Rotary fuel pump and combination fuel injector/spark plug

Abstract

A rotary fuel pump and fuel injectors including a combination spark plug/fuel injector are described. The rotary fuel pump includes a camshaft carrying an eccentric cam. A plurality of rocker arms follow the cam and cause a plurality of plungers in fuel pumps to reciprocate pumping fluid with each plunger stroke. The rocker arms may include cooperating radially inner and outer rocker arms interposed between the eccentric cam and the plungers and having pivots which may be moved with respect to one another to varying the displacement of the plunger strokes. The fuel injector includes a housing having a plunger bore and a fuel inlet bore in fluid communication with one another. A plunger reciprocates within the plunger bore and has a valve seat is biased closed against a valve seat on the housing by elastomeric O-rings. The O-rings seal between the plunger and the plunger bore. Pressurized fluid pressing upon the plunger may overcome the bias allow fuel to sprayed from the plunger bore. An insulator may be provided between the housing and the plunger and with a fuel inlet bore connecting the fuel bore of the housing with the plunger bore. Electrical current and pressurized fuel may be supplied to the fuel injector to causing the fuel to be sprayed from the plunger bore and a spark to be produce across a spark gap formed between the housing and plunger.