Hydrodynamic journal bearings can exhibit a particular form of Shaft Differential Heating (SDH) sometimes known as the Morton Effect. This paper presents test data of the Morton Effect in the form of synchronous spiral vibration observed in a 4200 rpm rotating electric machine. With its original partial arc bearings, divergent spiral vibration prevented stable operation above 4000 rpm. Subsequent analytical SDH studies of different bearing types are described which led to a switch to 4 lobe sleeve bearings. The 4 lobe bearing retrofit eliminated the unstable spiral vibration behavior. To the authors’ knowledge, this is the first published instance of a verified case of the Morton Effect to be solved exclusively by a change in bearing hardware with no accompanying changes to the rotor, shaft or journal.

This content is only available via PDF.
You do not currently have access to this content.