JP2013024252A - Rolling bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing device preventing damage of a fit surface for a long period even when creep occurs during loose-fitting and partially replaceable with a simple structure.SOLUTION: The rolling bearing device 1 is formed of a rolling bearing part 2 having an inner ring 3, an outer ring 4 and conical rollers 5 interposed as a plurality of rolling elements between the inner ring 3 and the outer ring 4, and an annular slide bearing part 7 arranged on the inner diameter side of the inner ring 3, and supports a mating shaft 10 through loose fit by an inner diameter part of the slide bearing part 7. The slide bearing part 7 is pressed in and fixed to the inner diameter side of the inner ring 3 of the rolling bearing part 2, and at least the inner diameter part of the slide bearing part 7 is a resin layer 9 formed of a resin composition.

Description

  The present invention relates to a rolling bearing device, and more particularly to a rolling bearing device that is used in construction machines and the like and uses an inner ring and a counterpart shaft by a clearance fit.

  When using a rolling bearing, the inner ring may be used as a clearance fit in the case of inner ring rotation / rotational load or inner ring stationary / static load. The clearance fitting of the inner ring means that the outer diameter of the counterpart shaft is set smaller than the inner diameter of the inner ring that supports it. In a rolling bearing used for supporting a wheel of a construction machine vehicle or a rolling bearing that supports a gear such as a transmission, the inner ring may be used as a clearance fit in consideration of assemblability.

  If a swinging load is applied to the inner ring while the inner ring and the mating shaft are in a clearance fit, the inner ring is slightly behind the shaft rotation and opposite to the rotation direction due to the difference in the inner ring inner circumference and shaft outer diameter circumference. The phenomenon of rotating in the direction (creep) occurs. Even if the whirling load does not act, when the rolling element passes on the inner ring raceway surface, the circumferential stress distribution generated on the inner ring inner diameter surface by contact with the rolling element moves, so the inner ring inner diameter surface Repeats expansion and contraction locally. For this reason, the inner ring slips between the shaft in the same direction as the rotation of the bearing. These slips may cause damage such as wear on the inner ring inner surface and the mating shaft. In order to prevent the damage due to the slip, conventionally, (1) the slip itself is prevented, or (2) no wear is generated even if the slip occurs.

  As the means (1), there is a means for preventing slipping by embedding a female screw or a key and fixing an inner ring or an outer ring. For example, in a rolling bearing configured to sandwich a plurality of rolling elements supported at a predetermined interval in the circumferential direction by a cage between an inner ring fitted on the shaft and an outer ring fitted on the housing, It has been proposed that the pressure contact surface between the inner ring and the shaft has a concave cross section and opens to the outside of the bearing, and a key groove having a predetermined shape is formed to prevent the inner ring from rotating with the inserted key (Patent Document). 1).

  As another means of the above (1), in a double row rolling bearing, an annular band mounting groove is provided on the outer diameter surface of the outer ring, and a band made of a material having a larger linear expansion coefficient than the outer ring is provided in the band mounting groove. A worn one has been proposed (see Patent Document 2). In this configuration, even if loose fitting occurs due to the difference in linear expansion coefficient between the housing made of aluminum and the bearing outer ring as the temperature rises, the band made of a material with a large linear expansion coefficient will thermally expand. And the loosening of the fitting between the inner ring and the rotating shaft is prevented.

  As means of (2) above, manganese phosphate, zinc phosphate, phosphoric acid are formed on the mating surfaces of the ceramic inner and outer rings and the steel shaft or housing in order to prevent damage when gaps occur. A bearing mounting structure in which a coating such as ester is formed has been proposed (see Patent Document 3). In addition, in a sliding member that makes rolling contact or sliding contact, a member that forms a DLC film provided with an intermediate layer on the sliding surface to prevent progress of wear due to foreign matter has been proposed (see Patent Document 4).

JP 2006-194418 A JP-A-9-269909 Japanese Utility Model Publication No. 5-81529 JP 2007-327037 A

  However, the means using the female screw is fastening by friction between the screw tip and the counterpart of the shaft, and slipping cannot be prevented when the driving torque of the inner ring with respect to the counterpart shaft is large. Further, as in Patent Document 1, in the means for fixing with a key, it is necessary to provide a key groove on the inner ring and the counterpart shaft, and there is a concern that the strength may be reduced or damage may be caused by stress concentration on the key groove. Also, as in Patent Document 2, the effect of the means using the band is not stable because dimensional management is difficult. In particular, construction machinery vehicles such as bulldozers and large trucks have excessive outer dimensions and weight, and excessive driving torque and load on rolling bearings used for wheel support, etc., and the above means stably prevent slipping. Difficult to do.

  In addition, as in Patent Document 3 and Patent Document 4, when a manganese phosphate film or a DLC film is formed, the film is peeled off under severe conditions such as high torque and high surface pressure as in the above construction machine application. Damage to the inner ring inner surface and the mating shaft may not be sufficiently prevented due to wear or wear. Furthermore, construction machinery vehicles frequently travel on rough roads such as rough terrain and rock soil, and foreign materials such as sand are unavoidable, and it is difficult to prevent damage to the inner ring inner diameter surface and the mating shaft only with the above coating treatment. is there. If the coating peels off, creep will cause seizure with abnormal heat generation on the mating surface between the inner ring and the mating shaft, breakage of the inner ring or the mating shaft due to abnormal wear, or wear powder from the bearing. There is a risk of bearing damage due to penetration of wear powder.

  In order to avoid the above problems during use, it is necessary to replace the rolling bearings periodically. However, since the female screws, key grooves, and coatings are directly provided on the race, It is not possible to replace the entire rolling bearing. Rolling bearings for construction machinery use have a large outer diameter, and therefore the cost of rolling bearings is high, and the development of an extended replacement period and a more efficient replacement method is desired.

  The present invention has been made to cope with such problems. Even when creep occurs during clearance fitting, damage to the fitting surface can be prevented over a long period of time, and partial replacement can be performed with a simple structure. It is an object of the present invention to provide a rolling bearing device capable of performing the above.

  The rolling bearing device according to the present invention includes a rolling bearing portion having an inner ring and an outer ring, and a plurality of rolling elements interposed between the inner ring and the outer ring, and an annular sliding bearing portion disposed on the inner diameter side of the inner ring. A rolling bearing device that supports a mating shaft with a clearance fit at an inner diameter portion of the sliding bearing portion, wherein the sliding bearing portion is press-fitted and fixed to an inner diameter side of an inner ring of the rolling bearing portion. At least an inner diameter part of the part is a resin layer formed from a resin composition.

  An outer diameter portion of the sliding bearing portion is formed of a metal base material, and the resin layer is formed as an inner diameter portion on one surface of the metal base material. The resin layer is formed by forming a porous layer made of sintered metal on one surface of the metal base material and impregnating and coating the resin composition on the porous layer. And The surface of the metal base material on which the porous layer is formed is plated equivalent to the sintered metal.

  The sliding bearing portion has a flange that covers an end surface of the inner ring of the rolling bearing portion on one side in the width direction, and the resin layer is formed on the opposite surface of the flange to the inner ring side. .

  The sliding bearing part is detachable from an inner ring of the rolling bearing part.

  The rolling bearing device supports a counterpart shaft used in a construction machine.

  The resin composition has a polytetrafluoroethylene (hereinafter referred to as PTFE) resin as a main component. The resin composition includes at least one synthetic resin selected from a polyimide (hereinafter referred to as PI) resin and a polyphenylene sulfide (hereinafter referred to as PPS) resin, a granular inorganic filler, and a carbon fiber. Features. In particular, the blending ratio of each component in the resin composition is such that the synthetic resin is 5 to 30% by volume, the granular inorganic filler is 3 to 30% by volume, the carbon fiber is 1 to 15% by volume, and the balance is the PTFE. It is a resin.

  The rolling bearing device according to the present invention includes a rolling bearing portion having an inner ring and an outer ring, and a plurality of rolling elements interposed between the inner ring and the outer ring, and an annular sliding bearing portion disposed on the inner diameter side of the inner ring. And the other shaft is supported by a clearance fit at the inner diameter portion of the sliding bearing portion, and the sliding bearing portion is press-fitted and fixed to the inner diameter side of the inner ring of the rolling bearing portion. Since the inner diameter portion is a resin layer formed from a resin composition, even when creep occurs in the inner ring, the resin layer of the sliding bearing portion and the outer diameter surface of the metal counterpart shaft come into contact with each other, so that the metal contact Can be prevented, and damage such as wear of the mating shaft can be prevented. In addition, since the sliding portion with the mating shaft is a press-fitted and sliding bearing portion, there is no risk of peeling like a coating even under high surface pressure, and damage such as wear of the mating shaft can be prevented over a long period of time. .

  Since the outer diameter portion of the slide bearing portion is formed of a metal base material, and the resin layer is formed as an inner diameter portion on one surface of the metal base material, the slide bearing portion is excellent in mechanical strength and rolls the slide bearing portion. It is possible to prevent damage when press-fitting into the bearing.

  Further, since the resin layer is formed by impregnating and coating a porous layer made of a sintered metal formed on one surface of the metal base material with the resin composition, it has excellent sliding characteristics under high surface pressure. Furthermore, the adhesiveness of a porous layer and a metal base material can be improved by plating equivalent to the said sintered metal on the surface which forms the porous layer of the said metal base material.

  The sliding bearing portion has a flange that covers the end surface of the inner ring of the rolling bearing portion on one side in the width direction, and a resin layer is formed on the opposite surface of the flange on the inner ring side. It is possible to prevent damage such as wear on the shoulder and the end face (axial contact surface). Moreover, by having a flange, it is excellent in workability of press-fitting and removing the sliding bearing portion.

  Since the above-mentioned sliding bearing part is removable from the inner ring of the rolling bearing part, when the sliding bearing part which is the sliding part is damaged, the rolling bearing part remains as it is and only the sliding bearing part is replaced. Can do. Therefore, the maintenance cost can be greatly reduced compared with the case where the entire rolling bearing device is replaced.

  Since the resin composition contains a PTFE resin as a main component, and contains at least one synthetic resin selected from a PI resin and a PPS resin, a granular inorganic filler, and carbon fiber, if necessary, the surface pressure is low. Excellent sliding properties such as wear resistance and creep resistance.

  The rolling bearing device of the present invention can prevent damage such as wear of the counterpart shaft over a long period of time even when creep occurs in the inner ring under high surface pressure, and can be partially replaced. It is suitable as a rolling bearing device that supports a mating shaft used in a machine.

It is an axial sectional view showing an example of the rolling bearing device of the present invention. In the rolling bearing device of FIG. 1, it is a figure which shows the state which decomposed | disassembled the rolling bearing part and the sliding bearing part. It is axial direction sectional drawing which shows the other example of the rolling bearing apparatus of this invention. FIG. 4 is a diagram illustrating a state in which a rolling bearing portion and a sliding bearing portion are disassembled in the rolling bearing device of FIG. 3.

  The rolling bearing device of the present invention is applied to a use in a case where the mating shaft is a clearance fit. For example, there are construction machine applications such as rolling bearings used for supporting wheels of construction machine vehicles such as dump trucks, hall loaders, cranes, and bearings for supporting gears such as transmissions. In these construction machinery applications, bearings having an inner diameter of about 50 to 600 mm are usually used, and are often used under conditions such as oil bath lubrication at a relatively high load and low speed rotation.

  An embodiment of the rolling bearing device of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view in the axial direction of a rolling bearing device of the present invention, and FIG. 2 is a diagram showing a state in which a rolling bearing portion and a sliding bearing portion are disassembled. As shown in FIG. 1, the rolling bearing device 1 includes a rolling bearing portion 2 and a sliding bearing portion 7. The rolling bearing portion 2 includes an inner ring 3 and an outer ring 4, and tapered rollers 5 that are a plurality of rolling elements interposed between the inner ring 3 and the outer ring 4. The plurality of tapered rollers 5 are held at regular intervals by a cage 6 and are lubricated with grease or the like inside the rolling bearing portion. The sliding bearing portion 7 is composed of a metal base 8 that is an outer diameter portion and a resin layer 9 that is an inner diameter portion. The rolling bearing device 1 supports the mating shaft 10 by a clearance fit with a resin layer 9 which is an inner diameter portion of the sliding bearing portion 7. That is, the outer diameter of the mating shaft 10 is set to be smaller than the inner diameter (of the resin layer 9) of the sliding bearing portion 7. As shown in FIG. 2, the sliding bearing portion 7 is an annular member disposed on the inner diameter side of the inner ring 3 of the rolling bearing portion 2, and is press-fitted and fixed to the inner diameter side of the inner ring 3.

  In the example shown in FIG. 1, the plain bearing portion 7 has a multilayer structure including a metal base 8 that is an outer diameter portion and a resin layer 9 that is formed as an inner diameter portion on one surface of the metal base 8. . As the metal substrate 8, steel (such as rolled structural steel such as SPCC) or a metal other than steel, for example, a copper alloy such as stainless steel or bronze can be used. With such a structure, the sliding bearing portion 7 is excellent in mechanical strength and can be prevented from being damaged when the sliding bearing portion 7 is press-fitted into the rolling bearing portion 2.

  The resin layer 9 is molded from a resin composition. As the resin as the main component of the resin composition, a known material used as a sliding bearing material can be used. For example, injection molding of PTFE resin, polyacetal resin, nylon resin, polytetrafluoroethylene / perfluoroalkyl vinyl ether copolymer resin, tetrafluoroethylene / hexafluoropropylene copolymer resin, ethylene-tetrafluoroethylene copolymer resin, etc. Fluorine resin, PI resin that can be injection molded, PPS resin, wholly aromatic polyester resin, polyether ether ketone resin, polyamideimide resin, and the like. Each of these resins may be used alone or a polymer alloy in which two or more kinds are mixed. Moreover, you may mix | blend additives, such as a well-known solid lubricant and a reinforcing material, with this resin composition. The molding method can be appropriately selected according to the material and the aspect of the sliding bearing portion, such as compression molding, extrusion molding, injection molding, and an impregnation coating method described later.

  The resin layer 9 was formed by forming a porous layer made of sintered metal on one surface of the metal substrate 8 and impregnating and coating the porous layer with a resin composition mainly composed of PTFE resin or the like. Preferably. In this case, the sliding bearing portion 7 has a three-layer structure including the metal substrate 8, the porous layer, and the resin-impregnated coating layer, and is excellent in sliding characteristics under high surface pressure.

  The sliding bearing portion 7 may be a resin layer 9 having at least an inner diameter portion formed from the resin composition. Therefore, in addition to the multilayer structure shown in FIG. 1 and the like, a single-layer structure including only the resin layer 9 may be used. Under high torque and high surface pressure conditions as in construction machinery applications, it is difficult to prevent the inner ring creep itself, but at least the inner diameter portion that is the sliding portion with the mating shaft 10 is the resin layer 9. Thus, even when the creep occurs, metal contact can be prevented, and galling and wear can be prevented.

  The thickness of the resin layer 9 in the sliding bearing portion 7 is preferably 0.1 to 0.5 mm, although it depends on the outer diameter of the rolling bearing device itself. Moreover, when forming the sliding bearing part 7 only with the resin layer 9 (single layer), it is preferable to set it as 1-5 mm. By setting it within this range, damage during press fitting can be prevented, and damage such as wear of the counterpart shaft can be prevented over a long period even under severe conditions such as high surface pressure in construction machine applications.

  Another embodiment of the rolling bearing device of the present invention will be described with reference to FIGS. FIG. 3 is a sectional view in the axial direction of the rolling bearing device (with a flange) of the present invention, and FIG. 4 is a view showing a state in which the rolling bearing portion with the flange and the sliding bearing portion are disassembled. As shown in FIGS. 3 and 4, in the rolling bearing device 1 of this aspect, the sliding bearing portion 7 has a flange 8 a that covers the end surface 3 a of the inner ring 3 of the rolling bearing portion 2 on one side in the width direction. A resin layer 9 is also formed on the opposite surface of the flange 8a on the inner ring 3 side. In addition, in the rolling bearing device 1 of this aspect, the configuration of the rolling bearing portion 2 is the same as that shown in FIG.

  The flange 8a is formed by, for example, bending one side in the width direction of the annular steel plate that is the metal base 8 by press working or the like. Further, when the sliding bearing portion 7 is formed only by the resin layer 9 (single layer), it can be integrally formed by injection molding or the like in an annular shape with the flange. By covering the end face 3a of the inner ring 3 of the rolling bearing portion 2 with the flange 8a of the sliding bearing portion 7, damage such as wear on the axial contact surface of the rolling bearing device 1 can be prevented. In addition, by providing the flange 8 a on the sliding bearing portion 7, the workability of press-fitting and removing the sliding bearing portion 7 with respect to the rolling bearing portion 2 is excellent.

  In the rolling bearing device 1, since the sliding bearing portion 7 is press-fitted and fixed to the inner ring 3 of the rolling bearing portion 2, it can be removed. As described above, it is difficult to prevent the occurrence of creep in the clearance-fitting inner ring under high torque and high surface pressure conditions as in construction machinery applications. In the rolling bearing device according to the present invention, even when the creep occurs, damage to the mating shaft and the sliding bearing portion can be prevented for a long period of time compared to those that form a conventional coating film, but replacement is also necessary. Even in this case, since the rolling bearing portion can be left as it is and only the sliding bearing portion can be removed and replaced, the maintenance cost can be greatly reduced compared with the case where the entire rolling bearing device is replaced.

  Moreover, in the inner ring 3 of the rolling bearing part 2, the thickness of the sliding bearing part 7 can be made thinner than the conventionally used inner ring without changing the diameter of the counterpart shaft. It becomes.

  A porous layer made of sintered metal is formed on one surface of a metal base material as a resin layer of a sliding bearing portion, which is a preferred embodiment of the rolling bearing device of the present invention, and PTFE resin is a main component in the porous layer. The case where the resin composition is formed by impregnating and coating will be described in detail below.

  As the sintered metal forming the porous layer, a copper alloy such as copper or bronze is preferable because of excellent frictional wear characteristics. Moreover, in this aspect, it is preferable to apply plating equivalent to the porous layer to the surface of the metal substrate in order to enhance adhesion with the porous layer.

It said main component consisting PTFE resin in the resin _{composition, - (CF 2 -CF 2)} n- in can be used ordinary PTFE resin represented. In addition, perfluoroalkyl ether groups (—C _p F _2p —O—) (p is an integer of 1-4) or polyfluoroalkyl groups (H (CF ₂ ) _q —) (q is 1- Modified PTFE resin introduced with an integer of 20) or the like can also be used. These PTFE resins and modified PTFE resins may employ either a suspension polymerization method for obtaining a general molding powder or an emulsion polymerization method for obtaining a fine powder, but the number average molecular weight (Mn) is from about 500,000. 10 million is preferred.

  The resin composition preferably contains at least one synthetic resin selected from a PI resin and a PPS resin, a granular inorganic filler, and carbon fibers in order to improve sliding characteristics under a high surface pressure. . By containing these, even if it does not mix | blend lead or a lead compound, it is excellent in the sliding characteristic under high surface pressure.

  PI resin and PPS resin are a kind of so-called super engineering plastics, and by blending PI resin or PPS resin with PTFE resin, it is possible to improve the wear resistance and creep resistance characteristics, which were the disadvantages of PTFE resin.

  The particulate inorganic filler is preferably a non-metallic inorganic filler having a spherical, plate-like, or irregular shape with an aspect ratio of 3 or less and capable of being dispersed and blended with the PTFE resin. Examples thereof include calcium sulfate powder, aluminum hydroxide powder, zinc oxide powder, and barium sulfate powder. Moreover, as an average particle diameter (measured value by a laser analysis method), about 1-50 micrometers is preferable.

  As the carbon fiber, either pitch-based or PAN-based can be used. The fiber length of the carbon fiber is preferably a short fiber of 10 to 1000 μm, and more preferably an average fiber length of 50 to 300 μm. The fiber diameter is φ20 μm or less, preferably φ7 to φ15 μm, and the aspect ratio is 5 to 80, preferably 20 to 50. A carbon fiber having this characteristic is excellent in the reinforcing effect, and excellent in wear resistance and creep resistance. The yarn type is not particularly limited, but a 1000 ° C. fired product (carbonized product) is preferable to a 2000 ° C. fired product or a treated product (graphitized product) at a temperature higher than that.

  The blending ratio of each component in the resin composition is 5 to 30% by volume of the synthetic resin, 3 to 30% by volume of the granular inorganic filler, 1 to 15% by volume of the carbon fiber, and the balance is the PTFE. It is preferable to use a resin. If the PI resin or PPS resin exceeds 30% by volume, the coefficient of friction increases under high surface pressure, which may cause problems such as an increase in the amount of heat generated by friction, and if it is less than 5% by volume, the improvement effect cannot be exhibited. If the amount of the particulate inorganic filler exceeds 30% by volume, the mating shaft may be damaged by wear, and if it is less than 3% by volume, the wear resistance effect is not exhibited. If the carbon fiber exceeds 15% by volume, there may be a problem in moldability, and if it is less than 1% by volume, the reinforcing effect is poor.

  Dissolve or disperse each of the above raw materials in a solvent to obtain a dispersion liquid, etc., and after stirring the dispersion liquid to make a paste, impregnate the porous layer on the metal substrate to remove the solvent By doing so, the resin layer of the sliding bearing part is obtained.

  The slide bearing portion of the rolling bearing device of the present invention was specifically evaluated as follows. The test piece of the sliding bearing part was produced by the following method. After degreasing the stainless steel (SUS304) steel plate, copper plating was performed, and bronze powder (those that passed # 100 mesh and turned on with # 200 mesh) was sprayed on the surface of this steel plate. A porous layer having a uniform layer thickness was formed by heating and pressing a steel plate on which bronze powder was uniformly dispersed. On this porous layer, a dispersion liquid of the resin composition adjusted to the blending ratio shown in Table 1 is applied, the solvent is evaporated in a drying furnace, and the porous layer is impregnated and coated with heat and pressure. did.

  The plate material thus obtained was processed into a predetermined test piece shape, and the dynamic friction coefficient and the wear amount were measured with a ring-on-disk type tester. The ring-on-disk type tester is a test apparatus that measures a dynamic friction coefficient and a wear amount by rotating a test piece with a predetermined condition against a fixed member to which a pressing force is applied and fixed. Test conditions were a test for 30 hours at a speed of 153 m / min and a surface pressure of 1.5 MPa, and a dynamic friction coefficient and a wear amount immediately before the end of the test were measured. The measurement results are shown in Table 1.

  As shown in Table 1, as a resin composition for forming the sliding bearing portion, PTFE resin as a main component, at least one synthetic resin selected from PI resin and PPS resin, a granular inorganic filler, and carbon fiber are included. It is understood that the inclusions are preferable because they have wear resistance while maintaining low friction characteristics.

  The rolling bearing device of the present invention can prevent damage such as wear of the counterpart shaft over a long period of time even when creep occurs in the inner ring under high surface pressure, and can be partially replaced. It can be suitably used as a rolling bearing device that supports a mating shaft used in a machine.

DESCRIPTION OF SYMBOLS 1 Rolling bearing apparatus 2 Rolling bearing part 3 Inner ring 4 Outer ring 5 Tapered roller 6 Cage 7 Sliding bearing part 8 Metal base material 9 Resin layer 10 Opposite shaft

Claims (10)

An inner ring and an outer ring, and a rolling bearing part having a plurality of rolling elements interposed between the inner ring and the outer ring, and an annular slide bearing part arranged on the inner diameter side of the inner ring, the inner diameter of the sliding bearing part A rolling bearing device that supports the mating shaft with a clearance fit at the part,
The rolling bearing device is characterized in that the sliding bearing portion is press-fitted and fixed to an inner diameter side of an inner ring of the rolling bearing portion, and at least an inner diameter portion of the sliding bearing portion is a resin layer formed of a resin composition. .   2. The rolling bearing device according to claim 1, wherein an outer diameter portion of the sliding bearing portion is formed of a metal base material, and the resin layer is formed as an inner diameter portion on one surface of the metal base material.   The resin layer is formed by forming a porous layer made of a sintered metal on one surface of the metal base material, and impregnating and coating the resin composition on the porous layer. The rolling bearing device according to claim 2.   The rolling bearing device according to claim 3, wherein the surface of the metal base material on which the porous layer is formed is plated equivalent to the sintered metal.   The sliding bearing portion has a flange that covers an end surface of an inner ring of the rolling bearing portion on one side in a width direction, and the resin layer is formed on an opposite surface of the flange to the inner ring side. The rolling bearing device according to any one of claims 1 to 4.   The rolling bearing device according to any one of claims 1 to 5, wherein the sliding bearing portion is removable from an inner ring of the rolling bearing portion.   The rolling bearing device according to any one of claims 1 to 6, wherein the rolling bearing device supports a mating shaft used in a construction machine.   The rolling bearing device according to any one of claims 1 to 7, wherein the resin composition contains a polytetrafluoroethylene resin as a main component.   9. The rolling bearing device according to claim 8, wherein the resin composition includes at least one synthetic resin selected from a polyimide resin and a polyphenylene sulfide resin, a granular inorganic filler, and carbon fibers.   The blending ratio of each component in the resin composition is 5-30% by volume for the synthetic resin, 3-30% by volume for the granular inorganic filler, 1-15% by volume for the carbon fiber, and the remainder for the polytetrafluoro. The rolling bearing device according to claim 9, wherein the rolling bearing device is an ethylene resin.

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