Abstract: An extrusion assembly, which fits into a hydraulic press, includes an upper die plate and a lower die plate mounted to one another by die guide posts. A lead bar is coupled to upper die plate at one end and a hydraulic chuck at its other end and includes helical grooves on its surface that mate with helical protrusions on lead nuts. Hydraulic chuck selectively retains a mandrel assembly. A die shell and insert are mounted concentrically with mandrel assembly and receive a gear blank. A bottom rest assembly is located below die shell and is positioned to receive mandrel assembly. An ejection assembly is positioned between bottom rest assembly and a hydraulic cylinder and includes ejector pins. As hydraulic press pushes lead bar axially through gear blank, lead nuts impart a rotational motion to lead bar, which causes mandrel to move with a helical motion as it is pressed into and through gear blank. Chuck then releases mandrel assembly onto bottom rest assembly and lead bar is retracted.

Abstract: A variable engine valve control system and method of operation thereof wherein each of the reciprocating engine valves is hydraulically or electrically controlled and can vary its lift schedule for various engine operating conditions. During part load operation of the engine, the intake valve is opened and the exhaust valve is closed during the exhaust stroke, prior to a piston's top dead center position, so that the intake port receives exhaust gas, which is then returned to the cylinder during the intake stroke to eliminate the need for an external exhaust gas recirculation system and to improve fuel evaporation into the intake air. Further, during part load, the intake valve is closed before the end of the intake stroke and the intake air is heated by a heat exchanger prior to entry into the cylinder to eliminate the need for air throttling without compromising the compression ratio and ignition characteristics.