| 主权项 |
1. An internal gear pump comprising:
a housing having a pump chamber; an inner rotor arranged in the pump chamber, rotating about a first rotational axis and having external teeth on an outer end thereof; an outer rotor arranged in the pump chamber, rotating about a second rotational axis and having internal teeth on an inner end thereof; a suction port that is formed at the housing and through which a fluid is sucked into the pump chamber; a discharge port that is formed at the housing and through which the fluid is discharged from the pump chamber; a suction path in communication with the suction port; and a discharge path in communication with the discharge port, wherein the pump chamber includes an inner wall extending in a rotating direction of the outer rotor, the inner wall includes a suction region located close to the suction port with respect to a boundary, which is a plane including the first rotational axis and the second rotational axis, and a discharge region located close to the discharge port with respect to the boundary, the suction region includes a first suction region extending in a circumferential direction towards the suction path from a pressing point, which is located at a position in the suction region and where the outer rotor is pressed when the internal gear pump is in operation, and a second suction region located between the first suction region and the discharge region, a groove that enlarges a clearance between the outer rotor and the inner wall is formed at least at a portion of the first suction region, and the groove is not formed in the second suction region. |
