Evaluation of Expandable Slot Liners for Reversible, Adhesive-Free Magnet Fixation in Electric Motors

Hahn R, Stauber S, Zürrlein T, Preitschaft A, Ihne T, Franke J, Risch F (2026)

Publication Type: Conference contribution

Publication year: 2026

Original Authors: Roman Hahn, Simon Stauber, Tobias Zürrlein, Anja Preitschaft, Thorsten Ihne, Jörg Franke, Florian Risch

Event location: Funchal (Madeira) PT

DOI: 10.1109/ICEM68283.2026.11757843

Abstract

Permanent magnet synchronous motors require reliable magnet fixation to withstand centrifugal loads, thermal cycling, and vibration. Conventional fixation methods such as epoxy bonding or resin encapsulation complicate end-of-life recycling and magnet reuse due to poor reversibility and residual contamination on the magnet surface. This work investigates expandable slot liners, originally developed for stator winding fixation, as an adhesive-free fixation concept for interior permanent magnet rotors. The proposed approach enables mechanical retention without resins or molding compounds and allows the slot liners to be degraded during thermal demagnetization, enabling clean magnet extraction and reuse. Experimental investigations were conducted on a recycled traction motor rotor stack. Two pre-commercially developed expandable slot liner materials were used, as well as inductive heating for thermal processing. Mechanical press-out tests before and after thermal degradation were compared with epoxy-bonded reference samples. The results demonstrate operational stability while significantly improving magnet extractability and reducing surface contamination after demagnetization.

Authors with CRIS profile

Roman Hahn Lehrstuhl für Fertigungsautomatisierung und Produktionssystematik (FAPS) Simon Stauber Lehrstuhl für Fertigungsautomatisierung und Produktionssystematik (FAPS) Tobias Zürrlein Lehrstuhl für Fertigungsautomatisierung und Produktionssystematik (FAPS) Anja Preitschaft Lehrstuhl für Fertigungsautomatisierung und Produktionssystematik (FAPS) Thorsten Ihne Lehrstuhl für Fertigungsautomatisierung und Produktionssystematik (FAPS) Jörg Franke Lehrstuhl für Fertigungsautomatisierung und Produktionssystematik (FAPS) Florian Risch Lehrstuhl für Fertigungsautomatisierung und Produktionssystematik (FAPS)

How to cite

APA:

Hahn, R., Stauber, S., Zürrlein, T., Preitschaft, A., Ihne, T., Franke, J., & Risch, F. (2026). Evaluation of Expandable Slot Liners for Reversible, Adhesive-Free Magnet Fixation in Electric Motors. Funchal (Madeira), PT.

MLA:

Hahn, Roman, et al. "Evaluation of Expandable Slot Liners for Reversible, Adhesive-Free Magnet Fixation in Electric Motors." Funchal (Madeira) 2026.

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