Research On Vibration Spectral Models Of Gear Fault Of Planetary Gearboxes With Floating Ring Gear

Planetary gearbox is widely used in aviation machinery, engineering machinery, power generation equipment and ship mechanical transmission system because of its unique advantages. But planetary gearbox generally works under heavy load and poor working environment situation, thus is very prone to failure. Once a fault occurs in the gear box parts, it may lead to the whole transmission system running abnormally, causing economic losses and casualties. Therefore, the research on fault diagnosis of planetary gear box and finding fault before big loss is very important. The monitoring device of the vibration detection method is simple, and is a very effective method to realize the identification of many kinds of early faults. So, it is also the focus of many researches.In-depth research on the spectrum structure of the vibration signals of gearbox and the spectrum characteristics of the gearbox under different faults can realize fault diagnosis of gearbox. But so far, there is no relevant research on the frequency spectrum structure of the planetary gearbox with floating gear ring, which is in line with the actual production and application.Based on the research of domestic and foreign scholars, this paper studies the vibration frequency spectrum characteristics of the planetary gearbox with floating ring gear. Aiming at the characteristics of the transmission structure of planetary gearbox with floating ring gear by comparison with transmission structure of planetary gearbox with fixed ring gear, effect of vibration signal transmission path on vibration spectrum structure of gearbox was studied, providing guidance to further reached the fault vibration signal amplitude modulation function of planetary gearbox with floating ring gear.On the basis of fixed axis gearbox vibration signal research results, planetary gearbox with floating ring gear fault vibration signal amplitude modulation function and frequency modulation function was established, proposing vibration signal time domain model of planetary gearbox with floating ring gear, and the frequency domain model of vibration signal was obtained by Fourier transform; to simplify the gearbox fault diagnosis, the envelope spectrum analysis method was used to study the gearbox fault vibration signal amplitude modulation and the envelope spectrum of the vibration signal model was obtained by Fourier transform of amplitude modulation function.Gearbox fault diagnosis test bench was built, and by referring to the transmission structure of SD 16 gearbox which is widely used in bulldozer in the field of engineering machinery, improving the compound planetary gear train and taking into account the constraints of its operation and lubrication and other conditions, the planetary gearbox with floating gear ring was designed which is in line with the actual production and application.Finally, the bench test is conducted by the use of the gearbox fault diagnosis test bench and planetary gearbox with floating ring gear. The vibration signal time domain model and frequency domain model of planetary gearbox with floating ring gear and research on amplitude modulation of fault vibration signal of gearbox based on envelope spectrum analysis method was verified.After experimental verification, the vibration spectral model and amplitude demodulation analysis method for fault diagnosis of planetary gearbox with floating gear ring provides a simple and reliable technique for fault diagnosis of planetary gearbox with floating gear ring.