Nonlinear Analysis of Rotor-Stator-Bearing System Unsteady Oil Film Force

2013 ◽  
Vol 341-342 ◽  
pp. 395-399
Author(s):  
Gui Zhen Liu ◽  
Ying Yu ◽  
Bang Chun Wen
Keyword(s):  
Dynamics Model ◽  
Oil Film ◽  
Oil Whip ◽  
Film Instability ◽  
Oil Whirl ◽  
Amplitude Spectra ◽  
Axis Orbit ◽  
Speed Change ◽  
Effective Diagnosis ◽  
Bearing System

According to the LaGrange energy equation, the establishment of the unsteady oil film force of the rotor - stator - bearing system dynamics model, the application of numerical method, the system with the speed change time domain waveforms, amplitude spectra and Axis Orbit, the results show that: the unsteady oil film force and speed of change is closely related to changes in the process of oil film force oil whirl Oil Whip. Provide a theoretical basis for effective diagnosis of rotor - stator - bearing oil film instability fault research.

Analysis and Experimental Study on Stability of Nonlinear Rotor-Bearing System

2011 ◽  
Vol 236-238 ◽  
pp. 2626-2629
Author(s):  
Wei Dong Gu ◽  
Yong Liang Wang ◽  
Bo Fang ◽  
Zhan Sheng Liu ◽  
Wen Hu Huang
Keyword(s):  
Finite Element Method ◽  
Experimental Study ◽  
Test Rig ◽  
Model Simulations ◽  
Oil Whip ◽  
Film Instability ◽  
Oil Whirl ◽  
Rotor Bearing ◽  
Practical Model ◽  
Bearing System

The paper established the model of the practical Model test rig rotor-bearing system using finite element method, and discusses the phenomena of oil whirl and oil whip occurred in fluid lubricated bearing. The characteristics of stability of the nonlinear rotor-bearing system were numerically studied under different unbalance and different parameter of bearings, the model simulations are compared with measurements at the test rig, which can provide the theoretical reference for forecasting malfunction of oil film instability.

The Fault Analysis and Research of Turbine Generator Sliding Bearing Oil Film Instability

2014 ◽  
Vol 915-916 ◽  
pp. 198-202
Author(s):  
Guo Dong Han ◽  
Zhang Qin Wu ◽  
Shu Ting Wan ◽  
Zhan Jie Lv ◽  
Rong Hai Liu ◽  
...  
Keyword(s):  
Spectral Characteristics ◽  
Fault Analysis ◽  
Turbine Generator ◽  
Sliding Bearing ◽  
Oil Film ◽  
Oil Whip ◽  
Film Instability ◽  
Oil Whirl ◽  
Whirl Speed ◽  
The Time Domain

This article are discussed Sliding Bearing for Turbine instability failure research status in detail; Gives the theoretical analysis On sliding bearing oil film instability failure mechanism, to further explore the oil whirl and oil whip manifestations and signal spectral characteristics. And analysis of the oil whirl speed changes the vibration characteristics of typical regions, given the time-domain waveform oil whirl and oil whip axis trajectory. Details of the turbine generator film and the main reason for the instability factors and made a film instability fault governance approach. It helped for Fault Diagnosis of Turbine film and achieving security and stability of Turbine provides technical reference.

Effects of eccentric phase difference between two discs on oil-film instability in a rotor–bearing system

2013 ◽  
Vol 41 (1-2) ◽  
pp. 526-545 ◽  
Author(s):  
Hui Ma ◽  
Hui Li ◽  
Xueyan Zhao ◽  
Heqiang Niu ◽  
Bangchun Wen
Keyword(s):  
Phase Difference ◽  
Oil Film ◽  
Film Instability ◽  
Rotor Bearing ◽  
Bearing System

Research on Circumferential Fluid Pressure Distribution and Whirl Stability of Rotor-Bearing System

2008 ◽  
Author(s):  
Ce Chen ◽  
JinFu Yang ◽  
ChaoQun Nie ◽  
Ying Cui ◽  
DaRen Yu ◽  
...  
Keyword(s):  
Pressure Distribution ◽  
Fluid Pressure ◽  
Pressure Change ◽  
Eccentricity Ratio ◽  
Oil Film ◽  
Oil Whip ◽  
Oil Whirl ◽  
Bearing Load ◽  
Whirl Speed ◽  
Oil Film Pressure

This paper presents a theoretical analysis of the mechanism of oil whirl, oil whip, and hysteresis in oil whip. A qualitative analysis of the interrelation between whirl frequency, natural frequency, and eccentricity ratio versus speed was conducted using the rotor-bearing load balance equation. By analyzing the interrelation among whirl speed, eccentricity ratio versus speed, rotating speed, oil supply pressure and bearing load, and observing the oil-film load circumferential fluid pressure distribution in the three phases of oil-film load attenuation, instability transition, and oil-film load instability, it was found that in the whirl instability transition phase, the amplitude of rotor whirl speed exceeds half the value of rotor rotation speed, which causes the pressure change in the oil convergent wedge to change from positive to negative, and the pressure change in the divergent wedge to change from negative to positive, and the change in oil-film pressure distribution causes the instability of oil whirl; These changes in oil film pressure distribution are the indicator of oil whirl instability. An experimental study on the whirl instability in a pump supported on fluid film bearings is also presented in this paper to validate the theoretical approach.

Experimental Research on Nonlinear Vibration Characteristics of Rotor Bearing System With Coupling Fault of Rub-Impact and Oil Whirl

2005 ◽  
Author(s):  
Changli Liu ◽  
Yimin Zhang ◽  
Qing Kai Han ◽  
Bangchun Wen
Keyword(s):  
Nonlinear Vibration ◽  
Experimental Research ◽  
Vibration Characteristics ◽  
Rotor System ◽  
Harmonic Vibration ◽  
Oil Film ◽  
Oil Whirl ◽  
Rotor Bearing ◽  
Coupling Fault ◽  
Bearing System

An experimental rotor rig was developed to investigate nonlinear vibration characteristics of rotor bearing system with coupling fault of rub-impact and oil whirl. It was found that when the effect of oil film force on a rub-impact rotor system is comparatively weak, the rotor/stator rub-impact will cause the system to give rise to sub- and super-harmonic vibration components. In a rub-impact rotor system with oil whirl fault, super-harmonic vibration components were excited, when rotor/stator rub-impact happens before oil film whirl because of small rotor/stator clearance. When the rotor/stator clearance is comparatively large, the rub-impact happens after oil film whirl, and the effect of rub-impact on the rotor system will be very weak.

scholarly journals Coupling Analysis of Dynamics and Oil Film Lubrication on Rotor - Floating Bush Bearing System

2011 ◽  
Vol 5 (3) ◽  
pp. 461-473 ◽  
Author(s):  
Mizuho INAGAKI ◽  
Atsushi KAWAMOTO ◽  
Takanori ABEKURA ◽  
Atsushi SUZUKI ◽  
Jan RÜBEL ◽  
...  
Keyword(s):  
Coupling Analysis ◽  
Oil Film ◽  
Analysis Of Dynamics ◽  
Bearing System ◽  
Film Lubrication

A Theory of Oil Whip

1959 ◽  
Vol 26 (2) ◽  
pp. 189-198
Author(s):  
Yukio Hori
Keyword(s):  
Negative Pressure ◽  
Higher Order ◽  
Inertia Effect ◽  
Oil Viscosity ◽  
Oil Film ◽  
Oil Whip

Abstract Oil whip was investigated theoretically and experimentally. In the paper it is shown that the inherent instability of the rotor in previous theories can be avoided by assuming zero pressure in place of negative pressure in the oil film and that the “inertia effect” in occurrences of oil whip can be understood by distinguishing small vibrations and large vibrations of the rotor. It is also shown that oil whip of higher order and the effect of oil viscosity on amplitude of oil whip give possible causes of some peculiar phenomena.

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.

Sign in / Sign up

Export Citation Format

Share Document