Abstract: This invention sets forth a commercially viable diesel combustion system that meets environmentally acceptable levels of NOx emissions (i.e. 0.2 g/bhp-hr or lower across a full map of engine speeds and loads) without the need for use of NOx aftertreatments, and simultaneously maintains engine-out PM emissions relatively close (e.g. with smoke levels at or below 3 BSN) to environmentally acceptable PM post-aftertreatment levels. The invention achieves these results by operating within a unique combination of parameters. These parameters comprise: (1) charge-air oxygen concentration below 16%, preferably between 10% and 15%, more preferably between 11% and 14%, and most preferably between 12% and 13.

Abstract: An improved apparatus for generating a variable compression ratio within an ICE includes a piston-in-piston assembly having an inner piston that is slidably mounted within an outer piston and coupled to an actuator. The actuator is further coupled to a fluid source, and a volume of fluid is selectively channeled into and out of the actuator to move the inner piston to selected positions corresponding to desired compression ratios. At top dead center, a top face of the outer piston maintains a substantially constant distance from an engine head assembly to minimize squish area variations.

Abstract: Two motors are arranged on opposing sides of a common shaft, drive plates of the pump/motors being rigidly coupled to each other, for example by being in hard contact with opposing sides of the shaft. By providing hard contact between the pump/motor drive plates and a common shaft, the drive plates and shaft act as a substantially solid element under compression, thereby substantially canceling axial loads generated by the pump/motors directly through the shaft. Residual axial loads are handled via bearings positioned on the shaft adjacent the drive plates in such a manner that the drive plates are in light contact only with the bearings. As a result, friction experienced by the bearings is substantially reduced as compared to conventional systems, thereby improving the efficiency of the system.

Abstract: A free-piston engine includes at least one dual piston assembly, each of which has a pair of axially opposed combustion cylinders and free-floating combustion pistons respectively mounted in the combustion cylinders for reciprocating linear motion responsive to successive combustions. A pumping piston extends from and is fixed to each of the combustion pistons and reciprocates within a hydraulic cylinder located between paired combustion cylinders. The paired combustion cylinders are rigidly connected by a cage for reciprocating movement in tandem.

Abstract: A method of operating an internal combustion engine wherein intake ambient air is boosted to a higher pressure by passage through at least one compressor and then introduced into the internal combustion engine. Fuel is also introduced into the internal combustion engine for providing combustion in admixture with the air charge at a combustion temperature approximating a target value. Various engine operating parameters, inclusive of torque demand, e.g., accelerator pedal depression, are sensed and the boosted pressure is changed in a manner proportional to a change in the sensed torque demand so as to maintain the combustion temperature at approximately the target value, i.e., below 2100° K.

Abstract: A hydraulic accumulator is equipped with a novel shut-off valve. The shut off-valve includes a valve body having a cylindrical hollow with a valve seat surrounding one end. The main piston including a piston head has a central opening and is slidably mounted within the cylindrical hollow of the valve body. A poppet valve has a valve head which mates with the valve seat and a valve stem which extends through the central opening of the piston to guide axial movement of the poppet valve relative to the piston. A spring is mounted between the valve head and the main piston head for urging the valve head away from the piston head. A control valve moves the piston relative to the valve body between open and closed positions responsive to signals from a computer which signals valve closing upon determination that flow rate through the valve exceeds a maximum period.

Abstract: A free-piston engine includes at least one dual piston assembly, each of which has a pair of axially opposed combustion cylinders and free-floating combustion pistons respectively mounted in the combustion cylinders for reciprocating linear motion responsive to successive combustions. A pumping piston extends from and is fixed to each of the combustion pistons and reciprocates within a hydraulic cylinder located between paired combustion cylinders. The paired combustion cylinders are rigidly connected by a cage for reciprocating movement in tandem.

Abstract: A free-piston engine includes at least one dual piston assembly, each of which has a pair of axially opposed combustion cylinders and free-floating combustion pistons respectively mounted in the combustion cylinders for reciprocating linear motion responsive to successive combustions. A pumping piston extends from and is fixed to each of the combustion pistons and reciprocates within a hydraulic cylinder located between paired combustion cylinders. The paired combustion cylinders are rigidly connected by a cage for reciprocating movement in tandem.

Abstract: A hydraulic accumulator includes a rigid tank containing a flexible but non-elastic bladder formed of a metal foil and separating the interior of the tank into a gas space and a liquid space. The gas and liquid spaces respectively communicate with exterior sources of gas and liquid through fixtures provided on the accumulator tank. One of the fixtures is provided with an anti-extrusion valve to prevent the bladder from being forced out through the fixture. In one preferred embodiment the bladder is a bellows. In another preferred embodiment the accumulator tank is provided with a vent in communication with the liquid space within the tank to allow for venting of any gas separating from the liquid and accumulating within the liquid space.

Abstract: An engine has a plurality of combustion cylinders with a first piston reciprocably mounted in each of the combustion cylinders in the conventional manner. The engine head has, in communication with each of the combustion cylinders, a cylindrical recess containing a reciprocably mounted second piston. On the side of the second piston opposite the combustion chamber is a control chamber with inlets and outlets for controlling movement of the second piston. The second piston is used to increase the compression ratio without appreciably reducing the expansion ratio. Alternatively, the second piston may be used as a pump to pump fluid from the control chamber. In yet another alternative method of operation, the second piston can be driven outward within the cylindrical recess to an extent which varies in accordance with power demand, thereby varying the compression ratio in accordance with the power demand.

Abstract: A hydraulic accumulator is equipped with a novel shut-off valve. The shut off-valve includes a valve body having a cylindrical hollow with a valve seat surrounding one end. The main piston including a piston head has a central opening and is slidably mounted within the cylindrical hollow of the valve body. A poppet valve has a valve head which mates with the valve seat and a valve stem which extends through the central opening of the piston to guide axial movement of the poppet valve relative to the piston. A spring is mounted between the valve head and the main piston head for urging the valve head away from the piston head. A control valve moves the piston relative to the valve body between open and closed positions responsive to signals from a computer which signals valve closing upon determination that flow rate through the valve exceeds a maximum period.

Abstract: An engine has a plurality of combustion cylinders with a first piston reciprocably mounted in each of the combustion cylinders in the conventional manner. The engine head has, in communication with each of the combustion cylinders, a cylindrical recess containing a reciprocably mounted second piston. On the side of the second piston opposite the combustion chamber is a control chamber with inlets and outlets for controlling movement of the second piston. The second piston is used to increase the compression ratio without appreciably reducing the expansion ratio. Alternatively, the second piston may be used as a pump to pump fluid from the control chamber. In yet another alternative method of operation, the second piston can be driven outward within the cylindrical recess to an extent which varies in accordance with power demand, thereby varying the compression ratio in accordance with the power demand.

Abstract: A free-piston engine includes at least one dual piston assembly, each of which has a pair of axially opposed combustion cylinders and free-floating combustion pistons respectively mounted in the combustion cylinders for reciprocating linear motion responsive to successive combustions. A pumping piston extends from and is fixed to each of the combustion pistons and reciprocates within a hydraulic cylinder located between paired combustion cylinders. The paired combustion cylinders are rigidly connected by a cage for reciprocating movement in tandem.

Abstract: A diesel-cycle engine with a unique exhaust gas recirculation system includes a plurality of cylinders with fuel feed for each of the cylinders and an intake manifold for distributing intake air to each of the cylinders for combustion of the fuel charges therein with generation of exhaust gas. The exhaust gas is discharged to ambient atmosphere through an exhaust line with a gas turbine therein. The gas turbine drives an intake compressor which serves to compress the intake air. An engine controller controls a valve regulating the amount of exhaust gas recirculation responsive to sensed concentration of an exhaust gas component. In another embodiment, an engine controller controls a valve regulating the amount of exhaust gas recirculation, responsive to sensed demand for torque and control of fuel injection quantity is responsive to sensed concentration of an exhaust gas component.

Abstract: An air bottoming powertrain, suitable for use in automobiles includes an internal combustion engine, a compressor which receives gaseous working fluid and compresses it to an elevated pressure, a cooler for operating the compressor isothermally, an expander for deriving work from the compressed gas and a heat exchanger located in the compressed gas line for indirect heat exchange between the compressed working fluid and exhaust gas from the internal combustion engine. The expander may have a cylindrical barrel with a plurality of cylinders arranged in the circle and open at one end face of the cylinder barrel, which end face is sealed closed by a valve plate. The cylinder barrel and valve plate allow relative rotation therebetween to drive an output shaft, driven by compressed gas from the compressor. An alternative expander is a Scotch Yoke piston motor which includes plural paired and axially aligned cylinders on opposing sides of an output shaft.

Abstract: An exhaust gas recirculation system for an internal combustion engine includes an exhaust manifold and at least one exhaust flow control valve located between the engine and the exhaust manifold. The exhaust flow control valve diverts a portion of the exhaust gas from each cycle of one cylinder and feeds that diverted portion to another of the cylinders through an exhaust gas recirculation passage, bypassing the exhaust manifold, whereby an exhaust stroke of a piston within the one cylinder serves to pump exhaust gas through the exhaust flow control valve in another cylinder.

Abstract: An air bottoming powertrain, suitable for use in automobiles includes an internal combustion engine, a compressor which receives gaseous working fluid and compresses it to an elevated pressure, a cooler for operating the compressor isothermally, an expander for deriving work from the compressed gas and a heat exchanger located in the compressed gas line for indirect heat exchange between the compressed working fluid and exhaust gas from the internal combustion engine. The expander may have a cylindrical barrel with a plurality of cylinders arranged in the circle and open at one end face of the cylinder barrel, which end face is sealed closed by a valve plate. The cylinder barrel and valve plate allow relative rotation therebetween to drive an output shaft, driven by compressed gas from the compressor. An alternative expander is a Scotch Yoke piston motor which includes plural paired and axially aligned cylinders on opposing sides of an output shaft.

Abstract: A diesel-cycle engine with a unique exhaust gas recirculation system includes a plurality of cylinders with fuel feed for each of the cylinders and an intake manifold for distributing intake air to each of the cylinders for combustion of the fuel charges therein with generation of exhaust gas. The exhaust gas is discharged to ambient atmosphere through an exhaust line with a gas turbine therein. The gas turbine drives an intake compressor which serves to compress the intake air. An engine controller controls a valve regulating the amount of exhaust gas recirculation responsive to sensed concentration of an exhaust gas component. In another embodiment, an engine controller controls a valve regulating the amount of exhaust gas recirculation, responsive to sensed demand for torque and control of fuel injection quantity is responsive to sensed concentration of an exhaust gas component.

Abstract: An air bottoming powertrain, suitable for use in automobiles includes an internal combustion engine, a compressor which receives gaseous working fluid and compresses it to an elevated pressure, a cooler for operating the compressor isothermally, an expander for deriving work from the compressed gas and a heat exchanger located in the compressed gas line for indirect heat exchange between the compressed working fluid and exhaust gas from the internal combustion engine. The expander may have a cylindrical barrel with a plurality of cylinders arranged in the circle and open at one end face of the cylinder barrel, which end face is sealed closed by a valve plate. The cylinder barrel and valve plate allow relative rotation therebetween to drive an output shaft, driven by compressed gas from the compressor. An alternative expander is a Scotch Yoke piston motor which includes plural paired and axially aligned cylinders on opposing sides of an output shaft.

Abstract: A diesel-cycle engine with a unique exhaust gas recirculation system includes a plurality of cylinders with fuel feed for each of the cylinders and an intake manifold for distributing intake air to each of the cylinders for combustion of the fuel charges therein with generation of exhaust gas. The exhaust gas is discharged to ambient atmosphere through an exhaust line with a gas turbine therein. The gas turbine drives an intake compressor which serves to compress the intake air. An engine controller controls a valve regulating the amount of exhaust gas recirculation responsive to sensed concentration of an exhaust gas component. In another embodiment, an engine controller controls a valve regulating the amount of exhaust gas recirculation, responsive to sensed demand for torque and control of fuel injection quantity is responsive to sensed concentration of an exhaust gas component.