Rolling and whip phenomenon of hollow rotor slipping on internal stator

Abstract

Dynamic features of a rotor that rolls without or with whipping and slipping of own inner surface on a rigid stator are discussed. Change in the whirling direction associated with the rolling of the rotor from backward to forward was confirmed experimentally, i.e. in the case of an internal type for the stator-limiter in the direction of rotor rotation. Identification of dynamic behavior is made on the basis of eigenfrequencies and eigenmodes, motion orbits of an eccentric point (on the rotor), Campbell diagrams and AFC. The calculation of such characteristics has done using an original mathematical approach developed by the author earlier in order to describe the backward motion of common rotor on an external stator. A good agreement is obtained between the theoretical frequencies and amplitudes of vibration and the experimental ones. Therefore, the author’s technique is also suitable for the revealed forward rotor motion around the internal stator.