Patent attributes
A vane pump includes a rotor chamber; a rotor accommodated in the rotor chamber; a plurality of vanes attached to the rotor, each vane having a leading end adapted to make sliding contact with an inner peripheral surface of the rotor chamber. The vane pump includes working compartments surrounded by inner surfaces of the rotor chamber, an outer peripheral surface of the rotor and the vanes; an inlet port through which a working fluid is drawn into a working compartment; and an outlet port through which the working fluid is discharged from a working compartment. A cutout portion is formed in a leading end portion of each vane on each of at least one of a leading and a trailing side of the leading end portion, the leading end of each vane having a width smaller than that of a base end portion of each vane.
