Shrouded turbine blades with locally increased contact faces
AssigneePratt & Wiley Canada Corp.
InventorsRené Paquet, Nicolas Grivas, Richard Brandt
Life of this patent
Estimating the term…
Abstract
A one-piece blade for a turbine section of a gas turbine engine, the blade comprising a root, an airfoil and a shroud. The shroud extends generally perpendicularly from a tip of the airfoil and is defined by a pair of opposed bearing faces and a pair of opposed non-bearing faces. The bearing faces each have a contact portion adapted to contact a shroud of an adjacent blade. The shroud has a substantially constant nominal thickness and the bearing faces have a substantially constant face thickness across the contact portion, the face thickness being greater than the nominal thickness. The transition between the face thickness and the nominal thickness is substantially discontinuous.
Claims17
A one-piece blade for a turbine section of a gas turbine engine, the blade comprising a root, an airfoil and a shroud, wherein the shroud extends generally perpendicularly from a tip of the airfoil and is defined by a pair of opposed bearing faces integrally formed with said shroud and a pair of opposed non-bearing fares, the bearing faces each having a contact portion adapted to contact a shroud of an adjacent blade, the shroud having a portion extending between the contact portion of the bearing faces and having a substantially constant nominal thickness, the bearing faces having a substantially constant face thickness across the contact portion greater than the nominal thickness, the transition between the face thickness of the bearing faces and the nominal thickness of said portion being substantially discontinuous.
A blade for a turbine section of a gas turbine engine, the blade comprising:
- an airfoil portion extending from a root portion to a tip portion;
- and
- a shroud pardon extending laterally from the airfoil portion, the shroud portion having a body having a substantially constant thickness and a pair of opposed bearing faces integrally formed with said body each having contact portions adapted to matingly contact a bearing face contact portion of a shroud portion of an adjacent turbine blade, wherein the body has a generally planar portion extending between the opposed bearing faces and having the constant thickness, at least one of the opposed bearing faces having a discontinuous increase in thickness relative to the constant thickness immediately adjacent the contact portion of the at least one of the opposed bearing faces to thereby provide substantially all of the contact portion with an increased surface area associated with said increased thickness, and wherein said increased surface area is adapted to lower contact stresses arising from contact with at least one mating bearing face of said adjacent turbine blades.
A method of reducing face contact stress in a shroud contact face of a shrouded turbine blade, the method comprising the steps of:
- determining a desired shroud design for a given turbine blade design, the shroud design including a nominal thickness;
- determining a desired face contact stress for at least one shroud contact face of the shroud, the at least one shroud contact face having a contact portion length;
- and
- providing a local increase in the shroud nominal thickness to thereby increase the area of the at least one shroud contact face along said contact portion length, wherein the increase in area corresponds to the desired face contract stress, and wherein the local increase is limited to a region immediately adjacent the at least one shroud contact face.
Dependencies are inferred from the claim text.