JP2006029346A - Rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing in which in cases where grease containing an urea compound is encapsulated in a rolling bearing, an elastic body of a hermetically-sealed plate acting as a sealing member is less deteriorated even when a bearing ambient temperature becomes high and thereby good seal performance is allowed to hold over the long term, thus realizing excellence in reliability and endurance. <P>SOLUTION: There is provided the rolling bearing used for a supporting member for supporting a drive shaft in a freely rotatable manner at a vehicle body side. The rolling bearing is equipped with an outer race and inner race, a plurality of rolling elements intervened between the inner and outer races, grease containing the urea compound encapsulated in a periphery of the rolling elements, and a sealing member provided at openings of both ends in an axial direction of the inner and outer races to encapsulate the grease. The sealing member includes a molded rubber body in contact with at least the grease. The molded rubber body is formed of a fluorocarbon-rubber composite that contains tetrafluoroethylene, propylene and cross-linking monomers consisting of unsaturated hydrocarbon with the number of carbons 2 to 4 created by replacing part of hydrogen atoms with fluorine atoms and can be vulcanized. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rolling bearing used for a support member that supports a drive shaft of an automobile on the vehicle body side, and more particularly to a rolling bearing for a constant velocity joint support member and a center support member.

In a motor vehicle, a drive shaft that transmits the driving force of an engine to each wheel is roughly classified into a propeller shaft and a drive shaft according to the transmission part. For automobiles, front engine / front drive vehicle (FF vehicle), front engine / rear drive vehicle (FR vehicle), four wheel drive vehicle (4WD vehicle), rear engine / rear drive vehicle (RR vehicle), etc. The propeller shaft is mainly used in FR vehicles and 4WD vehicles. FIG. 3 shows an outline of a drive shaft in a 4WD vehicle.
As shown in FIG. 3, the propeller shaft 9 is a rotating shaft that transmits the driving force of the engine 12 from the transmission 10 to the final reduction gear 11. Consists of a constant velocity joint that can transmit rotation even if the axis crossing angle changes, and a spline and a tube that can expand and contract in the axial direction in order to respond to changes in the relative position of the transmission 10 and the final reduction gear 11. Has been. The propeller shaft 9 is basically a two-joint type, but depending on the structure and required performance of the vehicle, the shaft may be divided into a three-joint type and a four-joint type. A center support member 13 is used as means for supporting the shaft on the vehicle body side while allowing vibration of the propeller shaft.
An example of the center support member 13 is shown in FIG. The center support member 13 has a cylindrical outer ring 15 disposed outside the cylindrical inner ring 14 at a predetermined interval, and a cross section is substantially between the outer ring 15 and the inner ring 14. A U-shaped elastic member 16 is arranged and configured. By attaching the inner ring 14 side of the center support member 13 configured as described above to the propeller shaft 9 side via the rolling bearing 1 and attaching the outer ring 15 side to the bracket on the vehicle body side, the propeller shaft 9 is attached. Anti-vibration support for rotation.

On the other hand, as shown in FIG. 3, the drive shaft is a rotating shaft that transmits driving force from the transmission or the final reduction gear to the wheels, and is divided into a front drive shaft 17a and a rear drive shaft 17b. Since the front drive shaft 17a requires a large bending angle commensurate with wheel steering, a fixed constant velocity joint 18a having an allowable bending angle of about 40 ° or more is used for the wheel side joint. The transmission or the final deceleration side joint used in combination needs to absorb the movement of the suspension. For example, a sliding type constant velocity joint 18b that can expand and contract in the axial direction although the allowable angle is not large is used.
In the case of a normal horizontal engine type, the drive shaft from the engine is unequal. Since unequal length shafts have different dynamic elasticity, handle operability is deteriorated. In order to prevent this, the intermediate drive shaft 17c is inserted as shown in FIG. 3, and the intermediate drive shaft 17c is supported on the vehicle body side near the constant velocity joint connecting portion by the constant velocity joint support member 19.
FIG. 5 shows an enlarged partial sectional view in the vicinity of the constant velocity joint support member 19. As shown in FIG. 5, the constant velocity joint support member 19 rotatably supports an intermediate drive shaft 17 c connected to the constant velocity joint 18 on the vehicle body side via the rolling bearing 1.

Urea grease is mainly used for lubrication of the rolling bearing for the constant velocity joint support member or the center support member. Fluorine grease is used when the temperature conditions are more severe, but fluorine grease is extremely expensive, and as a method to achieve the equivalent performance more economically, specific urea grease and fluorine grease are mixed. There is something.
On the other hand, when such temperature conditions are severe, the rolling bearing seal member is also required to have heat resistance. Conventionally, an acrylic rubber having relatively high heat resistance and excellent oil resistance has been used as the elastic body of the seal member.

However, the bearing for the constant velocity joint support member or the center support member may have an exhaust pipe disposed around it due to the design of the vehicle. In this case, the ambient temperature of the bearing becomes high and acrylic rubber is heat resistant. There is a problem that sex is not enough.
As a solution to this problem, it is conceivable to use fluororubber, which has better heat resistance than acrylic rubber. However, as described above, urea grease is mainly used for lubrication of the rolling bearing. Therefore, the fluororubber and urea grease are used. In combination with the above, there is a problem that the crosslinking of the fluororubber is progressed and cured by the urea compound.
When the rubber elastic body used for the seal member is cured, the sealing performance is deteriorated, which causes grease leakage and a problem of shortening the bearing life. In addition, the contact pressure at the seal surface is increased, and the rotational torque of the bearing is increased. As a result, frictional heat is generated, and the grease is further deteriorated.
Conventionally, in order to solve this problem, a terpolymer of vinylidene fluoride-tetrafluoroethylene-propylene or a terpolymer of tetrafluoroethylene-propylene is used as a fluororubber. A method of improving the durability of a rolling bearing has been proposed (see Patent Document 1). However, even when the fluororubber is used, it is difficult to suppress deterioration with time of the fluororubber depending on the design of the vehicle. There is.
JP 2001-66578 A

  The present invention has been made to cope with such a problem. In a rolling bearing used for a constant velocity joint support member or a center support member, when grease containing a urea compound is sealed, the bearing ambient temperature is It is an object of the present invention to provide a rolling bearing that has little deterioration of an elastic body of a sealing plate that is a sealing member even at high temperatures, maintains good sealing performance for a long time, and is excellent in reliability and durability.

  The rolling bearing of the present invention is a rolling bearing used for a support member that rotatably supports a drive shaft on the vehicle body side, and includes an inner ring and an outer ring, a plurality of rolling elements interposed between the inner ring and the outer ring, and the above-described rolling element. A grease containing a urea compound encapsulated around the moving body, and a seal member provided at both ends of the inner ring and the outer ring in the axial direction for sealing the grease. A rubber molded body that contacts grease, and the rubber molded body is made of tetrafluoroethylene, propylene, and an unsaturated hydrocarbon having 2 to 4 carbon atoms in which a part of hydrogen atoms are substituted with fluorine atoms. It is a molded article of a vulcanizable fluororubber composition containing a monomer.

The support member is a constant velocity joint support member that supports a drive shaft of a front engine / front drive vehicle, a rear engine / rear drive vehicle, or a four-wheel drive vehicle.
The support member may be a center support member that supports a propeller shaft of a front engine / rear drive vehicle or a four-wheel drive vehicle.

The crosslinking monomer is trifluoroethylene, 3,3,3-trifluoropropene-1,1,2,3,3,3-pentafluoropropene, 1,1,3,3,3-penta. It is at least one monomer selected from fluoropropylene and 2,3,3,3-tetrafluoropropene.
The fluororubber composition contains vinylidene fluoride.

The rolling bearing of the present invention can be vulcanized containing tetrafluoroethylene, propylene, and a crosslinking monomer composed of an unsaturated hydrocarbon having 2 to 4 carbon atoms in which some of hydrogen atoms are substituted with fluorine atoms. Since the sealing member is formed from a molded product of a fluororubber composition, there is little deterioration in physical properties even when immersed in grease containing a urea compound, and leakage of the grease can be effectively prevented.
Therefore, when the rolling bearing is used as a constant velocity joint support member or a center support member, the durability of the bearing can be improved even when the ambient temperature becomes, for example, -40 ° C to 150 ° C. it can.

The fluororubber composition that can be used in the present invention comprises tetrafluoroethylene, propylene, and a crosslinking monomer comprising an unsaturated hydrocarbon having 2 to 4 carbon atoms in which some of the hydrogen atoms are substituted with fluorine atoms. And a vulcanizable fluororubber composition comprising a copolymer.
Examples of the crosslinking monomer composed of an unsaturated hydrocarbon having 2 to 4 carbon atoms in which a part of hydrogen atoms are substituted with fluorine atoms include trifluoroethylene, 3, 3, 3-trifluoropropene-1, 1, 2, 3, 3, 3-pentafluoropropene, 1, 1, 3, 3, 3-pentafluoropropylene, 2, 3, 3, 3-tetrafluoropropene are mentioned. A preferred crosslinking monomer is 3,3,3-trifluoropropene-1.

  As a fourth component in the copolymer that can be used in the present invention, vinylidene fluoride, chlorotrifluoroethylene, perfluoro (alkyl vinyl) ether, perfluoro (alkoxy vinyl) ether, perfluoro (alkoxyalkyl vinyl) ether, perfluoroalkyl alkenyl ether, A perfluoroalkoxy alkenyl ether etc. can be mix | blended.

The components constituting the fluororubber composition are 45 to 80% by weight, preferably 50 to 78% by weight, more preferably 65 to 78% by weight, and 10 to 10% propylene with respect to the whole fluororubber. 40% by weight, preferably 12-30% by weight, more preferably 15-25% by weight, and 0.1-15% by weight of crosslinking monomer, preferably 2-10% by weight, more preferably 3-6% by weight %.
When vinylidene fluoride is copolymerized, the vinylidene fluoride content is 2 to 20% by weight, preferably 10 to 20% by weight. If it exceeds 20% by weight, the resistance to urea compounds decreases.

This fluororubber production method is disclosed in, for example, International Publication No. WO02 / 092683, and is produced by an emulsion polymerization method or a suspension polymerization method.
In order to vulcanize these fluororubbers, vulcanization accelerators selected from polyhydroxy (polyol) vulcanizing agents, quaternary ammonium salts, fourth phosphonium salts, third sulfonium salts, etc., calcium hydroxide and magnesium oxide Etc., fillers such as carbon black, clay, barium sulfate, calcium carbonate and magnesium silicate, processing aids such as octadecylamine and wax, heat aging inhibitors and pigments can be blended. For example, each compounding amount is 0.1 to 20 parts by weight, preferably 0.5 to 3 parts by weight, and 0.1 to 20 parts by weight, preferably 0.5 to 3 parts by weight, of the vulcanizing agent, based on 100 parts by weight of fluororubber. 1 to 30 parts by weight, preferably 1 to 7 parts by weight, 5 to 100 parts by weight of filler, and 0.1 to 20 parts by weight of processing aid.

In addition to these, a second vulcanizing agent such as an organic peroxide compound may be added in an amount of 0.7 to 7 parts by weight, preferably 1 to 3 parts by weight. Furthermore, fillers and additives that can be blended in general rubber compositions can be used as appropriate within a range that does not impair the resistance to urea compounds and the sealing properties.
As a method for mixing or molding these compositions, a process used for general rubber processing can be adopted. After kneading with an open roll, a Banbury mixer, a kneader, various sealed mixers, etc., press molding (press vulcanization) ), Extrusion molding, injection molding, etc. In order to improve the properties, secondary vulcanization is preferably performed after molding, and this is performed by sufficiently heating in an oven (for example, 200 ° C. for 24 hours).

上記各部材は、車両の設計上、排気管がその周囲に配置される場合があり、その場合においては軸受の周囲温度が 150℃ 以上の高温となる。本発明の転がり軸受は、該部材の摺動部に使用することを主目的とするものであり、シール部材として、上述のフッ素ゴム組成物の成形体を用いて、ウレア化合物を含有するグリースを封止した転がり軸受である。 The rolling bearings for the constant velocity joint support member or center support member of the present invention are both bearings for supporting the drive shaft, and are provided at the locations shown in FIG. 3 as described above. Table 1 shows a comparison of each support site, rotation speed, support method, and ambient temperature.

In each of the above members, the exhaust pipe may be disposed around the member due to the design of the vehicle. In that case, the ambient temperature of the bearing becomes a high temperature of 150 ° C. or higher. The rolling bearing of the present invention is mainly intended for use in the sliding portion of the member, and a grease containing a urea compound is used as a sealing member by using a molded body of the above-described fluororubber composition. It is a sealed rolling bearing.

An example of the rolling bearing for the constant velocity joint support member or the center support member of the present invention is shown in FIG. FIG. 1 is a cross-sectional view of a deep groove ball bearing filled with grease.
In the deep groove ball bearing 1, an inner ring 2 having an inner ring rolling surface 2a on the outer peripheral surface and an outer ring 3 having an outer ring rolling surface 3a on the inner peripheral surface are arranged concentrically, and the inner ring rolling surface 2a and the outer ring rolling surface 3a. A plurality of rolling elements 4 are arranged between the two. 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 seal member 6 may be a rubber molded body alone or a composite of a rubber molded body and a metal plate, a plastic plate, a ceramic plate, or the like. From the viewpoint of durability and ease of fixing, a composite of a rubber molded body and a metal plate is preferable.
An example of the sealing member 6 made of a composite of a rubber molded body and a metal plate is shown in FIG. The seal member 6 is obtained by fixing a fluororubber molded body 6b to a metal plate 6a such as a steel plate. The fixing method may be either mechanical fixing or chemical fixing. As a preferable fixing method, there can be mentioned a method in which a metal plate is placed in a vulcanizing mold, and molding and vulcanization are performed and fixed at the time of vulcanization of a fluororubber molded article.

The seal member 6 can be mounted by (1) fixing one end 6c of the seal member 6 to the outer ring 3, and forming the labyrinth gap along the V groove on the seal surface of the inner ring 2 at the other end 6d. One end 6c of the member 6 is fixed to the outer ring 3, and the other end 6d is brought into contact with the V groove side surface of the seal surface of the inner ring 2. (3) One end 6c of the seal member 6 is fixed to the outer ring 3, and the other end 6d is the inner ring. 2 is contacted with the side surface of the V-groove of the sealing surface, but a low-torque structure is provided by providing a suction-preventing slit or the like in the contacting lip portion.
In any of the above mounting methods, the sealed grease 7 comes into contact with the rubber molded body 6b constituting the seal member 6. The rubber molded body 6b is formed of the above-described fluororubber molded body at least at a portion in contact with the sealed grease 7. For example, the rubber molded body 6b may be the above-described single fluororubber molded body, or a laminated body in which a conventional rubber molded body is laminated on the back surface of the above-described fluororubber molded body at a portion in contact with the grease 7.

The rolling bearing contains a urea grease containing a urea compound.
Base oils for urea grease include mineral oils such as paraffinic mineral oil and naphthenic mineral oil, synthetic hydrocarbon oils such as poly-α-olefin oil (PAO), dialkyl diphenyl ether oil, alkyl triphenyl ether oil, alkyl tetra Ether oils such as phenyl ether oils, diester oils, polyol ester oils, or ester oils such as complex ester oils, aromatic ester oils, carbonate ester oils, and the like can be used alone or mixed with each other.
Among these, alkyl diphenyl ether oil, ester oil, poly-α-olefin oil (PAO) and the like are preferable in consideration of lubrication performance at high temperature and high speed and lubrication life.

また、Ｒ₁およびＲ₃は、１価の脂肪族基、脂環族基または芳香族基をそれぞれ表す。特に、Ｒ₁およびＲ₃が脂肪族基である脂肪族ジウレアを増ちょう剤とするウレア系グリースがフッ素グリースとの混合には容易に混合するので好ましい。なお、ウレア化合物の製造方法の一例としては、ジイソシアナート化合物にイソシアナート基当量のアミン化合物を反応させて得られる。 The urea compound blended as a thickener contains a urea bond (—NHCONH—) in the molecule, and examples include diurea, triurea, tetraurea, urea urethane, and the like. A preferred urea compound is diurea having two urea bonds in the molecule, and is represented by the following chemical formula 1. R ₂ is a divalent aromatic hydrocarbon group having 6 to 15 carbon atoms, and is specifically represented by the following chemical formula 2.

R ₁ and R ₃ each represent a monovalent aliphatic group, alicyclic group or aromatic group. In particular, a urea-based grease using an aliphatic diurea in which R ₁ and R ₃ are aliphatic groups as a thickener is preferable because it is easily mixed with a fluorine grease. In addition, as an example of the manufacturing method of a urea compound, it is obtained by making an isocyanate compound equivalent to an isocyanate group react with a diisocyanate compound.

  The urea grease is preferably blended in an amount of 95 to 70% by weight of the base oil and 5 to 30% by weight of the urea compound based on the total amount of the grease. By blending in this range, the grease contained in the bearing can be adjusted to a consistency with good lubricity for a long time with less grease leakage.

When the operating temperature conditions are severe, fluorine grease can be used in combination with grease containing the above urea compound as a thickener.
A preferred example of the fluorine grease is polytetrafluoroethylene (PTFE) as a thickener and perfluoropolyether (PFPE) as a base oil.
The fluorine grease is preferably blended in an amount of 50 to 90% by weight of perfluoropolyether oil and 50 to 10% by weight of fluororesin particles based on the total amount of the grease. By blending in this range, it is possible to adjust to a preferred consistency that can reduce the torque for a long time with less leakage as the grease contained in the bearing.

  The mixing ratio (weight ratio) of urea grease and fluorine grease is preferably in the range of 30:70 to 75:25 for urea grease: fluorine grease. The most preferred components of the urea grease in combination with the fluorine grease are those in which the thickener is an aliphatic diurea, the base oil is an ester oil, the fluorine grease is a thickener PTFE, and the base oil is PFPE.

The urea-based grease and mixed grease used in the production of examples of the rolling bearings for constant velocity joint port members or center support members of the present invention, comparative examples, and seal member examples of the bearings are shown below.
(1) Urea grease 1
Made by Crububa: Asonic HQ72-102 (Thickener: aliphatic diurea, base oil: aromatic polyester oil, kinematic viscosity at 40 ° C. 100 mm ² / s)
(2) Urea grease 2
A base oil composed of a mixed oil of poly-α-olefin oil (trade name, Shinflud 601 manufactured by Nippon Steel Chemical Co., Ltd.) and alkyl diphenyl ether oil (trade name, manufactured by Matsumura Oil Co., Ltd., LB100) is prepared at a blending ratio of 20: 80% by weight. did. This base oil is divided into two liquids, and 4,4′-diphenylmethane diisocyanate is dissolved in half of the base oil, and the remaining half of the base oil has a double equivalent of 4,4′-diphenylmethane diisocyanate. Toluidine was dissolved. In addition, 4,4′-diphenylmethane diisocyanate was dissolved so as to be 20% by weight of the total amount of the grease composition as an aromatic diurea compound. After adding the p-toluidine solution while stirring the solution, stirring was continued for 30 minutes at 100 to 120 ° C. to cause the aromatic diurea compound to precipitate in the base oil. To this, 100 parts by weight of the total amount of grease was added 1 part by weight of sorbitan trioleate, 1 part by weight of sodium sebacate and 2 parts by weight of alkyldiphenylamine as an antioxidant, and the mixture was further stirred at 100 to 120 ° C. for 10 minutes. Thereafter, the mixture was cooled and homogenized with three rolls to obtain a grease composition.
(3) Mixed grease The total weight of the grease is 33% by weight of fluororesin powder (DuPont product name, Vidax) and 67% by weight of perfluoropolyether oil (DuPont product name, Krytox 240AC). After stirring, the mixture was passed through a roll mill to obtain a semi-solid fluorine grease which was “a grease using PTFE powder as a thickener and PFPE as a base oil”.
Next, with respect to the entire grease, aromatic ester oil (trade name, Asahi Denka Kogyo Co., Ltd., Prover T90) dissolves 1 mol of diisocyanate in half of 88% by weight, and dissolves 2 mol of monoamine in the remaining half of the above half amount. And then stirred for 30 minutes at 100 to 120 ° C. to react with a urea compound (a fatty acid in which R ₁ and R ₃ are aliphatic groups and R ₂ is a diphenylmethane group) Group diurea) was precipitated in the base oil. Thereafter, it was passed through a roll mill to obtain a semi-solid urea grease which was “a grease using a urea compound as a thickener and a synthetic oil as a base oil”.
40 wt% of the above fluorine grease, 59 wt% of urea grease, and 1 wt% of amine-based antirust additive based on mineral oil were mixed and stirred to obtain a mixed grease of fluorine grease and urea grease.

The rubber compositions used in the respective sealing member examples, examples, and comparative examples are shown below.
An unvulcanized rubber composition was obtained by kneading using an open roll at a roll temperature of 50 ° C. with the composition shown in Table 2. Each material used in Table 2 is shown below.
(1) Fluoro rubber 1: manufactured by DuPont Dow Elastomer Co., Ltd .; VTR8802 (with vulcanizing agent)
(2) Fluoro rubber 2: manufactured by Asahi Glass; Afras 150
(3) Fluoro rubber 3: manufactured by DuPont Dow Elastomer; A32J
(4) Acrylic rubber: Nippon Zeon Corporation; AR71
(5) Magnesium oxide: manufactured by Kyowa Chemical Industry Co., Ltd .;
(6) Calcium hydroxide: manufactured by Omi Chemical Industry Co., Ltd .; Calbit (7) Carbon 1: manufactured by Engineered Company; N990
(8) Co-crosslinking agent: Nippon Kasei Co., Ltd .; TAIC
(9) Vulcanizing agent: manufactured by Kayaku Akzo; Parkadox 14
(10) Carbon 2: Tokai Carbon Co., Ltd .; Seast 3
(11) Sulfur: manufactured by Tsurumi Chemical Co., Ltd .; Sulfax PMC
(12) Anti-aging agent: Ouchi Shinsei Chemical Co., Ltd .; NOCRACK CD
(13) Sodium stearate: manufactured by Kao Corporation; NS soap (14) potassium stearate: manufactured by NOF Corporation; Non-Sal SK-1

シール部材例１〜シール部材例５は、高温条件下、長時間の浸漬でも劣化が軽微であり、ウレア系グリースおよび混合グリースに対して優れた耐性を有していた。 Seal member example 1 to seal member example 5, comparative seal member example 1 to comparative seal member example 9
Using the unvulcanized rubber composition, a vulcanized molded product was obtained with a vulcanizing press. The actual temperature of the mold was 170 ° C, and the vulcanization time was vulcanized at 170 ° C for 12 minutes as the primary vulcanization. Subsequently, secondary vulcanization was performed in a thermostatic bath. Secondary vulcanization conditions are as follows: Formulation Examples 1 to 3 are 200 ° C. for 24 hours, and Formulation Example 4 is 170 ° C. for 4 hours.
The obtained vulcanized molded product was punched into the shape of a JIS K 6251 No. 3 test piece to prepare a test piece. The test piece was embedded and immersed in the urea grease 1, urea grease 2 and the mixed grease (170 ° C. or 200 ° C.) × 1000 hours, and the physical properties before and after immersion were measured. The measured physical properties were measured for hardness, tensile strength, tensile elongation, and volume, and evaluated for hardness change, tensile strength change rate, tensile elongation change rate, and volume change rate with respect to the physical property values before immersion. The measurement conditions were based on JIS K 6251K, JIS K 6253K, and JIS K 6258. The results are shown in Tables 3-5. In Tables 4 and 5, * indicates that measurement is impossible.

Seal member example 1 to seal member example 5 had a slight deterioration even when immersed for a long time under high temperature conditions, and had excellent resistance to urea grease and mixed grease.

Example 1
The unvulcanized rubber composition of Formulation Example 1 was molded into a steel core and a non-contact rubber seal (Fig. 2) for 6204 bearing (inner diameter: 20 mm, outer diameter: 47 mm, width: 14 mm) was obtained. It was. This was incorporated into a bearing thoroughly cleaned with petroleum benzine, and a mixed rolling grease of 38% of the total space volume was sealed inside the bearing to produce a rolling test bearing. The obtained rolling bearing was evaluated in the high temperature durability test 1. The results are shown in Table 6.
In the high temperature durability test 1, the bearing was rotated at a radial load of 67 N, a thrust load of 67 N, a rotation speed of 10000 rpm, and an ambient temperature of 220 ° C., and the time until the motor stopped due to overload was measured. The maximum test time was 1000 hours.

Example 2
The same non-contact type rubber seal as that in Example 1 was incorporated in a bearing thoroughly cleaned with petroleum benzine, and urea grease 2 having 38% of the total space volume was sealed inside the bearing to produce a rolling bearing for testing. The obtained rolling bearing was evaluated in the high temperature durability test 2 described above. The results are shown in Table 6.
In the high temperature durability test 2, the bearing was rotated at a radial load of 67 N, a thrust load of 67 N, a rotation speed of 10000 rpm, and an ambient temperature of 180 ° C., and the time until the motor stopped due to overload was measured. The maximum test time was 500 hours.

Comparative Example 1 and Comparative Example 2
Using the blending example 2 and the blending example 3, the rolling bearing for the test of the comparative example 1 and the comparative example 2 was produced similarly to the example 1. A high-temperature durability test 1 similar to that in Example 1 was performed, and the results are shown in Table 6.

実施例１および実施例２では 500 時間以上の運転が可能であり、試験後のシールも目視でクラックはみられなかった。
一方、比較例１および比較例２は実施例１に比べて、比較例３および比較例４は実施例２に比べて短時間で焼きつきが生じた。運転中のグリースの漏洩が短寿命の主な原因と思われる。なお、比較例２および比較例４の試験後のシールの接触部には多数のクラックがみられた。 Comparative Example 3 and Comparative Example 4
Using Example 2 and Example 3, rolling bearings for testing of Comparative Example 3 and Comparative Example 4 were produced in the same manner as Example 2. A high-temperature durability test 2 similar to that of Example 2 was performed, and the results are shown in Table 6.

In Example 1 and Example 2, operation for 500 hours or more was possible, and no cracks were visually observed in the seal after the test.
On the other hand, in Comparative Example 1 and Comparative Example 2, image sticking occurred in a shorter time than in Example 1, and in Comparative Example 3 and Comparative Example 4 compared with Example 2. Leakage of grease during operation seems to be the main cause of short life. In addition, many cracks were seen in the contact part of the seal | sticker after the test of the comparative example 2 and the comparative example 4. FIG.

  Since the rolling bearing of the present invention has excellent urea grease resistance, it can be suitably used as a rolling bearing for constant velocity joint port members or center support members used at high temperatures.

It is sectional drawing of the rolling bearing of this invention. It is sectional drawing of the sealing member of a rolling bearing. It is the schematic of the drive shaft in a 4WD vehicle. It is sectional drawing of a center support member. It is sectional drawing of a constant velocity joint support member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Deep groove ball bearing 2 Inner ring 3 Outer ring 4 Rolling body 5 Cage 6 Seal member 7 Grease 8 Opening 9 Propeller shaft 10 Transmission 11 Final reduction device 12 Engine 13 Center support member 14 Inner ring 15 Outer ring 16 Elastic member 17 Drive shaft 18 Constant Velocity Joint 19 Constant Velocity Joint Support Member

Claims (6)

A rolling bearing used for a support member that rotatably supports the drive shaft on the vehicle body side,
The rolling bearing includes an inner ring and an outer ring, a plurality of rolling elements interposed between the inner ring and the outer ring, grease containing a urea compound sealed around the rolling elements, and axially open ends of the inner ring and the outer ring. Provided with a sealing member for sealing the grease,
The seal member has a rubber molded body that comes into contact with at least the grease, and the rubber molded body is tetrafluoroethylene, propylene, and a non-carbon group having 2 to 4 carbon atoms in which some hydrogen atoms are substituted with fluorine atoms. A rolling bearing characterized by being a molded body of a vulcanizable fluororubber composition containing a crosslinking monomer comprising a saturated hydrocarbon.   The rolling bearing according to claim 1, wherein the support member is a constant velocity joint support member that supports a drive shaft of a front engine / front drive vehicle, a rear engine / rear drive vehicle, or a four-wheel drive vehicle.   The rolling bearing according to claim 1, wherein the support member is a center support member that supports a propeller shaft of a front engine / rear drive vehicle or a four-wheel drive vehicle.   The crosslinking monomer is trifluoroethylene, 3,3,3-trifluoropropene-1,1,2,3,3,3-pentafluoropropene, 1,1,3,3,3-pentafluoropropylene The rolling bearing according to claim 1, wherein the rolling bearing is at least one monomer selected from 2,3,3,3-tetrafluoropropene.   The rolling bearing according to any one of claims 1 to 4, wherein the fluororubber composition contains vinylidene fluoride.   The rolling bearing according to any one of claims 1 to 5, wherein the grease containing the urea compound is a mixed grease of fluorine grease and urea grease.

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