Fundamental tribological experiments and antifriction design of novel superconducting tilting pad bearing for liquid rocket engine

Abstract

Novel superconducting tilting pad bearing can realize the compound of superconducting magnetic force and hydrodynamic fluid-film force in liquid rocket engine and possesses the advantages of larger bearing capacity and higher stiffness. The indispensable small operational clearance for the bearing would possibly cause rubbing phenomena between superconducting stator and magnet rotor under impact loads. Three Y_1.8Ba_2.4Cu_3.4O_x bulk superconductors with different crystal domains are used to study the dry friction coefficients between superconductor and neodymium iron boron (NdFeB) magnet with nickel coating. In order to improve the fundamental tribological performance of the novel bearing, upper surface of modified superconducting tilting pad is covered by thin impregnated graphite and the nickel coating of magnet is replaced by chromium coating. Pin-on-disc experimental results indicate that the antifriction design method is effective and safe for liquid rocket engine. This study can promote the application process of novel superconducting bearing in a new generation of liquid rocket engine in China.