Flywheel for energy storage, phase 2

The purpose of the project is to manufacture, test and verify the design of the two 1 kWh flywheel rotors for energy storage. The basic design and the necessary investigations on system requirements, materials and manufacturing process has been performed in a previous project, and the present project covers the manufacturing of the prototype aggregate, including two variants of the rotor, as well as the verification of the systems performance. The design drawings for the rotor, bearing, housing and support frame have been produced after initial consultations with potential manufacturers. Especially the tight tolerances for some parts and budget restrictions posed problems, which had to be solved in close collaboration with the final manufacturer of the individual parts. The two carbon-fibre/epoxy composite flywheel rims and the connection element between rim and shaft are manufactured by filament winding. After balancing of the rotors and assembling of all parts, the systems performance were initial verified at low-velocity (<6000 rpm) in the laboratory and different necesssary corrections and modifications performed. Tests to higher velocities were next conducted in a safe vault. It has so far not been possible to obtain the projected 36.000 rpm, as the bearing system failed several times at app. 18.000 rpm. Neither rotor nor the housing and other equipment suffered any damage