Gas film face seal structure for cantilever-type foils

Abstract

The invention discloses a gas film face seal structure for cantilever-type foils. The gas film face seal structure comprises a dynamic ring and a static ring which are in gas film face seal; the seal face of at least one seal ring of the dynamic ring or the static ring is a cantilever-type foil face; the cantilever-type foil face comprises a circular ring-shaped ring body, a plurality of foils and dowels, wherein each foil is made of an elastic material; the inner side of the ring body is bulged to form a circular ring step; a seal dam is formed on the upper surface of the circular ring step; the foils are laid on the circular ring concave surface of the outer side of the seal dam end to end; the foils are evenly distributed along the circumference in a fan shape; one end of each foil is fixed to the ring body, and the other end of each foil is free; the free end of each of the foils is hung above the fixed end of the previous foil; the upper surface of the free end of each foil is flush with the plane of the seal dam and is higher than the upper surface of the fixed end; the peripheral directions from the fixed ends to the free ends of the foils are respectively consistent with the circumferential direction of airflow; each foil is divided into a plurality of small pieces along the radial direction from the free end to the fixed end, wherein the small pieces at the inner side are wider than the small pieces at the outer side. The gas film face seal structure disclosed by the invention has the characteristics that the stability is high, the abrasion is small, the service life is long, the reliability is high, high temperature can be resisted, the rotation speed is high, and the adaptivity is strong.

Description

(1) Technical field [0001] The invention relates to the technical field of mechanical end face sealing structure design, in particular to a cantilever type foil end face air film sealing structure, which is especially suitable for shaft end sealing devices of various high-speed rotating machines. (2) Background technology [0002] As a new type of mechanical seal, the end face air film seal is widely used in the shaft end seal of rotating machinery, such as compressors, pumps, reactors and fans, due to its significant performance advantages such as low leakage, low power consumption, and long life. And other rotating machinery. With the rapid development of modern rotating machinery, mechanical seals are required to develop to high parameters (such as high speed, high temperature, high pressure, etc.), and have higher stability and reliability and longer service life. Under these conditions, the traditional air film seal on the end face is prone to instability. Under high t...

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Problems solved by technology

[0005] Drawing on the relevant principles of foil thrust bearings, the concept of a dynamic pressure foil end face seal has been proposed abroad, and related reports have appeared, such as the US patent US0207158 "Hydrodynamic foil face seal", although the sealing structure designed in this patent has certain The self-adaptive ability can effectively improve the high-speed operation stability of the seal, but the leakage rate is difficult to control, and it needs further research to further improve the self-adaptive ability of the seal under variable working conditions. At the same time, there are many structural parts and the processing technology is complicated , and the requirements for machining accuracy are high, and the manufacturing cost is expensive, which also greatly limits the popularization and application of foil end seals

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