The Influence of Flexibly Mounted Ways of Seal Rings on Dynamic Tracking of Dry Gas Seal

The perturbation film pressure governing equations of spiral groove dry gas seal are presented by perturbation method based on gas lubrication theories, and the dynamic force coefficients of gas film are got in the condition of high-speed and high-pressure. The motion equations of flexibly mounted rings of the flexibly mounted stator, the flexibly mounted rotor, the flexibly mounted stator and rotor dry gas seals are solved by using the dynamic stiffness and damping of gas film when the axial vibration is taken into consideration. The dynamic tracking property of the three typical configurations is analyzed under the different excitation amplitude, excitation frequency, flexibly mounted ring’s mass, spring stiffness and auxiliary seal damping. The results show that the higher excitation frequency or the larger flexibly mounted ring’s mass can lead to dramatic change of film thickness disturbance of the flexibly mounted stator dry gas seal which means that the dynamic tracking property is bad. When the excitation frequency is lower or the flexibly mounted ring’s mass is smaller, the dynamic tracking property of the flexibly mounted stator dry gas seal is better than the dry gas seal of which rotor is flexibly mounted. In the three typical configurations, the flexibly mounted stator and rotor dry gas seal have the best dynamic tracking property under various conditions.