The research activity on composite rotor sleeves, recently completed by an international consortium of 15 companies and coordinated by AZL Aachen GmbH, represents a significant step forward for the development of next-generation electric motors.
The project involved a systematic analysis of the state of the art, comparing materials, design strategies, and manufacturing methods for thermoplastic and thermoset carbon fiber composite sleeves, with the goal of optimizing solutions for automotive, aerospace, and industrial applications where high rotational speeds and mechanical containment are critical factors.
Composite rotor sleeves: objectives and methods
The study focused on detailed benchmarks between press-fit and direct-wound designs, comparing thermoplastic and thermoset materials from both mechanical and thermal perspectives. Key indicators such as performance, quality, and industrial scalability were evaluated, and the results have been documented in a detailed 384-page report now available for industrial development.
The next phase will involve experimental validation of the most promising material-process combinations through four work packages. These include the definition of production concepts and materials for testing, development of auxiliary tools for press-fit operations, analysis of winding and fitting on separate rotors with production of sleeves through wet winding, towpreg winding, and thermoplastic tape winding, followed by resistance tests and laminate quality verification. Equivalent tests are planned for direct winding on the rotor, including high-temperature and long-term durability assessments. The final analysis will examine costs, quality, and performance to provide recommendations for industrialization.
Technological implications for electric motors
The technologies developed allow for higher levels of lightness and strength, enabling more efficient motor designs for electric mobility. The collaboration among material suppliers, sleeve manufacturers, and motor builders aims to facilitate the next generation of high-performance powertrains. This collaborative approach between applied research and industrial partners highlights the centrality of composite solutions in the future design standards for advanced electric motors
