WO2022045233A1 - グリース組成物および転がり軸受 - Google Patents

グリース組成物および転がり軸受 Download PDF

Info

Publication number
WO2022045233A1
WO2022045233A1 PCT/JP2021/031288 JP2021031288W WO2022045233A1 WO 2022045233 A1 WO2022045233 A1 WO 2022045233A1 JP 2021031288 W JP2021031288 W JP 2021031288W WO 2022045233 A1 WO2022045233 A1 WO 2022045233A1
Authority
WO
WIPO (PCT)
Prior art keywords
grease composition
oil
thickener
bearing
base oil
Prior art date
Application number
PCT/JP2021/031288
Other languages
English (en)
French (fr)
Japanese (ja)
Inventor
隆之 川村
新樹 田中
Original Assignee
Ntn株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ntn株式会社 filed Critical Ntn株式会社
Priority to CN202180050685.9A priority Critical patent/CN115867631A/zh
Publication of WO2022045233A1 publication Critical patent/WO2022045233A1/ja

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M105/00—Lubricating compositions characterised by the base-material being a non-macromolecular organic compound
    • C10M105/08—Lubricating compositions characterised by the base-material being a non-macromolecular organic compound containing oxygen
    • C10M105/18—Ethers, e.g. epoxides
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M115/00—Lubricating compositions characterised by the thickener being a non-macromolecular organic compound other than a carboxylic acid or salt thereof
    • C10M115/08—Lubricating compositions characterised by the thickener being a non-macromolecular organic compound other than a carboxylic acid or salt thereof containing nitrogen
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M129/00—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing oxygen
    • C10M129/02—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing oxygen having a carbon chain of less than 30 atoms
    • C10M129/26—Carboxylic acids; Salts thereof
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M133/00—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing nitrogen
    • C10M133/02—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing nitrogen having a carbon chain of less than 30 atoms
    • C10M133/04—Amines, e.g. polyalkylene polyamines; Quaternary amines
    • C10M133/12—Amines, e.g. polyalkylene polyamines; Quaternary amines having amino groups bound to a carbon atom of a six-membered aromatic ring
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M169/00—Lubricating compositions characterised by containing as components a mixture of at least two types of ingredient selected from base-materials, thickeners or additives, covered by the preceding groups, each of these compounds being essential
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M169/00—Lubricating compositions characterised by containing as components a mixture of at least two types of ingredient selected from base-materials, thickeners or additives, covered by the preceding groups, each of these compounds being essential
    • C10M169/02—Mixtures of base-materials and thickeners
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C19/00—Bearings with rolling contact, for exclusively rotary movement
    • F16C19/02—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows
    • F16C19/04—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for radial load mainly
    • F16C19/06—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for radial load mainly with a single row or balls
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/72—Sealings
    • F16C33/76—Sealings of ball or roller bearings
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K5/00—Casings; Enclosures; Supports
    • H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
    • H02K5/16—Means for supporting bearings, e.g. insulating supports or means for fitting bearings in the bearing-shields
    • H02K5/173—Means for supporting bearings, e.g. insulating supports or means for fitting bearings in the bearing-shields using bearings with rolling contact, e.g. ball bearings
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M107/00—Lubricating compositions characterised by the base-material being a macromolecular compound
    • C10M107/02—Hydrocarbon polymers; Hydrocarbon polymers modified by oxidation
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2010/00—Metal present as such or in compounds
    • C10N2010/02—Groups 1 or 11
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2010/00—Metal present as such or in compounds
    • C10N2010/04—Groups 2 or 12
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2020/00—Specified physical or chemical properties or characteristics, i.e. function, of component of lubricating compositions
    • C10N2020/01—Physico-chemical properties
    • C10N2020/02—Viscosity; Viscosity index
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
    • C10N2030/06—Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2040/00—Specified use or application for which the lubricating composition is intended
    • C10N2040/02—Bearings
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2050/00—Form in which the lubricant is applied to the material being lubricated
    • C10N2050/10—Semi-solids; greasy

Definitions

  • the present invention relates to a grease composition and a rolling bearing in which the grease composition is encapsulated, and more particularly to a grease composition used for a rolling bearing for a rotary electric machine such as a servomotor or an encoder, and a rolling bearing thereof.
  • Servo motors are equipped with detectors such as position and speed, and are capable of highly accurate positioning and fine-tuned rotation speed control, so demand is increasing mainly for machine tools and robot applications.
  • servomotors for robots are often used to drive joints, and in order to increase the axial speed and acceleration / deceleration of joints, small size and high output are required.
  • a detector and brake are placed near the rolling bearing to reduce the size. However, if some droplets of grease inside the bearing adhere to the detector and brake, the detection accuracy and braking performance will deteriorate. Is required to have low dust generation.
  • Dust is generated when a part of the grease evaporates or scatters due to heat generated by the rotation of the rolling bearing and the pressure rise inside the bearing, and is discharged to the outside of the bearing.
  • it is effective to increase the viscosity of the base oil of the grease to increase the surface tension and to reduce the amount of the base oil in the grease.
  • the supply (wraparound) of the base oil to the rolling surface or the sliding surface tends to be insufficient, which may lead to excessive temperature rise of the bearing, rough surface of the rolling surface or the sliding surface, and damage such as wear.
  • Patent Document 1 a base oil having a kinematic viscosity at 40 ° C. of 30 mm 2 / s to 180 mm 2 / s and containing at least one selected from synthetic hydrocarbon oils and ether oils and urea compounds.
  • a grease composition containing 0.1 to 1% by weight of the total amount of grease and containing an additive composed of only non-metal elements has been proposed.
  • the rolling bearing arranged in the vicinity of the encoder is made of at least one selected from synthetic hydrocarbon oil and ether oil, and It is described that a grease composition containing a base oil having a kinematic viscosity at 40 ° C. of 80 mm 2 / s to 120 mm 2 / s is enclosed.
  • Patent Document 1 is for a rolling apparatus used in a clean room such as a semiconductor manufacturing facility, and dust generation and durability at high temperatures have not been investigated. There are concerns about this. Further, the grease composition described in Patent Document 2 is used for a bearing unit for a motor that rotates in the forward and reverse directions, and simply defining the base oil and its kinematic viscosity has wear resistance and grease life. It may be insufficient in terms of.
  • the present invention has been made in view of such circumstances, and a grease composition capable of achieving low dust generation while suppressing a decrease in wear resistance and life, and a rolling bearing in which the grease composition is enclosed are provided.
  • the purpose is to provide.
  • the grease composition of the present invention is a grease composition containing a base oil and a thickener, wherein the base oil contains a synthetic hydrocarbon oil and an ether oil and has a kinematic viscosity of 120 mm 2 / s or more at 40 ° C.
  • the thickener is an aliphatic grease compound and an alicyclic grease compound, and is 12 parts by mass to 15 parts by mass with respect to 100 parts by mass of the total amount of the base oil and the thickener.
  • the grease composition contained above is characterized in that it has a mixing consistency of 200 to 240 as measured in accordance with JIS K 2220 and comprises a solid organic acid metal salt at 20 ° C.
  • the organic acid metal salt is characterized by being a sodium salt or a calcium salt. Further, the organic acid metal salt is a metal salt of an organic carboxylic acid having 2 to 18 carbon atoms, and the grease composition is characterized by not containing an additive containing sulfur and phosphorus in the molecular structure.
  • the grease composition further contains an amine-based antioxidant, and the amine-based antioxidant is N-phenyl-N'-isopropyl-p-phenylenediamine (PIPA).
  • PIPA N-phenyl-N'-isopropyl-p-phenylenediamine
  • the rolling bearing of the present invention includes an inner ring, an outer ring, a plurality of rolling elements interposed between the inner ring and the outer ring, seal members provided at openings at both ends of the inner ring and the outer ring in the axial direction, and an inner space of the bearing. It is a rolling bearing having a grease composition enclosed in, and is characterized in that the grease composition is the grease composition of the present invention.
  • the sealing member is made of nitrile rubber containing a trimellitic acid ester-based plasticizer.
  • the rolling bearing is characterized by being a bearing for rotary electric machines.
  • the base oil is a mixed oil containing a synthetic hydrocarbon oil and an ether oil and the kinematic viscosity at 40 ° C. is 120 mm 2 / s or more
  • the thickener is an aliphatic diurea compound and a fat.
  • It is a cyclic grease compound, contains 12 parts by mass to 15 parts by mass with respect to 100 parts by mass of the total amount of the base oil and the thickener, has a mixing consistency of 200 to 240, and is a solid organic acid at 20 ° C. Since it contains a metal salt, low dust generation can be realized while suppressing deterioration of wear resistance and life. Specifically, by adding a solid organic acid metal salt at 20 ° C.
  • the surface tension of the base oil is not affected and the base oil is used. It is considered that the organic acid metal salt can be melted and the steel surface can be protected as an extreme pressure agent when the supply of the organic acid metal is insufficient and wear is a concern.
  • the rolling bearing of the present invention is suitable for a bearing used in a rotary electric machine such as a servomotor, and the rotary electric machine is miniaturized and has a high height. It can contribute to higher output and lead to higher functionality.
  • the sealing member is formed of nitrile rubber containing a trimellitic acid ester-based plasticizer
  • the use of a low-volatile trimellitic acid ester-based plasticizer as the plasticizer suppresses the evaporation of the plasticizer itself. Therefore, low dust generation as a bearing can be further improved.
  • the grease composition of the present invention comprises a base oil having a predetermined kinematic viscosity, a predetermined thickener, and an additive, and the additive comprises a solid organic acid metal salt at 20 ° C. There is.
  • the base oil used in the grease composition of the present invention is a mixed oil containing synthetic hydrocarbon oil and ether oil and having a kinematic viscosity of 120 mm 2 / s or more at 40 ° C.
  • This kinematic viscosity is the kinematic viscosity of the mixed oil, preferably 120 mm 2 / s to 160 mm 2 / s at 40 ° C., and more preferably 125 mm 2 / s to 140 mm 2 / s.
  • PAO oil poly- ⁇ -olefin oil
  • PAO oils are ⁇ -olefins or mixtures of isomerized ⁇ -olefin oligomers or polymers.
  • Specific examples of the ⁇ -olefin include 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1 -Nonadecene, 1-eicosene, 1-dodecene, 1-tetradodecene and the like are mentioned, and a mixture thereof is usually used.
  • the ether oil examples include polyphenyl ether oil, alkyl diphenyl ether oil, alkyl triphenyl ether oil, and alkyl tetraphenyl ether oil.
  • alkyl diphenyl ether oil is preferable, and alkyl diphenyl ether oil is more preferably contained in an amount of 50% by mass or more of the total base oil (mixed oil) from the viewpoint of durability at high temperatures.
  • the alkyl diphenyl ether oil include monoalkyl diphenyl ether oil, dialkyl diphenyl ether oil, and polyalkyl diphenyl ether oil.
  • the base oil used in the present invention may be a mixed oil containing only synthetic hydrocarbon oil and ether oil, or may be a mixed oil to which other oils are added.
  • the other oil any oil usually used for rolling bearings can be used without particular limitation.
  • paraffin-based mineral oil, mineral oil such as naphthen-based mineral oil, ester oil, silicone oil, fluorine oil and the like can be mentioned.
  • the thickener used in the grease composition of the present invention is a mixture of an aliphatic diurea compound and an alicyclic diurea compound.
  • This thickener is a urea compound obtained by reacting a diisocyanate component with an aliphatic monoamine and an alicyclic monoamine.
  • the aliphatic diurea compound is obtained from an aliphatic monoamine as a monoamine component and a diisocyanate component
  • the alicyclic diurea compound is obtained from an alicyclic monoamine and a diisocyanate component as a monoamine component.
  • Examples of the diisocyanate component include phenylenediocyanate, tolylene diisocyanate, diphenyl diisocyanate, diphenylmethane diisocyanate, octadecane diisocyanate, decane diisocyanate, and hexane diisocyanate.
  • Examples of the aliphatic monoamine include hexylamine, octylamine, dodecylamine, hexadecylamine, octadecylamine, stearylamine, and oleylamine.
  • Examples of the alicyclic monoamine include cyclohexylamine.
  • the content of the aliphatic diurea compound in the thickener used in the present invention is preferably higher than the content of the alicyclic diurea compound.
  • Base grease can be obtained by blending a diurea compound as a thickener in the base oil.
  • the base grease containing a diurea compound as a thickener is prepared by reacting a diisocyanate component and a monoamine component in a base oil.
  • the thickener is contained in an amount of 12 parts by mass to 15 parts by mass with respect to 100 parts by mass of the total amount of the base oil and the thickener.
  • the organic acid metal salt used in the grease composition of the present invention is an organic carboxylic acid, an organic sulfonic acid such as alkylbenzene sulfonic acid, an organic sulfuric acid such as alkyl sulfate, an organic phosphonic acid such as alkylphosphonic acid, or an organic phosphinic acid such as alkylphosphinic acid.
  • the organic acid metal salt may be solid at 20 ° C., that is, the melting point may exceed 20 ° C., and the organic acid or metal ion constituting the organic acid metal salt can be appropriately selected.
  • the melting point of the organic acid metal salt is preferably 100 ° C. or higher, more preferably 150 ° C. or higher.
  • any metal that can form a salt with the above organic acid can be used, and lithium, sodium, potassium, magnesium, calcium, barium, zinc, aluminum and the like can be used.
  • the metal salt is preferably a sodium salt or a calcium salt, and more preferably a sodium salt.
  • the organic acid constituting the organic acid metal salt has a halogen group, a hydroxyl group, an amino group, an alkyl group, an alkoxy group, an epoxy group or other substituents on an aliphatic group or an aromatic group in the molecular structure. May be good. Further, it is preferable that the organic acid does not contain a sulfur atom and a phosphorus atom in the molecular structure, and the constituent atom is an atom selected from a carbon atom, a hydrogen atom, a nitrogen atom and an oxygen atom. preferable.
  • organic acids examples include acetic acid, propionic acid, butyric acid, hexane acid, lauric acid, myristic acid, palmitic acid, stearic acid, 12-hirodoxystearic acid, oleic acid, linoleic acid and the like having 2 to 2 carbon atoms.
  • organic carboxylic acids examples include 18 organic carboxylic acids, of which organic carboxylic acids having 10 to 18 carbon atoms are preferable, and linear organic carboxylic acids having no substituent are more preferable.
  • organic acid metal salt used in the present invention specifically, sodium acetate (melting point 324 ° C.), calcium acetate (melting point 160 ° C.), sodium stearate (melting point 220 ° C.), calcium stearate (melting point 179 ° C.) and the like are used. be able to.
  • the blending amount of the organic acid metal salt in the grease composition is preferably 0.5 parts by mass to 5 parts by mass, and 0.5 parts by mass to 3 parts by mass with respect to 100 parts by mass of the total amount of the base oil and the thickener. Parts are more preferable, and 1 part by mass to 3 parts by mass are further preferable.
  • the grease composition of the present invention preferably further contains an antioxidant as an additive.
  • an antioxidant an amine-based antioxidant, a phenol-based antioxidant, a sulfur-based antioxidant and the like can be used, and among these, it is preferable to use an amine-based antioxidant, for example, phenyl-1-.
  • examples thereof include naphthylamine, diphenyl-p-phenylenediamine, dipyridylamine, phenothiazine, N, N'-diisopropyl-p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine, dialkyldiphenylamine (DDPA) and the like.
  • rust preventives and oily agents such as esters and alcohols can be added to the grease composition, if necessary.
  • a rust preventive agent in order to secure the rust preventive performance of the grease itself.
  • the rust preventive is not particularly limited, but an ester-based rust preventive is preferable.
  • the ester-based rust preventive agent include partial esters of polyhydric alcohols such as sorbitan, sorbitol, pentaerythritol, sucrose and glycerin with carboxylic acids such as oleic acid and lauric acid, and succinic acid half esters.
  • the blending amount of the ester-based rust inhibitor is more preferably 0.2 parts by mass to 0.6 parts by mass with respect to 100 parts by mass of the total amount of the base oil and the thickener.
  • the grease composition of the present invention does not contain an additive containing a phosphorus atom or a sulfur atom in the molecular structure.
  • an additive containing a phosphorus atom or a sulfur atom in the molecular structure.
  • the inclusion of these additives results in a decrease in the surface tension of the base oil, and as a result, the amount of dust generated tends to increase.
  • examples of such additives include phosphate esters such as tricresyl phosphate, subphosphate esters such as tricresyl phosphate, thiophosphate, thiophosphite, zinc alkyl dithiophosphate (ZnDTP), and alkyl dithiophosphates.
  • Extreme pressure agents such as molybdenum (MoDTP) and zinc dithiocarbamate (ZnDTC) can be mentioned.
  • the mixing consistency (JIS K 2220) of the grease composition of the present invention is in the range of 200 to 240. From the viewpoint of suppressing the amount of dust generated, the mixing consistency is preferably in the range of 200 to 220.
  • FIG. 1 is a cross-sectional view of a deep groove ball bearing.
  • an inner ring 2 having an inner ring raceway surface 2a on the outer peripheral surface and an outer ring 3 having an outer ring raceway surface 3a on the inner peripheral surface are arranged concentrically, and a plurality of rolling bearings 1 are arranged between the inner ring raceway surface 2a and the outer ring raceway surface 3a.
  • the rolling elements 4 are arranged.
  • the rolling element 4 is held by the cage 5.
  • the seal member 6 in FIG. 1 is a contact-type seal member in which the inner diameter lip contacts inside the seal groove.
  • the inner ring 2, the outer ring 3, and the rolling element 4 are made of an iron-based metal material, and the grease composition 7 is lubricated by interposing the raceway surface with the rolling element 4.
  • the iron-based metal material constituting the bearing member such as the inner ring 2, the outer ring 3, the rolling element 4, and the cage 5 is any material generally used as the bearing material, for example, high carbon chrome.
  • Bearing steel (SUJ1, SUJ2, SUJ3, SUJ4, SUJ5, etc .; JIS G4805), carburized steel (SCr420, SCM420, etc .; JIS G4053), stainless steel (SUS440C, etc .; JIS G4303), high-speed steel (M50, etc.) , Cold rolled steel and the like.
  • the sealing member 6 may be made of metal or a rubber molded body alone, or may be a composite of a rubber molded body and a metal plate, a plastic plate, or a ceramic plate. As shown in FIG. 1, a composite of a rubber molded body and a metal plate is preferable from the viewpoint of durability and ease of fixing.
  • nitrile rubber (NBR), acrylic rubber, silicone rubber, fluororubber and the like are used, and the rubber molded body contains a plasticizer.
  • the plasticizer can be appropriately selected from known plasticizers and used, but it is preferable to use an ester-based plasticizer.
  • the ester-based plasticizer include phthalate ester-based plasticizers such as di-n-octyl phthalate, di-2-ethylhexyl phthalate, and diisononyl phthalate, adipinate-based plasticizers, and trimellitic acid ester-based plasticizers.
  • ester compounds such as plasticizers and pyromellitic acid ester-based plasticizers.
  • the trimellitic acid ester-based plasticizer is more preferable from the viewpoint of suppressing the amount of dust generated.
  • the trimellitic acid ester-based plasticizer is represented by the following formula (1).
  • R 1 , R 2 , and R 3 may be the same or different. It is preferably the same. Further, R 1 , R 2 and R 3 are preferably aliphatic monohydric alcohol residues having 7 to 9 carbon atoms.
  • the aliphatic monohydric alcohol residue may be a linear alkyl group or a branched alkyl group. Specific examples thereof include tri-n-octyl trimellitic acid and tri-2-ethylhexyl trimellitic acid.
  • trimellitic acid ester-based plasticizer Leorube LTM, Leorube TM10 (manufactured by FMC) and the like can be used.
  • the rubber molded products may contain flame retardants, lubricants, stabilizers, fillers, foaming agents, antioxidants, processing aids, neutralizers, UV absorbers, and pigments, if necessary.
  • Antistatic agents, dispersants, thickeners, metal deterioration inhibitors, antifungal agents, flow modifiers and other known additives can also be blended.
  • a ball bearing is illustrated as a bearing, but the rolling bearing of the present invention includes a cylindrical roller bearing, a tapered roller bearing, a self-aligning roller bearing, a needle roller bearing, a thrust cylindrical roller bearing, a thrust tapered roller bearing, and a thrust needle. It can also be used as a roller bearing, thrust self-aligning roller bearing, etc.
  • the servomotor 11 has a rotor 12, a stator 13, a shaft 14, and an encoder 15 that reads the angle of the rotor 12 on the counterload side of the shaft 14.
  • the shaft 14 is supported by a rolling bearing 16 arranged on the load side and a rolling bearing 1 of the present invention arranged on the unload side.
  • the rolling bearing 1 of the present invention is arranged in the vicinity of the encoder 15, the amount of dust generated from the bearing is suppressed, so that the detection accuracy of the encoder 15 can be prevented from deteriorating.
  • the rolling bearing of the present invention is used not only for servomotors but also for other rotary electric machines that require low dust generation.
  • electric motors other than servomotors such as generators, spindle motors, stepping motors, and fan motors can be mentioned.
  • each content of the base oil, the thickener and the additive shows the content ratio (mass%) with respect to the base grease (base oil + thickener).
  • the grease compositions of Examples 1 to 8 in Table 1 contain only an organic acid metal salt and an amine-based antioxidant as additives. Dioctyldiphenylamine was used for DDPA in Tables 1 and 2. Further, 1) to 9) below in Table 1 are the same in Table 2.
  • Each grease composition was encapsulated in a deep groove ball bearing 6900 (inner diameter 10 mm ⁇ outer diameter 22 mm ⁇ width 6 mm) provided with a contact-type sealing member to prepare a test bearing.
  • NBR containing a phthalate ester-based plasticizer (di-2-ethylhexyl phthalate) was used as a plasticizer for the seal members other than Example 8, and trimellitic acid was used as a plasticizer for the seal members of Example 8.
  • NBR containing an ester plasticizer (Leolube LTM, manufactured by FMC, kinematic viscosity at 40 ° C. 53 mm 2 / s) was used.
  • the obtained test bearing was rotated on the inner ring at an atmospheric temperature of 120 ° C., 6000 min -1 , and 200 hours. Glass plates were placed at both ends in the axial direction of the test bearing, and the grease composition scattered from the bearing was attached.
  • the amount of dust generated was determined by subtracting the weight of the glass plate before the test from the weight of the glass plate after the test. Regarding the evaluation of the amount of dust generated, 3 mg or less is marked with a ⁇ mark, 3 mg or less is marked with a circle, 4 mg or more is marked with a ⁇ mark, and 6 mg or less is marked with a cross mark, and Table 1 and Table 2 indicate that the amount is larger than 6 mg.
  • Each grease composition was subjected to a wear test using a ball-on-disk type reciprocating tester.
  • Each grease composition is applied to a steel flat plate (20 mm square and 5 mm thick) type test piece, and one SUJ2 steel ball (7/16 inch) is pressed against it with a load of 98 N, and the amplitude is 0.47 mm and the frequency is 30 Hz. It was slid back and forth for 8 hours. The wear depth ( ⁇ m) of the steel plate after this test was measured.
  • ⁇ Grease life test> 1.8 g of each grease composition was encapsulated in a deep groove ball bearing 6204 (inner diameter 20 mm, outer diameter 47 mm, width 14 mm) to prepare a test bearing.
  • the obtained test bearing was rotated at a rotation speed of 10,000 min -1 under the conditions of an outer diameter portion temperature of the bearing outer ring of 180 ° C., an axial load of 67 N, and a radial load of 67 N, and the time until seizure was measured. ..
  • 300 hours or more is marked with ⁇
  • 230 hours or more and less than 300 hours is marked with ⁇
  • 150 hours or more and less than 230 hours is marked with ⁇
  • less than 150 hours is marked with ⁇ , which are shown in Tables 1 and 2.
  • the amount of dust generated in Example 8 was 2 mg or less, which was superior to the other test examples marked with ⁇ in terms of dust generation.
  • a base oil containing PAO oil and ether oil and having a predetermined kinematic viscosity a thickener containing an aliphatic diurea compound and an alicyclic diurea compound, and an organic acid metal salt.
  • the organic acid metal salt particularly contributes to the improvement of wear resistance and grease life.
  • Comparative Example 1, Comparative Example 4, and Comparative Example 10 to which ZnDTP was added as an additive had relatively good wear resistance and grease life, but resulted in an increase in the amount of dust generated.
  • a separate surface tension test in accordance with JIS K2241 revealed that the surface tension of PAO oil alone with a kinematic viscosity of 47 mm 2 / s at 40 ° C was 29.8 mN / m, whereas the PAO oil had a surface tension of 29.8 mN / m.
  • the surface tension of the test oil to which 2% by mass of ZnDTP was added was 26 mN / m.
  • the amount of dust generated is compared with the case where NBR containing a phthalate ester-based plasticizer is used (Example 3). Has decreased. It is considered that the trimellitic acid ester plasticizer has lower volatility (high boiling point) than the phthalate ester plasticizer, and as a result, the evaporation of the plasticizer itself is suppressed and the amount of dust generated is reduced. Be done. As described above, the heat-resistant NBR sealing member improves the low dust generation property.
  • the grease composition of the present invention is a combination of a predetermined base oil and a predetermined thickener, specifically, a base oil having excellent heat resistance and a high surface tension, a predetermined thickener, and low volatilization / release.
  • a solid organic acid metal salt at 20 ° C it does not affect the surface tension of the base oil, and when the supply of the base oil is insufficient and there is concern about wear, it is organic.
  • the acid metal salt melts and can protect the steel surface as an extreme pressure agent.
  • the grease composition of the present invention can realize low dust generation while suppressing deterioration of wear resistance and life, it is particularly suitable for rolling bearings for rotary electric machines such as servomotors and encoders, which require low dust generation. It can be suitably used.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Emergency Medicine (AREA)
  • Power Engineering (AREA)
  • Lubricants (AREA)
  • Rolling Contact Bearings (AREA)
  • Sealing Of Bearings (AREA)
  • Motor Or Generator Frames (AREA)
PCT/JP2021/031288 2020-08-28 2021-08-26 グリース組成物および転がり軸受 WO2022045233A1 (ja)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202180050685.9A CN115867631A (zh) 2020-08-28 2021-08-26 润滑脂组合物及滚动轴承

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2020-145104 2020-08-28
JP2020145104A JP2022039847A (ja) 2020-08-28 2020-08-28 グリース組成物および転がり軸受

Publications (1)

Publication Number Publication Date
WO2022045233A1 true WO2022045233A1 (ja) 2022-03-03

Family

ID=80353347

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2021/031288 WO2022045233A1 (ja) 2020-08-28 2021-08-26 グリース組成物および転がり軸受

Country Status (3)

Country Link
JP (2) JP2022039847A (zh)
CN (1) CN115867631A (zh)
WO (1) WO2022045233A1 (zh)

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11166191A (ja) * 1997-12-02 1999-06-22 Nippon Seiko Kk 転動装置
JP2000192973A (ja) * 1998-12-25 2000-07-11 Ntn Corp 低発塵性転がり軸受
JP2001226688A (ja) * 2000-02-17 2001-08-21 Ntn Corp 低発塵性潤滑グリースおよび転がり軸受並びに直動装置
JP2004124035A (ja) * 2002-08-02 2004-04-22 Ntn Corp グリース組成物および該グリース組成物封入軸受
JP2004224823A (ja) * 2003-01-20 2004-08-12 Nsk Ltd グリース組成物及び転動装置
JP2016222813A (ja) * 2015-05-29 2016-12-28 株式会社ジェイテクト グリース組成物およびその製造方法、ならびに当該グリース組成物が封入された転がり軸受
JP2017036385A (ja) * 2015-08-10 2017-02-16 Ntn株式会社 グリース組成物およびグリース封入転がり軸受
WO2021085100A1 (ja) * 2019-10-31 2021-05-06 ミネベアミツミ株式会社 低発塵高速回転用グリース組成物及びそれを封入した軸受
JP2021113250A (ja) * 2020-01-16 2021-08-05 シェルルブリカンツジャパン株式会社 グリース組成物

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000192070A (ja) * 1998-12-25 2000-07-11 Ntn Corp 低発塵性転がり軸受
EP1555448A3 (en) * 2004-01-14 2010-09-01 NTN Corporation Rolling bearing for use in vehicle
JP2005290278A (ja) * 2004-04-02 2005-10-20 Ntn Corp 耐防錆グリース組成物、グリース封入軸受および錆止め剤
JP2008274141A (ja) * 2007-04-27 2008-11-13 Nok Kluber Kk グリース組成物
JP2009204126A (ja) * 2008-02-28 2009-09-10 Nsk Ltd 一方向クラッチ内蔵型回転伝達装置

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11166191A (ja) * 1997-12-02 1999-06-22 Nippon Seiko Kk 転動装置
JP2000192973A (ja) * 1998-12-25 2000-07-11 Ntn Corp 低発塵性転がり軸受
JP2001226688A (ja) * 2000-02-17 2001-08-21 Ntn Corp 低発塵性潤滑グリースおよび転がり軸受並びに直動装置
JP2004124035A (ja) * 2002-08-02 2004-04-22 Ntn Corp グリース組成物および該グリース組成物封入軸受
JP2004224823A (ja) * 2003-01-20 2004-08-12 Nsk Ltd グリース組成物及び転動装置
JP2016222813A (ja) * 2015-05-29 2016-12-28 株式会社ジェイテクト グリース組成物およびその製造方法、ならびに当該グリース組成物が封入された転がり軸受
JP2017036385A (ja) * 2015-08-10 2017-02-16 Ntn株式会社 グリース組成物およびグリース封入転がり軸受
WO2021085100A1 (ja) * 2019-10-31 2021-05-06 ミネベアミツミ株式会社 低発塵高速回転用グリース組成物及びそれを封入した軸受
JP2021113250A (ja) * 2020-01-16 2021-08-05 シェルルブリカンツジャパン株式会社 グリース組成物

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
JAPAN TRIBOLOGY SOCIETY GREASE STUDY GROUP ED.: "Basics and applications of lubricating grease, 1st ed.", 5 February 2007, JAPANESE SOCIETY OF TRIBOLOGISTS , JP , ISBN: 978-4-8425-0415-5, article JAPAN TRIBOLOGY SOCIETY GREASE STUDY GROUP ED.: "Passage; Basics and applications of lubricating grease, 1st ed.", pages: 140 - 142, XP009534265 *

Also Published As

Publication number Publication date
CN115867631A (zh) 2023-03-28
JP2023100728A (ja) 2023-07-19
JP2022039847A (ja) 2022-03-10

Similar Documents

Publication Publication Date Title
KR101265168B1 (ko) 그리스 조성물 및 베어링
JP2005008744A (ja) グリース組成物
JP5729590B2 (ja) グリース組成物、グリース封入軸受、自在継手および直動装置
JP2009298890A (ja) 潤滑剤組成物
JP6401063B2 (ja) モータ用グリース封入軸受
WO2022045234A1 (ja) 転がり軸受
JP6534816B2 (ja) 転がり軸受
WO2022045233A1 (ja) グリース組成物および転がり軸受
JP2021063166A (ja) 潤滑剤組成物および転がり軸受
JP2008255272A (ja) 潤滑油組成物
JP2003327990A (ja) グリース組成物、転がり軸受及びスピンドルモータ
JP7511351B2 (ja) グリース組成物およびグリース封入軸受
EP4053252B1 (en) Low-dust grease composition for high-speed rotation, and bearing enclosing same
JP2007211874A (ja) 電動式リニアアクチュエータ
JP2008045100A (ja) グリース組成物及び転動装置
JP2014228059A (ja) 転がり軸受
JP5685141B2 (ja) グリース組成物、グリース封入軸受、自在継手および直動装置
JP2009185111A (ja) グリース組成物及び転がり軸受
WO2024048384A1 (ja) グリース組成物および転がり軸受
JP5267074B2 (ja) 正逆回転モータ用転がり軸受ユニット
JP2015021566A (ja) 転がり軸受
JP5887747B2 (ja) 工作機械主軸駆動スピンドルモータ用転がり軸受
WO2024058106A1 (ja) グリース組成物、転がり軸受および潤滑方法
JP2017025189A (ja) グリース組成物、グリース封入軸受、自在継手および直動装置
JP6461520B2 (ja) 工作機械用転がり軸受

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21861655

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21861655

Country of ref document: EP

Kind code of ref document: A1