Variation Analysis of Vibration Phase Difference between the Horizontal and Vertical Directions during Run-up Process

Abstract

Unbalance excitation can cause rotor vibrations in both horizontal and vertical directions. The vibration phase difference between the two directions during the run-up process under unbalance excitation is analyzed. The change of vibration phase difference with rotational speed is studied. Results show that, the vibration phase difference changes in a large range during the run-up process, which is related to bearing anisotropy, system damping, natural frequency and rotational speed. When the system parameters such as damping and natural frequency are determined, the vibration phase difference is a function of rotational speed. It changes greatly when the working speed is close to the critical speed of each direction. Based on the vibration amplitudes and phase difference between the two directions, the damage of cross-section vibration to the equipment can be evaluated accurately.