Center frame special for large-diameter long axis machining

The utility model discloses a special center support for manufacturing big-diameter long shaft, and is provided to overcome the shortages that the three claws of center support of the prior common lathe are made from tin-bronze material, and have a large touch area to the big-diameter long shaft, and the friction is big to wear down the bronze bar, and the three claws are of low work efficiency. The utility model comprises an upper base, a lower base, and two supporting sleeves arranged on the lower base and a supporting sleeve arranged at the top of the upper base; the supporting sleeves face the center with adjustable length; supporting claws are respectively arranged at the facing centers of the supporting sleeves; the supporting claws are trolley which can roll on the long rotary shaft supported. Because the three claws of the long supported shaft on the center support are provided with trolleys, when the center support works, the trolleys roll on the outer circumference of the rotary long shaft for a tou