Multi-stage brush type seal of multi-stage differential structure

Abstract

The invention discloses a multi-stage brush type seal of a multi-stage differential structure. The brush type seal comprises a brush type seal installing base, multiple stages of brush type seal unitsand a partition plate. Each stage of brush type seal unit comprises bristle bundles, a front baffle and a rear baffle. In the direction from the upstream stage of brush type seal unit to the downstream stage of brush type seal unit, the radial gaps between the free ends of each stage of bristle bundles and the surface of a rotor are increased stage by stage, and the free ends of the first stage of bristle bundles are in interference fit with the surface of the rotor, the diameters of all stages of bristles and the circumferential tilt angles of the bristle bundles are increased stage by stage, the density and thicknesses of all stages of bristle bundles are reduced stage by stage, the axial distances between all stages of rear baffles and the corresponding stages of bristle bundles are increased stage by stage, the density of all stages of rear baffles is increased stage by stage, and the radial gaps between all stages of front baffles and the surface of the rotor are increased stageby stage. By means of the multi-stage brush type seal, the problem of all stages of unbalanced voltage drop in a traditional multi-stage brush type seal can be solved, it is avoided that a certain stage of bristles fail in advance under the too high voltage drop, and the service life of the multi-stage brush type seal is ensured.

Description

technical field [0001] The invention relates to the field of turbomachinery rotary dynamic seals, and in particular provides a multi-stage brush seal with differentiated structures at various stages. Background technique [0002] The brush seal is a contact dynamic seal with excellent performance, which has strong adaptability to the instantaneous eccentric whirl of the rotor. At present, brush seals have been widely used in aeroengines, gas turbines and steam turbines as a substitute for labyrinth seals. The pressure bearing capacity of single-stage brush seal is limited. Therefore, multi-stage brush seal is usually used under the condition of large pressure difference. However, the geometric parameters of the existing multi-stage brush seal structure are the same at all levels. During the working process of the structure, due to the step-by-step increase of the air flow volume flow through the brush seals of each level, the pressure drop of the downstream stage will alway...

AI Technical Summary

Problems solved by technology

[0004] In view of this, the object of the present invention is to provide a multi-stage brush seal with differentiated structure at each stage, so as to solve the problem that the existing multi-stage brush seal is prone to excessive pressure drop in the downstream stage due to the same geometric parameters at each stage, which leads to seal failure. premature failure problem

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