IDENTIFICATION OF THE OIL-FILM DYNAMIC COEFFICIENTS IN A ROTOR-BEARING SYSTEM WITH A HYDRODYNAMIC THRUST BEARING

2000 ◽  
Vol 236 (4) ◽  
pp. 733-740 ◽  
Author(s):  
P.L. JIANG ◽  
L. YU
Keyword(s):  
Thrust Bearing ◽  
Oil Film ◽  
Dynamic Coefficients ◽  
Rotor Bearing ◽  
Bearing System

Nonlinear Dynamics of Flexible Rotors Supported on Journal Bearings—Part I: Analytical Bearing Model

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Mohammad Miraskari ◽  
Farzad Hemmati ◽  
Mohamed S. Gadala
Keyword(s):  
Journal Bearing ◽  
Nonlinear Coefficient ◽  
Journal Bearings ◽  
Flexible Rotor ◽  
Dynamic Coefficients ◽  
Flexible Rotors ◽  
Rotor Bearing ◽  
Bearing Force ◽  
Derivatives Of ◽  
Bearing System

To determine the bifurcation types in a rotor-bearing system, it is required to find higher order derivatives of the bearing forces with respect to journal velocity and position. As closed-form expressions for journal bearing force are not generally available, Hopf bifurcation studies of rotor-bearing systems have been limited to simple geometries and cavitation models. To solve this problem, an alternative nonlinear coefficient-based method for representing the bearing force is presented in this study. A flexible rotor-bearing system is presented for which bearing force is modeled with linear and nonlinear dynamic coefficients. The proposed nonlinear coefficient-based model was found to be successful in predicting the bifurcation types of the system as well as predicting the system dynamics and trajectories at spin speeds below and above the threshold speed of instability.

Stability analysis of rubber-supported thrust bearing in a rotor-bearing system used in marine thrusters under disturbing moments

2020 ◽  
Vol 151 ◽  
pp. 106356 ◽  
Author(s):  
Fangxu Sun ◽  
Xianbiao Zhang ◽  
Yingsan Wei ◽  
Xing Wang ◽  
Dong Wang
Keyword(s):  
Stability Analysis ◽  
Thrust Bearing ◽  
Rotor Bearing ◽  
Bearing System

Modelling and Analysis of the Dynamic Behavior of an Active Journal Bearing

1994 ◽  
Author(s):  
Linxiang Sun ◽  
Janusz M. Krodkiewski ◽  
Nong Zhang
Keyword(s):  
Pressure Distribution ◽  
Reynolds Equation ◽  
Hydrodynamic Pressure ◽  
Chamber Pressure ◽  
Oil Film ◽  
Simulation Based ◽  
Rotor Bearing ◽  
New Type ◽  
The Stability ◽  
Bearing System

Modelling and analysis of a rotor-bearing system with a new type of active oil bearing are presented. The active bearing basically consists of a flexible sleeve and a pressure chamber. The deformation of the sleeve can be controlled by the chamber pressure during the operation, and so can the pressure distribution of the oil film. Finite Element Methods (FEMs) and the Guyan condensation technique were utilised to create mathematical models for both the rotor and the flexible sleeve. The hydrodynamic pressure distribution of the oil film, for the instantaneous positions and velocities of the flexible sleeve and rotor, was approximated by Reynolds equation. The influence of the chamber pressure on the stability of the rotor system was investigated by numerical simulation based on the nonlinear model. The results showed that the stability of the rotor-bearing system can be improved effectively by implementation of the active bearing.

Non-linear dynamic behaviour of rotor—bearing system trained by bevel gears

2008 ◽  
Vol 222 (4) ◽  
pp. 617-627 ◽  
Author(s):  
M Li
Keyword(s):  
Equilibrium Points ◽  
Rotor System ◽  
Design Stage ◽  
Oil Film ◽  
Bevel Gears ◽  
Linear Dynamic ◽  
Non Linear ◽  
Rotor Bearing ◽  
Stability And Bifurcations ◽  
Bearing System

The vibrations of parallel geared rotor—bearing system have been intensively discussed; however, little attention has been paid to the dynamic analysis of angled bevel-geared system supported on journals. In the present work, the non-linear dynamics of a bevel-geared rotor system on oil film bearings is studied. First, the dynamic model is developed under some assumptions, such as rigid rotors, short-bearings, small teeth errors, and so forth. Then, the non-linear dynamic behaviours of both the balanced and unbalanced rotor system are analysed, respectively, in which the equilibrium points, limit cycles, their stability, and bifurcations are paid more attention. Numerical results show that in the bevel-geared rotor system under the action of non-linear oil film forces there exists a series of complex non-linear dynamic phenomena of rotor orbits, such as Hopf bifurcation, torus-doubling bifurcation, and jump phenomenon. All these features can help us to understand the dynamic characteristics of bevel-geared rotor—bearing system at design stage and during running period. Finally, some concerned problems during the investigation are also present.

Sign in / Sign up

Export Citation Format

Share Document