Patent ID: 6749272
Filing Date: 2004-06-15
Classification: F04C

Abstract:
A rotary pump comprising:an outer rotor having first and second axial end surfaces, the outer rotor being provided at an inner circumference thereof with inner teeth; an inner rotor having first and second axial end surfaces, the inner rotor being provided at an outer circumference thereof with outer teeth in mesh with the inner teeth so as to constitute a plurality of teeth gap portions therebetween; a drive shah fitted to the inner rotor for rotating the inner rotor; a casing provided with intake and discharge ports and a rotor room having first and second inner side surfaces opposed to each other, the inner and outer rotors being rotatably contained in the rotor room in such a manner that the first and second inner side surfaces of the rotor room face the first and second axial end surfaces of the outer and inner rotors, respectively, and the intake and discharge ports communicating with the teeth gap portions so that fluid is sucked from the intake port, compressed through the teeth gap portions and discharged from the discharge port when the drive shaft is driven; and a side sealing member disposed between the first axial end surfaces of the cuter and inner rotors and the first inner side surface of the rotor room to urge the outer and inner rotors toward the second inner side surface of the rotor room so that not only a side clearance between the first axial end surfaces of the outer and inner rotors and the first inner side surface of the rotor room is sealed but also a side clearance between the second axial end surfaces of the outer and inner rotors and the second inner side surface of the rotor room is sealed with a mechanical seal due to direct contact therebetween, wherein both of the second axial end surfaces of the outer and inner rotors and the second inner side surface of the rotor room are provided on entire surfaces thereof with radial line grinding stripes.