Dynamic Characteristics of the Coupled System of the High Pressure Rotor and the Radial Driveshaft of a Turbofan Engine

Abstract

In a turbofan engine, the high pressure rotor and the radial driveshaft, which transmit the power from the internal gear-box to the external gear-box, are geared by a spiral bevel gear pair. In this paper, a reasonably simplified dynamic model of the coupled rotors system is established, and then, the coupled stiffness matrix and coupled damping matrix of the spiral bevel gear pair are deduced. A shaft element method is proposed to investigate the lateral-torsional coupled vibration equations of the gear-rotor system. Furthermore, the mode shapes and unbalance responses of this two rotors coupled system are simulated. The results indicate that the system derives many new modes and the exciting forces on a rotor of the system would be passed to the other rotor for the gears meshing. When the rotor dynamics of a turbofan engine is being analyzed, the high pressure rotor and the radial drive shaft must be viewed as a whole. The dynamic balance precision of the rotors should be qualified properly, in order to improve the dynamic quality of the turbofan engine.

Stability Margin Sensitivity Analysis of a Multi-Rotor System Geared by Spiral Bevel Gear Pairs

“…According to reference [2], the global equations of the geared multi-rotor system can be set up as follows. The multi-rotor system (as shown in fig.…”

“…The multi-rotor systems geared by spiral bevel gear pairs are widely used in ships, vehicles, aircrafts and machine tools [1,2]. The study on the dynamic characteristic and the stability of the multiple rotor system is focus in engineering field at all times [1][2][3][4][5][6].…”

“…The multi-rotor systems geared by spiral bevel gear pairs are widely used in ships, vehicles, aircrafts and machine tools [1,2]. The study on the dynamic characteristic and the stability of the multiple rotor system is focus in engineering field at all times [1][2][3][4][5][6]. To study the stability margin sensitivity to the parameters of the geared rotor system is prerequisite to carry on structure optimization design and vibration control.…”

Selected topics of design of the bevel gear prototypes for aviation industry

“…-weryfikacji rezultatów otrzymanych na modelach opracowanych w środowiskach CAD i MES (sumaryczny ślad współpracy, dokładność kinematyczna, wartości naprężeń), -ocenie wytrzymałości zmęczeniowej przekładni na różne postacie zużycia (pitting, scoring, złamanie u podstawy zęba), -określeniu częstości drgań własnych przekładni, częstości rezonansowych oraz ustaleniu zakresów prędkości, odpowiadających spokojnej pracy przekładni [1,2,7].…”