الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 139 |  |  |
| | | from | 139 | | |
Abstract
The main aims of the present study is to solve the problems which face the mechanical threshing of sunflower crop by designing a prototype suitable for small farmers . It was manufactured in a local workshop with simple materials and operates on the principle of traditional movement of material . it consisted of a threshing unit, power drive unit and power transmission unit. The threshing unit separates seeds from sunflower heads and consists of a small drum rotating against concave . for proceeding all treatments, and replicates an electric motor provided with over load protection to overcome higher and sudden loads . At the end of drum shaft there is three changeable pulleys connected to V belt Theses pulleys and belt formed the power transmission unit and used to transmit power from the power drive unit to the threshing unit . the units were mounted on a frame made of steel . The design bases for the local thresher are as follows: Using three cylinder speeds 8.3,10.9,and 14.7 m/s three concave clearance 2,3,4 cm three spikes numbers 8,12,and 24 in 2,3 and 6 rows each one contents 4 teeth three levels of moisture content 19,14 and 10 % . the machine performance was evaluated according to threshing efficiency , seed quality and threshing capacity . the optimum combination of drum speed, concave clearance, spikes numbers and position, and moisture content of the sunflower thresher in order to obtain the minimum damage , best threshing efficiency and best threshing capacity .at (14.7 m/s) drum speed, moisture content (10%) , spikes number and position (24 teeth X 6 rows) and concave clearance (4 cm ) .achieved the highest threshing efficiency (95.1%) , threshing capacity (12.25 kg/min) and the lowest brooking ratio(2.49 % ).the developed sunflower thresher if operated at these combinations of parameters will give optimum performance.