Abstract: One implementation of an air boost system for an engine includes a boost device and an accumulator adapted to store pressurized fluid and selectively provide pressurized fluid to the boost device. A pump may deliver fluid under pressure to one or both of the accumulator and the boost device in at least some operating conditions. A first control valve may be disposed between the pump and the accumulator to control fluid flow to the accumulator, and a bypass may be provided between the pump and the first control valve. The bypass may, in at least some operating conditions, permit at least some of the pressurized fluid from the pump to bypass the accumulator and be delivered to the boost device. In one form, the accumulator is carried by the boost device in a compact unit.

Abstract: A regulated two-stage turbocharger system is described, including high-pressure and low-pressure turbocharger units. The low-pressure turbocharger unit includes a twin volute turbine portion. The turbocharger system includes a valve system having valve members that are independently controllable so as to selectively control an exhaust gas flow into the twin volutes of the turbine portion of the low-pressure turbocharger unit. By-pass valve systems are also provided for the twin volute turbine portion of the low-pressure turbocharger unit and the compressor portion of the high-pressure turbocharger unit.

Abstract: The present invention provides a two-stage turbocharger unit having a valve that will help to create a smooth transition of exhaust gas energy from the high-pressure turbine (HP) turbine to the low-pressure (LP) turbine. The LP and HP turbines are positioned such that the valve can be in one position to force all of the exhaust gas to flow through the HP turbine and when in another position to force all of the exhaust gas through the LP turbine. When the valve is placed in an intermediary position, the exhaust gas can be variably directed to flow through both turbines, with the percentage of exhaust gas flowing through each turbine being dependent on the position of the valve.

Abstract: A regulated two-stage turbocharger system is described. The turbocharger system includes high-pressure and low-pressure turbocharger units in communication with one another. The turbocharger system includes a valve system having valve members that are independently controllable so as to selectively control the gas flow into the turbine portions of the high-pressure turbocharger and the low-pressure turbocharger units. The valve members are asymmetric, e.g., they possess differing areas (e.g., perimeters, diameters and/or the like) with respect to one another.

Abstract: A regulated two-stage turbocharger system is described. The turbocharger system includes high-pressure and low-pressure turbocharger units in communication with one another. The turbocharger system includes a valve system having valve members that are independently controllable so as to selectively control the gas flow into the turbine portions of the high-pressure turbocharger and the low-pressure turbocharger units. The valve members are asymmetric, e.g., they possess differing areas (e.g., perimeters, diameters and/or the like) with respect to one another.