A combined sealing device for a liquid oxygen pump

Abstract

The invention discloses a combined type sealing device for a liquid oxygen pump. The combined type sealing device comprises three non-contact seals sequentially arranged in a series-connected mode, namely the first-stage centrifugal seal, the second-stage dry gas seal and the third-stage floating ring seal. Blades of the first-stage centrifugal seal and dynamic pressure grooves of the second-stage dry gas seal are arranged in the same direction and turn the backs to the inlet of the liquid oxygen pump. A sealing cavity is formed among the second-stage dry gas seal, the third-stage floating ring seal and a sealed case, the sealed case is provided with a fluid channel, and the third-stage floating ring seal is provided with another fluid channel. The combined type sealing device well solves the problems that currently the seal faces of the liquid oxygen pump have wear-out failures or the leakage rate is large, and has the advantages of being long in service life and high in reliability.

Description

technical field [0001] The invention relates to the technical field of fluid sealing devices, and is suitable for sealing the inlet of a liquid oxygen pump, especially the inlet sealing of a liquid oxygen pump for a liquid rocket engine. Background technique [0002] As an important part of the liquid rocket engine, the liquid oxygen pump is used to deliver the low-temperature liquid oxygen required for the engine to work. Since the liquid oxygen pump usually works at a very high speed, and the liquid oxygen is easy to vaporize, it is necessary to supply the liquid oxygen The seal design of the pump brings extremely high challenges. At present, there are mainly two types of seals: one is to set a disengagement mechanical seal at the inlet of the liquid oxygen pump. The opening gap is on the order of millimeters, so it will cause a large amount of medium leakage and reduce the working efficiency of the liquid oxygen pump; the other is to install a contact mechanism at the inl...

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Problems solved by technology

[0002] As an important part of the liquid rocket engine, the liquid oxygen pump is used to deliver the low-temperature liquid oxygen required for the engine to work. Since the liquid oxygen pump usually works at a very high speed, and the liquid oxygen is easy to vaporize, it is necessary to supply the liquid oxygen The seal design of the pump brings extremely high challenges. At present, there are mainly two types of seals: one is to set a disengagement mechanical seal at the inlet of the liquid oxygen pump. The opening gap is on the order of millimeters, so it will cause a large amount of medium leakage and reduce the working efficiency of the liquid oxygen pump; the other is to install a contact mechanism at the inlet of the liquid oxygen pump. The high-speed friction of the end face will cause serious wear of the friction pair, and the leakage of the seal will increase sharply, which will affect the working life and reusability of the engine

[0003] Based on the above, it can be seen that the existing sealing technology of liquid oxygen pumps has the disadvantages of large leakage or severe wear of friction pairs.

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