RU1775021C - High-pressure sealing device for swivel joints - Google Patents

Abstract

SUMMARY OF THE INVENTION: The axial channel of the rod passes into a radial hole in the middle of the tubular body. A sleeve interacting with the housings is mounted on the shaft with the possibility of relative rotation. The outer surface of the sleeve is stepped with the formation of two symmetrical sleeve protrusions at the ends. Between the protrusions in the sleeve there is a radial hole. A rubber ring and a cup-shaped sleeve made of a deformable material impregnated with lubricant in contact with the bottom jumper with the shaft and pressed against the o-ring are mounted on each protrusion. All radial holes are interconnected. 1 ill.

Description

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The invention relates to a sealing technique for high pressures and can be used in the construction of rotary devices of high pressure process plants (400 M Pa) for cutting materials with a water jet. These devices allow the transfer of fluid under pressure to the moving nozzle, i.e. provide coordinate displacement of the nozzle during the cutting process with minimal friction losses.

A known construction of the device (see AS USSR No. 1513272, class F16 J 15 / 28.1986), which provides the supply of liquid working medium to the rotating parts. It consists of a tubular body with a radial hole in the middle part, of which is located in with the possibility of rotation of the rod with an axial channel and a radial hole in the middle part, and a sleeve interacting with the rod

through an intermediate element and made with a radial hole.

This sealing device has good performance when used at low pressures. However, pressure seals are greater than 1.0. MPa it does not provide.

Also known is the design of a high-pressure sealing device for a rotary (rotary) connection (see Swedish Patent No. 158814. 47 f 23. 1953), consisting of a tubular body with a push sleeve, a sleeve sleeve and a sealed rotary shaft operating by using the phenomenon of a significant pressure drop in a small (a few microns) gap. In this case, the achievement of the required clearance is ensured by the pressure of the medium being sealed on the sleeve sleeve, which on the VJ VJ

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The sealed area is crimped around the sealed rod.

However, the operability of this system at high pressures is ensured by using seals with significant viscosity. When water is used as a working medium, a tight seal is not provided.

The aim of the invention is to drastically reduce the leakage of low-viscosity liquids, mainly water, in high-pressure sealing devices for rotary joints,

This goal is achieved by the fact that in the known design of the device comprising a tubular body with a radial hole in the middle part, a rod with an axial channel passing into a radial hole in the middle part, a sleeve interacting with the body and mounted on the rod with relative rotation and a pressure sleeve, the outer surface of the sleeve is stepped with the formation of two symmetrical sleeve protrusions at the ends, and a radial hole is made in the middle of the sleeve. A rubber sealing ring and a cup-shaped sleeve made of a deformable material impregnated with high-adhesion grease, in contact with the bottom jumper with the rod and pressed against the sealing ring are installed on each sleeve protrusion. In this case, all radial holes communicate with each other.

The need to introduce these differences is due to the following.

A sleeve sleeve with two symmetrical sleeve protrusions is used to create a pressure gradient along the length of these protrusions, thereby achieving a reduction in the pressure level at the ends of the sleeve and a low level of friction forces between the rod and the sleeve sleeve.

A glass-shaped sleeve made of a deformable lubricated medium interacting with the bottom jumper and the sealing rod is used to practically eliminate leaks of low-viscosity liquids (water).

In this case, the cup-shaped sleeve interacts with the end face from the open part with the rubber sealing ring and, under the action of the working pressure of the water, the ring compresses the deformable medium and, as a result, presses it against the surface of the sealing rod under a pressure slightly lower than the working one (due to deformation losses and friction). In this case, a constant takes place from the cup-shaped sleeve

extrusion of a highly adhesive lubricating medium that reduces friction forces.

The cup-shaped sleeve prevents leakage of fluid through the bore in the housing. In addition, under the pressure of the deformable medium, the sleeve protrusions compress the sealing rod, reducing the sealing gap and thereby increasing the pressure gradient.

0 As a result, at high pressures, a sharp reduction in water leakage and negligible friction losses in swivel joints are provided.

The essence of the proposed design

5 of the device is illustrated in the drawing of FIG. 1.

In the tubular body 1 with a radial hole 2 there is a sleeve sleeve 3 with symmetrical thin-walled protrusions 4, interacting with the possibility of relative rotation with the rod 5 with the axial channel and with the radial hole 6.

A radial hole 7 and annular grooves 8 are provided in the sleeve sleeve in the middle part 5.

A rubber sealing ring 9 and a cup-shaped sleeve 10 made of a deformable medium containing lubricant interacting with a bottom jumper with a sealing rod in section 11 are located on thin-walled protrusions.

The power circuit of the device is carried out by nuts 12 through the pressure sleeve 5 13 and the gasket 14.

The housing 1 and the rod 5 are made of stainless steel (for example, EP 817), the sleeve sleeve 3 is made of beryllium bronze, the gaskets 13 are made of brass or

0 beryllium bronze, glass-like bushings 10 —from a deformable medium impregnated with grease (for example, from asbestos or asbestografite winding soaked with preservation grease).

5 The device operates as follows. Small liquid (water) under high pressure (200 - 400 MPa) through hole 2 in housing 1 and through hole 7 and ring grooves 8 in the sleeve sleeve

0 3 and through the radial hole 6 in the rod. 5 enters the axial channel of this rod, through which it is directed to the nozzle or to the next rotary device. Moreover, under pressure, almost constantly

5, the rod 5 rotates relative to the housing (and sleeve sleeve 3) in one or the other direction.

On the length of the symmetrical thin-walled protrusions 4 of the sleeve 3 there is a certain pressure drop in the small gap, however

the resulting pressure gradient does not provide the required compaction.

A sharp reduction in leakage of small liquid is provided by a cup-shaped sleeve 10. Under the action of liquid pressure on the rubber sealing ring 9, it acts on this sleeve from a deformable medium, compressing it and pressing it on a portion 11 to the surface of the sealing rod 5. Moreover, due to pressure losses strain and friction in the contact zone 11 creates a pressure lower than the working pressure in the device. This pressure is necessary as an addition to the pressure gradient created along the length of the thin-walled protrusion 4 of the sleeve sleeve 3. In this case, the high-adhesion lubricant is constantly extruded from the glass-like sleeve. As a result, the practical elimination of leaks (micro-leaks are maintained) of low-viscosity fluids and the minimum possible friction losses during rotation are ensured.

The metal gasket 14 prevents extrusion of the deformable medium into the gap of the sealing joint.

Compared with the prototype, the proposed device design provides

a significant increase in performance due to a sharp reduction in leakage of low-viscosity liquids (water) and due to minimal friction losses during

Claims (1)

turning at high pressures. SUMMARY OF THE INVENTION High-pressure sealing device for rotary joints, comprising a radial tubular body a hole in the middle part, a rod with an axial channel passing into a radial hole in the middle part, a sleeve interacting with the housings mounted on the rod with the possibility of relative rotation, and a pressure sleeve, characterized in that the outer surface of the sleeve is stepped with the formation of two symmetrical sleeve protrusions at the ends, and between them in the sleeve a radial hole is made, and on each sleeve protrusion a rubber sealing ring is installed and a sleeve is stacked in the form of a deformable material impregnated with grease, contacting the bottom jumper with the rod and pressed against the o-ring, with all radial holes communicating with each other. 14