SCREENING DEVICE OF THRESHER

摘要

PROBLEM TO BE SOLVED: To provide a screening device of a thresher equipped with winnowers for separately sending screening air to a crude screening unit and a fine screening unit of a shaking separator in a state in which a screening processing is accurately and efficiently carried out while reducing third losses even though the amount of materials to be screened is large or small. SOLUTION: A damper 51 for changing the air flow of screening air fed by a second winnower 22 is installed to be freely operated to shake at the blow port of the second winnower for feeding the screening air to a rough screening unit of a shaking screening device 10. By installing a speed change pulley 27 to the drive shaft of a first winnower 21 and changing the drive speed of the first winnower 21, the screening air flow fed to a fine screening unit of the shaking screening device 10 by the first winnower 21 is changed. The speed change pulley 27 and a damper 51 are constituted to be operated in mutual connection both in the air flow-increasing side and decreasing side.