Borgwarner Inc.

Stephen I Roby

David Michael Decker

Steven R McKinley

David George Grabowska

Paul K Anschel

Aleksandar Sekularac

Patrick Sweetland

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

Method for rapid generation of multiple investment cast parts such as turbine or compressor wheels

An air boost device such as a turbocharger, wherein the compressor wheel thereof is re-designed to permit die inserts (), which occupy the air passage and define the blades () during a process of forming a wax pattern () of a compressor wheel, to be pulled without being impeded by the blades. This modified blade design enables the automated production of wax patterns () 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.

Turbocharger including cast titanium compressor wheel

A compressor wheel () for an air boost device and a method for designing the wheel are provided. The compressor wheel () comprises a hub () and a plurality of blades () connected to the hub (). The plurality of blades () have a ratio (f/N) of natural frequency to maximum rotational speed of less than 4.0 and are made from a titanium alloy. The plurality of blades () can comprise a plurality of full blades () and a plurality of splitter blades ().

Low blade frequency titanium compressor wheel

A housing () for a turbocharger () is provided. The housing () has an impeller chamber (), diffuser () and scroll () in fluid communication with each other. The diffuser () can have a curved shape and/or a bend () in proximity to a tip () of the impeller (). The curved shape can be defined by one or more radii of curvature (R, R, R). The diffuser () can extend in a radial direction that is non-orthogonal to the center line of the turbocharger (). The housing () can be for a compressor section of the turbocharger ().

Turbocharger diffuser

A direction changing flow duct, for example, a compressor inlet duct () for a turbocharger compressor cover, wherein the direction of flow is made to change abruptly in a short distance. The direction changing segment is designed to provide a balanced output, optimize air flow, minimize pressure drop, and maintain compressor efficiency. This can be accomplished by providing a bulge () extending radially inwards into a first duct segment, outward bulges perpendicular to the inward bulge, for promoting flow attachment along the walls of the duct.

Duct for changing direction of flow, particularly for turbocharger  compressor inlet

A method of making an air boost device, wherein a compressor wheel incorporated therein is re-designed to permit die inserts (), which occupy the air passage and define the blades () during a process of forming a wax pattern () of a compressor wheel, to be pulled without being impeded by the blades. This modified blade design enables the automated production of wax patterns () using simplified tooling. These wax patterns () 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.

Method of making turbocharger including cast titanium compressor wheel

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. The restrictor valve may also be operated without recirculation of exhaust gas, such as during cold starting of a diesel engine so as to increase the load on the engine and decrease the warm-up time of the engine. Some embodiments of the present invention utilize an electronic controller for operating the restrictor valve and the EGR valve.

Growing community of inventors

Asheville, NC, United States of America

Stephen I Roby