Modified oil film force model for investigating motion characteristics of rotor-bearing system

Abstract

The oil film force induced from bearings has a direct influence on the stable operation of a rotor system because the change in motion characteristics will lead to variation of the oil film force. An accurate oil film force model is therefore critical to predict the motion characteristic state of a rotor system. The linear oil film force model and the Muszynska model are employed by many scholars to predict linear force and nonlinear oil film force respectively. When the rotor system has a larger eccentricity ratio, the changing law of the rotor system is not predicted by the Muszynska model. In this paper an improved oil film force model is developed for the motion changing law. This model is based on short bearing assumption with the turbulence effect and rotor motion equation included. The motion law is well described by this model. In particular the dynamic characteristics can be described well by the modified model. To verify the simulation results of the modified model, an experiment is carried out. Finally, there is a comparison between theoretical and experimental results and it is found that the theoretical results are in good agreement with the experimental results. This paper provides a reference for further research of the motion changing law of rotor systems.

Effect of the unbalanced magnetic pull force and oil-film force on nonlinearity of a dual-rotor bearing system

“…On this basis, the effects of the change in the rotating speed and damping ratio on the dynamic characteristics of the rotor system are studied theoretically in detail. He and Jing 18 proposed a modified oil film force model to study the oil film pressure law of the bearing of the rotor system. Hu et al 19 investigated the nonlinear dynamic behaviours of an asymmetric double-disk rotor-bearing system considering rub-impact and oil-film instability using Numerical and experimental methods.…”

Nonlinear dynamic properties of disk-bolt rotor with interfacial cutting faults on assembly surfaces

“…Firstly, a 3D disk-bolt rotor with interfacial cutting fault should be built. The conventional rotor models like rigid rotors (El-Saeidy and Sticher, 2010; Giovanni, 2015), flexible rotors (Gong and Cao, 2010; He and Jing, 2014; Wang and Meng, 2005), and one-dimensional finite element rotors (Choi and Yang, 2000; El-Saeidy, 1998) are proved to be very useful to analyze the rotor dynamic features. However, the 3D machining fault with specific shape and size cannot be considered in these simple models.…”