Experimental Research on Influence of Seal Fluid Excitation Force on Rotor Bearing System

Abstract

A test rig has been built to study the influence of seal fluid excitation force on rotor-bearing system. The vibration change of rotor near the critical frequency and the stability change of bearing oil-film under the seal fluid excitation force are studied in this paper. The test result demonstrates that the vibration amplitude of rotor is affected by the seal force obviously during the region near the critical rotor speed, the damping effect induced by fluid excitation force is in dominant position near the rotor critical speed on this rotor bearing system. The influence of seal fluid excitation force on stability of bearing oil film is also be studied. The result shows that the begin speed of half frequency component appearance is earlier than the speed of compressed fluid open test. It means the seal fluid excitation force can induce the bearing oil film whirling in advance, and reduce the stability of this rotor bearing system.