Assessment of required torque and power by-big square baler during the wrapping and baling process

The big square baler is an operating machine that performs the harvesting of hay and crop residues (straw) and the wrapping and baling process of big prismatic bales. The main operating organs of the machine are: i) the harvesting head; ii) the feeder; iii) the compression chamber and iv) the binding apparatus. The required power by the HD1270 big square baler, manufactured by Cicoria in Palazzo San Gervasio (near Potenza, Italy) has been studied. This big baler HD1270 is equipped with specially designed and manufactured devices aimed at reducing the costs of wrapping and baling. Practically these devices are the “Leverage Piston System”, the “Top Feeding System” and the “Controlled Binding System”, which manage, respectively, the motion of the piston, the feeding of the product and the binding operations. According to the manufacturer's technical specifications, these devices allow minimum required power from the tractor down to only 60 kW. Using an ad hoc high precision torque meter and tachometer, mounted between the tractor power take-off (PTO) and the cardan shaft connecting the HD 1270 big baler, the required torque values and power during the straw wrapping and baling process were measured and recorded. The tests were repeated considering different operating conditions. The obtained results were statistically evaluated in the time domain and clearly showed that the effective required power complies with technical specifications. The variability in stress could induce fatigue phenomena in the components that make up the piston motion transmission chain, with a reduction in their useful life.