This paper is experimental results on flowing velocity of paddy and screening character of paddy and rice by the screen, oscillating in the reciprocating, elliptical and circular motion. The four-bar linkage was adopted in order to oscillate the screen in that motion respectively.
The main results were as follws :
1) Oscillating screens used to the agricultural machinery have, in general, large amplitude and small frequency as in Fig (1).
2) The flowing velocities of paddy varied by the frequency, amplitude and angle of projection in the reciprocating motion, by the frequency, angle of projection, rate of amplitude (minor to major axis) and direction of rotation in the elliptical motion, and by the frequency, amplitude and direction of rotation in the circular motion, respectively.
3) On the screening of rice from the paddy, there were the optimum frequencies according to the feeding rate of each oscillating types of screen, and the screening rates of them decreased with the increase of feeding rate.
4) The maximum values of screening efficiency were 60-70%, though frequencies of that value were varied according to the oscillating types of screen. Also the screening efficiencies dcreased with the increase of the feeding rate.
5) The undersize recoveries were similar to the characteristics of screening rate of rice, and yet they increased with the increase of the length of screen. The coefficients of diffusion were decreased with the increase of the length of screen.