ROTOR DYNAMICS OF NON-SYMMETRICAL ROTOR-BEARING-FRAME SYSTEMS.

A linear rotor-beaing-frame system, with anisotropic bearings and umsymmetrical rigid frame, is studied. It is shown that the response due to unbalance can be described with elliptical orbits of rotor and frame points. The elliptical orbit can be split up into two circular orbits: one forward and one backward rotational component. It is proposed that the phase angle should be defined for each component separately. Owing to gryoscopic effects the eigenfrequencies (whirl speeds) are dependent on the spin speed. A simple and very rapid iterative procedure for calculating the eigenfrequencies and corresponding eigenmodes at a specified speed for revolution has been developed.