Nonlinear Dynamic Analysis of a Flexible Rotor System with a Combination of Fixed-Tilting Pads Journal Bearing Supports
LU Yan-Jun1, YU Yang-Bing1, ZHANG Yong-Fang2, WANG Dong1, YU Lie3
(1 School of Mechanical and Instrumental Engineering，Xi’an University of Technology，Xi’an, Shaanxi 710048，People’s Republic of China)(2 School of Printing and Packaging Engineering，Xi’an University of Technology，Xi’an, Shaanxi 710048，People’s Republic of China)(3 Institute of Mechatronics and Information Systems, Xi’an Jiaotong University, Xi’an, Shaanxi 710049, People’s Republic of China)
Abstract：Abstract： Based on the Reynolds equation with Reynolds boundary conditions, the Castelli method was employed to solve the Reynolds equation for oil lubrication upon bearings. By doing so, a profile of nonlinear oil film force of single pad journal bearings is established. According to the structure of combination journal bearings, nonlinear oil film force of combination journal bearing is obtained by retrieval, interpolation, and assembly techniques. As for symmetrical flexible Jeffcott rotor system supported by combination journal bearings, the nonlinear motions of the center of the rotor are calculated by self-adaptive Runge-Kutta method and Poincaré mapping during different rotational speed tests under different pivot ratio. Numerical results show that the performance of system becomes slightly better when the pivot ratio changes from 0.5 to 0.6, and reveal periodic, period-doubling, quasi-periodic motion, etc. nonlinear behaviors.
2011, Vol. 30 
