WO2007063723A1 - 潤滑剤組成物とそれを用いた減速機ならびにそれを用いた電動パワーステアリング装置 - Google Patents

潤滑剤組成物とそれを用いた減速機ならびにそれを用いた電動パワーステアリング装置 Download PDF

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Publication number
WO2007063723A1
WO2007063723A1 PCT/JP2006/322968 JP2006322968W WO2007063723A1 WO 2007063723 A1 WO2007063723 A1 WO 2007063723A1 JP 2006322968 W JP2006322968 W JP 2006322968W WO 2007063723 A1 WO2007063723 A1 WO 2007063723A1
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WO
WIPO (PCT)
Prior art keywords
polyol
lubricant composition
polyurethane resin
electric power
power steering
Prior art date
Legal status (The legal status 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 status listed.)
Ceased
Application number
PCT/JP2006/322968
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English (en)
French (fr)
Japanese (ja)
Inventor
Kouji Kitahata
Naoki Uchida
Mitsuo Yoneda
Hiroaki Oka
Tomotaka Nakagawa
Masahiro Hayashi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Polyurethane Industry Co Ltd
JTEKT Corp
Original Assignee
Nippon Polyurethane Industry Co Ltd
JTEKT Corp
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 Nippon Polyurethane Industry Co Ltd, JTEKT Corp filed Critical Nippon Polyurethane Industry Co Ltd
Priority to EP06832847A priority Critical patent/EP1959004A4/en
Priority to US12/095,736 priority patent/US20100236859A1/en
Publication of WO2007063723A1 publication Critical patent/WO2007063723A1/ja
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B62LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62DMOTOR VEHICLES; TRAILERS
    • B62D5/00Power-assisted or power-driven steering
    • B62D5/04Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear
    • B62D5/0409Electric motor acting on the steering column
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10MLUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M149/00Lubricating compositions characterised by the additive being a macromolecular compound containing nitrogen
    • C10M149/12Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
    • C10M149/14Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds a condensation reaction being involved
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10MLUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M149/00Lubricating compositions characterised by the additive being a macromolecular compound containing nitrogen
    • C10M149/12Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
    • C10M149/14Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds a condensation reaction being involved
    • C10M149/20Polyureas
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10MLUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M169/00Lubricating 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
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16HGEARING
    • F16H57/00General details of gearing
    • F16H57/04Features relating to lubrication or cooling or heating
    • F16H57/041Coatings or solid lubricants, e.g. anti-seize layers or pastes
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16HGEARING
    • F16H57/00General details of gearing
    • F16H57/04Features relating to lubrication or cooling or heating
    • F16H57/0463Grease lubrication; Drop-feed lubrication
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10MLUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2205/00Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions
    • C10M2205/02Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers
    • C10M2205/028Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers containing aliphatic monomers having more than four carbon atoms
    • C10M2205/0285Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers containing aliphatic monomers having more than four carbon atoms used as base material
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10MLUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2207/00Organic non-macromolecular hydrocarbon compounds containing hydrogen, carbon and oxygen as ingredients in lubricant compositions
    • C10M2207/10Carboxylix acids; Neutral salts thereof
    • C10M2207/12Carboxylix acids; Neutral salts thereof having carboxyl groups bound to acyclic or cycloaliphatic carbon atoms
    • C10M2207/125Carboxylix acids; Neutral salts thereof having carboxyl groups bound to acyclic or cycloaliphatic carbon atoms having hydrocarbon chains of eight up to twenty-nine carbon atoms, i.e. fatty acids
    • C10M2207/1256Carboxylix acids; Neutral salts thereof having carboxyl groups bound to acyclic or cycloaliphatic carbon atoms having hydrocarbon chains of eight up to twenty-nine carbon atoms, i.e. fatty acids used as thickening agent
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10MLUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2217/00Organic macromolecular compounds containing nitrogen as ingredients in lubricant compositions
    • C10M2217/04Macromolecular compounds from nitrogen-containing monomers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
    • C10M2217/045Polyureas; Polyurethanes
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10NINDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2030/00Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
    • C10N2030/08Resistance to extreme temperature
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10NINDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2030/00Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
    • C10N2030/26Waterproofing or water resistance
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10NINDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2030/00Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
    • C10N2030/76Reduction of noise, shudder, or vibrations
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T74/00Machine element or mechanism
    • Y10T74/19Gearing
    • Y10T74/19991Lubrication

Definitions

  • the present invention relates to a lubricant composition, a speed reducer filled with the lubricant composition, and an electric power steering device including the speed reducer.
  • a reduction gear is used for an electric power steering device for an automobile.
  • the rotation of the electric motor is transmitted from the small gear such as the worm to the large gear such as the worm wheel in the speed reducer, so that the rotational speed is reduced and the output is amplified and then applied to the steering shaft. And torque assist the steering operation.
  • Appropriate backlash is required for the meshing between the small gear and the large gear.
  • the knocklash is too large, for example, when the rotation of both gears is reversed, or when the reaction force of the tire force is input by driving on a bad road such as a stone fold, etc. As a result, rattling noise may occur, and if it is transmitted as noise in the passenger compartment, it will cause driver discomfort.
  • Patent Document 1 the worm shaft is arranged so as to be deflectable toward the worm wheel, and the worm shaft is made elastic by using a spring or the like.
  • a reduction gear of an electric power steering device was proposed in which the knocklash between the two was substantially eliminated by biasing toward the worm wheel.
  • the above-described configuration has a problem that the structure of the speed reducer becomes complicated and the manufacturing cost increases. Therefore, in Patent Documents 2 and 3, a lubricant composition containing buffer material particles such as rubber and soft resin is filled in a region including at least a small gear and a large gear meshing portion of the reduction gear. Proposed to do. When the lubricant composition is used, the cushioning material particles are interposed between the tooth surfaces of both gears to buffer the collision between the tooth surfaces. Can be reduced.
  • the cushioning resin particles made of polyurethane resin can adjust the elasticity and hardness within an arbitrary range by selecting the types and ratios of the components that are the basis of polyurethane resin. can do. Therefore, the lubricant composition containing the polyurethane particles made of polyurethane resin, which is adjusted to have appropriate elasticity and hardness, is filled in a region including the squeezed joint portion of the small gear and the large gear. This reduces the rattling noise more effectively without increasing the steering torque of the electric power steering system or generating a sliding noise, which increases the noise in the passenger compartment. It becomes possible.
  • Patent Document 1 Japanese Unexamined Patent Publication No. 2000-43739 (Columns 0007 to 0009, FIG. 1)
  • Patent Document 2 Japanese Patent Laid-Open No. 2003-214529 (Claim 1, Columns 0005 to 0006)
  • Patent Document 3 Japanese Patent Laid-Open No. 2004-162018 (Claim 1, Column 0009)
  • Patent Document 4 Japanese Unexamined Patent Publication No. 2005-263989 (Claim 1, Item 0010)
  • an aromatic polyester polyol obtained by reacting an aromatic carboxylic acid and a low molecular weight polyol, which is used in the examples of Patent Document 4, and an aliphatic carboxylic acid and a low Aliphatic polyester polios reacted with molecular weight polyols
  • Polyurethane resin particles made of polyurethane resin synthesized in combination with a long-chain polyol as a long-chain polyol are used for a long period of time for a lubricant composition containing the above-mentioned buffer particles having low heat resistance and moisture resistance.
  • the polyurethane resin when used in a high temperature environment of approximately 120 ° C or higher, or when used for a long period of time in a high humidity environment, the polyurethane resin is hydrolyzed to lower the molecular weight.
  • the elastic modulus of the buffer particles decreases, or the adhesiveness increases with the low molecular weight, and the lubricant composition tends to aggregate in a lump. It became clear that there was a risk that it could not be obtained sufficiently.
  • An object of the present invention is to reduce the rattling noise without excessively increasing the steering torque of the electric power steering device or generating the sliding noise due to the buffer material particles.
  • the buffer particles are also excellent in heat resistance and moisture resistance, so even if they are used for a long period of time in a high temperature or high humidity environment.
  • An object of the present invention is to provide a lubricant composition capable of maintaining the above-mentioned effects satisfactorily.
  • the object of the present invention is to use the lubricant composition of the present invention, so that noise can be generated even if it is continuously used in a high temperature environment or a high humidity environment for a long period of time. It is an object of the present invention to provide a reduction gear and an electric power steering device using the reduction gear without fear of increasing the steering torque of the electric power steering device.
  • the present invention provides:
  • a lubricant composition comprising buffer particles made of polyurethane resin synthesized by reacting with a lubricant, and a lubricant.
  • the buffer particles composed of polyurethane resin synthesized using at least polycarbonate polyol as the polyol are aromatic polyester polyols used in the examples of Patent Document 4 above.
  • it has moderate elasticity and hardness equivalent to the buffer material particles made of polyurethane resin synthesized in combination with the aliphatic polyester polyol, and has higher heat resistance than the conventional buffer material particles.
  • Appetizing It has excellent wettability, especially if it is used for a long period of time in a high-temperature environment of approximately 120 ° C or higher, or even if it is used for a long period of time in a high-humidity environment.
  • the elastic modulus of the particles does not decrease or aggregate in a lump.
  • the lubricant composition of the present invention produces a rattling sound without excessively increasing the steering torque of the electric power steering device or generating a sliding noise due to the buffer material particles.
  • the cushioning material particles are also excellent in heat resistance and moisture resistance. Even if it continues to be used below, the above-mentioned effects can be maintained satisfactorily.
  • a polycarbonate polyol can be used as a polyol that is a raw material of polyurethane resin forming the buffer particles (Columns 0017, 0021). Column).
  • polycarbonate polyol As a polyol that is a raw material of polyurethane resin, it has moderate elasticity and hardness equivalent to the buffer particles used in the examples of Patent Document 4 described above.
  • the buffer particles having excellent heat resistance and moisture resistance can be obtained, and by using the buffer particles, the buffer particles can be used in a high temperature environment or at a high temperature for a long period of time.
  • Patent Document 4 completely describes that a lubricant composition that is unlikely to reduce the effect of reducing the rattling noise, etc., as described above can be obtained even if it is continuously used in a wet environment. Not. Therefore, the description relating to the polycarbonate polyol in Patent Document 4 does not disclose or suggest the present invention.
  • a polycarbonate polyol and an aromatic polyester polyol are used in combination as a polyol which is a raw material of polyurethane resin forming the buffer particles.
  • the aromatic polyester polyol P is a polycarbonate polyol which is a raw material of polyurethane resin forming the buffer particles.
  • the steering torque of the electric power steering device may be excessively increased or sliding noise may be generated. Without this, the effect of reducing the rattling noise can be maintained even better.
  • the long-chain polyols having a polyol power average molecular weight of 500 or more which are raw materials for polyurethane resin, including polycarbonate polyol.
  • the crosslinking agent L which is a raw material of polyurethane resin
  • the polyurethane particles formed by reacting the buffer material particles with a polyol, a crosslinking agent, and a polyisocyanate dispersed in a non-aqueous dispersion medium are preferred.
  • the fluidity of the lubricant composition can be improved, and the increase of the steering torque of the electric power steering apparatus can be prevented more reliably.
  • the speed reducer of the present invention includes a small gear and a large gear, and the region including the meshing portion of the two gears is filled with the lubricant composition of the present invention. Even if it continues to be used in a high temperature environment over a period, it is preferable in that the noise is small and there is no possibility of increasing the steering torque of the electric power steering device. In addition, since the electric power steering device of the present invention transmits the output of the steering assist motor to the steering mechanism via the reduction gear, the noise in the passenger compartment can be reduced at low cost. Is preferable.
  • the steering torque of the electric power steering device by the buffer material particles is reduced. It is excellent in the effect of reducing rattling noise and reducing noise in the passenger compartment without excessively raising or generating sliding noise.
  • a lubricant composition that is excellent in moisture resistance and can maintain the above-mentioned effects well even if it is used in a high temperature environment or a high humidity environment for a long period of time. Can do.
  • the use of the lubricant composition of the present invention makes it possible to reduce noise even when used for a long period of time in a high temperature environment or a high humidity environment.
  • FIG. 1 is a schematic cross-sectional view of an electric power steering apparatus according to an embodiment of the present invention.
  • FIG. 2 is a sectional view taken along line II-II in FIG.
  • FIG. 3 is a cross-sectional view illustrating a method for measuring the elastic modulus of buffer material particles of Examples and Comparative Examples.
  • FIG. 4 is a graph showing the transition of the elastic modulus of the buffer particles measured by the method of FIG. 3 according to the measured temperature.
  • the lubricant composition of the present invention comprises
  • It contains buffer material particles made of polyurethane resin synthesized by reacting with a lubricant and a lubricant.
  • the buffer particles are at least a poly force as a polyol. -Because it is made of polyurethane resin synthesized using bonate polyol, the shock-absorbing particles can be used without excessively increasing the steering torque of the electric power steering device or generating sliding noise. In addition to being excellent in the effect of reducing noise and reducing noise in the passenger compartment, the buffer particles are excellent in heat resistance and moisture resistance. Even if it continues to be used in a humid environment, the above-mentioned effects can be maintained in good condition.
  • polycarbonate polyol is synthesized by dealcoholization reaction or dephenol reaction of low molecular weight polyol and ethylene carbonate, jetino carbonate, diphenol carbonate or the like. And those having an average of two or more active hydrogen groups in one molecule.
  • the polycarbonate polyol may be used alone, but it is preferable to use the polycarbonate polyol and the aromatic polyester polyol in combination.
  • the aromatic polyester polyol include those synthesized by a reaction between a low molecular weight polyol and an aromatic carboxylic acid, and having an average of one or more active hydrogen groups in one molecule.
  • the upper limit of the ratio is not particularly limited, and as the polyol, polycarbonate polyol may be used alone. However, in consideration of sufficiently exerting the above-mentioned effects by using an aromatic polyester polyol in combination, the combination system of both the above polyols The ratio of polycarbonate polyol P to aromatic polyester polyol P
  • the crystallinity of the polyurethane resin forming the buffer particles is prevented from becoming extremely high, and its glass transition temperature Tg is controlled to the lowest possible range,
  • the elastic modulus of the buffer particles is improved in a normal environment in a temperature range of 20 ° C or higher and lower than the thermal decomposition temperature, and in a low temperature environment lower than the temperature range. Can be suppressed. Therefore, in a wider temperature range, the cushioning material particles are given good elasticity and hardness, without increasing the steering torque of the electric power steering device or generating sliding noise. The effect of reducing the hitting sound can be further improved.
  • all the polyols which are raw materials for polyurethane resin, containing at least a polycarbonate polyol, are long-chain polyols having a number average molecular weight of 500 or more.
  • the upper limit of the number average molecular weight of the polyol is not particularly limited.
  • polyol, a crosslinking agent, and a polyisocyanate are dispersed in a non-aqueous dispersion medium.
  • the polyol When producing spherical buffer particles by the so-called dispersion polymerization method, the polyol has a number average molecular weight of 5000 or less in order to disperse the polyol in the dispersion medium in as clean a spherical shape as possible. I like it! /
  • Examples of the low molecular weight polyol that is the basis of the polyol include ethylene glycol, 1,2 propanediol, 1,3 propanediol, 1,2 butanediol, 1,3 butanediol, 1,4 Butanediol, 1,5-pentanediol, 1,6-hexanediol, 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,8 octanediol, 1,9-nonanediol, Decamethylene glycol, diethylene glycol, dipropylene glycol, 2, 2-jetyl-1,3 propanediol, 2-n-butyl-2-ethyl-1,3 propane Diol, 2, 2, 4 Trimethyl-1,3 Pentanediol, 2 Ethyl-1,3 Hexanediol, 2-n-hex
  • the low molecular weight polyols include -COOH group-containing low molecular weight polyols such as 2,2 dimethylolpropionic acid and 2,2 dimethylolbutanoic acid;-COOH group-containing low molecular weight polyols and ammonia, organic amines, Salts with alkali metals, alkaline earth metals, etc .; Low molecular weight polyols containing sulfonic acid groups such as 2-sulfo-1,3 propanediol, 2-sulfo-1,4 butanediol; Low molecular weight polyols containing sulfonic acid groups and ammonia And salts with organic amines, alkali metals, alkaline earth metals, and the like.
  • the above compounds may be used alone or in combination of two or more.
  • the aromatic carboxylic acid that forms the aromatic polyester polyol together with the low molecular weight polyol includes, for example, phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, trimellitic acid, pyromellitic acid, and the like.
  • Polycarboxylic acids having no cationic group in the molecule sulfonic acid group-containing polycarboxylic acids such as 5-sulfo-isophthalic acid; the sulfonic acid group-containing polycarboxylic acids, ammonia, organic amines, alkali metals, Salts with alkaline earth metals, etc .; one or more of acid anhydrides, acid halides, alkyl esters, etc. of the polycarboxylic acid and sulfonic acid group-containing polycarboxylic acids.
  • sulfonic acid group-containing polycarboxylic acids such as 5-sulfo-isophthalic acid
  • the sulfonic acid group-containing polycarboxylic acids ammonia, organic amines, alkali metals, Salts with alkaline earth metals, etc .
  • polystyrene resin As the polyol, other polyols can be covered as long as the effects described above are not impaired by using at least the polycarbonate polyol or by using the polycarbonate polyol and the aromatic polyester polyol in combination. You can also. Above Each of the other polyols has an average of 1 or more active hydrogen groups in each molecule.
  • Aliphatic polyester polyols Aliphatic polyester polyols, polyamide ester polyols, polyether polyols, polyether ester polyols, polyolefin polyols, animal and plant polyols, dimer acid polyols, hydrogenated dimer acid polyols, and the like.
  • the various polyols also preferably have a number average molecular weight of 500 or more for the reason described above.
  • the cross-linking agent of (2) that forms a polyurethane resin that becomes the basis of the buffer material particles together with the polyol introduces a three-dimensional network structure into the polyurethane resin, and has an appropriate elasticity to the buffer material particles.
  • the crosslinking agent include various compounds having 3 or more active hydrogen groups in one molecule and preferably having a number average molecular weight of less than 500. It is done.
  • the crosslinking agent include polyols such as glycerin, sorbitol, trimethylolpropane, trimethylolbutane, trimethylolethane, 1,2,6-hexanetriol, pentaerythritol, triethanolamine, and diethanolamine.
  • N, N, N ′, N ′ amino alcohols such as tetra (hydroxypropyl) diamine, and the like, and trimethylolpropane and trimethylolbutane in which all active hydrogen groups are primary hydroxyl groups are particularly preferable.
  • LZP 0.5Zl to 3Zl.
  • the amount of the crosslinking agent is less than the above range, the three-dimensional network structure introduced into the polyurethane resin becomes too coarse and the buffer particles become too soft, so that the effect of reducing the noise of the reduction gear is obtained. There is a risk of not being able to.
  • the ratio of the crosslinking agent exceeds the above range, the three-dimensional network structure introduced into the polyurethane resin becomes too dense and the buffer particles become too hard. As a result of resistance, the steering torque of the electric power steering device may increase excessively or a sliding noise may occur.
  • the polyurethane resin that forms the buffer particles is formed.
  • the polyisocyanate (3) various polyisocyanates having at least two isocyanate groups in one molecule are used. These compounds can be used. Examples of the polyisocyanate include tolylene diisocyanate, xylylene diisocyanate, 4,4′-diphenolate methacrylate.
  • Aromatic diisocyanates such as diisocyanates; aliphatic diisocyanates such as 1,6-hexamethylene diisocyanate and 1,12-dodecane diisocyanate; cyclohexane-1,4-diisocyanate And alicyclic diisocyanates such as isophorone diisocyanate.
  • polyisocyanate an isocyanate group-terminated compound obtained by reacting each of the above-mentioned polyisocyanates with an active hydrogen group-containing compound; a carposidimide reaction, an isocyanurate one-toy reaction, etc.
  • isocyanate-modified products obtained by phosphine; phosgenates of condensates of errin and formaldehyde.
  • methanol, n-butanol, benzyl alcohol, ⁇ -force prolatatam, methyl ethyl ketone oxime, phenol, talesol, etc. are suitable blocking agents having one active hydrogen per molecule. It is also possible to use polyisocyanates that are stabilized in part or in whole.
  • the blending ratio of the polyisocyanate may be set so that the total amount of the equivalent power of the isocyanate group and the equivalent of the active hydrogen group of the polyol and the equivalent of the active hydrogen group of the cross-linking agent is approximately equal. Specifically, the blending ratio of the polyisocyanate is set so that it is 0.9 times to 1.1 times the total amount of the equivalent power of the isocyanate group and the active hydrogen group of the crosslinking agent. Preferred.
  • Buffer material particles made of polyurethane resin synthesized by reacting the above components may contain various additives as necessary.
  • additives include antioxidants for preventing deterioration of the polyurethane resin, anti-aging agents, flame retardants, etc., magnetic powder for imparting magnetism to buffer particles, and coloring for coloring particles. Agents and the like.
  • the average particle diameter D of the volume fraction of the buffer material particles is preferably 50 m ⁇ D ⁇ 300 ⁇ m. If the average particle size of the volume fraction D force is 0 / ⁇ ⁇ or less, there is a limit to the effect of reducing the rattling noise by buffering the impact of the small gear and the large gear. There is a risk that it cannot be significantly reduced. Further, when the average particle size D force of the volume fraction exceeds 3 ⁇ 400 m, the steering torque of the electric power steering device may increase or a sliding noise may be generated. Note that the average particle size of the volume fraction of the buffer material particles is 100 / zm or more, even within the above range, in consideration of further improving the effect of reducing the rattling noise. Preferably above. In consideration of preventing the generation of sliding noise more reliably if the steering torque is increased, it is particularly preferably 200 m or less even within the above range.
  • Buffer material particles can be produced by various methods. According to a dispersion polymerization method in which a polyol, a crosslinking agent, and a polyisocyanate are reacted in a state of being dispersed in a non-aqueous dispersion medium, While maintaining the spherical shape dispersed therein, it is possible to efficiently produce buffer particles having a uniform particle size.
  • a dispersion medium any of various non-aqueous organic solvents that do not dissolve at least the polyol and the polyurethane resin produced by the reaction can be used.
  • the dispersion medium preferably has a boiling point of 60 ° C or higher. If necessary, polar solvents such as toluene, butyl acetate, and methyl ethyl ketone may be used in combination as the dispersion medium.
  • a catalyst for promoting urethane foam may be added to the reaction system.
  • the catalyst include di-n-butyl tin dilaurate, stannous thiotoate, tertiary amines (N-methylmorpholine, triethylamine, etc.), lead naphthenate, lead octoate and the like.
  • the addition amount of the catalyst is preferably about 0.01 to 1 part by weight with respect to 100 parts by weight of the total amount of polyol, crosslinking agent and polyisocyanate.
  • a dispersion stabilizer may be added to the reaction system in order to stably disperse components such as polyol in a non-aqueous dispersion medium.
  • Any of various dispersion stabilizers (surfactant) can be used as the dispersion stabilizer.
  • Preferred dispersion stabilizers include, for example, 100 parts by weight of a polyester polyol or polycarbonate polyol having an unsaturated bond in the molecule, and an ethylenically unsaturated monomer 20 having a side chain composed of a hydrocarbon group having 6 or more carbon atoms. Examples include compounds obtained by reacting with ⁇ 400 parts by weight.
  • the dispersion stabilizer is preferably about 1 to 30 parts by weight with respect to 100 parts by weight of the total amount of polyol, crosslinking agent and polyisocyanate.
  • each component can be selected as appropriate, but is preferably performed according to the following procedure. That is, a polyol and a dispersion medium are charged into a reaction vessel of an apparatus, After adding a dispersion stabilizer and stirring vigorously to disperse the polyol in a spherical shape in the dispersion medium, the catalyst and the polyisocyanate are sequentially added.
  • a crosslinking agent is added to crosslink the polyurethane resin. Buffer material particles are produced.
  • the chain length of the polyurethane resin can be determined by titrating the concentration of the terminal isocyanate group in the polyurethane resin sampled from the container.
  • the force stirring conditions (stirring speed, temperature, etc.) can be adjusted, or the dispersion stabilizer can be adjusted.
  • the type and amount may be selected, and the type and amount of the dispersion medium may be selected.
  • the additive should be mixed in the polyol used for polymerization.
  • the content of the buffer particles is preferably 5 to 50 mass% of the total amount of the lubricant composition. If the content is less than the above range, the shock absorber particles are interposed in the meshing portion between the small gear and the large gear to absorb the impact, thereby reducing the rattling noise, thereby reducing the noise in the passenger compartment. There is a possibility that the effect of reducing the noise is not sufficiently obtained. Further, if the content exceeds the above range, the steering torque of the electric power steering device may increase or a sliding noise may be generated, which may increase the noise in the passenger compartment. Note that the content of the buffer material particles is preferably 15% by mass or more, even within the above range, in consideration of further improving the effect of reducing the rattling noise.
  • a liquid lubricating oil or a semi-solid grease may be used as the lubricant for dispersing the buffer particles.
  • the lubricating oil is preferably a synthetic hydrocarbon oil (for example, poly ⁇ -olefin oil), but synthetic oils such as silicone oil, fluorine oil, ester oil, ether oil, and mineral oil can also be used. Lubricating oils can be used alone or in combination of two or more.
  • Lubricants include solid lubricants (disulfurized molybdenum, graphite, PTFE, etc.), phosphorus-based and sulfur-based extreme pressure additives, and antioxidants such as tributylphenol and methylphenol as necessary. Further, an antifungal agent, a metal deactivator, a viscosity index improver, an oily agent and the like may be added. [0045]
  • the grease is represented by No. 2 to No. 000, especially No. 2 to No. 00, represented by a consistency strength NLGI (National Lubricating Grease Institute) number as a lubricant composition to which buffer material particles are added. Is preferably used.
  • the grease is formed by adding a thickening agent to a lubricating base oil as in the prior art.
  • the lubricating base oil is preferably a synthetic hydrocarbon oil (for example, poly ⁇ -olefin oil), but synthetic oils such as silicone oil, fluorine oil, ester oil and ether oil, mineral oil, and the like can also be used.
  • the kinematic viscosity of the lubricating base oil is preferably 5 to 200 mm 2 Zs (40 ° C.), more preferably 20 to L00 mm 2 Zs (40 ° C.).
  • As the thickener various conventionally known thickeners (soap and non-soap) can be used.
  • the grease may include solid lubricants (disulfurized molybdenum, graphite, PTFE, etc.), extreme pressure additives such as phosphorus and sulfur, antioxidants such as tributylphenol and methylphenol.
  • solid lubricants disulfurized molybdenum, graphite, PTFE, etc.
  • extreme pressure additives such as phosphorus and sulfur
  • antioxidants such as tributylphenol and methylphenol.
  • An antifungal agent, a metal deactivator, a viscosity index improver, an oily agent and the like may be added.
  • FIG. 1 is a schematic sectional view of an electric power steering apparatus according to an embodiment of the present invention.
  • FIG. 2 is a sectional view taken along line II-II in FIG.
  • a first steering shaft 2 as an input shaft to which a steering wheel 1 is attached, and a steering mechanism (not shown) such as a rack and pinion mechanism
  • the second steering shaft 3 serving as the output shaft is connected coaxially via a torsion bar 4.
  • the housing 5 that supports the first and second steering shafts 2 and 3 is made of, for example, an aluminum alloy and is attached to a vehicle body (not shown).
  • the housing 5 includes a sensor housing 6 and a gear housing 7 that are fitted together.
  • the gear housing 7 has a cylindrical shape, and the annular edge portion 7 a at the upper end thereof is fitted into the annular step portion 6 a at the outer periphery of the lower end of the sensor housing 6.
  • the gear housing 7 houses a worm gear mechanism 8 as a speed reduction mechanism, and the sensor housing 6 houses a torque sensor 9, a control board 10, and the like. By accommodating the worm gear mechanism 8 in the gear housing 7, the speed reducer 50 is configured.
  • the worm gear mechanism 8 includes a worm wheel 12 that can rotate integrally with an axially intermediate portion of the second steering shaft 3 and that is restricted from moving in the axial direction. And a worm shaft 11 (see FIG. 2) connected to the rotating shaft 32 of the electric motor M via a spline joint 33.
  • the worm wheel 12 is a synthetic resin having an annular cored bar 12a coupled to the second steering shaft 3 so as to be integrally rotatable, and teeth formed on the outer peripheral surface surrounding the cored bar 12a.
  • a member 12b for example, the core metal 12a is inserted into the mold at the time of resin molding of the synthetic resin member 12b.
  • the core metal 12a and the synthetic resin member 12b are combined and integrated by the resin molding in the inserted state.
  • the second steering shaft 3 is rotatably supported by first and second rolling bearings 13 and 14 that are disposed with the worm wheel 12 sandwiched vertically between them.
  • the outer ring 15 of the first rolling bearing 13 is fitted and held in a bearing holding hole 16 provided in the cylindrical projection 6b at the lower end of the sensor housing 6. Further, the upper end surface of the outer ring 15 is brought into contact with the annular step portion 17, whereby movement in the axial direction relative to the sensor housing 6 is restricted.
  • the inner ring 18 of the first rolling bearing 13 is fitted to the second steering shaft 3 by an interference fit. The lower end surface of the inner ring 18 is in contact with the upper end surface of the core metal 12a of the worm wheel 12.
  • the outer ring 19 of the second rolling bearing 14 is fitted and held in the bearing holding hole 20 of the gear housing 7. Further, the lower end surface of the outer ring 19 is in contact with the annular step portion 21, so that the movement downward in the axial direction with respect to the gear housing 7 is restricted.
  • the inner ring 22 of the second rolling bearing 14 is attached to the second steering shaft 3 in a state where it can rotate integrally and the relative movement in the axial direction is restricted. Further, the inner ring 22 is sandwiched between a step portion 23 of the second steering shaft 3 and a nut 24 that is tightened into a screw portion of the second steering shaft 3.
  • the torsion bar 4 passes through the first and second steering shafts 2 and 3.
  • the upper end 4a of the torsion bar 4 is connected to the first steering shaft 2 by a connecting pin 25 so as to be integrally rotatable, and the lower end 4b is connected to the second steering shaft 3 by a connecting pin 26 so as to be integrally rotatable.
  • the lower end of the second steering shaft 3 is connected to a steering mechanism such as a rack and pinion mechanism via an intermediate shaft (not shown).
  • the connecting pin 25 connects a third steering shaft 27 disposed coaxially with the first steering shaft 2 so as to be integrally rotatable with the first steering shaft 2. number 3
  • the steering shaft 27 passes through the tube 28 constituting the steering column.
  • the upper portion of the first steering shaft 2 is rotatably supported by the sensor housing 6 via a third rolling bearing 29 made of, for example, a needle roller bearing.
  • the reduced diameter portion 30 at the lower portion of the first steering shaft 2 and the hole 31 at the upper portion of the second steering shaft 3 regulate the relative rotation of the first and second steering shafts 2 and 3 within a predetermined range. In order to achieve this, a predetermined play is provided in the rotational direction, and they are fitted together.
  • worm shaft 11 is rotatably supported by fourth and fifth rolling bearings 34 and 35 held by gear housing 7.
  • the inner rings 36 and 37 of the fourth and fifth rolling bearings 34 and 35 are fitted into corresponding constricted portions of the worm shaft 11.
  • the outer rings 38 and 39 are held in the bearing holding holes 40 and 41 of the gear housing 7, respectively.
  • the gear housing 7 includes a portion 7 b that is opposed to a part of the peripheral surface of the worm shaft 11 in the radial direction.
  • the outer ring 38 of the fourth rolling bearing 34 that supports the one end portion 11 a of the worm shaft 11 is positioned in contact with the stepped portion 42 of the gear housing 7.
  • the inner ring 36 is restricted from moving toward the other end portion ib by contacting the positioning step 43 of the worm shaft 11.
  • the inner ring 37 of the fifth rolling bearing S 35 that supports the vicinity of the other end l ib (joint side end) of the worm shaft 11 is brought into contact with the positioning step 44 of the worm shaft 11. This restricts the movement toward the one end 11a.
  • the outer ring 39 is urged toward the fourth rolling bearing 34 by a preload adjusting screw member 45.
  • the screw member 45 is screwed into a screw hole 46 formed in the gear housing 7 to apply a preload to the pair of rolling bearings 34 and 35 and to position the worm shaft 11 in the axial direction.
  • 47 is a lock nut engaged with the screw member 45 in order to fix the screw member 45 after the preload adjustment.
  • the region including at least the meshing portion A of the worm shaft 11 and the worm wheel 12 is filled with the lubricant composition of the present invention described above. That is, the lubricant composition may be filled only in the mixed portion A, or may be filled in the entire periphery of the mixed portion V, the portion A and the worm shaft 11, and the entire gear housing 7. You may fill your body.
  • the present invention is not limited to the embodiment shown in FIGS. Example For example, the configuration of the speed reducer of the present invention can be applied to a speed reducer for devices other than the electric power steering device, and the like, within the scope of matters described in the claims of the present invention, Various modifications can be made.
  • a dispersion stabilizer N-5741 manufactured by Nippon Polyurethane Industry Co., Ltd.
  • reaction solution was sequentially analyzed, and when the concentration of the terminal isocyanate group reached 3.2%, 66 g of trimethylolpropane as a cross-linking agent (the number of moles of the trimethylolpropane was converted to polycarbonate.
  • the average particle size of the volume fraction of the buffer particles measured with a laser diffraction particle size distribution analyzer is 150 m, and the particle size distribution is 40 to 300. m.
  • the properties of a polyurethane resin sheet (thickness of about 2 mm) prepared with the same formulation excluding the dispersion stabilizer at a measurement temperature of 25 ° C are as follows: Shore A hardness H force 72, Japanese Industrial Standard J
  • the elongation at break EB was 300% and the strength at break TB was 30MPa, measured according to the measurement method described in 1995 "Physical Test Method for Vulcanized Rubber".
  • the sheet was formed by pouring a mixed solution of each component excluding the dispersion medium and the dispersion stabilizer into an iron dish-like container, heating to 90 ° C. and curing, and then aging at the same temperature.
  • the glass transition temperature Tg was -28 ° C.
  • polycarbonate polyol the same one as used in Example 1 was used.
  • polyol 607 g of the polycarbonate polyol and 107 g of the aromatic polyester polyol are blended, and the blending amount of the dispersion stabilizer (N-5741 manufactured by Nippon Polyurethane Industry Co., Ltd.) is 24 g, as the polyisocyanate.
  • the average particle size of the volume fraction of the buffer material particles measured using a laser diffraction particle size distribution meter is 150 m, and the particle size distribution is 40 to 300. m.
  • the physical properties of a polyurethane resin sheet (thickness of about 2 mm) prepared in the same manner as described above, excluding the dispersion stabilizer, at a measurement temperature of 25 ° C are as follows: Shore A hardness H 1 ⁇ 1
  • Example 2 The same polycarbonate polyol and aromatic polyester polyol as those used in Example 2 were used.
  • the polyol 482 g of the above polycarbonate polyol and 207 g of the aromatic polyester polyol are blended, and the blending amount of the dispersion stabilizer (N-5741 manufactured by Nippon Polyurethane Industry Co., Ltd.) is 23 g as the polyisocyanate.
  • the dispersion stabilizer N-5741 manufactured by Nippon Polyurethane Industry Co., Ltd.
  • Trimethylolpropane as a cross-linking agent was added when the concentration of the terminal isocyanate group reached 3.9%.
  • the average particle size of the volume fraction of the buffer material particles measured using a laser diffraction particle size distribution analyzer is 150 m, and the particle size distribution is 40 to 300. m.
  • the physical properties of a polyurethane resin sheet (thickness of about 2 mm) prepared in the same manner as described above, excluding the dispersion stabilizer, at a measurement temperature of 25 ° C are as follows: Shore A hardness H 1 ⁇ 1
  • Elongation at break EB was 320%, and strength at break TB was 31 MPa.
  • the glass transition temperature Tg was 32 ° C.
  • the same polycarbonate polyol and aromatic polyester polyol as those used in Example 2 were used.
  • the polyol 329 g of the above polycarbonate polyol and 329 g of the aromatic polyester polyol are blended, and the blending amount of the dispersion stabilizer (N-5741 manufactured by Nippon Polyurethane Industry Co., Ltd.) is 22 g as the polyisocyanate.
  • the blending amount of hexamethylene diisocyanate is 249g
  • the blending amount of trimethylolpropane as a crosslinking agent is 88g.
  • buffer material particles lOOOOg made of polyurethane resin were produced in the same manner as in Example 1.
  • the ratio of polycarbonate polyol P and aromatic polyester polyol P is the weight ratio P / P
  • Trimethylolpropane as a cross-linking agent was added when the concentration of the terminal isocyanate group reached 4.3%.
  • the average particle size of the volume fraction of the buffer material particles measured using a laser diffraction particle size distribution analyzer is 150 m, and the particle size distribution is 40 to 300. m.
  • the physical properties of a polyurethane resin sheet (thickness: about 2 mm) prepared in the same manner as described above except for the dispersion stabilizer at a measurement temperature of 25 ° C. are as follows: Shore A hardness H strength 8. Elongation at break EB was 270%, and strength at break TB was 29MPa. The glass transition temperature Tg was 25 ° C.
  • the same polycarbonate polyol and aromatic polyester polyol as those used in Example 2 were used.
  • As the polyol 257 g of the polycarbonate polyol and 386 g of the aromatic polyester polyol are blended, and the blending amount of the dispersion stabilizer (N-5741 manufactured by Nippon Polyurethane Industry Co., Ltd.) is 21 g, as the polyisocyanate.
  • the compounding amount of hexamethylene diisocyanate is 260 g
  • the compounding amount of trimethylolpropane as a crosslinking agent is 92 g
  • Molar ratio L of the above-mentioned number of moles of trimethylolpropane to the total number of moles of two polyols P LZP Except that it was set to 2Zl)
  • buffer material particles lOOOOg made of polyurethane resin were produced in the same manner as in Example 1.
  • the ratio of polycarbonate polyol P and aromatic polyester polyol P is the weight ratio P / P
  • Trimethylolpropane as a cross-linking agent was added when the concentration of the terminal isocyanate group reached 4.5%.
  • the average particle size of the volume fraction of the buffer material particles measured using a laser diffraction particle size distribution meter is 150 m, and the particle size distribution is 40 to 300. m.
  • the physical properties of a polyurethane resin sheet (thickness: about 2 mm) prepared in the same manner as described above except for the dispersion stabilizer at a measurement temperature of 25 ° C. are as follows: Shore A hardness H strength
  • Elongation at break EB was 290%, and strength at break TB was 28MPa.
  • the glass transition temperature Tg was 22 ° C.
  • the same polycarbonate polyol and aromatic polyester polyol as those used in Example 2 were used.
  • As the polyol 189 g of the polycarbonate polyol and 441 g of the aromatic polyester polyol are blended, and the blending amount of the dispersion stabilizer (N-5741 manufactured by Nippon Polyurethane Industry Co., Ltd.) is 21 g as the polyisocyanate.
  • buffer material particles lOOOOg made of polyurethane resin were prepared.
  • the ratio of polycarbonate polyol P and aromatic polyester polyol P is the weight ratio P / P
  • Trimethylolpropane as a cross-linking agent was added when the concentration of the terminal isocyanate group reached 4.7%.
  • the average particle size of the volume fraction of the buffer material particles measured using a laser diffraction particle size distribution analyzer is 150 m, and the particle size distribution is 40 to 300. m.
  • the physical properties of a polyurethane resin sheet (thickness: about 2 mm) prepared in the same manner as described above except for the dispersion stabilizer at a measurement temperature of 25 ° C. are as follows: Shore A hardness H strength
  • Elongation at break EB was 280% and strength at break TB was 27MPa.
  • the glass transition temperature Tg was 18 ° C.
  • the same aromatic polyester polyol as used in Example 2 was used.
  • the polyol 269 g of the aromatic polyester polyol and 404 g of the aliphatic polyester polyol are blended, and the blending amount of the dispersion stabilizer (N-5741 manufactured by Nippon Polyurethane Industry Co., Ltd.) is 22 g, polyisocyanate.
  • the average particle size of the volume fraction of the buffer material particles measured using a laser diffraction particle size distribution analyzer is 150 m, and the particle size distribution is 40 to 300. m.
  • the physical properties of a polyurethane resin sheet (thickness: about 2 mm) prepared in the same manner as described above except for the dispersion stabilizer at a measurement temperature of 25 ° C. are as follows: Shore A hardness H strength
  • Elongation at break EB was 320% and strength at break TB was 28MPa.
  • Glass transition temperature T g was 42 ° C.
  • the same aromatic polyester polyol and aliphatic polyester polyol as those used in Comparative Example 1 were used.
  • the polyol 107 g of the aromatic polyester polyol and 607 g of the aliphatic polyester polyol are blended, and the blending amount of the dispersion stabilizer (N-5741 manufactured by Nippon Polyurethane Industry Co., Ltd.) is 24 g as the polyisocyanate.
  • buffer material particles lOOOg made of polyurethane resin were produced in the same manner as in Example 1.
  • the ratio of aromatic polyester polyol p to aliphatic polyester polyol P is
  • the average particle size of the volume fraction of the buffer material particles measured using a laser diffraction particle size distribution analyzer was 150 m, and the particle size distribution was 40 to 300. m.
  • the physical properties of a polyurethane resin sheet (thickness: about 2 mm) prepared in the same manner as described above except for the dispersion stabilizer at a measurement temperature of 25 ° C. are as follows: Shore A hardness H strength
  • Elongation at break EB was 300% and strength at break TB was 25MPa.
  • the glass transition temperature Tg was 47 ° C.
  • the lubricant particles prepared in Examples 1 to 6 and Comparative Examples 1 and 2 were blended with grease obtained by adding a soap-type thickener to poly olefin oil to produce a grease as a lubricant composition. .
  • the content of the buffer particles was 5% by mass of the total amount of the lubricant composition.
  • the dally was filled in the speed reducer 50 of the electric power steering apparatus shown in FIGS.
  • As the worm gear mechanism 8 of the reduction gear 50 a combination of an iron metal worm shaft 11 and a worm wheel 12 in which a synthetic resin member 12b is formed of a polyamide resin is used.
  • the backlash was ⁇ .
  • the electric power steering In addition to measuring the strength of abnormal noise (db (A)) generated when the steering wheel 1 connected to the steering device was rotated, the steering torque (N'm) at that time was also measured. Measurements were made when grease immediately after production was filled into the reducer 50 (initial state) and when the grease was left in a 120 ° C oven for 1000 hours and then filled into the reducer 50 (thermal After the history), the heat resistance of the buffer material particles was evaluated by calculating the abnormal noise and the rate of change of the steering torque after the initial state and the thermal history.
  • Example 1 to 6 and Comparative Examples 1 and 2 the polyurethane resin sheet (thickness: about 2 mm) prepared for measuring physical properties was immersed in 80 ° C hot water for 250 hours and 1000 hours. Later, the strength at break TB was measured. Then, the retention strength after the immersion (%) for 250 hours and the retention rate (%) after immersion for 1000 hours with respect to the initial value before the immersion in warm water of the strength TB at break is obtained, and the buffer material is obtained. The moisture resistance of the particles was evaluated. The results are shown in Table 1.
  • the buffer particles of Comparative Examples 1 and 2 consisting of polyurethane resin synthesized by using an aromatic polyester polyol and an aliphatic polyester polyol in combination as the polyol are both insufficient in heat resistance and moisture resistance. It turned out that.
  • the buffer particles of Example 1 consisting of polyurethane resin synthesized using polycarbonate polyol as the polyol, and the polyurethane resin synthesized using polycarbonate polyol and aromatic polyester polyol as the polyol as polyol. It was found that all of the buffer particles of Examples 2 to 6 made of fat were excellent in heat resistance and moisture resistance. Also, each implementation Comparing the examples, the aromatic polyester polyol P of the polycarbonate polyol P
  • the ratio of the weight ratio P / P 40Z60 or more force of the heat resistance and moisture resistance
  • the buffer material particles 101 produced in Examples 2 and 4 and Comparative Example 2 were placed on a flat quartz base 102, and the tip surface was planar from above.
  • the buffer material particles 101 are captured by the detection rod 103 with a certain load F,
  • the distance G between the surface of the base 102 and the tip surface of the detection rod 103 when compressed in the direction of the base 102 is measured, and from the measurement result, the equation (1):
  • R is the radius before compression of the buffer material particles 101
  • S is the radius R of the buffer material particles 101 and the interval G
  • formula (2) is the formula (2):
  • the elastic modulus E of the buffer material particle 101 is calculated based on the measurement temperature in the temperature range from 40 ° C to + 100 ° C at every 5 ° C while changing the measurement temperature. The change in the elastic modulus E of the buffer material particles 101 according to the measurement temperature was determined. The results are shown in FIG.
  • Example 7 The same polycarbonate polyol and aromatic polyester polyol as those used in Example 2 were used. As the polyol, 741 g of the polycarbonate polyol and 13 lg of the aromatic polyester polyol are blended, and the blending amount of the dispersion stabilizer (N-5741 manufactured by Nippon Polyurethane Industry Co., Ltd.) is 29 g as the polyisocyanate.
  • the dispersion stabilizer N-5741 manufactured by Nippon Polyurethane Industry Co., Ltd.
  • Trimethylolpropane as a cross-linking agent was added when the concentration of the terminal isocyanate group reached 0.6%.
  • the average particle size of the volume fraction of the buffer material particles measured using a laser diffraction particle size distribution analyzer is 150 m, and the particle size distribution is 40 to 300. m.
  • the physical properties of a polyurethane resin sheet (thickness: about 2 mm) prepared in the same manner as described above except for the dispersion stabilizer at a measurement temperature of 25 ° C. are as follows: Shore A hardness H strength
  • Elongation at break EB was 450% and strength at break TB was 30 MPa.
  • the glass transition temperature Tg was 32 ° C.
  • the same polycarbonate polyol and aromatic polyester polyol as those used in Example 2 were used.
  • As the polyol 722 g of the above polycarbonate polyol and 127 g of the aromatic polyester polyol are blended, and the blending amount of the dispersion stabilizer (N-5741 manufactured by Nippon Polyurethane Industry Co., Ltd.) is 28 g as the polyisocyanate.
  • the compounding amount of hexamethylene diisocyanate is 123g
  • the compounding amount of trimethylolpropane as a cross-linking agent is 22g
  • Buffer material particles lOOOg made of polyurethane resin were prepared in the same manner as in Example 1 except that it was equivalent to 0.5Z1).
  • the ratio of polycarbonate polyol P and aromatic polyester polyol P is the weight ratio P / P
  • Trimethylolpropane as a crosslinker has a terminal isocyanate group. Was added when the concentration reached 1.0%.
  • the average particle size of the volume fraction of the buffer material particles measured using a laser diffraction particle size distribution meter is 150 m, and the particle size distribution is 40 to 300. m.
  • the physical properties of a polyurethane resin sheet (thickness: about 2 mm) prepared in the same manner as described above except for the dispersion stabilizer at a measurement temperature of 25 ° C. are as follows: Shore A hardness H strength
  • Elongation at break EB was 420% and strength at break TB was 33 MPa.
  • the glass transition temperature Tg was 33 ° C.
  • Example 2 The same polycarbonate polyol and aromatic polyester polyol as those used in Example 2 were used.
  • the polyol 679 g of the polycarbonate polyol and 120 g of the aromatic polyester polyol are blended, and the blending amount of the dispersion stabilizer (N-5741 manufactured by Nippon Polyurethane Industry Co., Ltd.) is 27 g as the polyisocyanate.
  • the dispersion stabilizer N-5741 manufactured by Nippon Polyurethane Industry Co., Ltd.
  • the ratio of polycarbonate polyol P and aromatic polyester polyol P is the weight ratio P / P
  • Trimethylolpropane as a cross-linking agent was added when the concentration of the terminal isocyanate group reached 2.0%.
  • the average particle size of the volume fraction of the buffer material particles measured using a laser diffraction particle size distribution meter is 150 m, and the particle size distribution is 40 to 300. m.
  • the physical properties of a polyurethane resin sheet (thickness: about 2 mm) prepared in the same manner as described above except for the dispersion stabilizer at a measurement temperature of 25 ° C. are as follows: Shore A hardness H strength
  • Elongation at break EB was 380% and strength at break TB was 29 MPa.
  • the glass transition temperature Tg was 34 ° C.
  • Example 2 The same polycarbonate polyol and aromatic polyester polyol as those used in Example 2 were used. And as the polyol, the polycarbonate 549 g of polyol and 97 g of aromatic polyester polyol, 22 g of dispersion stabilizer (N-5741 made by Nippon Polyurethane Industry Co., Ltd.), hexamethylene diiso- sane as polyisocyanate.
  • dispersion stabilizer N-5741 made by Nippon Polyurethane Industry Co., Ltd.
  • hexamethylene diiso- sane as polyisocyanate.
  • the ratio of polycarbonate polyol P and aromatic polyester polyol P is the weight ratio P / P
  • Trimethylolpropane as a crosslinking agent was added when the concentration of the terminal isocyanate group reached 4.9%.
  • the average particle size of the volume fraction of the buffer material particles measured using a laser diffraction particle size distribution analyzer is 150 m, and the particle size distribution is 40 to 300. m.
  • the physical properties of a polyurethane resin sheet (thickness of about 2 mm) prepared in the same manner as described above, excluding the dispersion stabilizer, at a measurement temperature of 25 ° C are as follows: Shore A hardness H 1 ⁇ 1
  • Elongation at break EB was 180%, strength at break TB force 3MPa.
  • the glass transition temperature Tg was 34 ° C.
  • Example 2 The same polycarbonate polyol and aromatic polyester polyol as those used in Example 2 were used.
  • the polyol 533 g of the above-mentioned polycarbonate polyol and 94 g of the aromatic polyester polyol are blended, and the blending amount of the dispersion stabilizer (N-5741 manufactured by Nippon Polyurethane Industry Co., Ltd.) is 21 g, polyisocyanate.
  • Trimethylolpropane as a crosslinking agent was added when the terminal isocyanate group concentration reached 5.3%.
  • Measurement was performed using a laser diffraction particle size distribution analyzer (registered trademark Microtrac manufactured by Nikkiso Co., Ltd.).
  • the determined buffer particles had an average volume fraction particle size of 150 m and a particle size distribution of 40 to 300 m.
  • the physical properties of a polyurethane resin sheet (thickness of about 2 mm) prepared in the same manner as described above, excluding the dispersion stabilizer, at a measurement temperature of 25 ° C are as follows: Shore A hardness H 1 ⁇ 1
  • Example 7 ⁇ The buffer particles produced in L1 were subjected to the above heat resistance test and moisture resistance test, and their characteristics were evaluated. The results are shown in Table 2 together with the results of Example 2.
  • the buffer particles in Examples 2 and 7 to 11 made of polyurethane resin synthesized by using a polycarbonate polyol and an aromatic polyester polyol in combination as the polyol are both resistant to heat and moisture. It turned out to be excellent.

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PCT/JP2006/322968 2005-12-02 2006-11-17 潤滑剤組成物とそれを用いた減速機ならびにそれを用いた電動パワーステアリング装置 Ceased WO2007063723A1 (ja)

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EP06832847A EP1959004A4 (en) 2005-12-02 2006-11-17 LUBRICANT COMPOSITION, LOWERING GEAR, USED THEREOF AND ELECTRIC POWER STEERING DEVICE USING THEREOF
US12/095,736 US20100236859A1 (en) 2005-12-02 2006-11-17 Lubricant composition, speed reduction gear employing the composition and electric power steering apparatus employing the speed reduction gear

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JP2005349523A JP5127135B2 (ja) 2005-12-02 2005-12-02 潤滑剤組成物とそれを用いた減速機ならびにそれを用いた電動パワーステアリング装置
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US7728071B2 (en) 2006-05-12 2010-06-01 E. I. Du Pont De Nemours And Company Gear for electric power steering device
JP2009114259A (ja) * 2007-11-02 2009-05-28 Jtekt Corp 潤滑剤組成物とそれを用いた減速機および電動パワーステアリング装置
WO2011065491A1 (ja) * 2009-11-27 2011-06-03 日本精工株式会社 電動式パワーステアリング装置
US8919489B2 (en) * 2010-12-07 2014-12-30 Nsk Ltd. Electric power steering apparatus
JP6481261B2 (ja) * 2014-04-16 2019-03-13 株式会社ジェイテクト 車両用差動装置
US20180086364A1 (en) * 2016-09-23 2018-03-29 Mando Corporation Steering column for vehicle
CN120739841B (zh) * 2025-09-04 2025-11-28 泰州吉丰传动科技有限公司 一种海洋船舶用的电缆牵引减速传动装置

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11286601A (ja) * 1998-04-01 1999-10-19 Nippon Mektron Ltd 自己潤滑性ポリウレタンエラストマーの製造法
JP2000302835A (ja) * 1999-04-22 2000-10-31 Nippon Polyurethane Ind Co Ltd 熱可塑性ポリウレタン樹脂の製造方法
JP2001055437A (ja) * 1999-08-20 2001-02-27 Nippon Polyurethane Ind Co Ltd ポリカーボネートジオールの製造方法
WO2004029184A1 (ja) * 2002-09-25 2004-04-08 Koyo Seiko Co., Ltd. 潤滑剤組成物とそれを用いた減速機ならびにそれを用いた電動パワーステアリング装置
JP2005263989A (ja) * 2004-03-18 2005-09-29 Koyo Seiko Co Ltd 潤滑剤組成物とそれを用いた減速機ならびにそれを用いた電動パワーステアリング装置

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19513164A1 (de) * 1995-04-07 1996-10-10 Bayer Ag Polycarbonat-Diole, ihre Herstellung und Verwendung als Ausgangsprodukte für Polyurethan-Kunststoffe

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11286601A (ja) * 1998-04-01 1999-10-19 Nippon Mektron Ltd 自己潤滑性ポリウレタンエラストマーの製造法
JP2000302835A (ja) * 1999-04-22 2000-10-31 Nippon Polyurethane Ind Co Ltd 熱可塑性ポリウレタン樹脂の製造方法
JP2001055437A (ja) * 1999-08-20 2001-02-27 Nippon Polyurethane Ind Co Ltd ポリカーボネートジオールの製造方法
WO2004029184A1 (ja) * 2002-09-25 2004-04-08 Koyo Seiko Co., Ltd. 潤滑剤組成物とそれを用いた減速機ならびにそれを用いた電動パワーステアリング装置
JP2005263989A (ja) * 2004-03-18 2005-09-29 Koyo Seiko Co Ltd 潤滑剤組成物とそれを用いた減速機ならびにそれを用いた電動パワーステアリング装置

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP1959004A4 *

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