2D Analytical Model for Evaluation of the Forces in the Three Point Hitch Mechanism

Abstract Large investments, research efforts and time have been allocated till  nowadays for innovation of agricultural tractors and machinery, with  the primary aim to increase their productivity, reliability, durability,  as well as the environmentally friendly, safe and easy usage.  Following this general trend, present work is focused on theoretical  analysis of the forces acting on the links of the three-point hitch  mechanism. The simulation algorithm and computer code have been developed for calculation of draft forces by two methods (following ASAE D497.4 standard and Goryachkin approach), depending on the  three point linkage geometry and mouldboard technical  characteristics, and calculation of forces acting on lower and upper  links of three-point hitch mechanism. Calculated forces values, based  on ASAE draft, exposes smaller differences compared to  experimental values, while for the Goryachkin method improvement  is possible by entering experimental values for soil resistance  coefficient k and coefficient of dynamic resistance e, as we did in this  study performing measurements on the aggregate comprehending  tractor IMT 539 (IMT Belgrade, Serbia) and two furrow  moldboard  plough PTO 2.25 (OLT, Osijek, Croatia).