Turbine rotor blade of a gas turbine

Patent metadata

Field	Value
Publication number	US-9593584-B2
Application number	US-201314061971-A
Country	US
Kind code	B2
Filing date	Oct 24, 2013
Priority date	Oct 26, 2012
Publication date	Mar 14, 2017
Grant date	Mar 14, 2017

Abstract

The present invention relates to a turbine rotor blade of a gas turbine with a blade tip, said blade tip having at least on its suction side, extending from a stagnation point on the blade leading edge to an intersection point of the suction-side profile line of the blade with a trailing-edge circle, an overhang which is substantially zero at the stagnation point and at the intersection point and which has a maximum value at around 40% of the running length of the suction-side overhang.

First claim

What is claimed is:

1. A turbine rotor blade of a gas turbine, comprising:
a blade profile having a pressure side, a suction side, a leading edge and a trailing edge;
a blade tip at a radially outer end of the blade profile, said blade tip including an overhang positioned on at least the suction side, the suction-side overhang extending between a stagnation point on the blade leading edge to a first intersection point of a suction side profile line of the blade with a trailing-edge circle, the suction-side overhang being substantially zero at the stagnation point and at the first intersection point and having a maximum thickness at between 35% to 45% of a first running length along the suction side surface from the stagnation point to the first intersection point of the suction side profile line;
the suction-side overhang decreasing to less than 50% of the maximum thickness between 50% to 70% of the first running length.

2. A turbine rotor of a gas turbine, comprising a plurality of blades in accordance with claim 1 positioned circumferentially around a rotor hub to form a blade passage between each pair of adjacent blades, wherein the maximum thickness of the suction-side overhang is positioned substantially in a region of a narrowest cross-section of the blade passage.

3. The blade in accordance with claim 1 , wherein the blade tip includes on the pressure side, extending from the stagnation point on the blade leading edge to a second intersection point of a pressure-side profile line of the blade with the trailing-edge circle, a pressure-point overhang which is substantially zero at the stagnation point and at the second intersection point and which has a maximum thickness between 20% to 60% of a second running length along the pressure side surface from the stagnation point to the second intersection point of the pressure-side profile line of the blade.

4. The blade in accordance with claim 3 , and further comprising a circumferential sealing edge at a radially outer edge area of the blade.

5. The blade in accordance with claim 4 , wherein the sealing edge in a region of the suction side overhang has at least one chosen from a reduced height and a zero height positioned between 10% and 30% of the first running length.

6. The blade in accordance with claim 5 , wherein the at least one chosen from a reduced height and a zero height forms an opening in the sealing edge.

7. The blade in accordance with claim 5 , wherein a height of at least one chosen from the suction-side overhang and the pressure-side overhang is at most 10% of a radial length of the blade profile.

8. The blade in accordance with claim 5 , wherein a transition from the blade profile to at least one chosen from the suction-side overhang and the pressure-side overhang is rounded.

9. The blade in accordance with claim 5 , wherein,
on the pressure side, a first portion of an outer edge of the pressure-side overhang flares away from an interior direction of the blade such that radially outward of the blade, a first tangent to the first portion extends away from the interior direction of the blade, the first tangent forming an angle of 10° to 50° with a first vector running in a first radial direction relative to an engine axis;
on the suction side, a second portion of an outer edge of the suction-side overhang tapers toward the interior direction of the blade between 10% and 30% of the first running length such that radially outward of the blade, a second tangent to the second portion extends toward the interior direction of the blade, the second tangent forming an angle of 10° to 50° with a second vector running in a second radial direction relative to the engine axis; and a third portion of the outer edge of the suction-side overhang flares away from the interior direction of the blade between 40% and 100% of the first running length such that radially outward of the blade a third tangent to the third portion extends away from the interior direction of the blade, the third tangent forming an angle of 10° to 50° with a third vector running in a third radial direction relative to the engine axis.

10. The blade in accordance with claim 5 , wherein the height of at least one chosen from the suction-side overhang and the pressure-side overhang is at most 5% of a radial length of the blade profile.

11. The blade in accordance with claim 4 , wherein, where “t” is a blade tip gap in operation, the blade has at least one chosen from the sealing edge having a radial height of 0.5 t to 3 t and the sealing edge having a width of 3 t to 6 t.

12. The blade in accordance with claim 1 , wherein the suction side overhang decreases to approximately 20% of the maximum thickness between 50% to 70% of the first running length.

13. The blade in accordance with claim 12 , wherein the suction side overhang has a maximum thickness at approximately 40% of the first running length.

14. The blade in accordance with claim 1 , wherein the suction side overhang has a maximum thickness at approximately 40% of the first running length.

15. The blade in accordance with claim 1 , wherein the blade tip includes on the pressure side, extending from the stagnation point on the blade leading edge to a second intersection point of a pressure-side profile line of the blade with the trailing-edge circle, a pressure-side overhang which is substantially zero at the stagnation point and at the second intersection point and which has a maximum thickness between 20% to 60% of a second running length along the pressure side surface from the stagnation point to the second intersection point of the pressure-side profile line of the blade.

16. The blade in accordance with claim 1 , and further comprising a circumferential sealing edge at a radially outer edge area of the blade.

17. The blade in accordance with claim 16 , wherein the sealing edge in a region of the suction side overhang has at least one chosen from a reduced height and a zero height positioned between 10% and 30% of the first running length.

18. The blade in accordance with claim 16 , wherein, where “t” is a blade tip gap in operation, the blade has at least one chosen from the sealing edge having a radial height of 0.5 t to 3 t and the sealing edge having a width of 3 t to 6 t.

19. The blade in accordance with claim 16 , wherein a height of at least one chosen from the suction-side overhang and the pressure-side overhang is at most 10% of a radial length of the blade profile.

20. The blade in accordance with claim 1 , wherein,
on the pressure side, a first portion of an outer edge of the pressure-side overhang flares away from an interior direction of the blade such that radially outward of the blade, a first tangent to the first portion extends away from the interior direction of the blade, the first tangent forming an angle of 10° to 50° with a first vector running in a first radial direction relative to an engine axis;
on the suction side, a second portion of an outer edge of the suction-side overhang tapers toward the interior direction of the blade between 10% and 30% of the first running length such that radially outward of the blade, a second tangent to the second portion extends toward the interior direction of the blade, the second tangent forming an angle of 10° to 50° with a second vector running in a second radial direction relative to the engine axis; and a third portion of the outer edge of the suction-side overhang flares away from the interior direction of the blade between 40% and 100% of the first running length such that radia

Assignees

• Rolls Royce Deutschland Ltd & Co Kg
• Rolls Royce Plc

Inventors

• Lehmann Knut
• Herm Manuel

Classifications

• F01D11/08

  for sealing space between rotor blade tips and stator (specially-shaped blade tips therefor F01D5/20) · CPC title

• F01D5/20 Primary

  Specially-shaped blade tips to seal space between tips and stator {(F01D5/225 takes precedence)} · CPC title

• F01D5/141

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

• F05D2240/307

  related to the tip of a rotor blade · CPC title