A fuel injector is provided and may include an injector body and an injector valve. The injector body may define a longitudinally extending chamber and may include a first intake port, a second intake port and a fuel injection port. The injector valve may be disposed within the chamber and may include a longitudinally extending aperture in fluid communication with the longitudinally extending chamber. The injector valve may be configured to prevent fluid communication between the first intake port and the second intake port, and may be configured to prevent fluid communication between the fuel injection port and the second intake port.

A check valve driving device for injecting gas, which enables an accurate operation of a check valve for injecting gas and long-term usage by enhancing durability, comprises: an upper portion fixing block which moves vertically by coupling onto a yoke repeating vertical movements; a lower portion fixing block which is coupled to a prechamber at a lower portion of the yoke; a roller which is rotatably coupled onto the upper portion fixing block, and of which a center portion diameter is bigger than diameters of both end portions; a guide, which is rotatably coupled onto the lower portion fixing block, for rotating when a curved surface on one side thereof comes into contact with the roller moving vertically; an operation piece, which is rotatably coupled onto the lower portion fixing block, wherein a front end of the operation piece moves vertically in accordance with the rotation of the guide; and a pressing rod which is coupled to the front end of the operation piece, and which is lowered in accordance with the lowering of the front end of the operation piece.

A fuel injector of a fuel injection system for delivering gaseous fuel to an internal combustion engine comprises: an injector nozzle having a valve needle that is movable within a bore of the injector nozzle; a needle control valve; a first fluid supply network for conveying the control fluid from a first injector inlet to an inlet of the needle control valve; a second fluid supply network for conveying the gaseous fuel from a second injector inlet to a delivery chamber, defined around the valve needle in the bore of the injector nozzle, for injection into the engine; and one or more sealant chambers for sealing respective leakage paths of the second fluid supply network, each leakage path extending between respective adjacent bodies of the fuel injector and the respective sealant chamber being defined at interfacing surfaces of those bodies to enclose that leakage path.

A fuel injector for a gaseous fuel and having: an injection nozzle; a support body with a tubular shape, which is provided with a feeding channel therein, ending in the injection nozzle; an injection valve; a tubular sleeve, which is arranged around an end part of the support body, entirely contains the shutter therein, and ends with the injection nozzle; and an actuator, which is configured to move the shutter. An injection duct, which is created when the injection valve is in the open position, has a converging initial segment, in which an area of the injection duct progressively decreases from a first maximum value at the beginning of the injection duct to a minimum value, and a diverging final segment, in which the area of the injection duct increases from the minimum value until reaching a second maximum value.