Blade tip seal

Patent metadata

Field	Value
Publication number	US-10883373-B2
Application number	US-201715448318-A
Country	US
Kind code	B2
Filing date	Mar 2, 2017
Priority date	Mar 2, 2017
Publication date	Jan 5, 2021
Grant date	Jan 5, 2021

Abstract

A blade tip sealing portion forms the distal end of a rotor blade in a turbine engine to reduce or prevent leakage through the blade tip clearance. A rotor assembly comprises a casing, a rotor, and at least one rotor blade coupled to the rotor. The rotor blade comprises a root portion coupled to the rotor, a main airfoil body extending radially from the root portion, and a blade tip sealing portion. The blade tip sealing portion comprises a blade tip platform and a plurality of sealing members. The sealing members are positioned on the blade tip platform at an angle substantially perpendicular to an air flow across the blade tip platform and are spaced to effect overlap of adjacent sealing members in the direction of the air flow.

First claim

What is claimed is:

1. A rotor assembly comprising:
a casing;
a rotor encased by said casing;
and at least one rotor blade coupled to said rotor, each of said at least one rotor blade comprising:
a root portion coupled to said rotor;
a main airfoil body extending radially from said root portion, said airfoil body comprising a pressure side surface and a suction side surface joined at and extending between a leading edge and a trailing edge; and
a blade tip sealing portion forming a distal end of said at least one rotor blade, said blade tip sealing portion comprising:
a blade tip platform facing said casing and extending at least between distal edges of said pressure side surface and said suction side surface of said main airfoil body and extending axially from a front edge proximate the leading edge to a rear edge proximate the trailing edge;
a plurality of sealing members extending radially from said blade tip platform, said sealing members being positioned on said blade tip platform to extend between a pressure side edge and a suction side edge of said blade tip platform at an angle perpendicular to an air flow across said blade tip platform and being spaced between said leading edge and said trailing edge of said main airfoil body to effect overlap of adjacent sealing members in the direction of the air flow; and
the plurality of sealing members being positioned to effect greater spacing between ones of a set of the plurality of sealing members nearer the leading edge or trailing edge of the respective at least one rotor blade than between ones of another set of the plurality of sealing members nearer a mid-chord of the respective at least one rotor blade, wherein an angle of a first one of said plurality of sealing members relative to an axis of rotation of the rotor assembly differs from an angle of a second one of said plurality of sealing members relative to the axis of rotation of the rotor assembly.

2. A rotor assembly comprising:
a casing;
a rotor encased by said casing; and
at least one rotor blade coupled to said rotor, each of said at least one rotor blade comprising:
a root portion coupled to said rotor;
a main airfoil body extending radially from said root portion, said airfoil body comprising a pressure side surface and a suction side surface joined at and extending between a leading edge and a trailing edge; and
a blade tip sealing portion forming a distal end of said at least one rotor blade, said blade tip sealing portion comprising:
a blade tip platform facing said casing and extending at least between distal edges of said pressure side surface and said suction side surface of said main airfoil body and extending axially from a front edge proximate the leading edge to a rear edge proximate the trailing edge;
a plurality of sealing members extending radially from said blade tip platform, said sealing members being positioned on said blade tip platform to extend between a pressure side edge and a suction side edge of said blade tip platform at an angle perpendicular to an air flow across said blade tip platform and being spaced between said leading edge and said trailing edge of said main airfoil body to effect overlap of adjacent sealing members in the direction of the air flow; and
the plurality of sealing members being positioned to effect greater spacing between ones of a set of the plurality of sealing members nearer a mid-chord of the respective at least one rotor blade than between ones of another set of the plurality of sealing members nearer the leading edge or trailing edge of the respective at least one rotor blade, wherein an angle of a first one of said plurality of sealing members relative to an axis of rotation of the rotor assembly differs from an angle of a second one of said plurality of sealing members relative to the axis of rotation of the rotor assembly.

3. The rotor assembly of claim 2 wherein the plurality of sealing members have a uniform radial dimension.

4. The rotor assembly of claim 2 wherein the plurality of sealing members have a differing radial dimension.

5. The rotor assembly of claim 2 wherein each of the plurality of sealing members have a varying radial dimension along a length thereof.

6. A rotor assembly comprising:
a casing;
a rotor encased by said casing; and
at least one rotor blade coupled to said rotor, each of said at least one rotor blade comprising:
a root portion coupled to said rotor;
a main airfoil body extending radially from said root portion, said airfoil body comprising a pressure side surface and a suction side surface joined at and extending between a leading edge and a trailing edge; and
a blade tip sealing portion forming a distal end of said at least one rotor blade, said blade tip sealing portion comprising:
a blade tip platform facing said casing and extending at least between distal edges of said pressure side surface and said suction side surface of said main airfoil body and extending axially from a front edge proximate the leading edge to a rear edge proximate the trailing edge;
a plurality of sealing members extending radially from said blade tip platform, said sealing members being positioned on said blade tip platform to extend between a pressure side edge and a suction side edge of said blade tip platform at an angle perpendicular to an air flow across said blade tip platform and being spaced between said leading edge and said trailing edge of said main airfoil body to effect overlap of adjacent sealing members in the direction of the air flow; and
the plurality of elongated sealing members are positioned to effect non-uniform spacing between ones of a set of the plurality of sealing members nearer the leading edge or the trailing edge of the respective at least one rotor blade than between ones of another set of the plurality of sealing members nearer a mid-chord of the respective at least one rotor blade, wherein an angle of a first one of said plurality of sealing members relative to an axis of rotation of the rotor assembly differs from an angle of a second one of said plurality of sealing members relative to the axis of rotation of the rotor assembly.

7. In a rotor assembly having a casing, a rotor encased by the casing, and a rotor blade coupled to the rotor having a blade tip spaced from the casing, a method of reducing a tip leakage air flow between the blade tip and the casing from a pressure side of the rotor blade to a suction side of the rotor blade during rotation of the rotor, said method comprising:
determining a primary direction of the tip leakage air flow relative to a blade tip chord; and
positioning a plurality of elongated sealing members on a radially outward facing surface of the blade tip, the plurality of elongated sealing members being positioned at an angle perpendicular to the primary direction of the tip leakage air flow and being spaced along the blade tip chord to effect overlap of adjacent sealing members in the direction of the tip leakage air flow;
wherein the plurality of elongated sealing members are positioned to effect non- uniform spacing between ones of a set of the plurality of elongated sealing members nearer a leading edge or a trailing edge of the respective at least one rotor blade than between ones of another set of the plurality of sealing members nearer a mid-chord of the respective at least one rotor blade, wherein an angle of the a first one of said plurality of sealing members relative to an axis of rotation of the rotor assembly differs from an angle of a second one of said plurality of sealing members relative to the axis of rotation of the rotor assembly.

8. The method of claim 7 wherein the plurality of elongated sealing members are positioned to effect greater spacing between ones of a

Assignees

• Rolls Royce Corp

Inventors

• Hall Christopher
• Krautheim M Stephen

Classifications

• F05D2250/181

  ridged · CPC title

• F05D2250/182

  crenellated, notched · CPC title

• F05D2240/11

  Shroud seal segments · CPC title

• F05D2240/307

  related to the tip of a rotor blade · CPC title

• F01D11/122

  with erodable or abradable material (blades having cutting or grinding tips F01D5/20) · CPC title