A diffuser self-pumping fluid dynamic and static pressure mechanical seal

Abstract

The invention discloses a diffuser self-pumping fluid dynamic and static pressure mechanical seal, which comprises a coaxially arranged moving ring and a static ring, and the first sealing surface of the moving ring includes a diffuser ring groove and a spiral groove from outside to inside There is a back-curved spiral groove in the spiral groove area; the direction of the fluid outlet of the backward-curved spiral groove is opposite to the direction of rotation of the moving ring; a collector ring groove is provided on the second sealing surface of the static ring , in the ring body of the static ring, there is a drainage channel connecting the sealing cavity, the inlet of the drainage channel is located on the outer peripheral surface of the static ring, and the outlet is located in the collecting ring groove; the gap between the second sealing surface and the diffuser ring groove An annular diffuser chamber with radial openings is formed; the first bottom surface of the diffuser ring groove is set as a slope or curved surface radially from outside to inside, and the slope or curved surface gradually moves from inside to outside along the radial direction. close to the second sealing surface. The application can provide a relatively large opening force of the sealing end face and meet the requirement of non-contact mechanical seals with zero leakage and long-term operation.

Description

technical field [0001] The invention relates to a pressure-diffusing self-pumping fluid dynamic and static pressure mechanical seal. Background technique [0002] Non-contact mechanical seals are widely used in centrifugal pumps, centrifugal compressors, gas turbines, steam turbines and other production equipment in petrochemical, aviation, nuclear power and other industries to ensure the seal between the rotating shaft and the housing. At present, there are mainly two forms of dry gas seal and upstream pumping mechanical seal, and the end face structure is as shown in Chinese patent ZL201020106087.8 and US patent US4290611. This type of fluid wedge dynamic pressure mechanical seal relies on the fluid entering the groove from the inner or outer diameter side, and is blocked by the seal dam at the root of the pressure groove to form a high-pressure flow field, which generates an opening force and separates the dynamic and static ring sealing interfaces, reducing Its friction...

AI Technical Summary

Problems solved by technology

However, the self-pumping hydrodynamic mechanical seal solves the problem of blocking the supply subsystem of the fluid, but its disadvantage of small stiffness affects the safety of operation; and the newly proposed magnetic fluid seal and self-pumping hydrodynamic mechanical seal The combined non-contact double-face seal has too low pressure bearing capacity and is not suitable for use as a shaft seal for low- and medium-speed rotating machinery such as centrifugal pumps.

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