Fixture for machining wind power main shaft

The utility model relates to a clamp for machining a wind power main shaft. The clamp comprises a chuck and a rack. The clamping head comprises a clamping jaw support, and the clamping jaw support is a hollow hexagonal prism. Air cylinders are fixed to the three side faces of the clamping jaw support. A guide shaft is fixed on the clamping jaw bracket at the horizontal position of each air cylinder; a clamping jaw is arranged at the extending end of each air cylinder; a rotating shaft penetrates through the center of the clamping jaw support, and the rotating shaft rotates to enable the clamping jaw support to rotate correspondingly. The rack is arranged on the lathe, a sleeve is arranged at the top of the rack, and a shaft shell penetrates through the sleeve; an axially moving shaft sleeve is arranged in the shaft shell, a screw rod is arranged in one end of the shaft sleeve, and the rotating shaft is sleeved in the other end of the shaft sleeve; and an adjusting nut is fixed in the shaft sleeve. The tool ca