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 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 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 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.