IC engine fuel injection pump - has resilient piston or cylinder portion whose deflection balances pressure-induced increase of leak gap width

摘要

The combustion engine fuel injection pump comprises a pump piston (8) in a cylinder (9) bore (10) which between them define the high-pressure chamber (11). The piston clearance provides a leak gap (42) between the piston periphery (40) and the cylinder wall. One portion (44) of the piston, or two portions of the cylinder, are arranged to permit resilient deformation. The deflection of the portion(s) (44) approximately balances the pressure-induced increase of the leak gap width. The resilient portion (44) of the piston may consist of an annular groove (41) in the end face (43) of the piston.