UNBALANCE RESPONSE AND STABILITY ANALYSIS OF HORIZONTAL ROTOR SYSTEMSMOUNTED ON NONLINEAR ROLLING ELEMENT BEARINGS WITH VISCOELASTIC SUPPORTS

Unbalance response and stability analysis of a rotor shaft system, wit h the rotor mounted in the middle of a massless shaft, having linear e lasticity and internal damping, with bearings having nonlinear restori ng force characteristics at the ends mounted on viscoelastic support, has been carried out, taking the effect of gravity into account. The r estoring force characteristics of the bearing has been linearized, by the method of effective linearization, thereby enabling an approximate stability analysis using simple techniques. It is found that, unlike the case with a bearing having linearly varying restoring force charac teristics, gravity not only affects the unbalance response but also ca uses a decrease in the stability limits when the restoring force chara cteristics are nonlinear.