Abstract: An oil pump fixation detecting apparatus includes an oil pump, a discharge state switching unit, a target oil pressure setting unit, a pressure regulator, and a fixation determining unit. The discharge state switching unit performs control of switching a discharge state of the oil pump from a full-discharge state to a partial-discharge state. The fixation determining unit determines that the oil pump is not fixed in the full-discharge state in a case where oil pressure in a high-pressure oil passage has dropped by a predetermined value or more within a predetermined time, and determines that the oil pump is fixed in the full-discharge state in a case where the oil pressure in the high-pressure oil passage does not drop by the predetermined value or more.

Abstract: An internal gear pump includes an outer rotor, an inner rotor, and a pump housing. The inner rotor is rotatably disposed inside the outer rotor having internal teeth, forms pump chambers between the outer rotor and the inner rotor, and has external teeth. The pump housing has an inhalation port, a discharge port, and a first notch formed within a first land surface that extends from an end of the inhalation port to an end of the discharge port. The first notch is formed along a projection trajectory obtained by projecting a trajectory of chip points on the first land surface, where each chip point is a middle point between a corresponding one of the internal teeth and a corresponding one of the external teeth at a location at which the internal and external teeth substantially face each other above the first land surface and are closest to each other.

Abstract: An oil pump fixation detecting apparatus includes an oil pump, a discharge state switching unit, a target oil pressure setting unit, a pressure regulator, and a fixation determining unit. The discharge state switching unit performs control of switching a discharge state of the oil pump from a full-discharge state to a partial-discharge state. The fixation determining unit determines that the oil pump is not fixed in the full-discharge state in a case where oil pressure in a high-pressure oil passage has dropped by a predetermined value or more within a predetermined time, and determines that the oil pump is fixed in the full-discharge state in a case where the oil pressure in the high-pressure oil passage does not drop by the predetermined value or more.

Abstract: An internal gear pump includes an outer rotor, an inner rotor, and a pump housing. The inner rotor is rotatably disposed inside the outer rotor having internal teeth, forms pump chambers between the outer rotor and the inner rotor, and has external teeth. The pump housing has an inhalation port, a discharge port, and a first notch formed within a first land surface that extends from an end of the inhalation port to an end of the discharge port. The first notch is formed along a projection trajectory obtained by projecting a trajectory of chip points on the first land surface, where each chip point is a middle point between a corresponding one of the internal teeth and a corresponding one of the external teeth at a location at which the internal and external teeth substantially face each other above the first land surface and are closest to each other.