Patent ID: 7628595

Claim:
A method of operating a gas vane pump including: a housing, a rotor rotatably disposed within said housing and cooperating with said housing to define a pump chamber having a dimension in a radial direction of the rotor, which dimension varies in a rotating direction of the rotor, at least one vane portion held by said rotor movably relative to said rotor and dividing said pump chamber into a plurality of variable-volume chambers, and a lubricant supply passage formed through said housing and said rotor, said lubricant supply passage being closed when said rotor is placed at an angular position relative to said housing which angular position is outside a predetermined angular range, and opened for communication with an external lubricant supply source when said rotor is placed at an angular position within said predetermined angular range, wherein said vane pump is operated so as to satisfy a condition that when said rotor is stopped at an angular position relative to said housing, which angular position is within said predetermined angular range, a mass of a lubricant remaining in a lowest portion of said pump chamber is divided into a first portion and a second portion, by an initial divider vane which is provided by one of said at least one vane portion.