Research on Dynamic Characteristic and Experiments of Double-Disc Rotor System with Oil Film Support

2012 ◽  
Vol 442 ◽  
pp. 235-239
Author(s):  
Chao Feng Li ◽  
Jie Liu ◽  
Qin Liang Li ◽  
Bang Chun Wen
Keyword(s):  
Dynamic Characteristic ◽  
Period Doubling ◽  
Continuous System ◽  
Rotor System ◽  
Small Eccentricity ◽  
Oil Film ◽  
Rotor Bearing ◽  
Calculation Results ◽  
Bifurcation Solution ◽  
Bearing System

Multi-DOF model of double-disc rotor-bearing system taking oil film support into account is established, and Newmark method is also applied to dynamic response of continuous system. To simplify the calculation in double-disc eccentric situation, the research aims at time domain, frequency response and bifurcation solution, simultaneously qualitative experiments are also carried out on the experiment bench. Experiments show that the numerical algorithm and calculation results are credible. The conclusions conclude: For the rotor system shown in the paper, with the other parameters constant, small eccentricity system is prone to appear quasi-periodic instability, but for big eccentricity system it is period-doubling instability, and the instability speed will increase with eccentricity enlargement; initial eccentric phase has severe effects on the dynamic characteristic of system, so it is worth studying it more in depth. This method and results in this paper provides a theoretical reference for stability analysis and vibration control in more complex relevant rotor-bearing system.

scholarly journals Nonlinear Dynamic Analysis of Rotor Rub-Impact System

2019 ◽  
Vol 2019 ◽  
pp. 1-20
Author(s):  
Youfeng Zhu ◽  
Zibo Wang ◽  
Qiang Wang ◽  
Xinhua Liu ◽  
Hongyu Zang ◽  
...  
Keyword(s):  
Periodic Motion ◽  
Chaotic Motion ◽  
Nonlinear Dynamic Analysis ◽  
Period Doubling ◽  
Time History ◽  
Rotor System ◽  
Quasiperiodic Motion ◽  
Rotor Bearing ◽  
Motion Period ◽  
Bearing System

A dynamic model of a double-disk rub-impact rotor-bearing system with rubbing fault is established. The dynamic differential equation of the system is solved by combining the numerical integration method with MATLAB. And the influence of rotor speed, disc eccentricity, and stator stiffness on the response of the rotor-bearing system is analyzed. In the rotor system, the time history diagram, the axis locus diagram, the phase diagram, and the Poincaré section diagram in different rotational speeds are drawn. The characteristics of the periodic motion, quasiperiodic motion, and chaotic motion of the system in a given speed range are described in detail. The ways of the system entering and leaving chaos are revealed. The transformation and evolution process of the periodic motion, quasiperiodic motion, and chaotic motion are also analyzed. It shows that the rotor system enters chaos by the way of the period-doubling bifurcation. With the increase of the eccentricity, the quasi-periodicity evolution is chaotic. The quasiperiodic motion evolves into the periodic three motion phenomenon. And the increase of the stator stiffness will reduce the chaotic motion period.

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.

scholarly journals Nonlinear Vibration of a Continuum Rotor with Transverse Electromagnetic and Bearing Excitations

2012 ◽  
Vol 19 (6) ◽  
pp. 1297-1314 ◽  
Author(s):  
Haiyang Luo ◽  
Yuefang Wang
Keyword(s):  
Nonlinear Vibration ◽  
Periodic Motion ◽  
Primary Resonance ◽  
Period Doubling ◽  
Time History ◽  
Oil Film ◽  
Rotor Bearing ◽  
Transverse Electromagnetic ◽  
The Stability ◽  
Bearing System

The nonlinear vibration of a rotor excited by transverse electromagnetic and oil-film forces is presented in this paper. The rotor-bearing system is modeled as a continuum beam which is loaded by a distributed electromagnetic load and is supported by two oil-film bearings. The governing equation of motion is derived and discretized as a group of ordinary differential equations using the Galerkin's method. The stability of the equilibrium of the rotor is analyzed with the Routh-Hurwitz criterion and the occurrence of the Andronov-Hopf bifurcation is pointed out. The approximate solution of periodic motion is obtained using the averaging method. The stability of steady response is analyzed and the amplitude-frequency curve of primary resonance is illustrated. The Runge-Kutta method is adopted to numerically solve transient response of the rotor-bearing system. Comparisons are made to present influences of electromagnetic load, oil-film force and both of them on the nonlinear vibration response. Bifurcation diagrams of the transverse motion versus rotation speed, electromagnetic parameter and bearing parameters are provided to show periodic motion, quasi-periodic motion and period-doubling bifurcations. Diagrams of time history, shaft orbit, the Poincaré section and fast Fourier transformation of the transverse vibration are presented for further understanding of the rotor response.

Research on Periodic Motion Stability of Multi-DOF Rotor-Bearing System with Crack Fault

2011 ◽  
Vol 148-149 ◽  
pp. 3-6 ◽  
Author(s):  
Chao Feng Li ◽  
Qin Liang Li ◽  
Jie Liu ◽  
Bang Chun Wen
Keyword(s):  
Stability Analysis ◽  
Vibration Control ◽  
Shooting Method ◽  
Crack Depth ◽  
Continuous System ◽  
Oil Film ◽  
Rotor Bearing ◽  
The Stability ◽  
The Impact ◽  
Bearing System

Multi-DOF model of double-disc rotor-bearing system taking crack and oil film support into account is established, and the continuation shooting method combined with Newmark is also applied to stability analysis of continuous system. This paper mainly studied the variation law of five parameters domain in crack depth and location, then a number of conclusions are found: first, it’s feasible to study the stability of nonlinear rotor-bearing system with crack faults using FEM; secondly, the crack depth and location has a certain impact on instability speed, but the impact is not great and owns its certain law. As the crack depth and location is getting close to the middle position of rotor, due to its impact on the oil film support, the instability speed of system increases. This method and results in this paper provides a theoretical reference for stability analysis and vibration control in more complex relevant rotor-bearing system with crack fault.

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.

Stability of Two-Span Rotor-Bearing System with Coupling Faults of Crack and Rub-Impact

2007 ◽  
Vol 353-358 ◽  
pp. 2501-2504
Author(s):  
Yue Gang Luo ◽  
Song He Zhang ◽  
Xiao Dong Liu ◽  
Bang Chun Wen
Keyword(s):  
Floquet Theory ◽  
Period Doubling ◽  
Rotor System ◽  
Failure Diagnosis ◽  
Coupling Faults ◽  
Rotor Bearing ◽  
Set Up ◽  
The Stability ◽  
Shooting Algorithm ◽  
Bearing System

A dynamic model was set up for the two-span rotor–bearing system with coupling faults of crack and rub-impact. Using the continuation-shooting algorithm for periodic solution of nonlinear non-autonomous system, the stability of the system periodic motion was studied by the Floquet theory. The unstable form of the rotor system with coupling faults is Hopf bifurcation when the depth of crack is smaller. The influence to the response of the system increased along with the depth of crack, the unstable form of the rotor system with coupling faults is period-doubling bifurcation. The conclusions provide theoretic basis reference for the failure diagnosis of the rotorbearing system.

Evaluation of Oil Bearing Supported Rotors Coupled by Flexible Coupling

2009 ◽  
Author(s):  
Choong Hyun Kim ◽  
Kyeong Soo Lee ◽  
Yong-Bok Lee
Keyword(s):  
Dynamic Characteristics ◽  
Rotor System ◽  
Analytical Evaluation ◽  
Flexible Coupling ◽  
Oil Film ◽  
Mechanical Coupling ◽  
Rotor Bearing ◽  
Bearing System

In this study, analytical evaluation of dynamic characteristics of the mechanical coupling and its effect on the coupled rotor-bearing system are presented. The results indicate that the oil film bearing supported rotor system may successfully be coupled by the flexible coupling.

Dynamic analysis of a double-helical geared rotor system with oil-film bearing

2020 ◽  
Vol 92 (4) ◽  
pp. 653-662
Author(s):  
Ying-Chung Chen ◽  
Tsung-Hsien Yang ◽  
Siu-Tong Choi
Keyword(s):  
Dynamic Analysis ◽  
Rotor System ◽  
Content Type ◽  
Oil Film ◽  
Lateral Response ◽  
Helical Angle ◽  
Rotor Bearing ◽  
Bearing Stiffness ◽  
Bearing Force ◽  
Bearing System

Purpose This paper aims to study a dynamic analysis of a double-helical geared rotor system with oil-film bearing. Design/methodology/approach A finite element model of a double-helical geared rotor system with oil-film bearing is developed, in which a rigid mass is used to represent the gear and the Timoshenko beam finite element represents the shaft; the equations of motion are obtained by applying Lagrange’s equation. Natural frequencies, Campbell diagram, lateral responses, axial responses, bearing stiffness coefficients, bearing damping coefficients and bearing force are investigated. Findings Natural frequencies and Campbell diagram of a double-helical geared rotor system with oil-film bearing are investigated. An increased helical angle enhanced the axial response of the system and reduced its lateral response. The distance between the node and bearing affected the lateral response magnitude on the node. The farther away the gear pair was from the central part of the shaft, the higher the system’s resonance frequency became. The different gear pair position has a significant influence on the bearing stiffness coefficient and bearing force, but it just has a little effect on the bearing damping coefficient. Practical implications The model of a double-helical geared rotor system with oil-film bearing is established in this paper. The dynamic characteristics of a double-helical geared rotor system with oil-film bearing are investigated. The numerical results of this study can be used as a reference for subsequent personnel research. Originality/value Although the dynamics characteristics of geared rotor bearing system have been reported in some literature, the dynamic analysis of a double-helical geared rotor-bearing system is still rarely investigated. This paper showed some novel results that lateral and axial response results are obtained by the different helical angle and different gear positions. In the future, it makes valuable contributions for further development of dynamic analysis of a double-helical geared rotor-bearing system.

Dynamic Behavior Analysis of Three-Span Rotor-Bearing System with Rub-Impact Fault

2012 ◽  
Vol 460 ◽  
pp. 160-164 ◽  
Author(s):  
Song He Zhang ◽  
Yue Gang Luo ◽  
Bin Wu ◽  
Bang Chun Wen
Keyword(s):  
Nonlinear Dynamics ◽  
Behavior Analysis ◽  
Dynamic Model ◽  
Dynamic Behavior ◽  
Rotor System ◽  
System Response ◽  
Rotor Bearing ◽  
Set Up ◽  
Bearing System ◽  
Main Influence

The dynamic model of the three-span rotor-bearing system with rub-impact fault was set up. The influence to nonlinear dynamics behaviors of the rotor-bearing system that induced by rub-impact of one disc, two discs and three discs were numerically studied. The main influence of the rotor system response by the rub-impact faults are in the supercritical rotate speed. There are mutations of amplitudes in the responses of second and third spans in supercritical rotate speed when rub-impact with one disc, and there are chaotic windows in the response of first span, and jumping changes in second and third spans when rub-impact with two or three discs.

scholarly journals Research on Periodic Motion Stability of Rotor-Bearing System with Dual-Unbalances

2011 ◽  
Vol 2-3 ◽  
pp. 728-732
Author(s):  
Chao Feng Li ◽  
Guang Chao Liu ◽  
Qin Liang Li ◽  
Bang Chun Wen
Keyword(s):  
Stability Analysis ◽  
Phase Difference ◽  
Periodic Motion ◽  
Initial Phase ◽  
Shooting Method ◽  
Small Eccentricity ◽  
Rotor Bearing ◽  
Large Eccentricity ◽  
The Stability ◽  
Bearing System

Multiple freedom degrees model of rotor-bearing system taking many factors into account is established, the Newmark-β and shooting method are combined during the stability analysis of periodic motion in such system. The paper focused on the influence law of two eccentric phase difference on the instability speed of rotor-bearing system. The results have shown that the instability speed rises constantly with the eccentric phase difference angle increasing in small eccentricity system. When the two unbalance be in opposite direction, the system reached its maximum instability speed. However, the unstable bifurcation generates mutation phenomenon for large eccentricity system with the eccentric phase difference angle increasing. In summary, the larger initial phase angle can inhibit system instability partly. The conclusions have provided a theoretical reference for vibration control and stability design of the more complex rotor-bearing system.

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