Design and Construction Method of Forage Chopper for a Medium Sized Livestock Unit

Forage chopping machine is applied for preparation and cutting forage in villages and small sized livestock units. The machine is placed on a flat and balanced site and chops hay and silage in various lengths depending on the type of livestock. This study was performed in order to obviate the needs of small and medium livestock units to a suitable chopper. By surveying on several models of choppers and using the results of previous studies, the proper design was selected. All of the parts and transmission system of the chopper were designed and modeled by CATIA software. Considering the plant material cutting processes, the mechanism of guillotine quick return for cutting system was selected. The required power of the machine was calculated to be 5.5hp based on mechanical-physical properties of alfalfa stems. The advantages of this machine over the other available choppers in the market are: simplified structure, using fewer parts, producing low dust and above the all, it has a separate feeding unit which increases safety. A 1450 rpm electro-gearbox with the reduction ratio of 1:20 was used in this machine. The type of power transformation system from electro-gearbox to cutting unit was quick return mechanism self-return scotch-yoke mechanism. Theoretical capacity of the designed chopper machine was estimated as 1.8 ton/hr.