Open Access. Powered by Scholars. Published by Universities.®

Mechanical Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

External Link

2012

Jeffcott rotor

Articles 1 - 2 of 2

Full-Text Articles in Mechanical Engineering

Stability Analysis Of Vertical Rotor With External Stiffness And Damping Supported On Journal Bearings, Jerzy Sawicki, T. Rao Nov 2012

Stability Analysis Of Vertical Rotor With External Stiffness And Damping Supported On Journal Bearings, Jerzy Sawicki, T. Rao

Jerzy T. Sawicki

This paper presents the stability boundaries for vertical Jeffcott rotor, extended vertical Jeffcott rotor, and an external flexible damped support vertical Jeffcott rotor with external stiffness and damping supported on hydrodynamic journal bearings. This paper extends the analysis presented by Guo and Kirk [1,2] by considering the effect of external stiffness on the rotor bearing system stability. The minimum value of negative real parts of all eigenvalues used to describe stability characteristics is determined from the numerical solution of characteristic equation of rotor bearing system. It is shown that for a vertical Jeffcott rotor with external stiffness and damping there …


Vibration Based Method For Shaft Crack Detection, Zdzisław Gosiewski, Jerzy Sawicki Nov 2012

Vibration Based Method For Shaft Crack Detection, Zdzisław Gosiewski, Jerzy Sawicki

Jerzy T. Sawicki

Various excitation techniques have been developed to extract information on dynamic state of rotating machinery. This paper will address the effectiveness of selected excitations and analysed signals towards health monitoring of rotating machines from the cracked shaft dynamics point of view. The computer simulation study is based on the uncracked and cracked Jeffcott rotor models and the efficiency of the selected approaches is examined. As the excitation we have considered the rotor unbalance, additional harmonic forces, and input conditions. The combined resonances as diagnostic indicators of the crack in the shaft can be clearly seen in the total frequency spectrum …