Work packages within the Joint Partner Project (JPP). Source | AZL Aachen GmbH

Following the successful completion of its comprehensive market and technology study on composite rotor sleeves, AZL Aachen GmbH (Germany) is taking the next step with a new cross-industry collaboration, “Composite Rotor Sleeves – Experimental Testing & Benchmarking.” Building on insights generated with a consortium of 15 partner companies, this Joint Partner Project (JPP) moves from theoretical comparison to applied experimental validation. Its aim is to benchmark composite rotor sleeve materials and manufacturing technologies under application-oriented test conditions — offering participants decision-ready data on performance and cost efficiency. 

Within this project, AZL’s engineering team will systematically investigate how different sleeve materials and manufacturing routes perform under realistic mechanical and thermal loads. The project will include wet filament winding, towpreg winding and laser-assisted thermoplastic tape winding technologies, focusing on both press-fit and direct-wound rotor sleeve concepts. Comparative benchmarking will evaluate structural integrity, pre-stress behavior and temperature-dependent performance, while also quantifying production efficiency and cost-related key performance indicators (KPIs).

The initiative leverages AZL’s infrastructure, combining design, manufacturing and testing capabilities in one location on the RWTH Aachen Campus. Using specially developed testing setups — including a radial-load test rig and pre-stress analysis fixtures — the AZL team will replicate real-world operating conditions without the need for rotation. Static, cyclic and creep tests at elevated temperatures will deliver deep insights into material and structural performance. Alongside the technical evaluation, the project includes a technological and economic assessment to identify the most efficient material and process combinations for industrial application.

The project’s collaborative setup enables companies from the entire composite and e-mobility value chain to jointly address key design and manufacturing challenges. “As a high-volume manufacturer in the field of rotor sleeves, Schunk considers it essential to actively shape innovation,” notes Fabian Köster, development engineer composites at Schunk Kohlenstofftechnik GmbH, a project participant. “Participation in the accomplished AZL project underlines our belief that future viability and competitiveness can only be secured through early involvement in technological developments. The AZL information event offers OEMs and partners across the entire value chain an opportunity to exchange insights on the current state of rotor sleeve technologies, explore emerging trends and jointly develop solutions for tomorrow’s challenges.”

According to Philipp Fröhlig, head of industrial services at AZL Aachen GmbH, there is additional, broader value behind the JPP approach: “We translate peak trend topics discussed within the various forums of the AZL
partnership into concrete, cross-industry collaboration. By bringing together partners from across the composite value chain and using the extensive know-how and infrastructure available within AZL and its ecosystem, we enable efficient, targeted innovation on all aspects of composite technologies, from design and process validation to mechanical testing and industrial implementation.”