Fuel injector having three stages

An engine system comprising:

• a combustion chamber for combusting an air-fuel mixture;
• a fuel line to supply a high pressure fuel for combustion in the combustion chamber;
• a junction line to port a portion of exhaust gas from the combustion chamber;
• and
• a fuel injector including an injector body and an inner element disposed within and rotatable relative to the injector body, a prechamber defined within the inner element between portions of the inner element and the injector body, the inner element rotatable to selectively:
• align a first passage between the prechamber and the junction line to allow exhaust gas to pass into the prechamber, and
• align a second passage between the prechamber and the fuel line to pass a fuel into the prechamber, and
• align one or more injector nozzle connectors between the prechamber and the one or more injector nozzles to inject a fuel-exhaust gas mixture from the prechamber into the combustion chamber.

A fuel injector comprising:

• an injector body defining passages therethrough, including:
• one or more exhaust gas passages,
• one or more fuel passages, and
• one or more injector nozzles;
• an inner element having a chamber wall defining a pre-chamber therein, the chamber wall having passages therethrough, including:
• one or more exhaust gas nozzles,
• one or more fuel nozzles, and
• one or more injector nozzle connectors;
• and
• the inner element disposed substantially inside the injector body and movable relative to the injector body to selectively align:
• the one or more exhaust gas nozzles, with the one or more exhaust gas passages,
• the one or more fuel nozzles with the one or more fuel passages, and
• the one or more injector nozzle connectors with the one or more injector nozzles in order to inject a mixture of fuel and exhaust gas into a combustion chamber of an engine.

A method, comprising:

• rotating an inner fuel injector element relative an injector body a first amount and aligning an injector exhaust gas passage with an exhaust gas source;
• rotating the inner element a second amount and aligning a fuel passage with a fuel source;
• and
• rotating the inner element a third amount and aligning injector nozzle connectors with injector nozzles to inject a fuel and exhaust gas mixture from a pre-chamber to a cylinder.