Magnetically Levitated Reaction Wheel for Space Application

The content of the present study is the feasibility asseasment of a reaction wheel on active magnetic bearings (AMB) to be followed by the design of a fully operational engineering model I, which is presently under construction. The stress is laid mainly on the demonstration that a small, simple reaction wheel on AMB can be built and operated reliably with power requiremems which are not in excess than those characteristic of conventional units. A reaction wheel ks usually a part of a complex system whose task is the attitude control of a spacecraft and in some cases also the storage of energy in the form of kinetic energy in the rotor. Here the work is concentrated only on the reaction wheel component, intended as a torque actuator. No attempt to address the problems related to the global system or to the possibility of using the reaction wheel as an energy storage device is performed. AMB technology is at present a well known technology in high speed rotating machinery. Several prototypes of machines of various kinds in which the rotor is magnetically suspended have been built and in some cases are on the market. Several applications of reaction wheels have been studied and many reaction wheels operating on AMB have been built, starting from the seventies 2. The present study is intended to address some specific problems, mostly related with low power consumption, high system integration and design compactness.