Experiments on Oil-Film Dampers for Turbomachinery

Abstract

Oil-film dampers are used in turbomachinery to suppress undesirable shaft dynamic responses. They are located at the nonrotating outer race of selected main bearings. A rig is described that was designed to evaluate the effect of damper geometry on the rotor responses. Typical test results are shown which indicate that cavitation limits the maximum speed at which dampers should be used. Below cavitation speed the effect of the damper appears predictable with existing theory. More tests are required to substantiate this. At high speeds the damper generates nonsynchronous motion. The damper may have a significant effect on the stiffness of the support felt by the rotor.