Abstract: The process for investment casting of complex shapes has historically had 6 basic steps in it. Depending upon the path taken, these discrete steps have been reduced to either 5 steps, or to 2 steps, discarding the unwanted steps. Instead of having to generate the shape of each sacrificial pattern, the process generates either (A) a male tree containing a plurality of sacrificial patterns, already on their runners, onto which a mold shell can be formed, or, (B) a female shell, made of a refractory material, and forming internally the outside surfaces of the plurality of patterns and runners. This process removes both capital expenditure for tooling and process time by up to 90%. By removing several lengthy, time-dependant steps from the process the part cost and lead time are reduced.

Abstract: An air boost device such as a turbocharger, wherein the compressor wheel thereof is re-designed to permit die inserts (20), which occupy the air passage and define the blades (4, 5) during a process of forming a wax pattern (21) of a compressor wheel, to be pulled without being impeded by the blades. This modified blade design enables the automated production of wax patterns (21) using simplified tooling. The compressor wheel improves low cycle fatigue, withstands high temperatures and temperature changes, and permits operation at high boost pressure ratio while, on the other hand, having low weight, low inertial drag, and high responsiveness.

Abstract: A housing (410, 510, 610, 700, 800, 900) for a turbocharger (400, 500, 600) is provided. The housing (410, 510, 610, 700, 800, 900) has an impeller chamber (403, 503, 603), diffuser (450, 550, 650, 750, 850, 950) and scroll (420, 520, 620, 720, 820, 920) in fluid communication with each other. The diffuser (450, 550, 650, 750, 850, 950) can have a curved shape and/or a bend (455) in proximity to a tip (408, 508, 608, 609) of the impeller (405, 505, 605). The curved shape can be defined by one or more radii of curvature (RC, RC1, RC2). The diffuser (450, 550, 650, 750, 850, 950) can extend in a radial direction that is non-orthogonal to the center line of the turbocharger (400, 500, 600). The housing (410, 510, 610, 700, 800, 900) can be for a compressor section of the turbocharger (400, 500, 600).

Abstract: A housing (410, 510, 610, 700, 800, 900) for a turbocharger (400, 500, 600) is provided. The housing (410, 510, 610, 700, 800, 900) has an impeller chamber (403, 503, 603), diffuser (450, 550, 650, 750, 850, 950) and scroll (420, 520, 620, 720, 820, 920) in fluid communication with each other. The diffuser (450, 550, 650, 750, 850, 950) can have a curved shape and/or a bend (455) in proximity to a tip (408, 508, 608, 609) of the impeller (405, 505, 605). The curved shape can be defined by one or more radii of curvature (RC, RC1, RC2). The diffuser (450, 550, 650, 750, 850, 950) can extend in a radial direction that is non-orthogonal to the center line of the turbocharger (400, 500, 600). The housing (410, 510, 610, 700, 800, 900) can be for a compressor section of the turbocharger (400, 500, 600).

Abstract: The process for investment casting of complex shapes has historically had 6 basic steps in it. Depending upon the path taken, these discrete steps have been reduced to either 5 steps, or to 2 steps, discarding the unwanted steps. Instead of having to generate the shape of each sacrificial pattern, the process generates either (A) a male tree containing a plurality of sacrificial patterns, already on their runners, onto which a mold shell can be formed, or, (B) a female shell, made of a refractory material, and forming internally the outside surfaces of the plurality of patterns and runners. This process removes both capital expenditure for tooling and process time by up to 90%. By removing several lengthy, time-dependant steps from the process the part cost and lead time are reduced.

Abstract: A method of making an air boost device, wherein a compressor wheel incorporated therein is re-designed to permit die inserts (20), which occupy the air passage and define the blades (4, 5) during a process of forming a wax pattern (21) of a compressor wheel, to be pulled without being impeded by the blades. This modified blade design enables the automated production of wax patterns (21) using simplified tooling. These wax patterns (21) can be used in a large-scale investment casting process, and produce an economical cast titanium compressor wheel which performs aerodynamically at high boost pressure/RPM.

Abstract: A method of making an air boost device, wherein a compressor wheel incorporated therein is re-designed to permit die inserts (20), which occupy the air passage and define the blades (4, 5) during a process of forming a wax pattern (21) of a compressor wheel, to be pulled without being impeded by the blades. This modified blade design enables the automated production of wax patterns (21) using simplified tooling. These wax patterns (21) can be used in a large-scale investment casting process, and produce an economical cast titanium compressor wheel which performs aerodynamically at high boost pressure/RPM.

Abstract: An exhaust gas recirculation system for an internal combustion engine. The present invention includes a turbocharger, restrictor valve, and exhaust gas recirculation valve. The restrictor valve is upstream of the turbine of the turbocharger, and restricts the flow of exhaust gas into the turbine. This restriction results in an increase in pressure of the exhaust gas provided to the restrictor valve. The increased pressure exhaust gas is provided to the inlet of an exhaust gas recirculation valve which may be actuatable independently of the actuation of the restrictor valve. The restrictor valve may be modulated until exhaust pressure is greater than the pressure of the intake gas. The restrictor valve creates a pressure differential suitable for recirculating a portion of exhaust gas through the EGR valve and into the intake manifold of the engine.

Abstract: An exhaust gas recirculation system for an internal combustion engine. The present invention includes a turbocharger, restrictor valve, and exhaust gas recirculation valve. The restrictor valve is upstream of the turbine of the turbocharger, and restricts the flow of exhaust gas into the turbine. This restriction results in an increase in pressure of the exhaust gas provided to the restrictor valve. The increased pressure exhaust gas is provided to the inlet of an exhaust gas recirculation valve which may be actuatable independently of the actuation of the restrictor valve. The restrictor valve may be modulated until exhaust pressure is greater than the pressure of the intake gas. The restrictor valve creates a pressure differential suitable for recirculating a portion of exhaust gas through the EGR valve and into the intake manifold of the engine.