| 摘要 |
An oil pump includes a rotor (30), an outer peripheral member (40) accommodating the rotor (30), a first plate, and a second plate. A discharge passage (52K) through which hydraulic fluid is discharged is connected to a discharge port (10ex) of the first plate. A first pressure gradually-changing groove (10M) and a second pressure gradually-changing groove (20M) are formed such that a second flow passage area is larger than a first flow passage area, the first flow passage area being a flow passage area of the first pressure gradually-changing groove (10M) of the first plate, at a position at which the first pressure gradually-changing groove (10M) communicates with a transfer chamber (30V) passing through a sealed region, and the second flow passage area being a flow passage area of the second pressure gradually-changing groove (20M) of the second plate, at a position at which the second pressure gradually-changing groove (20M) communicates with the transfer chamber (30V) passing through the sealed region. |
