| 摘要 |
PROBLEM TO BE SOLVED: To provide a Roots blower with a safety valve capable of obtaining approximately constant air quantity even when pressure is changed and operable by small power. SOLUTION: In the Roots blower B having the safety valve 20 and used in a low pressure region, the tare type safety valve 20 is provided integrally with a housing 24 for storing a valve element 30 in a pipe part 21 connectable to a discharge pipe 7 of the Roots blower B. A lower end part of the valve element 30 is brought into contact with a valve seat 26 formed on an upward communication port 25 communicated with inside of the discharge pipe 7, so that the contact state can be held by the tare. A coil spring 35 serving as a spring member for chattering prevention is fitted to a rear part of the valve element 30. When gas pressure inside the pipe part 21 is raised instantaneously, the pressure pushes up the valve element 30 and opens the communication port 25, so as to discharge gas flowing in the housing 24 from a discharge port 37 to outside. COPYRIGHT: (C)2009,JPO&INPIT
|
