JP2005249090A - Rolling bearing for flywheel damper and flywheel damper support structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To hardly cause deterioration of a sealing material, keep good sealing performance for long time, and improve reliability and durability even when a rolling bearing for a flywheel damper filled with grease containing urea compound is used at a high temperature. <P>SOLUTION: This rolling bearing for a flywheel damper includes: an inner ring; an outer ring; a plurality of rolling elements interposed between the inner ring and the outer ring; and sealing materials provided on opening parts at both ends in the axial direction of the inner ring and the outer ring to seal the urea grease in the periphery of the rolling elements. The sealing material for sealing the grease at least includes a rubber formed body coming into contact with the grease. The rubber formed body is a formed body of vulcanizable fluororubber composition made of a copolymer containing tetrafluoroethylene, propylene, and a crosslinkable monomer consisting of unsaturated hydrocarbon having two to four carbon atoms, in which a part of hydrogen atoms is substituted with fluorine atoms, and this flywheel damper support structure uses the rolling bearing for the flywheel damper. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a rolling bearing that supports a flywheel damper of an automobile engine and a flywheel damper support structure that uses the rolling bearing.

With the widespread use of FF (front engine / front drive) vehicles for miniaturization and weight reduction, and further expansion of living space, automobiles are being forced to reduce their engine rooms. For this reason, electric parts for automobiles are further reduced in size and weight, and high performance and high output parts are increasingly required.
The flywheel damper attenuates fluctuations in drive system rotation by reducing the resonance frequency against torsional vibration caused by engine torque fluctuation when transmitting engine output to the driven system, reducing unpleasant noise and vibration. And used to transmit to the driven system.
A rolling bearing for a flywheel damper is a flywheel damper support structure that receives torsional vibration generated by engine output torque fluctuation at an engine-side mass, attenuates it, and transmits it to a transmission-side mass. Is a rolling bearing that supports the inner ring and the outer ring.
The flywheel damper that attenuates the torsional vibration generated by the engine output fluctuation and transmits the engine output to the driven system in this way is related to the transmission side. The mass and the engine side mass are supported by rolling bearings. The bearing is filled with grease containing urea as a thickener. The inner and outer rings are made of steel. The amount of retained austenite is 8% or less and the hardness is HRC60. The amount of grease to be filled is 40 to 50% of the bearing inner space, the base oil is synthetic oil, and the seal is made of fluoro rubber. In addition, there is a proposal that the grease has good heat resistance and has a long life with excellent fretting resistance (Patent Document 1).
Moreover, in the bearing which mutually supports the engine-side mass and the transmission-side mass of the flywheel damper, the bearing has contact seals on both sides, and each contact seal has a plurality of lip portions. Of these, the method of providing a slit for air venting at the innermost lip portion of the contact seal located on the opposite side of the engine-side mass prevents excessive increase in internal pressure due to the high temperature of the engine-side mass. First, there is known a method capable of avoiding problems caused by slipping of the clutch plate even if grease leakage occurs (Patent Document 2).
In addition to torsional vibrations and rotational irregularities that vary from 1000 rpm to 10000 rpm due to engine output fluctuations, flywheel dampers are extremely severe in high temperatures of 200 ° C or higher during high-speed operation in summer. High temperature reliability, grease sealability, and durability are required.
Urea grease is mainly used to lubricate rolling bearings. In addition, fluorine grease is used when the temperature conditions are more severe, but since fluorine grease is extremely expensive, the present inventors have identified a specific urea-based grease as a method for realizing the equivalent performance more economically. Japanese Patent Application No. 2002-100556 proposed a mixture of fluorine grease.

On the other hand, in applications where such temperature conditions are severe, heat resistance is also required for the seal material for rolling bearings. Conventionally, acrylic rubber has been used as an elastic body of the sealing material, but since acrylic rubber is not sufficiently heat resistant, cases using fluororubber are increasing.
Conventionally used fluororubbers include binary copolymers of vinylidene fluoride and hexafluoropropylene (VDF-HFP), and terpolymers of which tetrafluoroethylene is added (VDF-HFP-TFE). So-called FKM is common. When these fluororubbers are used in combination with fluorine grease, sufficient durability can be obtained.
However, a combination of fluororubber and urea-based grease has a problem that the fluororubber is cross-linked by the urea compound and hardens.
On the other hand, by using a terpolymer of vinylidene fluoride-tetrafluoroethylene-propylene or a tetrafluoroethylene-propylene binary copolymer as the fluororubber, a rolling bearing is used in combination with urea grease. There has been proposed a method for improving the durability (see Patent Document 3).

However, even when the above-described fluororubber is used, there is a problem that it is difficult to suppress deterioration with time of the fluororubber.
When the rubber elastic body used for the sealing material is cured, the sealing performance is deteriorated, so that grease leaks and the bearing life is shortened. 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.
JP 2000-55132 A JP 2000-179560 A JP 2001-66578 A

  The problem to be solved is that rolling bearings for flywheel dampers filled with grease containing a urea compound are used at high temperatures, and as a result, the seal material deteriorates, so that good sealability is maintained for a long time and excellent reliability is achieved. And the durability cannot be maintained, and there is no flywheel damper having excellent durability.

  A rolling bearing for a flywheel damper according to the present invention is a flywheel damper support structure in which torsional vibration generated by engine output torque fluctuation is received by an engine-side mass and attenuated and transmitted to a transmission-side mass. A rolling bearing for a flywheel damper that mutually supports a transmission-side mass, wherein 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, and grease around the rolling elements. The grease is a grease containing a urea compound, and the seal material for sealing the grease is at least the grease. A rubber molded body in contact with the tetrafluoroethylene, the rubber molded body, Molding of a vulcanizable fluororubber composition comprising a copolymer comprising 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 It is a body.

In addition, a crosslinking monomer composed of an unsaturated hydrocarbon having 2 to 4 carbon atoms in which a part of hydrogen atoms is substituted with a fluorine atom is trifluoroethylene, 3,3,3-trifluoropropene-1, It is at least one monomer selected from 2,3,3,3-pentafluoropropene, 1,1,3,3,3-pentafluoropropylene and 2,3,3,3-tetrafluoropropene It is characterized by.
In addition, the copolymer containing tetrafluoroethylene, propylene, and the above-mentioned crosslinking monomer contains vinylidene fluoride.
In addition, the grease containing the urea compound is a mixed grease of fluorine grease and urea grease.

  The flywheel damper support structure according to the present invention is a flywheel damper support structure in which torsional vibration generated by engine output torque fluctuation is received by the engine side mass and attenuated and transmitted to the transmission side mass. The rolling bearing that supports the side masses mutually is the above-described rolling bearing for a flywheel damper.

A rolling bearing for a flywheel damper according to the present invention comprises tetrafluoroethylene, propylene, and a crosslinking monomer comprising an unsaturated hydrocarbon having 2 to 4 carbon atoms in which a part of hydrogen atoms are substituted with fluorine atoms. Since the sealing material is formed from a vulcanizable fluoro rubber composition molded body comprising a co-polymer, the physical properties are hardly deteriorated even when immersed in grease containing a urea compound, and the leakage of grease is effectively prevented. be able to.
For this reason, it is subject to torsional vibrations and rotational irregularities that vary from 1000 rpm to 10000 rpm due to engine output fluctuations, and is used in extremely harsh environments of high temperatures of 200 ° C or higher during high-speed operation in summer. In the flywheel damper, the durability of the rolling bearing and the flywheel damper support structure that mutually support the engine-side mass and the transmission-side mass can be improved.

  The best mode for carrying out the present invention will be described with reference to FIGS. First, the flywheel damper support structure will be described. The upper half of FIG. 3 shows the AO cross section of FIG. 4, and the lower half of FIG. 3 shows the BO cross section of FIG. In this flywheel damper support structure, a flywheel 9 is divided into an engine-side mass 10 and a transmission-side mass 11, and a compression spring 12 and a damping mechanism 13 are provided between the flywheel 9 and the flyhole 9 itself has a damper structure. In the damper, both the masses 10 and 11 are mutually supported by the bearing 1. As the bearing 1, a rolling bearing is used so that damping is performed smoothly. Output torque from the engine enters from an engine-side mass 10 directly connected to a crankshaft (not shown), and is transmitted to a driven system via a compression spring 12, a damping mechanism 13, and a transmission-side mass 11. In this case, the compression spring 12 is bent and the damping mechanism 13 is actuated according to the magnitude of the output torque of the engine, and the torque fluctuation is absorbed by the compression spring 12 and the damping mechanism 13 in this state. 11 rotates with respect to the engine-side mass 10 with an attenuated rotational fluctuation amount. The damping mechanism 13 is formed by an oil chamber 13 a, and rotation transmission performed between the masses 10 and 11 via the compression spring 12 and the damping mechanism 13 is performed via the driven plate 14. The driven plate 14 is coupled to the transmission-side mass 11 by serrations 15 provided on the inner diameter portion. A stopper 16 is provided on the engine-side mass 10 so as to correspond to the protrusion 14 a provided on the outer diameter portion of the driven plate 14.

Rolling bearings for flywheel dampers that mutually support an engine-side mass 10 that is rotationally driven by engine output, and a transmission-side mass 11 that attenuates and transmits torsional vibration accompanying fluctuations in engine output torque to a driven system. An example 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. A retainer 5 that holds the plurality of rolling elements 4 and a sealing material 6 that is fixed to the outer ring 3 and the like are provided in the axial end openings 8a and 8b of the inner ring 2 and the outer ring 3, respectively. Grease 7 is sealed at least around the rolling element 4.

  The flywheel damper receives the torsional vibration generated by the output torque fluctuation of the engine by the engine side mass 10 and attenuates and transmits it to the transmission side mass 11. Therefore, the engine side mass 10 and the transmission side mass 11 are mutually connected. The rolling bearing 1 to be supported uses an inner ring 2 and an outer ring 3 that rotate together, and receives torsional vibration due to engine output fluctuation. In addition, the rolling bearing 1 is subjected to rotation unevenness that varies from 1000 rpm to 10000 rpm as the automobile travels, and is used in extremely severe environments of high temperatures of 200 ° C. or higher during high-speed operation in summer. Thus, the rolling bearing 1 is used in a wide temperature range and a wide rotation range from a low temperature to a high temperature.

The sealing material 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 material 6 made of a composite of a rubber molded body and a metal plate is shown in FIG. The sealing material 6 is obtained by fixing a fluororubber molded body 6b to a metal plate 6a such as a steel plate. As the fixing method, either mechanical fixing or chemical fixing may be used. 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 sealing material 6 can be mounted by (1) fixing one end 6c of the sealing material 6 to the outer ring 3, and forming the labyrinth gap along the V groove on the sealing surface of the inner ring 2 at the other end 6d. One end 6c of the material 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 sealing surface of the inner ring 2. (3) One end 6c of the sealing material 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 encapsulated grease 7 comes into contact with the rubber molded body 6b constituting the sealing material 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 fluororubber composition that can be used in the sealing material 6 incorporated in the rolling bearing 1 of the present invention is composed of tetrafluoroethylene, propylene, and a non-carbon having 2 to 4 carbon atoms in which some hydrogen atoms are substituted with fluorine atoms. A vulcanizable fluororubber composition comprising a copolymer comprising a crosslinking monomer comprising a saturated hydrocarbon.
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 copolymer constituting the fluororubber composition is 45 to 80% by weight, preferably 50 to 78% by weight, more preferably 65 to 78% by weight of tetrafluoroethylene based on the whole copolymer. Is 10 to 40% by weight, preferably 12 to 30% by weight, more preferably 15 to 25% by weight, and the crosslinking monomer is 0.1 to 15% by weight, preferably 2 to 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, the amount of each compound 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, acid acceptor 1-30 parts by weight, preferably 1-7 parts by weight, filler 5-100 parts by weight, and processing aid 0.1-20 parts by weight.

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 of 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 characteristics, it is preferable to perform secondary vulcanization after molding, and this is performed by sufficiently heating in an oven (for example, 200 ° C. for 24 hours).

A urea-based grease containing a urea compound is enclosed in the rolling bearing for the flywheel damper.
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、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 represents an aliphatic group, an alicyclic group, or an 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 little 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.
Preferred examples of the fluorine grease include polytetrafluoroethylene 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.

Urea-based greases and mixed greases used in the evaluation of each sealing material example, example, and comparative example are shown below.
(1) Urea-based grease Cluuba: Asonic HQ72-102 (Thickener: aliphatic diurea, base oil: aromatic polyester oil, kinematic viscosity at 40 ° C 100 mm ² / s) (2) Mixed grease In contrast, perfluoropolyether oil (DuPont brand name, Krytox 240AC) 67 wt%, fluororesin powder (DuPont brand name, Vidax) 33 wt% was added and stirred, then passed through a roll mill, A semi-solid fluorine grease which was “a grease using PTFE powder as a thickener and PFPE as a base oil” was obtained.
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 wt. After stirring, the reaction was continued at 100 to 120 ° C. for 30 minutes, and a urea compound (aliphatic diurea in which R ₁ and R ₃ are aliphatic groups and R ₂ is a diphenylmethane group) 12 % By weight 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 material 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 1. Each material used in Table 1 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

Seal material example 1 to seal material example 4, comparative seal material example 1 to comparative seal material example 8
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 specimen was embedded and immersed in the urea grease 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 2-4. In Tables 3 and 4, * indicates that measurement is impossible.

シール材例１〜シール材例４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。
比較シール材例２、３、６、７は、ウレア化合物を含有するグリースに浸漬された場合の物性劣化が著しい。また、比較シール材例１、４、５、８は 170 ℃の低温条件でのグリース浸漬や、高温条件で短時間（ 72 時間程度）の浸漬では物性変化は比較的小さいが、 200 ℃で長時間の浸漬では大きな物性低下がみられた。

Sealing material example 1 to sealing material example 4 had a slight deterioration even when immersed for a long time under a high temperature condition, and had excellent resistance to urea grease and mixed grease.
In Comparative Sealing Material Examples 2, 3, 6, and 7, physical property deterioration is significant when immersed in grease containing a urea compound. In Comparative Sealing Materials Examples 1, 4, 5, and 8, the change in physical properties is relatively small when grease is immersed under a low temperature condition of 170 ° C or when immersed for a short time (about 72 hours) under a high temperature condition. A significant decrease in physical properties was observed with time immersion.

Example 1
The unvulcanized rubber composition of Formulation Example 1 was molded into an iron 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 test bearing was prepared by enclosing a mixture of 38% fluorine grease and urea grease inside the bearing. The obtained rolling bearing was evaluated in a high temperature durability test. The results are shown in Table 5.
In the high temperature endurance test, the bearing was rotated at a radial load of 67 N, a thrust load of 67 N, a rotational 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.

Comparative Example 1 and Comparative Example 2
By using Formulation Example 2 and Formulation Example 3, the test bearings of Comparative Example 1 and Comparative Example 2 were produced in the same manner as Example 1. The same high temperature durability test as in Example 1 was performed, and the results are shown in Table 5.

実施例１では 1000 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、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。

In Example 1, the operation for 1000 hours or more was possible, and the seal after the test was also free from cracks.
On the other hand, in Comparative Example 1 and Comparative Example 2, image sticking occurred in a shorter time than in Example 1. Leakage of grease during operation seems to be the main cause of short life. In addition, many cracks were seen in the contact portion of the seal after the test of Comparative Example 2.

  Since the present invention has excellent urea-based grease resistance, it can be applied to flywheel damper rolling bearings and flywheel damper support structures used at high temperatures.

It is sectional drawing of the rolling bearing for flywheel dampers. It is sectional drawing of the rolling-bearing sealing material for flywheel dampers. It is a section (AOB section of Drawing 4) figure of a flywheel damper support structure. It is a fracture front view of a flywheel damper support structure.

Explanation of symbols

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

Claims (5)

  In a flywheel damper support structure that receives torsional vibration generated by engine output torque fluctuation by an engine-side mass and attenuates and transmits it to the transmission-side mass, the flywheel supports the engine-side mass and the transmission-side mass mutually. A rolling bearing for a damper, wherein 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, and a seal material for sealing grease around the rolling element. And the grease is a grease containing a urea compound, and the sealing material has a rubber molded body that contacts at least the grease, and the rubber molded body is tetra-coated. Fluoroethylene, propylene, and 2 carbon atoms with some hydrogen atoms replaced by fluorine atoms 4 of the rolling bearing for the flywheel damper which is a molded product of an unsaturated hydrocarbon comprising a copolymer containing a cross-linking monomer consisting of hydrogen vulcanizable fluororubber composition.   The crosslinking monomer is trifluoroethylene, 3,3,3-trifluoropropene-1, 1,2,3,3,3-pentafluoropropene, 1,1,3,3,3-pentafluoropropylene 2. The rolling bearing for a flywheel damper according to claim 1, which is at least one monomer selected from 2,3,3,3-tetrafluoropropene.   The rolling bearing for a flywheel damper according to claim 1 or 2, wherein the copolymer contains vinylidene fluoride.   4. The rolling bearing for a flywheel damper according to claim 1, wherein the grease containing the urea compound is a mixed grease of fluorine grease and urea grease.   In a flywheel damper support structure that receives torsional vibration generated by engine output torque fluctuation by an engine-side mass and attenuates and transmits it to the transmission-side mass, the flywheel supports the engine-side mass and the transmission-side mass mutually. The flywheel damper support structure, wherein the damper rolling bearing is the flywheel damper rolling bearing according to any one of claims 1 to 4.

Images