JP2007051705A - High-precision plain bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plain bearing of high precision and adhesiveness and high lubricating property, in the plain bearing capable of being used for various purposes. <P>SOLUTION: In this sliding bearing wherein a bearing main body 1 is composed of metal, and its sliding face is coated with a resin layer 2 composed of a resin material, at least the part coated with the resin layer, of the surface of the bearing main body has fine recessed portions, a value of (linear expansion coefficient (°C<SP>-1</SP>) of the resin material)×(thickness (μm) of the resin layer) of the resin layer is 0.15 or less, the total apparent area occupied by the recessed portions is 20-95% as much as the sliding face, and the sliding face is formed on both of an inner peripheral wall surface and an outer surface supporting radial load. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sliding bearing having high accuracy and excellent sliding characteristics.

  Conventionally, a sliding bearing in which a porous sintered metal is impregnated with a lubricating oil is known as a sliding bearing with high rotational accuracy. When this sliding bearing is used by impregnating a sintered metal-based porous material with a lubricating oil, the oil can be continuously supplied to the sliding interface, so that the frictional force can be lowered. . In general, the mating material of the slide bearing is often a metal material, and there is no fear of stiffening or coming off due to a difference in linear expansion. In addition, this metal material can improve the processing accuracy, and is suitable for use in a place where rotational accuracy is required.

  As other plain bearings having self-lubricating properties other than those described above, those in which a solid lubricant such as PTFE, graphite, molybdenum disulfide or the like is blended with a resin, or a lubricant or wax is blended are known.

  Furthermore, the resin material is used in order to minimize the wear of the mating material even when the mating material is a soft material without supplying lubricating oil, and so as not to deteriorate the rotation accuracy. Patent Document 1 discloses a high-accuracy plain bearing in which a resin layer is formed by insert molding on a sliding portion, and a fine recess is provided on the surface of a bearing body that forms the resin layer.

  When the sliding bearing described in Patent Document 1 is used, since the resin material enters the fine recess, the bearing body and the resin layer are joined with high adhesion by the anchor effect, and only the resin layer on the surface is the resin material. Therefore, the dimensional change due to the temperature change is small, and high lubricity can be obtained while maintaining high accuracy.

JP 2003-239976 A

  However, in the high-precision sliding bearing described in Patent Document 1, the sliding surface is only the inner peripheral wall surface of the shaft hole, and the shape of the sliding bearing is limited.

  Accordingly, an object of the present invention is to provide a sliding bearing having high accuracy and adhesion and having high lubricity in a sliding bearing that can be used for various applications.

This invention is a sliding bearing in which the bearing body is made of metal and the sliding surface is covered with a resin layer formed of a resin material,
Of the surface of the bearing body, at least a portion covered with the resin layer has a fine recess,
The value of (linear expansion coefficient of resin material (° C. ⁻¹ )) × (thickness of resin layer (μm)) in the resin layer is 0.15 or less,
The total apparent area occupied by the recess is 20 to 95% of the area of the sliding surface,
The above-described problem has been solved by manufacturing a high-precision sliding bearing in which the sliding surface is provided on both the inner peripheral wall surface and the outer surface that supports a load in the radial direction.

  In other words, not only the inner peripheral wall surface of the shaft hole but also the outer surface, which is the outer surface of the bearing, is provided with a sliding surface, and a fine recess is provided on the sliding surface and covered with a predetermined resin layer so that the outer surface is simply removed. Not only when the diameter is fixed and the inner diameter slides, but also when the bearing is rotated, the inner peripheral wall surface of the bearing slides or the outer surface rotates or slides. The resin layer for exerting the lubricity can be provided with high accuracy. In particular, this sliding bearing can be suitably used as a bearing in a place where slidability is required to support a load in the radial direction on both the inner peripheral wall surface and the outer surface.

  In addition, in bearings that have a cylindrical outer appearance or a quadratic prism appearance, the outer surface of the bearing is a sliding surface, and the sliding surface is covered with a resin layer. It can be a bearing.

  Also, by applying the sliding surface on which the resin layer is provided not only to the inside and outside of the sliding bearing, but also to the end surface between the inside and outside, the same slidability and high accuracy can be achieved when supporting the load in the thrust direction. Can be obtained.

  Moreover, high adhesiveness is realizable between the said resin layer and the said bearing main body by making the average magnitude | size of a recessed part into 5-300 micrometers and an average depth being 3 micrometers or more.

  In addition, if the metal constituting the bearing body is a sintered metal, the concave portion communicates with the inside to form a communication hole. Therefore, when the resin layer is formed, the resin material that has entered the concave portion is formed. The resin layer can be more firmly held on the surface of the bearing body by entering the communication hole.

  Moreover, when lubricating oil or a solid lubricant is mix | blended with a resin material, the lubricity of the sliding surface which consists of the said resin layer can further be improved.

  Furthermore, the high-precision sliding bearing according to the present invention can be suitably used as a photosensitive drum, developing unit and / or fixing unit bearing of a copying machine or a printer, and a carriage shaft bearing.

  Since the high-precision sliding bearing according to the present invention has a sliding function on both the inner and outer surfaces, high lubricity is achieved when the outer surface rotates or slides while the inner peripheral wall surface rotates or slides. It can be realized with accuracy.

  The present invention will be described in detail below. In the high-precision sliding bearing according to the present invention, the bearing body 1 is made of metal, has a shaft hole that penetrates the bearing body 1, and the sliding surface is covered with a resin layer 2 formed of a resin material.

  The sliding surface is a place where the bearing can receive a load in contact with other components such as a shaft and a support, and the high-precision sliding bearing according to the present invention includes at least an inner peripheral wall surface of the shaft hole, The sliding surface is provided on the outer surface that supports the load in the radial direction.

  Examples of such high-precision sliding bearings are shown in FIGS. FIG. 1 (a) shows an end face appearance and FIG. 1 (b) shows a cross section of a plain bearing, in which the appearance of the bearing body 1 is a cylindrical plain bearing, and the resin layer 2a on the inner peripheral wall surface and the outer diameter portion. The inner and outer surfaces are covered with the outer surface resin layer 2b. This sliding bearing can receive a rotational motion or a sliding motion on the resin layer 2a on the inner peripheral wall surface, and can receive a rotational motion on the outer surface.

  2A is a plain bearing in which the outer appearance of the bearing body 1 is a quadrangular prism shape, and the resin layer 2a on the inner peripheral wall surface The inner and outer surfaces are covered with the resin layer 2b on the outer surface. This sliding bearing can receive a rotational motion or a sliding motion on the resin layer 2a on the inner peripheral wall surface, and can receive a sliding motion on the outer surface.

  Furthermore, the high-precision sliding bearing according to the present invention may have a resin layer 2c on the end surface that supports a load in the thrust direction, as shown in FIGS.

  Moreover, the external appearance shape of the bearing body 1 of the sliding bearing according to the present invention is not limited to the shape of FIG. 1 or FIG. 2, but may be a shape in which a cylinder is combined as shown in FIG. .

  The metal material constituting the bearing body 1 is preferably a metal having fine concave portions on its surface as shown in the sectional view shown in FIG. More preferred. In particular, when a sintered metal is used, since the recesses of the sintered metal communicate with each other to form a communication hole, the resin material enters the communication hole when the resin layer 2 is formed with the resin material. And the said bearing main body 1 and the resin layer 2 are hold | maintained more firmly.

  Examples of the material of the sintered metal include Cu-based and Fe-Cu-based materials, and may include C, Zn, Sn, and the like as components. Further, a small amount of a binder may be added in order to improve moldability and releasability. Further, an aluminum-based material containing Cu, Mg, Si, or the like, or a metal-synthetic resin material in which iron powder is bonded with an epoxy-based synthetic resin may be used. Furthermore, in order to improve the adhesion with the resin layer 2, it is possible to perform surface treatment or use an adhesive or the like as long as it does not hinder molding.

  In addition, the said sintered metal can be manufactured through each process of pressure molding, degreasing, baking, and sizing.

  As shown in FIG. 5, fine concave portions are provided on at least the surface portion of the bearing body 1 that contacts the resin layer 2. When the resin layer 2 is formed, the molten resin enters the fine recesses, so that the adhesion between the bearing body 1 and the resin layer 2 can be improved by the anchor effect.

  The total apparent area occupied by the recesses is preferably 20 to 95%, and preferably 40 to 90%, of the area of the surface portion of the bearing body 1 in contact with the resin layer 2. If it is less than 20%, the anchor effect cannot be exhibited and the resin may be easily peeled off. On the other hand, if it exceeds 95%, dimensional accuracy and strength may not be maintained. The apparent area refers to the area occupied by the recess when the surface portion of the bearing body 1 is viewed from above.

  The average size of the recesses is preferably 5 to 300 μm, and more preferably 10 to 250 μm. As shown in FIGS. 6A to 6D, the size of the concave portion represents the maximum length of any two points existing around the concave portion, that is, the absolute maximum length. When the size is less than 5 μm, when the resin layer 2 is formed, the melted resin cannot easily enter the concave portion, so that a sufficient anchor effect cannot be exhibited. On the other hand, when the size exceeds 300 μm, it is difficult to obtain dimensional accuracy and the mechanical strength is extremely lowered. The average size of the recesses can be adjusted by adjusting the particle diameter of the metal particles, the density of the sintered metal, or the dimensions of the sizing mold.

  The average depth of the recess is preferably 3 to 500 μm, and preferably 3 to 300 μm. When the depth is less than 3 μm, when the resin layer 2 is formed, the melted resin cannot easily enter the hole, and thus a sufficient anchor effect may not be exhibited. On the other hand, when the depth is larger than 500 μm, the dimensional accuracy is difficult to obtain and the mechanical strength may be extremely lowered.

  As a method for forming the concave portion on the bearing body 1, for example, a predetermined surface shape can be obtained by machining, sandblasting, etching, transferring unevenness by pressure, or the like. In view of cost, it is preferable to use a sintered metal. Sintered metal is the size and depth of the recesses caused by the gaps between the metal particles by adjusting the particle diameter of the metal particles, the density of the sintered metal, or the dimensions of the sizing mold, molding pressure, firing temperature, etc. The ratio can be optimized, a predetermined surface shape can be obtained without post-processing, and the cost is low.

  The resin layer 2 is formed by molding a resin material on the sliding surface of the bearing body 1, and an example of the molding method is insert molding. The resin material is preferably a material having excellent slidability when the resin layer 2 is formed, and a solid lubricant or lubricating oil can be blended. Examples of such resin materials include polyethylene, polyamide, polyacetal, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyphenylene sulfide, polyethersulfone, polyetherimide, polyamideimide, polyetheretherketone, thermoplastic polyimide, and thermosetting. Include a functional polyimide, an epoxy resin, and a phenol resin.

  An appropriate filler can be added to the resin material used for molding the resin layer 2 in order to improve the friction / wear characteristics and reduce the linear expansion coefficient. Examples include glass fiber, carbon fiber, pitch-based carbon fiber, polyacrylonitrile (PAN) -based carbon fiber, aramid fiber, alumina fiber, polyester fiber, boron fiber, silicon carbide fiber, boron nitride fiber, silicon nitride fiber, metal fiber Fibers such as asbestos and quartz wool, and those knitted into cloth, minerals such as calcium carbonate, talc, silica, clay and mica, inorganic whiskers such as aluminum borate whisker and potassium titanate whisker, carbon black And various heat resistant resins such as graphite, polyimide resin and polybenzimidazole. Furthermore, carbon fiber, metal fiber, graphite powder, zinc oxide, or the like may be added for the purpose of improving the thermal conductivity of the lubricating composition. Furthermore, carbonates such as lithium carbonate and calcium carbonate, and phosphates such as lithium phosphate and calcium phosphate may be blended.

  Examples of the solid lubricant that can be blended in such a resin material include general solid lubricants such as polytetrafluoroethylene, graphite, molybdenum disulfide, boron nitride, tungsten disulfide, spindle oil, refrigerator oil, turbine oil, Examples thereof include mineral oils such as machine oils and dynamo oils, and synthetic oils such as hydrocarbons, esters, polyglycols, silicone oils, and fluorinated oils. It is also possible to impregnate the sintered metal bearing body 1 with these oils and to exude and lubricate the sliding surface through the resin layer. Impregnation can be performed by a method such as vacuum impregnation.

  Moreover, you may use together the additive which can be widely applied to general synthetic resin by the compounding quantity which does not inhibit the effect of this invention. For example, industrial additives such as mold release agents, flame retardants, antistatic agents, weather resistance improvers, antioxidants, and colorants may be added as appropriate, and the method of adding them is not particularly limited. .

  Furthermore, as long as the lubricity of the resin layer 2 of the high-precision sliding bearing according to the present invention is not impaired, the resin layer 2 is separately obtained in the form of the intermediate product or the final product by chemical or physical treatment such as annealing treatment. Modifications are possible to improve the properties.

In the above resin layer 2, the value of (linear expansion coefficient of resin material (unit: ° C. ⁻¹ )) × (thickness of resin layer 2 (unit: μm)) is preferably 0.15 or less, 0.13 The following is preferable, and 0.10 or less is more preferable. When the said value is larger than 0.15, the thickness or expansion | swelling of the resin layer 2 will also become large. At this time, since the outer diameter side of the resin layer 2 on the inner peripheral wall surface of the bearing body 1 is constrained by the metal, it cannot expand more than the expansion of the metal, expands toward the inner diameter side, and the inner diameter dimension is Get smaller. Further, since the inner diameter side of the resin layer 2 on the outer surface or outer diameter surface of the bearing body 1 is constrained by metal, the opposite phenomenon occurs for the same reason, and the resin layer 2 expands to the outer diameter side. As a result, the gap is reduced, and depending on the initial gap setting, there is a possibility that the shaft may be stiff due to the temperature rise. In addition, excessive fluctuation of the gap is not preferable because it causes torque fluctuation. From the viewpoint of rotational accuracy, it is preferable that the gap is small. Moreover, the dimensional change by water absorption also becomes large, and the fluctuation | variation of an excessive gap may arise.

Moreover, the thinnest thickness of the moldable resin layer 2 is about 50 μm, and if it is thinner than this, formation becomes difficult. Accordingly, the above (linear expansion coefficient of resin material (unit: ° C. ⁻¹ )) × (thickness of resin layer 2 (unit: μm)) needs to be 0.003 or more, preferably 0.01 or more. More preferably, 0.015 or more is necessary.

  The high-precision sliding bearing according to the present invention has a bearing body 1 disposed in a mold, and an inner peripheral wall surface and an outer surface that become a sliding portion that supports a load in a radial direction, and, if necessary, a thrust direction bearing. The resin material can be manufactured by insert molding the end surface supporting the load. Specifically, it is manufactured by putting the bearing body 1 in the mold in advance and injecting a molten resin material into a gap between the bearing body 1 and a mold part such as a core pin using a film gate or a side gate. The

  As the shape of the high-precision sliding bearing according to the present invention, an optimum bearing shape can be selected in accordance with the shape of the sliding portion such as a radial type or a flanged bush.

  The place where the resin layer 2 is insert-molded into the bearing body 1 is not particularly limited as long as it is a sliding portion of the bearing body 1. For example, the case of the resin layers 2a-2c shown in FIGS. 1 and 2 show a structure in which a resin layer 2a is formed on the sliding portion of the inner peripheral wall surface of the bearing body 1 and a resin layer 2b is formed on the sliding portion of the outer surface in order to support a load in the radial direction. It is. 3 and 4 show the end surface in addition to the resin layers 2a and 2b of the sliding portion of the inner peripheral wall surface and the sliding surface of the outer surface in order to support the load in the radial direction and the thrust direction. The resin layer 2c is formed on the sliding portion. In addition, you may employ | adopt the shape of the resin layer 2 which has a hook part so that the bearing main body 1 and the resin layer 2 may not peel off.

  The high-precision sliding bearing according to the present invention can reduce the clearance between the bearing and the shaft in order to improve the rotational accuracy of the shaft. At this time, if wear powder is generated by sliding, the wear powder may be interposed in the gap. In this case, the rotational torque may be increased or the abrasion powder may act as an abrasive to cause abnormal wear of the shaft or the bearing.

  As a measure for avoiding the above abnormal wear, the resin layer 2a provided on the sliding portion of the inner peripheral wall surface of the bearing, the resin layer 2b provided on the sliding portion of the outer surface, and the end surface sliding portion for thrust load are provided. A recess can be provided in the resin layer 2c. By providing this recess, wear powder can be captured in this recess and the occurrence of abnormal wear can be suppressed.

  When the concave portion is provided in the resin layer 2a of the sliding portion of the inner peripheral wall surface, the apparent area per concave portion is preferably 0.5 to 10% of the entire inner peripheral wall surface area, and the apparent appearance of the concave portion. The total area is preferably 0.5 to 30% of the entire inner wall surface area.

  Moreover, when providing the said recessed part in the resin layer 2b of the sliding part of an outer surface, 0.5-10% of the total outer surface area is preferable, and the apparent area per recessed part is the apparent area of the said recessed part. The total sum is preferably 0.5 to 30% of the entire outer surface area.

  Furthermore, when providing the said recessed part in the resin layer 2c of the sliding part of an end surface, the apparent area per said recessed part provided in the one side end surface is preferable 0.5 to 10% of the area of the whole one side end surface, and The total apparent area of the recesses provided on the one end face is preferably 0.5 to 30% of the area of the entire one end face.

  In any case, if it is less than 0.5%, the concave portion does not have a sufficient volume, which may hinder long-term operation. On the other hand, if it exceeds 30%, the area that receives the load decreases and the surface pressure becomes excessive, which may cause abnormal wear.

  The recesses can be formed in the form of recesses or grooves that are independently dispersed on the resin layer 2 provided on the sliding part of the inner peripheral wall surface or the sliding part of the end surface. The number is not particularly limited. Of these recesses, the most preferable form is a groove-like shape, and the groove-like recesses are arranged in parallel with the central axis of the bearing inner diameter, or have an angle so-called spiral groove arrangement. Can do. In addition, the length and the number of the recesses may be a length and the number that satisfy the ratio of the apparent area of the recesses. Furthermore, when providing the said several recessed part, it is preferable to arrange | position these at equal intervals seeing from the whole sliding part of an internal peripheral wall surface, or the sliding part of an end surface.

  The concave portion can be formed into a predetermined shape by machining, sandblasting, etching, pressure transfer, or the like. Moreover, you may employ | adopt the method in which a recessed part is formed simultaneously with shaping | molding by setting a convex part shape to the metal mold | die at the time of insert molding previously.

  Furthermore, when a porous sintered metal is used as the metal constituting the bearing body 1 of the high-precision sliding bearing according to the present invention, the sintered metal can be used by impregnating the lubricating oil. When this lubricating oil oozes out to the sliding surface through the resin layer 2, the slidability can be further improved and the life can be extended. At that time, when the resin layer 2 is made of a resin having a porous structure, a resin having excellent affinity with a lubricating oil, a resin blended with a filler having a porous structure, or the like, it becomes more effective.

  The resin having the above porous structure can be produced by the following method. First, two types of resins (resin material A and resin material B) are kneaded and then injection molded to obtain a synthetic resin layer. Then, it processes using the solvent which does not dissolve the resin material B but dissolves the resin material A. Thereby, resin which has a porous structure with a communicating hole can be manufactured.

  Examples of the resin material (resin material B) for forming a resin having a porous structure with the above-described communication holes include polyethylene, polyamide, polyacetal, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyphenylene sulfide, and polyethersulfone. , Polyetherimide, polyepoxy resin, phenol resin and the like. Examples of the resin material that easily dissolves in the solvent (resin material A) include polystyrene that dissolves in a ketone solvent, polyvinyl alcohol that dissolves in water and hot water, and polyvinylpyrrolidone.

  The resin blended with the filler having the above porous structure refers to a resin material blended with a filler having communication holes. Examples of the filler having the communication holes include porous powders such as porous silica. What is preferable as the porous silica is a powder containing amorphous silicon dioxide as a main component. For example, an aqueous solution of alkali silicate containing an alkali metal salt or an alkaline earth metal salt disclosed in Japanese Patent Application Laid-Open No. 2000-143228, which is an aggregate of fine particles having a primary particle diameter of 15 nm or more, Examples include true spherical porous silica that is an aggregate of primary fine particles having a particle size of 3 to 8 nm obtained by emulsification in a solvent and gelation with carbon dioxide.

  In the present invention, porous silica in which primary fine particles having a particle diameter of 3 to 8 nm are aggregated to form true spherical silica particles has communication holes, and thus is particularly preferable. The average particle diameter of the true spherical silica particles is preferably 0.5 to 100 μm, and particularly preferably 1 to 20 μm in consideration of easy handling and imparting sliding properties.

  Examples of such spherical porous silica include Asahi Glass Co., Ltd .; Sunsphere, Suzuki Yushi Kogyo Co., Ltd .; God Ball and the like. Examples of the porous bulk silica include Tokai Chemical Industries, Ltd .; Microid and the like.

True spherical silica particles in which primary fine particles having a particle diameter of 3 to 8 nm are aggregated have a specific surface area of 200 to 900 m ² / g, preferably 300 to 800 m ² / g, a pore volume of 1 to 3.5 ml / g, fine particles. It is preferable that the pore diameter is 5 to 30 nm, preferably 20 to 30 nm, and the oil absorption is 150 to 400 ml / 100 g, preferably 300 to 400 ml / 100 g. Moreover, even if it dries again after being immersed in water, it is preferable that the said pore volume and oil absorption amount maintain 90% or more before immersion. The specific surface area and the pore volume are values measured by a nitrogen adsorption method, and the oil absorption is a value measured according to JIS K5101.

  In addition, it is preferable that the inside and the outer surface of the spherical silica particles are covered with silanol (Si—OH) because the lubricant can be easily held inside.

  Furthermore, the porous silica can be subjected to surface treatment such as organic or inorganic suitable for the base material. The shape of the above-mentioned porous silica is not particularly limited, and non-spherical porous silica can be used as long as the average particle diameter, specific surface area, oil absorption amount and the like are within the range of the above-mentioned spherical silica particles. In addition, spherical and true spherical particles are more preferable from the viewpoint of the attacking property to the sliding partner material and kneading properties. Here, the spherical shape refers to a sphere having a ratio of the short diameter to the long diameter of 0.8 to 1.0, and the true sphere refers to a sphere closer to the true sphere than the above sphere.

  The high-precision sliding bearing according to the present invention is highly accurate, has excellent sliding characteristics, and does not attack a soft mating material such as an aluminum shaft. For this reason, the high-precision sliding bearing can be used in places such as a support bearing that requires rotational accuracy, such as a photosensitive drum, a developing unit, and / or a fixing unit of an office machine such as a copying machine or a printer. By using them, the generation of abnormal noise can be suppressed.

  The high-precision sliding bearing can be used as a carriage bearing. Here, the carriage shaft refers to a shaft that extends in the transport direction of an operation unit such as an ink unit of an ink jet printer and guides the transport of the operation unit, and the carriage bearing refers to when the operation unit moves on the carriage shaft. A bearing provided on the sliding surface. Sintered metal is used for the carriage material of the carriage bearing, that is, the bearing body 1, which is excellent in slidability. May occur. Further, when resin is used as the carriage material, no abnormal noise is generated, but it is difficult to maintain accuracy. On the other hand, when the high-precision sliding bearing according to the present invention is used as a carriage bearing, the high-precision sliding bearing is kept sliding with the resin layer, so that the generation of abnormal noise can be suppressed.

  Furthermore, for the purpose of suppressing the occurrence of abnormal noise, it can be replaced with a rolling bearing used at a relatively low load and low speed.

  When the high-precision sliding bearing according to the present invention is used, it is possible to receive a radial rotational motion or a sliding motion on the inner peripheral wall surface and a sliding motion on the outer surface. In addition, a high-precision sliding bearing having a resin layer on the end face can receive a motion in the thrust direction in addition to them, and can be used in a wider range.

(A) Schematic diagram of the end face of the high-precision sliding bearing according to the present invention in which the bearing body is cylindrical, (b) Cross-sectional view of the high-precision sliding bearing according to the present invention in which the bearing body is cylindrical. (A) Schematic diagram of the end face of a high precision sliding bearing according to the present invention in which the bearing body is a quadrangular prism, (b) Cross section of the high precision sliding bearing according to the present invention in which the bearing body is a quadrangular prism. (A) Schematic diagram of the end face of a high precision slide bearing provided with a resin layer on the end face in addition to the high precision slide bearing of FIG. 1, and (b) A resin layer provided on the end face in addition to the high precision slide bearing of FIG. Cross section of high precision plain bearing (A) Schematic of the end face of an example of a high precision sliding bearing provided with a resin layer on the end face, (b) A cross-sectional view of an example of a high precision sliding bearing provided with a resin layer on the end face Sectional drawing which shows the example of the recessed part of the adhesion surface of a bearing main body and a resin layer (A)-(d) The figure which shows the absolute maximum length of a recessed part

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bearing body 2 Resin layer 2a Resin layer 2b (of sliding part of inner peripheral wall surface) Resin layer 2c (of sliding part of outer surface) Resin layer (of sliding part of end surface)

Claims (9)

The bearing body is made of metal and has a shaft hole penetrating the bearing body. A sliding surface is provided on the inner peripheral wall surface of the shaft hole and an outer surface supporting a load in the radial direction. The sliding surface is a resin material. Covered with a resin layer formed by
Of the surface of the bearing body, the portion covered with the resin layer has a fine recess,
The value of (linear expansion coefficient of resin material (° C. ⁻¹ )) × (thickness of resin layer (μm)) in the resin layer is 0.15 or less,
A high-precision plain bearing in which the total apparent area occupied by the recesses is 20 to 95% of the area of the sliding surface.   The high-precision plain bearing according to claim 1, wherein the external shape is a cylindrical shape, and the outer surface thereof is an outer surface that supports the radial load.   The high-precision plain bearing according to claim 1, wherein the external shape is a quadrangular prism shape, and the outer surface thereof is an outer surface that supports the radial load.   The high-precision sliding bearing according to any one of claims 1 to 3, wherein the sliding surface is provided on an end surface for supporting a load in a thrust direction.   The high precision sliding bearing according to any one of claims 1 to 4, wherein the average size of the recesses is 5 to 300 µm and the average depth is 3 µm or more.   The high-precision sliding bearing according to any one of claims 1 to 5, wherein the metal constituting the bearing body is a sintered metal.   The high precision sliding bearing according to any one of claims 1 to 6, wherein the resin material is blended with a lubricating oil or a solid lubricant.   The high-precision sliding bearing according to any one of claims 1 to 7, which is used in a photosensitive drum, a developing unit, and a fixing unit of a copying machine or a printer.   The high-precision sliding bearing according to any one of claims 1 to 7, which is used as a carriage bearing.

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