SUPERCONDUCTING BEARINGS IN FLYWHEELS

Investigations are being carried out into the use of superconducting m agnetic bearings to levitate Energy storage flywheels. In a planned pr ogram of work, Cambridge University are aiming to produce a practical bearing system for Pirouette(TM). The Pirouette(TM) system is designed to provide 5 kWh of recoverable energy which is currently recoverable at a rate of 5 kW (future revisions will provide up to 50 kW). IES (a British Nuclear Fuels subsidiary) the owners of the Pirouette(TM) mac hine have supplied Cambridge with a flywheel. This flywheel weighs > 4 0 kg and is being levitated using an Evershed-type arrangement in whic h the superconductor is being used to stabilize the interaction betwee n two magnets. To date we have demonstrated stable levitation in stati c and low speed tests in a rig designed for low speeds of rotation in air. A second rig which is currently under construction at BNFL will r un in vacuum at speeds of up to 50000 rpm. (C) 1998 Published by Elsev ier Science S.A. All rights reserved.