Patent ID: 7913929

Claim:
A module, direct fuel injector comprising: a fuel side sub-assembly comprising: valve body structure defining a main flow passage there-through and an outlet opening, the valve body structure including a seating surface at a distal end thereof, a needle disposed in the main flow passage, the needle having first and second ends, the second end having a sealing surface associated with the seating surface, the needle being movable between a closed position with the sealing surface engaging the seating surface to prevent fuel from passing through the outlet opening, and an open position with at least a portion of the needle moving outwardly from the distal end of the valve body structure with the sealing surface being disengaged from the seating surface to permit fuel to pass through the outlet opening, a spring, disposed in the main flow passage, constructed and arranged to bias the needle to the closed position, manifold structure coupled to the valve body structure, a portion of the manifold structure having a bore there-through with the first end of the needle extending outwardly from the bore and beyond an end surface of the portion of the manifold structure, the manifold structure including inlet passage structure in communication with the bore and with the main fuel passage so that fuel supplied to the inlet passage structure will pass through the main flow passage and through the outlet opening when the needle is in the open position, and a bellows in the bore and constructed and arranged to prevent fuel from exiting the bore near the first end of the needle, a dry side sub-assembly comprising: a piezo stack coupled to the manifold structure and constructed and arranged to change length when voltage is applied thereto, the piezo stack being associated with the first end of the needle so that when the length of the piezo stack changes, the needle moves from the closed position to the open position thereof, and a thrust nut and a thrust ring associated with the piezo stack, the thrust nut being threadedly engaged with the manifold structure, coupling the piezo stack to the manifold structure.