Patent ID: 6619939
Filing Date: 2003-09-16
Classification: F04C

Abstract:
A rotary pump comprising:a casing which has a circular inner circumferential surface, a rotor which rotates about a center of said inner circumferential surface of said casing as a central axis, a partition plate which is installed so as to be movable in and out of said casing so that a tip end of said partition plate comes into contact with an outer circumferential surface of said rotor, a spring which drives said partition plate so that said partition plate is in constant contact with said rotor, an intake port formed in said casing, said intake port being positioned after said partition plate with respect to a direction of rotation of said rotor, and a discharge port formed in said casing, said discharge port being positioned before said partition plate with respect to said direction of rotation of said rotor, wherein said pump is characterized in that a communicating portion tat communicates between an intake port side and an discharge port side is provided in said partition plate, and said rotor has a substantially equilateral-triangular shape that makes a sliding contact with said inner circumferential surface of said casing inner, two of said partition plates are provided so as to face each other on a straight line tat passes through a center of said rotor, and two of said intake ports and two said discharge ports are provided.