A Case Study of the Contact Force and Stress in the Backup Bearing of a Generator: Experimental Study and Numerical Simulation of Dropdown

Abstract

This paper presents both experimental and numerical study on the dropdown of a generator rotor in a two-stage radial gas turbine utilizing AMB system. The simulation unifies the FE-model of the flexible rotor and the dynamic model of backup bearings. The system under investigation includes a flexible rotor, an axial and two radial AMBs and two backup bearings, double row angular contact ball bearings. The recorded behavior of the studied rotor in the sudden failure of the electromagnetic field is demonstrated. Furthermore, the fine-tuned rotor-system model is used for studying the contact force and the contact stress in the backup bearing. The comparison between the measured results and the simulated results confirms that the used simulation tool can be applied for the design consideration of rotor-backup bearing system and enables to investigate the effect of various design parameters on the dynamic behavior of rotor in the dropdown.