Patent ID: 8286546

Claim:
A fuel system comprising: a fuel pump including a reciprocating member; and a drive shaft including a lobe member engaged with the reciprocating member of the fuel pump to linearly displace the reciprocating member and drive the fuel pump, the lobe member including a first lobe having a first opening flank driving a first compression stroke of the fuel pump through engagement with the reciprocating member and having a profile providing a constant velocity for the linear displacement of the reciprocating member for a portion of the first compression stroke, the lobe member including a base circle having the first lobe extending radially outward therefrom and the first lobe including a closing flank for guiding a return stroke of the fuel pump through engagement with the reciprocating member, the first opening flank having a starting point at a first location on the base circle and the closing flank having an ending point at a second location rotationally displaced from the first location, the first opening flank extending along a greater angular extent of the base circle than the closing flank.