The Effect of the 150-Degree Partial Bearing on Rotor-Unbalance Vibration

1964 ◽  
Vol 86 (2) ◽  
pp. 337-345 ◽  
Author(s):  
P. C. Warner ◽  
R. J. Thoman
Keyword(s):  
Force Transmission ◽  
Oil Whip ◽  
Rotor Bearing ◽  
Unbalance Force ◽  
Stability Limits ◽  
Dynamic Unbalance ◽  
Bearing System

The effect of a centrally loaded 150-deg partial bearing on the transmission of unbalance force is determined for a simple, symmetrical rotor-bearing system considering both static and dynamic unbalance. Design curves giving force transmission, mass and journal vibration, and oil-whip stability limits are included.

Reliability Sensitivity Analyses for Oil Whip in Rotor-Bearing System

2012 ◽  
Vol 538-541 ◽  
pp. 1967-1970
Author(s):  
Chang Qing Su ◽  
Yi Yu Sun ◽  
Le Xin Li
Keyword(s):  
High Speed ◽  
Sensitivity Analyses ◽  
Analysis Method ◽  
Random Parameters ◽  
Work Condition ◽  
Oil Whip ◽  
Reliability Sensitivity ◽  
Rotor Bearing ◽  
The Common ◽  
Bearing System

Oil whip phenomenon is the common fault in rotor-bearing system. The reason why oil whip happens often has been researched in high-speed rotor-bearing system. But in practice engineering, due to the requirement of work condition, oil whip cannot be avoided all the time in rotor-bearing system. The paper is based on the relation criterion of oil whip happens in rotor-bearing system, the reliability mode and system reliability of oil whip are defined, and the reliability analysis method for avoiding oil whip in rotor-bearing system is carried out. The effect on reliability sensitivity of random parameters is studied. Numerical results are also presented and discussed.

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.

Transverse Vibrations of a General Cracked-Rotor Bearing System

1982 ◽  
Vol 104 (2) ◽  
pp. 345-355 ◽  
Author(s):  
T. Inagaki ◽  
H. Kanki ◽  
K. Shiraki
Keyword(s):  
Bending Moment ◽  
Step Function ◽  
Analysis Model ◽  
State Response ◽  
Expansion Technique ◽  
Rotor Bearing ◽  
Small Test ◽  
Unbalance Force ◽  
Numerical Calculation Method ◽  
Bearing System

In this study, the steady state response to the gravity and the unbalance force, and the major natural vibration of a general rotor bearing system with the open or open-close type crack, is analyzed along the iterative numerical calculation method (the transfer matrix method). The open-close type crack is idealized as a step function of the bending moment. The nonlinear equations are linearized by using the Fourier expansion technique, and its solutions are given approximately with the static deflection, the once/rev. vibration, and the twice/rev. vibration. The analyzed calculated method is confirmed by comparing the calculations with the experiments for a small test rotor. The rotor bearing system model in this method is as accurate as the usual numerical rotor dynamic analysis model, and also the required procedures for the calculation are almost the same.

scholarly journals An Identification Method for the Unbalance Parameters of a Rotor-Bearing System

2016 ◽  
Vol 2016 ◽  
pp. 1-9
Author(s):  
Wengui Mao ◽  
Guiping Liu ◽  
Jianhua Li ◽  
Jie Liu
Keyword(s):  
Identification Problem ◽  
Convolution Integral ◽  
Test Rig ◽  
Identification Method ◽  
Rotor Bearing ◽  
Force Reconstruction ◽  
Deconvolution Problem ◽  
Unbalance Force ◽  
The Time Domain ◽  
Bearing System

This paper is to be submitting an identification method for the unbalance parameters of a rotor-bearing system. In the method, the unbalance parameters identification problem is formulated as the unbalance force reconstruction which belongs to solving deconvolution problem, in which the unbalance force is expressed in the time domain. The unbalance response is expressed by the convolution integral of Green’s function and the unbalance force. In order to avoid the unstable solution arising from the noisy responses and the deconvolution, a regularization method is adopted to stabilize the solution. Meanwhile, a searching of the sensitive measured point has also been carried out to confirm the robustness of the method. Numerical example and a test rig have been used to illustrate the proposed method.

scholarly journals Transmissibility Analysis of a Regenerated Rotor System

2021 ◽  
Vol 9 (8) ◽  
pp. 1102-1107
Author(s):  
Akanksha Dhurvey
Keyword(s):  
High Speed ◽  
Critical Speed ◽  
Rotor System ◽  
Jet Engines ◽  
Simply Supported ◽  
Rotor Bearing ◽  
Unbalance Force ◽  
Force Transmissibility ◽  
Very High ◽  
Bearing System

Abstract: The aim of this paper is to represents a dynamic behavior of rotor bearing system wirth simply supported beam for three different position disc. rotating machinery such as compressors, turbines, pumps, jet engines, turtobo chargers, etc. are subject to vibrations. rotating machines are operated in very high speed and they are subjected to some unbalance force due to vibration from that machine pass to the foundation of machine.so the analysis of the dynamics parameter of rotor it is important to determine force transmissibility, natural frequency, critical speed and amplitudes of rotor system. Keywords: force transmissibility, vibration, critical speed, rotor bearing system etc.

Effects of Shaft Shape Errors on the Dynamic Characteristics of a Rotor-Bearing System

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Fangxu Sun ◽  
Xianbiao Zhang ◽  
Xing Wang ◽  
Zhenzhong Su ◽  
Dong Wang
Keyword(s):  
Dynamic Characteristics ◽  
Computing Time ◽  
Quantitative Relationship ◽  
System Stability ◽  
Rotating Speed ◽  
Oil Whip ◽  
Rotor Bearing ◽  
Shape Errors ◽  
Reaction Forces ◽  
Bearing System

Effects of shaft shape errors are studied on dynamic characteristics of a rotor-bearing system. Stability characteristics of the cylindrical journal bearing are studied. It is shown that the rotating speed at which the oil whip occurs increases when the shape errors exit. And, there is a threshold speed of the bearing with shaft shape errors; before the speed is increased to the threshold, orbits of the center of the journal decrease, and when the speed exceeds the threshold, the orbits increase dramatically and oil whip appears. Furthermore, the quantitative relationship between shaft shape errors and bearing reaction forces of the rotor-bearing system is obtained, which is verified by experiments using rotors with different machining precisions. In order to reduce computing time, variational principle is applied when solving Reynolds’ equation.

scholarly journals Analysis of Vibration Characteristics for a Rotor-Bearing System Using Distributed Spring and Damper Model

1995 ◽  
Vol 1 (3-4) ◽  
pp. 277-284 ◽  
Author(s):  
D. C. Han ◽  
S. H. Choi ◽  
Y. H. Lee
Keyword(s):  
Shape Function ◽  
Quadratic Function ◽  
Journal Bearings ◽  
Vibration Characteristics ◽  
Distributed Model ◽  
System A ◽  
Rotor Bearing ◽  
The Stability ◽  
Stability Limits ◽  
Bearing System

In this paper, we modelled the journal beatings as distributed springs and dampers to investigate the influence of beating width on the vibration characteristics of a rotor-beating system. A quadratic function is used as a shape function for hydrodynamic journal bearings. And a trapezoidally or a quadratically distributed model is used as a shape function for hydrostatic journal bearings. A finite element method is applied for analyzing the vibration characteristics of a rotor-bearing system.Dimensionless governing equations are derived for a uniform rotor supported by two journal bearings, which are modelled as point supported or distributed springs and dampers. For these models, natural frequencies for various beating length ratios and stiffness ratios between the bearing and the shaft are calculated and compared with each other. Then the stability limits of a rotor supported by two cylindrical journal beatings are calculated for the point supported or distributed springs and dampers.

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