Abstract: Taking the rotor-bearing-dry gas seal system as the research object, considering the effect of bearing oil film force and outside instantaneous excitation force on the stability of dry gas seal system, the rotor-bearing-axial vibration model of dry gas seal system is established, a nonlinear Reynolds equation under the microscale is solved by using approximate analytical method, at the same time, the equation of axial stiffness and axial damping of gas film are derived by using the coupled vibration equation, and the calculation is programmed. By analyzing the response time history diagram and phase track diagram under different spiral slot number, the optimal range of spiral slot number for the axial vibration characteristics of the system is investigated. Compare and analyze the stability range of dry gas seal groove parameters of dry gas seal ring-gas film systems and rotor-bearing-dry gas seal system under the actual working conditions, so as to provide theoretical guidance for the research and design of nonlinear stability of dry gas seal.

Key words: dry gas seal, axial vibration, number of grooves