing member 5. The rotating shaft 3 contacts the sealing member 5 (the sliding surface 10 of the front end of the sealing lip 7) via the lubricating oil and moves relative to the sealing member 5.

[0069] Lubricating oils contain base oils. Examples of base oils include hydrocarbon oils and oxygenated oils. Examples of hydrocarbon oils include mineral oils, alkylbenzenes, alkylnaphthalenes, polyalphaolefins, polybutene, and ethylene-alpha olefin copolymers. Examples of oxygenated oils include esters and ethers. Examples of esters include polyol esters and complex esters. Examples of ethers include polyalkylene glycols, polyvinyl ethers, diphenyl ethers, dimethylsiloxanes, perfluoropolyethers, etc.

[0070] The hydrocarbon oil is preferably mineral oil or isoalkanes. Examples of mineral oils include: alkane-based mineral oils (n-alkanes, isoalkanes, etc.), cycloalkanes, and aromatic mineral oils, obtained by refining lubricating oil fractions from crude oil through atmospheric and / or vacuum distillation using two or more solvents alone or in appropriate combinations, such as deasphalting, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing, and clay treatment. Isoalkanes can be substances containing isoalkanes as the main component, obtained by hydrocracking and / or hydroisomerizing paraffin components obtained in the above dewaxing process or Fischer-Tropsch synthesis.

[0071] Oxygenated oils are preferably polyol esters. Polyol esters are esters of polyols and carboxylic acids, and more preferably esters of polyols and fatty acids.

[0072] The polyol constituting the polyol ester can be a polyol having 2 to 6 hydroxyl groups. The polyol can have 4 to 12 carbon atoms. Examples of hindered alcohols include neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, bis(trimethylolpropane), tri(trimethylolpropane), pentaerythritol, and dipentaerythritol. Preferably, the polyol is at least one selected from the group consisting of trimethylolpropane, pentaerythritol, and dipentaerythritol.

[0073] The fatty acids constituting the polyol ester can be saturated or unsaturated fatty acids. In one embodiment, when the polyol is trimethylolpropane, the fatty acids preferably contain unsaturated fatty acids. In another embodiment, when the polyol is pentaerythritol or dipentaerythritol, the fatty acids preferably contain saturated fatty acids.

[0074] Unsaturated fatty acids can have 14 or more carbon atoms or fewer than 20. Examples of unsaturated fatty acids include: physeteric acid, myristoleic acid, palmitoleic acid, heptadecanoic acid, octadecenoic acid, transoleic acid, oleic acid, and isoleic acid. Oleic acid is a preferred component of unsaturated fatty acids.

[0075] The number of carbon atoms in saturated fatty acids is preferably 4 or more, preferably 20 or less, more preferably 18 or less, and even more preferably 9 or less. Examples of saturated fatty acids include butyric acid, valeric acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid, and eicosanoic acid. These saturated fatty acids can be linear or branched.

[0076] In one embodiment, the complex ester can be a complex ester of a polyol and a polycarboxylic acid and at least one selected from the group consisting of a monocarboxylic acid and a monohydric alcohol. Examples of the polyol constituting the complex ester can be the same as those constituting the polyol ester described above. The polycarboxylic acid constituting the complex ester can be a dicarboxylic acid. The dicarboxylic acid can have 2 or more carbon atoms, preferably 4 or more, 12 or less, and preferably 10 or less. Examples of polycarboxylic acids include succinic acid, adipic acid, azelaic acid, sebacic acid, etc.

[0077] The monocarboxylic acid constituting the complex ester can be a fatty acid. Examples of fatty acids can be the same as those constituting the polyol esters described above. The monohydric alcohol constituting the complex ester can have 2 or more carbon atoms, preferably 4 or more, preferably 20 or less, preferably 10 or less. Examples of monohydric alcohols include ethanol, butanol, hexanol, octanol, nonanol, and decol.

[0078] API base oil classification is divided into: Group I (viscosity index above 80 and below 120, sulfur content above 0.03% by mass and / or saturation content below 90% by mass; solvent refined base oil), Group II (viscosity index above 80 and below 120, sulfur content below 0.03% by mass and saturation content above 90% by mass: hydrorefined base oil), Group III (viscosity index above 120, sulfur content below 0.03% by mass and saturation content above 90% by mass: hydrocracking / hydroisomerization oil), Group IV (polyalphaolefin base oil), and Group V (base oil not belonging to any of Groups I to IV).

[0079] The base oil may contain at least one of the groups consisting of base oils classified into any of these classes as a main component. The aforementioned group may preferably consist of base oils classified into any of Group II, III, IV, and V; may consist of base oils classified into any of Group III, IV, and V; or may consist of base oils classified into Group III or IV.

[0080] As these base oils, base oils with a saturated content of 90% or more by mass, preferably 94% or more by mass, 97% or more by mass, or 99% or more by mass, and an aromatic content of 10% or less by mass, preferably 6% or less by mass, 3% or less by mass, or 1% or less by mass, can be used as the main components. %C P For 60 and above, 70 and above, 75 and above or 80 and above, %C N For 40 or below, 30 or below, or 25 or below, %C A The main component is a base oil with a content of 5% or less, 3% or less, 1% or less, or 0.1% or less. It should be noted that the %C mentioned here refers to...P %C N %C A (Total 100) refers to the weight ratio of alkane carbon content, cycloalkanes carbon content, and aromatic carbon content to total carbon content (calculated according to ASTM D 3238). The viscosity index of these base oils is preferably 80 or higher, but can be 90 or higher, 100 or higher, 120 or higher, 130 or higher, 140 or higher, or 150 or higher. Examples of base oils classified as Group V include aromatic hydrocarbon base oils such as alkylbenzenes and alkylnaphthalenes, and oxygen-containing base oils such as esters and ethers, with ester-based or ether-based base oils being preferred. The viscosity index of at least one oxygen-containing base oil selected from ester-based and ether-based base oils is preferably 50 or higher, or 80 or higher, but can be 90 or higher, 100 or higher, 120 or higher, 130 or higher, 140 or higher, or 150 or higher.

[0081] The kinematic viscosity of the base oil at 40°C can be 3 mm. 2 / s or more, 4mm 2 / s or more or 5mm 2 / s or higher, can be 500mm 2 / s or less, 300mm 2 / s or less or 100mm 2 / s or less. The kinematic viscosity of the base oil at 100°C can be 1 mm. 2 / s or more or 2mm 2 / s or higher, can be 100mm 2 / s or less or 50mm 2 / s or less. The kinematic viscosity in this specification refers to the kinematic viscosity measured according to JIS K2283:2000.

[0082] The base oil content, based on the total amount of lubricating oil, can be 50% or more by mass, 60% or more by mass, 70% or more by mass, 80% or more by mass, or 90% or more by mass.

[0083] Lubricating oils may contain only base oils or may contain additives in addition to base oils. Examples of additives include ashless friction modifiers (details below), anti-wear agents, extreme pressure agents, metal friction modifiers, antioxidants, acid scavengers, metal deactivators, viscosity index improvers, pour point depressants, detergent dispersants, defoamers, and thickeners.

[0084] The total content of additives, based on the total amount of lubricating oil, can be more than 0.1% by mass, more than 0.5% by mass, or more than 1% by mass, or less than 40% by mass, less than 20% by mass, less than 10% by mass, or less than 5% by mass.

[0085] In the oil / seal lubrication system described above, at least one of the sealing member and the lubricating oil contains an ashless friction modifier. That is, in one embodiment, the sealing member contains an ashless friction modifier, while the lubricating oil may not contain one. In another embodiment, the lubricating oil contains an ashless friction modifier, while the sealing member may not contain one. In yet another embodiment, both the sealing member and the lubricating oil may contain an ashless friction modifier. From the viewpoint of achieving a particularly significant low-friction effect, it is preferable that both the sealing member and the lubricating oil contain an ashless friction modifier. When both the sealing member and the lubricating oil contain an ashless friction modifier, the ashless friction modifier in the sealing member and the ashless friction modifier in the lubricating oil may be the same or different from each other.

[0086] Ashless friction modifiers can be, for example, at least one selected from the group consisting of fatty acid ester compounds, phosphorus compounds, ether compounds, alcohol compounds, amide compounds, amine compounds, imide compounds, sulfur compounds, and phosphorus-sulfur compounds. From the viewpoint of achieving further low friction, ashless friction modifiers are preferably at least one selected from the group consisting of fatty acid ester compounds, phosphorus compounds, amide compounds, amine compounds, imide compounds, sulfur compounds, and phosphorus-sulfur compounds. These friction modifiers can be compounds having a hydrocarbon group and a polar group. Examples of hydrocarbon groups include chain hydrocarbon groups, aromatic hydrocarbon groups, and alicyclic hydrocarbon groups. The number of carbon atoms in the hydrocarbon group can be 2 or more, 400 or less, 200 or less, or 40 or less. The hydrocarbon group can be a saturated hydrocarbon group or an unsaturated hydrocarbon group. Examples of polar groups include ester groups, carboxyl groups, amino groups, amide groups, imide groups, and phosphate groups. These polar groups can be adsorbed onto the surface of inorganic filler materials.

[0087] When both the sealing component and the lubricating oil contain ashless friction modifiers, the combination of the ashless friction modifier in the sealing component and the ashless friction modifier in the lubricating oil can be the combinations C1 to C81 shown in Table 1 below.

[0088] [Table 1]

[0089]

[0090] In the above combination, preferably at least one of the ashless friction modifier in the sealing component and the ashless friction modifier in the lubricating oil is a combination of fatty acid ester compounds (C1~C9, C10, C19, C28, C37, C46, ​​C55, C64, C73), more preferably both the ashless friction modifier in the sealing component and the ashless friction modifier in the lubricating oil are a combination of fatty acid ester compounds (C1).

[0091] The fatty acid ester compound is selected from at least one ester of fatty acids and monohydric or polyhydric alcohols, preferably an ester of fatty acids and polyhydric alcohols. The fatty acid ester compound has a hydrocarbon group derived from a fatty acid or alcohol. This hydrocarbon group may have 2 or more carbon atoms, preferably 6 or more or 12 or more, but may have 40 or fewer, preferably 20 or fewer or 18 or fewer.

[0092] In one embodiment, the fatty acid ester compound may have the aforementioned hydrocarbon group, ester group, and hydroxyl group (i.e., it may be a partial ester of fatty acid and polyol). The fatty acid ester compound may contain more than 10% by mass of a partial ester of fatty acid and polyol, and may be included as a main component (e.g., more than 50% by mass, preferably more than 60% by mass, more than 70% by mass, more than 80% by mass, or more than 90% by mass, less than 100% by mass).

[0093] The fatty acids constituting fatty acid ester compounds may have 2 or more carbon atoms, preferably 6 or more, but may have 30 or fewer, preferably 20 or fewer. More preferably, the fatty acids may comprise saturated or unsaturated fatty acids with 12 or more and 18 or fewer carbon atoms, and may comprise at least one selected from the group consisting of lauric acid, myristic acid, palmitic acid, stearic acid, and oleic acid.

[0094] The monohydric alcohol constituting the fatty acid ester compound can be an aliphatic alcohol. The aliphatic alcohol can have 2 or more carbon atoms, preferably 6 or more, but less than 30, preferably less than 20. More preferably, the monohydric alcohol can comprise a saturated or unsaturated aliphatic alcohol with 12 or more and 18 or less carbon atoms, and can comprise at least one selected from the group consisting of lauryl alcohol, myristyl alcohol, palmitol, stearyl alcohol, and oleyl alcohol.

[0095] The polyol constituting the fatty acid ester compound may have 2 to 6 hydroxyl groups. The polyol may have 2 or more carbon atoms, preferably 3 or more, but may have 12 or fewer, preferably 6 or fewer. More preferably, the polyol comprises a polyol having 3 or more and 6 or fewer carbon atoms and 2, 3 or 4 hydroxyl groups, and may contain at least one selected from the group consisting of glycerol, sorbitol, neopentyl glycol, trimethylolpropane and pentaerythritol.

[0096] Specific examples of these fatty acid ester compounds include fatty acid monoesters such as oleyl alcohol oleate and stearyl stearate, which have hydrocarbon groups with 12 or more but less than 18 carbon atoms. Other specific examples of fatty acid ester compounds include polyol fatty acid esters such as glycerol fatty acid esters, sorbitan fatty acid esters, neopentyl glycol fatty acid esters, trimethylolpropane fatty acid esters, and pentaerythritol fatty acid esters, which have hydrocarbon groups with 12 or more but less than 18 carbon atoms. These polyol fatty acid esters can be partial esters; more specifically, they can be glycerol monooleate, sorbitan monooleate, trimethylolpropane decanoate (main components: monoester and diester), pentaerythritol oleate (main components: monoester, diester, and triester), etc. Other specific examples of fatty acid ester compounds include polymethyl methacrylates, which have hydrocarbon groups with 1 or more but less than 40 carbon atoms.

[0097] Phosphorus compounds are compounds containing phosphorus as a constituent element (excluding compounds containing sulfur as a constituent element). Examples of phosphorus compounds include phosphites, orthophosphates, amine salts of acidic phosphates, hydrogen phosphites, phosphonates, and hypophosphonates. Phosphorus compounds may contain a hydrocarbon group. The number of carbon atoms in the hydrocarbon group of phosphorus compounds can be 1 or more, 6 or more, or 12 or more, and can be 30 or less, 20 or less, or 18 or less.

[0098] The phosphorus compound is preferably at least one selected from the group consisting of amine salts of phosphites, orthophosphates, and acid phosphates.

[0099] Examples of phosphites include dialkyl phosphites, dienyl phosphites, diaryl phosphites, trialkyl phosphites, trienyl phosphites, and triaryl phosphites. The phosphite is preferably at least one selected from the group consisting of dienyl phosphites and diaryl phosphites.

[0100] Examples of alkyl groups in dialkyl phosphites and trialkyl phosphites include butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl. Examples of alkenyl groups in dienyl phosphites and trialkyl phosphites include oleyl. Examples of aryl groups in diaryl phosphites and triaryl phosphites include phenyl and tolyl.

[0101] Examples of orthophosphates include trialkyl phosphates, trienyl phosphates, and triaryl phosphates. Examples of alkyl groups in trialkyl phosphates include butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, decyl, tetradecyl, pentadecyl, hexadecyl, heptadecanyl, and octadecyl. Examples of alkenyl groups in trienyl phosphates include oleyl. Examples of aryl groups in triaryl phosphates include phenyl, tolyl, ethylphenyl, butylphenyl, and xylyl. Triaryl phosphates are preferred, and tricresyl phosphates are more preferred.

[0102] Examples of acidic phosphates among the amine salts of acidic phosphates include monoalkyl phosphates, monoalkenyl phosphates, dialkyl phosphates, and dienyl phosphates.

[0103] Examples of alkyl groups in monoalkyl and dialkyl phosphate esters include butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecanyl, and octadecyl. Examples of alkenyl groups in monoalkenyl and dienyl phosphate esters include oleyl.

[0104] Examples of amines in the amine salts of acidic phosphate esters include monoalkylamines, dialkylamines, and trialkylamines. Examples of alkyl groups in these amines include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, and octyl.

[0105] Ether compounds are compounds having both a hydrocarbon group and an ether group. The hydrocarbon group can have 1 or more, 6 or more, or 12 or more carbon atoms, and can have 30 or fewer, 20 or fewer, or 18 or fewer carbon atoms. Examples of ether compounds include etherifications of polyols having a hydrocarbon group with 6 or more and 18 fewer carbon atoms, such as glyceryl oleyl ether, glyceryl stearyl ether, glyceryl 2-ethylhexyl ether, and glyceryl hexyl ether; and etherifications of monohydric alcohols having a hydrocarbon group with 6 or more and 18 fewer carbon atoms, such as dioctyl ether and diphenyl ether.

[0106] Alcohols are compounds containing a hydrocarbon group and a hydroxyl group. The hydrocarbon group can have 1 or more, 6 or more, or 12 or more carbon atoms, and can have 30 or fewer, 20 or fewer, or 18 or fewer carbon atoms. Examples of alcohols include oleyl alcohol, lauryl alcohol, decanol, stearyl alcohol, cyclohexanol, and phenol, which have a hydrocarbon group with 6 or more and 18 or fewer carbon atoms.

[0107] Examples of amide compounds include oleylsarcosine, fatty acid amides, oleyl oleate monoamide, stearyl oleate monoamide, and other fatty acid monoamides, as well as ethylene distearate diamide and ethylene dioleate diamide, and other fatty acid diamides. The hydrocarbon group in amide compounds can have 1 or more, 6 or more, or 12 or more carbon atoms, and can have 30 or fewer, 20 or fewer, or 18 or fewer carbon atoms.

[0108] Examples of amine compounds include alkylamines, alkenylamines, or their alkylene oxide adducts, alkanolamines, etc. Alkylamines can be monoalkylamines, dialkylamines, or trialkylamines. Alkenylamines can be monoalkenylamines, dienylamines, or trialkenylamines.

[0109] The hydrocarbon group in alkylamines or alkenylamines can have 1 or more, 6 or more, or 12 or more carbon atoms, and can have 30 or less, 20 or less, or 18 or less. Examples of alkylamines include stearylamine. Examples of alkenylamines include oleylamine. Examples of alkanolamines include N,N-bis(2-hydroxyethyl)stearylamine and oleylalkenyl diethanolamine. Examples of alkyl oxide adducts include ethylene oxide adducts of alkyl or alkenylamines.

[0110] Examples of imide compounds include alkyl or alkenyl succinimides and their boron adducts. Specific examples include succinimides with a hydrocarbon group having 30 or fewer carbon atoms, such as alkenyl succinimides, and boron adducts of high-molecular-weight poly(iso)butenyl succinimides and their boric acid-modified derivatives. The hydrocarbon group in the imide compound can have 1 or more, 6 or more, or 12 or more carbon atoms, and can have 30 or fewer, 20 or fewer, or 18 or fewer carbon atoms. Furthermore, the average number of carbon atoms in the poly(iso)butenyl succinimide can be 40 or more, 60 or more, or 80 or more, and can have 400 or fewer, 200 or fewer, or 150 or fewer carbon atoms.

[0111] Chalcogenides are compounds that contain sulfur as a constituent element (excluding compounds containing phosphorus as a constituent element). Examples of chalcogenides include sulfurized alkenes, sulfurized oils and fats, sulfurized esters, thiazoles, thiadiazoles, dithiocarbamates, and thioethers. Chalcogenides may contain a hydrocarbon group. The number of carbon atoms in the hydrocarbon group of chalcogenides can be 1 or more, 6 or more, 30 or less, 20 or less, or 18 or less.

[0112] The sulfur-based compounds are preferably thioethers. Thioethers can be monothioethers or polythioethers. Examples of thioethers include dialkyl thioethers. Dialkyl thioethers are preferably dialkyl polythioethers. The alkyl group in the dialkyl thioether (dialkyl polythioether) can have 1 or more carbon atoms, preferably 4 or more or 6 or more, and can have 12 or less, preferably 10 or less. The sulfur-based compounds can be dithiocarbamates. Specific examples include dialkyl dithiocarbamates. The alkyl group in the dialkyl dithiocarbamate can have 1 or more carbon atoms, preferably 4 or more or 6 or more, and can have 12 or less, preferably 10 or less.

[0113] Phosphorus-sulfur compounds are compounds containing phosphorus and sulfur as constituent elements. Examples of phosphorus-sulfur compounds include thiophosphates or their derivatives having 1 to 3, preferably 1 or 2, sulfur atoms. The number of carbon atoms in the hydrocarbon group of a phosphorus-sulfur compound can be 1 or more, 4 or more, or 6 or more, and can be 30 or less, 20 or less, or 18 or less. Examples of phosphorus-sulfur compounds include thiophosphates, triphenylthiophosphates, and dialkyl dithiophosphoric acids or their esters, such as 3-diisobutoxythiophosphonothio-2-methylpropionic acid or its esters.

[0114] The content of friction modifier contained in the sealing member 5 is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 1 part by mass or more, more preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less, relative to 100 parts by mass of the rubber component in the sealing member 5.

[0115] The content of friction modifier in lubricating oil, based on the total amount of lubricating oil, can be more than 0.01% by mass, more than 0.05% by mass, or more than 0.1% by mass, or less than 10% by mass, less than 5% by mass, or less than 3% by mass.

[0116] By using the sealing components and lubricating oil described above, low friction can be achieved. For example, the coefficient of friction measured using the sealing components and lubricating oil via an MTM testing machine can be 0.050 or less, 0.048 or less, 0.046 or less, 0.044 or less, 0.042 or less, or 0.040 or less. This coefficient of friction is determined by the friction coefficient measurement method described in the examples.

[0117] Example

[0118] The present invention will now be described in more detail based on embodiments, but the present invention is not limited to the embodiments.

[0119] (Fabrication of sealing component S1)

[0120] Using FKM (fluororubber, Solvay's Tecnoflon (registered trademark) P757) as the rubber component, relative to 100 parts by weight of FKM, 75 parts by weight of iron oxide (III) (RESINO COLOR INDUSTRY CO.,LTD.'s Brown #601) as an inorganic filler, and 5 parts by weight of glyceryl monooleate as an ashless friction modifier, the mixture was kneaded using a kneader and a two-roll mill, and molded at 180°C for 6 minutes to produce a 40×40×2mm sealing component S1.

[0121] (Fabrication of sealing component S2)

[0122] No friction modifier is used. Otherwise, the sealing member S2 is made in the same manner as the sealing member S1.

[0123] (Fabrication of sealing component S3)

[0124] Using wollastonite (Wolllastnite 1250 manufactured by IMERYS) instead of iron oxide (III), the sealing component S3 is made in the same manner as sealing component S2.

[0125] (Fabrication of sealing component S4)

[0126] Carbon black (acetylene black, manufactured by Denka Corporation, "DENKA BLACK") is used instead of iron oxide (III). Otherwise, sealing component S4 is manufactured in the same manner as sealing component S2.

[0127] (Fabrication of sealing component S5)

[0128] Seal member S5 is manufactured in the same manner as seal member S1, except that iron oxide (III) and glyceryl monooleate are not added.

[0129] (Lubricating oil L1)

[0130] The base oil (Group III mineral oil, kinematic viscosity at 40°C: 32 mm) 2 kinematic viscosity at 100℃ / s: 6mm 2 / s, viscosity index: 134, sulfur content: less than 1 ppm by mass, saturated content: more than 99.5% by mass, aromatic content: less than 0.5% by mass, %C P 79.2%, %C N 20.8, %C A Lubricating oil L1 was prepared by mixing 99% by mass of an ester compound (glyceryl monooleate) as an ashless friction modifier with 1% by mass of an ester compound (glyceryl monooleate).

[0131] (Lubricating oil L2)

[0132] Use only the same base oil as lubricating oil L1 (Group III mineral oil, kinematic viscosity at 40°C: 32 mm). 2 kinematic viscosity at 100℃ / s: 6mm 2 / s, viscosity index: 134, sulfur content: less than 1 ppm by mass, saturated content: more than 99.5% by mass, aromatic content: less than 0.5% by mass, %C P 79.2%, %C N 20.8, %C A :0.0) as lubricating oil L2.

[0133] (Lubricating oil L3)

[0134] A phosphorus-based compound (an amine salt of an acidic phosphate oleyl ester) was used instead of an ester-based compound as an ashless friction modifier. Otherwise, lubricating oil L3 was prepared in the same manner as lubricating oil L1.

[0135] (Lubricating oil L4)

[0136] Ether compounds (glyceryl oil alkenyl ether) were used instead of ester compounds as ashless friction modifiers. Otherwise, lubricating oil L4 was prepared in the same manner as lubricating oil L1.

[0137] (Lubricating oil L5)

[0138] Alcohol-based compounds (oleyl alcohol) are used instead of ester-based compounds as ashless friction modifiers. Otherwise, lubricating oil L5 is prepared in the same manner as lubricating oil L1.

[0139] (Lubricating oil L6)

[0140] Alkamide compounds (oleoylsarcosine) were used instead of ester compounds as ashless friction modifiers. Otherwise, lubricating oil L6 was prepared in the same manner as lubricating oil L1.

[0141] In Examples 1-13 and Comparative Examples 1-2, one of the sealing components S1-S4 and lubricating oils L1-L6 was selected, and the coefficient of friction was measured for the combinations shown in Tables 2 and 3.

[0142] (Determination of the coefficient of friction)

[0143] The coefficient of friction was determined using an MTM (MiniTraction Machine) manufactured by PCS Instruments under the following conditions.

[0144] • Ball: 1 / 2-inch steel ball

[0145] • Disc: Sealing component (40×40×2mm)

[0146] • Load: 10N

[0147] • Slip rate: 200% (complete slip)

[0148] Average speed: 0.1 m / s

[0149] Oil temperature: 25℃

[0150] The friction coefficient was measured three times for each combination of sealing component and lubricating oil, and the average value of the friction coefficient obtained from the three measurements was calculated. The results are shown in Tables 2 and 3.

[0151] [Table 2]

[0152]

[0153] [Table 3]

[0154]

[0155] It should be noted that in Tables 2 and 3, "(with)" means that it contains ashless friction modifiers, and "(without)" means that it does not contain ashless friction modifiers. The same applies to Table 4, which will be discussed later.

[0156] In addition, in Examples 14-16 and Comparative Example 5, one of each of the sealing components S1-S2, S5 and the lubricating oils L7-L8 described above was selected, and the coefficient of friction was measured in the same manner as above for the combinations shown in Table 4. The results are shown in Table 4.

[0157] (Lubricating oil L7)

[0158] The base oil (a type V ester, trimethylolpropane trioleate), with a kinematic viscosity of 47.7 mm at 40°C. 2 Kinematic viscosity at 100℃ / s: 9.5mm 2 Lubricating oil L7 is prepared by mixing 99% by mass of a ester compound (glycerol monooleate ester) as an ashless friction modifier with a viscosity index of 189 and a sulfur content of less than 1 ppm by mass.

[0159] (Lubricating oil L8)

[0160] Using only the same base oil as lubricant L7 (Class V ester (trimethylolpropane trioleate), kinematic viscosity at 40°C: 47.7 mm). 2 Kinematic viscosity at 100℃ / s: 9.5mm 2 / s, viscosity index: 189, sulfur content: less than 1 ppm by mass) as lubricating oil L8.

[0161] [Table 4]

[0162]

[0163] Explanation of reference numerals in the attached figures

[0164] 1… Oil / sealing lubrication system, 2… Housing, 3… Rotating shaft (sliding member), 4… Reinforcing ring, 4a… Cylindrical part, 4b… Inward flange part, 5… Sealing member, 6… Outer peripheral seal, 7… Sealing lip, 8… Dustproof lip, 9… Sealing object side inclined surface, 10… Sliding surface, 11… Atmospheric side inclined surface, 14… Clamping spring, A… Atmospheric side, O… Sealing object side.

Claims

1. An oil / sealing lubrication system, comprising: Sealing components; and A sliding member that moves relative to the sealing member and contacts the sealing member via lubricating oil. The sealing component contains an inorganic filler material. At least one of the sealing component and the lubricating oil contains an ashless friction modifier.

2. The oil / seal lubrication system according to claim 1, wherein, Both the sealing component and the lubricating oil contain the ashless friction modifier.

3. The oil / seal lubrication system according to claim 1 or 2, wherein, The inorganic filler material is at least one selected from the group consisting of carbon black, metal oxides, metal hydroxides, and silicate minerals.

4. The oil / seal lubrication system according to claim 1 or 2, wherein, The ashless friction modifier is selected from at least one group consisting of fatty acid ester compounds, phosphorus compounds, ether compounds, alcohol compounds, amide compounds, amine compounds, imide compounds, sulfur compounds, and phosphorus-sulfur compounds.

5. The oil / seal lubrication system according to claim 2, wherein, The friction modifier in the sealing component and the friction modifier in the lubricating oil are fatty acid ester compounds.

6. The oil / seal lubrication system according to claim 5, wherein, The fatty acid ester compounds contain compounds having hydrocarbon groups, ester groups, and hydroxyl groups.

7. The oil / seal lubrication system according to claim 1 or 2, wherein, The lubricating oil contains at least one base oil selected from the group consisting of base oils classified as any one of the API base oil categories I, II, III, IV and V.

8. The oil / seal lubrication system according to claim 1 or 2, wherein, The lubricating oil contains a base oil with a viscosity index of 80 or higher.

9. The oil / seal lubrication system according to claim 1 or 2, wherein, The lubricating oil contains %C P For 60 and above, %C A It is a base oil with a strength of 5 or less.

10. The oil / seal lubrication system according to claim 1 or 2, wherein, The lubricating oil contains oxygen-containing base oil.

11. The oil / seal lubrication system according to claim 1 or 2, wherein, The coefficient of friction measured using the sealing component and the lubricating oil by an MTM testing machine is below 0.050.

Images