JPS5920057B2 - Pressure resistant seal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotary pressure-resistant seal for sealing high-pressure fluid, and more specifically, to prevent the pressure of high-pressure fluid from excessively pressing a sliding lip, This relates to a pressure-resistant seal that has been improved to provide durability with a strong sealing force.

Conventionally, mechanical seals have been widely used as seals for sealing high-pressure fluids.

This kind of device has a complicated structure and is expensive, requires a large space for installation, and has disadvantages such as requiring a large number of man-hours for installation.

Next, a pressure-resistant seal shown in FIG. 1 is known as a pressure-resistant seal that has a simple structure, requires a small installation space, and is easy to install.

FIG. 1 is a half sectional view of the pressure seal.

This is equipped with a pressure-resistant seal in order to seal between the high-pressure side 1 and low-pressure side 2 of the shaft hole 4 through which the rotating shaft 3 passes.The fixing part 9 of the pressure-resistant seal seals the shaft hole 4. The lip portion 7 contacts the shaft 3 and seals it.

The annular spring 6 presses the contact surface of the lip portion γ with the shaft 3 to increase the sealing force.

The dust seal 8 that contacts the shaft 3IF on the low pressure side 2 of this pressure-resistant seal mainly serves to prevent dust from entering from the low pressure side 2.

The metal ring 5 is for reinforcing the structure of the pressure seal.
It has the strength to fit into the shaft hole 4 and the strength to oppose the pressure on the high pressure side 1.

The above configuration has been used as a pressure-resistant seal, but the entire lip portion I is made to have rigidity in order to withstand high pressure.

That is, as a result, the entire lip portion I needs to be thick and hard.

Originally, if the lip portion I that sealsly slides on the shaft 3 is thick and hard, the followability as a sealing property is poor, and there is an inherent problem in sealing performance.

In particular, if the shaft is eccentric, a gap will be created at the contact point between the shaft 3 and the lip portion γ, and the liquid on the high pressure side 1 will flow out.

Further, when the pressure on the high pressure side is high, the lip portion γ is pressed against the shaft 3, the contact force with the shaft 3 becomes high, and the lip portion 7 is worn out due to sliding due to rotation of the shaft 3.

Therefore, the higher the rotation speed of the shaft, the more problems arise in durability.

Further, when the pressure on the high pressure side 1 fluctuates, the lip portion 7 has a rigidity, so it has poor ability to follow the pressure, and has drawbacks such as leakage of liquid on the high pressure side 1.

Therefore, the present invention was made to solve the above-mentioned drawbacks, and the lip part of the pressure seal is not affected by the pressure on the high pressure side, so that the contact force of the lip part is always constant, and the sealing performance is improved. It is designed to have followability under any circumstances.

In other words, even when the shaft is slightly eccentric under high pressure, the lip portion has good followability and sealing performance is excellent, and even when the shaft rotates at high speed, the lip portion has good followability and sealing performance is excellent. The main objective is to obtain a pressure-resistant seal with excellent properties and durability.

Further, the present invention provides a durable, inexpensive pressure-resistant seal with excellent sealing performance, in which the contact pressure of the lip portion is not affected by pressure even in a high-pressure state, as a seal in the field of high-pressure sealing devices.

A feature of the present invention is that in a pressure-resistant seal having an annular fixed portion and an annular lip made of a rubber-like elastic material, the lip portion extends in the axial direction from the high-pressure side surface of the lip portion, and the lip portion makes sealing contact. A convex portion that forms a gap between the mating circumferential surface and the lip portion is provided integrally with the lip portion, and a contact portion that fits into the fixed portion and a retaining portion that fits into the convex portion are provided. At least one of the joint parts is inserted between the fixed part and the convex part, and the gap between the convex part and the peripheral surface to be in seal contact is The pressure acting from the side and the pressure acting from the pressure receiving member side are set in opposite directions and are set to be approximately equal, thereby eliminating the influence of the fluid pressure on the high pressure side on the lip portion.

Therefore, even if the pressure on the high-pressure side is high or the pressure changes, the contact surface pressure of the lip with the other side is due to the tension force of the lip itself and the annular pressure pressed from the opposite side of the lip contact surface. It is kept constant only by the tension of the spring.

Next, preferred embodiments of the present invention will be explained in detail.

FIG. 2 is a half sectional view of an embodiment of the present invention, in which an annular lip portion 11 is provided on one relatively rotating shaft 3 in order to seal between the high pressure side 1 and the low pressure side 20 of the shaft penetrating portion. are in sealing contact with each other, and an annular fixing portion 12 is fixed to the other shaft hole 4.

That is, this pressure-resistant seal has a lip portion 11 and a fixed portion 1.
2, has a cross-sectional annular reinforcing ring 21 therein, disposes a dust lip 22 in sealing contact with the peripheral surface of the shaft 3 on the low pressure side 2, and is integrally formed of a rubber-like elastic material. It is something.

An annular convex portion 15 is formed on the high pressure side 1 of the lip portion 11 with a gap 14 having an inner diameter larger than the outer diameter of the shaft 3, and the gap 14 side of the convex portion is defined as a convex gap side pressure surface 18. This is what was done.

An annular spring 20 is attached to the outer periphery of the contact surface of the lip portion 11 so as to suppress the contact surface of the lip portion 11.

The pressure receiving member 17 has an annular shape and is inserted between the fixed part 2 and the convex part 15 , the inner side of which is in close contact with the outer periphery of the convex part 15 to form the engaging part 13 and the side surface of the high pressure side 1 . A pressure receiving member pressure surface 19 is formed on the pressure receiving member pressure surface 19, and while the other side is in close contact with the inner circumferential surface of the fixed part 12, it extends to the inner surface of the pressure seal and is fixed in the axial direction.
6.

The engaging part 13 that is in close contact with the convex part 15 of the pressure receiving member 17 is made of synthetic rubber material to have some elasticity in the radial direction, and the other contact part 16 that is in close contact with the fixed part 12 can be fixed. It is made of metal.

This contact portion 16 may be made of plastic material.

The pressure receiving member pressure surface 19 is arranged so that the pressure on the high pressure side 1 acts on the convex gap side pressure surface 18 on the gap 14 side of the convex portion 15 and is generated in the radial direction, and a reaction force is generated by the same pressure. It is formed.

Next, another implementation of FIG. 3 will be described.

The structure of FIG. 3 is substantially the same as that of FIG. 2 except for the pressure receiving member 17.

Therefore, description of the same constituent parts will be omitted.

The pressure receiving member 17 is formed of an engaging portion 13 and a close contact portion 16, and has a pressure receiving member pressure surface 19 and a pressure surface 18 on the side of the gap between the protrusions. An annular groove is provided in the groove, and an annular pressure receiving member pressure surface 19 is provided on the outer periphery of the high pressure side 1 of the groove.

A portion corresponding to the convex gap side pressure surface 18 is provided on the inner periphery.

The other contact portion 16 can be brought into close contact with the inner circumferential surface of the fixed portion 12 and is made of a group rubber material that is formed to have elasticity in the radial direction.

Since the contact portion 16 is in elastic contact, the pressure receiving member 17
In order to fix the pressure-receiving member 17 in the axial direction, an annular auxiliary member 31 made of metal is fixedly disposed between the side surface of the pressure seal and the pressure-receiving member 17.

In the embodiment, the engaging portion 13 and the auxiliary member 31 are made of metal, but it goes without saying that other materials can be used as long as they can withstand the pressure on the high pressure side 1.

The contact part 16 is made of synthetic rubber material, but since the purpose is to allow the pressure receiving member 17 to move slightly in the radial direction in and out by pressure, it may be made of other rubber-like elastic material or fixed material. It is also possible to use a means that is sealed with the inner circumferential surface of the portion 12 and whose movement can be adjusted slightly in the radial direction.

As in the case of the embodiment shown in FIG.
The force acting radially outward is approximately equal to and opposing the force.

The convex gap side pressure surface 18 functions as explained in FIG. 2, and since the pressure receiving member 17 extends toward the gap 14 side, it also serves as the convex gap side pressure surface 18.

The configuration described above provides the following effects.

The pressure-resistant seal of the present invention is installed on the high-pressure side 1 and the low-pressure side 2 of the shaft penetration part.
In order to seal between the shaft 3 and the shaft hole 4, which rotate relatively, when pressure is applied to the high pressure side 1, the convex gap side pressure surface 1
8, a force is applied radially outward from the gap 14 side.

Therefore, the annular convex portion 15 expands outward, and the lip portion 11 connected to the convex portion 15 also tends to expand radially outward.

On the other hand, since the same pressure simultaneously acts on the pressure receiving member pressure surface 19 between the pressure receiving members attached to the circumferential surface of the convex portion 15,
A force substantially equal to and opposite to the force acting on the convex gap side pressure surface 18 acts on the pressure receiving member pressure surface 19 inwardly in the radial direction.

Therefore, since these opposing forces in the radial direction act on each other, the lip portion 11 at the end of the convex portion 15 is not expanded outward in the radial direction as described above, and high pressure is applied to the high pressure side 1. In other words, even if the pressure on the high pressure side 1 is high or the pressure changes, the radial contact surface pressure of the lip part 11 with the shaft 3 is hardly affected. The contact pressure with the shaft 3 can be kept almost constant at all times due to the inherent tension of the lip and the compression of the annular spring 20.

In Fig. 2, the engaging part 13 of the pressure receiving member 17 is made of synthetic rubber and engages with the convex part 15, so even if a slight eccentricity occurs on the shaft 3, the eccentricity is absorbed and the seal is sealed. This is an embodiment designed to do so.

Since the pressure receiving member 17 is in close contact with the inner circumferential surface of the fixed portion 12 and the outer circumferential surface of the convex portion 15, the pressure of the high pressure side 1 does not act on the annular spring 20 side of the lip portion 11.

Also, the pressure on the high pressure side 1 acts in the axial direction, but the pressure receiving member 17
It is fixedly supported by the contact portion 16.

FIG. 3 shows that even when the pressure on the high-pressure side 1 is high or the pressure fluctuates, the lip portion 11 is maintained by including the convex portion 15 in the annular groove provided in the engaging portion 13 of the pressure-receiving member 17. This is an embodiment that is maintained so as not to have any adverse effects.

Further, the force that the pressure receiving member 17 receives in the axial direction due to pressure is supported and fixed by the auxiliary member 31.

As described above, even if eccentricity occurs in the relatively rotating shaft or one of the shaft holes when the pressure on the high-pressure side of the other side to be sealed is high, the lip portion follows the eccentricity and seals by sliding. However, since the contact pressure is constant, the sliding surface of the lip part does not wear out, making it durable and excellent in sealing performance.

In addition, even if the relatively rotating side rotates at high speed, the sliding contact surface with the lip part is not affected by the pressure on the high pressure side, and the contact is always at a constant pressure, so it is durable without wearing out. It has excellent sealing properties.

Furthermore, even if the pressure on the high pressure side fluctuates, the lip part is constructed so that it is not directly affected by the pressure fluctuation, so the lip sliding surface is not affected by it, and the contact is always at a constant pressure, which is optimal. Therefore, it has an excellent effect on durable sealing performance.

Moreover, since the structure is simple, the price can be reduced.

As a result of the above effects, the present invention provides a durable and inexpensive pressure-resistant seal that has excellent sealing properties even under high pressure and high speed rotation.

[Brief explanation of the drawing]

FIG. 1 is a half-sectional view showing a conventional pressure-resistant seal installed, and FIGS. 2 and 3 are half-sectional views showing the installed pressure-resistant seal of the present invention. 1...High pressure side, 2...Low pressure side, 3...
...Shaft, 4...Shaft hole, 11...Lip part, 12...Fixed part, 13...Engaging part, 14... ...Gap, 15...Protrusion 1
6... Close contact part, 17... Pressure receiving member, 1
8...Protrusion gap side pressure surface, 19...Pressure receiving member pressure surface, 31...Auxiliary member.

Claims (1)

[Claims] 1. In a pressure-resistant seal that seals between a high pressure side 1 and a low pressure side 2 of a shaft penetrating portion, a shaft 3 that is made of a rubber-like elastic material and that rotates relative to the shaft 3 is provided. An annular lip portion 11 that is in sealing contact with one circumferential surface of the shaft hole 4 passing through, an annular fixed portion 12 that is fixed to the other circumferential surface of the shaft 3 and the shaft hole 4, and a portion from the lip portion 11 to the high pressure side. It extends integrally towards 2,
A gap 14 is formed between the lip portion 11 and the circumferential surface in sealing contact.
an annular convex portion 15 forming an annular convex portion 15 , a close contact portion 16 that sealingly fits with the fixing portion 12 , and an engaging portion 13 that sealingly fits with the convex portion 15 . It has a pressure receiving member 17 that can be displaced in the direction, and pressure is applied to the convex portion 15 from the convex gap gap side pressure surface 18 side and from the pressure receiving member side pressure surface 19 due to the fluid pressure in the high pressure side 1. A pressure-resistant seal characterized in that the pressure is similar to that of the seal. 2. The engaging portion 13 of the pressure receiving member 17 is formed to be deformable,
A pressure-resistant seal according to claim 1, wherein the contact portion 16 is fitted into the fixed portion 12. 3. The pressure receiving member 17 has an annular groove into which the engaging portion 13 or the convex portion 15 is inserted, and the contact portion 16 is sealed and engaged with the fixed portion 12 so as to be movable in the radial direction. Pressure-resistant seal as described in section.