JP2003166553A - Rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a long-lived rolling bearing provided with a sealing device having excellent sealability even in adverse environment. <P>SOLUTION: In the rolling bearing provided with an outer ring having an outer ring raceway at the inner peripheral face, an inner ring having an inner ring raceway at the outer peripheral face, a plurality of rolling bodies set so as to freely roll between the outer ring raceway and the inner ring raceway, a cage holding the rolling bodies so as to freely roll with mutual certain distance in the circumferential direction, and a seal device covering an axial opening of a space in which the rolling bodies are disposed between the inner peripheral face of the outer ring and the outer peripheral face of the inner ring, the elastic members constituting the seal device is made of a crosslinkable rubber composition in which at least an organic peroxide is mixed with an acrylonitrile- butadiene rubber as the feature. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention
Prevents leakage and prevents external dust, water, muddy water, etc.
Equipped with a sealing device to prevent entry into the bearing
It relates to a rolling bearing. More specifically, for example, cars and iron
Rolling bearings and automobiles for wheels used to support road wheels
Frequent contact with water, like rolling bearings for electrical equipment
Rolling bearing used in such an environment. 2. Description of the Related Art For example, wheels for automobiles and railways are supported.
Rolling bearings for wheels are usually exposed to rainwater, wind and snow, and dust.
While used outdoors. Also rolling for car wheels
Bearings may be used in submerged water such as muddy water.
You. Furthermore, when the vehicle is washed, it is exposed to washing water. In a rolling bearing used in such an environment,
Conventionally, nitrile rubber is used as an elastic member of a sealing device.
A rubber composition in which additives are appropriately blended is used.
Such a general nitrile rubber composition is used for an elastic member.
The sealing device was relatively free of water and dust.
Sufficient sealing performance in a so-called clean environment
Having. However, when exposed to large amounts of water,
Performance is insufficient, especially when submerged
As a result, the sealing performance deteriorates and water
In both cases, dust and the like easily enter. As a result,
Lubricants such as stainless steel deteriorate, and rolling bearings
It becomes difficult to maintain the barrel performance, and there is a possibility that it will be damaged early
come. In order to deal with such a problem, the sealing device
Increasing tension is also used to improve sealing performance
However, the sealing torque increases and the fuel efficiency of the vehicle decreases.
Not only causes the lip of the elastic member to wear
Is likely to reduce the sealing performance,
May deteriorate the grease and shorten the bearing life.
There is also. [0005] As described above, as described above,
Equipped with a sealing device using the rubber composition of
Ball bearings may be exposed to large amounts of water,
If used in
You. [0006] Accordingly, the present invention is directed to such a poor environment.
Even with a sealing device with good sealing properties, long life
An object of the present invention is to provide a rolling bearing. [0007] In order to achieve the above object,
For example, the present invention provides an outer race having an outer raceway on an inner peripheral surface,
An inner race having an inner raceway on a peripheral surface, the outer raceway and the inner raceway;
A plurality of rolling elements provided to be able to roll between wheel raceways
And the rolling elements are spaced from each other in the circumferential direction.
A retainer that is rotatably held in a state, and an inner peripheral surface of the outer ring
Between the outer peripheral surface of the inner ring and the space in which the rolling elements are provided.
Rolling bearings with a sealing device to close the axial opening
In this case, the elastic member constituting the sealing device is an acrylic member.
Lonitrile butadiene rubber with at least organic peroxide
Characterized by being composed of a compounded crosslinkable rubber composition
To provide rolling bearings. [0008] The rolling bearing of the present invention will be described below.
This will be described in detail with reference to the drawings. In the present invention, the configuration itself of the rolling bearing is
Although not particularly limited, for example, as shown in FIG.
Of rolling bearings for vehicles that support such automobile wheels
can do. In the illustrated rolling bearing O,
The outer ring equivalent member 1 which is a fixed ring is formed on the outer peripheral surface thereof.
It is supported and fixed to a suspension device (not shown) by the mounting portion 2.
You. Therefore, the outer ring equivalent member 1 does not rotate during use.
No. Inside such an outer ring equivalent member 1 is a rotating wheel.
The wheel equivalent member 3 is provided concentrically with the outer ring equivalent member 1 and
The inner ring-equivalent member 3 rotates during use. This inner ring equivalent part
The member 3 includes a hub 4 and an inner ring 5. Hub 4 of these
A spline groove 6 is provided on the inner peripheral surface of the
The outer edge in the width direction at the time of cutting
Mounting flanges 7 are formed on the surfaces. car
When assembling to both, the spline groove 6 has a constant speed joy
A drive shaft that is driven to rotate via a
A wheel is fixed to the attached flange 7. The outer peripheral member 1 has a double row
The ring raceways 8, 8 are formed by the outer peripheral surface of the intermediate portion of the hub 4 and the inner race.
Inner ring tracks 9 and 9 are formed on the outer peripheral surface of
ing. Each of these outer raceways 8, 8 and the inner raceway
Rolling elements 10 and 10 are provided between the outer ring phases
The inner ring-equivalent member 3 can be freely rotated inside the member 1
I have. Further, the rolling elements 10 and 10 are rotatably held.
For this purpose, retainers 11, 11 are provided. In addition, the illustration
In the example, balls are used as the rolling elements 10 and 10,
In the case of a hub unit for a large vehicle, the rolling element
In some cases, a tapered roller is used. Furthermore, the outer race
Between the outer end of the member 1 and the outer peripheral surface of the intermediate portion of the hub 4
Is provided with sealing devices 12a and 12b,
Between the inner peripheral surface of the member 1 and the outer peripheral surface of the inner ring equivalent member 3
Outside of the space 13 where the rolling elements 10 and 10 are installed.
The end opening is closed. The sealing device 12a is shown enlarged in FIG.
So that the metal core 105, the slinger 106, and the elastic portion
And material 107. The core 105 of these is
Punching process such as press working on metal plate such as low carbon steel plate
In addition, they are integrally formed by plastic working. This
Is equivalent to the outer ring constituting the rolling bearing O.
Outer diameter side cylindrical portion 10 which can be fitted and fixed on the inner peripheral surface of the end of member 1
9 and the inner edge in the axial direction of the outer diameter side cylindrical portion 109 (see FIG. 2).
Inner ring part 1 bent inward in the diameter direction from the left edge)
10 and is formed in an annular shape with a substantially L-shaped cross section.
You. Further, the slinger 106 is made of a stainless steel plate or the like.
For metal plates with excellent corrosion resistance,
Punched and plastically processed to form
Have been. Such a slinger 106 is provided with the above-mentioned rolling bearing.
O which can be externally fitted and fixed to the outer peripheral surface of the outer end of the inner ring 5 constituting O
Radial-side cylindrical portion 112 and axial direction of this radial-side cylindrical portion 112
Bent diametrically outward from the outer edge (right edge in FIG. 2)
With an outer annular portion 113, which is annular in an L-shaped cross section.
Is formed. Further, the elastic member 107 has an outer side and a middle side.
The inner and inner three sealing lips 114, 115, 116
And the base end thereof is fixedly connected to the cored bar 105.
I have. Then, the outermost seal lip 1 located on the outermost side
The outer edge of the outer ring forming the slinger 106
Slide the inner surface of the part 113 into the other two seal lips.
Intermediate seal lip 115 and inner seal lip 1
16 with the inner edge of the slinger 106
By sliding the outer peripheral surface of the cylindrical portion 112, the sealing group
While preventing leakage of the lease,
Prevents water and muddy water from entering the bearing. The sealing device 12b is shown enlarged in FIG.
Core bars 216 each formed in an annular shape so that
And an elastic member 217. Core 2 of these
An outer end 16 of the outer ring equivalent member 1 is made of a metal plate.
It is fixed inside the part. The elastic member 217
Are the outer diameter side, the inner diameter side, and two side seal lips 21
8, 219 and one radial seal lip 220
And is fixed to the core metal 216 by bonding or the like.
You. Then, the two side seal lips 218, 2
19 toward the leading edge (left edge in FIG. 3).
By tilting it in the direction toward
The function of preventing foreign matter from entering the space 13 is ensured. Ma
In addition, the radial seal lip 220 is attached to the leading edge (FIG. 3).
Toward the lower side of the space 13 (the lower right of FIG. 3).
Side) to prevent grease leakage.
The leak prevention function is secured. More specifically, the sealing device 12b
Is a core metal 216 and an elastic portion, each of which is formed in a ring shape.
217. Core of sealing device 12b
The gold 216 is formed by pressing a metal plate such as a low carbon steel plate by pressing.
By performing punching and plastic forming,
Have been. This core metal 216 constitutes the rolling bearing O.
An outer diameter side circle which can be fitted and fixed on the inner peripheral surface of the end of the outer ring equivalent member 1.
The cylindrical portion 222 and the outer edge of the outer diameter side cylindrical portion 222 (FIG. 3)
Support plate 2 bent inward in the diametric direction from the left edge of the
23. The outer cylindrical portion 222 of the inner
The large-diameter portion 224 near the end (rightward in FIG. 3) and the elastic member 21
7, the outside of the support plate portion 223 constituting the metal core 216
This elastic member covers the entire side surface (the left side surface in FIG. 3).
217 is continuous from the fitting cylinder 222.
Outer peripheral surface of inclined portion 227 and inner periphery of open end of outer ring equivalent member 1
It is sandwiched between surfaces. And with this configuration,
The fitting portion between the core metal 216 and the outer ring equivalent member 1 is sealed.
You. The outer diameter of the large diameter portion 224 in a free state.
Is slightly larger than the inner diameter of the outer end opening of the outer ring equivalent member 1.
The large-diameter portion 224 is an outer ring equivalent portion.
The inner end of the material 1 can be fixed inside by an interference fit.
ing. The support plate portion 223 has a substantially S-shaped cross section.
It has a shape, and the more it goes inward in the diametric direction (downward in FIG.
Direction approaching the rolling elements 10 and 10 installed in the space 13 (FIG.
3 to the right). On the other hand, together with the core 216, the sealing device
The elastic member 217 constituting the arrangement 12b is
Insert molded into and fixed by bonding etc.
ing. The outer peripheral edge of such an elastic member 217 is inclined as described above.
The outer peripheral surface of the portion 227 is covered. Also, such an elastic part
Part that covers the outer peripheral surface of the inclined part 227 with a part of the material 217
In the free state, the outer diameter of the outer ring equivalent member 1 is
It is set slightly larger than the inner diameter of the mouth,
In a state where the portion 224 is internally fitted and fixed to the outer end opening,
A part of the elastic member 217 covers the outer peripheral surface of the inclined portion 227.
Is the outer peripheral surface of the inclined portion 227 and the outer end opening.
It is elastically pressed between the inner peripheral surface of the mouth and
To ensure good security. Further, the base 226 of the elastic member 217
The outer surface (the left side surface in FIG. 3) of the support plate portion 223 is
It is completely covered all around. In addition, the base 226
Outer side, inner side, two sides
Seal lips 218, 219 and one radial seal
A lip 220 is formed, and two side seams are formed.
Rip 218, 219 at the leading edge (left edge in FIG. 3)
As it moves, it tilts in the direction toward diametrically outward (upward in FIG. 3).
By tilting, the function to prevent foreign matter from entering the space 13
Have secured. The radial seal lip 220
Of the space 13 toward the leading edge (lower right edge in FIG. 3).
By inclining in the direction toward the inside (right side in FIG. 3)
The grease leakage prevention function is secured. Further, as a rolling bearing, as shown in FIG.
Illustrates a rolling bearing for a vehicle that supports wheels of a railway vehicle
You can also. FIG. 4 shows the axle part 400,
Wheels (not shown) are attached to the right side (vehicle side W ') in the figure.
A rotating shaft 401 and a bearing 40 supporting the shaft 401
2 is provided. And the outer ring 403 of the bearing 402
Configuration to be fixed to the axle housing etc. of a railway vehicle (not shown)
It is. The bearing 402 has a double-row tapered roller 404.
a, 404b are arranged outward, so-called sealed double-row circle
The axle housing is referred to as a tapered roller bearing.
Outer ring 403 fixed to the
The wheels 405a and 405b and the inner ring spacer 406 are provided.
You. The tapered rollers 404a and 404b are provided in the cage 40.
4c. This bearing 402 is connected to the shaft 401
Fixed at a predetermined position on the journal 401a that receives the load
In order to do so, the wheel side W ′ of the journal portion 401a is thick.
A shaft neck 401b having an outer diameter is provided and abuts on the shaft neck 401b.
The inner ring 4 via the rear lid 407 and the oil drain sleeve 408
05b is in contact with the wheel side end. Also journal
The free end side F 'of the portion 401a is the free end side F' of the shaft 401.
Front lid 410 fixed to end 401c of
Is attached to the holding portion 410a of the front lid 410.
Of the inner ring 405a via the oil draining sleeve 411 on the side F '.
The free end is in contact. And bolt 409
By tightening to a predetermined torque, the bearing 402
It is sandwiched and fixed between the neck 401b and the front lid 410.
The member indicated by reference numeral 412 has the bolt 409 loosened.
This is a rotation stopper that prevents Also, at 413
The members shown indicate that water or foreign matter is
In the bearing 402, and
Sealing device to prevent leakage of lubricant such as grease
And both the wheel side W ′ and the free end side F ′ of the bearing 402
Are provided with a similar configuration. The sealing device 413 is shown enlarged in FIG.
(However, the vehicle side W ′ is shown)
A seal case 413a fitted and fixed to both ends;
Oil cut sleeve attached to the end of the case 413a
Oil seal 413 sealingly in contact with the outer peripheral sliding surface of 408
b. The oil seal 413b is a seal case
The spring cover 413c and the spring cover 413c
Reinforcing ring 413d fitted on the inner diameter side of the fitting is fitted and fixed
Water and foreign matter that intrudes in the direction of arrow A401 from the outside
The dust lip 413e of the elastic member 410 and the main lid
413f and the inside of the bearing 402
To prevent leakage of grease and other lubricants enclosed in
You. The member denoted by reference numeral 414 is the main lip 4
13f is a spring ring for urging 13f. Also, Spring
The outer cover of the oil draining sleeve 408 is
There is a radial part that extends to near the moving surface,
The inside of the device 413 is tapered roller side J 'and oil seal side
M ′. And split like this
As a result, polishing of the lip generated on the oil seal side M '
When the wear powder is prevented from entering the tapered roller side J '
The metal abrasion powder generated on the tapered roller side J 'is oil
Intrusion into the seal side M 'is prevented. In the rolling bearing of the present invention, the system shown in FIG.
Elastic member 107 of the sealing device 12a, the seal shown in FIG.
Elastic member 217 of device 12b, sealing device shown in FIG.
The elastic member 410 of FIG. 413 is formed of the following rubber composition.
To achieve. Acrylonit which is a rubber raw material for a rubber composition
Rilbutadiene rubber is composed of butadiene and acrylonitrile
Is widely known as an oil-resistant rubber copolymerized with
ing. In the present invention, this acrylonitrile pig
Hydrogenated acrylonitrile by hydrogenation as diene rubber
Carboxyl group introduced into rubutadiene rubber or molecule
Modification of carboxylated acrylonitrile butadiene rubber
Acrylonitrile butadiene rubber and isoprene
Acronitrile butadiene isoprene rubber copolymerized
Etc. can be used. Acrylonitrile butadiene rubber
Depends on the content of acrylonitrile,
Nitrile, medium nitrile, medium-high nitrile, high nitrile, pole
There is high nitrile, but heat resistance, oil resistance, abrasion resistance,
Considering the leap property, lip following property, etc., medium nitrile,
Medium and high nitriles and high nitriles are preferred.
The content of rilonitrile is 20-40%. More suitable
Contains 25 to 36% acrylonitrile
And these properties are expressed in a well-balanced manner. The rubber composition has an organic peroxide as a crosslinking agent.
Things are added indispensably. The types of organic peroxides are limited
Although not necessarily, for example, t-butyl hydroperoxy
Sid, 2,5-dimethylhexane-2,5-dihydrope
Oxide, di-t-butyl peroxide, dicumylpe
Peroxide, t-butylcumyl peroxide, 2,5-
Dimethyl-2,5-di (t-butylperoxy) hexa
2,5-dimethyl-2,5-di (t-butylperoxide)
Xy) hexyne-3,1,3-bis (t-butylperoxide)
1. (xyisopropyl) benzene, 2,5-dimethyl-2.
5-di (benzoylperoxy) hexane, 1,1-bi
Tert-butylperoxy-3,3,5-trimethyl
Siloxane, benzoyl peroxide and the like.
It is appropriately selected according to the molding method, molding temperature, and the like. In addition,
The amount of peroxide is acrylonitrile butadiene
The amount is preferably 1 to 10 parts by weight based on 100 parts by weight of the rubber. Further, a sulfur-based crosslinking agent (vulcanized crosslinking agent) may be used.
You may use together. The type is not particularly limited, but powder
Various sulfur such as sulfur, sulfur flower, precipitated sulfur, highly dispersible sulfur,
Sulfur compounds that can release sulfur such as morpholine disulfide
Objects and the like. Of these, dispersibility, ease of handling
Sulfur and morpholine disulfide in terms of heat and heat resistance
It is preferred to use When a sulfur-based crosslinking agent is used in combination,
Anidine, aldehyde-ammonia, thiazole
System, sulfenamide system, thiourea system, thiuram system, di
As a vulcanization accelerator such as thiocarbamate and xanthate
Must be used. Of these, if a small amount of sulfur is blended
Thiuram tetramethylthiuram disulphide
And sulfenamide N-cyclohexyl-2-
Benzothiazyl sulfenamide and thiazole-based
It can be used in combination with 2-mercaptobenzothiazole
preferable. Further, as a vulcanization accelerator, zinc oxide and the like can be used.
Metal oxides, metal carbonates, metal hydroxides, stearic acid
Fatty acids and their derivatives, amines, etc.
Can be. Carboxyl-modified acrylo as raw rubber
When nitrile butadiene rubber is used,
Zinc peroxide and stearin
It is preferable to use in combination with an acid. Peroxide
At the temperature at the time of kneading the rubber composition, lead is
Is present in the rubber composition and produces zinc oxide during vulcanization molding.
Premature vulcanization may occur during kneading and storage.
Absent. Further, a crosslinking aid (coagent) is used
You can also. Examples of crosslinking aids include tetrahydro
Furfuryl methacrylate, ethylene dimethacrylate
G, 1,3-butylene methacrylate, 1,4-methyl
Range methacrylate, 1,6-hexanediol dime
Tacrylate, polyethylene glycol dimethacrylate
G, 1,4-butanediol diacrylate, 1,6-
Hexanediol diacrylate, 2,2'-bis (4
-Methacryloxydiethoxyphenyl) propane, 2,
2'-bis (4-acryloxydiethoxyphenyl) p
Lopan, trimethylolpropane triacrylate,
Limethylolpropane trimethacrylate, pentaerythri
Thritol triacrylate, 3-chloro-2-hydro
Xypropyl methacrylate, oligoester acryle
Metal, aluminum (meth) acrylate, zinc
TA) Acrylate, magnesium (meth) acrylate
G, calcium (meth) acrylate, triallyl iso
Cyanurate, triallyl cyanurate, triallylto
Remelitate, diallyl phthalate, diallyl chlorene
Date, divinylbenzene, 2-vinylpyridine, N,
N'-methylenebisacrylamide, p-quinone dioxo
Shim, p, p'-dibenzoylquinone dioxime, 1,
2-polybutadiene, metal methacrylate and the like.
You. The amount of these crosslinking aids is acrylonitrile
1 to 10 parts by weight per 100 parts by weight of diene rubber is preferred.
New Further, a reinforcing filler is added to the rubber composition.
Is preferably added. This reinforcing filler
Carbon black and inorganic white fillers are preferred.
The type of carbon black is not particularly limited, for example,
SAF (Super Abrasion Furnace black), ISAF (Int
ermediate Super Abrasion Furnace black), HAF (Hi
gh Abrasion Furnace black), MAF (Medium Abrasion
Furnace black), FEF (Fast Extruding Furnace bla
ck), GPF (General Purpose Furnace black), SRF
(Simi-Reinforcing Furnace black), FT (Fine Therma
l Furnace black), MT (Medium Thermal Furnace blac
k) and the like, among which reinforcing properties and moldability
HAF, FEF, GPF, SRF excellent in
Particularly, FEF, GRF, and SRF are preferable. These cars
Bon black may be used in combination of two or more.
No. The white filler is not particularly limited.
For example, hydrous silica, clay, talc, calcium carbonate, silica
Algae soil, wollastonite and the like can be exemplified. Ma
These white fillers are used in combination of two or more.
It may be. The amount of the reinforcing filler is not particularly limited.
Although it is not something that uses carbon black alone,
If acrylonitrile butadiene rubber 100 parts by weight
It is preferably 15 to 120 parts by weight. Less than 15 parts by weight
If it is, sufficient reinforcement is not expressed and the wear resistance is also satisfied
No result. Conversely, add more than 120 parts by weight
No further improvement in reinforcement and wear resistance is observed
In addition, the moldability becomes extremely low, making production difficult.
In addition, the hardness is too high, the elongation is low,
The inherent rubber elasticity decreases. In addition, white
When using the filler alone, use acrylonitrile butadiene
20 to 180 parts by weight for 100 parts by weight of rubber
No. If it is less than 20 parts by weight, sufficient reinforcing properties are exhibited.
And the wear resistance is not satisfactory. Conversely, 180
Even if it is added in excess, the reinforcement and abrasion resistance are further improved.
Not only the above is not recognized, but the moldability is extremely reduced
Manufacturing becomes difficult, and the hardness is too high
Elongation decreases, and the inherent rubber elasticity decreases.
U. Also, use carbon black and white filler together.
When adding carbon black, 10 to 90 weight
Parts, 10 to 150 parts by weight of a white filler, and 2
The amount is preferably 0 to 240 parts by weight. The total amount added
If the amount is less than 20 parts by weight, sufficient reinforcing properties are not exhibited, and
In addition, even if added in excess of 240 parts by weight, reinforcement and wear resistance
Not only is there no further improvement in formability, but also moldability
Is extremely low, making it difficult to manufacture.
Elongation is too high and elongation is low, and the inherent rubber elasticity
Will drop. In addition, the rubber composition may contain a wear modifier or a friction modifier.
By adding a lubricant (lubricant), lubricity of the elastic member
Can be improved. The wear improver has a melting point of 40 to 140.
° C wax (low melting point fat) can be used. Specifically
Are paraffin wax or microphones in the above melting point range.
Petroleum waxes, such as locrystallin wax,
Polyethylene wax, montan wax, carnauba
Box, ester wax, stearoamide, oxy
Stearoamide, erucinamide, laurylamide, pa
Lumitylamide, behenamide, methylolamide, d
Tylene bis oleyl amide, stearyl oleyl amide
Etc., of which polyethylene wax is preferred.
No. The amount of these waxes added is acrylonitrile
3 to 30 parts by weight per 100 parts by weight of butadiene rubber
preferable. If the amount added is less than 3 parts by weight, sufficient lubricity is imparted.
If it cannot be given and exceeds 30 parts by weight, sufficient tensile strength
Not only the degree and elongation are not obtained, but also the rubber elasticity decreases,
Extremely strong adhesion between the core metal and the elastic member of the sealing device
To decline. As the friction modifier, mineral oil, ether type
Oil, silicone oil, poly α-olefin oil
Oil, fluorine oil, fluorine surfactant, etc.
Among them, silicone oils are preferred. Silicone-based
The type of il is not particularly limited.
Part of the methyl group or the molecular end of the sun is an amino group,
Alkyl group, epoxy group, polyether group,
Modified silicone oils substituted with stells etc. are preferred
Phase with acrylonitrile butadiene rubber
The solubility increases. In addition, these functional groups are acrylonitrile
Reacts with or adsorbs to the main chain of rilbutadiene rubber, and is elastic
While preventing blooming on the surface of the member at once,
Bloom gradually and permanently, maintaining lubrication for a long time
Is done. The viscosity of silicone oil is limited.
But not for acrylonitrile butadiene rubber
2 to 10 in kinematic viscosity at 25 ° C.
000mm ^Two / S range is preferred. Further, since the friction modifier is in a liquid state, it has elasticity.
Bloom easily on the surface of the member, effective from a small amount
You. Therefore, the addition amount of the friction modifier is acrylonitrile
1 to 30 parts by weight per 100 parts by weight of butadiene rubber
preferable. Sufficient lubricity with less than 1 part by weight of friction modifier
Can not be applied and if it exceeds 30 parts by weight,
In addition to poor dispersion of additives, the sealing device
Adhesion between the resulting core metal and the elastic member is extremely reduced. Further, the rubber composition includes a conventionally known aging agent.
Antioxidants, reinforcing agents, plasticizers, coupling agents, pigments, dyes
Compounding agents such as additives, mold release agents, processing aids, and conductivity-imparting agents
Can be added and blended as appropriate. Some of them are shown below.
You. Antioxidants for preventing oxidative deterioration include:
Amine-ketone condensation products, aromatic secondary amines,
Nophenol derivatives, bis or polyphenol derivatives,
Hydroquinone derivatives, sulfur-based anti-aging agents, phosphorus-based anti-aging
And the like. Of these, amine-ketone condensation products
2,2,4-trimethyl-1,2-dihydroxy compound
Noline polymer, condensation reaction between diphenylamine and acetone
N, N'-di-β-naph of aromatic secondary amine
Tyl-p-phenylenediamine, 4,4'-bis-
(Α, α-dimethylbenzyl) diphenylamine, N-
Phenyl-N '-(3-methacryloyloxy-2-h
(Droxypropyl) -p-phenylenediamine and the like are preferred.
New Further, heat decomposition is prevented to improve heat resistance.
Therefore, a secondary antioxidant is used together with the above antioxidant.
Is more preferable. As secondary anti-aging agents, sulfuric acid
Yellow 2-mercaptobenzimidazole, 2-merca
Ptomethylbenzimidazole and their zinc salts
No. In addition, the turtles
Melting point of 55 to 7
Acrylonitrile butadiene wax at about 0 ° C
0.5 to 2 parts by weight per 100 parts by weight
May be. Further, it is necessary to improve the moldability.
In such a case, a plasticizer is appropriately added as a processing aid. Was
However, if there is no particular problem in molding, it is not necessary to add
Good. When adding acrylonitrile butadiene
3 to 20 parts by weight for 100 parts by weight
When added above, the rubber composition softens,
Bleed out without being mixed into
The adhesiveness between the core metal and the elastic member is extremely reduced. Plasticizer
Examples of phthalic acid such as dioctyl phthalate
Diester, polyester plasticizer, polyether
Plasticizer, polyetherester plasticizer, liquid nitrile
And the like. By the way, electricity is supplied between the axle and the wheel bearing.
If there is no mechanism to generate electricity, static electricity generated while driving the car
Is left on the vehicle and radio noise is heard when the vehicle starts running
In some cases, a problem that causes such a problem may occur. Dealing with this
For this purpose, the elastic member of the seal device for rolling bearings for wheels must be
It is considered to make the bearing conductive and to energize the bearing and axle.
You. When the elastic member is made conductive, its resistance value is particularly high.
The volume resistivity is not limited to 10 ^Five Ωcm or less
If it is less than this, the radio noise is sufficiently suppressed.
It is possible to control. How to make an elastic member conductive
Although not particularly limited, conductive powder or conductive powder may be contained in the rubber composition.
Electrically conductive fibers can be added. For example, conductive powder
As brass, aluminum alloy, copper, silver, nickel
Metal powder such as steel, steel and stainless steel, graphite, conductive
Carbon black, tin oxide doped with antimony
Conductive tin oxide and zinc oxide doped with aluminum
Conductivity of tin doped electroconductive zinc oxide and indium oxide
Powdered conductive material such as conductive indium oxide
Or conductive coating on powder of insulating material such as mica
And others. In addition, conductive fibers include fibers.
Fiber, metal fiber (brass, aluminum alloy, copper,
Fibers made of silver, nickel, steel, stainless steel, etc.),
Non-conductive fibers with conductive coating
Can be used. In particular, highly developed graphite structures
Conductive carbon black has poor mechanical properties and
It is preferable because the influence on the property is small. Conductive carbon bra
Acetylene black and Ketjen
Black has better conductivity because of its small amount,
It is preferred. Acetylene black and Ketche
The amount of added black is not particularly limited.
1 to 20 parts by weight based on 100 parts by weight of tolylbutadiene rubber
Parts are preferred. If it is less than 1 part by weight, sufficient conductivity (1
0 ^Five Ω · cm or less).
The noise is not satisfactory. Conversely, 20 parts by weight
Even if it is added beyond the limit, workability will be extremely reduced and
Not only is it difficult, but the hardness is too high and the elongation is low
As a result, the inherent rubber elasticity decreases. In terms of physical properties, the hardness of the elastic member is
The effect is affected by the amount of reinforcing filler, wear modifier, etc.
But for wheels of automobiles and railway cars, or steel
Density when applied to rolling bearing seals for rolling mills
The spring described in JIS K6301 because of its sealing property and followability
In the hardness A scale, a range of 50 to 90 is preferable. Previous
If the hardness is less than 50, the frictional resistance of the sealing device
As the size increases, the wear resistance decreases. In addition, the hard
If it exceeds 90, the sealing force will increase
Not only the rotational torque becomes excessive, but also
As the rubber elasticity decreases, sealing of the lip of the sealing device
Exposure to dusty environments and muddy water
Life in rolling bearings when used in situations
There is a risk. The above rubber composition is used as an elastic member of a sealing device.
Although there is no particular limitation on the method for performing the
What is necessary is just to heat the product while pressing it in the mold.
Known rubber molding such as shape, transfer molding, and injection molding
It can be manufactured by a method. For example, compression molding
In this case, a core metal (seal
Insert the core of the uncured rubber composition)
And apply for 30 seconds to 30 minutes at 120 to 200 ° C.
It can be manufactured by pressure vulcanization. Also need
Depending on the post-crosslinking at 120-200 ° C for 10 minutes to 10 hours
May be. EXAMPLES The present invention will be further described below with reference to examples.
You. However, the present invention is not limited at all by the examples.
There is no. (Preparation of test sample) Materials shown in Tables 1 and 2
Materials excluding organic peroxides, vulcanizing agents and vulcanization accelerators
Into the press kneader in the amount indicated respectively,
Kneading was performed at a constant temperature of 80 ° C. Then, the resulting blend
Organic peroxide, vulcanizing agent, vulcanization accelerator
Add in the amount indicated, and roll 6 inches (rotation speed 20r
(rpm, 32 rpm) at a set temperature of 50 ° C.
To produce an unvulcanized rubber sheet having a thickness of 2.2 mm.
Was. Then, the sealing device is previously cleaned in the mold.
It is made of cold-rolled steel sheet that has been coated with an adhesive and baked.
Insert the metal core 105 having the above-mentioned shape into the unvulcanized rubber sheet.
And place it at 180 ° C for 10 minutes at a pressure of 30 kgf / c.
m ^Two And vulcanization molding is performed, and the sealing device shown in FIG.
A test sealing device similar to the device 12a was manufactured. In addition, organic
In the example using peroxide as a crosslinking agent, the mold was removed from the mold.
And post-vulcanize in an oven at 150 ° C for 2 hours.
Was. The thickness of the hot press heated to 180 ° C.
Attach a 2mm sheet molding die, and
Place the vulcanized rubber sheet, pressure 50kgf / cm for 15 minutes
^Two Heat and pressurize at 150mm length, 150mm width, thickness
A 2 mm-thick vulcanized rubber sheet was obtained. In addition, organic peroxide
In the example used for the crosslinking agent, the mold was taken out of the mold and
Post-vulcanization was performed at 150 ° C. for 3 hours in a vacuum oven. [Table 1] [Table 2] The used raw rubber, organic peroxide,
Fillers, additives and the like are as follows. 1) Raw rubber A: Middle and high nitrile rubber (manufactured by Zeon Corporation)
"Nipol DN3350", acrylonitrile simple substance
2) Raw rubber B: medium nitrile rubber (“N” manufactured by Zeon Corporation)
ipol DN2850 ”, an acrylonitrile monomer
3) Raw rubber C: high nitrile rubber (“JSR” manufactured by JSR Corporation)
N220S ”, ratio of acrylonitrile monomer: 41
%) 4) Raw rubber D: carboxylated medium-high nitrile rubber (JP
Zeon “Nipol DN631”, Acryloni
5) Carbon black A: HAF grade carbon black
("Diablack H" manufactured by Mitsubishi Chemical Corporation) 6) Carbon black B: FEF grade carbon black
(Asahi 60 "Asahi 60") 7) Carbon black C: GPF grade carbon black
("Seast V" manufactured by Tokai Carbon Co., Ltd.) 8) Carbon black D: SRF grade carbon black
("Seast S" manufactured by Tokai Carbon Co., Ltd.) 9) Silica: hydrous silica (Nippon Silica Industries, Nip)
Seal AQ) 10) Clay: calcined clay (Engelhard Min)
11) Vulcanizing agent: highly dispersible sulfur (Tulumi Chemical Co., Ltd. “Sul”
fax PMC ”) 12) Vulcanization accelerator A: tetramethylthiuram disulfide
(“Noxeller TT” manufactured by Ouchi Shinko Chemical Co., Ltd.) 13) Vulcanization accelerator B: N-cyclohexyl-2-benzothi
Azil sulfenamide (Ouchi Shinko Chemical Co., Ltd.
14) Vulcanization accelerator A: stearic acid (Lun manufactured by Kao Corporation)
ac S-35 ") 15) Vulcanization accelerator B: zinc oxide
Method No. 1)) 16) Vulcanization Accelerator C: Zinc Peroxide Masterbatch (Japan
17) Activator: diethylene glycol (manufactured by Nippon Shokubai Co., Ltd.) 18) Organic peroxide A: 1,3-bis (t-butylperoxide)
Xyloxy) benzene (Peroxy manufactured by NOF Corporation)
Mon F-40 ”, active ingredient: 40%)) 19) Organic peroxide B: dicumyl peroxide
(Kayakmill D-40K, manufactured by Zo Corporation, active ingredient: 40%)
"Adeka Sizer PN-150") 21) Antioxidant A: 4,4-bis (α, α-dimethyl
Diphenylamine (Ouchi Shinko Chemical Co., Ltd.
Crack CD ") 22) Antioxidant B: 2-mercaptobenzimidazole
Zinc salt (Ouchi Shinko Chemical Co., Ltd. “Nocrack MB
Z ") 23) Antioxidant C: Special wax (Ouchi Shinko Chemical Co., Ltd.)
24) Coupling agent A: γ-mercaptopropyl trime
Toxisilane (“KBM803” manufactured by Shin-Etsu Silicone Co., Ltd.) 24) Coupling agent B: vinyl tris (β-methoxy)
Ethoxy) silane (“A-172” manufactured by Nippon Unicar) 25) Co-crosslinking agent: triallyl isocyanurate (Nippon Kasei)
(TAIC M-60, active ingredient: 60%)) (Sealability test) Seal rotation test shown in FIG.
Using a machine 100, the state where the sealing device is submerged in muddy water
Assumed and implemented. Note that the illustrated seal rotation tester 1
00 attaches a slinger 106 (see FIG. 2) to the shaft 101
The sealing device 12a (inner diameter 60 mm)
A predetermined rotation speed while immersing in muddy water 102 stored in the section
It is configured to rotate in degrees. In addition, of muddy water 102
An earth leakage sensor 103 is installed on the opposite side of the storage
It is configured to detect when muddy water 102 leaks
I have. The test conditions are as follows, and water leakage is detected
And measured results are shown in Tables 3 and 4
Indicated as hours.・ Rotation speed: 1000 rpm ・ Axial eccentricity: 0.5 mm TIR ・ Muddy water composition: JIS Class 8 dust 20% ・ Grease: urea compound, mineral oil ・ Amount of grease applied: Outer seal lip and middle seal lip
0.3g between middle seal lip and inner seal lip
(Measurement of physical properties in normal state) Hardness test: Vulcanized rubber sheet was JIS dumbbell shape No. 3
Punched into the shape of a test specimen
Hardness (spring hardness A scale
Was measured. The measurement results are shown in Tables 3 and 4.・ Tensile test: JIS dumbbell-shaped No. 3 test piece
, A universal testing machine Autograph AG-1 manufactured by Shimadzu Corporation
Tensile test based on JIS K6301 by 0KNG
The tensile strength at break and elongation were measured. Measurement results
The results are shown in Tables 3 and 4. [Table 3] [Table 4] As shown in Tables 3 and 4, according to the present invention,
Organic peroxide to acrylonitrile butadiene rubber
Example using an elastic member made of a compounded rubber composition
All have a long muddy water endurance time,
Effect was confirmed. As described above, the rolling shaft of the present invention is
The receiver uses acrylonitrile for the elastic member that constitutes the sealing device.
Rubber composition containing rubutadiene rubber and organic peroxide
In an environment where it is exposed to muddy water
Even when used, the desired performance can be maintained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing one embodiment (for supporting wheels of an automobile) of a rolling bearing of the present invention. FIG. 2 is an enlarged view of one sealing device (12a) of the rolling bearing shown in FIG. FIG. 3 is an enlarged view of the other sealing device (12b) of the rolling bearing shown in FIG. FIG. 4 is a sectional view showing another embodiment (for supporting wheels of a railway vehicle) of the rolling bearing of the present invention. FIG. 5 is an enlarged view showing a sealing device for the rolling bearing shown in FIG. 4; FIG. 6 is a schematic sectional view showing a seal rotation tester used for a sealability test. [Description of Symbols] O Rolling bearing 1 Outer ring equivalent member 4 Inner ring equivalent member 8 Outer ring raceway 9 Inner ring raceway 10 Rolling element 11 Retainer 12a, 12b Sealing device 107 Elastic member 217 Elastic member 400 Vehicle unit 402 Bearing 403 Outer ring 404a, 404b Cone Rollers 405a, 405b Inner ring 404c Cage 410 Elastic member 413 Sealing device 413e Dust lip 413f Main lip

Claims (1)

1. An outer race having an outer raceway on an inner peripheral surface, an inner racer having an inner raceway on an outer peripheral surface, and rollingly provided between the outer raceway and the inner raceway. A plurality of rolling elements,
A retainer for rotatably holding the rolling elements at intervals in the circumferential direction and a rolling element between an inner peripheral surface of the outer ring and an outer peripheral surface of the inner ring; In a rolling bearing provided with a seal device for closing an axial opening of a space, the elastic member constituting the seal device is formed of a crosslinkable rubber composition in which acrylonitrile butadiene rubber is mixed with at least an organic peroxide. Rolling bearing characterized.