| 摘要 |
PROBLEM TO BE SOLVED: To provide a vacuum pump with a simple structure capable of reducing noise generated in an exhaust port when an intake pressure of a compression element is lowered to a predetermined use pressure. SOLUTION: A check valve 40 for narrowing an opening area of the exhaust port 18a when pressure in a vacuum tank is lowered to a usual usage pressure band area is arranged for the exhaust port 18a formed in a pump cover 18. COPYRIGHT: (C)2010,JPO&INPIT |
