Abstract: A turbine assembly comprising a housing comprising first and second volutes which define a respective first and second flow passage. A circumferential outlet portion of each volute is defined by first and second tongues. The housing further comprises a first aperture in which a vane assembly is received. The vane assembly comprises a plurality of vanes circumferentially distributed about a turbine wheel-receiving bore, each vane comprising a leading edge and a trailing edge. Each vane has a fixed orientation. The vanes comprise a first vane and a second vane. The first vane having its leading edge disposed in closest proximity to a tip of the first tongue. The second vane having its leading edge disposed in closest proximity to a tip of the second tongue. The leading edge of each vane at least partly overlaps the tip of the proximate tongue circumferentially.

Abstract: A pin member is proposed for a turbo-machine having a shroud arranged to rotate within a turbine housing. The pin member is configured to limit this rotation. It is a one-piece element comprising a cylindrical body and a limit surface for opposing motion of the shroud.

Abstract: There is disclosed a bearing housing for a turbocharger. The bearing housing comprises a body and a mounting flange. The body is configured to receive one or more bearings. The one or more bearings are configured to support rotation of a shaft about an axis. The mounting flange extends around the body. The mounting flange comprises a plurality of bores, a first face and a plurality of cavities. The plurality of bores configured to receive a fastener therethrough. The first face is configured to engage a corresponding mounting flange of a turbine housing. The plurality of cavities are in communication with the plurality of bores. The plurality of cavities are axially recessed relative to the first face.

Abstract: A turbine for a turbo-machine is proposed in which, at a gas inlet for a turbine wheel, vanes extend from a nozzle ring though slots in a shroud. The nozzle ring and shroud are relatively rotatable about a rotational axis of the turbine by at least 0.1 degrees. In use, the nozzle ring and shroud are relatively rotated to bring one side of the vane into close contact with one surface of the slot, to inhibit leakage of gas between the vane and the slot surface. For this purpose the respective surfaces of the nozzle and slot can be configured to closely conform to each other. If there is differential thermal expansion of the shroud and nozzle ring, the nozzle ring and shroud can relatively rotate, to withdraw the vane from the edge of the slot to relieve the pressure between them.

Abstract: A turbine wheel consists of a first shroud component and a second bladed disc component. The shroud component comprises a shroud structure, a hub structure and a spoke formed integrally therewith and extending between the shroud structure and the hub structure. The bladed disc component comprises a hub member having inner and outer rims, turbine blades disposed on the outer rim, and at least one receiving zone for receiving the spoke, said at least one receiving zone extending radially between the inner and outer rims. The shroud component and the bladed disc component are connected and thus provide the turbine wheel with a shrouded portion. A shrouded turbine wheel can therefore be conveniently assembled starting from at least two components. Further, these components have simplified geometries for easy manufacture, for example using a casting technique, while the overall mechanical performance of the turbine is preserved or improved.

Abstract: A turbine comprising: a turbine housing, a wastegate passage connecting the turbine inlet and the turbine outlet; and a wastegate valve comprising a movable valve member. The wastegate valve has an open state in which a first gas may pass between a turbine inlet a turbine outlet via the wastegate passage and a closed state in which the valve member substantially prevents said first gas from passing between the turbine inlet and the turbine outlet. The valve member is mounted to an actuation member that passes through a bore of the turbine housing. The actuation member is movable to move the wastegate valve between the open and closed states. The turbine comprises a fluid conduit configured to deliver a second gas to the bore to form a fluidic seal between the bore and the actuation member to substantially prevent the passage of said first gas along the bore.

Abstract: A valve system comprising a valve chamber at a junction of an inlet port, an outlet port and a bypass port, the inlet port configured for fluid communication with exhaust gas, 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; a rotary valve comprising a valve rotor which rotates about a valve axis within the valve chamber between a first position to permit gas flow through the bypass port and a second position to block gas flow. At least one of the valve rotor and the valve chamber comprises a protrusion and the other comprises a recess, wherein, in the first position, the protrusion and recess are spaced from one another, and, in the second position the recess receives the protrusion such that gas flow between the protrusion and recess is substantially prevented.

Abstract: A rotary turbine bypass valve comprises a valve chamber and a valve rotor. The chamber is positioned at a junction of an inlet port, an outlet port and a bypass port. The inlet port is configured to receive exhaust gas, the outlet port is configured to fluidly communicate with a turbine inlet, and the bypass port is configured to fluidly communicate with an exhaust aftertreatment device. The rotor comprises a first and second recess, the first recess defining a primary flow passage, the second recess defining a secondary flow passage. The rotor is rotatable between a first position in which the rotor substantially blocks exhaust gas flow through the bypass port and a second position in which the rotor permits such. The secondary flow passage is configured to selectively permit fluid communication between the inlet port and the bypass port when the primary flow passage is partially blocked.

Abstract: A turbine comprises a turbine wheel for rotation within a turbine housing, the turbine housing including at least one volute arranged to deliver a fluid to the turbine wheel via the turbine nozzle. A method for determining a width of a turbine nozzle for the turbine, comprises selecting from a relationship between a turbine stage efficiency and an effective nozzle area, at least one target effective nozzle area. As used here, the effective nozzle area is dependent on both the width of the turbine nozzle and a whirl angle induced by the at least one volute. The method further comprises determining, in dependence on the whirl angle, the width of the turbine nozzle as a width that will achieve the at least one target effective nozzle area.

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 seal assembly for use in a turbomachine, the seal assembly comprising an oil seal plate; a rotatable component which defines a central axis and is received in a central aperture of the oil seal plate; and an annular seal which comprises a base and a sealing portion, the base being held by the rotatable component; wherein the sealing portion is configured to form a seal with the oil seal plate when the rotatable component and annular seal are rotating below a predetermined rotational speed; and wherein the sealing portion is configured to move radially outwards with respect to the central axis such that the sealing portion loses contact with the oil seal plate when the rotatable component and annular seal are rotating above the predetermined rotational speed.

Abstract: There is disclosed a bearing housing for a turbocharger. The bearing housing comprises a body and a mounting flange. The body is configured to receive one or more bearings. The one or more bearings are configured to support rotation of a shaft about an axis. The mounting flange extends around the body. The mounting flange comprises a plurality of bores, a first face and a plurality of cavities. The plurality of bores configured to receive a fastener therethrough. The first face is configured to engage a corresponding mounting flange of a turbine housing. The plurality of cavities are in communication with the plurality of bores. The plurality of cavities are axially recessed relative to the first face.

Abstract: A turbine for a turbo-machine is proposed in which, at a gas inlet, vanes, extending from a nozzle ring though slots in a shroud, are shaped on one side to as to substantially conform to the profile of the surface of the slot, whereby a close connection can be formed between the vane and the slot to inhibit leakage of gas between the vane and the slot surface.

Abstract: A turbine comprises a turbine housing defining a turbine inlet upstream of a turbine wheel and a turbine outlet downstream of the turbine wheel; and a wastegate valve assembly comprising at least one movable valve member mounted on a movable support member within a wastegate chamber which communicates with the turbine inlet upstream of the turbine, and has one or more chamber outlets which communicate with an outlet of the turbine. The valve member is permitted to articulate slightly about the support member, with the amount of articulation in respective directions being limited by collisions between a respective limit point on a limit area on a rear surface of a sealing portion of the valve member and a respective limit point on limit area on a front surface of the support member.

Abstract: A turbine for a turbo-machine is proposed in which, at a gas inlet for a turbine wheel, vanes extend from a nozzle ring though slots in a shroud. The vanes are formed with a leading portion which is arranged to contact a leading portion of a corresponding slot, and a trailing portion which is shaped, when the leading portion of the vane and slot are together, to be spaced from a corresponding trailing portion of the slot with a substantially constant spacing at room temperature. The contact may be a point contact, e.g. close to the leading edge of the vane. Alternatively, the vane may include a leading surface portion which conforms closely with the shape of a corresponding leading surface portion of one of the slots.

Abstract: There is disclosed a bush comprising an internal surface and an external surface. The internal surface defines a bore and is configured to support movement of a body received in the bore. The external surface defines an outer radius. The external surface comprises one or more recesses.

Abstract: A turbine for a turbo-machine is proposed in which, at a gas inlet for a turbine wheel, vanes extend from a nozzle ring though slots in a shroud. The nozzle ring and shroud are relatively rotatable about a rotational axis of the turbine by at least 0.1 degrees. In use, the nozzle ring and shroud are relatively rotated to bring one side of the vane into close contact with one surface of the slot, to inhibit leakage of gas between the vane and the slot surface. For this purpose the respective surfaces of the nozzle and slot can be configured to closely conform to each other. If there is differential thermal expansion of the shroud and nozzle ring, the nozzle ring and shroud can relatively rotate, to withdraw the vane from the edge of the slot to relieve the pressure between them.

Abstract: A turbine bypass valve comprising: a casing defining first and second casing ports; and a valve cartridge mounted to the casing; wherein the valve cartridge comprises: first and second valve ports; and a valve member, the valve member being movable between a first position in which there is a flow path between the first and second valve ports, and a second position in which the valve member substantially blocks said flow path between the first and second valve ports; and wherein the valve cartridge is mounted to the casing such that the first valve port is aligned with the first casing port, and the second valve port is aligned with the second casing port.

Abstract: There is provided a turbine comprising: a turbine housing; a turbine wheel; an inlet upstream of the turbine wheel, the inlet defining a first inlet portion and a second inlet portion; an outlet downstream of the turbine wheel, the outlet defining a first outlet portion and a second outlet portion; and a wastegate arrangement configured to selectively vent exhaust gas from the first inlet portion to the first outlet portion via a first bypass passage, and further configured to selectively vent exhaust gas from the second inlet portion to the second outlet portion via a second bypass passage; wherein the first outlet portion and the second outlet portion are separated by a baffle of the turbine housing.