A torque calculator for rotary tiller using the laws of classical mechanics

The theoretical understanding of the working mechanism of a machine, prepares an opportunity to re-design it without performing the re-fabrication process. In this study, a thorough mechanical model for a rotary tiller is developed that contains both kinematics and kinetics viewpoints of its operation. Specifically, the main aim of this model is to develop a theoretical calculator concerning the torque and power requirement of this active tillage machine. To perform the required calculations simply, and automatically, the derived equations were entered into an Excel spreadsheet, and the results was presented as the torque and power of a rotary tiller. The developed formulas were verified by comparing the results of the model with the acquired results of other studies. The average errors of the calculated specific work of a rotary tiller compared with the results obtained in the studies of Asl and Singh (2009) and Bernacki et al., (1972) were 16% and 14%, respectively. The average error of the calculated power by comparison with the results of Perdok and Burema (1977) was 21%. The average error of the calculated fetch ratio in comparison with the results of the study of Thakur and Godwin (1989) was 9%. Finally, the average error of the calculated torque in comparison to the study of Chertkiattipol and Niyamapa (2010), was 5%. Therefore, good estimates are expected to be obtained when using the developed calculator.