It is applied to transmission sealing at the sputtering section of PVD coating lines with flange-type connection. One end of the shaft connects to the synchronous pulley at the atmospheric end, and the other end connects to the mechanism inside the vacuum chamber, maintaining torque transmission and vacuum sealing. It is suitable for vacuum sealing under the conditions of -5 Pa vacuum degree, ambient temperature within 280°C and 0-500 rpm rotating speed. During operation, maintain pure water cooling state and control the water pressure at 0.2-0.8 MPa.