INFLUENCE OF RANDOM VARYING LOAD ON VIBRATION SIGNAL GENERATED BY PLANETARY GEARBOXES DRIVING BUCKET WHEEL IN EXCAVATORS

摘要

Analysed planetary gearboxes are included into a driving system of bucket wheel excavators. The whole system may consist of a planetary gearbox as a first stage and a three stage parallel shaft gearbox. The basic problem of vibration condition monitoring is influence of an operation factor as random varying external load (RVOL). RVOL causes amplitude and frequency modulation (AFM). The first step for developing a sound method for condition monitoring is RVOL identification and investigation on its influence on the vibration signal. For the identification the properties of the whole driving system should be considered as is postulated by the authors in some published papers. All factors having influence on the vibration signal should be considered. One may expect after study of the mentioned factors that for the frequency modulation, besides RVOL, an electric motor characteristic has influence. So the operation factor - RVOL and design factor - and the property of the electric motor given by its characteristic have influence on the vibration signal. The paper shows the influence of design and operation factors that cause AFM. The RVOL is identified by filtration and demodulation processes.