Shaft sealing structure and shaft sealing method of roots blower for vacuum evaporator, and vacuum evaporation apparatus

摘要

PPROBLEM TO BE SOLVED: To provide a shaft seal structure and shaft seal method of a roots blower for a vacuum evaporator, and a vacuum evaporation device, preventing grease or lubricating oil of bearings from being contaminated with steam by using oil seals as shaft seals and discharging the steam leaked from the inside of a rotor chamber to the outside to prevent the steam from leaking to a bearing side. PSOLUTION: In the shaft seal structure, a pair of cocoon type rotors 24A, 24B and the bearings 26a-26d rotatably supporting opposite ends of respective rotating shaft 25A, 25B of the rotors 24A, 24B, respectively, are contained in a casing, and the oil seals 32a-32d are installed between the rotating shafts and the casing at parts between the respective bearings 26a-26d and the rotor chamber 31, respectively. An air filling hole 33 for communicating with the outside air and introducing the outside air into the casing and a discharge hole 34 for discharging the air introduced in the casing are formed in the casing between each oil seal 32a-32d and the corresponding bearing 26a-26d. The discharge hole 34 is connected to a vacuum pump 12 through a vacuum line 11b. PCOPYRIGHT: (C)2011,JPO&INPIT