E-bike motors: The trend towards electric bicycles continues. According to the German Bicycle Industry Association (ZIV), e-bikes already accounted for 48 percent of all bicycle sales in 2022, and this figure is still rising. There is an increasing variety of models, both from well-known brands and from smaller manufacturers bringing new innovations to the market. However, repairs in workshops, especially for batteries and motors, are often technically and economically unfeasible. This can lead to a situation where the failure of a single component of an e-bike results in total loss.
Researchers at the Fraunhofer IPA investigated why used e-bike motors cannot be industrially refurbished. In a project called " AddRE-Mo ," funded by the German Federal Ministry of Education and Research (BMBF), they collaborated with partners to examine the technical feasibility of remanufacturing electric bicycle motors. The entire remanufacturing process chain—from non-destructive disassembly through cleaning, testing, reconditioning or replacement with new parts, to assembly—was examined, and its ecological and economic potential was analyzed. The researchers also investigated the use of additive manufacturing processes and suitable combinations of processes and materials for producing durable and robust replacement parts.
E-bike motors: from disassembly to reassembly
In the first step, the team investigated the failure probability of e-bike motors from established manufacturers. They then examined whether and under what conditions wear-prone spare parts such as gears and torque arms could be additively manufactured. The necessary data for 3D printing was obtained either through 3D modeling or 3D digitization, depending on the geometry of the components. They then selected suitable materials and additive manufacturing processes. Together with the companies cirp and Electric Bike Solutions, Fraunhofer IPA then manufactured the components and tested their service life, noise levels, and temperature resistance in specially developed test benches and under real-world loads. In total, more than 120 parts made from 20 different materials were produced using a 3D printer. High-speed sintering, a special process for manufacturing or modifying materials, proved particularly promising in combination with the plastic polyamide 12 (PA12). The project results are summarized in the study "Additive Remanufacturing in the E-Bike Industry," which can be downloaded here free of charge .
E-bike motors: sustainability and resource efficiency
Through the reassembly and the test under real conditions, the project partners were able to prove the technical feasibility and durability. The research results showed that individual components such as gear wheels can be additively manufactured and used sustainably. The bicycle motor produced by remanufacturing corresponds to a newly manufactured motor in terms of quality and also includes the same guarantee. An important aspect was also the ecological evaluation of the remanufacturing process in comparison to new manufacture. By using additive manufacturing, resource consumption in the electric bicycle industry can be reduced by up to 90 percent, measured in terms of the impact on the climate in kilogram CO2 equivalents. The economic savings potential for comparable components is usually around 30 to 40 percent compared to buying a new electric motor. This also offers great potential for manufacturers of electric motors.
[blog specific=”160878″ posts_per_page=”30″ taxonomy=”post_tag” order=”desc”]Learning factory RemanLab reopened in Bayreuth
To leverage the project's results in the long term, the process chain for remanufacturing electric bicycle motors will be implemented and demonstrated in the new Remanufacturing Learning Center, the RemanLab, at the Fraunhofer IPA in Bayreuth. The RemanLab will open on May 23, 2023. In this realistic learning environment, which includes all necessary test benches, companies will gain insights into the future of sustainable production. Knowledge about the complexity of the remanufacturing process will be conveyed using concrete examples, from incoming inspection through disassembly, cleaning, testing, reconditioning, and reassembly to final inspection. The RemanLab demonstrates how digital technologies and automation can revolutionize the remanufacturing not only of electric motors, but also of small electrical appliances and other products. The RemanLab will be presented in the Innovation Zone at the ReMaTec trade fair in Amsterdam from June 27 to 29, 2023.