Vibration stability of soft mounted asynchronous machines with flexible shafts and sleeve bearings considering electromagnetic effects

摘要

In the paper the vibration stability of soft mounted asynchronous machines with flexible shafts and sleeve bearings is theoretically analyzed, also considering the electromagnetic influence. Therefore a mathematical model was developed, which is based on a simplified plane machine model. Based on a 2 pole asynchronous machine different calculations were made. In the calculations the maximum rotor speed for vibration stability was investigated. The influence of the foundation stiffness and of the foundation damping on the limit of stability is shown and also the influence of the electromagnetic field. The aim of this paper is to derive a calculation method - shown at a simplified model - which shows the different coherences and the influences, concerning the limit of stability for a soft mounted asynchronous machine, and which helps to optimize vibration stability by choosing suitable foundation stiffness and damping.