INFLUENCE OF UNEQUAL PEDESTAL STIFFNESS ON THE INSTABILITY REGIONS OF A ROTATING ASYMMETRIC SHAFT - 2. INCLINATIONAL VIBRATIONS WITH EFFECTS OF GYROSCOPIC ACTION.

Abstract

The gyroscopic action of a rotor tends to split up the unstable regions which result mainly from the asymmetry of shaft stiffness DELTA into several parts by the inequality of bearing stiffness epsilon . The analysis of this problem is carried out on the assumption that the coefficient of gyroscopic term i//p is as small as epsilon and DELTA , or i//p is larger than both epsilon and DELTA . The position, width and number of unstable regions are analytically determined. As the value i//p increases, the higher side of the split unstable regions becomes larger, but the lower side becomes smaller. The analytical results obtained with the approximation that i//p is large in comparison with both epsilon and DELTA show a good coincidence with results obtained by an analog computer.