Abstract: A rotary turbine bypass valve comprises a valve chamber positioned at a junction of an inlet port, an outlet port and a bypass port, the inlet port configured for fluid communication with a flow of exhaust gas from an engine, the outlet port configured for fluid communication with an inlet of a turbine, and the bypass port configured for fluid communication with an exhaust aftertreatment device; and a valve rotor supported for rotation, about a valve axis, within the valve chamber. The valve rotor is rotatable about the valve axis between a first position in which the valve rotor permits gas flow through the bypass port and a second position in which the valve rotor blocks gas flow through the bypass port.

Abstract: A turbine housing defining a pair of volutes with respective outlets divided by a divider wall, includes a diffuser space in the gas flow path between the volutes and the turbine wheel. The diffuser space has an upstream portion having a smaller axial extent than a downstream portion of the diffuser space. The widening of the diffuser space tends to direct exhaust gas entering the diffusion space from at least one side of the divider wall towards the corresponding axial end of the diffuser space. Thus reduces the tendency of this gas to interrupt the flow into the diffuser space of exhaust gas from the other inlet volute.

Abstract: A mixed-flow turbine wheel is proposed which, compared to existing mixed-flow turbine wheels, has reduced mass and moment of inertia because radially-outer portions of existing mixed-flow turbine wheels are omitted. In a first possibility, the omitted material may be scalloping of the back face of the turbine wheel at a radial position outward of a base line which is a circle on the back surface of the wheel which indicates the minimum radius of the back surface. In a second possibility, part of the webbing of each blade is omitted to one side of the blade. Thus, viewing the turbine wheel in the axial direction, the area of the webbing outside the baseline and to one side of a radial line through the inducer tip, may be at least 20% less than that on the other side.

Abstract: A rotary turbine bypass valve comprises a valve chamber positioned at a junction of an inlet port, an outlet port and a bypass port, the inlet port configured for fluid communication with a flow of exhaust gas from an engine, the outlet port configured for fluid communication with an inlet of a turbine, and the bypass port configured for fluid communication with an exhaust aftertreatment device; and a valve rotor supported for rotation, about a valve axis, within the valve chamber. The valve rotor is rotatable about the valve axis between a first position in which the valve rotor permits gas flow through the bypass port and a second position in which the valve rotor blocks gas flow through the bypass port.

Abstract: A turbine housing defining a pair of volutes with respective outlets divided by a divider wall, includes a diffuser space in the gas flow path between the volutes and the turbine wheel. The diffuser space has an upstream portion having a smaller axial extent than a downstream portion of the diffuser space. The widening of the diffuser space tends to direct exhaust gas entering the diffusion space from at least one side of the divider wall towards the corresponding axial end of the diffuser space. Thus reduces the tendency of this gas to interrupt the flow into the diffuser space of exhaust gas from the other inlet volute.

Abstract: A mixed-flow turbine wheel is proposed which, compared to existing mixed-flow turbine wheels, has reduced mass and moment of inertia because radially-outer portions of existing mixed-flow turbine wheels are omitted. In a first possibility, the omitted material may be scalloping of the back face of the turbine wheel at a radial position outward of a base line which is a circle on the back surface of the wheel which indicates the minimum radius of the back surface. In a second possibility, part of the webbing of each blade is omitted to one side of the blade. Thus, viewing the turbine wheel in the axial direction, the area of the webbing outside the baseline and to one side of a radial line through the inducer tip, may be at least 20% less than that on the other side.