Assessing the effects of induction rotor transient heating on shaft interference fit during force-stopped condition

Abstract

This article investigates the design and finite element analysis of minimum interference fit between the shaft and motor rotor against force-stop condition, to avoid slip at the interface during transient heating of the rotor This condition occurs when the shaft is locked from rotation and the rotor is subject to the current induced by locked rotor for a certain period of time. Precise assessment of this time period is crucial for the protection of the induction motors, so that protective circuits can be designed to interrupt the current before this time is reached to avoid a spun shaft. The close to reality representative finite element analysis of such a system can offer many advantages during the design phase by eliminating the need for actual experiments, thus reducing both design cost and time. In this article, such a representative model is built and the required design requirements are demonstrated on the example induction motor rotor for two different interface fit values with friction.