Armature with shear stress damper

摘要

An electro-mechanical fuel injector comprising: a housing and valve seat including a valve setting surface and a metering orifice disposed at a lower end of the housing. An armature assembly is movable relative to the valve seating surface for opening and closing the metering orifice and includes an armature and a pin extending therefrom and adapted to engage the seating surface; a coil assembly and spring are provided to move the armature assembly in a direction to open and close the metering orifice. The injector includes a fluid chamber defined upstream of the metering orifice, in surrounding relation to a portion of the armature assembly. A damping assembly is also provided, movable with the armature assembly, for generating a viscous shear damping force by interacting with the wall of the chamber.