One of the systems we maintain and optimise at the BMW Group is the HEAT rotor, an electrically heated synchronous motor (ESM). Since it is an electrically heated rotor – wound with insulating varnish – we cast it with a resin-hardener mixture using a vacuum casting process. In this way we achieve, among other things, a higher speed resistance and heat dissipation.

The individual production steps require a wide variety of process steps. For example, the laminated core must be heated and the shaft cooled in a nitrogen bath. Only then can these two components be joined in the Kistler servo press, as high strength is required here. Finally, the power is transmitted to the wheels of a BMW via this shaft.

Our job in maintenance is to rectify complex faults and then analyse them. This then allows us to initiate appropriate measures in order to, in the best case, completely rectify the problem directly. If a complete remedy is not possible right away, we try to take preventive action. Such systems require expert maintenance and inspections to ensure the highest possible availability. All maintenance staff – whether electricians or mechanics – are responsible for specific systems and specialise in the technology in this area. This creates great cooperation and a professional exchange among experts.