4. Desitn of the threshing device
1) hand feed type power thresher.
The threshing device is mainly composed of the threshing cylinder with teeth, the concave
(1) The threshing cylininder is made of a steel plate and its diameter is generally 360 to 420 mm. width of cylinder ranges from 450 to 600 mm.
(2)The most suitable condition of the peripheral speed is 13 to 15 m/s.
The peripheral speed v of the threshing teeth is calculated by the fallowing equation :
(2) Tooth on the cylinder.
The tooth of the self-feeding thresher are made of 4-5 mm. steel wire or steel plate and height of tooth is 50-76 but almost of them are designed with 60 mm of height. Kinds of tooth are 2 type as u-type and v-type. And angle of tooth is about 20-30 degrees.
The arrangement of threshing teeth of hand-feed power thresher on the maket are shown in Fig. 10.