RU2306466C2 - Method of sealing of rotating shaft and seal used for this purpose - Google Patents

Abstract

FIELD: pipeline valves and fittings.

SUBSTANCE: invention relates to stern-tube seals of rotating ship shaft and it can be used for sealing of shafts of rotating pipeline fittings. According to proposed method of sealing of rotating shaft, sealing member is made in form of ring coils made of elastic material, one edge of which is rigidly and hermetically secured on hull structure and other edge is twisted around shaft axis in direction to reduced diameter of soils by inner surfaces in contact with surface of shaft to be sealed. Seal of rotating shaft contains rectangular section ring coils fitted around rotating shaft. One edge of coils is hermetically and rigidly secured on fixed hull structure. Opposite coil is provided with flexible member pressing it to other coils and twisting it around axis of shaft to decrease diameter of coils.

EFFECT: simplified sealing of rotating shaft, reduced cost and improved reliability of joint.

5 cl, 1 dwg

Description

The invention relates to a stern seal of a rotating ship shaft and can be applied in the chemical industry, mechanical engineering, and other industries. In addition, the proposed technical solution can be applied when sealing rotating shafts in pipe fittings (taps, valves and other products).

There are various types of seals of rotating shafts, which are usually performed face: with a bellows, with a ring and a sleeve, with a membrane and others. These types of seals are given in the book by A. I. Golubev, “Modern Seals of Rotating Shafts,” MASHGIZ, Moscow, 1963, page 7.

The closest technical solution to the claimed one is the design of the mechanical seal, given in the reference manual edited by A. I. Golubev and L. A. Kondakov, “Seals and sealing equipment, Moscow, Engineering, 1986, p. 288. The mechanical seal consists of a friction pair made in the form of two sealing rings adjacent to one another on a flat end. One of the rings is fixed either in the housing or on the shaft and sealed with a sealing element. The other ring has freedom of angular and axial movements and is installed in the elastic element. This technical solution is taken as a prototype of the claimed.

The disadvantages of the mechanical seal are the design complexity, the presence of two sealing elements (movable and stationary), increased wear of the mechanical seal due to its location on a larger diameter compared to the outer diameter of the shaft being sealed.

The aim of the present invention is to reduce the cost of sealing, increasing the reliability of the connection and increasing its service life.

To achieve these goals, it is necessary to solve a number of problems consisting in simplifying the design, reducing the number of parts, reducing linear speeds in the friction pair.

These goals are achieved in a method of sealing a rotating shaft passing through a fixed housing structure consisting in the fact that the elastic element of the friction pair is made in the form of elastic ring turns. In this case, one of the extreme turns is rigidly and hermetically fixed to the flange of the fixed housing structure, and the other extreme turn is rigidly and hermetically fixed to the movable flange, with which the turns are pressed against each other in the axial direction and twisted in the direction of decreasing diameter, until the inner surfaces of the turns are in contact with a sealed shaft surface, which is another element of a friction pair.

Part of the elastic ring turns can be made of a material forming friction pairs in the axial direction.

The seal of the rotating shaft passed through the housing surface has an elastic element of a friction pair enveloping it. This elastic ring element is made in the form of annular turns of rectangular cross section. One extreme turn is hermetically and rigidly fixed on a fixed flange, which is rigidly and hermetically fixed on a hull structure. The opposite end turn is rigidly and hermetically connected to the movable flange. The movable flange is connected with elastic elements, for example, springs, which ensure that the end surfaces of the coils are pressed together and twisted around the shaft axis in the direction of reducing the diameter of the coils until they contact the shaft.

A part of the ring turns with respect to the neighboring ones can be made of material forming friction pairs in the axial direction.

The extreme turns can be performed with a large inner diameter relative to the average.

A device explaining the method of sealing a rotating shaft is shown in the drawing.

The rotating shaft 1 passes through the housing structure 2. The fixed flange 3 is rigidly and hermetically attached to the housing structure 2. The tightness is achieved by the sealing element 6. The extreme elastic ring coil 7 is rigidly and hermetically attached to the flange 3. The opposite extreme elastic ring coil 7 is rigidly and hermetically connected to the movable flange 4. Between the extreme turns 7 are the middle turns 8. The fixed flange 3 and the movable flange 4 are interconnected by springs 5, located at an angle to the shaft axis and dressed in a stretched (working) condition. The drawing shows the extreme coils 7 made of steel with a large inner diameter with respect to the middle annular elastic coils 8. However, these coils can be made of medium coils, for example, fluoroplastic with graphite filler with an inner diameter, as in the middle coils. For installation on non-removable shafts, parts 3, 4 and 6-8 are detachable with subsequent connection during installation. The middle elastic coils 8 can be solid and installed using a specially developed technology (installation technology will be described in the next application). To protect large and expensive shafts from wear during friction, they can be fitted with a lining in contact with the middle turns 8. The number of turns 7 and 8 can be any, and the minimum number of turns is 1.0.

Between the elastic ring coils 8 can be installed additional coils of material forming pairs of friction during the radial movements of the coils 8 with each other during beating of a rotating shaft.

The device operates as follows. Suppose this is a marine stern-sealing device. Then the body structure 2 is a partition, behind which there is water. From the septum side, water can only reach the middle elastic ring turn 8, since it is in contact, in inner diameter, with the sealing surface of the shaft 1 (or facing) and on the end surfaces with the extreme turns 7. In the drawing, the sealing contacts are created by springs 5, which due to the angular arrangement with respect to the shaft axis create forces directed axially (along) and radially (perpendicularly) to the shaft axis. Axial force provides pressing of the end surfaces between the turns. Radial force creates a moment twisting the annular elastic coils around the shaft, which causes a decrease in the inner diameter of the middle annular elastic coil 8 to contact with the shaft.

When the shaft 1 rotates, it has a runout. This runout is transmitted to the middle annular elastic coil 8, which has the freedom of radial movement with respect to the extreme ring elastic turns 7. As the shaft 1 rotates, the surfaces rubbing together in the radial and axial directions are first ground together, and then they wear out. Depreciation is compensated by springs 5 due to the axial and radial movement of the friction surfaces of the turns.

Claims (5)

1. The method of sealing a rotating shaft passing through a fixed housing structure, which consists in axial pressing of the elastic element of the friction pair, characterized in that the elastic element of the friction pair is made in the form of elastic annular coils, one of the extreme coils being rigidly and hermetically fixed to the flange of the fixed enclosure structures, and the other to the movable flange, with which the coils are pressed against each other in the axial direction and twisted in the direction of reducing the diameter of the coils, the inner surfaces of which They contact the sealing surface of the shaft, which is another element of the friction pair. 2. The method according to claim 1, characterized in that between the elastic ring coils are arranged coils of material forming friction pairs in the axial direction. 3. The seal of the rotating shaft, containing the rotating shaft passed through the stationary housing structure and the elastic element of the friction pair enveloping it, characterized in that the elastic element is made in the form of circular turns of rectangular cross section, one extreme turn is hermetically and rigidly fixed to the fixed flange, which, in in turn, it is rigidly and hermetically attached to the hull structure, and the opposite end turn is rigidly and hermetically connected to the movable flange, while the movable flange is connected to elastic elements ntami ensuring pressing of the end surfaces between the turns and twisting them about an axis of the shaft in the direction of reducing the diameter of coils to contact the shaft. 4. The seal according to claim 3, characterized in that between the annular coils are coils of material forming friction pairs in the axial direction. 5. The seal according to claim 4, characterized in that the extreme turns are made with a large inner diameter relative to the average.