Analysis and Experiment of 5-DOF Decoupled Spherical Vernier-Gimballing Magnetically Suspended Flywheel (VGMSFW)

Due to the capacity of outputting both the high precision torque and the instantaneous large torque, the vernier-gimballing magnetically suspended flywheel (VGMSFW) is regarded as the key actuator for spacecraft. In this paper, a 5-DOF active VGMSFW is presented. The 3-DOF translation and 2-DOF deflection motions of the rotor are respectively realized by the spherical magnetic resistance magnetic bearings and the Lorentz magnetic bearing. The mathematical model of the deflection torque is established, and the decoupling between the 2-DOF deflections is demonstrated by the numerical analysis method. Compared with the conventional cylindrical magnetic bearings-rotor system, the spherical system is proven to eliminate the coupling between the rotor translation and deflection. In addition, a set of spherical magnetic resistance magnetic bearings with six-channel decoupling magnetic circuit are adopted to achieve the 3-DOF translation decoupling. The rotor dynamic model is derived, and the control system is established. The decoupling experiments and the torque experiments of the prototype are carried out. The results show that the decoupling among 5-DOF motions is realized and the instantaneous large torque can be obtained, which indicates that the requirements of the spacecraft can be highly satisfied by the spherical VGMSFW.