Gas lubrication hydrodynamic sealing device used for miniature high-speed turbo expander

Abstract

The invention discloses a gas lubrication hydrodynamic sealing device used for a miniature high-speed turbo expander. The miniature high-speed turbo expander comprises a shell, wherein a main shaft and an impeller component are arranged in the shell; the impeller component is fixed on the main shaft; a bearing component is arranged out of the impeller component; the bearing component is sheathed to the main shaft; the sealing device is positioned between the impeller component and the bearing component and comprises a movable ring and a static component; the movable ring is sheathed to the main shaft; two ends of the movable ring are clamped between the impeller component and the bearing component; the static component is fixed on the shell; one end surface of the static component and themovable ring form a sealing surface; an end surface, which is laminated with the static component, on the movable ring is provided with a fluid hydrodynamic groove. Compared with the prior art, the sealing device disclosed by the invention is applied to the high-speed turbo expander, the zero leakage of bearing side lubricating oil to an exit side of the expander can be realized, and in addition,the internal gas loss of the expander is extremely small.

Description

technical field [0001] The application relates to the technical field of mechanical seals, in particular to a gas-lubricated dynamic-pressure sealing device for a miniature high-speed turbo expander. Background technique [0002] At present, the exhaust emission of diesel engines used in heavy trucks has become a source of pollution to the atmospheric environment that must be considered and paid attention to. With the government's increasing yearly emission standards for automobiles, including heavy-duty trucks, a micro-turbo expander that uses the exhaust of heavy-duty trucks as the working medium and generates power externally has emerged as the times require. Due to the extremely small size of the main shaft of the micro-turbo expander, the shaft diameter is generally less than 10mm, but its rotating speed is extremely high, often reaching above 100,000rpm, and some are even higher. For such a high-speed micro-turboexpander, the seal between the exhaust side and the bear...

AI Technical Summary

Problems solved by technology

Since the working gap between the non-contact labyrinth seal and the main shaft is relatively large, it will cause three problems: first, the flow rate of air purging is relatively large; second, it will cause the loss of bearing lubricating oil; third, Lubricating oil containing additives may enter the working chamber of the micro expander, which will adversely affect the work of the micro expander

It can be seen that the current form of shaft end seal is difficult to meet the working needs of the micro high-speed turbo expander

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