Abstract: A two-stage variable-displacement oil pump includes a casing having a suction port for suctioning oil stored in an oil tank and a discharge port for discharging, to a main gallery; an outer cam ring rotatably installed with respect to a pivot shaft provided inside the casing and having a rotary chamber therein; a rotor installed to be eccentric relative to the outer cam ring, rotating in concert with a rotation of a driving shaft, and including a plurality of vanes radially and slidably installed on an outer circumferential surface of the rotor; a support spring having one end contacting a spring support part formed on an outer side surface of the cam ring and the other end contacting an inner side surface of the casing; and a regulating chamber provided between the outer cam ring and the casing.

Abstract: A two-stage variable-displacement oil pump includes a casing having a suction port for suctioning oil stored in an oil tank and a discharge port for discharging, to a main gallery; an outer cam ring rotatably installed with respect to a pivot shaft provided inside the casing and having a rotary chamber therein; a rotor installed to be eccentric relative to the outer cam ring, rotating in concert with a rotation of a driving shaft, and including a plurality of vanes radially and slidably installed on an outer circumferential surface of the rotor; a support spring having one end contacting a spring support part formed on an outer side surface of the cam ring and the other end contacting an inner side surface of the casing; and a regulating chamber provided between the outer cam ring and the casing.

Abstract: A vane pump is configured to discharge a working fluid introduced into one side of a rotary chamber formed between an outer cam ring and a rotor to the other side of the rotary chamber, wherein a through slit extending in a circumferential direction of the outer cam ring is formed in a corresponding portion of the outer cam ring corresponding to the side to which the working fluid is introduced into the rotary chamber.