SU297257A1 - Collar for shaft sealing - Google Patents

Description

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Known rubber cuffs (seals) for sealing shafts,

The elastic and elastic properties of rubbers are used in these stuffings; however, their properties are adversely affected by such properties of rubbers as poor antifriction (high coefficient of friction) even under the conditions of use of lubricants and poor thermal conductivity. When rubber glands work in the place of their friction with the shaft, a large amount of heat is generated, as a result, due to poor heat transfer of rubber, high temperature develops in the friction meteor, leading to embrittlement and cracks on the working edge of the glands.

A significant number of types of plastics with good anti-friction properties and other anti-friction materials are known, for example, caprone V. polyamides, fluoroplastics, plastics, special plastics with anti-friction fillers (graphite, bronze powder, two-sulfur molybdenum, and also babbit, bronze, cast iron, graphite and other anti-friction materials).

Attempts to replace rubber in stuffing boxes with plastics, i.e. to make the seals of plastics, as well as of other inelastic materials do not have positive results due to the lack of such other and elastic properties of these materials as rubber possess.

The proposed design of rubber reinforced glands with an anti-friction material that has a lining surface allows the use of the positive properties of both materials, which are necessary when working sealing cuffs (glands). The inner working surface of the proposed cuff in order to increase the service life is formed by a set of elastic split rings made of antifriction material fixed in the housing.

Figure 1 is a general view of the reinforced rubber gland, section; Fig. 2 shows the working sealing ring. Fig. 3 shows a spring ring.

The coated cuff for sealing the shafts consists of a rubber casing 1, a metal frame 2, working sealing rings 3 and a spring ring 4.

The rubber body 1 is the main body of the cuff, which connects all the gland parts, carries and takes all the loads during operation and whose elastic and elastic properties ensure reliable sealing work during operation and storage of the machine. The brand of rubber for the manufacture of body 1 must be selected depending on the degree of mechanical load, on the medium (air, water, oil, kerosene, emulsion, etc.) and on the temperature conditions of operation.

The metal frame .2 imparts the necessary rigidity to the structure and ensures a reliable fit of the gland in the slot of the machine unit where it works, as well as a tight, airtight connection of the gland to this socket.

The operating rings 3 are in direct contact with the rotating shaft and must ensure the tightness of the shaft at the place of friction, the rings are made of anti-friction mass, cast iron, copper graphite and other anti-friction materials and pressed into rubber when making the stuffing box. So that the rings fit snugly to the shaft

0 at different temperatures, they have a cut 5. For better fastening of the rings to each other and to the rubber, they are provided with holes b. Gland may have 2-3 or more rings. During the production of the glands, the rings were fixed in the mold in such a way that their cuts 5 would be offset from each other, and the holes 6 would coincide and when pressed, they would be filled with a rubber holding the rings 3 in the housing. Finally, the diameter of the working part of the gland can be either immediately obtained in the mold or mechanically processed after vulcanization of rubber.

The spring ring 4 helps the rubber to create the necessary pressure on the rings, providing a backlash-free fit of the rings 3 to the shaft. The spring ring can be made of spring steel or other spring material. With a sufficiently elastic rubber, spring rings are not required,

Cuff size is determined by

5 by the number of rings 3 and the constructive solution of the unit of their attachment, as well as the conditions under which the gland will work. In the case of the gland in the conditions of shaft shaking

0 and product vibrations, size A, are chosen larger than size l. When the gland works without vibration, size A is less than size A, Size d-, differs from d or very

5 small value (up to 1 mm) or merged with it. The sizes, d, в and Л have the same values as the corresponding sizes of the cuffs, made according to GOST 8752-61:

0

The proposed stuffing box has been tested in the operation of the machine in the presence of abrasive dust. Good results are obtained. Rubber seals on the machine had to be changed several times a month.

And the seals of the proposed design with rings made of antifriction dry plastic under the same operating conditions are simply more than four months, i.e. more than 10 times longer.

Rubber reinforced glands (cuffs 1 with a rubbing surface of antifriction material can be used in aviation, rocket production, automobile manufacturing and mechanical engineering.

Claims (1)

SHAFT SEAL CUFF, made in the form of an armored housing made of an elastic material, such as rubber, with a hole under the shaft, characterized in that, in order to increase the service life, the inner working surface of the cuff is formed by a set of elastic rubber rings of antifriction material fixed in the housing.