The trajectory monitoring method of hydrodynamic suspension bearing based on laser-ranging technology

Rotor trajectory monitoring, essential for the stability assessment and trouble diagnosis of rotating machines, has attracted extensive attention for a long time. Nevertheless, in the case of hydrodynamic suspension micropumps, whose rotating components are wrapped in motor windings with strong electromagnetic interference, it is challenging to monitor the trajectory of the rotor, and a contactless measurement scheme is yet to be developed. In this study, we proposed a promising approach to obtain the centre location of the rotor of a hydrodynamic suspension micropump based on laser displacement sensors and built a test bench. Through experiments at multiple rotating speeds, the rotor’s displacement and velocity variations in two orthogonal directions, as well as the trajectories of the rotor, were captured and analysed, making the evaluation of the rotor’s operational stability feasible. We reveal an improvement in suspension stability by increasing the rotating speed and elaborating on the corresponding mechanism. Simultaneously, the experimental results show that the proposed method can achieve less than 1.3% relative uncertainty. In this study, we allow for high-precision contactless anti-jamming rotor trajectory monitoring at the microscale and in electromagnetically variable situations.