Patent ID: 6068461
Filing Date: 2000-05-30
Classification: F04C

Abstract:
A vane type rotary pump comprising:a stator housing;a cam ring formed at its inner periphery with a cam surface and mounted with the stator rotor;a pair of end well structures fitted to opposite ends of the cam ring to form a pump cavity in the cam ring;a drive shaft rotatably mounted within the stator housing and extending into the interior of the pump cavity through one of the end wall structures;a rotor contained within the cam ring and mounted on the drive shaft for rotation therewith;a plurality of circumferentially equally spaced vanes positioned in the body of the rotor to move radially outward from the rotor and cooperating with the cam surface of the cam ring to form a plurality of expandable pump chambers,at least one suction port formed on an inside face of one of the wall structures at a portion where the pump chambers expand as the vanes move radially outward; andat least one discharge port formed on the inside face thereof at a portion where the pump chambers contract as the vanes move radially inward, the discharge port being configured so as to be formed with at least one bearded groove which is tapered from a forward end of the discharge port in a direction opposite a rotational direction of the rotor,wherein said at least one bearded groove is formed with an introducing portion the surface of which is inclined into the interior of the discharge port, said introducing portion comprising at least first and second differently configured portions which are continuously connected with each other.