Military Potential Test of the 'Door Hinge' High-Speed Rotor System

1964 ◽  
Author(s):  
ARMY AVIATION BOARD FORT RUCKER AL
Keyword(s):  
High Speed ◽  
Rotor System ◽  
Door Hinge ◽  
Potential Test

Transient Vibration of High-Speed, Lightweight Rotors Due to Sudden Imbalance

1983 ◽  
Vol 105 (3) ◽  
pp. 480-486 ◽  
Author(s):  
M. Sakata ◽  
T. Aiba ◽  
H. Ohnabe
Keyword(s):  
Transient Response ◽  
High Speed ◽  
Rotor System ◽  
Response Analysis ◽  
Transient Vibration ◽  
Flexible Shaft ◽  
Shaft System ◽  
Transient Response Analysis ◽  
Flexible Disk ◽  
Blade Loss

In the field of rotor dynamics, increased attention is being given to the transient response analysis of the rotor, since the effects of impact loading and vibrations of the rotor arising from blade loss can be studied by a time transient solution of the rotor system. As recent trends in rotating machinery have been directed towards lightweight, high-speed flexible rotors, the effect of flexibility on transient response analysis is becoming of increasing importance. In the present paper, a transient vibration analysis is carried out on a flexible-disk/flexible-shaft system or rigid-disk flexible-shaft system subjected to a sudden imbalance that is assumed to represent the effect of blade loss. To solve the basic equation governing a rotating flexible disk the Galerkin’s method is used, and the equation of motion of the rotor system is numerically solved by employing the Runge-Kutta-Gill’s method. Experiments were conducted on a model rotor having a blade loss simulator; the shaft vibrations were also measured. The validity of the anaytical results was demonstrated by comparison with the experimental results.

Internal Rotor Friction Induced Instability in High-Speed Rotating Machinery

1993 ◽  
Author(s):  
James F. Walton ◽  
Michael R. Martin
Keyword(s):  
Internal Friction ◽  
Natural Frequency ◽  
High Speed ◽  
Critical Speed ◽  
Rotating Machinery ◽  
Rotor System ◽  
Analytical Models ◽  
Interference Fit ◽  
Internal Rotor

Abstract Results of a program to investigate internal rotor friction destabilizing effects are presented. Internal-friction-producing joints were shown to excite the rotor system first natural frequency, when operating either below or above the first critical speed. The analytical models used to predict the subsynchronous instability were also confirmed. The axial spline joint demonstrated the most severe subsynchronous instability. The interference fit joint also caused subsynchronous vibrations at the first natural frequency but these were bounded and generally smaller than the synchronous vibrations. Comparison of data from the two test joints showed that supersynchronous vibration amplitudes at the first natural frequency were generally larger for the interference fit joint than for the axial spline joint. The effects of changes in imbalance levels and side loads were not distinguishable during testing because amplitude-limiting bumpers were required to restrict orbits.

scholarly journals Rotor dynamic experimental investigation of an ultra-high-speed permanent magnet synchronous motor supported on a three-pad bidirectional gas foil bearing

2019 ◽  
Vol 11 (9) ◽  
pp. 168781401987536
Author(s):  
Wenjie Cheng ◽  
Zhikai Deng ◽  
Ling Xiao ◽  
Bin Zhong ◽  
Wenbo Duan
Keyword(s):  
Permanent Magnet ◽  
High Speed ◽  
Permanent Magnet Synchronous Motor ◽  
Synchronous Motor ◽  
Rotor System ◽  
Permanent Magnet Motors ◽  
Foil Bearings ◽  
Foil Bearing ◽  
Ultra High Speed ◽  
Rotor Dynamic

With a 10-kW, 120,000-r/min, ultra-high-speed permanent magnet synchronous motor taken as a prototype, experimental research is conducted on the rotor dynamic behaviours of a three-pad bidirectional gas foil bearing high-speed motor rotor system. Load-carrying properties of the three-pad bidirectional gas foil bearing are analysed, and natural frequencies of conical and parallel whirling modes of the elastically supported rotor are calculated based on an appropriate simplification to the stiffness and damping coefficients of the gas foil bearings. The prototype passes through a 90,000-r/min coast-down experiment. Experiments show that there are violent subsynchronous whirling motions that are evoked by the gas foil bearing–rotor system itself. The cause of shaft orbit drift is analysed, and the corresponding solution is put forward. The theoretical analysis and experimental results can offer a useful reference to the bearing–rotor system design of ultra-high-speed permanent magnet motors and its subsequent dynamic analysis.

scholarly journals Dynamic Characteristics of Gear Coupling and Rotor System in Transmission Process Considering Misalignment and Tooth Contact Analysis

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1336
Author(s):  
Wei Fan ◽  
Hong Lu ◽  
Yongquan Zhang ◽  
Xiangang Su
Keyword(s):  
Finite Element ◽  
Dynamic Model ◽  
Calculation Method ◽  
High Speed ◽  
Low Frequency ◽  
Rotor System ◽  
Integral Approach ◽  
Time Frequency ◽  
Low Frequency Vibration ◽  
Mass Eccentricity

The dynamic vibration of the gear coupling-rotor system (GCRS) caused by misalignment is an important factor of low frequency vibration and noise radiation of the naval marine. The axial misalignment of gear coupling is inevitable owing to mass eccentricity, and is unconstrained in axial direction at high-speed operation. Therefore, the dynamic model of GCRS is proposed, considering gear-coupling misalignment and contact force in this paper. The whole motion differential equation of GCRS is established based on the finite element method. Moreover, the numerical calculation method of meshing force, considering the uniform distribution load on contact surface, is presented, and the mathematical predictive time–frequency characteristics are analyzed by the Newmark stepwise integral approach. Finally, a reduced-scale application of the propulsion shaft system is utilized to validate the effectiveness of the proposed dynamic model. For the sensibility to low-frequency vibration, the natural frequencies and vibration modes of GCRS are analyzed through the processing and analysis of acceleration signal. The experimental dynamic response and main components of vibration are respectively consistent with mathematical results, which demonstrate the effectiveness of the proposed dynamic model of GCRS with misalignment. Furthermore, it also shows that the proposed finite element analysis and calculation method are suitable for complex shafting, providing a novel thought for dynamic analysis of the propeller–shaft–hull coupled system of marine.

Analysis of Stiffness of Viscoelastic-Friction Damper for High-Speed Rotor System

2012 ◽  
Vol 538-541 ◽  
pp. 768-772
Author(s):  
Wen Zhong Li ◽  
Fu Xiang Zhang
Keyword(s):  
Friction Coefficient ◽  
High Speed ◽  
Critical Speed ◽  
Cone Angle ◽  
Rotor System ◽  
Outer Ring ◽  
Axial Stiffness ◽  
Friction Damper ◽  
Damping Material

To reduce the excessive vibration of a high-speed rotor system as it passes its critical speed, a viscoelastic-friction damper(VEFD) are introduced into the support. Its stiffness factor is analyzed. Results show, the stiffness factor decreases with the cone angle increasing among 55-80 degrees monotonically. And it is the same trend when the stiffness of the damping material ring decreases. In the case of friction coefficient among 0.1-0.5, the stiffness factor increases monotonically. So adopted a proper structure, suitably chosen the above parameters and the axial stiffness of the outer-ring, the damper can present appropriate stiffness.

Dynamic Response of the Vertical Rotor System to Base Excitation

2008 ◽  
Author(s):  
Jianli Zuo ◽  
Jianjun Wu ◽  
Ping Li ◽  
Shenjian Su
Keyword(s):  
Dynamic Response ◽  
Physical Model ◽  
High Speed ◽  
Lagrange Equation ◽  
Rotor System ◽  
Operating Speed ◽  
Base Excitation ◽  
Rotating Machine ◽  
Vertical Rotor ◽  
Rotary Speed

The physical model of a high-speed vertical rotating machine was taken as the example. The motion differential equations of the rotor system were established by the Lagrange equation and numerically solved by the Wilson-θ method. The whirling characteristics of the rotor excited by the base’s harmonic motions have been analyzed. The whirling directions are different between the rotor’s upper and lower ends. And the whirling characteristics of the rotor vary with the frequency of the base’s motion. Besides, there exists such a region of the rotor’s rotary speed, in which the whirling characteristics and amplitudes of the rotor system are relatively steady, so the aseismic tests at a certain lower speed can be done to examine the aseismic capability of the rotor system at operating speed.

Sign in / Sign up

Export Citation Format

Share Document