Sliding cam follower

A fuel pump, comprising:

• a camshaft assembly including an offset lobe having a lobe surface, the lobe surface defining a first arcuate surface and the camshaft assembly configured to rotate about a first axis;
• a barrel unit disposed on the fuel pump, the barrel unit having a second axis substantially perpendicular to the first axis;
• a plunger disposed within the barrel unit, the plunger including a foot having a second arcuate surface;
• and
• a follower disposed between the foot of the plunger and the lobe surface, the follower having a third arcuate surface in contact with the second arcuate surface and a fourth arcuate surface in contact with the first arcuate surface.