Adaptive Electronic Tractor Shift Control System

The ability to shift gears on a moving farm tractor without using the clutch, makes the operator's job easier, and improves his productivity. This feature, often referred to as “powershift”, has been implemented electrically and hydromechanically by farm equipment manufacturers. The Case Corp 5100 Series Maxxum tractor offers an electronic powershift in which clutch pressure, timing and hydraulic fluid temperature are utilized for simple adaptive shift control. This paper describes the strategy incorporated into the Maxxum control system.