Fuel pump with auxiliary pumping chamber

摘要

A fuel pump includes a pumping plunger reciprocable within a bore formed in a pump housing under the influence of a cam drive arrangement. The cam drive arrangement includes a reciprocable tappet member, a surface associated with the tappet member defining, in part, an auxiliary pumping chamber. A flow path interconnects the auxiliary pumping chamber and the bore such that fuel displaced from the auxiliary pumping chamber, in use, can be supplied through the flow path to the bore.