JP2010032059A - High precision sliding bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high precision sliding bearing capable of demonstrating an excellent lubricating performance while high preciseness is well maintained. <P>SOLUTION: The sliding bearing is furnished with a metal-made bearing outer circumferential section and a resin layer formed on a sliding section of the bearing outer circumferential section by insert-molding a resin. Fine recesses are provided at least in part of the surface of the bearing outer circumferential section in contact with the resin layer. The resin layer satisfies the relation (linear coefficient of expansion of resin material)×(thickness of resin layer) ≤0.15 and satisfies that the total apparent area occupied by the recesses is 25-95% of the surface area of the bearing outer circumferential section in contact with the resin layer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

  2. Description of the Related Art Conventionally, a slide bearing in which a sintered metal (porous) is impregnated with oil is known as a slide bearing with high rotational accuracy. When this sliding bearing is used by impregnating a sintered metal-based porous material with oil, the oil can be continuously supplied to the sliding interface, so that the frictional force can be reduced. 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 differences 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.

  In addition, as a plain bearing having self-lubricating properties other than those described above, those in which a solid lubricant such as PTFE, graphite, or molybdenum disulfide is blended in a resin, or a lubricant or wax is blended are known.

  However, when a metal-based porous material is impregnated with oil and used as a slide bearing, the mating material may be worn if the mating material is a soft material such as an aluminum material. Further, when the supply of the lubricating oil is interrupted, a metal contact is temporarily generated, so that an abnormal noise is generated, and there is a possibility that the friction proceeds rapidly. Further, when the load is extremely large, the metal contact is likely to occur even when the sliding speed is low and an oil film cannot be formed.

  On the other hand, if the material of the slide bearing is a resin material having good sliding characteristics, even the soft material partner will not attack the partner material. However, in general, resin materials have a larger coefficient of linear expansion and water absorption than metal materials, and when the operating temperature range is wide, when used at low temperatures, the resin sliding material may shrink due to shrinkage or at high temperatures. In use, volume restriction escapes to the inner diameter side due to the shape constraint from the outer diameter side housing, and the inner diameter dimension becomes smaller and the shaft is stiffened. For this reason, in the case of a resin bearing, it is inevitably necessary to make a gap between the bearings large, and there is a problem that rotational accuracy deteriorates. Further, if the resin sliding bearing absorbs water, volume expansion occurs, which causes a problem that the gap with the shaft changes, which is not preferable.

  The present invention has been made to address the above-described problems, and an object of the present invention is to provide a high-accuracy plain bearing excellent in lubricity while having high accuracy.

  This invention uses a metal as the bearing outer peripheral portion, inserts a resin material into the sliding portion of the bearing outer peripheral portion to form a resin layer, and contacts at least the resin layer on the surface of the bearing outer peripheral portion. A fine concave portion is provided on the surface portion of the outer peripheral portion of the bearing, and (the linear expansion coefficient of the resin material) × (the thickness of the resin layer) in the resin layer is 0.15 or less, and the total apparent area occupied by the concave portion is The said subject was solved by setting it as 25 to 95% of the area of the surface part of the bearing outer peripheral part which contacts the said resin layer.

  Since the predetermined resin layer is formed on the sliding portion of the outer peripheral portion of the bearing, the dimensional change due to the temperature change of the resin layer can be suppressed. For this reason, it has excellent lubricity while having high accuracy.

  In addition, since a predetermined fine recess is provided at least on the surface portion of the bearing outer periphery that is in contact with the resin layer, the resin enters the fine recess when the resin layer is formed. Due to the effect, the adhesion between the outer peripheral portion of the bearing and the resin layer can be improved.

  In the high-accuracy plain bearing according to the present invention, since a predetermined resin layer is formed on the sliding portion of the outer peripheral portion of the bearing, a dimensional change due to a temperature change of the resin layer can be suppressed. For this reason, it has excellent lubricity while having high accuracy.

  Further, since the predetermined resin layer is formed on the sliding portion, it is possible to attack the soft mating member and suppress the generation of abnormal noise.

  Moreover, a predetermined | prescribed fine recessed part can be provided in the surface part of the bearing outer peripheral part which contacts the said resin layer at least among the surfaces of a bearing outer peripheral part. Thereby, when forming a resin layer, since resin enters this fine recessed part, the adhesiveness of a bearing outer peripheral part and a resin layer can be improved according to an anchor effect.

(A)-(d) The schematic diagram for demonstrating the magnitude | size of a recessed part (A)-(f) Sectional drawing which shows the example of the position which the resin layer forms in a bearing outer peripheral part

  The high-accuracy plain bearing according to the present invention uses a metal as a bearing outer peripheral portion and inserts a resin material into a sliding portion of the bearing outer peripheral portion to form a resin layer.

  The said bearing outer peripheral part is a cylindrical member which comprises the outer peripheral part of a slide bearing, and is a member which has a sliding part. The sliding portion refers to a sliding portion on the inner diameter side for supporting a load in the radial direction. When supporting a load in the thrust direction, not only the inner sliding portion but also an end surface sliding portion is used. Includes moving parts.

  As the metal constituting the outer peripheral portion of the bearing, it is preferable to use a metal having a fine recess from the viewpoint of bondability with the resin layer, and a sintered metal is more preferable. In particular, when a sintered metal is used, the recesses of the sintered metal communicate with each other to form a communication hole. Therefore, when the resin material is insert-molded, the resin enters the communication hole, A bearing outer peripheral part and a resin layer 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 adhesiveness with the resin layer, 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.

  Of the surface of the bearing outer peripheral portion, a fine recess is provided at least on the surface portion of the bearing outer peripheral portion in contact with the resin layer. When the resin layer is formed, the resin enters the fine recesses, so that the adhesion between the bearing outer peripheral portion and the resin layer 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 surface area of the outer peripheral portion of the bearing in contact with the resin layer. 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. In addition, the said apparent area means the area which a recessed part occupies when the surface part of said bearing outer peripheral part is seen from upper direction.

  The size of the recess is preferably 5 to 300 μm, and preferably 10 to 250 μm. As shown in FIGS. 1A to 1D, the size of the recess represents the absolute maximum length (the maximum length of any two points existing around the recess). When the size is less than 5 μm, the molten resin cannot easily enter the hole, 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 size of the recess can be adjusted by adjusting the particle diameter of the metal particles, the density of the sintered metal, the size of the sizing mold, or the like.

  The depth of the recess is preferably 3 to 500 μm, and preferably 3 to 300 μm. If the thickness is less than 3 μm, the molten resin cannot easily enter the hole, and thus a sufficient anchor effect may not be exhibited. On the other hand, if it is larger than 500 μm, the dimensional accuracy is difficult to obtain, and the mechanical strength may be extremely lowered.

  The concave portion can be formed into a predetermined surface shape by, for example, machining, sand blasting, etching, or transferring unevenness by pressure. 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 is formed by insert-molding a resin material on the sliding portion surface of the bearing outer peripheral portion. The resin material is preferably a material having excellent slidability when formed into a resin layer, and a solid lubricant or lubricating oil can also be blended. Examples of the resin material include polyethylene, polyamide, polyacetal, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyphenylene sulfide, polyethersulfone, polyetherimide, polyamideimide, polyetheretherketone, thermoplastic polyimide, thermosetting polyimide, Examples thereof include an epoxy resin and a phenol resin.

  As the solid lubricant, polytetrafluoroethylene, graphite, molybdenum disulfide, boron nitride, tungsten disulfide and other common solid lubricants, spindle oil, refrigerator oil, turbine oil, machine oil, dynamo oil and other mineral oils, Examples thereof include generally used lubricating oils such as hydrocarbons, esters, polyglycols, silicone oils, synthetic oils such as fluorinated oils, and the like. It is also possible to impregnate the outer periphery of the sintered metal bearing 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.

  An appropriate filler can be added to the resin material in order to improve the friction / wear characteristics and reduce the linear expansion coefficient. Examples include glass fiber, carbon fiber, pitch-based carbon fiber, PAN-based carbon fiber, aramid fiber, alumina fiber, polyester fiber, boron fiber, silicon carbide fiber, boron nitride fiber, silicon nitride fiber, metal fiber, asbestos, quartz Fibers such as wool, knitted fabrics, minerals such as calcium carbonate, talc, silica, clay, mica, inorganic whiskers such as aluminum borate whisker and potassium titanate whisker, carbon black, graphite, polyimide Examples thereof include various heat-resistant resins such as resins and polybenzimidazoles. 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.

  In addition, you may use together the additive which can be widely applied to general synthetic resin with 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. .

  Further, as long as the lubricity of the resin composition of the present invention is not impaired, in the form of the intermediate product or the final product, modification for improving properties can be performed separately by chemical or physical treatment such as annealing treatment. .

In the resin layer, (the linear expansion coefficient of resin material (unit: ° C. ⁻¹ )) × (thickness of resin layer (unit: μm)) is preferably 0.15 or less, preferably 0.13 or less, 0 10 or less is more preferable. When the said value is larger than 0.15, the thickness or expansion | swelling of a resin part also becomes large. At this time, since the outer diameter side of the resin portion is constrained by the metal, it cannot expand beyond the expansion of the metal, expands toward the inner diameter side, and the inner diameter dimension decreases. 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.

  The moldable resin layer has a thickness of about 50 μm, and if it is thinner than this, it becomes difficult to form. Accordingly, the resin expansion coefficient × thickness needs to be 0.003 or more, preferably 0.01 or more, more preferably 0.015 or more.

  The high-accuracy plain bearing according to the present invention includes a bearing outer peripheral portion disposed in a mold, and insert molding of the resin material on the inner diameter surface or end surface serving as a sliding portion and, if necessary, the outer diameter surface. Can be manufactured. Specifically, the outer peripheral part of the bearing is put in the mold in advance, and the molten resin is injected into the gap between the outer peripheral part of the bearing and a mold part such as a core pin using a film gate or a side gate.

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

  Moreover, the place which insert-molds to the bearing outer peripheral part of a resin layer will not be specifically limited if it is a sliding part of a bearing outer peripheral part. For example, there are cases as shown in FIGS. 2A and 2F show the resin layer 2 formed on the inner diameter side sliding portion of the bearing outer peripheral portion 1 in order to support the load in the radial direction. FIG. 2D shows a resin layer 2 formed on the end surface sliding portion of the bearing outer peripheral portion 1 in order to support a load in the thrust direction. FIGS. 2B, 2C, and 2E show the resin layer 2 formed on the inner diameter side sliding portion and the end surface sliding portion of the bearing outer peripheral portion 1 in order to support the load in the radial direction and the thrust direction. is there. Although not shown, a resin layer can be applied to the outer diameter portion of the bearing as necessary. As shown in FIGS. 2C and 2F, the shape of the resin layer having a hooking portion that does not peel off the outer peripheral portion of the bearing and the resin layer may be adopted.

  The high-accuracy plain 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, a recess can be provided in the resin layer 2 provided on the inner diameter side sliding portion of the bearing or the resin layer 2 provided on the end surface sliding portion for thrust load. By providing this recess, wear powder can be captured in this recess and the occurrence of abnormal wear can be suppressed.

  When the recess is provided in the resin layer 2 on the inner diameter side sliding portion, the apparent area per recess is preferably 0.5 to 10% of the total inner diameter surface area, and the total apparent area of the recess is 0.5 to 30% of the total inner surface area is preferred.

  Moreover, when providing the said recessed part in the resin layer 2 of an end surface sliding part, 0.5-10% of the area of the whole one side end surface is preferable as the apparent area per said recessed part provided in the one side end surface, and The total sum of the apparent areas of the recesses provided on one end face is preferably 0.5 to 30% of the entire area of the 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 on the resin layer 2 provided on the inner diameter side sliding portion or the end surface sliding portion independently in the form of dents or grooves, and the shape, size, and number of the recesses are particularly limited. It is not 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 inside diameter side sliding part or the end surface sliding part.

  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 outer peripheral portion of the high-accuracy plain bearing according to the present invention, the sintered metal can be used by impregnating the lubricant. 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 can be manufactured.

  Examples of the resin material (resin material B) for providing the communication holes include polyethylene, polyamide, polyacetal, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyphenylene sulfide, polyethersulfone, polyetherimide, and polyepoxy resin. And phenol resin. 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 thereof include true spherical porous silica which is an aggregate of primary fine particles having a particle diameter 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-accuracy plain 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. Therefore, the high-accuracy plain 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.

  Further, the high-accuracy plain bearing can be used as a carriage bearing. Sintered metal is used for the carriage material of the above-mentioned carriage bearing, and it is excellent in slidability, but it becomes sliding between the mating shaft and metal, so when the lubrication state deteriorates and abnormal noise occurs There is. Also, when resin is used as the carriage, no abnormal noise is generated, but it is difficult to maintain accuracy. On the other hand, when the high-accuracy slide 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.

Example 1
φ8.5 mm × φ14 mm × ^t 5 mm sintered metal (Cu: 90 wt% -Sn: 10 wt% system, average value of pore size: 125 μm, average depth: 20 μm, ratio of recesses: 30%, linear expansion coefficient : 2.0 × 10 ⁻⁵ / ° C.). This bearing outer periphery was mounted in a mold for injection molding, and insert molding was performed by the following method using the resin material shown below on the inner diameter surface to produce a composite slide bearing of φ8 mm × φ14 mm × ^t 5 mm. (Shape: FIG. 2A, resin layer thickness: 250 μm). Using the obtained composite plain bearing, the test was performed under the following conditions. The test results are shown in Table 1.

<Resin material>
Base resin: Polyethylene (Mitsui Petrochemical Co., Ltd .: Rybmer L5000)-68.4 wt%
Filler: Silicone oil (manufactured by Shin-Etsu Silicone Co., Ltd .: KF96H) and porous silica (manufactured by Asahi Glass Co., Ltd .: Sunsphere H33) are prepared. The mixing ratio of porous silica: silicone oil was 1: 2.76 (weight conversion), and the mixture: 31.6 wt% and polyethylene resin: 68.4 wt% were melt-kneaded with a biaxial extruder to prepare pellets.

<Insert molding conditions>
A sintered metal having a predetermined shape was fixed in the mold, and insert molding was performed using oil-containing pellets.
-Mold temperature: 100 ° C
・ Molding temperature: 210 ℃
・ Injection pressure: 140 MPa

<Test conditions>
[Abrasion / friction test]
-Opposite material shaft: A5056 (aluminum alloy, Ra = 0.8 μm), φ7.985 mm
・ Surface pressure: 1 MPa (converted to projected area)
・ Peripheral speed: 3m / min
・ Temperature: 30 ℃ ・ Time: 120h
・ Measurement items are the specific wear amount of the test bearing, the presence or absence of shaft wear, and the dynamic friction coefficient at the end of the test. The clearance between the shaft and the slide bearing was 15 μm (measured at 20 ° C.).

[Measurement of changes in inner diameter]
In order to investigate the influence of expansion due to heat, the outer diameter side of the slide bearing is constrained with sintered metal, and the dimensions can be changed only from the inner diameter side to -10 ° C to 60 ° C. The degree of change was measured (the amount of dimensional change at −10 ° C. and 60 ° C. was determined based on the 20 ° C. dimension). Measure the dimensional change of the inner diameter of the specimen and the dimensional change of the shaft at each temperature. When the gap is 0 to less than 25 μm: ○, When the gap is less than 0 (shaking on the shaft) or 25 μm or more: × It was determined.

[Measurement of gaps]
The gap between the resin layer and the shaft made of A5056 interpolated was measured at −10 ° C. and 60 ° C. The initial gap was set to 15 μm. Moreover, the dimensional change amount of the shaft was −5.2 μm (in the case of −10 ° C.) and 7 μm (in the case of 60 ° C.) (the linear expansion coefficient of the shaft material was 2.2 × 10 ⁻⁵ / ° C.). .

(Example 2)
φ9 mm × φ14 mm × ^t 5 mm sintered metal (Cu: 90 wt% -Sn: 10 wt% system, average pore size: 125 μm, average depth: 30 μm, proportion of recess: 30%, linear expansion coefficient: 2 0.0 × 10 ⁻⁵ / ° C.), except that a bearing outer peripheral portion was used, a composite plain bearing of φ8 mm × φ14 mm × ^t 5 mm was manufactured in the same manner as in Example 1 (shape; FIG. 2A) Resin layer thickness: 500 μm). Using the obtained composite plain bearing, the test was performed under the above conditions. The test results are shown in Table 1.

(Example 3)
φ9.54 mm × φ14 mm × ^t 5 mm sintered metal (Cu: 90 wt% -Sn: 10 wt% system, average value of hole size: 125 μm, average depth: 30 μm, proportion of recess: 30%, linear expansion coefficient : 2.0 × 10 ⁻⁵ / ° C.), except that a bearing outer peripheral portion was used, in the same manner as in Example 1, a φ8 mm × φ14 mm × ^t 5 mm compound slide bearing (shape; FIG. 2 (a), resin Layer thickness: 770 μm). Using the obtained composite plain bearing, the test was performed under the above conditions. The test results are shown in Table 1.

Example 4
φ9.8 mm × φ14 mm × ^t 5 mm sintered metal (Cu: 90 wt% -Sn: 10 wt% system, average value of pore size: 125 μm, average depth: 30 μm, proportion of recess: 30%, linear expansion coefficient : 2.0 × 10 ⁻⁵ / ° C.), except that a bearing outer peripheral portion was used, in the same manner as in Example 1, a φ8 mm × φ14 mm × ^t 5 mm compound slide bearing (shape; FIG. 2 (a), resin (Thickness: 900 μm). Using the obtained composite plain bearing, the test was performed under the above conditions. The test results are shown in Table 1.

(Example 5)
φ10.3 mm × φ14 mm × ^t 5 mm sintered metal (Cu: 90 wt% -Sn: 10 wt% system, average pore size: 125 μm, average depth: 30 μm, recess ratio: 30%, linear expansion coefficient : 2.0 × 10 ⁻⁵ / ° C.), except that a bearing outer peripheral portion was used, in the same manner as in Example 1, a φ8 mm × φ14 mm × ^t 5 mm compound slide bearing (shape; FIG. 2 (a), resin Thickness of 1150 μm). Using the obtained composite plain bearing, the test was performed under the above conditions. The test results are shown in Table 1.

(Example 6)
φ8.5 mm × φ14 mm × ^t 5 mm sintered metal (Cu: 90 wt% -Sn: 10 wt% system, average value of pore size: 250 μm, average depth: 50 μm, ratio of recesses: 90%, linear expansion coefficient : 2.0 × 10 ⁻⁵ / ° C.), except that a bearing outer peripheral portion was used, in the same manner as in Example 1, a φ8 mm × φ14 mm × ^t 5 mm compound slide bearing (shape; FIG. 2 (a), resin (Thickness: 250 μm). Using the obtained composite plain bearing, the test was performed under the above conditions. The test results are shown in Table 1.

(Example 7)
φ8.5 mm × φ14 mm × ^t 5 mm sintered metal (Cu: 90 wt% -Sn: 10 wt% system, average pore size: 10 μm, average depth: 5 μm, recess ratio: 80%, linear expansion coefficient : 2.0 × 10 ⁻⁵ / ° C.), except that a bearing outer peripheral portion was used, in the same manner as in Example 1, a φ8 mm × φ14 mm × ^t 5 mm compound slide bearing (shape; FIG. 2 (a), resin (Thickness: 250 μm). Using the obtained composite plain bearing, the test was performed under the above conditions. The test results are shown in Table 1.

(Example 8)
φ8.5 mm × φ14 mm × ^t 5 mm sintered metal (Cu: 90 wt% -Sn: 10 Wt% system, average pore size: 125 μm, average depth: 50 μm, ratio of recess: 30%, linear expansion coefficient : 2.0 × 10 ⁻⁵ / ° C.) φ8 mm × φ14 mm in the same manner as in Example 1, except that the following resin materials were used and the following insert molding conditions were used. X ^t 5 mm compound plain bearing (shape; FIG. 2A, resin thickness: 250 μm) was manufactured. Using the obtained composite plain bearing, the test was performed under the above conditions. The test results are shown in Table 1.

<Resin material>
-Base resin: polyphenylene sulfide (manufactured by Toprene: T4AG)-43.6 wt%
Filler: Polytetrafluoroethylene (manufactured by Sumitomo 3M: Hostaflon TF9205) -25.4 wt% aramid fiber (manufactured by Akzo Nobel: Twaron Microl 088) -8.5 wt% lithium phosphate Yoneyama Chemical: lithium phosphate) -22. Prepare 5 wt%. These materials were melt-kneaded using a biaxial extruder to produce pellets.

<Insert molding conditions>
A sintered metal having a predetermined shape was fixed in the mold, and insert molding was performed using pellets.
Mold temperature: 150 ° C
Molding temperature: 305 ° C
Injection pressure: 200 MPa

Example 9
φ 9 mm × φ 14 mm × ^t 5 mm sintered metal (Cu: 90 wt% -Sn: 10 wt% system, average pore size: 250 μm, average depth: 50 μm, ratio of recesses: 90%, expansion coefficient: 2. 0 × 10 ⁻⁵ / ° C.), except that the outer peripheral portion of the bearing was used in the same manner as in Example 8, φ8 mm × φ14 mm × ^t 5 mm compound slide bearing (shape; FIG. 2 (a), resin thickness : 500 μm). Using the obtained composite plain bearing, the test was performed under the above conditions. The test results are shown in Table 1.

(Example 10)
Silicone oil (manufactured by Shin-Etsu Silicone Co., Ltd .: KF96H) was impregnated in the metal portion of the outer peripheral portion of the composite slide bearing manufactured in Example 1. Using this, the test was conducted under the above conditions. The test results are shown in Table 1.

(Example 11)
In the resin layer on the inner diameter surface of the composite plain bearing manufactured in Example 1, a groove-shaped recess (width × length × depth = 1 mm × 5 mm × 150 μm, cross-sectional shape: semicircular, arrangement location: axial direction 3). At this time, the ratio of the apparent area per one recessed portion to the total inner diameter area is {(1 mm × 5 mm) / (8 mm × 5 mm × π)} × 100 = 3.97 (%). Using this, the test was conducted under the above conditions. The test results are shown in Table 1.

Example 12
Silicone oil (manufactured by Shin-Etsu Silicone Co., Ltd .: KF96H) was impregnated in the metal portion of the outer peripheral portion of the composite slide bearing having a groove-like recess in the resin layer on the inner diameter surface of the bearing manufactured in Example 11. Using this, the test was conducted under the above conditions. The test results are shown in Table 1.

(Comparative Example 1)
φ8 mm × φ14 mm × ^t 5 mm sintered metal (Cu: 90 wt% -Sn: 10 wt% system, average value of pore size: 250 μm, average depth: 50 μm, ratio of recess: 30%, expansion coefficient: 2. A bearing outer peripheral portion made of 0 × 10 ⁻⁵ / ° C., Cu—Sn system) is used as a sliding bearing. This sintered metal bearing was immersed in ester oil (manufactured by Nippon Oil & Fats: H481R), vacuum impregnation treatment was performed, and oil was sealed in the pores. Various tests were performed under the same conditions as in Example 1 using this test bearing. The test results are shown in Table 1.

(Comparative Example 2)
A plain bearing of φ8 mm × φ14 mm × ^t 5 mm was manufactured using only the resin material used in Example 1, and a friction / wear test and various evaluation tests were performed under the same conditions as in Example 1. The test results are shown in Table 1.

(Comparative Example 3)
φ11.2 mm × φ14 mm × ^t 5 mm sintered metal (Cu: 90 wt% -Sn: 10 wt% system, average value of pore size: 250 μm, average depth: 50 μm, proportion of recess: 30%, expansion coefficient: 2.0 × 10 ⁻⁵ / ° C.) is prepared. The outer periphery of the bearing is mounted in a mold for injection molding, insert molding of the resin material of Example 1 is performed on the inner diameter surface, and a composite plain bearing of φ8 mm × φ14 mm × ^t 5 mm (shape; FIG. 2 (a), Resin thickness: 1600 μm) was manufactured. Various tests were performed under the same conditions as in Example 1. The test results are shown in Table 1.

(Comparative Example 4)
except for using the bearing outer peripheral portion made of SUS304 (surface roughness Ra = 0.01 [mu] m) of φ9mm × φ14mm × ^t 5mm, the same procedure as in Example 2 was fabricated composite sliding bearing of φ8mm × φ14mm × ^t 5mm. The resulting composite plain bearing could not be tested because peeling occurred between the sintered metal layer and the resin layer.

(Comparative Example 5)
φ8.5 mm × φ14 mm × ^t 5 mm sintered metal (Cu: 90 wt% -Sn: 10 Wt% system, average value of pore size: 250 μm, average depth: 100 μm, ratio of recesses: 10%, expansion coefficient: A composite slide bearing of φ8 mm × φ14 mm × ^t 5 mm (resin wall thickness: 250 μm) was produced in the same manner as in Example 1 except that the outer peripheral part of the bearing consisting of 2.0 × 10 ⁻⁵ / ° C.) was used. . The resulting composite plain bearing could not be tested because peeling occurred between the sintered metal layer and the resin layer.

(Comparative Example 6)
φ8.5 mm × φ14 mm × ^t 5 mm sintered metal (Cu: 90 wt% -Sn: 10 wt% system, average value of hole size: 3 μm, average depth: 1 μm, ratio of recess: 30%, expansion coefficient: 2.0 × 10 ⁻⁵ / ° C.) A composite plain bearing (resin wall thickness: 250 μm) of φ8 mm × φ14 mm × ^t 5 mm was manufactured in the same manner as in Example 1 except that the outer peripheral portion of the bearing was used. . The resulting composite plain bearing could not be tested because peeling occurred between the sintered metal layer and the resin layer.

(result)
As shown in Examples 1 to 11, when a sintered metal having an appropriate hole size, depth, and ratio of recesses and a resin layer are used in combination, the adhesion between the sintered metal and the resin layer is insufficient. No peeling occurred. The specific wear amount was as small as 100 × 10 ⁻⁸ mm ³ / (N · m) or less, the wear of the counterpart material shaft was not found, and the dynamic friction coefficient was as low as 0.2 or less. Further, the dimensional change due to thermal expansion was small, and the dimensional stability was excellent.

  On the other hand, when the plain bearing was constituted only by the sintered metal layer of Comparative Example 1, the dimensional change was small, but the shaft was worn and the friction coefficient was as high as 0.5. In addition, when the plain bearing is configured only with the resin material of Comparative Example 2, the specific wear amount is small, the shaft is not worn, the friction coefficient is small, but the dimensional change due to thermal expansion is large, so high accuracy is required. It is not suitable for use in certain places. In the case of the bearing using the resin layer and the sintered metal layer of Comparative Example 3 in combination, the specific wear amount is small, the shaft is not worn and the friction coefficient is small, but since the resin layer is thick, the shape from the metal layer at high temperatures Under restraint, the volume expansion escapes to the inner diameter side, and the inner diameter dimension becomes smaller. As a result, the gap with the shaft becomes significantly smaller than the initial value, and the shaft is not preferable because it is uneven. When the SUS304 of Comparative Example 4 and the resin layer were used in combination, the surface of the SUS304 was smooth and the adhesion with the resin layer was weak, so peeling occurred at the interface due to molding shrinkage. When there is no unevenness on the surface of the metal layer, it is difficult to obtain a composite of metal and resin. In the case of the sintered metal having a small concave portion ratio of 3% in Comparative Example 5, the adhesion force to the resin layer was weak as in the case of using SUS304 of Comparative Example 4, and peeling occurred at the interface due to molding shrinkage. When the size of the hole of Comparative Example 6 was as small as 3 μm, the molten resin could not enter the hole, so that the adhesion was reduced and peeling occurred at the interface due to molding shrinkage.

Claims (12)

Metal is used as the bearing outer periphery, and a resin layer is formed by insert molding a resin material on the sliding portion of the bearing outer periphery .
Of the surface of the bearing outer periphery of this, at least the resin layer recesses for fine anchoring effect on the surface portion of the bearing outer peripheral portion contacting provided with Rutotomoni, among the resin layers, the inner diameter side sliding portion of the bearing The resin layer provided and the resin layer provided on the end load sliding portion for thrust load are provided with a recess for capturing wear powder,
(Linear expansion coefficient of resin material) × (wall thickness of resin layer) in the resin layer is 0.15 or less,
The size of the anchor effect recess is 5 to 300 μm and the depth is 3 μm or more, and the total apparent area occupied by the anchor effect recess is the area of the surface portion of the bearing outer peripheral portion in contact with the resin layer. and 25 to 95% of,
When the resin layer is provided on the inner diameter side sliding portion of the bearing, the apparent area of the concave portion for capturing the wear powder is 0.5 to 30% of the total inner diameter surface area, and the resin layer Is provided in the thrust load end face sliding portion, a high-accuracy plain bearing that is 0.5 to 30% of the entire area of one end face .   2. The high-accuracy plain bearing according to claim 1, wherein the sliding portion of the outer peripheral portion of the bearing is an inner diameter side sliding portion for supporting a radial load.   The sliding bearing according to claim 1, wherein the sliding portion of the outer peripheral portion of the bearing is an inner diameter side sliding portion and an end surface sliding portion for supporting loads in both the radial direction and the thrust direction.   The high-accuracy plain bearing according to any one of claims 1 to 3, wherein the metal constituting the outer peripheral portion of the bearing is a sintered metal.   The high-precision slide bearing according to claim 4, wherein the sintered metal is a porous sintered metal and is impregnated with a lubricating oil.   The high-precision slide bearing according to any one of claims 1 to 5, wherein the resin material is a resin material having a porous structure. The high-precision slide 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 slide bearing according to claim 6 , wherein the resin material is blended with a lubricating oil and a filler having a porous structure. The high-precision sliding bearing according to claim 8 , wherein the filler having a porous structure is porous silica.   The high-accuracy plain bearing according to claim 9, wherein the filler having a porous structure is a mixture of a lubricating oil made of silicone oil mixed with porous silica and absorbed. The high-precision slide bearing according to any one of claims 1 to 10 , which is used in a photosensitive drum, a developing unit, and / or a fixing unit of a copying machine or a printer. The high-precision slide bearing according to any one of claims 1 to 10 , which is used as a carriage bearing.

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