Automatic Ballast Position Control for Tractors

ABSTRACT A67-kW (90 hp), two-wheel-drive tractor was equipped with an automatic control system which sensed the vertical reaction on the front axle and moved 1 000 kg (2200 lb) of ballast in a fore-and-aft mode to maintain this reaction at a predetermined, safe but otherwise minimum, level. Adequate front axle reaction was maintained in all conditions except the potentially dangerous circumstances involving sudden lifting of heavy mounted implements or sudden applications of draft loads at high drawbar heights. Field tests indicated potential improvements of drawbar performance and fuel economy in the range of 2 to 20% when the dynamic load on the front axle was reduced from approximately 30% to approximately 13% of tractor weight.