The working principle of the bucket elevator is relatively simple. The bulk material enters the aggregate bin at the bottom of the bucket lifting machine, and the motor drives the reducer to drive the sprocket or drive the drum to rotate. According to the friction principle, the driving drum drives the traction member (traction belt or traction chain) to rotate, and the bucket fixed on the traction member scooped the material from the collecting bin and lifted it with the traction member to the top of the bucket lift machine. Then, the bucket with the traction member around the top of the driving drum to turn downward, unload the material, dump the material into the discharge trough and discharge from the discharge port. The winnowing bucket is rotated to achieve continuous conveying of materials.