Modes of propulsion of Farm Machines

Farm machines or implements are divided into four main type or classes on the basis of their modes of derivation of power for their propulsion. With the exception of the self – propelled machines, the size and weight of implements or machines and type of prime mover to match influence their modes of attachment or types of tractor – implement combination in most cases. The four main types of implements are mounted implement, semi – mounted implement, self – propelled machine and trailed implement. These four types or classes of machines can be said and expatiated on as follows;

Mounted implement

This type of implement is attached to the tractor through the three – point linkage in such a way that it is completely supported by the tractor when in raised or in transport position. This three – point linkage attachment has advantage over the trailed implement or machine such as initial reduction in cost, easier transportation, simpler and more accurate control, reduce headland compaction and improve traction by transforming the weight of the machine or implement to the tractor.

Semi – mounted implement

In a semi – mounted implement, the front is supported partially on the tractor linkage or drawbar through a horizontal or nearly horizontal hinge axis, while the implement rear is supported or guided by its own wheel or the wheels. For long or heavy implement, this arrangement is necessary or advantageous as it averts the excessive load that would otherwise be imposed on the tractor hydraulic system and the tractor`s instability due to the excessive overhang acting on it.

Self – propelled machines

Self – propelled machines are the type of machine such as one which has the propelling power unit as an integral part of the machine. Most combine harvesters are self – propelled machine. Very recently, self – propelled boom sprayers are featuring in modern mechanized agriculture.

Trailed implement

This implement is pulled and guided from one hitch point and is never completely supported by the tractor. A trailed implement is supported by two or three wheels and trails behind the tractor when hitched to the drawbar.