SU1364813A1 - Revolving shaft seal - Google Patents

Abstract

The invention relates to a sealing technique, in particular, to seals of rotating shafts by floating rings. The purpose of the invention is to increase the reliability of operation by temperature and hydrodynamic self-regulation of the sealing gaps. The seal includes a housing, inner and outer floating rings, yf mounted on the shaft with sealing gaps and fixed from circumferential rotation with a key in the chamber filled with barrier fluid under pressure. Floating rings are made of composite of several segments, which on the ends are provided with protrusions made on different diameters. Intermediate inserts of material with a linear expansion coefficient greater than that of the material of the n-rings are installed between the protrusions. During the operation of the seal, the segments and intermediate inserts are heated due to the heat gap in the sealing gaps, while due to the greater thermal expansion of the inserts, the angle of the liquid wedge is self-regulated depending on the temperature state of the seal. 2 Il. (L

Description

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The invention relates to a sealing technique, in particular, to seals of rotating shafts by floating rings.

The purpose of the invention is to increase the reliability of operation by temperature and hydrodynamic self-regulation of sealing gaps.

Figure 1 shows the proposed seal; figure 2 - section aa in figure 1.

The seal includes a housing 1, an inner 2 and an outer 3 floating rings mounted on the shaft 4 with sealing gaps 5 and secured from a circumferential twist with a key 6. Chamber 7 is provided for supplying the barrier fluid. Floating rings are made of several segments 8 which are provided at the ends protrusions 9 and 10, made on different diameters. Intermediate inserts 11 are made between segments 8, made of a material with a linear expansion coefficient greater than that of rings 2 and 3. The seal is equipped with springs 12 with guide pins 13 intended to preload the floating rings 2 and 3 against the end surfaces of the housing 1.

Seal works as follows.

During the operation of the machine, the barrier fluid is supplied to the chamber 7 under a pressure exceeding the pressure of the compressed gas. In this case, the barrier fluid, throttling in the sealing gaps 5, prevents leakage of the compressed gas. When the machine switches to another mode, for example, rotation of the pala 4 with a higher frequency, heat generation due to friction in the gap 5 increases. At the same time, the segments 8 of floating rings 2 and 3 and intermediate inserts 11 are heated, the latter being made of a material with a linear expansion coefficient larger than floating ring 2 and 3 material, expanding faster than rings 2 and 3. This leads to an impact on the protrusions 9 and 10 and a change in the thickness of the working medium wedge, for example, oil, and accordingly, gap 3 between shaft m segments 4 and 8. Since temperature and increasing the clearance increases somewhat 5

oil consumption, which increases the heat removal and prevents the occurrence of coking of oil and ringing up. The more the compaction is loaded, the greater the heat release and the greater the angle of the oil wedge, thereby increasing the self-regulation effect, which is automatically determined by the temperature state of the compaction. By reducing the frequency of rotation of the shaft 4, the original size of the gap 5 between the shaft 4 and the floating rings 2 and 3 is restored.

Thus, the proposed seal design of a rotating shaft has a higher reliability due to self-regulation of the gap between the shaft and the floating rings, which ensures the optimal thermal compaction mode, increases its bearing and centering capacity, as well as extreme pressure properties. In addition, such an implementation of the seal design allows one to reduce the guaranteed gap between the floating rings and the shaft and thereby significantly increase the sealing ability of the seal. Self-regulation of the size of the gap allows to reduce the wear of the floating rings, and thus increase the service life.

Claims (1)

Invention Formula The seal of the rotating shaft, comprising a housing, inner and outer floating rings mounted on the shaft with sealing gaps and fixed from circumferential twisting in the chamber filled with sealing fluid under pressure, characterized in that, in order to increase the reliability of operation by thermal and hydrodynamic self-regulation of the sealing gaps , floating rings are made up of several segments, while the segments along the ends are provided with protrusions made on different diameters, between which Intermediate inserts are installed, made of a material with a linear expansion coefficient greater than that of the floating ring material. TV GT 3 P 2 to 4 U2.1 eleven YU