JP2003120821A - Seal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the sealability by making the seal bearing pressure of a seal lip sharp, and to prevent the seal lip from being abnormally deformed in inserting a shaft. SOLUTION: An inner diameter of a seal part face 5A is smaller than an outer peripheral diameter of the shaft, an expansion taper face 4 is expanded by an outer diameter of an inclined supporting part 12 of a supporting ring 10, the inner diameter of the seal part face 5A is also expanded, and a seal corner part 5A3 has a dimension capable of being closely abutted on the shaft.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal device having a seal lip for sealing a shaft. More specifically, the present invention relates to a sealing device that allows a sealed fluid such as a high-pressure refrigerant to have a pressure resistance and can be sealed by a seal lip, and easily design a surface pressure excellent in sealing a surface of a seal portion.

[0002]

2. Description of the Related Art Prior art 1 relating to the sealing device of the present invention
There is a lip-type seal disclosed in Japanese Utility Model Laid-Open No. 3-41264. FIG. 7 is a half sectional view of the lip type seal 100 disclosed in this publication. This seal type lip 100 is a lip type seal for a car cooler compressor. For this reason, it is considered to seal the sealed fluid that has been changed from Freon gas to carbon dioxide gas in consideration of the influence on the environment. For this reason, the lip type seal 100 is configured as shown in FIG. In FIG. 7, the sealing surface 1 is in close contact with the outer peripheral surface of the rotary shaft 113 at the end portion 104 in which the seal lip 101 inclines toward the sealed fluid side from the base portion 102 in which the reinforcing ring 103 is embedded.
04a is provided. A garter spring 105 for pressing the sealing surface 104a is mounted in an annular groove provided on the outer peripheral surface of the end portion 104. This garter spring 10
It is necessary to accurately set the axial position dimension of the seal surface 104a with respect to the annular groove in which the 5 is mounted.

An annular backup plate 106 made of a metallic material is lightly fitted into the inner peripheral surface of the seal lip 101 between the inner peripheral surface of the seal lip 101 on the atmosphere side and the rotary shaft 113. It is arranged in a state. Furthermore,
On the atmosphere side of the backup plate 106, an annular lip portion 107 made of a resin material is arranged in the same shape as the backup plate 106. A ring-shaped support plate 109 is arranged on the atmosphere side of the lip 107. The outer periphery of the backup plate 106, the annular lip portion 107, and the support plate 109 is held by a holding ring 110 having a U-shaped cross section.
The entire sandwiched three parts are a seal part and assist the seal lip 101 arranged in parallel.

The seal portion is arranged in parallel with the seal lip 101 and supports the seal lip 101 so as to doubly seal against the pressure of the fluid to be sealed. For this reason, the seal portion is separated from the seal lip 101 and arranged in parallel, and the backup plate 106 supports the seal lip 101. Therefore, if the combination of the two is not accurate, the surface pressure of the seal surface 104a will be reduced. However, it becomes difficult to join them so that the sealing ability can be exhibited. Further, since the seal lip 101 and the seal portion are separated from each other, it is expensive to manufacture each of them. Also, the assembling of these both requires high precision, and thus the cost becomes high.

Also, the distance between the sealing surface 104a at the tip of the seal lip 101 and the annular groove must be accurately manufactured. However, since the seal lip 101 is made of a rubber material, it is easily deformed. It is difficult to secure the distance dimension. Further, the backup ring 106
The seal lip 101 and the seal lip 101 must also be joined accurately. When the backup ring 106 is pressed against the seal lip 101, the seal lip 101 floats up from the outer peripheral surface of the rotating shaft, which deteriorates the sealing ability.

[0006] Still another prior art 2, Japanese Patent Laid-Open No. 2000-2000
No. 179702 exists. The shaft sealing device 200 described in this publication is configured as shown in FIG. FIG. 8 is a half sectional view of the shaft sealing device 200. Shaft sealing device 2
00 is used for a compressor of an automobile, and a sealed fluid of the compressor is carbon dioxide gas. The overall structure is almost the same as that of the conventional technique 1, but the backup ring has different purposes, and the conventional technique 2 has the seal lip 201 and the seal portion 208 in order to prevent the permeation of the sealed fluid. An integrated version of and is disclosed. In this shaft sealing device 200, a tubular seal lip 201 is formed from a fitting portion 202 provided with a wavy seal portion 207 on the outer circumference. Also, the seal lip 20
A seal portion 208 made of a resin material is provided on the atmosphere side of 1. A thin metal plate 206 is disposed between the rubber seal lip 201 and the resin seal portion 208. Since the carbon dioxide gas easily permeates through the rubber seal lip 201, the metal thin plate 206
Is intended to prevent the permeation of carbon dioxide. For this reason, the thin metal plate 206 has the seal lip 201.
And the seal portion 208 are interposed so as to be attached to the entire surface of the seal lip on the atmosphere side.

However, it is structurally difficult and structurally difficult to support the thin metal backup ring 206 so that the seal lip 201 is always in close contact with the rotary shaft 213. In other words, it is difficult to expand the seal portion 204a of the seal lip 201 by the backup ring 206 so that the seal portion 204a of the seal lip 201 is strongly pressed against the rotating shaft 213 by the elastic force. This is because when the seal lip is stretched and expanded, the gas can easily permeate quickly. Further, it is difficult for the backup ring 206 to prevent the seal portion 204a from being pressed by the pressure of the sealed fluid to come into pressure contact with the rotating shaft 213. Furthermore, since the backup ring 206 is made of a thin metal, it is difficult to expand and hold the seal portion 204a of the seal lip 206 so as to optimally press the rotary shaft 213.

[0008]

In the prior art as described above, when the seal device is fitted into the shaft, the inner diameter of the seal portion of the seal lip is in close contact with the outer diameter of the shaft. If this close contact is too strong, or conversely too weak, a sharp surface pressure cannot be formed, and the sealed fluid will leak. For this reason, it is attempted to insert and join the inner diameter of the seal portion so that the inner diameter of the seal portion becomes the optimum inner diameter. However, to expand the seal part of the rubber seal lip and press fit the shaft,
It is difficult because the friction resistance of rubber is large. For this reason, the seal portion is extended in the insertion direction of the shaft due to the frictional resistance, and the seal surface is always improperly fitted to the shaft. Then, in the fitted state in which the facing angle of the seal portion with the shaft circumferential surface is small and deformed, sealing is performed in a state of widely contacting the shaft. In this fitted state, since the contact area with the shaft peripheral surface becomes large, a sharp surface pressure is not formed and the sealing ability is deteriorated. As a result, the sealed fluid is leaked.

Further, when the seal portion is strongly pressed against the shaft, the contact area increases, the surface pressure becomes gentle and the sealing ability deteriorates, and due to friction of the seal surface, sludge is generated on the seal surface to cause wear. It will be promoted. As a result, the sealing ability is reduced. Furthermore, when the pressure of the sealed fluid becomes high in the above-mentioned state, friction with the shaft peripheral surface of the seal portion increases, and wear of the seal surface is promoted.

The present invention has been made in view of the above problems, and a technical problem to be solved by the present invention is that even if a shaft is inserted into a seal portion of a sealing device, the seal portion is not attached to the shaft. And in close contact with sharp surface pressure.
Another object is to bring the seal portion into close contact with the shaft in a state of sharp surface pressure to improve the sealing ability. At the same time, even if the seal part receives pressure from the sealed fluid, the seal part is held so as not to have a large contact area with the peripheral surface of the shaft to prevent wear of the seal part. Further, it is another object of the present invention to facilitate the design of the surfaces of these seal portions by a simple combination of structures.

[0011]

The present invention has been made to solve the above-mentioned technical problem, and the technical solution is configured as follows.

The sealing device of the present invention according to claim 1 is
A sealing device for sealing between a housing having a fitting hole and a shaft fitted in the fitting hole of the housing, wherein a fitting portion that is hermetically fitted in the fitting hole of the housing is tubularly sealed. A seal lip made of a rubber-like elastic material, which has an expanded taper surface that is formed inward and extends to the shaft on the fluid side, and has a seal corner portion that makes a sealing contact with the shaft peripheral surface at the tip of the expanded taper surface, A support ring made of a harder material than the rubber-like elastic material, having one end held by the fitting portion, extending in a tubular shape along the inner circumference of the seal lip, and having an inclined support portion that fits with the expanded tapered surface; And an inclination angle of the expanded tapered surface with respect to the axial peripheral surface is formed at an angle larger than an inclination angle of the inclined support portion with respect to the axial peripheral surface, and the inclined support portion is fitted to the expanded tapered surface. The angle of inclination of the expanded tapered surface is Those that are elastically deformed to the angle of the inclined support portion.

In the sealing device of the present invention according to claim 1, the inclined support portion of the support ring is press-fitted into the expanded tapered surface of the seal lip to expand the diameter of the seal portion surface, and further, the inclined support is provided. Since the expanded taper surface inclined at the portion is held in pressure contact, the atmosphere side seal portion surface can be held at a constant angle. Further, the held seal surface of the seal portion can be brought into close contact with the outer peripheral surface of the shaft with a sharp surface pressure, so that the seal of the seal portion surface is surely exhibited. At the same time, since the seal part surface is configured to contact the shaft with a small contact area, even if the seal device is inserted into the shaft, the seal part surface does not extend in the shaft inserting direction by the shaft, and the seal part It effectively prevents the sealing ability from deteriorating due to abnormal deformation when the surface is pushed in, and keeps the sealing corners in contact with each other with a sharp surface pressure to exert excellent sealing ability. Further, since the surface of the seal portion is expanded by the inclined support portion of the support ring and is in contact with a sharp surface pressure due to the optimum interference state, even if a high pressure sealed fluid acts on the seal lip, the seal portion The surface is prevented from coming into contact with the peripheral surface of the shaft so as to increase the area. For this reason, the frictional resistance of the surface of the seal portion is small, and it is possible to prevent wear due to the friction.

The sealing device of the present invention according to claim 2 is
The inclination angle of the inclined support portion of the support ring is 4 ° to 8 ° from the inclination angle of the expanded tapered surface of the original shape of the seal lip.
It is formed small in the range of.

In the sealing device of the present invention according to claim 2, when the atmosphere side seal portion surface of the seal ring is formed smaller by the same angle of 4 ° to 8 ° by the inclined support portion of the support ring, the seal portion is formed. Since the surface is held under the tension so that the surface pressure becomes the sharpest, the sealing ability is exhibited in the optimum close contact state. The angle of the atmosphere side seal part surface is 4 °.
Since the acute angle is in the range of 8 °, the shaft can be easily inserted, and the sealing ability is exhibited without the sealing corners coming into close contact in the deformed state due to the shaft insertion. Further, the atmosphere side seal portion surface has a diameter increased by the inclined support portion through the expanded taper surface, and the seal corner portion has a tight margin with the shaft outer peripheral surface to closely adhere to each other to exert a sealing effect. Even if is subjected to the pressure of the fluid to be sealed, the seal part surface is in a tight state, so
A large area is prevented from coming into contact with the outer peripheral surface of the shaft. For this reason, the seal portion surface has a small frictional resistance, and wear is prevented for a long period of time.

The sealing device of the present invention according to claim 3 is
0.8 mm to 2.0 mm from the outer diameter of the shaft in a state where the seal part surface of the seal lip is expanded by the inclined support part.
They are fitted with a tight margin formed to a small diameter of mm.

In the sealing device of the present invention according to claim 3,
With the expanded taper surface of the seal lip expanded by the inclined support part, the seal part surface is configured to fit on the shaft with a tightening margin of 0.8 mm to 2.0 mm. The corners make sealing contact with the shaft peripheral surface with sharp surface pressure, and the sealing performance is improved. Further, the sliding resistance of the seal surface is small in the range of the tightening margin of the seal corner portion, and the wear of the seal surface can be prevented for a long period of time.

The seal device of the present invention according to claim 4 is
The axial length of the inclined support surface of the support ring is 0.3 to 0.66 relative to the axial length of the taper surface of the seal lip.
It is formed in the length of the ratio.

In the sealing device of the present invention according to claim 4, the length of the inclined support portion of the support ring is 0.3 to 0.66 with respect to the length of the expanded taper surface of the seal lip. Since it is press-fitted in at, the sealing part is stably held at a constant inclination angle without the tip of the inclined support part coming into contact with the shaft because it is too long. The surface pressure can be formed by the portion to exert the sealing ability. Further, since the inclined support portion can support up to the vicinity of the seal corner portion, it is possible to prevent a pressure contact state in which the seal corner portion is pressed against the shaft against a high pressure from the fluid to be sealed and improve the sealing ability. .

The sealing device of the present invention according to claim 5 is
The support ring is made of a resin material and has a support ring which is formed on the inner surface of the end portion of the inclined support portion so as to be close to or slidably fitted to the shaft.

In the sealing device of the present invention according to claim 5, since the support ring is made of a resin material, the frictional resistance is small even when it slides on the shaft, and the support ring can be supported by the shaft. Narui. Further, the inclined support portion can be lengthened to support up to the vicinity of the seal portion surface. As a result, even if the high pressure of the sealed fluid is received, the seal portion surface is effectively prevented from being pressed against the shaft, and the sealing effect is exhibited even with the high pressure sealed fluid. Furthermore, when a support ring made of a resin material is joined to a seal ring made of a rubber material to exert elastic composite characteristics, it is possible to exert the sealing ability of the seal portion surface with respect to the shaft.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION A seal device according to a preferred embodiment of the present invention will be described in detail below with reference to the drawings. Each drawing described below is not a so-called patent conceptual drawing, but a design drawing having accurate dimensional relationships.

FIG. 1 shows a sealing device according to a first embodiment of the present invention, and is a half cross-sectional view of the sealing device not mounted on a shaft. 2 is a cross-sectional view showing a main part which is a seal part in a state where a shaft is mounted on the seal device 1 in FIG. In FIG. 1, reference numeral 1 is a sealing device. The sealing device 1 is provided with a rubber-made fitting portion 7 that is fitted into the fitting hole 61 of the housing 60. A convex-shaped seal portion 7A is formed on the outer peripheral surface of the fitting portion 7. A reinforcement ring 8 is embedded in the fitting portion 7. The reinforcement ring 8 strengthens the fitting with the housing 60, and the fitting portion 7 has a second seal lip 15 and a back plate ring 20. It holds joint parts such as.

A seal lip 3 made of a rubber material is formed in a tubular shape inclined from the fitting portion 7 toward the rotary shaft 50 via the reinforcing ring 8. A seal portion 5 is formed at the inner end of the seal lip 3, and the inner surface of the seal portion 5 is formed as a seal portion surface 5A. The seal section surface 5A forms a seal corner section 5A3 having a triangular cross section, and both sides of the seal corner section 5A3 are formed as an atmosphere side seal section surface 5A1 and a sealed fluid side seal section surface 5A2. The sealing corner portion 5A3 forms a sealing function surface, and when the sealing corner portion 5A3 comes into close contact with the rotary shaft 50 optimally, the surface pressure is increased to exert the sealing ability. Further, at the base of the seal portion 5 of the seal lip 3, an expanded taper surface 4 is formed which is continuous with the atmosphere side seal portion surface 5A1 which is smoothly bent from the inner surface of the cylinder and inclined.

A support ring 10 made of a resin material and having substantially the same shape as the seal lip 3 is provided along the surface of the seal lip 3 from the fitting portion 7 of the seal lip 3 to the side of the expanded taper surface 4. The outer peripheral holding portion 11 of the support ring 10 is sandwiched by the fitting portion 7. Further, the inner peripheral end of the support ring 10 is formed in an inclined support portion 12. The inclined support portion 12 is formed in a tapered surface so as to be press-fitted to the expanded tapered surface 4 of the seal lip 3. There is. By pressing the inclined support portion 12 into the expanded taper surface 4, the seal portion surface 5A is formed.
Are enlarged by a predetermined size. or,
The inner end of the support ring 10 is formed in the ring portion 13. On the inner end surface 14 of the ring portion 13, the rotating shaft 50
It is formed with an inner diameter in the range where it does not come into contact with. The support ring 10 is formed by resin molding so that one end thereof has a flange shape and the middle portion has a cylindrical shape. The support ring 10 is formed to have a pressure-resistant thickness that does not deform even if the seal lip 3 receives the pressure of the sealed fluid.

Further, a second lip seal 15 made of a resin material is provided on the inner peripheral surface of the support ring 10 on the atmosphere side. The second seal lip 15 has a ring-shaped holding portion 16 whose outer circumference is in the radial direction, and an inner circumference of which is a lip portion 17 which is inclined from the holding portion 16. Then, the inner end side of the lip portion 17 is press-fitted into the rotary shaft 50 to form a tubular shape, and seals the rotary shaft 50.

Further, an outer peripheral support portion 11 of the support ring 10,
A back plate ring 20 that supports the holding portion 16 of the second seal lip 15 from the atmosphere side is provided. The back plate ring 20 is made of metal and has an inner end formed in a curved portion so as to support the bent portion of the second seal lip 15.

The outer peripheral support portion 11 of the support ring 10 and the second
The sandwiching portion 16 of the seal lip 15 and the back plate ring 20 are sandwiched by the fitting portion 7 so as to be crimped by the reinforcing ring 8. The reinforcing ring 8 is covered with the rubber of the fitting portion 7.

FIG. 2 shows a rotary shaft 50 of the sealing device 1 of FIG.
It is sectional drawing of the principal part in the state which mounted | worn. The seal lip 3A of the phantom line shown in FIG. 2 is an original view, and the expanded inner peripheral surface 4 and the seal portion surface 5A of the seal lip 3 are formed in a small diameter in the original shape so that they can be expanded with respect to the size of the rotating shaft 50. ing. When the inclined support portion 12 of the support ring 10 is press-fitted into the expanded tapered surface 4 of the seal lip 3 to expand the seal portion 5, the seal lip 5 is elastically deformed like the solid seal lip 3 shown in FIG. The expanded tapered surface 4 is press-fitted into the inclined support portion 12 to expand the inner diameter of the seal portion surface 5A from 0.1 mm to 3,
The diameter is expanded from the original shape in the range of up to 2 mm. The diameter expansion of the seal surface 5A is determined according to the diameter of the rotary shaft 50. More preferably, the inner diameter of the seal portion 5A should be expanded in the range of 1 mm to 2.2 mm. Further, the inner diameter of the seal portion surface 5A may be smaller than the diameter of the rotary shaft 50 within the range of 0.6 mm to 2.2 mm. More preferably, the inner diameter of the seal portion surface 5A is small in the range of 0.8 to 1.6 mm.

When the inclined support portion 12 is press-fitted into the expanded tapered surface 4, the axial angle of the atmosphere side seal portion surface 5A1 with respect to the peripheral surface of the rotary shaft 50 becomes smaller than that of the imaginary line which is the original shape. Therefore, the rotation shaft 50 can be easily inserted into the seal portion surface 5A. As a result, the seal portion 5 is not extended in the inserting direction of the rotary shaft 50 by the insertion of the rotary shaft 50 into the seal portion surface 5A, and the sealing corner portion 5A3 is brought into close contact with the rotary shaft 50 to have a sharp surface pressure. Be effective. Furthermore, when the inclined support portion 12 is press-fitted into the expanded taper surface 4, the seal corner portion 5A3 of the seal portion surface 5A is fixed to the rotary shaft 50.
On the other hand, since the diameter is expanded within the dimension in which the tightening margin is provided, the surface pressure of the seal corner portion 5A3 forms a sharp pressure distribution P to exert the sealing ability.

When the support ring 10 is made of a resin material, it is more elastic than that made of a metal material and imparts a composite elasticity to the seal lip 3 made of a rubber material. Is demonstrated. Further, if the support ring 10 is made of a resin material, even if the support ring 10 comes into contact with or slides on the rotary shaft 50, the sliding resistance is small, and therefore the occurrence of wear on the contact surface is prevented. Further, the inner end surface 14 of the support ring 10 can be brought into close proximity or sliding contact with the rotary shaft 50. As a result, the seal portion 5 can be effectively supported by the ring portion 13 of the support ring 10, and the pressure resistance of the seal portion 5 against the high pressure of the sealed fluid can be exhibited.

Furthermore, since the seal portion 5 is tightened by the expanded amount and the vicinity of the seal portion surface 5A1 which is continuous with the expanded taper surface 4 is supported by the inclined support portion 12, it is sealed. Even if the pressure of the fluid strongly acts on the outer peripheral surface of the seal portion 5, the pressure resistance can be exhibited. Furthermore,
For example, since the sealed fluid leaked from the seal lip 3 is sealed by the second seal lip 15, the seal portion surface 5
Since the pressure increases on the atmosphere side of A, the seal portion 5 exhibits pressure resistance against the pressure from the sealed fluid.

FIG. 3 shows a sealing device 1 showing a second embodiment.
FIG. In FIG. 3, the sealing device 1 of FIG.
Is different from the fitting hole 7 in the fitting hole 6 of the housing 60.
1 is sealed via O-ring 25. or,
The support ring 10 is made of a metal material. The support ring 10 is formed into a flange shape at one end and a cylindrical shape at the middle by deep drawing a metal plate. The outer peripheral surface of the inclined support portion 12 of the support ring 10 is formed into a tapered surface, and the ring portion 14 at the inner end extends not near the radial direction but near the seal portion surface 5A1 in a tapered shape. The inclined support portion 12 is press-fitted into the expanded tapered surface 4 of the seal lip 3, and the seal corner portion 5A3 is expanded by the inclined support portion 12. Since the support ring 10 is made of a metal material, the inclined support portion 12 is formed in an inclined simple structure.

FIG. 4 is a half cross-sectional view showing a main part of the sealing device 1 showing the third embodiment of the present invention. 4 is different from the sealing device 1 of FIG. 3 in that a ring portion 13 is provided at the inner end of the inclined support portion 12 of the support ring 10. The seal lip 3 is similar to the other embodiments. The phantom line in FIG. 4 shows the original shape of the seal lip 3A. Further, the solid line is a state diagram in which the expanded tapered surface 4 of the seal lip 3 is expanded by the inclined support portion 12. In FIG. 4, the taper angle θ1 of the atmosphere-side seal portion surface 5A1 and the taper angle θ2 of the inclined support portion 4 are substantially the same, and the taper angle θ0 of the atmosphere-side seal portion surface 5A1 of the phantom line seal lip 3A is θ1. And 3 ° from θ2
It is formed at a large angle of 10 ° from. This 3 ° to 10 ° is the angle to be expanded.

FIG. 5 is a cross-sectional view of essential parts showing a seal lip of the sealing device 1 according to the fourth embodiment. Support ring 10
When the inclined support portion 12 is pressed into the expanded taper surface 4 of the seal lip 3A of the imaginary line, it is elastically deformed into the shape of the seal lip 3 as shown by the solid line. By pressing the support ring 10 into the expanded taper surface 4, the seal corner portion 5A3 of the seal portion surface 5A is also expanded as shown in FIG. 4, so that the contact surface of the seal corner portion 5A3 with respect to the rotating shaft 50 is Pma of 5
The surface pressure distribution P such as x is formed in a sharp shape. This improves the sealing ability. In particular, in the surface pressure distribution P, the shape of the sealed fluid side being sharp indicates that the ability to seal the sealed fluid is excellent. The atmosphere side seal portion surface 5A1 of the seal portion surface 5A is
Since the inclination angle θ1 with respect to the rotation shaft 50 is smaller than that of the imaginary line, the rotation shaft 50 is prevented from being stretched in the insertion direction of the rotation shaft 50 and abnormally deformed. This improves the sealing ability.

Next, when the support ring 10 is made of a resin material, the inner end surface 14 of the ring portion 13 can be fitted or slidably fitted to the rotary shaft 50. Furthermore, in order to facilitate the insertion of the rotary shaft 50 and further to reduce the contact area, the inner end surface 14 may be formed into a tapered surface that converges in the insertion direction. Further, even if the pressure of the sealed fluid becomes high, the ring portion 13 can effectively support the seal portion 5. For example, even if the inner end surface 14 comes into contact with the rotating shaft 50 due to the pressure of the sealed fluid, the inner end surface 14 made of a resin material can have a small sliding resistance and a small contact area. As a result, the seal surface 5A
The pressure resistance against the pressure of the sealed fluid is improved.

FIG. 6 is a half sectional view showing a main part of a sealing device showing a fifth embodiment of the present invention. FIG. 6 is a mounting state diagram of the seal lip 3 mounted on the rotary shaft 50. In the seal lip 3 shown in FIG. 6, the expanded taper surface 4 is formed as a continuous surface at the same angle on the atmosphere side seal surface portion 5A1. Further, the inclined support portion 12 of the support ring 10 is formed in a tapered surface shape, and by pressing the inclined support portion 10 into the expanded tapered surface 4, the seal portion surface 5A can be expanded in diameter with respect to the rotary shaft 50. You can The support ring 10 is made of a metal material, for example, stainless steel, aluminum, steel or the like. If the expanded taper surface 4 is formed in an inclined surface shape so that the entire surface is inclined, it becomes easy to design to arbitrarily set the contact area of the seal corner portion 5A3. By setting the contact area of the seal corner portion 5A3, it becomes possible to form the surface pressure distribution P of the seal corner portion 5A3 as sharp as Pmax. Further, by elastically deforming the angle of the atmosphere side seal portion surface 5A1 to a small angle, it becomes possible to prevent abnormal deformation due to insertion of the rotary shaft 50. Therefore, the sealing ability of the seal portion surface 5A is improved.

[0038]

The sealing device according to the present invention has the following excellent effects.

According to the seal device of the present invention according to claim 1, the inclined support portion of the support ring is press-fitted into the extended tapered surface of the seal lip to expand the seal portion surface, and further, the inclined support portion expands. It is possible to hold the atmosphere-side seal portion surface in contact with the tapered surface at a constant angle. This facilitates the design for exhibiting the sealing effect. further,
The surface of the held seal portion in a tight state can be brought into close contact with the outer peripheral surface of the shaft with a sharp surface pressure. For this reason, the seal surface has an excellent effect. At the same time, since the seal part surface can contact the shaft with a small contact area, even if the seal device is inserted into the shaft, the seal part does not extend in the shaft insertion direction by the shaft, and the seal part surface seals due to abnormal deformation. The ability is effectively prevented from being lowered, and the sealing corner portions are kept in contact with each other with a sharp surface pressure, so that an excellent sealing effect is achieved. Furthermore, since the diameter of this seal portion surface is expanded by the inclined support portion of the support ring and kept in contact with a sharp surface pressure, even if a high-pressure sealed fluid acts on the seal lip, the seal portion surface Does not come into contact with the peripheral surface of the shaft so as to increase the area, so that the frictional resistance of the seal portion surface is small, and the effect of preventing wear due to the friction is exerted.

According to the second aspect of the sealing device of the present invention, in the state in which the atmosphere side seal portion surface of the seal ring is formed at an angle of 4 ° to 8 ° by the inclined support portion of the support ring, the seal portion surface is formed. Since it is maintained with the tensioning force that provides the sharpest surface pressure, the sealing effect is exhibited in the optimum close contact state. Further, by press-fitting the inclined support portion into the expanded taper surface, the angle of the atmosphere side seal portion surface becomes an acute angle, which facilitates insertion of the shaft, and the insertion of the shaft prevents the seal corner portion from coming into close contact in a deformed state. The effect of improving the sealing ability is achieved. Furthermore, since the atmosphere side seal portion surface is expanded by the inclined support portion through the expanded taper surface, the seal corner portion comes into close contact with the shaft outer peripheral surface with a tightening margin, so that the sealing effect is exhibited and the seal is achieved. Even if the part receives the high pressure of the sealed fluid,
Since the seal portion surface is in a tight state, it is prevented from coming into contact with the shaft outer peripheral surface over a large area. Therefore, the seal portion surface has a small frictional resistance, and has an effect of preventing wear for a long period of time.

According to the third aspect of the sealing device of the present invention, in the state where the expanded tapered surface of the seal lip is expanded by the inclined support part, the seal part surface is 0.8 mm to 2.
Since it is configured to be fitted with a tightening margin of 0 mm, the sealing corner portion of the seal portion surface comes into sealing contact with the shaft peripheral surface at a sharp surface pressure, and the sealing performance is improved. Further, the sliding resistance of the seal surface is small in the range of the tightening margin of the seal corner portion, and it is possible to prevent the wear of the seal portion surface.

According to the fourth aspect of the sealing device of the present invention, the length of the inclined support portion of the support ring is 0.3 to 0.66 relative to the length of the expanded tapered surface of the seal lip. Since it is press-fitted in place, it does not become too long and the tip of the tilted support part comes into contact with the shaft, and the seal part is stably held at a constant tilt angle. A sharp surface pressure is formed by the corners, and the sealing ability is exerted. Further, since the expanded taper surface is supported at the same angle by the inclined support surface, the pressure contact state in which the seal corner is pressed against the shaft against the pressure from the sealed fluid is prevented, and the seal against the high pressure of the sealed fluid is prevented. Produce an effect.

According to the sealing device of the fifth aspect of the present invention, since the seal portion surface is supported by the ring portion via the shaft, further, the inclined support portion can be supported up to the vicinity of the seal portion surface. Even when the sealed fluid receives the pressure of the sealed fluid, the seal portion surface is prevented from being pressed against the shaft, and a sealing effect having pressure resistance is exhibited even when the sealed fluid has a high pressure. Further, even if the inner end surface of the support ring is brought close to or in sliding contact with the shaft, since the support ring is made of a resin material, the friction resistance is small and the inclined support portion is close to the atmosphere side seal portion surface. Since it becomes possible to support, the sealing corner portion is optimally supported, and the sealing effect is exerted. Further, the sealing portion made of a rubber material and the inclined support portion made of a resin material have an effect that the sealing ability of the sealing portion surface can be exhibited as a rubber-like elastic force having an elastic composite characteristic.

[Brief description of drawings]

FIG. 1 is a half sectional view before a rotary shaft is attached to a sealing device according to a first embodiment of the present invention.

FIG. 2 is a half cross-sectional view of a main part of a rotary shaft side in a state where a rotary shaft is mounted on the seal device shown in FIG.

FIG. 3 is a half cross-sectional view of a sealing device according to a second embodiment of the present invention with a rotary shaft attached thereto.

FIG. 4 is a half cross-sectional view of a rotary shaft side main portion in a state where a rotary shaft is attached to a sealing device according to a third embodiment of the present invention.

FIG. 5 is a half cross-sectional view of a rotary shaft side main portion in a state where a rotary shaft is attached to a sealing device according to a fourth embodiment of the present invention.

FIG. 6 is a half cross-sectional view of a rotary shaft side main part in a state where a rotary shaft is attached to a sealing device according to a fifth embodiment of the present invention.

FIG. 7 is a half cross-sectional view of a sealing device of Prior Art 1.

FIG. 8 is a half cross-sectional view of a sealing device of Prior Art 2.

[Explanation of symbols]

1 Sealing device 3 seal lip 3A Original seal lip 4 Expanded taper surface 5 Seal part 5A seal surface 5A1 Atmosphere side seal surface 5A2 Sealed fluid side seal surface 5A3 seal corner 7 Fitting part 7A seal part 8 reinforcement ring 10 Support ring 11 Peripheral holding part 12 Inclined support 13 Ring part 14 Inner face 15 Second seal lip 16 clamping part 17 Lip 20 Backboard ring 25 O-ring 50 rotation axis 60 housing 61 Ring hole

Claims (5)

[Claims] 1. A seal device for sealing between a housing having a fitting hole and a shaft fitted in the fitting hole of the housing, the fitting device being sealingly fitted in the fitting hole of the housing. Made of a rubber-like elastic material that has an expanded tapered surface that is formed inwardly and extends in a cylindrical shape toward the shaft on the side of the fluid to be sealed, and that has a sealing corner portion that makes sealing contact with the shaft peripheral surface at the tip of the expanded tapered surface. Harder than the rubber-like elastic material having a seal lip and an inclined support portion, one end of which is held by the fitting portion, extends in a tubular shape along the inner circumference of the seal lip and fits with the expanded tapered surface. A support ring of a material, the inclination angle of the expanded tapered surface with respect to the axial peripheral surface is formed to be larger than the inclination angle of the inclined support portion with respect to the axial peripheral surface, and the inclined support portion is formed on the expanded tapered surface. Of the expanded taper surface The sealing device is elastically deformed so that the inclination angle is substantially equal to the inclination angle of the inclination support portion. 2. The sealing device, wherein the inclination angle of the inclined support portion of the support ring is smaller than the inclination angle of the expanded tapered surface of the original seal lip in the range of 4 ° to 8 °. . 3. The seal lip surface of the seal lip is larger than the outer diameter of the shaft by 0.
The sealing device according to claim 1 or 2, wherein the sealing device is fitted with a tight margin formed to have a small diameter of 8 mm to 2.0 mm. 4. The length of the inclined support portion of the support ring in the axial direction is 0.3 to 0.66 in proportion to the axial length of the expanded tapered surface of the seal lip. The sealing device according to claim 1, 2 or 3, characterized in that. 5. The support ring, which is made of a resin material and has a support ring which is formed on an inner surface of an end portion of the inclined support portion and which is close to or slidably fitted to the shaft. The sealing device according to claim 2, 3 or 4.