Robotiserad demontering av statorer från elbilar för ökad materialåtervinning

Sammanfattning

The demand of electric vehicles is currently increasing rapidly in order to replace fossil fuelpowered vehicles. Simultaneously, concerns are growing regarding the end-of-life components of the electric vehicles, including the electric motor. For a vehicle to be as climate neutral as possible, sustainability must be considered throughout all stages of its life cycle, including recycling. Mission 0 House is a project initiated by EV manufacturer Polestar, with the goal of ensuring that Polestar vehicles are entirely emission free thoughout their life cycle. The purpose of this study is to investigate how material recycling of a stator from an electric motor in a Polestar vehicle can be improved through robotic disassembly. In addition, this study will examine how the recycling of electric motors is currently performed. The project was carried out through physical experiments and interviews with various companies in the industry. The experiments showed that the forces required to extract the copper windings from the stator laminations varied between 900 N and 15,000 N. This made it challenging to develop a concept that was sufficiently flexible to handle the variations. The interviews indicated that there is currently no established method for how recycling of electric motors should be carried out. The concepts developed in this study were evaluated using a Pugh matrix, in order to select the most suitable concept. The winning concept is based on the use of an industrial robotic cell, where operations such as sawing the stator in half, separation of the housing, and extraction of the windings are performed. A specialised tool was designed for the extraction process, adapted to hook into the windings. The conclusion of this study is that robotic disassembly has technical potential, but that implementation is currently limited by both technical and economic factors. This means that further research, studies, and increased interest in recycling are required for robotic disassembly to be implemented. For concepts similar to those presented in this report to become relevant on a larger scale, stronger incentives within the industry are also needed. Examples of this may include new EU directives or stricter legislation regarding material recycling and disassembly of electric vehicle components. Alternative recycling methods should be further investigated and tested for comparison, as well as the possibility of reusing the electric motor as a whole.