Abstract: A variable oil pump includes a pump housing, an oil pump rotor accommodated in the pump housing, an adjustment member accommodated in the pump housing and configured to adjust a discharge amount of oil discharged from the oil pump rotor by displacing in a state where the adjustment member holds the oil pump rotor from an outer circumferential side in such a manner that the oil pump rotor is rotatable, and a guide portion including a guide hole provided at the adjustment member and a pin provided at the pump housing and engaging with the guide hole. The guide portion is configured to guide a displacement of the adjustment member relative to the pump housing by allowing the guide hole and the pin to engage with each other. The variable oil pump includes a drain passage configured to drain oil accumulated in the guide hole.

Abstract: A variable oil pump includes a pump housing, an oil pump rotor accommodated in the pump housing, an adjustment member accommodated in the pump housing and configured to adjust a discharge amount of oil discharged from the oil pump rotor by displacing in a state where the adjustment member holds the oil pump rotor from an outer circumferential side in such a manner that the oil pump rotor is rotatable, and a guide portion including a guide hole provided at the adjustment member and a pin provided at the pump housing and engaging with the guide hole. The guide portion is configured to guide a displacement of the adjustment member relative to the pump housing by allowing the guide hole and the pin to engage with each other. The variable oil pump includes a drain passage configured to drain oil accumulated in the guide hole.

Abstract: An internal gear pump includes a housing having a pump chamber in which an inner rotor and an outer rotor are arranged. A suction port in communication with a suction path and a discharge port in communication with a discharge path are formed at the housing. The pump chamber includes an inner wall having a suction region at a suction port-side and a discharge region at a discharge port-side. The suction region includes a first suction region extending towards the suction path from a pressing point, where the outer rotor is pressed when the internal gear pump is in operation, and a second suction region 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 in the first suction region, but the groove is not formed in the second suction region.

Abstract: The oil pump driving control apparatus includes an internal combustion engine driving source transmitting a driving force of an internal combustion engine to an oil pump that includes an inner rotor and an outer rotor, a motor separately provided from the internal combustion engine driving source and driving and rotating the oil pump, and a driving source switching portion switching a driving source of the oil pump to at least one of the motor and the internal combustion engine driving source based on an oil temperature and a rotation number of the internal combustion engine.

Abstract: An internal gear pump includes a housing having a pump chamber in which an inner rotor and an outer rotor are arranged. A suction port in communication with a suction path and a discharge port in communication with a discharge path are formed at the housing. The pump chamber includes an inner wall having a suction region at a suction port-side and a discharge region at a discharge port-side. The suction region includes a first suction region extending towards the suction path from a pressing point, where the outer rotor is pressed when the internal gear pump is in operation, and a second suction region 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 in the first suction region, but the groove is not formed in the second suction region.

Abstract: In an auto-tensioner, a damping device is used to control a fluid communication between a first fluid chamber and a second chamber for adjusting an engagement of an idler pulley with a belt-shaped power transmission member in such a manner that when a tension thereof is decreased, a quick propulsive movement of the idler pulley to the belt-shaped power transmission member is allowed by the first urging member, while when the tension is increased, the idler pulley is retracted gradually from the belt-shaped power transmission member by a registration of the belt-shaped power transmission member.