Automatic single plane balancing of a rigid rotor using an electromagnetic balancing head

Abstract

The electromagnetic balancing head which is developed to balance a rotating rotor without interrupting the normal operation, has some drawbacks due to the nonlinearity of the system and the presence of the unstable operating region. The characteristics of the balancing head are examined so as to improve the floating mass supporting system of the balancing head and the equations of motion of the floating mass system are solved via analytic and numerical methods to investigate the stable operating region. For the automatic balancing experiment, the trial and error algorithm is applied to a single plane rotor for reducing the norm of the synchronous response of a bearing housing, using a microcomputer based controller. Experimental and analytical results show that the electromagnetic balancing head is suitable for low speed balancing while it is not appropriate for high speed machines because of its inherent instability problem.