Abstract: An apparatus includes a housing, a solenoid coil disposed within the housing, a pole member, and an armature configured to move from a first position to a second position when the solenoid coil is energized. A contact surface of the armature is spaced apart from a contact surface of the pole member by a first distance when the armature is in the first position, and a second distance when the armature is in the second position. The housing, the pole member and the armature collectively define a flux path characterized by a first reluctance when the armature is in the first position and a second reluctance when the armature is in the second position. The difference between the first reluctance and the second reluctance is less than about thirty percent of the value of the first reluctance.

Abstract: An apparatus includes a housing, a solenoid coil disposed within the housing, a pole member, and an armature configured to move from a first position to a second position when the solenoid coil is energized. A contact surface of the armature is spaced apart from a contact surface of the pole member by a first distance when the armature is in the first position, and a second distance when the armature is in the second position. The housing, the pole member and the armature collectively define a flux path characterized by a first reluctance when the armature is in the first position and a second reluctance when the armature is in the second position. The difference between the first reluctance and the second reluctance is less than about thirty percent of the value of the first reluctance.

Abstract: A fuel injector has a housing extending along a longitudinal axis between an inlet and an outlet. A seat assembly is disposed in a body proximate the outlet. The seat assembly includes a flow portion and a securement portion. The flow portion extends along the longitudinal axis between a first surface and an orifice disk retention surface at a first length. The flow portion has a seat orifice extending therethrough and an orifice disk coupled to the orifice disk retention surface so that the orifice plate is aligned in a fixed spatial axial orientation with respect to the flow portion. The securement portion extends along the longitudinal axis away from the orifice disk retention surface at a second length greater than the first length. A method of maintaining a fixed spatial axial orientation and dimensional symmetry of at least one of the seat and orifice disk in the body is disclosed.

Abstract: A modular fuel injector that includes a coil group subassembly and a valve group subassembly. The coil group subassembly is independently testable. The valve group subassembly is independently testable and includes a tube assembly having a longitudinal axis extending between a first tube end and a second tube end, and a seat assembly disposed in the tube assembly proximate the second tube end. The seat assembly includes a flow portion and a securement portion. The flow portion extends along the longitudinal axis between a first surface and an orifice disk retention surface at a first length. The flow portion has a seat orifice extending therethrough and an orifice disk coupled to the orifice disk retention surface so that the orifice plate is aligned in a fixed spatial orientation with respect to the flow portion. The securement portion extends along the longitudinal axis away from the orifice disk retention surface at a second length greater than the first length.

Abstract: An electromagnetically operable fuel injector for a gaseous fuel injection system of an internal combustion engine, the injector having a generally longitudinal axis, which includes a ferromagnetic core, a magnetic coil at least partially surrounding the ferromagnetic core and an armature magnetically coupled to the magnetic coil and being movably responsive to the magnetic coil. The armature actuates a valve closing element in the form of a valve needle which interacts with a fixed valve seat of a fuel valve and is movable away from the fixed valve seat when the magnetic coil is excited. The fixed valve seat defines an aperture of predetermined dimension for passage of fuel therethrough, the armature having a generally elongated shape and a generally central opening for axial reception and passage of gaseous fuel from a fuel inlet connector positioned adjacent thereto.

Abstract: An electromagnetic actuator is provided and includes upper and lower electromagnets. Each electromagnet includes a lamination core assembly comprising a plurality of individual stacked laminations. Upper and lower housings are provided, each having opposing end walls. The core assembly of the upper electromagnet is disposed between the end walls of the upper housing and the core assembly of the lower electromagnet is disposed between the end walls of the lower housing. An armature is mounted for movement between the core assemblies. Spacer structure is disposed between the core assemblies and contacts each of the core assemblies to prevent the core assemblies from moving towards each other. A pin provides a connection between a lamination core assembly and the end walls of an associated housing. Each housing has a contact surface between the end walls and each of the core assemblies includes a solid core member defining a central portion of each core assembly.

Abstract: A method of joining a magnetic armature of an electromagnetic actuator to a shaft is provided. The method includes holding the armature stationary while spinning the shaft. The spinning shaft is then pressing against the stationary armature such that friction between the shaft and the armature causes a portion of the armature and a portion of the shaft to melt and define a weld joint. The weld joint is permitted to cool thereby joining the shaft to the armature.