Study on the water-lubricated high-speed non-contact mechanical face seal supported by a disc spring

Abstract

A type of non-contact mechanical face seal supported by a disc spring with high bending stiffness is proposed for actual working conditions and may be used in high-speed turbopumps with large axial loads and heavy random vibration. First, the separated speed of the seal is obtained, which shows that the initial contact mechanical seal can transform into a non-contact seal when the rotational speed is higher than the separated speed. Second, the steady-state model is proposed to describe the performance of the seal. The model includes the Reynolds equation, energy equation, lubricant temperature–viscosity relationship equation, and moment equilibrium equation, and the finite-difference method is used to solve the model. Third, with water as the sealed fluid, the effects of the geometric parameters and working parameters (e.g. spring stiffness, axial load, rotational speed) on the main performance parameters (film thickness, the maximum pressure, temperature, power loss, leakage) are obtained. The results show that with an increase in the stiffness of the spring, the film thickness and temperature increase change only slightly. With an increase in seal load, the film thickness decreases and the temperature increases. The film thickness increases and the temperature decreases with an increase in rotational speed. The results show that the proposed mechanical seal supported by such disc spring can be used in turbopump systems with higher speeds and smaller leakage requirements.