Rotor assembly with blade sealing tab
The gas turbine engine rotor assembly includes a rotor disc with a plurality of sealing tabs projecting radially out from a peripheral surface of the rotor disc in the rear end portion thereof. A said sealing tab is disposed at a tip portion of a fixing member of the disc, formed between pairs of blade root slots, adjacent a trailing edge of the rotor disc. The sealing tabs help to reduce the leakage of secondary air out the back of a blade pocket defined between adjacent blades mounted on the rotor disc.
1. A rotor assembly for a gas turbine engine, comprising:
a plurality of blades each having a blade root, an airfoil, and a platform disposed between the blade root and the airfoil, the platform extending laterally to a corresponding platform of an adjacent one of the plurality of blades,
a rotor disc having a front face, a rear face and a peripheral surface, a plurality of slots circumferentially spaced about and formed in the peripheral surface, and a plurality of fixing members extending from the front face to the rear face and circumferentially disposed between adjacent slots, the fixing members comprising lobes configured to matingly receive the blade roots, the peripheral surface of the disc forming a radially outer tip of the fixing members, the disc connected to the blades at the peripheral surface;
a sealing tab disposed on one or more of the fixing members, the sealing tab projecting radially outward relative to the radially outer tip of the fixing members, the sealing tab axially disposed at a downstream end of the radially outer tip of the fixing members proximate the rear face of the rotor disc.
2. The rotor assembly as defined in claim 1 , wherein the sealing tab includes an apex forming a radially outermost point, a first and a second sloped surfaces extending radially inwardly from the apex.
3. The rotor assembly as defined in claim 2 , wherein the first sloped surface is shorter than the second sloped surface.
4. The rotor assembly as defined in claim 2 , wherein the apex is located between the first sloped surface and the second sloped surface, the first and second sloped surfaces converging to form the apex.
5. The rotor assembly as defined in claim 2 , wherein the apex is in line with a radial axis extending centrally between two adjacent slots of the rotor disc.
6. The rotor assembly as defined in claim 2 , wherein the sealing tab has a radially offset configuration, wherein the apex forming the radially outermost point on the sealing tab is circumferentially offset from a radial axis extending centrally between two adjacent slots of the rotor disc.
7. The rotor assembly as defined in claim 1 , wherein the sealing tab overlaps a rear surface of two adjacent ones of the blade roots.
8. The rotor assembly as defined in claim 1 , wherein a recessed region is defined in a rear surface of two adjacent ones of the blade roots, the sealing tab overlapping the rear surface of two adjacent ones of the blade roots in the recessed region.
9. The rotor assembly as defined in claim 8 , wherein a contour of an outer periphery of the sealing tab corresponds to that of the recessed region in the rear surface of the two adjacent blade roots.
10. The rotor assembly as defined in claim 8 , wherein a rearmost surface of the sealing tab is flush with the rear surface of the blade roots surrounding the recessed region.
11. The rotor assembly as defined in claim 8 , wherein the sealing tab is housed inside the recessed region, such that a rearmost surface of the sealing tab and the rear surface of the blade root surrounding the sealing tab form a continuous flat surface.
12. The rotor assembly as defined in claim 8 , the recessed region defined in the rear surface of a respective one of the blade roots has a different shape than that of the recessed region defined in the rear surface of an adjacent one of the blade roots.
13. The rotor assembly as defined in claim 1 , wherein the sealing tab is an integral part of the rotor disc.
14. The rotor assembly as defined in claim 1 , wherein the platform and the corresponding platform together define a blade pocket thereunder for receiving secondary air from an upstream side of the rotor assembly.