Dynamic optimization analysis of a stored energy motor with serious unbalanced mass distribution
The rotor-bearing system of a stored energy motor, which is composed of exciter, main generator and asynchronous motor, has typical characteristics of serious unbalanced mass distribution. According to the rotor and bearing system of the stored energy motor, dynamic performance optimization analyses are carried out by means of the finite element analysis method, to give the system optimization method and to establish the system optimization plan.
Numerical Method and Bifurcation Analysis of Jeffcott Rotor System Supported in Gas Journal Bearings
From the viewpoint of nonlinear dynamics, the stability and bifurcation of the rotor dynamical system supported in gas bearings are investigated. First, the dynamical model of gas bearing-Jeffcott rotor system is given, and the finite element method is used to approach the unsteady Reynolds equation in order to obtain gas film forces. Then, the method for stability analysis of the unbalance response of the rotor system is developed in combination with the Newmark-based direct integral method and Floquet theory. Finally, a numerical example is presented, and the complex behaviors of the nonlinear dynamical system are simulated numerically, including the trajectory of the journal and phase portrait. In particular, the stabilities of the system's equilibrium position and unbalance responses are studied via the orbit diagram, phase space, Poincare mapping, bifurcation diagram, and power spectrum. The results show that the numerical method for solving the unsteady Reynolds equation is efficient, and there exist a rich variety of nonlinear phenomena in the system. The half-speed whirl encountered in practice is the result from Hopf bifurcation of equilibrium, and the numerical method presented is available for the stability and bifurcation analysis of the complicated gas film-rotor dynamic system.
Analysis of Gas-Lubricated Foil Journal Bearings
Evaluation des caracteristiques de fonctionnement d'un palier a gaz utilisant comme surface portante une feuille metallique souple supportee par un systeme elastique. Analyse donnant l'influence des differentes variables de construction et de fonctionnement sur le comportement du palier, les solutions etant presentees sous forme de graphiques ou de tableaux. Caracteristiques de conception souhaitables quant au depart de l'arc, au choix de l'angle de charge, au nombre de patins, et au degre de souplesse