JPH1061777A - Synthetic resin-made seal ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal ring which can be used even in a condition of high oil pressure with good assembly performance. SOLUTION: This synthetic resin-made seal ring is composed of a resin composition containing 85 to 60wt.% of a heat-resistant resin of polyether ketone resin or the like and 15 to 40wt.% of an additive of fibrous reinforcing material (carbon fiber) or the like, and an external diameter thereof is set to 10 to 30mm. Alternatively, based on 100 pts.wt resin composition containing 85 to 60wt.% of the heat-resistant resin and 15 to 40wt.% of the additive of fibrous reinforcing material or the like, the seal ring consists of a lubricant-contained resin composition adding 1 to 20 pts.wt. of lubrication giving agent of PTFE, graphite, molybdenum disulfide or the like, and an external diameter thereof is set to 10 to 30nm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal ring made of synthetic resin, and more particularly, to a seal ring made of synthetic resin or the like having a high fluid pressure such as oil to be sealed, such as a continuously variable transmission or a power steering device in an automobile or the like. A seal ring made of synthetic resin.

[0002]

2. Description of the Related Art In general, a continuously variable transmission (continuously variable transmission: hereinafter abbreviated as CVT) generally uses a driving force of a driving wheel and a driving force in accordance with a traveling condition of a vehicle which varies widely. By changing the speed, the performance of the internal combustion engine of the vehicle is exhibited.
As shown in FIG. 4, the CVT mechanism includes a fixed pulley 2 fixed to the driven shaft 1 and a movable pulley 3 attached to the fixed pulley 2 so as to be capable of being separated from the fixed pulley 2. By increasing or decreasing the width of the formed groove, the rotational radius of the belt wound around the pulley is increased or decreased to transmit power and change the gear ratio.

The driven shaft 1 of the CVT is provided with a hydraulic clutch 4, and the hydraulic clutch 4 and the movable pulley 3 are provided with hydraulic chambers 5 and 6, respectively.
The lubricating oil in the hydraulic chambers 5 and 6 is supplied to the hydraulic passages 7 and 8
And is supplied to the outer peripheral surface of the driven shaft 1 and members around it. For this reason, a large number of oil seal rings 9 are provided at sliding portions on the driven shaft 1 or the like (for example, inside the shaft groove 10) to prevent leakage of lubricating oil.

The oil seal ring 9 is required to have many characteristics such as low friction, excellent wear resistance, and sufficient oil sealing without damaging a mating material such as the driven shaft 1. .

[0005] Generally, as an oil seal ring material,
A tetrafluoroethylene resin (hereinafter abbreviated as PTFE) is used.

[0006]

SUMMARY OF THE INVENTION However, CVT
In this case, the oil pressure of the lubricating oil is 3 to 6 MPa, which is considerably higher than the oil pressure of the lubricating oil in normal applications (AT, etc.) of 1 to 2 MPa. Is required.

[0007] Such an oil seal ring has a heat resistance that can withstand a normal use temperature of 40 ° C or more, and a heat resistance that can withstand an instantaneous maximum temperature of about 180 ° C.
It is required to have heat resistance that does not melt at a continuous use temperature of ° C.

Further, since the outer diameter of the oil seal ring 9 is as small as 10 to 30 mm, the oil seal ring 9 has good assembling property so as not to cause a problem such as breakage when assembling the oil seal ring. Required.

Further, in the above-mentioned PTFE oil seal ring, when the PV value (the product of the pressing pressure (P) and the sliding speed (V)) increases, the ring itself wears and the creep increases, so that a sufficient oil seal is obtained. There is also a problem that the state cannot be obtained.

In addition, the oil seal ring may be heated to a high temperature due to heat generated from various parts during high-speed movement.
In addition, cold resistance that can withstand use in cold regions is required,
Specifically, characteristics that can withstand a wide range of temperature conditions of −40 to 180 ° C. are also required.

Therefore, an object of the present invention is to solve the above-mentioned problems and to be able to be used even in a high oil pressure state, to have excellent sealing properties, to have good friction and wear characteristics, and to have a good assembling property. It is to provide a seal ring.

[0012]

In order to solve the above-mentioned problems, in the present invention, a heat-resistant resin of 85 to 60% by weight is used.
Thus, a synthetic resin seal ring for high-pressure fluid sealing comprising a resin composition containing 15 to 40% by weight of an additive was prepared.

Further, the composition comprises 1 to 20 parts by weight of a lubricity-imparting agent per 100 parts by weight of a resin composition containing 85 to 60% by weight of a heat-resistant resin and 15 to 40% by weight of an additive. This is a seal ring made of synthetic resin for high-pressure fluid sealing.

The above-mentioned additives may be in the form of fibers, rods, granules,
Any type of additive such as a sphere, a scale, and a plate can be used.

Alternatively, in order to solve the above-mentioned problems, the present invention comprises a resin composition containing 85 to 60% by weight of a heat-resistant resin and 15 to 40% by weight of a fibrous reinforcing material,
The outer diameter of the seal ring was 10 to 30 mm.

[0016] Alternatively, a lubricant obtained by adding 1 to 20 parts by weight of a lubricity-imparting agent to 100 parts by weight of a resin composition containing 85 to 60% by weight of a heat-resistant resin and 15 to 40% by weight of a fibrous reinforcing material. Containing resin composition having an outer diameter of 1
It was a seal ring of 0 to 30 mm.

Further, the fibrous reinforcing material has a fiber length of 0.1.
A fiber having a fiber diameter of 1 to 25 μm can be adopted.

The heat-resistant resin is an aromatic polyetherketone resin, and the fibrous reinforcing material may be carbon fiber.

The above CVT generally has an outer diameter of 10 to 30.
An oil seal ring having a thickness of 2 mm is used, and the seal ring made of the composition of two or more components has good sliding characteristics and good incorporation. In addition, the seal ring can be used even when the hydraulic pressure is high.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The seal ring of the embodiment can be applied to any sealing device in which fluid pressure such as hydraulic pressure, water pressure, and atmospheric pressure acts. A CVT using the oil seal ring as an example has the above-described mechanism (FIG. 4), and the size of the oil seal ring used for this is often 10 to 30 mm in outer diameter.
The hydraulic pressure applied to the oil seal ring of the present invention is:
The pressure is 3 to 6 MPa, which is higher than that of a general seal ring, and the rotation speed of the CVT is 100 rpm or more, and is usually used at a high speed of about 1000 to 10000 rpm.

Here, a sealing device in which at least one of the devices sealed with a shaft or a housing or the like is mainly driven to rotate relatively will be described using the CVT as an example.

In order to obtain a seal ring having a predetermined outer diameter and withstanding the above-mentioned hydraulic pressure, a heat-resistant resin 85 is used as the material.
A resin composition containing 〜60% by weight and 15-40% by weight of a fibrous reinforcing material is used. Further, a lubricant-containing resin composition in which a lubricity-imparting agent is added in an amount of 1 to 20 parts by weight, preferably 5 to 15 parts by weight, based on 100 parts by weight of the above-described resin composition can also be used.

The heat-resistant resin used in the present invention is preferably an aromatic heat-resistant resin having an aromatic ring in the main chain of the polymer in an amount of, for example, 10% by weight or more, preferably 20 to 100% by weight. Particularly, those having excellent mechanical properties, electrical properties and chemical resistance in addition to high heat resistance and combustion resistance are preferable.

Examples of such heat resistant resins include polyether ketone (hereinafter abbreviated as PEK), polyether ether ketone (hereinafter abbreviated as PEEK),
Polyether nitrile resin (hereinafter abbreviated as PEN), aromatic thermoplastic polyimide resin (hereinafter TPI)
Abbreviated. ), Polyamide 4-6 resin (hereinafter, PA4
Abbreviated as -6. ) And polyphenylene sulfide resin (hereinafter abbreviated as PPS). A mixture of two or more of these may be used. Further, a heat-resistant resin mainly composed of a synthetic resin that can be injection-molded is preferable.

The aromatic heat-resistant resin such as the PEK-based resin containing PEEK or the like has a lower limit of the melting point of 280 ° C. or more, preferably 300 ° C. or more, more preferably 330 ° C.
Above, the upper limit is 550 ° C or lower, preferably 500 ° C or lower, more preferably 450 ° C or lower,
An oil seal ring having excellent heat resistance and injection moldability can be manufactured.

Among the aromatic heat-resistant resins, crystalline resins are preferred because they satisfy a higher degree of heat resistance. For example, the maximum crystallinity is at least 20% or more, preferably 30 to 80%, Preferably, 40 to 70% is excellent in heat resistance and breakage resistance. However,
The heat-resistant resin used in the present invention may not necessarily contain an aromatic ring, and may be a heat-resistant resin outside the above-described range of the melting point and the numerical value of the crystallinity, for example, a thermosetting resin other than the above. Or it may be an amorphous resin.

The melt viscosity of these heat-resistant resins is such that the shear rate is 1 × (10 ² to 10 ⁴ ) sec ⁻¹ , preferably 1 ×.
It is 300 poise to 100,000 poise, preferably 500 poise to 10,000 poise, more preferably 1,000 to 6,000 poise, and more preferably 1,000 to 6,000 poise under the conditions of 10 ³ sec ⁻¹ and a resin temperature of 300 to 500 ° C.
000-4000 poise. If the melt viscosity is less than 300 poise, mechanical properties such as cleave resistance are reduced in a high temperature range of 150 ° C. or more, and deformation is liable to occur. On the other hand, if it is larger than 100,000 poise, the moldability is inferior depending on the composition material, and the flexibility is reduced, so that a seal ring is formed on a groove (a portion indicated by reference numeral 10 in FIG. 4) such as a shaft and a piston. It is not preferable because it is difficult to incorporate. The melt viscosity of PEEK is 1 × 1
0 ³ sec ^-1 , about 1500-450 at 400 ° C resin temperature
0 poise.

As the above-mentioned polyether ketone resin, a ketone polymer having an ether bond can be used.
(In each case, n represents an integer.)

Each of these is a crystalline resin, and is not only composed of repeating structural units of Chemical Formulas 1 to 4, but also of Chemical Formulas 5 and 6 below (in each case, n represents an integer). May be a copolymer of the polymer represented by the formula: The proportion of the structure of Chemical Formula 1 to Chemical Formula 4 in such a copolymer is in the range of 50% by weight or more, preferably 70% by weight or more, more preferably 80% to 100% by weight of the whole polymer. If the copolymer is a suitable one, it can exhibit its inherent properties as a ketone resin such as heat resistance.

The most preferable polyetherketone resin in terms of heat resistance is thermoplastic wholly aromatic PEK or thermoplastic wholly aromatic PEEK in which all bonds between the ether group and the ketone group are composed of aromatic rings.

[0031]

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[0032]

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[0033]

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[0034]

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[0035]

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[0036]

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Specific examples of these commercially available products include:
VICTREX-PEK220G manufactured by Victrex Limited as PEK of Chemical Formula 1, PE of Chemical Formula 2
EK made by Victrex Limited: VICTR
EX-PEEK150P (mp 334-337 ° C),
Hoechst as PEEK of formula (3): HOSTAT
As the PE of EC, (Chem. 4), ULTRA PEK-A1000 manufactured by BSF Inc. may be mentioned.

As PEN, Idemitsu Kosan Co., Ltd .: I
D300, manufactured by Mitsui Toatsu Chemicals Co., Ltd .: Aurum 4
50, PA46 manufactured by Nippon Synthetic Rubber Co .: Stanyl T
W300, manufactured by Unitika Ltd .: F5001, PP
Examples of S include K4, T4, LCX-7 manufactured by Topren Corporation.

Fiber used in the present invention (including whisker)
Specific examples of the shape reinforcing material include carbon fibers (carbon fibers). As carbon fiber, pitch type, PA
There are N type and the like, but pitch type is preferable. This is because pitch-based carbon fibers have a lower aggressiveness to a mating material and are more excellent in wear resistance than PAN-based carbon fibers.

The average fiber length of the carbon fibers is 0.01 to 1 mm
Is preferable, and 0.01 to 0.3 mm is more preferable. Further, the average fiber diameter is preferably 1 to 25 μm, and 5 to 25 μm.
μm is more preferred, and 10-20 μm is even more preferred.
If the average fiber length is less than 0.01 mm, the reinforcing effect of the matrix itself of the resin composition is impaired and the mechanical properties are reduced. If it exceeds 1 mm, uniform dispersion during mixing is extremely difficult, and The properties are impaired and the quality is reduced. If the average fiber diameter is less than 1 μm, coagulation between the fibers occurs, making uniform dispersion difficult, and 25 μm
This is because if it exceeds, the mating material will be worn. The size of the whisker has an average fiber diameter of 0.1 μm or more and less than 1 μm,
Those having an average fiber length of 1 μm or more and less than 10 μm are preferred.

The average tensile strength of the carbon fiber is 490-98.
0 MPa is preferable, and the average tensile modulus is 30 to 50 GP.
a is preferred. When the average tensile strength exceeds 980 MPa, the shearing force of the carbon fiber itself is strong, so that the carbon fiber is not sheared when sliding with the counterpart material, but escapes from the base resin and intervenes with the counterpart material, which adversely affects wear. That's why.
When the pressure is less than 490 MPa, it becomes difficult to provide an oil seal ring having physical properties such as desired mechanical strength and heat deformation temperature under high pressure fluid pressure and high temperature use.

The carbon fibers having a tensile strength in the above range are:
Since it is a fiber having an appropriate mechanical strength, a synthetic resin oil seal ring using the fiber has an appropriate mechanical strength. For this reason, it can be expected to prevent the sliding partner from being attacked and worn. As a carbon fiber satisfying the above conditions, a pitch-based carbon fiber is preferable in terms of mechanical strength, damage to a sliding contact material, and availability (price), and is also preferable from a comprehensive viewpoint.

As a commercially available example of pitch-based carbon fiber, Kureka M207S (fiber diameter: 12 to 13 μm) manufactured by Kureha Chemical Industry Co., Ltd.
m) etc., and there is a series of Creca Chop M201F (average fiber diameter 12.5
μm, average fiber length 0.13 mm), M201S (average fiber diameter 14.5 μm, average fiber length 0.13 mm), M201S
107T (average fiber diameter 18.0 μm, average fiber length 0.7
0 mm).

The PAN-based carbon fiber can be manufactured by heating and baking acrylic fibers such as polyacrylonitrile fibers. Depending on the heating temperature, a predetermined tensile modulus can be obtained, for example, about 1000 to 1500.
When heated at ℃, tensile modulus is 200-350 GP on average
a, Tensile strength is 3000-6000 MPa on average.
Further, by heating at about 2000 ° C., the tensile elastic modulus was increased to an average of 35%.
0-500 GPa, preferably 400-500 GP on average
a can also be used. Therefore, the PAN-based carbon fiber is
It is considered that a fiber having a high tensile strength can have a tensile strength in the range of 2000 to 6000 MPa on average depending on the heating temperature, and can also produce a fiber having an average in the range of 2500 to 3000 MPa on demand. If these values are too low, reinforcement with respect to compression creep cannot be expected, and if these values are too high, it is expected that they will attack mating materials such as shafts, pistons and cylinders.

Examples of this PAN-based carbon fiber include the “Vesfight” (trade name) series manufactured by Toho Rayon Co., and specific examples thereof include Vesfight HTA.
-CMF-0040-E, Vesfight HTA-CMF
-0160-E, Vesfight HTA-CMF-100
0-E, Vesfight HTA-C6-E, etc.
Fiber length 6 mm). In addition, the “Torayca” (trade name) series manufactured by Toray Co., Ltd. is also a general example, and specific examples thereof are Torayca MLD-300,
0 and the like. These pitch-based and PAN-based carbon fibers are less susceptible to chemicals such as acids and alkalis,
It also has abrasion resistance.

In order to enhance the adhesion between the fibrous reinforcing material such as carbon fibers and the heat-resistant resin and to improve the mechanical properties and the like of the seal ring, the surface of these carbon fibers is made of epoxy resin, The surface treatment may be performed with a treatment agent containing a polyamide resin, a polycarbonate resin, a polyacetal resin, or the like, or a silane coupling agent such as an epoxysilane or aminosilane.

The mixing ratio of the aromatic heat-resistant resin and the fibrous reinforcing material in the resin composition is such that the aromatic heat-resistant resin is 8%.
It is preferable that the content is 5 to 60% by weight and the fibrous reinforcing material is 15 to 40% by weight. If the fibrous reinforcing material is less than 15% by weight, little improvement in wear resistance can be expected. On the other hand, if the content exceeds 40% by weight, the melt flowability of the resin composition is remarkably reduced, and the moldability is decreased. This is because the seal ring may be broken when assembled.

The seal ring according to the present invention has an outer diameter of 10 to 30 mm, preferably 10 to 25 mm, and more preferably 2 to 25 mm.
Those having a size of less than 5 mm reduce the friction torque during sliding. More specifically, the length of at least one of the rectangular cross sections of the seal ring (the width of the rectangular cross section and the thickness of the side surface)
However, 5/100 to 15/100, preferably 6/100 to 12/100, more preferably 8/1 of the ring outer diameter.
The proportional relationship of 00 to 10/100 reduces the friction torque during sliding.

For this reason, a resin composition comprising the above-mentioned aromatic heat-resistant resin and a fibrous reinforcing material is used as the resin composition, and sufficient lubrication can be obtained without adding a lubricity-imparting agent or filler. Properties and lubricity can be obtained. The development length of such a seal ring is 100 mm or less, preferably 80 mm or less, and more preferably 30 to 70 mm. When the high-pressure fluid is oil, the oil itself also functions as a lubricity-imparting agent, so that further reduction in friction torque and improvement in wear resistance can be expected.

If the amount of the lubricity-imparting agent is large, the formability of a small oil seal ring having an outer diameter of 10 to 30 mm is reduced. for that reason,
The seal ring of the present invention may be molded using a material in which a lubricity-imparting agent is added to the resin composition in an amount that does not impair moldability.

The amount of the lubricity-imparting agent added is 10 to 3 in the outer diameter.
1 to 20 parts by weight, preferably 100 parts by weight, based on 100 parts by weight of the resin composition comprising the aromatic heat-resistant resin and the fibrous reinforcing material, so that the moldability when forming a small oil seal ring such as 0 mm is not reduced. Is preferably added in an amount of 5 to 15 parts by weight. In the case where the seal ring is designed with appropriate specifications according to the fluid control device or the like, it is not always necessary to set the outer diameter within the above range.

Examples of the lubricity-imparting agent include fluorinated compounds such as fluororesins, molybdenum compounds such as graphite and molybdenum disulfide, and tungsten compounds such as tungsten disulfide, and sulfides such as these, mica, and carbon. Or aromatic polyesters such as econols. Further, those having a temperature (for example, 350 ° C. or higher) higher than the melting temperature (for example, melting point) of the resin composition at the time of injection molding such as melt-mixing molding are also preferable as the lubricity imparting agent.

Examples of the fluororesin include PTFE, tetrafluoroethylene-perfluoroalkyl (propyl) vinyl ether copolymer (PFA), and tetrafluoroethylene-hexafluoropropylene copolymer (FE
P), polychlorotrifluoroethylene (PCTF
E), tetrafluoroethylene-ethylene copolymer (E
TFE), chlorotrifluoroethylene-ethylene copolymer (ECTFE), polyvinylidene fluoride (P
VDF), polyvinyl fluoride (PVF), tetrafluoroethylene-hexafluoropropylene-perfluoroolefin (alkyl vinyl ether) copolymer (EPE), and the like.

Among them, perfluoro fluororesins such as PTFE, PFA, FEP, etc.
Alternatively, it is stable because it is completely surrounded by oxygen, and has excellent slidability and heat resistance. These fluorine-based resins, for example, injection-moldable fluorine resins, may be used as the main component of the seal ring.

Perfluoro fluororesins have a relatively high differential thermal decomposition onset temperature and are therefore preferred. For example, PTFE, P
The thermal decomposition points of VDF are about 490 ° C. and about 350 ° C., respectively.
5 ° C, about 460 ° C, among which PTFE, PFA,
FEP and the like are preferable because of their excellent high-temperature characteristics. For this reason, it can relatively endure the heat history in the process of melting the composition containing the resin into a seal ring. In particular, the decomposition point of PTFE is preferably 100 to 200 ° C. higher than that of a ketone resin having a melting temperature of about 330 to 390 ° C. In addition, PT
The resin composition containing FE alone or PTFE as a main component has a very high melt viscosity and a melt viscosity at 340 to 380 ° C. of about 11 to 10 ¹² poise or more. It may be said that it is difficult or impossible to manufacture.

When PTFE is added in powder form to the heat-resistant resin, it can be used in powder form without any particular limitation on its shape and size, but it is a granular PTFE having an average particle size of 70 μm or less. (Preferably 1 to 50 μm, more preferably 3 to 30 μm) is preferable for making the resin composition uniform.

When PTFE is used as an additive or a lubricity imparting agent in the present invention, the PTFE of virgin material is used.
More favorable results can be obtained by using recycled PTFE powder instead of powder. Recycled PTFE powder is a powder obtained by baking the virgin material once and then pulverizing it, so that the melt viscosity of the resin composition can be significantly increased as when PTFE of the virgin material is added to the resin composition. And does not impair injection moldability. Also,
Recycled PTFE powder is an additive that, once fired, can provide a stable molded product without any dimensional change, shape change or cracking of a resin molded product mixed with the PTFE powder.

The PTFE resin, which is the raw material of the recycled PTFE powder, has a structure in which the carbon atoms constituting the molecular chain serving as the skeleton are all surrounded by fluorine atoms. It has the highest heat resistance among resins, and is excellent in various properties such as coefficient of friction, non-adhesion and chemical resistance. The thermal decomposition temperature of the PTFE resin is about 5
08 to 538 ° C. Commercial products of the above-mentioned recycled PTFE powder include, for example, KT300M, KT manufactured by Kitamura Corporation.
300H, KT400M, KT400H, KTL610
and so on.

In addition, the above-mentioned graphite is scaly,
Any shape such as spherical, natural graphite,
Artificial graphite may be used, and scaly natural graphite is excellent in slidability, price, and the like. The graphite has a fixed carbon amount of, for example, 90% or more, preferably 95% or more.
% Or more, more preferably 97% or more and 100% or less, a seal ring containing the same is preferable in terms of abrasion resistance, shrinkage of a molded article due to a heat treatment step such as crystallization, and the like. .

The molybdenum compound may be any compound containing molybdenum. In addition to the typical molybdenum disulfide (MoS ₂ ), molybdenum selenide, molybdenum oxide (MoO ₃ ), and dimolybdenum nitride (MoS)
₂ N), calcium molybdate (CaMoO _4, Ca
₃ MoO ₆ ), molybdenum bronze (Na _X MoO ₃ :
Here, 0 <x ≦ 1) and the like.

The tungsten compound may be any compound containing tungsten. In addition to tungsten disulfide (WS ₂ ), tungsten selenide, tungsten oxide (WO ₃ ), ditungsten nitride (W ₂ N), calcium tungstate (CaWO ₄ , Ca ₃ W
O ₆ ), tungsten bronze (Na _X WO ₃ : here, 0 <x ≦ 1) and the like.

Among these compounds, perfluorofluorinated compounds and sulfide compounds, and those having a fixed carbon amount of 97 to 1
It is considered that 00% graphite is preferable in terms of heat resistance, slidability and the like because it is stable in molecular structure.

The method of forming the seal ring is not particularly limited, and various additives such as fibrous and granular materials in the above resin composition are blended in a mixer such as a tumbler mixer and a Henschel mixer and dry-mixed. , Compression molding, injection molding, extrusion molding and the like. In order to injection-mold a seal ring having good dimensional accuracy, it is preferable to melt-mix the resin composition to produce a granulated body, and then subject the granulated body to injection molding.

In injection molding, a seal ring having a complicated shape as shown in FIGS. 1 and 2 can be easily and efficiently produced, and the seal ring can be manufactured at low cost. Molded products are
With the abutment closed, for example, 80-380 ° C, PEE
When the K material is subjected to a heat treatment for about 1 to 24 hours at a temperature of not less than the glass transition point of the resin material and less than the melting point, such as 140 to 320 ° C., dimensions when used at a high temperature are stabilized.

The shape of the abutment portion of the seal ring can be any shape as long as the sealing property is not impaired.
For example, an abutment 11 having a complicated cut shape as shown in FIGS. 1 and 2 or a straight cut 1 as shown in FIG.
It may be 2. Other well-known shapes such as angle cut and step cut may be used. In this way, the seal ring having the abutting portion can be easily incorporated into the shaft (that is, the shaft groove 10) in a state where the abutting portion is expanded so as to be twisted.

As shown in FIG.
Is relatively easy and efficient when providing the notch, so that the productivity is excellent. On the other hand, the abutment 11 having a step cut or a complicated cut shape is excellent in the sealing property of the seal, and the angle cut has an intermediate characteristic between these two. The seal ring according to the present invention may be an endless type having no abutment portion depending on specifications.

FIGS. 2 (a), 2 (b) and 2 (c) show the abutments 11 and 11 'having one of the composite step cut types. The abutments 11 and 11 ′ are composed of the outer diameter side projection 12 and the outer diameter side step 17, and the outer diameter side projection 12 and the outer diameter side step 17 of both the abutments 11 and 11 ′ are formed. Diameter side step 17
And the outer diameter surface side projection 12 are fitted complementarily at a constant gap.

The relationship between the outer diameter side projection 12 and the outer diameter side step 17 is such that if at least one portion has such a shape, the sealing performance is improved. It is preferable that the opening has a shape having a pair of projections and a stepped portion so that the seal ring can be efficiently assembled. The details are as follows.

With respect to one of the abutments 11, a portion where the outer diameter side projection 12 protrudes in the circumferential direction from the ring main body and a portion where the recess forming the outer diameter side step 17 extends in the opposite direction are formed on the inner diameter side. When this surface is referred to as the butting surface 20 with the front end surface as a reference, the outer diameter surface side projection 12 has one side surface when the butting surface 20 is divided into two right and left sides.
In addition, the outer diameter surface 21 of the outer diameter surface side projection 12 is provided on the outer diameter side when it is divided into two inside and outside (the inner diameter side and the outer diameter side of the ring main body 9), and is continuous with the outer surface of the ring main body without a step. It is formed to have the same curvature. Strictly speaking, the abutting portion may be considered to indicate the central portion 16 between the butting surfaces 20, but it is not necessary to specify only this portion as the abutting portion.

The outer diameter side step 17 is provided on the other side and outer diameter when the abutment surface 20 is similarly divided into right and left and inside and outside, and the outer diameter side step 17 is provided. Inner surface 22 is formed to have the same curvature as the inner diameter surface of the ring body.

The other contact 11 ′ is the same as the contact 11
Are formed in a form complementary to
Are fitted to each other with a certain gap, and the seal ring is substantially circular. Such a seal ring having an abutment shape can significantly reduce the amount of leakage and also has good incorporation.

The abutments 11, 11 'may be provided with chamfers or fillets as desired. The chamfered portion may have an arc shape having a predetermined curvature (also referred to as a radius), but may have a curvature of 0, that is, a chamfered shape due to a slope (also referred to as a chamfer). Such a chamfered portion can have, for example, a shape in which the curvature continuously changes in various ways. By providing chamfers and fillets,
Since the amount of protrusion between 1, 1 'or between the abutment and the mating material becomes zero or less, local contact can be prevented.

The following are examples of chamfers and fillets that can be provided at the abutments 11 and 11 '. A chamfered portion 13 is formed at the boundary between the distal end surface 19 of each outer diameter side projection 12 and the outer diameter surface 21, and a chamfer is formed between the step surface 18 of each outer diameter side step 17 and the outer diameter surface 21 of the ring body. A portion 13 ′, a chamfered portion 14 at a boundary between each outer diameter side projection 12 and the distal end face 19 and the inner side surface 23 of the outer diameter side projection 12, a tip end face 19 and an outer diameter side of each outer diameter side projection 12. A chamfered portion 14 ′ at the boundary with the inner diameter side surface 26 of the projection 12, an inner surface 22 of each outer diameter side step 17,
A chamfered portion 14 ″ is formed at the boundary with the abutting surface 20, the step surface 18 of each outer diameter side step 17 and the inner side surface 2 of the outer diameter side projection 12.
3 or the outer diameter side step 17 at the boundary with 3
A round fillet 15 can be provided at the boundary between the step surface 18 and the inner surface 22 on the outer diameter side. Note that corners other than the above-described corners may be formed into a chamfered shape or a shape obtained by adding a fillet.

Further, in order to prevent contact between the abutments 11 and 11 ', the inner diameter side surface 26 of the outer diameter surface side projection 12 and the outer diameter side cut portion of the other abutment 11' or 11 facing the same. it can be provided a predetermined gap g ₁ between the inner surface 22 of 17. By doing so, the amount by which the outer diameter side projection 12 protrudes toward the outer diameter side of the seal ring is further reduced. The dimensional tolerance of the thickness direction of the outer diameter surface side projection 12 and the outer surface side step 17 can also be absorbed by the gap g _1,
Each of the outer diameter side projections 12 is prevented from protruding toward the outer diameter side.

[0075] It is also possible to also between the inner surface 23 mutually facing each other of each of the outer diameter surface side projections 12 of both abutments 11, 11 'is provided a predetermined gap g _2. This gap g ₂
Absorbs the dimensional tolerance in the width direction of each of the outer diameter side projections 12 and prevents each of the outer diameter side projections 12 from projecting to both side surfaces.

The shape of the chamfered portion or the fillet portion may be either a curvature or a slope, but a more preferable shape is a chamfered shape having a curvature. The dimension near the minimum value of the chamfered portion or the fillet portion is about 5% to 50%, preferably about 5% to 25% of either the axial dimension or the radial dimension of the rectangular cross section of the seal ring.
%, More preferably 5 to 15%. If this value is too small, it is considered that the mating member is damaged when the amount of protrusion of the abutting portion is small.

On the other hand, the dimension near the maximum value of the curvature or the shape of the chamfered portion or the fillet portion of the slope is approximately one of the outer diameter of the seal ring, the inner diameter, or the diameter of the intermediate portion thereof. About 50%, preferably about 2 to 15%
Degree, more preferably 3 to 12%. If this value is too large, the effect of providing a chamfered part is weakened,
Only a chamfer substantially equal to the curvature of the outer diameter of the seal ring can be formed, and it cannot be expected that the amount of protrusion at the abutment portion will be zero or reduced. In any case, the chamfer dimensions are above or above these minimums,
The range may be less than or less than these maximum values.

The gaps g ₁ and g ₂ correspond to at least one of the width of the rectangular cross section of the seal ring and the thickness of the side wall.
If it is about 20%, preferably about 3% to 10%, it is possible to absorb the respective dimensional tolerances of the abutment portion while maintaining the sealing property. In particular, it does not decrease sealability even be a clearance g _1. These curvatures, chamfers, and gaps may be formed by an injection molding die or may be formed by tumbling (polishing).

Further, the gate position is a portion other than the position 180 ° from the mouth of the seal ring, for example, a range of 0 or more from the mouth or ± 179 ° or less from 0, preferably ± 179 ° from the mouth. 5 ° or more, ± 175 ° or less, more preferably ± 30 ° or more, if it is a seal ring provided with a gate at a position of ± 170 ° or less, when the ring is expanded and assembled into the shaft groove, Opposing part (180
°) Even if stress concentrates on the part, the ring is hard to break.

If the surface roughness (arithmetic mean roughness) of the surface of the seal ring in contact with the mating member is 0.1 to 2.5 μmRa, the seal ring slides on at least one surface of the mating shaft or the mating cylinder. Is also preferred because it is hard to damage either the ring itself or the mating member. From such a tendency, the surface roughness is preferably 0.2 to 2.0 μm Ra, particularly 0.3 to 1.3 μm Ra on the outer diameter surface of the ring, and 0.7 on the side surface of the ring.
It is preferable to set the thickness to 2.3 μmRa.

The seal ring obtained by the above method has a heat resistance that can withstand a normal use temperature of 40 ° C. or more at a fluid pressure of 1 to 20 MPa (preferably 2 to 10 MPa, and further 3 to 6 MPa depending on specifications and conditions). Instantaneous maximum temperature about 180
It is mounted on a CVT or the like that requires heat resistance to withstand about ℃, specifically, heat resistance that does not melt at a continuous use temperature of 80 to 160 ° C., and can seal oil at relatively rotating parts. Also, such an oil seal ring is, of course, an ordinary device having a fluid pressure of less than 3 MPa,
For example, it can be effectively used in an automatic transmission (AT) device having a fluid pressure of 1 to 2 MPa.

Further, the mating material such as the shaft (piston) and the cylinder is made of carbon-containing steel such as S15C, S45C, SCM420H, spheroidal graphite cast iron such as FCD45, other carbon-containing metal, or a hardened material thereof or other hard material. It may be a material or an aluminum alloy such as ADC12 or other soft material. Such partner material,
A cast metal that is excellent in terms of productivity such as processing efficiency, price, and the like, or an ADC-based light-weight cast metal alloy may be used depending on specifications and conditions.

[0083]

EXAMPLES Examples 1 to 6 and Comparative Examples 1 to 4 The following materials were mixed according to the amounts shown in Table 1 to form oil seal rings. The size of the oil seal ring is φ
20mm (outer diameter) x φ16.4mm (inner diameter) x 2.0m
m (width), and the ratio of the scale of the ring outer diameter to the thickness and width of the ring is 1.8 (mm) / 20 (mm) to 2 (mm).
/ 20 (mm), that is, 9/100 to 10/100. The developed length from the tip surface 19 of the seal ring to the other tip surface 19 is 68 mm.

In the case of Examples 1 to 6 and Comparative Examples 1 to 3, the shape of the abutment is a complicated cut shape as shown in FIGS. 1 and 2, and in the case of Comparative Example 4, , A straight cut 27. The gate position was provided at a position 170 ° from the opening of the ring (indicated by an arrow in FIG. 1).

In Examples 1 to 6 and Comparative Examples 1 to 3, the following materials were melt-mixed and granulated, and the obtained granules such as pellets were injection-molded. After that, the sealing ring was fixed with a jig in a state where the joint portion was closed, and heat treatment was performed at 200 ° C. for 2 hours. For Comparative Example 4, a molding method by compression molding, firing, and then machining was employed.

In the corners in FIG. 2, the corners 13 are R2m.
m, the corner portion 14 'R0.2mm, gap g ₁ is 0.1mm
Is formed by an injection molding die, and then tumbling is performed to remove burrs at each corner.
It was set to 1 mm or less. The surface roughness of the seal ring is
According to the evaluation of the arithmetic average roughness (Ra), 0.5 to 1.0 μm on the outer diameter surface of the ring, and 0.8 to 2.0 μm on the side surface of the ring.
It was 0 μm.

PEEK (polyether ether ketone) manufactured by Mitsui Toatsu Chemicals, Inc .: VICTREX-PEEK1
50P (melting point: 334-337 ° C., maximum crystallinity: 48)
%) Carbon fiber (pitch type) Kureha Chemical Co., Ltd .: Crecachop M107T (tensile strength: 590 to 790 MPa, tensile modulus: 30 to 33 GPa, average fiber diameter: 18 μm) Carbon fiber (PAN type) Toray Industries: MLD100 ( Tensile strength: 2450-7060 MPa, tensile modulus: 20
0-500 GPa, average fiber diameter: 7-8 μm) Recycled PTFE: KTL610 (average particle size: 3-20 μm [scanning electron microscope]) Scale natural graphite Nippon Graphite: ACP (fixed carbon amount: 99.5) %) Molybdenum disulfide manufactured by Dow Corning: Molycoat Z powder.

Using the obtained seal ring, a durability test was performed under the following conditions to measure the wear of the ring and the mating material, and further examined the incorporation into a shaft. The hydraulic conditions in the durability test conditions corresponded to the actual use conditions in a continuously variable transmission for automobiles. These results are summarized in Table 1. ◎, 、, and × in Table 1 indicate the following. ◎ Easy to install ○ Not easy but easy to install without damage × Endurance test conditions broken and unable to be installed Hydraulic pressure 5MPa Shaft rotation speed 4000rpm Oil temperature 120 ° C Time 24 hours Oil used Showa Shell Sekiyu KK: Dexilon II Counterpart cylinder S15C shaft S45C

[0089]

[Table 1]

As is evident from the results in Table 1, there is no problem in any of the ring wear amount, the wear amount of the counterpart material, and the wear amount of the counterpart material in all of Examples 1 to 6. Further, in Example 3, since carbon fiber was blended at 40% by weight, it was more rigid than the other examples, and the assembling property was slightly lowered, but the wear resistance of the ring was good.

On the other hand, in Comparative Example 1, since a large amount of PAN-based carbon fibers having special properties were mixed in the molded article, the wear resistance of the ring itself was poor. Comparative Example 2
Means that the blending amount of the pitch-based carbon fiber is less than a predetermined amount.
Since the content is about% by weight, the ring has poor wear resistance. In Comparative Example 3, the blending amount of the pitch-based carbon fiber was 50% by weight, which was larger than the predetermined amount. The amount of wear of the ring and the amount of wear of the counterpart were appropriate and there was no problem. Poor sex. Comparative Example 4 is inferior in creep resistance and is reinforced with PTFE as a main component not containing an aromatic ring with pitch-based carbon fibers, but is inferior in wear resistance of the ring itself.

[0092]

As described above, according to the present invention, since the seal ring is formed of a composition comprising at least two or three components, the sealing performance is improved under high oil pressure conditions. In addition, there is an advantage in that the seal ring has good sliding characteristics and is easily assembled into a shaft or the like, such as an oil seal ring.

[Brief description of the drawings]

FIG. 1 is a front view of a seal ring according to a first embodiment.

FIG. 2A is an enlarged front view showing an abutment portion of the first embodiment; FIG. 2B is a plan view of the same; FIG.

FIG. 3 is a front view of a seal ring according to a second embodiment.

FIG. 4 is a sectional view showing an example of a structure of a continuously variable transmission.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Driven shaft 2 Fixed pulley 3 Movable pulley 4 Hydraulic clutch 5 Hydraulic chamber 6 Hydraulic chamber 7 Hydraulic passage 8 Hydraulic passage 9 Oil seal ring 10 Shaft groove 11, 11 'Abutment 12 Outer diameter side projection 13, 13' Chamfer Part 14, 14 ', 14 "Chamfered part 15, 15' Fillet 16 Center part of abutment 17 Outer surface side step 18 Step surface 19 Tip surface 20 Butt surface 21 Ring outer diameter surface 22 Outer surface side inner surface 23 Inner side surface on outer diameter side projection 24 Ring side surface 25 Stepped portion 26 Outer diameter side projection inner diameter side surface 27 Straight cut

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location F16J 9/28 F16J 9/28

Claims (8)

[Claims] 1. A synthetic resin seal ring for high-pressure fluid sealing comprising a resin composition containing 85 to 60% by weight of a heat-resistant resin and 15 to 40% by weight of an additive. 2. A composition comprising 1 to 20 parts by weight of a lubricity-imparting agent added to 100 parts by weight of a resin composition containing 85 to 60% by weight of a heat-resistant resin and 15 to 40% by weight of an additive. Synthetic resin seal ring for high pressure fluid sealing. 3. A synthetic resin seal ring comprising a resin composition containing 85 to 60% by weight of a heat-resistant resin and 15 to 40% by weight of a fibrous reinforcing material and having an outer diameter of 10 to 30 mm. 4. A resin composition 100 containing 85 to 60% by weight of a heat-resistant resin and 15 to 40% by weight of a fibrous reinforcing material.
A lubricant-containing resin composition in which a lubricity-imparting agent is added in an amount of 1 to 20 parts by weight with respect to parts by weight, the outer diameter of which is 10 to 3
0 mm synthetic ring made of synthetic resin. 5. The fibrous reinforcing material has a fiber length of 0.01 to 0.01.
The synthetic resin seal ring according to claim 3 or 4, having a fiber diameter of 1 mm and a fiber diameter of 1 to 25 µm. 6. The fibrous reinforcing material has a tensile strength of 490.
The synthetic resin seal ring according to any one of claims 3 to 5, wherein the pressure is from 980 MPa to 980 MPa. 7. The synthetic resin seal ring according to claim 3, wherein the heat-resistant resin is an aromatic polyether ketone resin, and the fibrous reinforcing material is carbon fiber. 8. The synthetic resin seal ring according to claim 3, wherein the fibrous reinforcing material is a pitch-based carbon fiber.