US 4,872,812 A · Turbine blade plateform sealing and vibration damping apparatus

Abstract

A gas turbine rotor blade platform sealing and damping system has elongated symmetrical insert elements of equilateral triangular cross-section loosely received within complementary shaped pockets at the spacing gaps between opposing convex and concave airfoil side edges of adjacently mounted blade platforms. The inserts and pockets are relatively configured to provide self-orientation of the inserts into gap sealing and vibration damping engagement with the platform edges when acted upon by centrifugal force due to rotor rotation. The convex platform edge is thickened at the point of closest proximity with the convex side of the airfoil. Alternative embodiments utilize insert grooves for increased leakage of cooling gas past the platform edges and incorporate a central bore for mass reduction.

Claims18

Dependent claims

An insert element to be loosely received between first and second opposing and converging edge surfaces of adjacent blade platforms of a rotor of a gas turbine engine and, in response to centrifugal forces acting thereon due to high rotor rotation speed, to seal a gap between the edge surfaces and to dampen vibration of the blades, said element comprising:

an elongated body having a longitudinal axis and at least three element surfaces configured and arranged symmetrically about said longitudinal axis so that, irrespective of the orientation with which said element is received between the platform edges, the centrifugal forces will drive one of said element surfaces into sealing engagement against the first edge surface and will drive another of said element surfaces into sealing engagement against the second edge surface.

A system for sealing a gap between opposing platform edges of adjacent blades of a rotor of a gas turbine engine, and for damping vibration of the blades, comprising:

a first blade having a first platform edge including a first generally planar edge surface;
a second blade having a second platform edge including a second generally planar edge surface;
said first and second blades being adjacently mounted on said rotor with said first and second platform edges opposingly positioned across a gap and with said first and second edge surfaces relatively configured and positioned to converge radially outwardly toward said gap at an angle of convergence .alpha. and to define the radial outer boundaries of an elongated pocket formed between said platform edges;
and
an elongated insert element loosely received within said pocket and having a plurality of generally planar element surfaces relatively configured and arranged about a central axis so that, irrespective of the orientation with which said insert element is received within said pocket, centrifugal forces acting upon said insert element due to rotor rotation will drive one of said element surfaces into sealing engagement against said first edge surface and another of said element surfaces into sealing engagement against said second edge surface.

2 more elements

Dependencies are inferred from the claim text.

Turbine blade plateform sealing and vibration damping apparatus

Life of this patent

Turbine blade plateform sealing and vibration damping apparatus

Life of this patent

Abstract

Claims18