Patent ID: 6409096
Filing Date: 2002-06-25
Classification: F02M,Y02T

Abstract:
A fuel injector for injecting gaseous fuel into a cylinder of an engine, the fuel injector adapted to be driven by hydraulic signals of a hydraulic fluid, comprising:a support housing having a gas passageway therein for communicating gaseous fuel to the cylinder of the engine; a piston mounted in a piston control chamber actuated by the hydraulic signals; a valve in the housing driven by the piston between open and closed positions corresponding with opening and closing the gas passageway to the cylinder of the engine; a collection chamber in the support housing, hydraulic fluid adapted to leak past the piston into the collection chamber, leaked oil being communicated to an outlet for removal; wherein the piston is mounted in the control chamber without seals, with a small clearance between the piston and the control chamber, a controlled amount of hydraulic fluid adapted to continuously leak past the piston; and a gas seal between the valve and the support housing, the gas seal engaging the valve for preventing gaseous fuel from leaking from the gas passageway into the collection chamber, wherein the collection chamber provides a fail safe in which gas leakage past the gas seal is tolerated, any gas leakage being joined with leaked hydraulic fluid for removal and separation via the outlet.