Testing the reliability of the threshing unit is difficult and thus often neglected before the harvesting season, which can result in breakdown maintenance during peak harvesting time in difficult-to-access areas for sensor mounting. In this paper, the vibration analysis of the threshing condition of the combine harvester was performed by introducing the bracket for inaccessible locations. The Adash A4900 Vibrio M analyzer (Adash spol. s.r.o., Ostrava, Czech Republic) was used for a vibration signal measurement and the DDS Adash software was used for signal processing. The demodulated fast Fourier transform (FFT) root mean square (RMS) (500 Hz–16 kHz) method was used to evaluate the bearing condition and DDS Adash Fault Source Identification Tool (FASIT) technology was used to evaluate other mechanical conditions such as the looseness, misalignment, and unbalance of the threshing unit of the Massey Ferguson series of combine harvesters. Modal and random vibration analyses were performed on the bracket and components and compared to prevent the resonance phenomenon using the Ansys Software (Ansys, Inc., Canonsburg, PA, USA). The constrained modal analysis of the threshing drum was performed to observe the deformation. Decent results were obtained from the method used. The method was again validated by the tangential threshing test bench and successfully determined the bearing fault condition. The method used is an uncomplicated and effective way of performing the bearing analysis of the tangential unit of the combine harvester.

The threshing mechanism is the main component of the combine harvester on which the grain separation and cleaning qualitative work indicators depend. It is important to ensure that all threshing mechanism components, including the threshing drum bearings and all other bearings of the combine, are working properly and reliably. There are many places in the combine where it is not possible to measure bearing vibrations directly without dismounting them, since there is no suitable spot to mount a sensor. The paper investigates the threshing drum rolling bearing condition of combines, which are difficult to access, by using a vibration diagnostics technique utilizing a newly manufactured steel bracket. The vibration measurements and analysis were conducted by the Adash A4900 Vibrio M analyzer (Adash spol. s.r.o., Ostrava, Czech Republic). The vibration source measurement was based on the fast Fourier transform (FFT) spectrum analysis. Analysis of the experimental results showed that average squared velocity values (in the frequency interval of 10–1000 Hz), together with other measured vibration parameters, can be used for the combine threshing drum‘s bearing condition evaluation.

Agricultural tractors possess front loaders that are employed for the handling and transportation of materials, but are exposed to mechanical vibrations and shocks from ground undulations and sudden variations in the load. These vibrations are harmful to the durability of the parts, the comfort of the driver, and the longevity of the machine. In this current study, the performance of the hydraulic accumulator to mitigate such vibrations for a Foton 904 wheeled tractor equipped with a TZ10C-824 front loader is studied. Vibration measurements were taken by an experimental Brüel & Kjær 3050-A040 analyzer under various loading configurations (no loading, 180 kg, and 312 kg), with or without a 1.4 L, 50-bar nitrogen gas-charged Fox Opera Mi Italy hydraulic accumulator. Results reveal that maximum accelerations were as much as 6.24 m·s⁻² without an accumulator during testing of a 312 kg load, whereas they were extremely low at 2.66 m·s⁻² when the accumulator was activated. Frequency-domain analysis verified that the main vibrations were within the range of 3–4 Hz, with FFT peak amplitudes dropping from 5.6 m·s⁻² to 2.4 m·s⁻² upon the accumulator’s operation. The observations verify the effectiveness of the accumulator in vibration intensity reduction, absence of high-frequency shock loads, and ride comfort, along with structural safety improvement. The study provides a solid platform for further enhancement in vibration control techniques for agricultural machines and loader system design.