Dual fuel system for internal combustion engine and leakage limiting seal strategy for same
AssigneeCaterpillar Inc.
InventorsHoisan Kim, Cory Andrew Brown, Glenn B. Cox
Life of this patent
Estimating the term…
Abstract
A dual fuel system includes liquid and gaseous fuel supplies and a fuel injector in fluid communication therewith. A gaseous fuel check in the fuel injector forms a leak path with a fuel injector body between gaseous and liquid fuel passages, and a leakage limiting seal is positioned about the gaseous fuel check and deformable into sealing contact with the gaseous fuel check responsive to an increase in a pressure drop from the liquid fuel passage to the gaseous fuel passage in the fuel injector.
Claims19
A dual fuel system for an internal combustion engine comprising:
- a liquid fuel supply;
- a gaseous fuel supply;
- a fuel injector including an injector body defining a liquid fuel passage in fluid communication with the liquid fuel supply, a gaseous fuel passage in fluid communication with the gaseous fuel supply, and a gaseous fuel nozzle outlet;
- the fuel injector further including a gaseous fuel check guided within the injector body between retracted and advanced positions at which fluid communication is open and blocked, respectively, between the gaseous fuel passage and the gaseous fuel nozzle outlet, and the injector body and the gaseous fuel check together forming a leak path for controlled leakage of liquid fuel from the liquid fuel passage to the gaseous fuel passage responsive to a pressure drop therebetween;
- and
- the fuel injector further including a leakage limiting seal having an outer surface exposed to a fluid pressure of the liquid fuel passage, an inner surface exposed to a fluid pressure of the leak path, and being positioned about the gaseous fuel check such that the leakage limiting seal deforms into sealing contact with the gaseous fuel check responsive to an increase in the pressure drop.
A fuel injector for a dual fuel system in an internal combustion engine comprising:
- an injector body defining a liquid fuel passage extending between a liquid fuel inlet and a liquid fuel outlet, and a gaseous fuel passage extending between a gaseous fuel inlet and a gaseous fuel nozzle outlet;
- a gaseous fuel check guided within the injector body between retracted and advanced positions at which fluid communication is open and blocked, respectively, between the gaseous fuel passage and the gaseous fuel nozzle outlet, for controlling injection of gaseous fuel from the gaseous fuel nozzle outlet into a cylinder in the internal combustion engine, and the injector body and the gaseous fuel check together forming a leak path from the liquid fuel passage to the gaseous fuel passage;
- a leakage limiting seal having an outer surface exposed to a fluid pressure of the liquid fuel passage, and an inner surface exposed to a fluid pressure of the leak path;
- and
- the leakage limiting seal being in a first state where the inner surface has a clearance with the gaseous fuel check and permits controlled leakage of the liquid fuel through the leak path, and being deformable to a second state at which the inner surface is in sealing contact with the gaseous fuel check to limit the leakage, responsive to an increase in a pressure drop from the liquid fuel passage to the gaseous fuel passage.
A method of limiting migration of liquid fuel to a gaseous fuel side of a dual fuel system in an internal combustion engine comprising the steps of:
- increasing a pressure drop from a liquid fuel passage to a gaseous fuel passage in fluid communication with one another via a leak path formed by a gaseous fuel check and an injector body in a fuel injector of the dual fuel system;
- deforming a leakage limiting seal into sealing contact with the gaseous fuel check, responsive to the increase in the pressure drop;
- and
- reducing leakage of liquid fuel through the leak path via the sealing contact.
Dependencies are inferred from the claim text.