| 摘要 |
PURPOSE: To provide a vacuum pump used for manufacturing a semiconductor that eliminates damage of a pump casing, peripheral equipment, and the like and improves reliability and safety by preventing breakdown of a rotor due to corrosion. CONSTITUTION: A balancer 20 is attached to the outer peripheral surface of the rotor 2 so as to face to the inside of a gas passage. A balancer body 21 in the balancer 20 is supported for the outer peripheral surface of the rotor 2 via a fragile part 22 for a corrosive gas so as to have a balancing function and a corrosion detecting function of the rotor 2. The fragile part 22 of the balancer 20 damages due to corrosion to drop the balancer 20 before an influence of the corrosive gas appears in rotor blades 1 and the rotor 2, so that an unbalance state of the rotor 2 is forcibly produced. The unbalance state of the rotor 2 is detected by a sensor and the pump is stopped, thereby preventing the damage of the vacuum pump itself and the peripheral equipment. |
