Fuel pump for motor vehicle

An open-vane regenerative turbine pump comprising:

• a housing,
• an impeller mounted on the housing for rotation about a centerline thereof having a body and a plurality of paddle-like open-vane type vanes extending radially out from said body,
• an annular pump channel in said housing around the periphery of said impeller and around said vanes having a pair of sidewalls each in a plane perpendicular to said centerline,
• a stripper on said housing in said pump channel closely adjacent said impeller,
• an inlet port in said housing connected to said pump channel closely adjacent a first side of said stripper,
• a discharge port in said housing connected to said pump channel closely adjacent a second side of said stripper,
• a vapor collection chamber in said housing radially inboard of said pump channel and separated therefrom by a pair of annular bosses on said housing closely adjacent respective ones of a pair of opposite sides of said impeller,
• a pair of radial vapor ports in respective ones of said pair of annular bosses between said inlet port and said discharge port each providing flow communication between said pump channel and said vapor collection chamber and each having a downstream side facing in the direction of said inlet port swept-back in a downstream direction, and
• a pair of steps on respective ones of said sidewalls of said pump channel each sweeping in a downstream direction for smooth transition with a corresponding one of said radial vapor ports from a point on an outside diameter of said annular pump channel upstream of said corresponding one of said pair of radial vapor ports to an inside diameter of said pump channel at said downstream side of said corresponding one of said radial vapor ports to gradually reduce the cross sectional area of said pump channel from a maximum upstream of said swept-back steps to a minimum at said downstream sides of said radial vapor ports.