It is a multi-purpose walking machine mainly used for traction and transportation composed of engine, chassis, electrical and other systems.
The Garden Tractor can travel by the power of the internal combustion engine through the transmission system. The driving wheel that obtains the driving torque then gives the ground a small, backward horizontal force (tangent force) through the tire pattern and tire surface. This reaction force is to push the tractor forward Driving force for driving (also called propulsion force).
This 3D model designed by SolidWorks 2017, detailed design like pictures below, step files included for you. The file total of 100 MB.