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

Abstract

Large investments, research efforts and time have been allocated tillnowadays for innovation of agricultural tractors and machinery, withthe 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 theoreticalanalysis of the forces acting on the links of the three-point hitchmechanism. The simulation algorithm and computer code have beendeveloped for calculation of draft forces by two methods (followingASAE D497.4 standard and Goryachkin approach), depending on thethree point linkage geometry and mouldboard technicalcharacteristics, and calculation of forces acting on lower and upperlinks of three-point hitch mechanism. Calculated forces values, basedon ASAE draft, exposes smaller differences compared toexperimental values, while for the Goryachkin method improvementis possible by entering experimental values for soil resistancecoefficient k and coefficient of dynamic resistance ε, as we did in thisstudy performing measurements on the aggregate comprehendingtractor IMT 539 (IMT Belgrade, Serbia) and two furrow moldboardplough PTO 2.25 (OLT, Osijek, Croatia).