Evaluation of bearing reliability of combine harvester straw chopper

Abstract

In most common cases, combine harvester failure occurs during harvesting the fields. In order to avoid faults, it is necessary to prepare the combine harvester for work in advance. There are many rotating parts in this machine, which work depends on each other. In the case of a unit failure, the machine cannot be operated further. To avoid these problems, it is necessary to find faults and remove them as early as possible. In order to minimize the time for determination of the combine harvester bearing condition, the vibro analytical methods are used to determine the status of the bearings without dismounting the units. This paper provides the research results of the rolling bearing condition of the combine straw chopper using vibration diagnostics. Identification of the vibration sources is based on the Fast Fourier Transform (FFT) spectrum analysis. From the obtained results and data analysis, it can be stated that the average values of vibration velocity (in frequency interval 10- 1000 Hz) in combination to other measured parameters can be used to assess the combine straw chopper bearing condition. The obvious defects should occur when the amplitude of the vibrations increases, the bearing balls passing through the outer bearing ring, which theoretical frequency equals fRPI = 36 Hz, the inner ring fRPV = 44 Hz and the ball defect fRDD = 66.7 Hz. From practical point of view, the use of the vibro analysis technique together with the temperature analysis technique would significantly increase the accuracy for determination of the bearing defect.