Design of a 27 kW 100 krpm permanent magnet rotor and bearing system

Abstract

High-speed machines can provide greater power relative to their size and weight, making them perfect for use in space-constrained and weight-sensitive applications like aerospace and electric vehicles. In this work design of a permanent magnet synchronous machine (PMSM) with a solid circular magnet, compressed by a shrink-fitted titanium alloy sleeve is presented. The rotordynamic assessment, Campbell diagrams, and unbalanced response in line with API 617 standards are used to find critical speeds and address the need for damping. Damping is achieved with ball bearings employing squeeze film dampers (SFDs) that are stabilized by O-rings. The stiffness of these O-rings, affected by frequency, is estimated using finite element analysis and prior dynamic studies. Analysis confirms that the rotor’s unbalance response is adequately damped with this setup.