Improved tail wheel of mixture elevator

The improved tail wheel comprises a shell, a first rotating shaft, a first tail wheel body and a second tail wheel body, a fixing block is welded to one end of the inner wall of the shell, a box body is welded to the end, away from the fixing block, of the inner wall of the shell, a groove is formed in the fixing block, and a second rotating shaft is rotationally installed in the box body; a second bevel gear is fixedly installed on the top end face of the second rotating shaft, the first rotating shaft is rotatably installed in the box body, a first bevel gear is welded to the side end face of the first rotating shaft, a first tail wheel and a second tail wheel are fixedly installed on the first rotating shaft, and the first tail wheel is slidably sleeved with a second fixing piece. A first screw rod is slidably connected into the second fixing part and the first tail wheel in a sleeved mode, nuts are rotatably installed at the left end and the right end of the first screw rod, and the second tail wheel is s