Internal gear pump

Abstract

Provided is an internal gear pump requiring fewer machining steps, allowing inexpensive manufacture, and offering high safety from the standpoint of function. The internal gear pumpcomprises: a trochoidin which an inner rotorhaving a plurality of outer teeth is eccentrically and rotatably accommodated in an outer rotorhaving a plurality of inner teeth, the outer teeth meshing with the inner teeth, and in which a suction-side chamber for suctioning liquid and a discharge-side chamber for discharging liquid that has been suctioned into the suction-side chamber are formed in between the inner teeth and outer teeth; a casingin which is formed a recessfor accommodating the trochoid; and a coverfor closing off the recessof the casing. At least some of the casingis a body injection-molded from a resin composition. The invention also comprises a groovein a portion of the recessof the casingin which the outer periphery is sealed, with a sealing ringinstalled therein, and bushingsmade from sintered metal that are provided integrally during injection molding in bolt fixing hole portions.