Abstract A rotor stage of an axial-flow turbine includes a bladed wheel made up of circumferentially abutting radially extending elements, each of which has a blade at its outer end and a sector of the wheel hub at its inner end. The wheel hub sectors are mounted between abutments on a shaft, which may be undercut to provide a dovetail connection between the hub sectors and the abutments to hold the wheel together. The wheel sectors may be united by brazing or welding, in which case the abutments are not necessarily undercut. An interlock may be provided between adjacent wheel elements by a dovetail connection between the flanks of the elements or by separate keys engaging in slots in the flanks of the elements. The wheel portion of the rotor stage is made impervious to leakage of fluid through it by webs extending from the wheel elements into contact with each other or by annular disks covering the radially central portion of the wheel elements.
A turbomachine rotor stage comprising, in combination, a shaft, first and second abutment means on the shaft defining between them a circumferential dovetail slot, and a wheel including a flaring hub held within the dovetail slot, the wheel comprising a ring of laterally abutting elements extending radially from the shaft, each element including a sector of the hub, a connecting portion extending outwardly from the hub sector, a platform at the outer end of the connecting portion, and a blade extending from the platform, the elements abutting and being bonded together at the hub portion to provide a unitary wheel hub and being unbonded radially outward from the hub portion, and abutting at the platforms, the stage including means to block flow between the connecting portions of adjacent elements.
Claim 2
Dependent Claim
129 words
A turbomachine rotor stage comprising, in combination, a shaft, first and second abutment means on the shaft defining between them a circumferential dovetail slot, and a wheel including a flaring hub held within the dovetail slot, the wheel comprising a ring of laterally abutting elements extending radially from the shaft, each element including a sector of the hub, a connecting portion extending outwardly from the hub sector, a platform at the outer end of the connecting portion, and a blade extending from the platform, the elements abutting and being bonded together at the hub portion to provide a unitary wheel hub and being unbonded radially outward from the hub portion, and abutting at the platforms, the stage including means to block flow between the connecting portions of adjacent elements.
Claim 3
Dependent Claim
25 words
A stage as defined in claim 1 in which the connecting portions include laterally extending flanges which abut to block flow between the connecting portions.
Claim 4
Dependent Claim
26 words
A stage as defined in claim 1 including an annular seal ring extending from the hub to the platforms to block flow between the connecting portions.