Joining techniques of the rotor segmentation of PM-synchronous machines for Hybrid drives

For Hybrid-, Fuel Cell- and battery cars in the future electric motors in a high volume production are required. In the production of these electric motors the manufacturing of the laminated rotor core was identified as a possible cost potential. For electromagnetic reasons, the rotor of a PM synchronous machine is constructed of packaged electrical steel. First, the individual sheets of the rotor are punched in full cut. Subsequently, the packing of individual sheet occure by baking, welding or interlocking. To optimize the sheet utilization level, the rotor laminations can be punched in segments. Afterwards they have to be rebuilt into a ring form by using different joining techniques. In this paper the specific advantages of the rotor segmentation, whose mathematical basis in terms of bond strength and the different joining techniques are presented. The focus will be placed on the results of the research and development work of the joining technology joint geometry.