Effects of Shaft Geometric Unconformities on the Rotor-Dynamic Behavior in Hard Coupled Equipment

Abstract

Case Study 17: This case study deals with a 25MW turbo-generator train with a semi-rigid connection between generator and gearbox. For this application, machine alignment and connection is a key factor for a smooth rotor-dynamic system behavior: both high run-out and high radial vibration can be induced by poor quality of the assembly. The rotor-dynamics of the train in subject was negatively influenced by a geometrical out-of-tolerance on the generator flange, causing a distortion in the shaft line which introduces a pre-stress on the rotor system. The aim of this case study is to draw the attention on the importance of system integration especially in presence of semi-rigid assembly, which requires specific design, manufacturing and integration requirements.