Performance Research On Gas Seal Face Based On Hydrodynamic Effect

A mechanical seal with laser-textured faces is an innovative non-contacting sealing technology, the technology of surface texture is utilized to manufacture micro-pores with certain size, shape and arrangement on the ordinary mechanical seal face, it can achieve non-contacting face seal and well sealing and lubricating performance. Therefore, it has a great significance to research on the design theory of gas face seal to improve the face seal performance.The geometric and mathematical model of the gas face seal is built base on the hydrodynamic lubrication, the finite difference method is utilized to solve the hydrodynamic lubrication equation, the dimensionless pressure distribution of the gas film between the face seal is obtained, and the parameter of the seal performance such as dimensionless open force F, dimensionless leakage Q and dimensionless film stiffness K are also calculated. Then compare with present paper to check the accuracy of the results in this paper.First, the effect of the micro-pores shape on the face seal performance is studied under different structure parameters and working conditions. The results show that:the elliptical and diamond dimple seal face has better hydrodynamic effect, higher leakage; circle, rectangle and triangle dimple seal face is effective in reduce the leakage of the working mechanical seal but the hydrodynamic effect performs poor;when suitable parameters are chose such as area densities Sp?20% or seal clearance h0 ? 2.5μm, the elliptical and diamond dimple seal face has better film stiffness.Second, the effect of the micro-pores bottom shape on the face seal performance is also investigated under different parameters and conditions. The results show that:circle dimple with rectangle bottom has higher open force, film stiffness and obvious higher leakage; while dimple with trapezoid, parabola and triangle bottom is effective in reduce the leakage, the rectangle bottom dimple has better seal performance over all. Finally, the effect of the direction angle of the dimple in the seal face is also researched, the research shows that: when the direction angle is 0?, the mechanical seal appears high open force and leakage, when the direction angle is 45?, the leakage is lowest and the film stiffness shows higher simultaneously. Four kinds of seal face elliptical dimple model with different direction angle distribution are established, all patterns have advantages mutually and the seal performance is better than circle dimple face, the pattern 3 has the best open force while the pattern 1 has the lowest leakage among the patterns. The results provide reference and supplement for the design theory of gas face seal.