Feed Planet Magazine Issue-Sayı: 09 November-December/Kasım-Aralık 2017

57 COVER STORY • KAPAK DOSYASI FEED PLANET MAGAZINE November-December • Kasım-Aralık 2017 At the 4th Stage, the bearing failure frequencies do not oc- cur and it is replaced with general vibration distributed to the ground. 1XRPM will be seen as active again as it goes towards the end. The high-frequency noise amplitude is reduced but the gE values are still at high levels. At the 3rd Stage, bearing failure frequencies and harmonics are ob- served. Many harmonics will be observed along with the sidebands due to abrasion and HFD will continue to increase from 0.5 to 1.0 gE. At the 2nd Stage, failure initialization is observed near the bearing failure frequencies and these frequencies occur at a range of 30k-120k CPM. At the end of the 2nd stage, side- band frequencies begin to appear below or above the natural frequency (HFD example 0.25-0.50gE). At the 1st Stage, the bearing will become unusable.