FUEL INJECTOR, NOZZLE TIP AND VALVE NEEDLE FOR A FUEL INJECTOR, FUEL INJECTION SYSTEM AND LARGE COMBUSTION ENGINE

The invention discloses a fuel injector (1) for injecting a fuel into a combustion chamber (211) of a large combustion engine (200). The fuel injector (1) comprises an injector body (3) with a fuel supply line (16) and a fuel supply chamber (6), a nozzle tip (10) having a spray hole (11), and a valve needle (13) biased by a spring (14) towards a closed position against a valve seat (15). The valve needle (13) is configured to open and close a fluid connection between the fuel supply chamber (6) and the spray hole (11), wherein the spring (14) is arranged in a spring chamber (50). The fuel supply line (16) is fluidly connected or connectable to the spring chamber (50) and to the fuel supply chamber (6). The invention further discloses a nozzle tip (10) for a fuel injector (1), a valve needle (13) for a fuel injector (1), a fuel injection system (100) and a large combustion engine (200).