INSCRIBED GEAR PUMP

摘要

PROBLEM TO BE SOLVED: To provide an inscribe gear pump which can vary a discharge amount of a fluid by changing a position of an outer rotor with which an inner rotor contacts, and is facilitated in manufacture while keeping high accuracy during the manufacture.SOLUTION: An inscribed gear pump is composed of: an inner rotor 3; an outer rotor 4 rotating while having a prescribed eccentric amount e with respect to its rotation center P3; an outer ring 5 for rotatably wrap-holding the outer rotor 4, and having at least three cam protrusions 53 formed thereon; a pump housing A having a rotor chamber 1; protrusive wall face parts 6 which are formed at an internal peripheral side face of the rotor chamber, and are formed in the same number as that of the cam protrusions 53; and operation means 7 for oscillating the outer ring 5. Positions of the protrusive wall face parts 6 are set so that the operation means 7 moves the diameter center P5 of a wrap-holding internal peripheral part 51 of the outer ring 5 along a trace circle Q with the eccentric amount e as a radius with respect to the rotation center P3 of the inner rotor 3.