Brush type sealing and fingertip sealing combined seal

Abstract

The invention provides a brush type sealing-fingertip sealing combined seal. According to the brush type sealing-fingertip sealing combined seal, the total axial thickness generally does not exceed 2mm; the outer diameter roots of a brush wire bundle, a high-pressure fingertip sealing sheet and a low-pressure fingertip sealing sheet are fixed and clamped between a front baffle and a back baffle through a fusion welding process, so as to form a fusion welding area; the low-pressure fingertip sealing sheet is in direct contact with the back baffle, so as to commonly support an upstream sealing structure; the internal diameters of the brush wire bundle, the high-pressure fingertip sealing sheet and the low-pressure fingertip sealing sheet are in contact with the rotor or keep a very small gap. Compared with the existing brush type sealing-fingertip sealing structure, the structure of the brush type sealing-fingertip sealing combined seal has an obviously higher bearing capability under the same axial thickness condition; the flexibility is not obviously reduced; the leakage amount has no obvious variation or reduction, so that the brush type sealing-fingertip sealing combined seal is applicable to the fields with higher requirements on the bearing capability of the seal, the lightness and the miniaturization.

Description

technical field [0001] The invention belongs to the technical field of mechanical seals, and in particular relates to a composite seal of a brush seal and a fingertip seal which can improve the pressure bearing capacity of the seal. Background technique [0002] In turbomachinery, especially in aero-engines, it is often necessary to seal different pressure chambers, and the sealing forms between rotating parts and stationary parts usually include toothed seals, brush seals and emerging fingertip seals. The grate tooth seal is a non-contact seal. In order to ensure that the seal grate tooth and the rotating part do not interfere destructively, there is generally a considerable gap between the grate tooth and the rotating part, which leads to a large leakage. The brush seal is a kind of flexible contact seal, its leakage is 1 / 5-1 / 10 of the grate tooth seal, and it allows the transient serious inconcentricity between dynamic and static to keep the sealing ability unchanged, whi...

AI Technical Summary

Problems solved by technology

It is worth pointing out that due to the inherent flexibility of brush seals and fingertip seals, their single-stage pressure bearing capacity is not high, generally not exceeding 1MPa. Plastic deformation of downstream kinks leading to seal failure and irreversible damage to the seal

Therefore, in aero-engines and their engineering attempts, it is often necessary to apply multi-stage brush seals or fingertip seals, or form a multi-stage structure with several ricochet seals, which will greatly increase the weight and space of the seals, which is not suitable for aero-engines. The development trend of light weight and miniaturization

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