Analysis of Threshing Mechanism of Head Feeding Thresher (Part 1)

This study presents analysis of threshing mechanism in Japanese type head feeding combine. For this purpose, rice movement was analyzed in order to consider the location of threshing tooth and grain at impact, the relation between impulse and detachment, and the probability of such a phenomenon. This report describes the rice movement on threshing cylinder. Flexural rigidity and mass of rice were measured and its vibration characteristic was analyzed. The natural frequency of rice was low compared with the speed of the threshing tooth, and rachis and rachis-branch moved along with the movement of the tooth. Hence, rice movement on threshing cylinder was analyzed by considering geometric condition between the tooth and rice. The head of rice moved perpendicular to the axis of threshing cylinder because of friction force between the tooth and rice. (Keyword) threshing, head feeding thresher, rice movement, threshing tooth, flexural rigidity, vibration analysis