Co-axial quill assembly retainer and dual fuel common rail engine using same

摘要

A dual fuel common rail engine supplies pressurized natural gas and liquid diesel fuel at different pressures through a co-axial quill assembly for direct injection from a single fuel injector into an engine cylinder. Each coaxial quill assembly includes a matched pair of inner and outer quills that are chosen to have dimensions that allow both quills to sealingly engage each fuel injector at a common conical seat responsive to a clamping force applied along an axis. Matched pairs of inner and outer quills are retained together during pre-installation handling with a retainer that is left between the inner and outer quills after installation in an engine.

主权项

1. A coaxial quill assembly for a dual fuel common rail fuel system comprising:
a block defining a liquid fuel passage that opens into a quill chamber through a conical seat, and defines a gaseous fuel passage that opens into the quill chamber outside of the conical seat; an inner quill that defines a liquid fuel conduit extending between a first end and a second end, and the first end including an annular spherical surface resting in contact with, but unattached to, the conical seat; an outer quill with a hollow interior separating a first end from a second end, and the first end being received in the quill chamber; a gaseous fuel conduit extending between an outer surface of the inner quill and an inner surface of the outer quill; an annular seal for preventing gaseous fuel from escaping from the gaseous fuel conduit between the block and the outer quill; a retainer in contact with the outer surface of the inner quill and the inner surface of the outer quill for maintaining the inner quill with the outer quill during pre-installation handling, wherein the retainer and the inner surface of the outer quill define an edge filter having a plurality of filter passages that are distributed around, and oriented perpendicular to a centerline of the retainer; and a gage line at the second end of the inner quill extending a predetermined target distance beyond a gage line at the second end of the outer quill so that the inner and outer quills seat on a common conical seat responsive to a predetermined load on the block along an centerline.