AIR PUMP

PURPOSE:To expand the passage cross section of a suction side and to increase the pump capacity by connecting one of the suction passage ports provided on both ends of a suction side passage to the suction port provided on one end of a housing and by connecting the other to the suction port through the internal space in a rotor. CONSTITUTION:Suction passage ports 30a, 30b are provided on both ends of a pump suction side passage 1b formed along the axial direction at the side of the pump chamber 1a in a housing 1, and one of them is connected to a suction port 27 provided on the rear cover 4 of the housing 1 and the other is connected to the suction port 27 through the internal space 31 extended in the axial direction in a rotor 5. Due to such a structure as to suck the air from both ends in relation to the suction side passage 1b, the passage cross section area at the suction side can be expanded, then the pump capacity can be increased and the pump can be made small-sized with less suction resistance, and furthermore, the air flow can be balanced and the efficiency and durability of the pump can be improved.