Investigation on the mechanical and electromagnetical performance of a squirrel cage induction machine with radially laser welded end ring connections

In this paper two different methods for joining the bars and the end rings of copper squirrel cage induction machines by means of laser welding are investigated. Next to an axially welded rotor cage a new rotor design which allows for radially laser welding is presented comprising end rings which are made up of several thin copper discs. The radial welding process permits very short processing times which are important for series production. Furthermore, due to the focused heat impact on the material, the copper disc design allows high circumferential speeds above 150 m/s with pure copper material which may even be increased by using different material combinations. It is shown by means of measurements that the mechanical as well as the performance requirements both are achieved by the induction machine with radially laser welded end ring connections.