Characteristics of Self-excited Vibration of Vertical Rotating Shaft System Considering Nonlinearity due to Whirling

Abstract

In a vertical shaft rotor with sliding bearing, especially in a simple two-bearing supported by simple support at upper end and sliding bearing at lower end, it is investigated the self-excited vibration caused by the RD fluid in the sliding bearing. It was shown analytically and experimentally that in the case of a vertical shaft, the Range of rotation speed at which selfexcited vibration occurs is strongly influenced not only by the static eccentric position of the bearing but also by the whirling amplitude of the shaft (depending on the amount of unbalance).