Stationary transducer response to planetary-gear vibration excitation with non-uniform planet loading

• Published in: Mechanical systems and signal processing Vol. 23; no. 4; pp. 1366 - 1381
• Main Authors: Mark, W.D., Hines, J.A.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.05.2009; Elsevier
• Subjects: Applied sciences; Diagnostics; Drives; Epicyclic gears; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Gear-health monitoring; Gears; Measurement and testing methods; Measurements common to several branches of physics and astronomy; Mechanical engineering. Machine design; Metrology, measurements and laboratory procedures; Physics; Planetary gears; Solid mechanics; Structural and continuum mechanics; Transmission error; Velocity, acceleration and rotation; Vibration, mechanical wave, dynamic stability (aeroelasticity, vibration control...); Gear-health monitoring; Diagnostics; Planetary gears; Epicyclic gears; Transmission error; Measurement; Helicopter; Cracked plate; Vibration; Variability; Fourier series; Modeling; Stationary condition; Ring; Accelerometer; Defect; Epicyclic gear; Monitoring; Variation coefficient; Gear tooth
• ISSN: 0888-3270; 1096-1216
• DOI: 10.1016/j.ymssp.2008.09.010

A relatively simple first-principles mathematical model of a generic planetary gear system is developed. System imperfections included are planet-to-planet variability in planet/ring-gear loading and generic ring-gear imperfections. General formulas for Fourier-series spectrum contributions of fixed-transducer responses to transmission-error vibratory excitations caused by planet/ring-gear tooth-meshing harmonics and ring-gear imperfections are derived, which include predicted effects caused by planet-to-planet variability in planet/ring-gear loading. Good approximations to the coefficient of variation of planet loading (CVPL) are shown to be readily obtainable from measured planet-carrier rotational-harmonic spectra obtained by fixed transducers. The predicted spectrum behavior is compared with fixed-accelerometer response spectra measured from UH-60A planetary systems without and with planet-loading variability caused by a cracked planet-carrier plate. The main features of predicted and measured spectra are in good agreement.