The mechanics of tractor performance and their impact on historical and future device designs

Abstract

This thesis utilizes a terramechanics-based farm tractor model to predict machine performance. This model is used to reflect on tractor evolution throughout the last century and the physics-based principles that govern tractor performance. Insights from this model and reflection can help designers create new farm tractor embodiments, especially for markets where farming practices and industrial context differ significantly from those that shaped the conventional tractor's major evolutionary steps. It is shown how the small tractor evolved to its conventional modern form in in the early 1900s in USA pushed not only by suitability to domestic agriculture at the time but also efficiency in contemporary mass manufacturing and symbiosis with the burgeoning automotive industry. The farm tractor model as suggested in this thesis is proven to be in good agreement with published experimental data and historical standarized tractor testing. Inline drive wheels and mounting soil working implements between front and rear axles are identified as high potential design options for adapting the small tractor to modern emerging markets where draft animals are the dominant source of draft power.