Vane type vacuum pump

Abstract

A vane type vacuum pump has a discharge port for discharging suctioned air, and a reed valve part that opens and closes the discharge port. The reed valve part includes a first reed valve that is installed to cover the opening of the discharge port, and a second reed valve that is superposed with the first reed valve. The first reed valve and the second reed valve have different resonance frequencies by having different thicknesses.

1 . A vane type vacuum pump that inhales a gas and discharges the gas from a discharge port, the vane type vacuum pump comprising:
 a first reed valve that is installed at the discharge port; and   a second reed valve that is superposed with the first reed valve and has a resonance frequency which is different from that of the first reed valve.   
     
     
         2 . The vane type vacuum pump according to  claim 1 , wherein
 the first reed valve and the second reed valve have different thicknesses.   
     
     
         3 . The vane type vacuum pump according to  claim 1 , wherein
 the first reed valve and the second reed valve have different shapes.   
     
     
         4 . The vane type vacuum pump according to  claim 1 , wherein
 the first reed valve and the second reed valve are formed with different materials.   
     
     
         5 . The vane type vacuum pump according to  claim 1 , further comprising:
 a stopper member that is provided at an outer side of the first reed valve and the second reed valve to limit a valve open amount of the first reed valve and the second reed valve.