PROBLEM TO BE SOLVED: To provide a threshing drum having a plurality of threshing teeth supporting rods connected to a supporting plate integrally rotatable with a rotation spindle, durable against the threshing reaction force without adding a special reinforcing member, and capable of being easily manufactured.SOLUTION: In the threshing drum, a first reinforcing rib 42 and a second reinforcing rib 43 are integrally molded with the supporting plate 39 in such a way that the first reinforcing rib 42 and the second reinforcing rib 43 are continuously juxtaposed in the radial direction of the rotation spindle 31. The first reinforcing rib 42 is formed in such a way that the shape of the cross section along the radial direction of the rotation spindle 31 swells forward in front of the rotation spindle, and that the shape as seen in the direction along a shaft center P of the rotation spindle 31 is circular around the shaft center P of the rotation spindle 31. The second reinforcing rib 43 is formed in such a way that the shape of the cross section along the radial direction of the rotation spindle 31 swells rearward from the rotation spindle and that the shape as seen in the direction along the shaft center P of the rotation spindle 31 is circular around the shaft center P of the rotation spindle 31.COPYRIGHT: (C)2012,JPO&INPIT【課題】回転支軸と一体回転自在な支持プレートに連結された複数本の扱歯支持杆を備えた脱穀扱胴において、特別な補強部材を付加せずとも脱穀反力に耐えやすく、かつ製作容易な状態で得る。【解決手段】回転支軸31の半径方向に沿った断面での形状が回転支軸前方向きに膨出した形状となるように、かつ回転支軸31の軸芯Pに沿った方向視での形状が回転支軸31の軸芯Pを中心とした円形となるように成形した第1補強リブ42と、回転支軸31の半径方向に沿った断面での形状が回転支軸後方向きに膨出した形状となるように、かつ回転支軸31の軸芯Pに沿った方向視での形状が回転支軸31の軸芯Pを中心とした円形となるように成形した第2補強リブ43とを、第1補強リブ42と第2補強リブ43が回転支軸31の半径方向に連なって並ぶ状態で支持プレート39に一体成形して設けてある。【選択図】図4
