Turbine airfoil fabricated from tapered extrusions
AssigneeSiemens Energy, Inc.
InventorJohn J. Marra
Life of this patent
Estimating the term…
Abstract
An airfoil (30) and fabrication process for turbine blades with cooling channels (26). Tapered tubes (32A-32D) are bonded together in a parallel sequence, forming a leading edge (21), a trailing edge (22), and pressure and suction side walls (23, 24) connected by internal ribs (25). The tapered tubes may be extruded without camber to simplify the extrusion process, then bonded along matching surfaces (34), forming a non-cambered airfoil (28), which may be cambered in a hot forming process and cut (48) to length. The tubes may have tapered walls that are thinner at the blade tip (T1) than at the base (T2), reducing mass. A cap (50) may be attached to the blade tip. A mounting lug (58) may be forged (60) on the airfoil base and then machined, completing the blade for mounting in a turbine rotor disk.
Claims20
A turbine airfoil comprising:
- a plurality of tapered tubes bonded together in a parallel sequence such that an outer surface of the tubes is an outer surface of an airfoil, the outer surface of a first of the tubes is a leading edge, and the outer surface of a last of the tubes is a trailing edge;
- wherein walls of the tubes form pressure and suction side walls of the airfoil and internal ribs there between;
- and
- wherein the tapered tubes comprise outer dimensions that taper from relatively smaller at a tip end of the airfoil to relatively larger at a base end of the airfoil, and the walls of the tubes taper from thinner at the tip end of the airfoil to thicker at the base end of the airfoil.
A method of fabricating a turbine airfoil, comprising:
- forming a plurality of tapered tubes, each tube comprising a smaller end and a larger end, and comprising walls that are thinner at the smaller end than at the larger end;
- and
- bonding the tapered tubes to each other in a parallel sequence such that an outer surface of the tapered tubes is an outer surface of an airfoil comprising a leading edge, a trailing edge, side walls connected by internal ribs, a tip end of the airfoil, and a base end of the airfoil that is larger than the tip end.
A method of fabricating a turbine airfoil, comprising:
- extruding a series of tapered tubes with respectively matched bonding surfaces;
- bonding the tubes to each other in a parallel sequence to form a non-cambered airfoil preform;
- hot-forming a cambered airfoil from the preform;
- cutting the airfoil to a particular length;
- mounting a tip cap on the airfoil;
- upset forging a mounting lug on a base end of the cambered airfoil;
- and
- machining the mounting lug to a final geometry.
A method of fabricating a turbine airfoil, comprising:
- forming a plurality of tapered tubes, each tube comprising a smaller end and a larger end, and comprising walls that are thinner at the smaller end than at the larger end;
- bonding the tapered tubes to each other in a parallel sequence that forms an airfoil comprising a leading edge, a trailing edge, side walls connected by internal ribs, a tip end of the airfoil, and a base end of the airfoil that is larger than the tip end;
- bonding a tip cap over the tip end of the airfoil;
- and
- forming a mounting lug on the base end of the airfoil,
- wherein either the step of bonding of the tip cap or the step of forming of a mounting lug may be done prior to the other of these two steps.
A method of fabricating a turbine airfoil, comprising:
- forming a plurality of tapered tubes, each tube comprising a smaller end and a larger end, and comprising walls that are thinner at the smaller end than at the larger end;
- bonding the tapered tubes to each other in a parallel sequence that forms an airfoil comprising a leading edge, a trailing edge, side walls connected by internal ribs, a tip end of the airfoil, and a base end of the airfoil that is larger than the tip end;
- forming the tubes without curvature for airfoil camber;
- bonding the tubes to each other to form a flat preform of a non-cambered airfoil;
- and
- hot-forming the preform into a cambered airfoil.
A method of fabricating a turbine airfoil, comprising:
- forming a plurality of tapered tubes, each tube comprising a smaller end and a larger end, and comprising walls that are thinner at the smaller end than at the larger end;
- bonding the tapered tubes to each other in a parallel sequence that forms an airfoil comprising a leading edge, a trailing edge, side walls connected by internal ribs, a tip end of the airfoil, and a base end of the airfoil that is larger than the tip end;
- and
- forming a mounting lug by upset forging at least one pair of opposed laterally extending ridges on the airfoil base.
A turbine airfoil comprising:
- a plurality of tapered tubes bonded together in a parallel sequence forming an airfoil, a first of the tubes forming a leading edge, a last of the tubes forming a trailing edge;
- a tip cap bonded over a tip end of the airfoil;
- and
- a mounting lug formed on a base end of the airfoil
- wherein walls of the tubes form pressure and suction side walls of the airfoil and internal ribs there between;
- wherein the tapered tubes comprise outer dimensions that taper from relatively smaller at the tip end of the airfoil to relatively larger at the base end of the airfoil, and the walls of the tubes taper from thinner at the tip end of the airfoil to thicker at the base end of the airfoil.
Dependencies are inferred from the claim text.