Variable-capacity oil pump

A variable displacement oil pump comprising:

• a housing having a pump accommodating portion;
• an adjusting member movably provided in the pump accommodating portion;
• a pump member accommodated inside the adjusting member and driven and rotated by a drive shaft passing through a rotation center that is eccentric to a center of an inner circumference of the adjusting member, wherein a plurality of working chambers are defined between the pump member and the adjusting member, oil is sucked into some working chambers of the plurality of working chambers through a suction portion that is provided so as to straddle the adjusting member in a radial direction of the drive shaft according to rotation of the pump member, and oil in the some working chambers of the plurality of working chambers is discharged through a discharge portion that is provided so as to straddle the adjusting member in the radial direction according to the rotation of the pump member;
• a control hydraulic chamber formed between the pump accommodating portion and the adjusting member in the radial direction, wherein oil discharged from the discharge portion is introduced into the control hydraulic chamber, and the control hydraulic chamber adjusts an eccentric amount of the adjusting member;
• an urging member forcing the adjusting member in a direction in which the eccentric amount of the center of the inner circumference of the adjusting member from the rotation center of the drive shaft increases by contacting the adjusting member;
• and
• a stopper portion provided at the adjusting member, coming into contact with a stopper contact portion provided at the pump accommodating portion by receiving an urging force of the urging member and restraining movement of the adjusting member in the direction in which the eccentric amount Δ of the adjusting member increases, wherein the stopper portion is provided at a position that does not overlap the suction portion in a circumferential direction of rotation of the drive shaft on the rotation center, wherein
• the adjusting member pivots on a pivot provided at the pump accommodating portion on the basis of an internal pressure of the control hydraulic chamber and the urging force of the urging member, and
• the control hydraulic chamber includes:
• a first control hydraulic chamber whose volume increases when oil discharged from the discharge portion is introduced into the first control hydraulic chamber and the adjusting member moves in a direction in which the eccentric amount of the center of the inner circumference of the adjusting member from the rotation center of the drive shaft decreases;
• and
• a second control hydraulic chamber whose volume increases when oil discharged from the discharge portion is introduced into the second control hydraulic chamber and the adjusting member moves in the direction in which the eccentric amount of the center of the inner circumference of the adjusting member from the rotation center of the drive shaft increases, and
• the stopper portion is provided at a position that overlaps the discharge portion when viewed from an axial direction along the drive shaft, and is located at a position at which a distance from the stopper portion to the second control hydraulic chamber is shorter than a distance from the stopper portion to the pivot in the circumferential direction.