A Study on Run-Out Characteristics of Externally Pressurized Gas Journal Bearing : Rotor Run-Out Characteristics

The run-out characteristics of a rotor supported by an externally pressurized gas journal bearing are analyzed theoretically with special attention paid to the relationship with the machining errors of the bearing system. Both the static and dynamic run-out characteristics are discussed. The form deviation of the rotor cross section (i. e., out-of-roundness error) is attributable as the critical factor which may govern the run-out characteristics of the rotor. The effects of size deviation of the supply holes are also investigated. The obtained results may reveal a fundamental concept of the precision design of an externally pressurized gas bearing with respect to the rotating accuracy of the rotor.