Blade for axial compressor rotor

Patent metadata

Field	Value
Publication number	US-9908170-B2
Application number	US-201414317354-A
Country	US
Kind code	B2
Filing date	Jun 27, 2014
Priority date	Feb 3, 2014
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

A blade for a compressor rotor including a blade root at a first end of the blade connected to the compressor rotor and a blade tip extending from second end of the blade. The blade tip extends up to 20% of a span of the blade from the second end towards the first end. The blade tip is disposed such that a first segment of the blade tip defines a positive dihedral angle and a second segment of the blade tip defines a negative dihedral angle. The positive and negative dihedral angles defining a twist of the blade tip relative to the face of the blade, wherein the blade remains untwisted along the span from outside of the blade tip.

First claim

What is claimed is:

1. A blade for a compressor rotor comprising:
a blade root at a first end of the blade connectable to the compressor rotor; and
a blade tip extending from a second end of the blade towards the first end, the first end and the second end defining a face of the blade between them, the face extending chordally between a first extremity and an opposite second extremity along a chord of the blade, a span of the blade extends between the first end and the second end, the blade tip extending up to 20% of the span from the second end towards the first end, a first segment of the blade tip extending from the first extremity to a first position along the chord, a second segment of the blade tip extending from the second extremity to a second position along the chord, the first segment defining a positive dihedral angle at the second end and the second segment defining a negative dihedral angle at the second end relative to the face of the blade, the positive and negative dihedral angles defining a split dihedral twist relative to a conventional rotor blade, wherein the blade is defined by the conventional rotor blade along the entire span outside of the blade tip.

2. A blade as claimed in claim 1 , wherein the first position and the second position are a same position.

3. A blade as claimed in claim 1 , wherein the face of the blade includes a first surface and a second opposed surface, the first surface is convex shaped and the second surface is concave shaped.

4. A blade as claimed in claim 3 , wherein the face of the blade includes a first edge and a second edge, the first edge and the second edge define a width of the blade between them, the width is orthogonal to the span, the first edge and the second edge are offset with respect to the face of the blade, and when in use, the first edge is positioned upstream from the second edge.

5. A blade as claimed in claim 4 , wherein the first edge is connected to the first extremity of the blade tip and the second edge is connected to the second extremity of the blade tip.

6. A blade as claimed in claim 4 , wherein said blade tip is twisted towards the second surface from a centre of gravity of the blade to the first edge, the centre of gravity being disposed midway of the chord of the blade.

7. A blade as claimed in claim 4 , wherein said blade tip is twisted towards the first surface from a centre of gravity of the blade to the second edge, the centre of gravity being disposed midway of the chord of the blade.

8. A blade as claimed in claim 1 , wherein the blade has a plurality of airfoil shaped cross-sections, and centres of gravity of the plurality of airfoil shaped cross-sections are collinear and runs through a middle of the blade over the entire span of the blade.

9. A method for making a blade for a compressor rotor, the blade having a first edge and a second edge spaced apart along a chord of the blade, the blade having a first end and a second end spaced apart along a span of the blade, the method comprising:
twisting a first segment of the blade in a first direction over an area of the blade disposed at up to 20% of the span from the second end, and twisting a second segment of the blade in a second direction over the area of the blade disposed at up to 20% of the span of the blade from the second end of the blade, the first segment extending from the first edge to a first position along the chord and the second segment extending from the second edge to a second position along the chord, the first segment defining a positive dihedral angle at the second end and the second segment defining a negative dihedral angle at the second end relative to a face of the blade, resulting in forming a split dihedral twist at a blade tip region relative to a conventional rotor blade, wherein the blade is defined by the conventional rotor blade along the entire span outside of the blade tip region.

10. The method of claim 9 , further comprising: forming an attachment at the blade root region to attach the blade to the rotor.

11. The method of claim 9 , wherein the first position and the second position are a same position.

12. A compressor rotor comprising:
a plurality of blades, at least one of the plurality of blades including:
a blade root at a first end of the at least one of the plurality of blades connectable to the compressor rotor; and
a blade tip at a second end of the at least one of the plurality of blades, a span of the at least one of the plurality of blades extends between the first end and the second end, the first end and the second end defining a face of the blade between them, the face extending chordally between a first extremity and an opposite second extremity along a chord of the blade, the blade tip extending up to 20% of the span from the second end towards the first end, a first segment of the blade tip extending from the first extremity to a first position along the chord, a second segment extending from the second extremity to a second position along the chord, the first segment defining a positive dihedral angle at the second end and the second segment defining a negative dihedral angle at the second end relative to the face of the blade, the positive and negative dihedral angles defining a split dihedral twist relative to a conventional rotor blade, wherein the at least one of the plurality of blades is defined by the conventional rotor blade long the entire span outside of the blade tip.

13. A compressor rotor as claimed in claim 12 , wherein the first position and the second position are a same position.

14. A compressor rotor as claimed in claim 12 , wherein the face of the at least one of the plurality of blades includes a first surface and a second opposed surface, the first surface is convex shaped and the second surface is concave shaped.

15. A compressor rotor as claimed in claim 14 , wherein the face of the at least one of the plurality of blades includes a first edge and a second edge, the first edge and the second edge define a width of the at least one of the plurality of blades between them, the width is orthogonal to the span, the first edge and the second edge are offset with respect to the face of the at least one of the plurality of blades, and when in use, the first edge is positioned upstream from the second edge.

16. A compressor rotor as claimed in claim 15 , wherein the first edge is connected to the first extremity of the blade tip and the second edge is connected to the second extremity of the blade tip.

17. A compressor rotor as claimed in claim 15 , wherein said blade tip is twisted towards one of the first surface and the second surface from a centre of gravity of the blade to the first edge, the centre of gravity being disposed midway of a chord of the blade.

18. A compressor rotor as claimed in claim 12 , wherein the at least one of the plurality of blades has a plurality of airfoil shaped cross-sections, and centres of gravity of the plurality of airfoil shaped cross-sections are collinear and runs through a middle of the at least one of the plurality of blades over the entire span of the at least one of the plurality of blades.

Assignees

• Indian Inst Technology Bombay
• Pratt & Whitney Canada
• Pratt & Whitney Canada

Inventors

• Roy Bhaskar
• Amboor Pradeep M
• Halbe Chaitanya V
• Yu Hong
• Townsend Peter

Classifications

• Y10T29/49336

  Blade making · CPC title

• F05D2250/71

  curved · CPC title

• F04D29/324

  Blades · CPC title

• F04D19/02

  Multi-stage pumps · CPC title

• F01D5/141

  Shape, i.e. outer, aerodynamic form (F01D5/148 - F01D5/20 take precedence; blade construction F01D5/147) · CPC title