REOIL-FREE TYPE VACUUM PUMP

摘要

PURPOSE:To limit a rotor's axis-directional movement of abrasion prevention by connecting a clearance between either one of rotor's both sides and a side plate to the outer space of a bearing on the side plate and a passage installed inside the rotor shaft. CONSTITUTION:A reoil-free style vane type vacuum pump has a small clearance between either one both side faces of a rotor 3 and a side plate 2a or 2b. The air space outside the bearing 5 of a rotor shaft 4 is connected to the above- mentioned clearance through a communicating passage 13 inside the rotor shaft 4. Then the pressure at both sides of the rotor 3 is equalized, eventually with no pushing the rotor 3 to the axial direction, and therefore the abrasion to be generated between the rotor or a vane and the side plate 2a or 2b is reduced.