A dual-fuel fuel injector, having: a first nozzle needle for discharge of liquid fuel via a first nozzle arrangement; and a multiplicity of second nozzle needles, arranged around the first nozzle needle and controlled in terms of axial stroke, for discharge of gaseous fuel via a second nozzle arrangement. Each of the second nozzle needles has for controlling the stroke thereof, a respective control chamber in the injector which can be charged with and relieved of pressure by a control fluid. The dual-fuel fuel injector has an annular duct which can be charged with and relieved of pressure by the control fluid. The dual-fuel fuel injector is designed such that, for controlling the stroke of the second nozzle needles, the control chambers for the second nozzle needles are charged with and relieved of pressure by the control fluid proceeding from the annular duct.

An electrically actuated control valve has three mouths and three operating positions, in which the three mouths includes a first mouth for inlet of a working fluid, and a second mouth and a third mouth for outlet of the working fluid. The three operating positions include a first operating position in which a passage of fluid from the first mouth to the second mouth and the third mouth is enabled, a second operating position in which a passage of fluid from the first mouth to only one of said second and third mouths is enabled, and a third operating position in which the passage of fluid from the first to the second mouth and the third mouth is disabled. The control valve includes an electric or electromagnetic actuator for controlling the passage of fluid from the first mouth to the second and third mouths providing the aforesaid three operating positions.

The invention relates to a fuel injector (1) for operating with combustible gas. The fuel injector has a plurality of combustible-gas nozzle valve elements (9), and the stroke of each of the combustible-gas nozzle valve elements can be controlled by means of a paired hydraulic piston control assembly (55) of the fuel injector, wherein each piston control assembly is formed by two control chambers (59, 61) and a piston section (63) on the combustible-gas nozzle valve element paired with the piston control assembly, said piston section separating the control chambers in such a way that their volumes can be varied, and the fuel injector is designed to control the stroke of the combustible-gas nozzle valve elements in tandem using a 3/2-way valve (67), by means of which the hydraulic pressure in one of the two control chambers of the piston control assemblies is controlled.

The invention relates to a fuel injector (1) for operating with combustible gas. The fuel injector has a plurality of combustible-gas nozzle valve elements (9), and the stroke of each of the combustible-gas nozzle valve elements can be controlled by means of a paired hydraulic piston control assembly (55) of the fuel injector, wherein each piston control assembly is formed by two control chambers (59, 61) and a piston section (63) on the combustible-gas nozzle valve element paired with the piston control assembly, said piston section separating the control chambers in such a way that their volumes can be varied, and the fuel injector is designed to control the stroke of the combustible-gas nozzle valve elements in tandem using a 3/2-way valve (67), by means of which the hydraulic pressure in one of the two control chambers of the piston control assemblies is controlled.

A fuel injector capable of injecting a plurality of different fuels in a single fuel injection event includes a body including a primary fuel path and a pilot fuel path and a first plunger in fluid communication with the pilot fuel path. The fuel injector also includes a second plunger in fluid communication with the primary fuel path and with the pilot fuel path, a hydraulic control chamber within the pilot fuel path, and an injection valve at which the primary fuel path and the pilot fuel path connect to each other.

A fuel system includes a plurality of fuel injectors each having an injection control valve assembly, a direct operated nozzle check, a high pressure nozzle supply passage, and a check control chamber. A common drain conduit fluidly connects to each of the plurality of fuel injectors to receive drained actuating fluid. A plurality of pressure regulating valves each having a static geometry are positioned fluidly between the common drain conduit and the check control chamber in one of the plurality of fuel injectors. Operating a fuel system according to the present disclosure includes limiting cross-talk between injectors in the fuel system.

A flow control actuator includes at least one side wall, an upstream wall coupled to an upstream end of the side wall, a downstream cap coupled to a downstream end of the side wall, the downstream cap comprising at least one orifice disposed therein, at least one fuel injector disposed in at least one of the upstream wall, and the sidewall, the fuel injector dispersing fuel into the interior of the flow control actuator, and at least one oxidizer inlet disposed in at least one of the upstream wall and the sidewall, the at least one oxidizer inlet introducing an oxidizer into the interior of the flow control actuator. The flow control actuator includes at least one external fuel injector disposed adjacent to the side wall. The fuel from the fuel injector and oxidizer from the oxidizer inlet ignite in the interior of the flow control actuator.

A flow control actuator includes at least one side wall, an upstream wall coupled to an upstream end of the side wall, a downstream cap coupled to a downstream end of the side wall, the downstream cap comprising at least one orifice disposed therein, at least one fuel injector disposed in at least one of the upstream wall, and the sidewall, the fuel injector dispersing fuel into the interior of the flow control actuator, and at least one oxidizer inlet disposed in at least one of the upstream wall and the sidewall, the at least one oxidizer inlet introducing an oxidizer into the interior of the flow control actuator. The flow control actuator includes at least one external fuel injector disposed adjacent to the side wall. The fuel from the fuel injector and oxidizer from the oxidizer inlet ignite in the interior of the flow control actuator.

A filter assembly for filtering hydraulic fluid in a hydraulically actuated fuel injector is disclosed. The filter assembly includes a plurality of first rollers and a plurality of second rollers. The first rollers are parallelly disposed one after the other, and define first axes disposed in a first plane. The second rollers are parallelly disposed one after the other, and define second axes disposed in a second plane. The first plane is parallel to the second plane. Further, each second roller is disposed between a consecutively arranged pair of first rollers to define one or more filtration zones for filtering the hydraulic fluid.

A filter assembly for filtering hydraulic fluid in a hydraulically actuated fuel injector is disclosed. The filter assembly includes a plurality of first rollers and a plurality of second rollers. The first rollers are parallelly disposed one after the other, and define first axes disposed in a first plane. The second rollers are parallelly disposed one after the other, and define second axes disposed in a second plane. The first plane is parallel to the second plane. Further, each second roller is disposed between a consecutively arranged pair of first rollers to define one or more filtration zones for filtering the hydraulic fluid.