PURPOSE: To suck satisfactorily fuel.

CONSTITUTION: A suction port 9 is bent in a position eccentric to the rotary center line C of a rotor and provided with an introducting hole 24 extending from the outer peripheral surface of the rotor facing a peripheral groove like fuel supply port 6a to a bent part 23 and an exhaust hole 25 extending from the bent part to a fuel suction path 8. An open port part 26 of the introducing hole 24 communicating to the fuel supply port 6a on the outer peripheral surface 4a of the rotor is opened toward the rotary direction side of the rotor slong a tangent T to the outer peripheral surface 4a on the open port part 26. A force for separating suction fuel in the suction port 9 radially from the rotary center line C by a centrifugal force accompanying the rotation of the rotor acts on the suction fuel, while since the suction port has the bent part 23, the inner surface of the bent part particularly resists against the centrifugal force and only the component of the centrifugal force acts on the suction fuel. When the open port part 26 collides with the fuel in the fuel supply port 6a along with the rotation of the rotor, the fuel in the fuel supply port 6a gets liable to be sucked into the open port part 26 by a reaction force to the component of the rotary force.