An Approach for the Disassembly of Permanent Magnet Synchronous Rotors to Recover Rare Earth Materials

The extensive electrification of the mobility sector is a crucial part for global decarbonization. To enable a successful transition, the availability of resources must be ensured. In particular, rare earth materials used in permanent magnets of permanent magnet synchronous machines (PMSM) are already considered as a critical resource. Therefore, high performance magnets of existing PMSM rotors must be recovered and remanufactured or recycled. A major challenge to recover the magnets is their fixation inside the rotor lamination stack. Hence, this paper presents an overview of remanufacturing and recycling methods for rare earth magnets. Based on this, a disassembly process for PMSM rotors is developed, technical challenges are pointed out and automation solution are proposed. As results of an experimental study conducted on different magnet configurations, four characteristic phases for the magnet disassembly process were identified and magnets with nickel coating showed significantly higher disassembly forces than magnets with epoxy coating. Moreover, analytical and empirical approaches for modeling the consecutive phases of the disassembly process are proposed.