Motion analysis of a rotor supported by self-acting axial groove gas bearing system with double time delays

Abstract

A rotor system with double time delays supported by the high-speed self-acting gas-lubricated bearings with three-axial grooves is modeled to implement active delay control of the system. The differential transformation method is employed to solve the time-dependent compressible gas Reynolds equation due to its rapid convergence rate and minimal calculation error. Based on the precise integration method, a calculation method is proposed to analyze the dynamic responses of a gas bearing-rotor nonlinear system with time delays. The motion analysis of the self-acting gas-lubricated bearing-rotor system with double time delays is implemented by the orbit diagrams, the time series, and the phase diagrams. The influence of time delays and feedback control gains on the dynamic responses of the bearing-rotor nonlinear system is analyzed. The numerical results show that the amplitude of the responses of the system with time delays control is reduced, the motion is more stable and good control effect is achieved when the chosen feedback control gains match the time delays of the bearing-rotor system.

Load performance analysis of three‐pad fixing pad aerodynamic journal bearings with parabolic grooves

“…When the load performance of TPFPAJBs is investigated, the value of the deviation angle θ is 0°and the gas film force f y acting on the journal along the y direction is selected as the load-carrying capacity. 10 Hence, the load-carrying capacity of TPFPAJBs can be calculated by [14][15][16][17]…”

“…No investigation detailing the load performance of micro‐grooved fixing pad aerodynamic journal bearings seems to exist in the open literature. Previous studies have focused on smooth fixing pad aerodynamic journal bearings . Focusing on micro‐grooved three‐pad fixing pad aerodynamic journal bearings (TPFPAJBs), this study systematically evaluates the effect of the groove geometry on the load performance by the multi‐grid finite element method.…”

“…Previous studies have focused on smooth fixing pad aerodynamic journal bearings. [14][15][16][17] Focusing on micro-grooved three-pad fixing pad aerodynamic journal bearings (TPFPAJBs), this study systematically evaluates the effect of the groove geometry on the load performance by the multi-grid finite element method. Special attention is given to the effect of the depth, width, distance and orientation angle of the grooves on the load-carrying capacity.…”

Nonlinear dynamic response and bifurcation of asymmetric rotor system supported in axial-grooved gas-lubricated bearings

“…The influence of the nonlinear gas film forces on the stability of rotor system was investigated via analyzing the bifurcation and chaotic behaviors. We 12 proposed a calculation method coupling with the precise integration method for analyzing nonlinear dynamic behaviors of the self-acting axial groove gas bearing-rotor system with double time delays. The stability of the system can be improved via choosing the proper feedback control gains and the time delays.…”