Sensitivity Analysis of Tractor Three-point Hitch Linkage System

Abstract

Abstract

Farm tractors have the three-point hitch linkage system for the attachment of farm implements.  The three-point hitch linkage system of the Indian tractors have the provision to attach the lift rod at two or three points on the lower link and attach the upper link at two or three locations on the tractor body. Appropriate utilization of these provisions during farm operations using various implements ensures that the engine power is efficiently utilized, proper weight transfer from the implement to rear axle of the tractor takes place and sufficient stability of tractor against overturning is maintained during operation. The sensitivity analysis of the hitch linkage system of a popular model of an Indian tractor was conducted through kinematic linkage analysis. The study revealed that heavy operations or operations using heavy implements or operations under position control mode must be performed by connecting the lift rod to the lower link far away from the pivot point of lower link and attaching top link to the pivot point located farther away and higher above the rear axle centre. This also ensures minimum longitudinal tilt of implements during operation. Heavy implements under draft control mode and implements used for lighter and finer operations must be operated by connecting the lift rod to the lower link near the pivot point of lower link and attaching top link to the pivot point located nearer to the rear axle centre. The outcome of the sensitivity analysis is general and applies to most of the Indian tractors.

Keywords: Mechanical advantage, Sensitivity analysis, Three-point hitch, Vertical convergence distance, Virtual hitch point