Fuel injector assembly with pressure-equalized valve seat

A fuel injector assembly having a valve with a valve seat in which pressure variations at the valve seat are reduced when the valve is in a closed position, said fuel injector assembly comprising:

• a fuel injector body;
• a valve disposed in said fuel injector body, said valve having a valve element and a valve seat, said valve element being movable in an opening direction and in a closing direction between a closed position in which said valve element is in contact with said valve seat and an open position in which said valve element is not in contact with said valve seat;
• actuator means for causing said valve element to be reciprocated between said open position and said closed position;
• and
• fluid supply means for supplying fluid to said valve comprising first cavity means in contact with said valve element which exerts a fluid pressure on said valve element that is non-constant about the periphery of said valve element and second cavity means fluidly connected to said first cavity means, said second cavity means being annularly disposed around a periphery of said valve element to reduce fluid pressure variations about the periphery of said valve element.

A fuel injector assembly having a valve with a valve seat in which pressure variations at the valve seat are reduced when the valve is in a closed position, said fuel injector assembly comprising:

• a fuel injector body;
• a valve disposed in said fuel injector body, said valve having valve element means and a valve seat, said valve element means being reciprocable in an opening direction and in a closing direction between a closed position in which said valve element means is in contact with said valve seat and an open position in which said valve element means is not in contact with said valve seat, said valve element means having an end adjacent said valve seat;
• actuator means for causing said valve element means to be reciprocated between said open position and said closed position;
• fluid supply means for supplying fluid to said valve at a pressure of at least 140,000 MPa (20,000 psi), said fluid supply means causing a fluid pressure to be exerted on said valve element means that is non-constant about the periphery of said valve element means;
• and
• pressure-equalizing means comprising annular cavity means, disposed around a periphery of said valve element means, for causing a substantially equal fluid pressure to be exerted about the periphery of said end of said valve element means adjacent said valve seat.