JP6583994B2 - Method for producing lubricant applied to at least one of raceway surface or rolling element of rolling bearing device, or method for producing lubricant applied to at least one sliding surface of bearing member or shaft member of sliding bearing device - Google Patents

Description

The present invention relates to a method for manufacturing a lubricant to be applied to at least one of a raceway surface or a rolling element of a rolling bearing device, or a method for manufacturing a lubricant to be applied to a sliding surface of a bearing member or a shaft member of a sliding bearing device .

Industrial equipment having a rotating part has a bearing device including a rotating shaft member and a bearing member that supports the rotation and load of the shaft member. In the bearing device, members that support the rotation and load of the shaft member are: 1. Excellent durability. 2. Do not cause seizure or adhesion; 3. Less frictional heat; It is required that the frictional sound is low.
The bearing device is divided into a rolling bearing device and a sliding bearing device. In the rolling bearing, a part called a rolling element supports the rotation and load of the shaft member. This rolling element is held by a cage and rolls on a raceway surface composed of an inner ring and an outer ring. There are various types of rolling bearings depending on the type of rolling element, and there are ball bearings by rolling of ball bearings and roller bearings by rolling of cylindrical rollers, conical rollers, needle rollers, and the like. On the other hand, the sliding bearing supports the rotation and load of the shaft member with an oil film of lubricating oil present on the sliding surface. Oil-impregnated bearings that omit the means for supplying lubricating oil to the sliding surface are smaller and less expensive than the hydrodynamic and hydrostatic bearings that supply lubricating oil to the sliding surface. Compared to pressure bearings, it is used in more industrial equipment.

Since the rolling bearing device has a cage for holding the rolling elements, the rolling bearing device becomes a large-sized bearing device as compared with the oil-impregnated bearing, and the quietness is inferior to the sliding bearing device due to the rolling of the rolling elements. On the other hand, when the shaft member rotates at a high speed, the inertial force of the rolling element increases and an excessive compressive stress is applied to the raceway surface. Further, a compressive stress is always applied to the raceway surface of the rolling element even under a static load. For this reason, a scaly fatigue peeling phenomenon caused by a compressive load called flaking occurs on the rolling elements or the raceway surface, and this flaking progresses at an accelerated rate to determine the life of the rolling bearing device.
On the other hand, the area where the rolling element contacts the raceway surface is smaller than the sliding surface where the shaft member in the sliding bearing device contacts. For this reason, the frictional force at the time of operation | movement is small compared with a slide bearing apparatus. Further, unlike the sliding bearing device, it is not affected by the operating temperature. Further, in the sliding bearing device, a bearing member corresponding to the magnitude of the load of the shaft member must be used. However, in the rolling bearing, there is no restriction on the load received by the rolling elements and the raceway surface. Therefore, if the load applied to the rolling elements and the raceway surface in the rolling bearing device can be reduced, and if the frictional force between the rolling elements and the raceway surface can be reduced, there will be no weak points related to durability and quietness, and a general-purpose bearing device will be realized. Become.

As means for solving the problems of rolling bearings, for example, in Patent Document 1, rings formed of solid lubricant on both sides of an array of rolling elements between inner and outer rings, and an elastic member that presses the lubricating rings against the rolling elements, There has been proposed a rolling bearing in which a solid lubricant is transferred from a lubrication ring to a rolling element to perform lubrication. However, since the solid lubricant is supplied to the rolling elements only from the axial direction, the solid lubricant is difficult to enter between the rolling elements and the rolling surfaces of the inner and outer rings, and sufficient lubrication is not performed. There is a risk of wearing. Further, when the solid lubricant is worn, seizure and adhesion occur, and the life of the solid lubricant becomes the life of the rolling bearing. Therefore, the technique proposed in this patent document cannot fundamentally solve the conventional problems.
Further, in Patent Document 2, even if a small amount of lubricating oil is supplied to the contact surface where rolling contact or sliding contact occurs, a uniform oil film is formed, and the rolling slide having a contact surface with a small and uniform friction coefficient. For the purpose of providing a moving member, there is a rolling bearing in which a large number of fine recesses are formed on the outer raceway surface, the inner raceway surface and the rolling surface, which are rolling contact surfaces, and an oil repellent is attached to the inner surface of the recesses. Proposed. However, the operating temperature is limited by the vapor pressure characteristics and viscosity of the oil repellent. Further, the bearing device is based on the premise that the oil repellent is supplied to the contact surface, and the life of the oil repellent is the life of the bearing device. Therefore, the technique proposed in this patent document cannot fundamentally solve the conventional problems.

On the other hand, the sliding bearing device receives the rotation and load of the shaft member with the lubricating oil film on the sliding surface of the bearing member, so when the lubricating oil film is depleted, seizure and adhesion occur on the sliding surface, and the sliding bearing device The lifetime of is determined. Since the lubricating oil has a vapor pressure corresponding to the temperature, the operating life is shorter as the operating temperature is higher. Further, since the viscosity of the lubricating oil increases at a low temperature, the low-temperature startability of the shaft member is deteriorated. In order to extend the operating life, the use of a lubrication device that supplies lubricating oil to a sliding surface or a hydrodynamic / hydrostatic bearing provided with a lubrication mechanism eliminates the advantages of a small and inexpensive sliding bearing device.
In oil-impregnated bearings, the porous body is vacuum impregnated with lubricating oil. The vacuum-impregnated lubricating oil expands in volume by frictional heat of the sliding surface and has a self-lubricating property that supplies the lubricating oil to the sliding surface. The lubricating oil that has oozed out on the sliding surface forms an oil film on the sliding surface. The presence of this oil film prevents seizure and adhesion between the porous body and the shaft member. However, the volume of internal pores provided in the porous body is limited to more than 30%, and the operating life is determined by the limited amount of impregnated oil. Further, since the porous body has a structure in which the lubricating oil can be vacuum-impregnated inside the porous body and a structure in which the lubricating oil can be supplied to the sliding surface, the pores have air permeability. This air permeability restricts the load that the oil-impregnated bearing can be used.
That is, the oil pressure of the sliding surface escapes due to the air-permeable pores existing on the sliding surface, and the bearing surface pressure to which the oil-impregnated bearing can be applied is up to 1 MPa. Furthermore, in high-speed rotation, the lubricating oil supplied to the sliding surface becomes too small due to air-permeable pores, and the sliding speed of the shaft member that can be applied with the oil-impregnated bearing is limited to 300 m / min.
Furthermore, there is a limit to the area where oil-impregnated bearings can be applied because of the friction coefficient of the lubricating oil on the sliding surface. That is, when the lubricating oil that has oozed out from the pores performs ideal fluid lubrication on the sliding surface, the friction coefficient μ is given by μ = η · N · d / P · C. Here, η is the viscosity of the lubricating oil at the operating temperature, N is the rotational speed of the shaft member, d is the shaft diameter of the shaft member, P is the bearing surface pressure, and C is the clearance of the sliding contact surface. On the other hand, in the oil-impregnated bearing, when the rotational speed N of the shaft member decreases and the bearing surface pressure P increases, the friction coefficient μ during operation increases away from the ideal friction coefficient μ. That is, when the bearing surface pressure P increases during low-speed rotation, the bearing surface pressure P easily leaks due to the air permeability of the pores, and no oil film exists on the sliding surface, so that the shaft member and the bearing member are in direct contact with each other. The friction of the boundary lubrication becomes dominant, and seizure and adhesion on the sliding surface easily occur.

Various proposals have been made for various problems of such oil-impregnated bearings. For example, in order to expand the friction coefficient at which boundary lubrication occurs to a region with a smaller friction coefficient, that is, in order to expand the fluid lubrication region, there are cases in which molybdenum disulfide or graphite, which is a solid lubricant, is added to sintered metal. (For example, see Patent Documents 3 and 4). However, although there is an effect that the region of fluid lubrication is somewhat widened, there is a limit to the region where fluid lubrication is spread due to the air permeability of the pores of the sliding surface.
In addition, there is a case where a nonpolar lubricating oil having a high adsorption activity and a bearing material having a high adsorption activity are combined with the property that the lubricating oil is easily adsorbed on the sliding surface (see, for example, Non-Patent Documents 1 and 2). Even in this case, there is an effect that the region of fluid lubrication is somewhat widened, but there is a limit to the region where fluid lubrication is spread due to the air permeability of the pores of the sliding surface.

JP 2008-014411 A JP 2013-076469 A JP 2001-279349 A JP 2008-202123 A

Mori, Masayuki, Relationship between solid surface activity and adsorption and boundary lubrication, lubrication, Vol. 33, No8 (1988), 585-590 Mori, Masayuki, Chemical properties of frictional new surfaces, tribologists, Vol. 38, no. 10 (1993), 884-889

As described in the third paragraph, the problems in the rolling bearing device are summarized in that the load applied to the rolling element and the raceway surface is reduced, and the frictional force between the rolling element and the raceway surface is reduced. However, these problems occur based on the operating principle of the rolling bearing in which the rolling element supports the rotation and load of the rotating shaft member. On the other hand, if a means such as formation of a solid lubricating film or addition of an oil repellent agent is used on the rolling element or raceway surface as in the prior art described in the fourth paragraph, the life in high temperature operation which is a fundamental problem of the sliding bearing Shortening and deterioration of cold startability are brought about, and the bearing device is further increased in size, the disadvantages of the rolling bearing are increased, and a general-purpose rolling bearing device cannot be obtained.
On the other hand, the sliding bearing device is premised on that a lubricating oil film always exists on the sliding surface. Providing a device or mechanism for supplying lubricating oil to the sliding surface eliminates the advantages of a small and inexpensive sliding bearing. The problems of the oil-impregnated bearing are summarized in the following seven, but these problems are based on the principle of the oil-impregnated bearing and the nature of the lubricating oil to be impregnated, and the fundamental solution is difficult. First, when the bearing surface pressure increases due to an excessive axial load, the bearing surface pressure leaks from the pores of the sliding surface, leading to boundary lubrication. Second, when the shaft member rotates at a high speed, the force for drawing the lubricating oil to the sliding surface becomes strong, and the lubricating oil is easily depleted. Third, when the shaft member rotates at a low speed, the force for drawing the lubricating oil to the sliding surface becomes weak, and boundary lubrication occurs. Fourth, at extremely low temperatures, the viscosity of the lubricating oil increases, the friction coefficient increases, and the low-temperature startability deteriorates. Fifth, low temperature operation makes it difficult to supply lubricating oil to the sliding surface, leading to boundary lubrication. Sixth, in high-temperature operation, the lubricating oil supplied to the sliding surface becomes excessive, the evaporation of the lubricating oil increases, and the impregnated oil is easily depleted. Seventh, in high temperature operation, the thermal deterioration of the lubricating oil proceeds and the lubricating performance of the lubricating oil decreases.
Therefore, the means for fundamentally solving the problems of both the rolling bearing device and the sliding bearing device is, first of all, the function of self-lubricating to relieve the stress applied by sliding itself when stressed. It is to realize a lubricant having the same. In other words, if the lubricant film formed on the rolling elements and the raceway surface of the rolling bearing device is permanent, the load applied to the rolling elements and the raceway surface is permanently reduced, and the frictional force between the rolling elements and the raceway surface is reduced. Can be permanently reduced. Further, in the sliding bearing device, if the film made of the lubricant formed on the sliding surface is permanent, the stress applied to the sliding surface can be permanently relaxed. Secondly, if a film can be formed only by applying the above-described lubricant to at least one of the rolling elements and the raceway surface, the rolling bearing device will not be enlarged, and an inexpensive and general-purpose rolling bearing device will be obtained. Further, if a film can be formed only by applying the above-described lubricant to at least one of the sliding surfaces of the shaft member and the bearing member, an inexpensive and general-purpose sliding bearing device can be obtained. Third, the self-lubricating function is permanent regardless of the rotational speed and load of the shaft member and regardless of the operating temperature of the bearing device. As a result, durability and quietness in the rolling bearing device are maintained, and fluid lubrication on the sliding surface in the sliding bearing device is maintained. It is a problem to be solved by the present invention to realize a completely new lubricant having these three properties.

A method for producing a lubricant to be applied to at least one of a raceway surface or a rolling element of a rolling bearing device in which a rolling element according to the present invention and an inner ring and an outer ring are made of a soft magnetic body, or a sliding member in which a shaft member is a soft magnetic body. A method for producing a lubricant to be applied to at least one sliding surface of a bearing member or a shaft member of a bearing device is to produce an alcohol dispersion by dispersing ferrous naphthenate, which precipitates ferrous oxide by thermal decomposition, in alcohol. And a first property of the alcohol dispersion having a melting point lower than the pour point of a lubricating oil composed of a paraffinic base oil, and a boiling point higher than the temperature at which the ferrous oxide is oxidized to magnetite or maghemite. a second nature, a third nature incompatible with the lubricating oil, a fourth property of dissolving or mixing in the alcohol, the high viscosity than the alcohol Comprising a fifth property, esters of these five properties consisting unsaturated carboxylic acids having both a carboxylic acid, or esters of carboxylic acids comprising an aromatic carboxylic acid, or, of carboxylic acids consisting of a dicarboxylic acid A second step of preparing a mixed solution by mixing organic compounds belonging to any one of the esters of carboxylic acid , and heat-treating the mixed solution in an air atmosphere to heat the ferrous naphthenate It decomposes to produce granular fine particles of ferrous oxide, further raises the temperature, oxidizes the granular fine particles of ferrous oxide to granular fine particles of magnetite or maghemite, and any one of the magnetite or maghemite in the mixed solution or the other and a third step of Ru to precipitate a collection of granular particles made of a material, the mixture was heat-treated at the third step, paraffins Stirring a mixture of lubricating oil consisting of a system base oil, suspension consists of a fourth step of creating a lubricant consisting Nigoeki, these four steps to be performed continuously comprising the suspension lubricant Is a method for producing a lubricant.

That is, according to this production method, a lubricant having an epoch-making action and effect is produced when four simple steps are continuously performed. The first step is a treatment in which ferrous naphthenate, which is a general industrial chemical, is dispersed in alcohol. The second step is a carboxylic acid ester composed of unsaturated carboxylic acid, a carboxylic acid ester composed of aromatic carboxylic acid, or a carboxylic acid ester composed of dicarboxylic acid, which is a general industrial chemical. The organic compound belonging to any one kind of carboxylic acid ester is simply mixed with the alcohol dispersion. The third step is simply a heat treatment of the mixed solution in an air atmosphere. The fourth step is a process in which the lubricating oil is mixed with the heat-treated liquid mixture and stirred. Therefore, lubricant manufactured at low cost by using inexpensive raw materials.
By applying this lubricant to at least one of the raceway surface or rolling element of a rolling bearing, or to at least one sliding surface of a bearing member or shaft member of a sliding bearing, two kinds of liquids having self-lubricating properties can be obtained. A coating composed of a collection of three kinds of fine particles consisting of spherical fine particles and self-lubricating solid granular fine particles is formed on both the rolling element and the raceway surface, or on both the bearing member and the shaft member. Formed on the surface. As a result, in the rolling bearing, the durability of the rolling elements and the raceway is greatly increased, and the quietness is remarkably improved. In the sliding bearing, fluid lubrication is continued on the sliding surface, and silence is maintained. A bearing device having such breakthrough performance can be realized simply by applying a lubricant according to the present manufacturing method to the bearing device. As a result, an epoch-making bearing device based on a completely new mechanism can be realized at low cost using inexpensive raw materials .
That is, the lubricant that by the present production method, applied to at least one of the raceway surface or rolling element of a rolling bearing device, or, applied to at least one of the sliding surface of the bearing member or the shaft member of the sliding bearing device. Even if the particles of the organic compound and the lubricating oil in the suspension are not sufficiently finely divided, if the rolling element rolls on the raceway surface, or if the shaft member slides on the sliding surface of the bearing member, the organic compound And lubricating oil particles are crushed under shearing stress or compressive stress, and they are not compatible with each other, so they become finer particles. Since the stress applied to the particles is consumed when the particles are crushed, the particles do not attack the rolling elements and the raceway surface, or the sliding surface between the bearing member and the shaft member. In the micronization of particles, micron-sized liquid particles in the lubricant become submicron-sized spherical particles having the most stable shape, and the micronization is completed. Since the submicron spherical fine particles do not become smaller particles even when stressed, they exhibit self-lubricating properties that relieve stress by slipping themselves when stressed.
In addition, when creating a suspension with an ultrasonic homogenizer, the formation of fine particles of an organic compound and a lubricating oil proceeds in a short time. That is, when ultrasonic vibration is applied to the liquid, pressurization and decompression due to the longitudinal vibration of the ultrasonic waves are repeated with the liquid at an extremely short period according to the frequency of the ultrasonic wave, and a large pressure difference is generated in the liquid. Due to this pressure difference, minute bubbles (cavitation) are generated, and a large shock wave is generated at the moment when the bubble is subjected to longitudinal vibration in the liquid and bounces or collapses, and the particles are torn off and collide with each other, Particles are made fine in a short time. The fine particle formation proceeds to spherical fine particles that are not crushed by shock waves, and the spherical fine particles have self-lubricating properties that relieve stress by slipping themselves when subjected to stress.
On the other hand, solid metal oxide fine particles are hard granular fine particles having a size of several tens of nanometers. When the rolling element rolls on the raceway surface, or when the shaft member slides on the sliding surface of the bearing member, the particulate fine particles are also subjected to shear stress or compressive stress. At this time, since the particulate fine particles are not broken and have a granular shape, they exhibit self-lubricating properties that relieve stress by sliding themselves. In this way, a coating composed of a collection of three kinds of fine particles consisting of solid fine particles of metal oxide and spherical fine particles of a liquid organic compound and lubricating oil is formed on the rolling elements and the raceway surface, or the bearing member. It is formed on the sliding surface with the shaft member. Therefore, when the rolling element rolls on the raceway surface, or the shaft member slides on the sliding surface of the bearing member, shear stress or compressive stress is applied to the three kinds of fine particles, and the three kinds of fine particles slide to cause rolling. It does not attack the moving body and the raceway surface, or the sliding surface between the bearing member and the shaft member. On the other hand, the frictional force due to the contact between the solid granular fine particles and the liquid spherical fine particles is small because the liquid spherical fine particles slide preferentially. Further, the frictional force due to the contact between the liquid spherical fine particles is small because both slip. As a result, in the rolling bearing device, the durability between the rolling elements and the raceway surface is dramatically increased and the quietness is remarkably improved. On the other hand, in the sliding bearing device, fluid lubrication continues on the sliding surface, and quietness is maintained. A bearing device with such breakthrough performance, achieved by by that the lubricant in this manufacturing method.
In addition, since the metal oxide is a hard magnetic material having spontaneous magnetization, the rolling element of the rolling bearing device and the inner ring and the outer ring are soft magnetic materials, or the shaft member of the sliding bearing device is a soft magnetic material. The magnetic fine particles act on the metal oxide particulates between the rolling elements and the raceway surface, or between the shaft members, and the solid particulates and liquid spherical particulates having almost no mass. Does not fall off by the magnetic attractive force acting on the solid particulates, and continues to support the rotation and load of the shaft member. Note that the rolling elements and the inner and outer rings of the rolling bearing, or the shaft member of the sliding bearing are formed of various steels made of a soft magnetic material having mechanical strength.
On the other hand, ferrous naphthenate in the manufacturing method of the present lubricant is pyrolyzed at 340 ° C. in an atmospheric atmosphere to become ferrous oxide FeO. Further, when the temperature rise rate is suppressed to 380 ° C., a part of the divalent iron ion Fe ²⁺ constituting the ferrous oxide FeO is oxidized to become the trivalent iron ion Fe ³⁺ to become Fe ₂ O. ₃ and the composition formula of FeO · Fe ₂ O ₃ becomes magnetite Fe ₃ O ₄ . Furthermore, when left at 380 ° C. for a certain period of time , all of the divalent iron ions Fe ²⁺ in the ferrous oxide FeO are oxidized to trivalent iron ions Fe ³⁺ , and become ferric oxide Fe ₂ O ₃ to undergo an oxidation reaction. Finish. This ferric oxide Fe ₂ O ₃ is maghemite γ-Fe ₂ O ₃ which is a gamma phase of ferric oxide Fe ₂ O ₃ which is a cubic system similar to magnetite Fe ₃ O ₄ . The crystal structure of hematite α-Fe ₂ O ₃ is an alpha-phase ferric oxide Fe ₂ O ₃ is a trigonal, the magnetite crystal structures are different.
Thus, ferrous naphthenate is thermally decomposed in an organic compound, a granular particulate ferrous oxide FeO precipitated and oxidizing the particulate particles of ferrous oxide FeO, granular magnetite Fe ₃ O ₄ Fine particles are generated. Moreover, when oxidizing the granular particles of magnetite _Fe 3 _{O 4,} the granular particles of maghemite _γ-Fe 2 _{O 3} is generated. For this reason, ferrous naphthenate is a raw material for producing magnetite granular fine particles and maghemite granular fine particles .
That is, ferrous naphthenate is a complex in which the oxygen ion O ⁻ constituting the carboxyl group of naphthenic acid becomes a ligand, and is coordinated to the iron ion Fe ²⁺ by approaching the iron ion Fe ²⁺ . That is, since the oxygen ion O ⁻ approaches the iron ion Fe ²⁺ , which is the largest ion, and is coordinated, the distance between the two becomes short. As a result, the distance between the oxygen ion O ⁻ coordinated to the iron ion Fe ²⁺ and the ion covalently bonded on the opposite side of the iron ion is the longest . When ferrous naphthenate having such molecular characteristics exceeds the boiling point of the main component of naphthenic acid, the oxygen ion O ⁻ constituting the carboxyl group in ferrous naphthenate is on the opposite side of the iron ion Fe ^2+. A bonded portion with a covalently bonded ion is first divided and decomposed into ferrous oxide FeO and naphthenic acid, which are compounds of iron ions Fe ²⁺ and oxygen ions O ⁻ . When the temperature is further increased, naphthenic acid takes the heat of vaporization and vaporizes, and when the vaporization of naphthenic acid is completed, ferrous oxide FeO is precipitated and thermal decomposition is completed. Naphthenic acid is a mixture of saturated fatty acids having a 5-membered ring, represented by a general formula consisting of C _n H _2n-1 COOH, the main component consisting of C ₉ H ₁₇ COOH having a boiling point of 268 ° C. and a molecular weight of 170. .
Note that ferrous naphthenate is an inexpensive industrial chemical that can be easily synthesized. That is, when naphthenic acid, which is a general-purpose organic acid, is reacted with an alkali metal, an alkali metal naphthenate is produced, and when an alkali metal naphthenate is reacted with an inorganic iron compound, ferrous naphthenate is synthesized. The In addition, since naphthenic acid has a low boiling point among organic acids, ferrous naphthenate is thermally decomposed at a temperature of about 340 ° C. in the air atmosphere, and ferrous oxide FeO is precipitated . Such ferrous naphthenate is widely used in paint / printing ink dryers, rubber / tire adhesives, lubricant extreme pressure agents, polyester curing agents, combustion aids and polymerization catalysts. Yes .
As explained above, in the manufacturing method of the present lubricant, ferrous naphthenate becomes an inexpensive raw material for producing granular fine particles of magnetite and maghemite.
Magnetite and maghemite produced through pyrolysis of ferrous naphthenate are produced by oxidation of ferrous oxide granular fine particles, and are not fine particles but granular particles. The granular fine particles have many advantages described below compared with the acicular fine particles. That is, according to the conventional technique, when air is sent to an alkaline aqueous solution of ferrous sulfate or ferric sulfate and reacted, acicular fine particles of ferric hydroxide α-FeO (OH) called goethite are precipitated. . The goethite, once dried over an atmosphere of hydrogen gas and hematite α-Fe ₂ O _3, further reduced to produce the acicular magnetite particles. Thereafter, when the magnetite fine particles are slowly heated and oxidized in the air, the fine particles of acicular magnet are generated. The acicular fine particles do not slip by themselves when subjected to stress, and thus do not have self-lubricating properties. In addition, it is difficult to disperse the needle-shaped particles uniformly in the lubricant because it is difficult to release the magnetic adsorption of the needle-shaped fine particles having almost no mass when the needle-shaped fine particles approach each other. become. Furthermore, the production process for producing needle-shaped fine particles of magnetite and maghemite is more than the production process for producing granular fine particles of magnetite and maghemite via pyrolysis of ferrous naphthenate. A complicated manufacturing process is required and the manufacturing cost is high.
Furthermore, magnetite Fe ₃ O ₄ or maghemite γ-Fe ₂ O ₃ in the production method of the present lubricant has the following four properties, and this brings about an epoch-making action and effect .
First, both magnetite and maghemite have a kind of ferrimagnetic property, which is a hard magnetism. For this reason, when the rolling element of the rolling bearing and the inner ring and the outer ring or the shaft member of the sliding bearing is made of a soft magnetic material, the rolling element and the raceway surface are divided into granular fine particles made of magnetite or maghemite having spontaneous magnetization. Or magnetic shaft force between the shaft member and the magnetite or maghemite granular fine particles having almost no mass, and spherical fine particles comprising an organic compound having almost no mass and a lubricating oil. Does not fall off due to the magnetic attractive force acting on the particulate particles. Since rolling elements, inner rings, and outer rings of rolling bearings are repeatedly subjected to large loads, high carbon chrome steel and martensitic stainless steel with high corrosion resistance are used from the viewpoint of durability. It is a magnetic material. In addition, the shaft member of the sliding bearing includes carbon steel of mechanical structure carbon steel of S25C to S45C having a carbon content of 0.25 wt% to 0.45 wt%, or carbon steel or nickel chrome steel having a carbon content of 0.45 wt% or more. Alloy steels such as nickel chrome molybdenum steel, chrome steel, and chrome molybdenum steel are used, all of which are soft magnetic materials .
Secondly, the magnetic curie point of magnetite is 585 ° C, and the magnetic curie point of maghemite is 675 ° C. Maghemite undergoes phase transition to hematite α-Fe ₂ O ₃ , which is the α phase of ferric oxide, at a temperature of 450 ° C. or higher in the atmosphere . This phase transition is an irreversible change. Therefore, even at a high temperature at which the base oil of the lubricating oil evaporates, the hard magnetic properties of magnetite and maghemite do not change .
Third, magnetite has a Mohs hardness of 5.5 and maghemite has a Mohs hardness of 6.0, both of which are hard particulate particles. Therefore, when the rolling element rolls on the raceway surface, or when the shaft member slides on the sliding surface of the bearing member, the particulate fine particles of magnetite or maghemite are not destroyed even when subjected to shearing force or compressive stress. At this time, when the granular fine particles are in contact with each other, they exhibit self-lubricating properties that they slip. Further, when the granular fine particles are in contact with the liquid spherical fine particles, the liquid spherical fine particles preferentially slide due to the self-lubricating action. Further, when a static load is applied by the shaft member, the particulate fine particles are not destroyed, and the size of the three types of fine particles is determined by the surface roughness between the rolling elements and the raceway surface, or between the bearing member and the shaft member. Since it is smaller than the surface roughness by one digit or more, the three kinds of fine particles exhibit self-lubricating properties and continue to support the static load, and when there are no rolling elements and raceway surfaces, the sliding surfaces of the bearing members do not fatigue .
Fourth, both magnetite and maghemite are stable iron oxides that are not easily corroded, and continue to support the rotation and load of the shaft member in the bearing device without being corroded .
On the other hand, any one of esters of carboxylic acid consisting of unsaturated carboxylic acid, esters of carboxylic acid consisting of aromatic carboxylic acid, or esters of carboxylic acid consisting of dicarboxylic acid in the production method of the present lubricant. Since organic compounds belonging to various types of carboxylic acid esters have five properties, organic compounds serve as raw materials for lubricants, and in bearing devices, spherical particles of organic compounds are formed in a film made up of fine particles. Configure .
In other words, it belongs to any one of carboxylic acid esters of carboxylic acid esters of unsaturated carboxylic acids, carboxylic acid esters of aromatic carboxylic acids, or carboxylic acid esters of dicarboxylic acids. An organic compound having the five properties in the manufacturing method of the present lubricant exists in the organic compound. Such an organic compound is a raw material for the lubricant in the present production method, and in the bearing device, it forms liquid spherical fine particles in a film made up of a collection of fine particles. Such organic compounds are general-purpose industrial chemicals .
Namely, esters of carboxylic acid consisting of unsaturated carboxylic acid, esters of carboxylic acid consisting of aromatic carboxylic acid, or esters of carboxylic acid consisting of esters of carboxylic acid consisting of dicarboxylic acid Because organic compounds belonging to the group have the property of dissolving or mixing in alcohol, mixing organic compounds with alcohol dispersions in which ferrous naphthenate is dispersed in alcohol results in uniform mixing of ferrous naphthenate and organic compounds. . Furthermore, esters of carboxylic acids made of unsaturated carboxylic acids, esters of carboxylic acids made of aromatic carboxylic acids, or esters of carboxylic acids of any one of carboxylic acids made of dicarboxylic acids Since organic compounds belonging to the above have a higher viscosity than alcohol, spherical fine particles having viscosity are formed on the rolling elements and the raceway surface, or on the sliding surfaces of the bearing member and the shaft member. Self-lubricating effect is demonstrated by sliding on itself without being crushed .
Furthermore, esters of carboxylic acids made of unsaturated carboxylic acids, esters of carboxylic acids made of aromatic carboxylic acids, or esters of carboxylic acids of any one of carboxylic acids made of dicarboxylic acids The organic compound belonging to the above has a boiling point higher than 380 ° C. at which magnetite or maghemite fine particles are produced. For this reason, when the above-mentioned mixed solution is heat-treated in the atmosphere, alcohol is first vaporized, and fine crystals of ferrous naphthenate are uniformly deposited on the organic compound. When the temperature is further increased to 340 ° C., ferrous naphthenate is thermally decomposed, and particulate fine particles having a size of 40-60 nm of ferrous oxide FeO are uniformly deposited in the organic compound. Further, when heated to 380 ° C. to suppress the Atsushi Nobori rate, a portion of the divalent iron ions ^{Fe 2+} constituting a ferrous oxide FeO becomes iron ions ^{Fe 3+} trivalent been oxidized _Fe 2 O becomes _3, composition formula granular particles are generated consisting of the size of 40-60nm magnetite _Fe 3 _{O 4} of FeO · _Fe 2 _{O 3.} Further, when left at 380 ° C. for a certain period of time , all of the divalent iron ions Fe ²⁺ in the ferrous oxide FeO are oxidized to trivalent iron ions Fe ³⁺ , and the maghemite γ-Fe ₂ O ₃ has a size of 40-60 nm. The granular fine particle which consists of this is produced | generated. As a result, a collection of particulate fine particles made of magnetite or maghemite is uniformly deposited in the organic compound, and further, when a lubricating oil is mixed and stirred, a suspension serving as a lubricant is created .
In addition, esters of carboxylic acids consisting of unsaturated carboxylic acids, esters of carboxylic acids consisting of aromatic carboxylic acids, or esters of carboxylic acids consisting of carboxylic acid esters consisting of dicarboxylic acids The organic compound belonging to the above has a property that the melting point is lower than the lowering point of the pour point of the lubricating oil. For this reason, even if the bearing device is operated at the lowering point of the pour point of the lubricating oil, the spherical fine particles of the organic compound support the rotation and load of the shaft member without deteriorating the low temperature startability of the shaft member .
Furthermore, esters of carboxylic acids made of unsaturated carboxylic acids, esters of carboxylic acids made of aromatic carboxylic acids, or esters of carboxylic acids of any one of carboxylic acids made of dicarboxylic acids Organic compounds belonging to the group have the property of being incompatible with the lubricating oil. As a result, the organic compound and the lubricating oil in the lubricant constitute spherical fine particles that do not collapse even when subjected to stress. Have sex .
Therefore, when an organic compound belonging to carboxylic acid esters is mixed with an alcohol dispersion obtained by dispersing ferrous naphthenate in alcohol in the production method of the present lubricant, ferrous naphthenate and carboxylic acid ester are mixed in the alcohol. It becomes a mixed solution in which the organic compound belonging to the class is uniformly mixed. This mixed solution is heat-treated in the atmosphere. When the temperature is raised to 340 ° C. after vaporizing the alcohol, ferrous naphthenate is thermally decomposed, and particulate fine particles of ferrous oxide FeO are uniformly deposited in the organic compound belonging to the esters of carboxylic acid. Further, when the temperature rise rate is suppressed to 380 ° C., a part of the divalent iron ion Fe ²⁺ constituting the ferrous oxide FeO is oxidized to become the trivalent iron ion Fe ³⁺ to become Fe ₂ O. _Thus , granular fine particles of magnetite Fe ₃ O ₄ having a composition formula of FeO · Fe ₂ O ₃ are generated. Further, when left at 380 ° C. for a certain period of time , all of the divalent iron ions Fe ²⁺ in the ferrous oxide FeO are oxidized to trivalent iron ions Fe ^3+, and maghemite which is a gamma phase of ferric oxide Fe ₂ O _3. Granular fine particles of γ-Fe ₂ O ₃ are generated. As a result, a collection of particulate fine particles made of magnetite or maghemite is uniformly deposited in the organic compound belonging to the esters of carboxylic acid. When a lubricating oil is mixed with an organic compound belonging to the esters of carboxylic acid and stirred, a suspension serving as a lubricant is prepared. When this lubricant is applied to a bearing device, carboxylic acid esters form liquid spherical fine particles in a film composed of three kinds of fine particles .
As described above, esters of carboxylic acids composed of unsaturated carboxylic acids having five properties, esters of carboxylic acids composed of aromatic carboxylic acids, or esters of carboxylic acids composed of dicarboxylic acids The organic compound belonging to any of the esters of carboxylic acid is a raw material for the lubricant, and in the bearing device, it forms liquid spherical fine particles in a film made up of three kinds of fine particles .
Coating consisting of a mixture of 3 types of microparticles noted previously, has an extremely large ratio of surface area to thickness, the temperature rise of the rolling element and the raceway surface, or, the Atsushi Nobori of the sliding surface of the bearing member and the shaft member Demonstrate cooling effect. On the other hand, even if the bearing device operates at a high temperature for a long time and the low-volatile component of the lubricating oil evaporates, the coating made of a mixture of three kinds of fine particles continues to support the rotation and load of the shaft member. Even if the bearing device operates at a high temperature for a longer period of time and much of the lubricating oil evaporates, the boiling point of the organic compound belonging to the esters of carboxylic acid is over 380 ° C. A film made of a mixture of compound spherical particles continues to support the rotation and load of the shaft member. Even if the bearing device is operated at a high temperature for a long time and the organic compound with a high boiling point evaporates, the particulate fine particles of the metal oxide that do not lose the spontaneous magnetization even at 400 ° C. or higher are magnetically adsorbed to form a multilayer structure. Since the magnetic adsorption force is weak and the granular fine particles exhibit self-lubricating properties, the magnetically adsorbed multilayer structure exhibits self-lubricating properties due to the granular fine particles, and permanently supports the rotation and load of the shaft member. Thus, the fine particles having a self-lubricating action permanently support the rotation and load of the shaft member between the rolling elements and the raceway surface or between the sliding surfaces of the shaft member and the bearing member.
The lubricating oil used in the bearing device is a paraffinic base oil having a carbon number of C15-C50, a molecular weight of 200-700, and a boiling point in the range of atmospheric pressure of 250-600 ° C. Ranges from -10 ° C to -25 ° C. Further, in a bearing device for automobile parts, the track surface or the sliding surface may be heated up to 250 ° C. when continuous high-temperature operation continues. However, in the bearing device, the raceway surface or the sliding surface is rarely heated to a temperature at which much of the base oil constituting the lubricating oil evaporates.
On the other hand, even when the bearing device is operated at a temperature lower than the pour point of the lubricating oil, the melting point of the organic compound belonging to the esters of carboxylic acid is -40 ° C. or lower, and it is lowered by the pour point depressant of the lubricating oil. Since it is lower than the pour point, the coating made of a mixture of three kinds of fine particles continues to support the rotation and load of the shaft member without deteriorating the low temperature startability of the shaft member. Therefore, if the temperature is higher than the freezing point of the organic compound belonging to the esters of carboxylic acid, the coating made of a mixture of three kinds of fine particles can reduce the rotation and load of the shaft member without deteriorating the low temperature startability of the shaft member. Continue to support. Note that the bearing device is rarely operated at a temperature lower than the pour point at which the lubricant has dropped.
Further, the self-lubricating action of the liquid spherical fine particles is not affected by the viscosity of the liquid. That is, even when the viscosity of the organic compound belonging to the carboxylic acid ester and the lubricating oil becomes low at high temperature, the spherical fine particles exhibit self-lubricating properties , and the organic compound belonging to the carboxylic acid ester and the lubricating oil at low temperature Even when the viscosity of the spherical particles increases, the spherical fine particles exhibit self-lubricating properties.
Further, the three types of fine particles always exhibit self-lubricating properties regardless of the rotational speed of the shaft member. Further, even if the shaft member applies a static load to the rolling element and the raceway surface, or the sliding surface of the bearing member, the size of the three kinds of fine particles depends on the surface roughness of the rolling element and the raceway surface, or Since the surface roughness of the bearing member and the shaft member is at least an order of magnitude smaller, the collection of three types of fine particles is self-lubricating on the surface of the rolling element and the raceway surface or on the sliding surface of the bearing member and the shaft member. If it continues to support the static load and the rolling elements and the raceway surface are absent, the sliding surface of the bearing member will not be fatigued.
As described above, the that lubricant to the manufacturing process, and applying at least one of the raceway surface or rolling element of a rolling bearing device, or, simply applied to the slip surface of the shaft member of the sliding bearing device In addition, a bearing device based on a completely new mechanism in which a film composed of a collection of three kinds of fine particles having self-lubricating properties permanently supports the rotation and load of the shaft member has been realized. As a result, the lubricant having the three properties described in paragraph 9 is formed as a film on the rolling element and the raceway surface of the rolling bearing device or on the sliding surface of the bearing member and the shaft member of the sliding bearing device. As a result, the problems of the conventional bearing device can be fundamentally solved, and an innovative bearing device having versatility can be realized.

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The figure which illustrates typically the membrane | film | coat structure which consists of a collection of three types of microparticles | fine-particles.

Embodiment 1
This embodiment is first dissolved or mixed in alcohol, secondly has a higher viscosity than alcohol, thirdly has a boiling point higher than 380 ° C., and fourthly has a melting point lower than the pour point of the lubricating oil, Fifth, an embodiment of an organic compound having these five properties that is incompatible with paraffinic oil. In addition, the pour point of the paraffinic oil which is the base oil of the lubricating oil is −10 ° C. to −25 ° C. In such organic compounds, esters of higher molecular weight carboxylic acid is present.
The esters of carboxylic acid include a first ester composed of a saturated carboxylic acid, a second ester composed of an unsaturated carboxylic acid, a third ester composed of an aromatic carboxylic acid, and two carboxyl groups. And a fourth ester composed of a dicarboxylic acid having

Esters composed of saturated carboxylic acid is first esters, esters of acetic acid, esters of propionic acid, esters of butyric acid, esters of Bibarin acid, esters of caproic acid, esters of caprylic acid, esters of capric acid, esters of lauric acid, esters of myristic acid, esters of palmitic acid, and the like esters of stearic acid.
Boiling point higher than 380 ° C., and dissolved or mixed in alcohols, esters of viscosity than alcohol higher carboxylic acids are esters of stearic acid having a molecular weight of more than butyl stearate. The boiling point of butyl stearate is 389 ° C., but the melting point is as high as 18 ° C., and the boiling point of octyl stearate is 432 ° C., but the pour point is as high as 7 ° C. Accordingly, esters composed of saturated carboxylic acids having a high melting point are not suitable as organic compounds constituting the lubricant.

Then, the esters composed of unsaturated carboxylic acid, esters of acrylic acid, esters of crotonic acid, esters of methacrylic acid, and esters of oleic acid.
Among above the boiling point is 380 ° C., and dissolved or mixed in alcohols, esters from higher viscosity carboxylic acid alcohols are esters of oleic acid having a molecular weight of more ethyl oleate. Incidentally, the boiling point of ethyl oleate is 386 ° C. and the melting point is −32 ° C., and the boiling point of butyl oleate is 415 ° C. and the melting point is −55 ° C. Note esters oleic acid, incompatible with paraffin oil.

In addition, the esters of an aromatic carboxylic acid, there are esters of benzoic acid and esters of phthalic acid. Boiling point higher than 380 ° C., and dissolved or mixed in alcohols, esters of viscosity than alcohol higher carboxylic acids are esters of phthalic acid with bis (2-ethylhexyl) phthalate or more molecular weight. Incidentally, bis (2-ethylhexyl) phthalate has a boiling point of 385 ° C. and a melting point of −55 ° C., and diisononyl phthalate has a boiling point of 403 ° C. and a melting point of −45 ° C. Incidentally, esters phthalic acid, incompatible with paraffin oil.

Further, the esters composed of dicarboxylic acids include esters with dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, spellic acid, azelaic acid, sebacic acid and fumaric acid. . Esters having a boiling point higher than 380 ° C., dissolved or mixed in alcohol, and higher in viscosity than alcohol are sebacic acid esters having a molecular weight equal to or higher than dioctyl sebacate. Incidentally, dioctyl sebacate has a boiling point of 435 ° C. and a melting point of −48 ° C. Incidentally, esters of sebacic acid is not compatible with paraffin oil.
As described above, esters of carboxylic acids consisting of unsaturated carboxylic acids, or esters of carboxylic acids comprising an aromatic carboxylic acid, or any of the carboxylic acid esters of carboxylic acids consisting of a dicarboxylic acid Among the organic compounds belonging to these esters, there are organic compounds having the five properties described in paragraph 23.

Example 1
In this example, a lubricant comprising a suspension in which granular fine particles of magnetite are dispersed in an organic compound and a lubricating oil is prepared. Ferrous naphthenate (for example, a product of Toei Chemical Co., Ltd.) was used as a raw material for magnetite. Butyl oleate (for example, a product of Junsei Co., Ltd.) was used as the organic compound. Butyl oleate is miscible with methanol, has a viscosity 8.6 times that of methanol, has a density of 0.87 g / cm ³ , a boiling point of 415 ° C., a melting point of −55 ° C. and is not compatible with paraffinic oil. . Moreover, Daphne Mechanic Oil 10 of Idemitsu Kosan Co., Ltd. was used as the lubricating oil. This lubricating oil has the properties that the base oil is a paraffinic oil, the density is 0.899 g / cm ³ , the kinematic viscosity at 40 ° C. is 10.0 mm ² / s, and the pour point is −40 ° C. or less.
First, magnetite fine particles are deposited on butyl oleate. For this reason, 200 grams corresponding to 0.5 mole of iron naphthenate was dispersed in methanol as 10% by weight, and 42.5 grams corresponding to 0.125 mole of butyl oleate was mixed with this methanol dispersion. This mixed solution is heat-treated in the atmosphere. First, the mixture was heated to 65 ° C. to vaporize methanol, and fine crystals of iron naphthenate were uniformly deposited on butyl oleate. Next, the mixed solution was 40 ° C./min. The temperature was raised to 340 ° C. at a heating rate of 340 ° C. and allowed to stand at 340 ° C. for 5 minutes to thermally decompose iron naphthenate, and particulate fine particles of ferrous oxide FeO were uniformly deposited on butyl oleate. Thereafter, 1 ° C./min. The temperature was raised to 380 ° C. at a heating rate of 380 ° C. and left at 380 ° C. for 2 minutes to oxidize ferrous oxide FeO to magnetite Fe ₃ O ₄ and 0.5 mol in 0.125 mol butyl oleate. A collection of granular fine particles of magnetite corresponding to was uniformly deposited. Next, 44 g of lubricating oil was mixed with the heat-treated mixed solution, and a lubricant 1 was prepared by applying ultrasonic vibration of 20 kHz to the mixed solution for 30 seconds using an ultrasonic homogenizer (product of Nippon Emerson Co., Ltd.). Further, a part of the lubricant 1 was taken out, and 20 kHz ultrasonic vibration was added to the suspension 1 for 5 minutes to prepare the lubricant 2. Further, the lubricant 2 was taken out, and 20 kHz ultrasonic vibration was added to the lubricant 2 for 10 minutes to prepare the lubricant 3.
The ultrasonic vibration homogenizer is an apparatus for making particles fine using tiny bubbles (cavitation) as described in the 11th paragraph, and the particles are made fine in a short time.

Next, the film structure formed by the three types of lubricants prepared was observed with an electron microscope. For this reason, three types of lubricants are printed on a 5 cm × 5 cm aluminum plate with a width of 1 cm, a length of 5 cm and a thickness of 10 μm, and an aluminum plate of 5 cm × 5 cm is overlaid thereon, and a weight of 1 kg is further provided. And then left at 100 ° C. for 10 minutes, the coated surface coated with the lubricant was cut, and the cut surface of the lubricant was observed with an electron microscope. The electron microscope used was an ultra-low acceleration voltage SEM from JFE Techno-Research Corporation. This apparatus is capable of observing the surface with an extremely low acceleration voltage from 100 V, and has a feature that the surface of the sample can be directly observed without forming a conductive film.
First, an extremely low acceleration voltage of 100 V was applied to observe the cut surfaces of the three types of lubricants. As a result, all the lubricants form a film having a thickness of 10 μm in the gaps between the aluminum plates. This film consists of a collection of particles of about 2 μm in the lubricant 1, and spherical fine particles of about 0.2 μm in the lubricant 2. Similarly, it was found that the lubricant 3 is similarly composed of a collection of spherical fine particles of about 0.2 μm, and that each coating has an infinite number of smaller fine particles dispersed therein.
Next, the secondary electron beam between 900-1000 V of the reflected electron beam was taken out and subjected to image processing, and smaller particles were observed. As a result, the smaller particles were granular particles having a size of 40-60 nm.
Further, the granular fine particles having a size of 40 to 60 nm were subjected to image processing by extracting energy between 900 to 1000 V of the reflected electron beam, and the material of the fine particles was observed by the density of the image. Since light and shade were observed, it was found that the film was formed from multiple types of elements.
Next, the energy of the characteristic X-ray and its intensity were image-processed to analyze the elements. The granular fine particles are iron oxide because both iron atoms and oxygen atoms are present uniformly and no unevenly distributed portions are observed. Furthermore, an EBSP analysis function was added to the SEM function to analyze the crystal structure. As a result, granular particles were confirmed to be magnetite Fe ₃ O _4. The EBSP analysis function means that when a sample is irradiated with an electron beam, reflected electrons are diffracted by the atomic plane in the sample to form a band-like pattern, and the symmetry of this band corresponds to the crystal system. Since the band interval corresponds to the atomic plane interval, analyzing this pattern means analyzing the crystal orientation and crystal system.
From these results, it was found that the refinement of the particles of butyl oleate and the lubricating oil proceeded in a short time by the ultrasonic homogenizer, and the refinement of the particles was finished at 0.2 μm. The particle pulverization by shock waves in this ultrasonic homogenizer corresponds to a phenomenon in which particles are pulverized by shearing stress or compression stress applied to the lubricant in the bearing device. Therefore, in the bearing device, butyl oleate and lubricating oil become 0.2 μm spherical fine particles, and the 0.2 μm spherical fine particles do not become finer particles even when subjected to stress. It exhibits self-lubricating properties that relieve stress. Moreover, since the boiling point of the substance constituting the lubricant is high, the thickness at the time of printing becomes the thickness of the film as it is. Therefore, in the bearing device, a film corresponding to the amount of applied lubricant is formed on at least one of the rolling elements or the raceway surface, or at least one of the bearing member or the shaft member.
A part of the film structure formed by the lubricants 2 and 3 prepared in this example is schematically shown in an enlarged manner in FIG. Lubricants 2 and 3 form film 1, which is uniform throughout the collection of 0.2 μm spherical fine particles 2 made of butyl oleate and 0.2 μm spherical fine particles 3 made of lubricating oil. And 40 to 60 nm granular fine particles 4 dispersed in magnetite.

Example 2
In this example, a lubricant composed of a suspension in which particulate fine particles of maghemite are dispersed in an organic compound and a lubricating oil is prepared. The raw material for maghemite was ferrous naphthenate of Example 1. As the organic compound, butyl oleate of Example 1 was used. As the lubricating oil, Daphne Mechanic Oil 10 of Idemitsu Kosan Co., Ltd. of Example 1 was used.
First, particulate maghemite particles are deposited on butyl oleate. Therefore, 200 grams corresponding to 0.5 mole of ferrous naphthenate was dispersed in methanol as 10% by weight, and 42.5 grams corresponding to 0.125 mole of butyl oleate was mixed with this methanol dispersion. did. This mixed solution is heat-treated in the atmosphere. First, the mixture was heated to 65 ° C. to vaporize methanol, and fine crystals of iron naphthenate were uniformly deposited on butyl oleate. Next, 40 ° C./min. The temperature was raised to 340 ° C. at a heating rate of 340 ° C. and allowed to stand at 340 ° C. for 5 minutes to thermally decompose iron naphthenate, and particulate fine particles of ferrous oxide FeO were uniformly deposited on butyl oleate. Thereafter, 1 ° C./min. The temperature was raised to 380 ° C. at a heating rate of 380 ° C. and left at 380 ° C. for 30 minutes to oxidize ferrous oxide FeO to maghemite γ-Fe ₂ O ₃ , and in 0.125 mol of butyl oleate, 0. A collection of granular fine particles of maghemite corresponding to 5 mol was uniformly deposited. Next, 44 grams of lubricating oil was mixed with the heat-treated mixed solution, and ultrasonic vibration of 20 kHz was added to the mixed solution for 30 seconds using an ultrasonic homogenizer in the same manner as in Example 1 to prepare Lubricant 4. Furthermore, a part of the lubricant 4 was taken out, and 20 kHz ultrasonic vibration was added to the suspension 4 for 5 minutes to prepare the lubricant 5. Further, the lubricant 5 was taken out, and 20 kHz ultrasonic vibration was added to the lubricant 5 for 10 minutes to prepare the lubricant 6.

Next, the film structure formed by the prepared three types of lubricants was observed with an electron microscope in the same manner as in Example 1. Three types of lubricants were printed at a thickness of 10 μm in the gaps between the aluminum plates, the coated surfaces coated with the respective lubricants were cut, and the cut surfaces of the lubricants were observed with an electron microscope.
First, an extremely low acceleration voltage of 100 V was applied to observe the cut surfaces of the three types of lubricants. As a result, all the lubricant forms a film having a thickness of 10 μm in the gap between the aluminum plates. This film is made up of a collection of particles of about 2 μm in the lubricant 4 and spherical fine particles of about 0.2 μm in the lubricant 5. Similarly, it was found that the lubricant 6 is similarly composed of a collection of spherical fine particles of about 0.2 μm, and that each coating has an infinite number of smaller fine particles dispersed therein.
Next, the secondary electron beam between 900-1000 V of the reflected electron beam was taken out and subjected to image processing, and smaller particles were observed. As a result, the smaller particles were granular particles having a size of 40-60 nm.
Further, the granular fine particles having a size of 40 to 60 nm were subjected to image processing by extracting energy between 900 to 1000 V of the reflected electron beam, and the material of the fine particles was observed by the density of the image. Since light and shade were observed, it was found that the film was formed from multiple types of elements.
Next, the energy of the characteristic X-ray and its intensity were image-processed to analyze the elements. The particulate fine particles are iron oxide because both iron atoms and oxygen atoms are present uniformly and no unevenly distributed portions are observed. Furthermore, an EBSP analysis function was added to the SEM function to analyze the crystal structure. As a result, it was confirmed that the granular fine particles were maghemite γ-Fe ₂ O ₃ .
From this result, the miniaturization of the particles by the ultrasonic homogenizer was completed with spherical fine particles of 0.2 μm as in Example 1. Therefore, as in Example 1, in the bearing device, butyl oleate and lubricating oil become 0.2 μm spherical fine particles, and the 0.2 μm spherical fine particles do not become finer particles even under stress, It has self-lubricating properties that relieve stress by sliding itself. Note that the coating structure of the lubricants 5 and 6 is the same as that shown in FIG.

Example 3
Next, using a three-ball rolling fatigue tester (a product of Fuji Testing Machine Co., Ltd.), applying lubricant to the rolling elements delays the occurrence of scratches on the raceway surface due to rolling fatigue. I investigated. This testing machine places three steel balls corresponding to rolling elements on a disk corresponding to the raceway surface, rotates these steel balls, applies a load to the disk, and causes rolling fatigue due to point contact. Add continuously to the disc. When scratches such as pitching and flaking occur on the disc, the vibration acceleration sensor installed on the lever to which the load is applied detects the vibration due to the scratch and stops the testing machine. As the material for the disc and the steel ball, high-carbon chromium bearing steel, which is generally used for the raceway surface and rolling elements, was used. In comparison with the case where the surface of the three steel balls was coated with a lubricant and the case where a lubricant was not applied, the effect of delaying the time when the disk was damaged due to the self-lubricating property of the lubricant was investigated. As the lubricant, the lubricant 3 prepared in Example 1 and the lubricant 6 prepared in Example 2 were used, and applied to steel balls 5 times each, and the test was performed 10 times.
The initial test conditions were a load of 100 kgf and a rotation speed of 1000 rpm. When the test temperature was 200 ° C., the test apparatus stopped in only 6 hours when no lubricant was applied. On the other hand, when the lubricant 3 and the lubricant 6 were applied, the operation time was extended to 48-50 hours. When the test temperature was room temperature, when the lubricant was not applied, the test apparatus stopped in only 10 hours, whereas when the lubricant was applied, the test was stopped halfway because it operated even for 100 hours. At the test temperature of −30 ° C., when the lubricant was not applied, it was only 5 hours, whereas when the lubricant was applied, the operation time was extended to 40-42 hours.
Next, the test conditions were a load of 550 kgf and a rotation speed of 2000 rpm. When the test temperature was 200 ° C., the test apparatus stopped in only 4 hours when no lubricant was applied. On the other hand, when the lubricant 3 and the lubricant 6 were applied, the operation time was extended to 40-45 hours. When the test temperature was room temperature, when the lubricant was not applied, the test apparatus stopped in only 6 hours, whereas when the lubricant was applied, the operation time was extended to 84 to 86 hours. At the test temperature of −30 ° C., when the lubricant was not applied, the time was only 3 hours, whereas when the lubricant was applied, the operation time was extended to 36-38 hours.
Further, the test conditions were that the load was increased to 1000 kgf and the rotation speed was increased to 3000 rpm. When the test temperature was 200 ° C., the test apparatus stopped in only 2 hours when no lubricant was applied. On the other hand, when the lubricant 3 and the lubricant 6 were applied, the operation time was extended to 26 to 28 hours. When the test temperature was room temperature, when the lubricant was not applied, the test apparatus stopped in only 3.5 hours, whereas when the lubricant was applied, the operation time was extended to 52-55 hours. At the test temperature of −30 ° C., when the lubricant was not applied, it was only 1.5 hours, whereas when the lubricant was applied, the operation time was extended to 20-23 hours.
From the above results, even when the test temperature is not limited to room temperature, even when the temperature is 200 ° C. and −30 ° C., the load applied to the raceway surface is relieved by the self-lubricating property of the lubricant, and the generation time of scratches due to rolling fatigue is more than 8 times Extended. Also, the greater the load, the faster the rotation speed, the higher the temperature, and the lower the temperature, the greater the effect of the self-lubricating property of the lubricant, and the time when scratches occur when the lubricant is not applied, It was found that when the lubricant was applied, the ratio of the occurrence of scratches increased. Therefore, the load applied to the raceway surface is reduced by the self-lubricating property of the lubricant, and the friction force between the rolling elements and the raceway surface is reduced. The greater the load, the higher the rotational speed, and the higher the temperature. It was proved that the lower the temperature, the larger. For this reason, when lubricant is applied to the sliding contact surface, regardless of whether it is a rolling bearing device or a sliding bearing device, the higher the temperature at which the device is operated and the lower the temperature, the more the load applied to the sliding contact surface. It has been proved that the larger the value of the sliding contact surface, the higher the rotation speed of the sliding contact surface, and the more remarkable the self-lubricating effect by the lubricant appears on the sliding contact surface.

Example 4
Furthermore, using a test device (3T-2000-5000N type in the product of Takachiho Seiki Co., Ltd.) that complies with the ring-to-disk wear test in the plastic sliding wear test (JIS K7218A method 1986), to the bearing member of the slide bearing device The improvement of the baking property and the improvement of the silence due to the application of the lubricant were investigated. In the test using this device, a ring as a bearing member is rotated, a disk as a shaft member is pressed against the rotating ring, the pressing load is increased, and the wear depth of the ring, the friction coefficient, and the progress of friction heat are measured. Measure simultaneously and determine the critical PV value from these data.
The ring was composed of POM resin, the disk was composed of S45C, the ring was rotated at a peripheral speed of 0.5 m / s, and the pressing load was increased at a rate of 20 N every 10 minutes. As a result, when the pressing load reached 160 N, all of the friction coefficient, frictional heat, and friction depth increased rapidly. Therefore, 160 N became the melting load of the ring made of POM resin, and the limit PV value was 400 kPa · m / s.
Next, each of the lubricant 3 and the lubricant 6 was individually applied to the surface of the POM resin, the test apparatus was operated under the same conditions as described above, and the melt load of the ring was obtained. As a result, the melt load increased to 350-380N, the limit PV value increased to 875-950 Pa · m / s, and the quietness of the sliding surface was also increased to 350-380N.
From this result, it was proved that the lubricant having self-lubricating property brings about an effect of further increasing the baking load of the sliding component made of the POM resin excellent in sliding property by more than twice.

1 Coating 2 Spherical Fine Particles of Butyl Oleate 3 Spherical Fine Particles of Lubricating Oil 4 Granular Fine Particles of Magnetite

Claims (1)

A method of manufacturing a lubricant applied to at least one of a raceway surface or a rolling element of a rolling bearing device in which a rolling element, an inner ring, and an outer ring are made of a soft magnetic material, or a bearing of a sliding bearing device in which a shaft member is a soft magnetic material lubricant manufacturing method of imparting at least one of the sliding surfaces of the member or the shaft member, a naphthenate ferrous to deposit ferrous oxide by thermal decomposition dispersed in the alcohol first to create an alcohol dispersion A first property having a melting point lower than the pour point of a lubricating oil composed of a paraffinic base oil, and a second property having a boiling point higher than the temperature at which the ferrous oxide is oxidized to magnetite or maghemite. When, a third nature incompatible with the lubricating oil, a fourth property of dissolving or mixing in the alcohol, Toka fifth nature than the viscosity is high the alcohol Becomes, esters of these five properties consisting unsaturated carboxylic acids having both a carboxylic acid, or esters of carboxylic acids comprising an aromatic carboxylic acid, or any of the esters of carboxylic acids consisting of a dicarboxylic acid A second step in which an organic compound belonging to one kind of carboxylic acid ester is mixed to prepare a mixed solution; and the mixed solution is heat-treated in an air atmosphere to thermally decompose the ferrous naphthenate and Ferrous particulate fine particles are generated, and the temperature is further raised, and the ferrous oxide granular fine particles are oxidized to magnetite or maghemite granular fine particles, and the mixed liquid is made of any one of the materials of magnetite or maghemite. a third step of collection of the particulate particles Ru precipitating made, the mixture was heat-treated at the third step, paraffinic Besuoi Stirring a mixture of lubricating oil consisting of suspension consists of a fourth step of creating a lubricant consisting Nigoeki, producing a lubricant comprising the suspension was carried out continuously these four steps A method for producing a lubricant.

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