Response of a Vertical Flexible Rotor Supported by Superconducting Bearings on Excitation Caused by the Disc Unbalance

A frequent requirement put on operation of rotating machines is minimizing energy losses and wear in the support elements. This is offered by mounting the rotors in superconducting bearings. These coupling elements consist of two parts of a permanent magnet attached to the shaft journal and of a stationary part formed by high temperature superconducting material of the second kind. The performed research was focused on analysis of vibration of vertical rotors composed of a flexible shaft and one rigid disc. The superconducting bearings are implemented in the computational model by means of a force coupling. The magnetic forces and moments acting on the shaft are determined by application of the frozen image method. Results of the analysis show that (i) amplitude of the rotor vibration induced by the disc unbalance remains sufficiently low, (ii) the load bearing capacity of the superconducting bearings is sufficiently high, and (iii) the change of the electrodynamic damping acting on the rotor disc does not induce excessive lateral oscillations. The performed study is based on computational simulations utilizing theories from the field of mechanics and electromagnetism that were experimentally verified.