JP2003227523A - Bearing for water pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing for a water pump provided with a sealing device which is excellent in forming stability and is not degenerated by use in a high- temperature atmosphere or contact with excessive cooling water. <P>SOLUTION: In this bearing 10 for a water pump having a roller body 10b between an outer ring 10a fixed to a casing and a rotation shaft 12 provided with a driving part on one end and an impeller on the other end and a pair of sealing devices 400, each having an elastic member 15b fixed to both ends of the outer ring 10a, which seal a gap from the rotation shaft 12, at least the elastic member 15b of the sealing device on the impeller side is made of a fluoric rubber composition which can be vulcanized containing at least 100 pts.wt. of either of a vinylidene fluoride-tetrafluoroethylene-propylene ternary copolymer and tetrafluoroethylene-propylene binary copolymer, and 3 to 30 pts.wt. of an ethylene-propylene copolymer. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-cooled engine for an automobile.
More details on water pump bearings suitable for gin etc.
Or water in the bearings that support the rotating shaft of the water pump.
Prevents steam etc. from entering, and at the same time grease in the bearing
TECHNICAL FIELD The present invention relates to a bearing provided with a seal device for preventing the leakage of oil. 2. Description of the Related Art As shown in FIG.
The water pump 30 for pumping and circulating is generally
The rotating shaft 12 to which the propeller 32 is fixed is spaced apart in the axial direction.
A plurality of rolling bearings 10 arranged in a casing
38. Cooling water is impeller 32
The mechanical seal 40 disposed between the
More sealed. However, this water pump shaft
At the receiver 10 (hereinafter, sometimes simply referred to as "bearing").
Is that the sliding surface of the mechanical seal 40 with the rotating shaft 12 is water
Since it is in a lubricated state, water vapor etc. leaks and
The water enters the bearing 10 and water vapor and the like further enter the bearing 10.
The bearing 10 is deteriorated by infiltrating into the portion. Therefore,
To prevent air from entering the bearing 10 from the impeller 32 side.
To stop the lubrication grease sealed inside the bearing 10
To prevent leakage, seal the bearing 10 on the impeller 32 side.
Control device is provided. Also, the driving side 31 of the bearing 10
To prevent dust from entering from outside
To prevent leakage of the lubricating grease sealed inside the receiver 10.
For this purpose, a sealing device is provided. The sealing device on the impeller 32 side is, for example,
For example, it has a structure as shown in FIG. 2 as an axial sectional view.
In FIG. 2, the bearing 10 comprises an outer ring 10a and an inner ring.
Between the rotating shaft 12 and the outer ring 10a and the rotating shaft 12.
The held ball 10b and the holding for holding the ball 10b
Container 10c. The sealing device 400 is connected to the sealing plate 15.
And a flinger 20. Of the axial end of the outer race 10a
A sealing plate 15 is disposed in the seal groove 10d. Dense
The sealing plate 15 is composed of a metal core 15a and an elastic material 15b,
The material 15b has three lips 15c, 15d and 15e.
I do. The core metal 15a has an inverted L-shaped cross section.
It is crimped and attached in the seal groove 10d of FIG.
An elastic material 15b is in close contact with the outer surface of the cored bar 15a.
You. Elastic material 15b is made of nitrile rubber, a heat-resistant mark.
Standard fluoro rubber (for example, vinylidene fluoride-hexaf)
Fluoropropylene binary copolymer, vinylidene fluoride-hex
Safluoropropylene-tetrafluoroethylene ternary
Vulcanizable fluoro rubber compositions containing polymers)
The cross section is bifurcated, and the main
The lip portion 15e extends obliquely to the lower right and forms the other side.
The sub lip 15d extends obliquely to the lower left. Ma
In addition, at an intermediate position of the core metal 15a, the elastic material 15b
A third cylindrical lip extending rightward in the figure.
15c is formed. On the rotating shaft 12, a stainless steel
A flinger 20 is arranged. Flinger 20
A small cylinder 20c closely fitted to the rotating shaft 12, and
Large cylinder 20a which is included in the inside and both cylinders are connected in the radial direction
And a flange portion 20b. Elastic material 15b
The third lip portion 15c of the flinger 20 is
a, and the main lip portion 15e is attached to the small cylinder 20c.
And the auxiliary lip portion 15 d is
It comes into contact with the peripheral surface to achieve sealing. [0005] In the sealing device 400, from the outside
If cooling water vapor or water droplets are scattered,
This is received on the outer peripheral surface of the gir 20, and the cooling water is
They do not get off directly. This allows
Deformation or expansion of the sealing plate 15 (particularly, the third lip member 15c)
Can be reduced. On the other hand, sealed inside the bearing 10
The grease or the like that has been applied is applied to the
And the main lip 15e to prevent leakage to the outside.
It has been stopped. Further, fluorine resin having excellent chemical resistance and heat resistance.
Vinylidene fluoride-tetrafluoroethylene
-Propylene terpolymer, tetrafluoroethylene
-Propylene binary copolymers are known. [0007] The recent high performance of the engine
Temperature conditions around the engine are becoming more stringent as
If the ambient temperature of the bearing exceeds 120 ° C
There is a case. However, nitrile rubber has a heat resistance limit of one.
Since it is about 20 ° C, the elastic material of the sealing device for the bearing 10
When nitrile rubber is used as the material for
It hardens and deteriorates, loses elasticity, and in extreme cases the lip
Cracks may occur and seal performance may be impaired
There is. Also, the above-mentioned standard fluoro rubber is heat resistant.
Since the limit is 200 ° C or higher, even under the above temperature conditions
No heat resistance problem, but in contact with additives contained in cooling water
If touched, it deteriorates and deforms, lowering sealing performance
There is a risk that. Therefore, a conventional water pump bearing system has been proposed.
Looking at the material of the elastic material of the ruler device,
No. 93795 discloses a hydrogenated nitrile rubber.
ing. The heat resistance limit of the hydrogenated nitrile rubber is 1
Since the temperature is 50 ° C, the heat resistance under the above
There is no title, but the degree of difference compared to standard fluoro rubber
It deteriorates when it comes into contact with additives contained in cooling water.
It may be deformed and the sealing performance may be reduced.
Therefore, its performance is still not enough. [0009] To improve the above problems, a base rubber
Vinylidene fluoride with excellent chemical and heat resistance
Lafluoroethylene-propylene terpolymer and tetra
Using a fluoroethylene-propylene binary copolymer,
A seal device for a water pump bearing as shown in FIG.
Molding is possible, but new problems such as
Occurs. FIG. 1 shows a seal device for a water pump bearing.
As can be seen from Fig. 2, it is used for ordinary deep groove ball bearings.
More rubber lip parts than the rubber seal device
It takes on a shape. Vinylidene fluoride-tetrafluoroethylene
-Propylene terpolymer and tetrafluoroethylene
-On the other hand, propylene binary copolymers are processable and releasable.
Has the drawback of poor
Is likely to be higher. Therefore, the present invention has the above-mentioned conventional problems.
With excellent molding stability and high
Use in warm atmosphere and contact with excessive cooling water
Bearings for water pumps with a seal device that does not change
The purpose is to provide. [0012] The above objects of the present invention.
Has an outer ring fixed to the casing and a drive unit on one end side.
Between the rotating shaft and the rotating shaft with an impeller on the other end
And each fixed to both ends of the outer ring
The rotating shaft is provided by a pair of sealing devices having an elastic material.
Water pump bearing with seal between
An elastic material of at least the sealing device on the impeller side.
Is vinylidene fluoride-tetrafluoroethylene-propyl
Len terpolymer and tetrafluoroethylene-propylene
100 parts by weight of at least one of the len binary copolymer,
3 to 30 parts by weight of an ethylene-propylene copolymer.
Characterized by comprising a vulcanizable fluoro rubber composition
This is achieved by a water pump bearing. The above vinylidene fluoride-tetrafluoroethylene
-Propylene terpolymer is relatively ternary and therefore relatively
Low proportion of vinylidene fluoride and hexafluoropropyl
Because it does not contain propylene, it can be used with basic compounds such as amines.
Hardly causes a hydrofluoric acid reaction of vinylidene fluoride. Also,
The above tetrafluoroethylene-propylene binary copolymer
Does not contain vinylidene fluoride as a raw material,
Since it does not contain fluoropropylene, basic
Do not cause dehydrofluorination of vinylidene fluoride by compounds
No. Therefore, the seal device of the water pump bearing of the present invention is provided.
It is suitable as an elastic material for the device. In addition, these fluorine
The standard fluororubber (vinylidene fluoride-hexaf
Fluoropropylene binary copolymer or vinylidene fluoride
-Hexafluoropropylene-tetrafluoroethylene
Vulcanizable fluoro rubber composition containing a terpolymer)
All have excellent chemical resistance. But on the other hand molding
Ethylene-propylene copolymer
Improves moldability and mold release by blending a specific amount of body
I do. That is, vinylidene fluoride-tetrafluoroethylene
-Propylene terpolymer and tetrafluoroethylene
A specific amount of at least one of the propylene binary copolymer
Fluororubber composition containing ethylene-propylene copolymer
Material as elastic material for sealing device of water pump bearing
If used, the seal device should be used in a high temperature atmosphere and
Not denatured by contact with cooling water
Good sealing performance can be demonstrated. As a result, water
The bearing performance is not reduced without steam etc.
Absent. Furthermore, moldability and mold release properties have been improved, and molding stability has been improved.
And productivity is high. DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the present invention will be described in detail.
I do. The water pump bearing of the present invention is, for example,
It has the sealing device shown in FIG. That is, the bearing 10
An outer ring 10a, a rotating shaft 12 constituting an inner ring, and an outer ring 10
a ball 10b sandwiched between the
And a retainer 10c for holding the
Sealing device 40 composed of 15 and flinger 20
0 is incorporated. At both ends of the outer ring 10a in the axial direction
The sealing plate 15 is disposed in the groove 10d. sealing
The plate 15 is composed of a metal core 15a and an elastic material 15b,
15b has three lip portions 15c, 15d and 15e
You. The core metal 15a has an inverted L-shaped cross section, and has an outer race 10a.
Is crimped in the seal groove 10d. core
The elastic material 15b is in close contact with the outer surface of the gold 15a. The elastic material 15b is made of fluoro rubber, which will be described later.
And its cross section is bifurcated, forming one of them
Main lip portion 15e extends obliquely to the lower right and forms the other side.
The formed sub lip 15d extends obliquely to the lower left.
In addition, at an intermediate position of the core metal 15a, the elastic material 15b
And extend to the right in the figure to form a third cylindrical lip.
A portion 15c is formed. On the rotating shaft 12, a stainless steel
A flinger 20 is arranged. Flinger 20
A small cylinder 20c closely fitted to the rotating shaft 12, and
Large cylinder 20a which is included in the inside and both cylinders are connected in the radial direction
And a flange portion 20b. Elastic material 15b
The third lip portion 15c of the flinger 20 is
a, and the main lip portion 15e is attached to the small cylinder 20c.
And the auxiliary lip portion 15 d is
It comes into contact with the peripheral surface to achieve sealing. The elastic material 15b is made of vinylidene fluoride.
Including trafluoroethylene-propylene terpolymer
Vulcanizable fluoro rubber composition or tetrafluoroe
Vulcanizable fluorine containing a styrene-propylene binary copolymer
It consists of a raw rubber composition. Component ratio in these copolymers
Is not particularly limited, but vinylidene fluoride-tetrafluoro
Vinylidene fluoride in ethylene-propylene terpolymer
1 to 30 mol%, tetrafluoroethylene 40 to
70 mol%, propylene is preferably in the range of 30 to 60 mol%.
More preferably, vinylidene fluoride is 2 to 5 mol.
%, 40-60 mol% of tetrafluoroethylene, professional
The range of pyrene in the range of 40 to 60 mol% is preferable from the viewpoint of chemical resistance.
is there. Also, tetrafluoroethylene-propylene binary
20-80 mol of tetrafluoroethylene in the copolymer
%, Propylene is preferably in the range of 20 to 80 mol%,
More preferably, 30 to 60 tetrafluoroethylene
% And propylene in the range of 30 to 60 mol%. Ma
In addition, these copolymers have a cross-linking point at the time of cross-linking.
So-called cure site monomers (eg iodine compounds and bromination
Compound) may be copolymerized by several mole% or post-treated after polymerization.
To introduce an unsaturated bond into the copolymer. This
Vinylidene fluoride-tetrafluoroethylene-pro
As a pyrene terpolymer, "BRE" manufactured by DINEON
LJ-298005 "(trade name) and" A "manufactured by Asahi Glass Co., Ltd.
FLAS SP "," AFLAS SZ "(trade name), etc.
Can be used. Also, tetrafluoroethylene
-As a propylene binary copolymer, "A" manufactured by Asahi Glass Co., Ltd.
FLAS 150P "(trade name) and other commercially available products
Wear. In addition, moldability such as mold releasability and workability is improved.
To improve the width, ethylene-propylene copolymer
Is blended. Suitable ethylene-propylene copolymer
As a third component with ethylene and propylene
1,4-hexadiene, dicyclopentadie
Non-conjugated diene such as 5-ethyllidene-2-norbornene
Terpolymers obtained by copolymerizing ene at a ratio of 10 mol% or less
Can be mentioned. Also, ethylene and propylene
Is a ratio of ethylene: propylene = 50: 5 in polymerized units.
0 to 90:10 (mol%) is preferable. Propylene ratio
If the amount is too large, especially ethylene-propylene binary copolymerization
In the case of body, vulcanization with organic peroxides becomes difficult and
I don't. This ethylene-propylene copolymer is fluorinated.
Vinylidene-tetrafluoroethylene-propylene ternary
Copolymer and tetrafluoroethylene-propylene binary
3 to 100 parts by weight of at least one of the copolymers
30 parts by weight, preferably 5-20 parts by weight
It is. The compounding amount of the ethylene-propylene copolymer is triple
If it is less than 30 parts by weight, the effect of improving moldability is insufficient, and
If it exceeds parts by weight, the heat resistance of the rubber composition as a whole and
It is not preferable because chemical resistance is lowered. The ethylene-propylene copolymer is fluorinated.
Vinylidene-tetrafluoroethylene-propylene ternary
Copolymer or tetrafluoroethylene-propylene
When a small amount is blended with the binary copolymer, fluorine atoms are separated.
Vinylidene fluoride-tetrafluoro abundantly present in
Ethylene-propylene terpolymer or tetrafluoroe
Low compatibility with Tylene-propylene binary copolymer
Therefore, it is difficult to stay in the molded body, and there is a large amount on the surface
The likelihood increases. For this reason, the internal mold release with a small amount of compounding
Works effectively as a dispersant, greatly improving mold release during vulcanization molding.
Improves accuracy even with rubber seal devices of complex shapes
Be able to mold. Also, the surface of the rubber seal device
Of ethylene-propylene copolymer in water
With vinylidene fluoride-tetrafluoroethylene-propyl
Len terpolymer or tetrafluoroethylene propylene
Complementation of core metal, etc., was difficult with propylene copolymer alone.
Strong and stable vulcanization adhesion to a strong member becomes possible. this
The effect is that the EPDM type
The use of ethylene-propylene copolymer of
Become author. The method for vulcanizing the above copolymer is not particularly limited.
It is a usual method of vulcanizing fluoro rubber,
Sulfur or peroxide vulcanization can be applied. example
For example, in the case of polyol vulcanization,
The compound is a conventionally known polyhydroxy aromatic compound.
Substances or fluorinated polyhydroxy aliphatic compounds can be used
And hydroquinone, 2,2-bis (4-
Hydroxyphenyl) propane [bisphenol A],
2,2-bis (4-hydroxyphenyl) perfluoro
Propane [bisphenol AF] and the like are preferably used.
You. These are also alkali metals, alkaline earth metals,
Salts such as organic onium compounds may be used. These poly
The compounding amount of the all vulcanizing agent is 100 parts by weight of the above copolymer.
In the range of 0.5 to 10 parts by weight.
If so, there is no danger of insufficient vulcanization or overvulcanization. On the other hand, a vulcanizing agent for peroxide vulcanization
Is an organic peroxide having a -O-O- bond in its molecule.
Organic compounds, specifically peroxyketters
, Dialkyl peroxide, diacyl peroxide
, Peroxyester, hydroperoxide, etc.
No. More specifically, benzoylpa
-Oxide, dicumyl peroxide, di-t-butyl
Luper oxide, 2,5-dimethyl-2,5-di (t
-Butylperoxy) hexane, 2,5-dimethyl-
2,5-di (t-butylperoxy) hexyne-3,
α, α'-bis (t-butylperoxy) -p-diiso
Propylbenzene, 1,1-bis (t-butyl peroxy
B) -3,3,5-trimethylcyclohexane, etc.
it can. The compounding amount of these organic peroxides is
0.5 to 10 parts by weight per 100 parts by weight
In this range, there is no danger of insufficient vulcanization or over vulcanization.
Absent. In vulcanizing the polyol, an acid acceptor,
And metal oxides and metal hydroxides as vulcanization aids
Is blended as an essential component. An example of this is hydroxyl
Calcium oxide, magnesium hydroxide, calcium oxide,
Examples include zinc oxide, lead oxide, and magnesium oxide.
However, the combination of calcium hydroxide and magnesium oxide is preferred.
Good. Mixing of these metal oxides and metal hydroxides
The amount is 0.5 to 50 parts by weight based on 100 parts by weight of the copolymer.
Parts by weight, more preferably in the range of 1 to 30 parts by weight.
is there. Further, as a vulcanization accelerator, an onium salt (quaternary ammonium salt) is used.
Salt or quaternary phosphonium salt)
No. As a specific example, as the quaternary ammonium salt,
Tetrabutylammonium hydrogen sulfate, tetramethyl hydrogen sulfate
Tylammonium, tetraethylammonium hydrogen sulfate
System, trioctylmethyl ammonium hydrogen sulfate, sulfuric acid aqueous solution
Tridecyl methyl ammonium sulfate, trimethyl hydrogen sulfate
Benzyl ammonium and the like are exemplified. Class 4 phospho
As the sodium salt, tetrabutylphosphonium chloride
Ride, tetrabutylphosphonium bromide,
Libutyl (methoxypropyl) phosphonium chloride
Id, trioctylmethylphosphonium chloride
Do, tridodecylmethylphosphonium chloride, etc.
And two or more kinds may be used in combination. these
The onium salt is added in an amount of 100 parts by weight of the above copolymer.
In general, the amount is preferably in the range of 0.3 to 5 parts by weight.
If there is no vulcanization, there is no danger of insufficient vulcanization, over vulcanization and early vulcanization
Absent. In the case of peroxide vulcanization, vulcanization
Unsaturated polyfunctional compounds are used as auxiliaries, for example,
Polyallyl compound, methacrylate compound, divinyl compound
Products, polybutadiene and the like. Above all, Triari
Luisocyanurate and triallyl cyanurate are preferred
No. The amount of these unsaturated polyfunctional compounds is
0.5 to 20 parts by weight per 100 parts by weight of combined, preferably
Is 1 to 10 parts by weight. The above-mentioned copolymer is further provided with a conventionally known supplement.
Carbon black, cellite used as a strong filler
Of silica, clay, talc, calcium carbonate, etc.
Agents, other pigments, dyes, antioxidants, antioxidants,
Add and mix additives such as stabilizers, processing aids, plasticizers, release agents, etc.
Is also good. Using the above components, the sealing device 400
The method for obtaining the elastic material is not particularly limited.
Vinylidene fluoride-tetrafluoroethylene
-Propylene terpolymer or tetrafluoroethylene
Propylene copolymer, filler and other additives
Add the additive to a rubber kneading roll, pressure kneader or bumper.
-Using a conventionally known rubber kneading device such as a mixer
And can be mixed uniformly. The kneading conditions are
Although not particularly limited, it is usually 5 to 30 to 80 ° C.
By kneading for 60 minutes, sufficient amounts of various additives can be obtained.
Can be dispersed. The elastic member 15b of the sealing device 400
Although there is no particular limitation on the manufacturing method for
Heat the raw rubber composition while pressing it in the mold
Well-known such as compression molding, transfer molding, injection molding, etc.
Can be produced by the rubber molding method described above. For example,
In the case of compression molding, a core metal with an adhesive applied in advance to the mold
(Forming the core of the sealing device)
A sheet of the unvulcanized rubber composition produced in
It is manufactured by pressure vulcanization at 0 to 250 ° C for about 3 minutes to 2 hours.
Can be built. Also, after the obtained elastic material 15b
By performing vulcanization, the vulcanization is completed at the same time
In addition, the volatilization of the extra volatile component is performed by the elastic material 15b.
It is preferable because it has an effect to improve the physical properties of
It is. The post-vulcanization conditions are not particularly limited.
For example, at a temperature of 150 to 250 ° C.,
Heat treatment can be performed. As the adhesive used for bonding with the core metal,
Many ethylene-propylene copolymers are present on the surface
Taking advantage of this, silane coupling with vinyl and amino groups
When a silane-based adhesive containing a coupling agent is used,
Rubber seal for water pumps with an adhesive strength above a certain level
This is preferable because an apparatus can be obtained. Silane with vinyl group
As the coupling agent, for example, γ-methacryloxyp
Ripirtrimethoxysilane and the like can be mentioned. This vinyl
The silane coupling agent having a group is a hydrolyzable alcohol.
Coxy groups hydrolyze to silanol groups, and the silanol
Group reacts with hydroxyl group on metal surface (dehydration condensation)
Are chemically bonded by the
Nyl group is a double bond or peroxide present in the structure
Is incorporated into the structure during the cross-linking reaction by
Strong bonding strength to chemically bond the composition and metal
Is obtained. 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. (First experiment) First, the crosslinking shown in Table 1 was carried out.
Materials other than the accelerator and vulcanization accelerator are put into the Banbury mixer.
Then, mastication was performed at a mixer temperature of 80 ° C. Then,
Remove the kneaded mixture from the Banbury mixer and remove the rubber
It was put into two rolls for kneading. And the roll temperature 5
While controlling the temperature to 0 ° C, the vulcanization accelerator (or
Bridge agent), knead until uniform, and
A 2.2 mm unvulcanized rubber sheet was produced. Next, the unvulcanized rubber sheet is 150 mm in length and width.
Insert into a 2mm thick mold at 170 ° C for 20 minutes, pressure 5
0kgf / cm ^Two And vulcanization molding was performed. Further examples
1, Example 2, Comparative Example 1 and Comparative Example 3
After being taken out of the oven, it was subjected to secondary vulcanization in an oven. Secondary
The vulcanization conditions were as follows: Example 1 was at 200 ° C. for 4 hours, and Example 2 was
24 hours at 230 ° C, Comparative Example 1 at 200 ° C for 4 hours, ratio
Comparative Example 3 was at 180 ° C. for 4 hours. [Table 1] [0033] The obtained vulcanized rubber sheet was JIS dumbbell
Punched into the shape of No. 3 test piece,
It was measured. Table 2 shows the results. Hardness test: JIS with three dumbbell specimens stacked
The hardness was measured according to K 6301. Tensile test: Universal test for the above dumbbell specimens
The tensile strength and tensile elongation at break were measured using a machine. Volume change rate: The above dumbbell test piece was placed at 150 ° C.
1 week in CII LLC (diluted to 50% with water)
After immersion, the volume change before and after immersion was determined. Molding defect rate: Rubber for water pump bearing shown in Fig. 2
After molding 100 seals, the lip may be damaged when the mold is released.
The presence or absence and the like were examined to determine the molding failure rate. [Table 2] As is clear from the results in Table 2, the present invention
Vinylidene fluoride-tetrafluoroethylene in the range
-Propylene terpolymer or tetrafluoroethylene
Ethylene per 100 parts by weight of propylene-copolymer
3-30 parts by weight of a len-propylene copolymer was blended
All of the test pieces made of the rubber composition have a small volume change rate.
No molding failure was observed. The distribution of vinylidene fluoride
As the mixing ratio decreases, the volume change rate decreases.
Example 1 especially containing no vinylidene fluoride
The test piece has the smallest volume change rate. On the other hand, using hydrogenated nitrile rubber
Comparative Example 2, a vinylidene fluoride standard fluororubber
-Comparison using hexafluoropropylene binary copolymer
Example 3 Each test piece of Comparative Example 4 using nitrile rubber was swollen.
Is large and does not contain an ethylene-propylene copolymer
In the test piece of Comparative Example 1, the molding failure rate was remarkably large.
It was found that the usability was low. (Second Experiment) Using the test apparatus shown in FIG.
The heat resistance of the bearing provided with the sealing device having the configuration shown in FIG.
A test and a water resistance test were performed. The test device shown in FIG.
The bearing supporting the rotating shaft is connected to the heater via the housing.
As well as cooling to the end of the bearing with a metering pump.
It is configured to supply a constant amount of rejected water. With this test equipment,
Change over time of the performance of the elastic material of the seal device provided at the bearing end
Was examined. The elastic material of the sealing device used in the above test was
Example 1, Example 2, Comparative Example 2,
The composition was the same as that of Comparative Example 3. The production of the test bearing was first performed in the same manner as in the first experiment.
The unvulcanized rubber composition was prepared in the same manner as
Insert the cored bar 15a on which the vulcanized rubber sheet was previously coated with an adhesive.
Into the mold and pressure under the conditions of primary vulcanization described in Table 1.
30kgf / cm ^Two And vulcanization molding was performed. In addition, a mold
Vulcanized as described in Table 1
The post-vulcanization was performed under the following conditions. Then, the obtained sealing plate 15
A flinger 20 is mounted on the bearing, and it is assembled into the bearing 10 and tested.
A bearing was made. The test conditions are as follows. -Bearing temperature: 150 ° C-LLC: LLC manufactured by CCI Inc.-LLC water injection amount: 50 ml / min-Rotational speed: 8000 rpm-Test time: 1000 hours The evaluation item is the hardness of the main lip 15e.
Changes and deformation of the third lip (wavy). In addition, of hardness
The measurement is based on JIS K 6253, IRHD (International R
ubber Hardness Degree)
Was. Table 3 shows the results. [Table 3] As is clear from the results in Table 3, the present invention
Elasticity of the rubber compositions of Examples 1 and 2 in the range
The seal device made of material has a small change in hardness of the main lip.
And no deformation of the third lip was observed.
One that has LLC resistance and excellent sealing properties
I think that the. Using hydrogenated nitrile rubber as raw rubber
The rubber composition of Comparative Example 2 is a standard rubber
Vinylidene fluoride-hexafluoropropylene 2
The elastic material is formed from the rubber composition of Comparative Example 3 using the terpolymer.
Better than the sealing device made, but the hardness of the main lip
Whether the change is large and the third lip is deformed
However, the sealing performance is lower than that of the bearing of the embodiment, and the bearing life is shorter.
Seems to be. As described above, the water of the present invention is
According to the pump bearing, the elastic material of the sealing device is made of vinyl fluoride.
Riden-tetrafluoroethylene-propylene ternary weight
Merged and tetrafluoroethylene-propylene binary copolymer
Excellent LLC resistance because it contains at least one of coalescing
To exhibit good sealing performance over a long period of time
Is passed through the mechanical seal from the impeller side.
Stable shaft without water vapor etc. entering the bearing
Performance can be guaranteed. Also, a small amount (3 to 30 parts by weight) was blended.
Many ethylene-propylene copolymers are present in the surface layer
Therefore, adhesion to metal, mold release, and workability are improved.
Of a complicated shape that is firmly bonded and integrated with the cored bar.
Sealing device for water pump bearings enables stable production
It will work. Furthermore, an inexpensive ethylene-propylene copolymer
Combined, lower cost.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an axial sectional view showing an example of a water pump to which the present invention is applied. FIG. 2 is an axial sectional view showing an example of a sealing device. FIG. 3 is a sectional view of a test apparatus. [Description of Signs] 10 Bearing 10a Outer ring 12 Rotary shaft 15 Sealing plate 15a Core 15b Elastic material 20 Flinger 30 Water pump 32 Impeller 400 Sealing device

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) (C08L 27/18 23:16) (72) Inventor Takahiko Uchiyama 1-chome 50-50 Kumeinuma Shinmei, Fujisawa-shi, Kanagawa No. N-Seiko Co., Ltd. F-term (reference) 3J016 AA01 BB03 4J002 BB111 BB151 BB152 FD010 FD140 FD150 FD160 GM05

Claims (1)

Claims: 1. A rolling element is provided between an outer ring fixed to a casing and a rotating shaft having a driving portion at one end and an impeller at the other end, and the outer ring. By a pair of sealing devices each having an elastic material fixed to both ends of
In a bearing for a water pump in which a seal is provided between the rotating shaft and the rotating shaft, at least the elastic material of the sealing device on the impeller side is made of vinylidene fluoride-tetrafluoroethylene-
Propylene terpolymer and tetrafluoroethylene
A water pump bearing comprising a vulcanizable fluororubber composition containing 100 parts by weight of at least one of a propylene binary copolymer and 3 to 30 parts by weight of an ethylene-propylene copolymer.