Design and Testing of an Electric-Powered Walking Tractor

The walking tractor, driven by an internal combustion engine, plays an essential role in agricultural mechanization in Italy, both on small farms and in growing houses. But its utilization is associated with high levels of noise and vibration and in closed environments such as greenhouses or plastic film houses, with the presence of exhaust engine gases. The result is extremely severe working conditions for the operators. To reduce these problems two electrically driven walking tractors have been designed and built: the first, with a rated power of 3 kW is driven by alternating current (a.c.) with a power cord and the second, with a rated power of 2 kW is driven by a direct current (d.c.) by means of accumulator batteries. Soil preparation tests were made and showed little difference in the cultivation achieved compared with engine-driven machines. The machines have also been used on turkey farms for periodically breaking up the surface layer and mixing the litter. High labour productivity (500 m2/h per worker) and 30% sawdust saving for litter were obtained. The d.c. walking tractor has been tested in transport (1·5 h of battery life at 5·5 km/h) and mowing operations (work rate of 0·15-0·18 ha/h), using a coupled single-axle trailer and a mowing bar, respectively.