Abstract: A fuel injector includes an upper housing having an outer peripheral surface; a nozzle tip with a nozzle opening which serves as an outlet to fuel from the fuel injector; and a valve needle which is selectively moveable between a first position which prevents fuel flow and a second position which permits fuel flow. The fuel injector also includes an inlet sleeve which includes an inner peripheral surface which circumferentially surrounds, and mates with, the outer peripheral surface of the upper housing. The inlet sleeve is fixed to the upper housing, thereby preventing relative movement between the inlet sleeve and the upper housing. The inlet sleeve includes external threads which are configured to mate with complementary internal threads of a nut which secures a fuel supply conduit to the upper housing.

Abstract: A fuel injector includes an upper housing having an outer peripheral surface; a nozzle tip with a nozzle opening which serves as an outlet to fuel from the fuel injector; and a valve needle which is selectively moveable between a first position which prevents fuel flow and a second position which permits fuel flow. The fuel injector also includes an inlet sleeve which includes an inner peripheral surface which circumferentially surrounds, and mates with, the outer peripheral surface of the upper housing. The inlet sleeve is fixed to the upper housing, thereby preventing relative movement between the inlet sleeve and the upper housing. The inlet sleeve includes external threads which are configured to mate with complementary internal threads of a nut which secures a fuel supply conduit to the upper housing.

Abstract: A gaseous fuel injector for supplying gaseous fuel to a fuel consuming device includes a fuel inlet, a fuel outlet, a fuel passage for communicating the gaseous fuel from the fuel inlet to the fuel outlet and a valve assembly for selectively preventing and permitting the gaseous fuel to pass from the fuel inlet to the fuel outlet. The valve assembly includes a valve seat with a plurality of apertures for providing fluid communication therethrough and a valve extending along a valve axis for selectively preventing and permitting flow of the gaseous fuel through the valve seat. Each one of the plurality of apertures is a radially extending slot and the plurality of apertures is arranged in a polar array centered about the valve axis.

Abstract: A gaseous fuel injector is provided with a fuel inlet, a fuel outlet, and a conduit for communicating fuel from the inlet to the outlet. A valve and valve seat is provided for selectively preventing and permitting fuel to pass from the fuel inlet to the fuel outlet. The valve seat has a plurality of apertures for providing fluid communication therethrough. The valve has a sealing face for selectively engaging and disengaging the valve seat to selectively prevent and permit fuel from passing therethrough. The valve seat includes a raised seating surface for sealing against the sealing face when the valve is engaged with the valve seat. The raised seating surface is defined by at least one wall that continuously surrounds each aperture. Each wall is in continuous fluid communication with the entirety of each wall downstream of the sealing face when the valve is engaged with the valve seat.

Abstract: Seal means for sealing a bipolar plate to a membrane in a PEM fuel cell stack. The seal includes a thin layer of a cross-linkable silicone composition disposed between the bipolar plate and the membrane. The layer is applied as a liquid to either the plate or the membrane and preferably is polymerized prior to assembly of the stack. A preferred means for applying the composition to the bipolar plate is screen printing. Preferably, the layer has a thickness between 0.001 and 0.005 inch. The resulting fuel cell stack exhibits superior leak resistance. In a currently preferred embodiment, a layer of the silicone composition is provided at interfaces between a membrane and both an anode side and a cathode side of a bipolar plate.

Abstract: Apparatus and method for substantially reducing or eliminating pressure pulsations caused by the opening and closing of fuel injectors. A preferred embodiment provides a restriction orifice adjacent the inlet end of a fuel injector filter of a respective fuel injector.

Abstract: Apparatus and method for substantially reducing or eliminating pressure pulsations caused by the opening and closing of fuel injectors. A preferred embodiment provides a restriction orifice adjacent the inlet end of a fuel injector filter of a respective fuel injector.

Abstract: A method for forming a fuel cell assembly including the pre-final-assembly step of forming a plurality of fuel cell sub-assembly modules, each module including a predetermined number of individual fuel cell repeating units, for example, ten. Each module may be leak and performance tested and certified prior to inclusion in the final fuel cell stack, thus limiting potential rework to only an individual module and only before assembly of the final stack. Preferably, each module is assembled on an assembly fixture having alignment rods, using a combination of resilient gasketing and RTV to seal between the elements. The assembled module is then placed under compression while the silicone is cured.

Abstract: A lower filter for a fuel injector includes a disk having an annular shape and including a plurality of filter holes. The disk is positioned upstream of a valve guide of an internal valve assembly without contacting the valve guide. The disk prevents internally generated contaminants contained in fuel flowing through the filter holes from reaching a valve guide area and a sealing area of the internal valve assembly. By installing the lower filter upstream of the valve guide and without contact to the valve guide, interference with the guidance and reciprocal movement of the valve is avoided. Application of the lower filter in fuel injectors may reduce the occurrence of injector failures by reducing the number of stuck open conditions in injectors and by reducing the number of hydro lock engine incidents without interference with the valve guide.

Abstract: An internal lower filter for a fuel injector includes a self-supporting guide guiding a reciprocably activated valve of an internal valve assembly of a fuel injector and a plurality of filter holes formed in said guide filtering fuel flowing through the fuel injector and preventing contaminants contained in the fuel from entering a sealing area of the internal valve assembly. Incorporating the guide filter in accordance with the invention in a fuel injector enables capturing particles or contaminants, generated within the fuel injector during assembly or during operation, before entering the sealing area of an internal valve assembly. Accordingly, failure modes of the injector, such as a stuck open condition that may lead to a hydraulic lock of the engine, can be reduced. By forming the filter holes in a typically used ball guide, no changes are required to the currently used assembly line equipment or the current assembly process.

Abstract: A fuel rail assembly includes a fuel injector socket having a cylindrical end for receiving an injector and a boxed end for orienting and positioning the injector relative to the engine cylinder. A boxed shape end cap is fitted over the boxed end of the socket thereby supporting the socket. Planar saddle members are disposed on each side of the end cap and radiused edges are fitted to the cylindrical surface of the fuel distribution tube. A jump tube communicates fuel from the fuel distribution tube to the fuel injector socket. A bracket defines a sole plate for the assembly, for attachment to an engine head, and includes a generally planar surface for locating against the planar surface of the saddle members. Components of the fuel rail assembly are first assembled loosely on a fixture, then joined together as the fuel rail assembly.

Abstract: A precision fuel rail assembly for direct fuel injection comprising a plurality of formed parts first assembled and positioned loosely on a precision fixture, then joined (e.g. tack welded), by applying a BFM on all joints forming a “green” assembly and firing in a brazing oven, to produce a precision assembly formed from stainless steel parts. A bracket defining a sole plate for the assembly may be formed as a continuous element or a plurality of individual fuel rail brackets. Flanged sockets are attached to the bracket at locations corresponding to the fuel injector locations on an engine bank. Bolt holes are provided along the centerline of the sockets and fuel injectors. The bracket supports a fuel distribution tube via saddle elements disposed between the bracket and the tube. A jump tube supplies fuel from the distribution tube to each socket.

Abstract: A thermoplastic carrier sheet is die-cut to have a size and shape matching that of a PEM bipolar plate. A plurality of holes are punched in the carrier sheet in the pattern of gasket beading to be formed subsequently. In a mold, liquid gasket resin fills the mold on both sides of the carrier sheet to form the gasket, flowing through the holes in the sheet and thereby causing the gasket to become mechanically attached to the sheet. A carrier element having a flange portion substantially identical with the outer profile of the bipolar plates is laminated to the sheet edge. During assembly of a fuel cell, the carrier element automatically positions the gasket correctly on the plate and prevents the gasket from twisting or shifting. In a currently preferred embodiment, a membrane electrode assembly is attached within an appropriate opening in the carrier sheet.

Abstract: A method for attaching a gasket to a non-gasketed bipolar plate for a PEM fuel cell, including the steps of making a pattern of the gasket; preparing the bipolar plate surface; priming the bipolar plate surface for adhesive according to the gasket pattern; aging the primer coat; screen-printing an adhesive coat onto the primer according to the gasket pattern; positioning the gasket face-down in a mirror-image fixture having channels in the form of the gasket; positioning the bipolar plate face down onto the fixture and gasket; applying pressure to the plate to adhere the gasket thereto in the adhesive-coated areas; removing the plate and gasket subassembly from the fixture; and curing the adhesive to provide a gasketed bipolar plate.

Abstract: Seal means for sealing a bipolar plate to a membrane in a PEM fuel cell stack. The seal includes a thin layer of a cross-linkable silicone composition disposed between the bipolar plate and the membrane. The layer is applied as a liquid to either the plate or the membrane and preferably is polymerized prior to assembly of the stack. A preferred means for applying the composition to the bipolar plate is screen printing. Preferably, the layer has a thickness between 0.001 and 0.005 inch. The resulting fuel cell stack exhibits superior leak resistance. In a currently preferred embodiment, a layer of the silicone composition is provided at interfaces between a membrane and both an anode side and a cathode side of a bipolar plate.

Abstract: A thermoplastic carrier sheet is die-cut to have a size and shape matching that of a PEM bipolar plate. A plurality of holes are punched in the carrier sheet in the pattern of gasket beading to be formed subsequently. In a mold, liquid gasket resin fills the mold on both sides of the carrier sheet to form the gasket, flowing through the holes in the sheet and thereby causing the gasket to become mechanically attached to the sheet. A carrier element having a flange portion substantially identical with the outer profile of the bipolar plates is laminated to the sheet edge. During assembly of a fuel cell, the carrier element automatically positions the gasket correctly on the plate and prevents the gasket from twisting or shifting. In a currently preferred embodiment, a membrane electrode assembly is attached within an appropriate opening in the carrier sheet.

Abstract: Seal means for sealing a bipolar plate to a membrane in a PEM fuel cell stack. The seal includes a thin layer of a cross-linkable silicone composition disposed between the bipolar plate and the membrane. The layer is applied as a liquid to either the plate or the membrane and preferably is polymerized prior to assembly of the stack. A preferred means for applying the composition to the bipolar plate is screen printing. Preferably, the layer has a thickness between 0.001 and 0.005 inch. The resulting fuel cell stack exhibits superior leak resistance. In a currently preferred embodiment, a layer of the silicone composition is provided at interfaces between a membrane and both an anode side and a cathode side of a bipolar plate.

Abstract: A method for attaching a gasket to a non-gasketed bipolar plate for a PEM fuel cell, including the steps of making a pattern of the gasket; preparing the bipolar plate surface; priming the bipolar plate surface for adhesive according to the gasket pattern; aging the primer coat; screen-printing an adhesive coat onto the primer according to the gasket pattern; positioning the gasket face-down in a mirror-image fixture having channels in the form of the gasket; positioning the bipolar plate face down onto the fixture and gasket; applying pressure to the plate to adhere the gasket thereto in the adhesive-coated areas; removing the plate and gasket subassembly from the fixture; and curing the adhesive to provide a gasketed bipolar plate.