Виділення бічних смуг на спектрах потужності вібрації тягових редукторів електропоїздів

Abstract

UA: У статті застосовується метод синхронного усереднення вібрації в часі для виділення діагностичних ознак технічного стану тягового редуктора електропоїзда. Цей метод забезпечує усунення випадкових складових і залишає частотні компоненти, які є синхронними до частоти обертання шестірні та зубчастого колеса тягового редуктора. Розраховані спектри потужності вібрації після синхронного усереднення дозволяють за наявними посиленими бічними смугами визначати локалізовані й розповсюджені пошкодження шестірні або зубчастого колеса.

EN: The paper deals with the time-synchronous averaging technique of vibration signals for extraction of the features of the technical state of electric train traction gearboxes. Simulation of the vibration of the faultless gear mesh, and gearwheel with a cracked tooth and strong deterministic component was carried out. The rotation frequencies of gearwheel and pinion, and the mesh frequency are clear visible on the vibration power spectrum. Taking into account the poor visibility of the sidebands around mesh frequency on the power spectra, the time-synchronous averaging technique enhances the sidebands, the width of which corresponds to the gearwheel rotation frequency and influences weakening of the sidebands of the faultless pinion. During the experimental research the traction gearbox vibration of electric train was acquired on the test bench in a depot, and the calculated power spectrum has not identified sidebands and mesh frequency. After the time-synchronous average within 18 revolutions for the pinion and gearwheel frequency, the vibration power spectra were acquired. The time-synchronous average technique eliminates random and non-synchronous components while keeping the frequency components that are synchronous to the rotating frequency of the pinion and gearwheel of the traction gearbox. On the vibration power spectra in the vicinity of the mesh frequency the strong sidebands are visible, and they do not coincide with the previously calculated rotation frequencies, which means the absence of gearwheel faults. At the vibration power spectrum for the pinion there are six sidebands in the vicinity of the meshing frequency that coincide with the previously calculated pinion rotation frequencies, which means the presence of localized or distributed faults for the pinion. Disassembling of the traction gearbox shows a crack of the rolling bearing inner race and faultless state of the gear mesh. It was established that the sensitivity of the time-synchronous average technique makes it possible to identify not only localized faults extraction but also distributed faults such as eccentricity and misalignment of the pinion shaft through the modulation of the sidebands on vibration power spectra of the gearwheel.