JP2006125482A - Seal member and bearing using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seal member having improved sealing performance and sliding property in environment where no lubricating oil exists or at a high friction speed, and to provide a bearing using the same. <P>SOLUTION: The seal member to be used for a sliding seal portion has a surface communication hole rate of 30-90%. It comprises a resin porous body formed of a resin or a resin composition having the resin blended with a blend material, and impregnated with lubricating oil. The resin composition has a continuous working temperature of 100°C or higher, specified by UL-746B. The resin porous body has communication holes which are formed by molding the resin composition blended with a pore forming material into a molding and then dissolving the pore forming material and extracting the pore forming material from the molding using solvent which does not dissolve the resin composition. The bearing uses the seal material for a contact seal structure part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a seal member used for a seal portion that prevents intrusion of dust while sliding, and a bearing using the seal member, in particular, a rolling bearing.

Rolling bearings used in electrical equipment such as office equipment, acoustic equipment, information equipment, measuring equipment, or automotive electrical equipment prevent dust from entering the raceway from the outside and are filled inside. In order to prevent leakage of lubricating oil or grease, it is common to have a contact seal structure.
Generally, a soft resin such as rubber or polyamide and an oil-impregnated felt are frequently used for the contact seal member.
It is known that by blending acrylonitrile butadiene rubber with polytetrafluoroethylene resin powder and thermosetting resin powder as a seal member, it exhibits sliding properties superior to conventional rubber seals while ensuring sealing performance ( Patent Document 1).
An example of improving the wear resistance of rubber and surrounding contamination of oil-impregnated felt by using a material made by impregnating ultra-high molecular weight polyethylene and lubricating oil into a porous body such as wool felt as a seal member for rolling bearings is known. (Patent Document 2).
In addition, by using foamed urethane rubber containing 30 to 80% lubricating oil as a seal member for linear bearings, dust can be prevented from entering the bearings, while supplying lubricating oil to the bearings and improving durability. An example is known (Patent Document 3).

However, conventional rubber seals and resin seals such as polyamide show excellent sealing performance and sliding characteristics in an environment lubricated with lubricating oil, but there is no lubricating oil, high friction speed, or large vibration. In such an environment where a sufficient oil film cannot be formed, there is a problem that the seal portion is greatly worn and the sealing performance cannot be maintained for a long time.
In addition, the sealing member described in Patent Document 1 can exhibit self-lubricating properties and maintain a relatively long-term sealing property even when no lubricating oil is present. Because of lubrication, there is a problem that the progress of wear is accelerated when the friction speed is high.
In addition, the ultrahigh molecular weight polyethylene described in Patent Document 2 and the urethane foam rubber described in Patent Document 3 are both subject to thermal degradation and melt wear as bearing seal members used under severe conditions such as high-speed rotation and high-temperature atmosphere. There is a problem that it cannot be adopted because it becomes a problem.
JP 2001-17110 A JP 2001-98289 A JP-A-11-351252

  The present invention has been made to address such problems, and provides a seal member that exhibits excellent sealing properties and sliding characteristics even in environments where there is no lubricating oil and when the friction speed is high, It is an object of the present invention to provide a seal member optimum for a bearing used under severe conditions such as high-speed rotation and high-temperature atmosphere, and a bearing using the seal member.

The seal member of the present invention is a seal member used for a seal part accompanied by sliding, the seal member having a surface communication porosity of 30% to 90%, and a resin or a compounded material in the resin Lubricating oil is applied to a resin porous body formed by molding a resin composition (hereinafter, “resin or a resin composition obtained by blending a compound with the resin”) is abbreviated as “resin composition”. It is characterized by being impregnated.
The resin composition is characterized in that the continuous use temperature specified in UL-746B is 100 ° C. or higher.
The resin porous body is molded by using the solvent that dissolves the pore forming material and does not dissolve the resin composition after the resin composition containing the pore forming material is molded into a molded body. It has the communicating hole obtained by extracting the said pore formation material from a body, It is characterized by the above-mentioned.
Here, the continuous use temperature specified in UL-746B is a standard for long-term physical property evaluation of plastics materials. When plastics materials are used in the atmosphere at a constant temperature for 100,000 hours, they are mechanical. This is the temperature at which the initial physical properties such as characteristics drop to 50%. In other words, if the plastics material is used at a temperature lower than the continuous use temperature of the plastics material, the physical property value exceeding 50% of the initial physical property value can be maintained even after a usage time of 100,000 hours. Represent.
The sealing member includes all sealing devices (seal) classified into a static seal such as a gasket and a dynamic seal such as a packing. The seal member of the present invention is particularly used for a seal member of a rolling bearing.

The bearing of the present invention is a bearing having a contact seal structure part for sliding and preventing leakage of the lubricant, and the seal member used for the contact seal structure part is the seal member. It is characterized by that.
The bearing is a rolling bearing.

  Since the sealing member of the present invention is formed by impregnating a resin porous body having 30% to 90% surface communication holes with a lubricating oil, it has excellent sealing properties even in an environment where the lubricating oil is not present and when the friction speed is high. Exhibits sliding characteristics. It can also be suitably used for bearings used under severe conditions such as high-speed rotation and high-temperature atmosphere, prevents dust from entering, and prevents the lubricant in the bearings from being scattered outside.

An example in which the seal member according to the present invention is applied to a rolling bearing is shown in FIG. FIG. 1 is a cross-sectional view of a deep groove ball bearing using a seal member.
In the deep groove ball bearing 1, an inner ring 2 having an inner ring rolling surface 2a on an outer peripheral surface and an outer ring 3 having an outer ring rolling surface 3a on an inner peripheral surface are arranged concentrically, and the inner ring rolling surface 2a and the outer ring rolling surface are arranged. Several rolling elements 4 are arrange | positioned between 3a. Sealers 6 that are fixed to the cage 5, the outer ring 3, and the like that hold the plurality of rolling elements 4 are provided in the axially opposite end openings 8a, 8b of the inner ring 2 and the outer ring 3, respectively. Grease 7 is sealed at least around the rolling element 4.
The deep groove ball bearing 1 has a contact seal structure including an inner ring 2, an outer ring 3, a seal member 6, and grease 7. The seal member 6 is a resin porous body having a communication hole, and slides with the inner ring 2 and seals the sealed grease 7 so as not to leak out of the bearing from the axial end openings 8a and 8b of the inner ring 2. .

Since the sealing member of the present invention is a resin porous body having communication holes, the resin porous body enables impregnation of the lubricating oil and supply of the lubricating oil to the sealing surface through the communication holes. Therefore, the lubricity of the seal member surface can be maintained for a long time.
Lubricating oil is not kneaded into the sealing member, but is impregnated in the communication hole, so that fluidity of the lubricating oil to the sealing surface is ensured through the communication hole. When the oil is consumed, the impregnated lubricating oil is always supplied to the sealing surface through the communication hole, so that 60% or more of the total amount of the impregnated lubricating oil can be used as the lubricating oil.
In addition, that it can utilize as lubricating oil means that this lubricating oil can ooze out to the said resin porous body surface, and can provide lubricity to a sealing surface in each use and use conditions.

When considering the porosity of the porous material having pores inside, the porous material is an aggregate of a plurality of spheres in which one sphere is gathered, and a space existing in the gap between the individual spheres. Considering that it consists of pores, face-centered cubic lattice and hexagonal close-packed packing are the most densely packed spheres by point contact, and their filling rate is (volume of sphere ÷ volume of circumscribed cube) ÷ (positive Calculated by the height of the triangle divided by the base) divided by the height of the regular tetrahedron divided by one side, both are 74%. The communication porosity defined as (100-filling rate) is 26%.
The above calculation is a case where spheres of the same size are considered. However, when spheres of a plurality of sizes are filled, the filling rate becomes larger than the hexagonal close-packed filling, and the communication porosity becomes smaller.
Further, when the powdered spherical resin composition particles are sintered after compression molding, there is no point contact, and the spherical resin composition particles are deformed and brought into surface contact. For this reason, a filling rate becomes larger than hexagonal close-packed filling, and a communicating porosity becomes smaller. For this reason, the communication pore ratio of the conventional sintered resin composition molded body is limited to about 20%.

上記、数１において、各符号の意味を以下に示す。
Ｖ；洗浄前成形体の体積
ρ；洗浄前成形体の密度
Ｗ；洗浄前成形体の重量
Ｖ₁；樹脂組成物の体積
ρ₁；樹脂組成物の密度
Ｗ₁；樹脂組成物の重量
Ｖ₂；気孔形成材の体積
ρ₂；気孔形成材の密度
Ｗ₂；気孔形成材の重量
Ｖ₃；洗浄後の樹脂多孔質体の体積
Ｗ₃；洗浄後の樹脂多孔質体の重量
Ｖ'₂；洗浄後に樹脂多孔質体に残存する気孔形成材の体積 The communication pore ratio in the present invention refers to the ratio of the total volume of pores continuous with each other in the resin composition molded body to the volume of the resin composition molded body.
Specifically, the communication porosity was calculated by the method shown in Equation (1) in Equation 1.

In the above Equation 1, the meaning of each symbol is shown below.
V; Volume ρ of molded body before cleaning; Density W of molded body before cleaning; Weight V _{1 of} molded body before cleaning; Volume ρ _{1 of} resin composition; Density W _{1 of} resin composition; Weight V _{2 of} resin composition. ; Volume of pore forming material ρ ₂ ; Density of pore forming material
W ₂ ; Weight of pore forming material V ₃ ; Volume of resin porous body after washing W ₃ ; Weight of resin porous body after washing V ′ ₂ ; Volume of pore forming material remaining in resin porous body after washing

In the present invention, a resin porous body having a communicating porosity of preferably 30% to 90%, more preferably 40% to 70% is obtained by the production method described below. If it is less than 30%, the characteristic excellent sliding characteristics by oil lubrication cannot be shown. If it exceeds 90%, the desired mechanical strength cannot be obtained.
As the resin used for the resin composition in the present invention, resin powder and pellets such as thermoplastic resin, thermosetting resin, elastomer or rubber can be used. The particle size and shape of the resin powder and pellets are not particularly limited when melt molding because they are kneaded with the pore forming material at the time of melting. In the case of dry blending and compression molding as it is, those of 1 to 500 μm are preferable.
Examples of the thermoplastic resin or thermosetting resin include polyethylene resins such as low density polyethylene, high density polyethylene, and ultrahigh molecular weight polyethylene, modified polyethylene resins, water-crosslinked polyolefin resins, polyamide resins, aromatic polyamide resins, polystyrene resins, Polypropylene resin, silicone resin, urethane resin, polytetrafluoroethylene resin, chlorotrifluoroethylene resin, tetrafluoroethylene / hexafluoropropylene copolymer resin, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer resin, vinylidene fluoride resin , Ethylene / tetrafluoroethylene copolymer resin, polyacetal resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyphenylene ether resin, Recarbonate resin, aliphatic polyketone resin, polyvinylpyrrolidone resin, polyoxazoline resin, polyphenylene sulfide resin, polyethersulfone resin, polyetherimide resin, polyamideimide resin, polyetheretherketone resin, thermoplastic polyimide resin, thermosetting Examples thereof include a functional polyimide resin, an epoxy resin, a phenol resin, an unsaturated polyester resin, and a vinyl ester resin. Moreover, the mixture of 2 or more types of materials chosen from the said synthetic resin, ie, a polymer alloy, etc. can be illustrated.

  Examples of the elastomer or rubber include acrylonitrile butadiene rubber, isoprene rubber, styrene rubber, butadiene rubber, nitrile rubber, chloroprene rubber, butyl rubber, acrylic rubber, silicone rubber, fluorine rubber, ethylene propylene rubber, chlorosulfonated polyethylene rubber, chlorinated Examples thereof include vulcanized rubbers such as polyethylene rubber and epichlorohydrin rubber; and thermoplastic elastomers such as polyurethane elastomer, polyester elastomer, polyamide elastomer, polybutadiene elastomer, and soft nylon elastomer.

The resin composition used for the seal member of the present invention is a resin composition in which a compounding material is blended with a resin, and the continuous use temperature defined by UL-746B is 100 ° C. or higher.
The sealing member of the present invention is a sealing member obtained by impregnating a resin porous body having a continuous porosity of 30% to 90% made of a resin composition having a continuous use temperature of 100 ° C. or higher with a lubricating oil. As a seal member for bearings used under severe conditions such as high-speed rotation and high-temperature atmosphere, it exhibits excellent sealing performance and high wear resistance.

  In the present invention, the resin from which the resin composition having a continuous use temperature of 100 ° C. or more is obtained includes polyimide resin, polyamideimide resin, polyether ether ketone resin, polytetrafluoroethylene resin, polyphenylene sulfide resin, polyamide 66 resin, polyamide 46. Resin, polyamide 12 resin, polyamide 6T resin, polyamide 9T resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polyether sulfone resin, polycarbonate resin, phenol resin, unsaturated polyester resin, vinyl ester resin, epoxy resin, etc. it can.

The resin that can be used in the resin composition in the present invention is not limited to the above-mentioned resin. Even if the continuous use temperature is less than 100 ° C., the continuous use temperature can be obtained by blending the compounding material. Any resin can be used as long as it becomes a resin composition having a temperature of 100 ° C. or higher.
Compounding materials that can improve the continuous use temperature include fibrous compounding materials such as carbon fiber (CF) and glass fiber, spherical compounding materials such as spherical silica and spherical carbon, scaly compounding materials such as mica and talc, titanium Examples thereof include fine fiber compounding materials such as potassium acid whisker. These can be blended alone or in combination.
The addition amount of the compounding material that can be used in the present invention is preferably 1 to 60% by volume, desirably 3 to 30% by volume, based on the total amount including the resin composition and the pore-forming material. If it is less than 1% by volume, there is no effect of improving the continuous use temperature, and if it exceeds 60% by volume, the mechanical strength decreases. In addition, sliding reinforcing materials such as calcium phosphate and calcium sulfate can be blended.

The resin porous body that can be used in the present invention uses a solvent that dissolves the pore-forming material and does not dissolve the resin composition after molding the resin composition containing the pore-forming material into a molded body. The pore-forming material is extracted from the molded body. For example, a water-soluble powder B having a melting point Y ° C. higher than X ° C. is blended with the resin composition A having a molding temperature X ° C., and molded at X ° C. to form a molded body, and then water-soluble than the molded body. Powder B is extracted with water to obtain a porous body. Further, for the purpose of improving the moldability of the resin composition A, a pore-forming material that is solid at normal temperature is dispersed in the resin composition A, and molded at a temperature at which the pore-forming material melts to produce a molded body, A porous resin body can be obtained by forming pores by washing with a solvent that dissolves the pore-forming material.
In addition, the manufacturing method of a resin porous body is not restricted to this, The arbitrary methods used as the communicating porosity of 30%-90% are employable.

In the present invention, the pore-forming material uses a substance having a melting point higher than the molding temperature of the resin composition, but is not limited thereto, and a substance having a melting point higher than the molding temperature of the resin composition and the resin composition A substance having a melting point lower than the molding temperature of the product can be used in combination.
As the pore-forming material, any substance that can be extracted from a molded body by using a solvent that does not dissolve the resin composition after being blended into the resin composition to form a molded body can be used.
The pore-forming material is preferably an inorganic salt compound, an organic salt compound, or a mixture thereof, and particularly preferably a water-soluble substance that facilitates the washing and extraction process. Further, an alkaline substance, preferably a weak alkali salt that can be used as a rust preventive agent can be used. Examples of the weak alkali salt include organic alkali metal salts, organic alkaline earth metal salts, inorganic alkali metal salts, inorganic alkaline earth metal salts, and the like. It is preferable to use an organic alkali metal salt or an organic alkaline earth metal salt because even when the unextracted component falls off, it is relatively soft and hardly damages the rolling surface and the sliding surface. In addition, you may use these metal salts 1 type or in mixture of 2 or more types. In addition, it is preferable to use a water-soluble weak alkali salt because inexpensive water can be used as a cleaning solvent, and waste liquid treatment at the time of pore formation is facilitated.
Water-soluble organic alkali metal salts that can be suitably used in the present invention include sodium benzoate (melting point 430 ° C.), sodium acetate (melting point 320 ° C.) or sodium sebacate (melting point 340 ° C.), sodium succinate, stearic acid Sodium etc. are mentioned. Sodium benzoate, sodium acetate, or sodium sebacate is particularly preferred because of its high melting point, compatibility with various resin compositions, and high water solubility.
Examples of the inorganic alkali metal salt include potassium carbonate, sodium carbonate, sodium silicate, sodium triphosphate, sodium pyrophosphate, sodium molybdate, potassium molybdate, and sodium tungstate.

  In the present invention, the ratio of the pore-forming material is 30% by volume to 90% by volume, preferably 40% by volume to 70% by volume with respect to the total amount including the resin composition and the pore-forming material. The consistency with the porosity of 40% to 70% was adopted and the volume was set to 40 vol% to 70 vol%, and your application number 2004-838 was also 40 vol% to 70 vol%. If it is less than 30% by volume, the pores of the resin porous body are difficult to become continuous pores, and if it exceeds 90% by volume, the desired mechanical strength cannot be obtained.

In the present invention, the mixing method of the resin composition and the pore forming material is not particularly limited, and a kneading method generally used for mixing the resin composition such as dry blending and melt kneading can be applied.
In addition, it is possible to use a method in which the pore-forming material is dissolved in a liquid solvent to form a transparent solution, and then the resin composition powder is dispersed and mixed in this solution, and then the solvent is removed.
The method of dispersing and mixing is not particularly limited as long as it can be mixed in a liquid, and examples thereof include a ball mill, an ultrasonic disperser, a homogenizer, a juicer mixer, and a Henschel mixer. It is also effective to add a small amount of a surfactant in order to suppress separation of the dispersion. At the time of mixing, the amount of solvent is secured so that the pore forming material is completely dissolved by mixing.
As a method for removing the solvent, methods such as heat evaporation, vacuum evaporation, bubbling with nitrogen gas, dialysis, and freeze-drying can be used. Since the method is easy and the equipment is inexpensive, it is preferable to remove the liquid solvent by heat evaporation.
Regarding molding of a mixture in which a pore molding material is blended with a resin composition, any molding method such as compression molding, injection molding, extrusion molding, blow molding, vacuum molding, transfer molding or the like can be adopted. Moreover, in order to improve workability | operativity before shaping | molding, you may process into a pellet, a prepreg, etc.

Extraction of the pore-forming material from the obtained molded body is carried out by washing the molded body with a solvent that dissolves the pore-forming material and does not dissolve the resin composition.
As the solvent, for example, water and alcohol solvents, ester solvents, ketone solvents, and the like can be used as solvents compatible with water. Among these, the resin composition and the pore forming material are appropriately selected according to the above conditions. These solvents may be used alone or in combination of two or more. It is preferable to use water because of its advantages such as easy waste liquid treatment and low cost.
By performing the extraction treatment, the portion filled with the pore forming material is dissolved, and a porous resin body having pores formed in the dissolved portion is obtained.

Example 1:
Mixing ultra high molecular weight polyethylene resin powder (Miperon XM220 manufactured by Mitsui Chemicals, Inc.) and sodium benzoate powder (reagent manufactured by Wako Pure Chemical Industries, Ltd.), which is a pore forming material, in a mixer at a volume ratio of 50:50 for 5 minutes. Then, heat compression molding (360 ° C. × 30 minutes) was performed, and a predetermined test piece was obtained by cutting. Thereafter, the test piece was washed with warm water at 80 ° C. with an ultrasonic cleaner to elute the pore-forming material and dried to obtain a porous resin body having a communication porosity of 48%. This was impregnated with a lubricating oil (turbine oil, ISO VG68) in vacuum to obtain a resin porous body test piece. The oil content is 45% of the total volume of the porous resin specimen.

Example 2:
After mixing PEEK resin powder (150 PF manufactured by Victrex) and sodium benzoate powder (reagent manufactured by Wako Pure Chemical Industries, Ltd.), which is a pore-forming material, in a mixer at a volume ratio of 50:50 for 5 minutes, heat compression molding ( 360 ° C. × 30 minutes), and a predetermined test piece was obtained by cutting. Thereafter, the test piece was washed with warm water at 80 ° C. with an ultrasonic cleaner to elute the pore-forming material and dried to obtain a porous resin body having a communication porosity of 48%. This was impregnated with a lubricating oil (turbine oil, ISO VG68) in vacuum to obtain a resin porous body test piece. The oil content is 45% of the total volume of the porous resin specimen.

Example 3:
In a volume ratio of 40:10:50, PEEK resin powder (150 PF manufactured by Victrex), carbon fiber (MLD100 manufactured by Toray Industries, Inc.), sodium benzoate powder (reagent manufactured by Wako Pure Chemical Industries, Ltd.) which is a pore forming material After mixing for 5 minutes with a mixer, heat compression molding (360 ° C. × 30 minutes) was performed, and a predetermined test piece was obtained by cutting. Thereafter, the test piece was washed with warm water at 80 ° C. with an ultrasonic cleaner to elute the pore-forming material and dried to obtain a porous resin body having a communication porosity of 48%. This was impregnated with a lubricating oil (turbine oil, ISO VG68) in vacuum to obtain a resin porous body test piece. The oil content is 45% of the total volume of the porous resin specimen.

Comparative Example 1:
A sheet of acrylonitrile butadiene rubber (thickness 2 mm) was punched to obtain a resin molded body test piece having a predetermined shape.

Comparative Example 2:
Using a roll mixer adjusted to a roll interval of 5 to 10 mm, mix acrylonitrile butadiene rubber and a basic additive (inorganic filler, anti-aging agent, carbon sulfur vulcanization accelerator) in an appropriate amount. 30 parts by weight of thermoplastic resin powder (Bellepar R600 manufactured by Kanebo Co., Ltd.) and 50 parts by weight of polytetrafluoroethylene resin powder (KT300M manufactured by Kitamura Co., Ltd.) were mixed with 100 parts by weight of the mixture. The mixture was adjusted to 1 mm and mixed (thinned) to obtain a compound. Further, the obtained compound was heat compression molded at 170 ° C. to obtain a sheet having a thickness of 2 mm, and then a molded resin test piece having a predetermined shape was obtained by punching.
Comparative Example 3:
The wool felt was made into a predetermined shape by punching and impregnated with lubricating oil (turbine oil, ISO VG68) to obtain a wool felt test piece.

Comparative Example 4:
Lubricating oil (turbine oil, ISO VG68) and ultrahigh molecular weight polyethylene resin powder (Miperon XM220 manufactured by Mitsui Chemicals, Inc.) are mixed at a volume ratio of 90:10 and impregnated into a wool felt that has a predetermined shape by punching. And calcined at 150 ° C. to obtain a wool felt test piece.

Comparative Example 5:
Ultra high molecular weight polyethylene resin powder (Miplon XM220 manufactured by Mitsui Chemicals, Inc.) and sodium benzoate powder (reagent manufactured by Wako Pure Chemical Industries, Ltd.), which is a pore-forming material, are mixed in a mixer at a volume ratio of 70:30 for 5 minutes. Then, heat compression molding (360 ° C. × 30 minutes) was performed, and a predetermined test piece was obtained by cutting. Thereafter, the test piece was washed with warm water at 80 ° C. with an ultrasonic cleaner to elute the pore-forming material and dried to obtain a porous resin body having a communication porosity of 12%. This was impregnated with a lubricating oil (turbine oil, ISO VG68) in vacuum to obtain a resin porous body test piece. The oil content is 11% of the total volume of the porous resin specimen.

Sliding test:
Resin porous body specimens obtained in Examples 1 to 3 and Comparative Example 5, resin molded article specimens obtained in Comparative Example 1 and Comparative Example 2, and wool felt test obtained in Comparative Examples 3 and 4 In order to investigate the friction and wear characteristics of the piece, a ring-on-disk test was conducted under the following test conditions to evaluate the sliding characteristics. The results are shown in Table 1.
Contact pressure: 1 MPa, speed: 64 m / min, time: 20 hours Test piece: φ17 mm × φ21 mm × thickness 2 mm
Opposite material: φ33 mm × thickness 6 mm, SUJ2 (surface roughness Ra 0.5μm)
Measurement item: Specific wear (× 10 ^-8 mm ³ / (N · m))
： “○” when the other material is damaged, “×” when the other material is not damaged

表１において、比較例１のアクリロニトリルブタジエンゴムは試験開始数分後には異常摩耗のため停止した。比較例２は、ゴムでありながら固体潤滑剤の自己潤滑性により異常摩耗することはなかったが、摩耗は大きく、また摩擦係数も高い。
また、羊毛フェルトが基材となっている比較例３および比較例４の場合、摺動によりフェルトがほぐれて解体するので耐摩耗性が低く、また、羊毛の繊維が相手材を損傷させる。
また、比較例５は連通孔率 12％と低いので含油率が低いため、同じ超高分子ポリエチレン樹脂系の実施例１よりも摩耗が大きく、また摩擦係数も高い。

In Table 1, the acrylonitrile butadiene rubber of Comparative Example 1 was stopped due to abnormal wear after several minutes from the start of the test. Although Comparative Example 2 was rubber, it did not wear abnormally due to the self-lubricating property of the solid lubricant, but the wear was large and the friction coefficient was high.
Further, in Comparative Examples 3 and 4 in which the wool felt is the base material, the felt is loosened and disassembled by sliding, so that the wear resistance is low, and the wool fiber damages the counterpart material.
Further, Comparative Example 5 has a low oil content because it has a low communication pore ratio of 12%, and therefore wear is larger and the friction coefficient is higher than Example 1 of the same ultra-high molecular weight polyethylene resin system.

  Since the seal member of the present invention is a seal member obtained by impregnating a resin porous body having a communication porosity of 30% to 90% with a lubricating oil, it is excellent even in an environment where the lubricating oil is not present or when the friction speed is high. It exhibits excellent sealing properties and high wear resistance, and can be suitably used as a seal member for bearings used under severe conditions such as high-speed rotation and high-temperature atmosphere.

It is sectional drawing of the deep groove ball bearing which shows a sealing member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Deep groove ball bearing 2 Inner ring 3 Outer ring 4 Rolling element 5 Cage 6 Seal member 7 Grease

Claims (5)

  A sealing member for use in a sealing part with sliding, the sealing member having a surface communication porosity of 30% to 90%, and a resin composition comprising a resin or a compounding material mixed with the resin A sealing member formed by impregnating a porous resin body formed by molding a lubricating oil.   The sealing member according to claim 1, wherein the resin composition has a continuous use temperature defined by UL-746B of 100 ° C or higher.   The resin porous body is molded by using the solvent that dissolves the pore forming material and does not dissolve the resin composition after the resin composition containing the pore forming material is molded into a molded body. The sealing member according to claim 1, further comprising a communication hole obtained by extracting the pore forming material from a body.   A bearing having a contact seal structure for sliding and preventing leakage of a lubricant, wherein the seal member used in the contact seal structure is claim 1, claim 2 or claim 3. A bearing comprising the sealing member described above.   The bearing according to claim 4, wherein the bearing is a rolling bearing.

Images