Single-cylinder high pressure pump for common-rail fuel injection systems in IC engines has guide cylinder with ball loosely guided on end of pump piston

摘要

The pump has a housing (1) with pump piston (5) and pressure spring-loaded cylinder (4) with cam drive (8). A ball (20) is loosely held on the end (6) of the piston facing the cam drive. The ball is guided inside a cup (21), which moves in the pump housing at the piston end, and has a base (22) facing the cam drive. The cup is shaped like a circular cylinder (19) and its base has an aperture (23) for the ball. Hardness and diameter of the ball are adapted to operational Hertzian stress.