Rotary apparatus for coating annular workpieces without hanging point

The utility model discloses an annular workpiece hook-free point-painting rotary device which comprises a wheel box, a hollow shaft, a rotary joint, a rotary through pipe, an inside water-through pipe and a water cooling system, wherein, the transmission shaft of the wheel box drive the hollow shaft through a gear set; the rotary through pipe and the rotary joint are respectively fixed at the two ends of the hollow shaft; one end of the inside water-through pipe of the rotary joint extends to the end head of the rotary through pipe, and the other end is communicated with the water cooling system, so as to guide the cooled water to the tail end of the rotary through pipe, thereby ensuring the whole rod to have cooling circulating water which has even and constant temperature. The device can improve the uniformity of the annular workpiece hook-free point-painting layer, enables the thickness of the surface even painting layer to be easy to control, enhances the product quality, is suitable for painting the rela