Abstract: A turbocharger (1) with an axial flow turbine stage (2) includes a compressor stage (4) using active casing treatment (50) for choke flow improvement. With switchable slots (52, 54), one of the slots (52) may be between the compressor's full and splitter blades (27, 23) and one of the slots (54) can be located downstream of the compressor's splitter blades (23) to maximize choke flow capacity. In turbochargers with a wastegate assembly, a pneumatic actuator (32) may control both a wastegate control valve (30) and an active casing treatment slot selection valve (56).

Abstract: A turbocharger (1) including a twin scroll turbine and a valve assembly (40, 140) disposed in the exhaust gas inlet (24, 124) that is configured to control the flow exhaust gas through the turbine. The valve assembly (40, 140) includes two rotary valves (60, 160, 80, 180) actuated by a common valve shaft (44, 144). One of the valves (60, 180) may control exhaust gas flow to a volute or between volutes, and the other (80, 160) may control wastegate exhaust gas flow. The valve shaft (44, 144) is driven by an actuator to rotate about the valve shaft rotational axis (46, 146) such that the first valve (60, 160) and the second valve (80, 180) can each be selectively moved between a closed position and an open position, and the time sequence order of opening of the first valve (60, 160) and the second valve (80, 180) is selectable.

Abstract: A turbocharger (1) including a twin scroll turbine and a valve assembly (40, 140) disposed in the exhaust gas inlet (24, 124) that is configured to control the flow exhaust gas through the turbine. The valve assembly (40, 140) includes two rotary valves (60, 160, 80, 180) actuated by a common valve shaft (44, 144). One of the valves (60, 180) may control exhaust gas flow to a volute or between volutes, and the other (80, 160) may control wastegate exhaust gas flow. The valve shaft (44, 144) is driven by an actuator to rotate about the valve shaft rotational axis (46, 146) such that the first valve (60, 160) and the second valve (80, 180) can each be selectively moved between a closed position and an open position, and the time sequence order of opening of the first valve (60, 160) and the second valve (80, 180) is selectable.