Rotor blade and rotor blade assembly for a turbomachine

Patent metadata

Field	Value
Publication number	US-12146418-B2
Application number	US-202318217786-A
Country	US
Kind code	B2
Filing date	Jul 3, 2023
Priority date	Jul 12, 2022
Publication date	Nov 19, 2024
Grant date	Nov 19, 2024

Abstract

A rotor blade ( 20 ) for a rotor blade assembly ( 10 ) of a turbomachine ( 1 ) is provided, having an inner rotor blade platform ( 40 ) which extends axially from the rotor blade ( 20 ) with respect to a longitudinal turbomachine axis ( 2 ) and has two opposite circumferential end faces ( 41 ) and a free axial end ( 42 ) whose cross section is radially inwardly and radially outwardly bounded by circular arcs of two concentric circles. The inner rotor blade platform ( 40 ) has a cross section of connection ( 45 ) with the rotor blade ( 20 ) which is bounded radially inwardly by an inner connecting line ( 46 ) and radially outwardly by an outer connecting line ( 47 ). Each of the connecting lines ( 46, 47 ) has a central portion ( 61 ) having a convex curvature.

First claim

What is claimed is:

1. A rotor blade for a rotor blade assembly of a turbomachine,
the rotor blade comprising:
an inner rotor blade platform extending axially from the rotor blade with respect to a longitudinal turbomachine axis and has two opposite circumferential end faces and a free axial end whose cross section is radially inwardly and radially outwardly bounded by circular arcs of two concentric circles,

wherein the inner rotor blade platform has a cross section of connection with the rotor blade, the cross section of connection bounded radially inwardly by an inner connecting line and radially outwardly by an outer connecting line, each of the inner and outer connecting lines:
having a central portion having a convex curvature toward the blade root of the rotor blade or toward the airfoil; and
wherein the cross section of the inner rotor blade platform extends continuously from the cross section of connection with the rotor blade in a direction toward the free axial end of the inner rotor blade platform;
wherein each of the inner and outer connecting lines has two straight portions, each merging tangentially at one circumferential end into the central portion and at an other circumferential end extending toward a respective circumferential end face of the two circumferential end faces, the straight portions having an uncurved shape, a respective curvature portion having a curved shape being located between the other circumferential end and the respective circumferential end face.

2. The rotor blade as recited in claim 1 wherein the straight portions each merge tangentially into the respective curvature portion, the respective curvature portion extending each straight portion toward the respective circumferential end face.

3. The rotor blade as recited in claim 2 wherein the curvature portions extend up to the respective circumferential end faces.

4. The rotor blade as recited in claim 1 wherein the curvature portions which merge with the straight portions each merge tangentially into a respective straight end portion extending the respective curvature portion toward the respective circumferential end face.

5. The rotor blade as recited in claim 4 wherein each respective straight end portion has a curvature of a circle about the longitudinal turbomachine axis.

6. The rotor blade as recited in claim 4 wherein the each respective straight end portion extends up to a corresponding respective end face.

7. The rotor blade as recited in claim 1 wherein the cross section of the inner rotor blade platform extends continuously from the cross section of connection up to the free axial end of the inner rotor blade platform.

8. The rotor blade as recited in claim 1 wherein the cross section of the inner rotor blade platform extends continuously from the cross section of connection up to 80% of a longitudinal extent of the inner rotor blade platform in the direction of a free axial end and has the cross section of the free axial end over the remaining 20%.

9. The rotor blade as recited in claim 8 wherein the cross section of the inner rotor blade platform extends continuously from the cross section of connection up to 85% of a longitudinal extent of the inner rotor blade platform in the direction of the free axial end and has the cross section of the free axial end over the remaining 15%.

10. The rotor blade as recited in claim 9 wherein the cross section of the inner rotor blade platform extends continuously from the cross section of connection up to 90% of a longitudinal extent of the inner rotor blade platform in the direction of the free axial end and has the cross section of the free axial end over the remaining 10%.

11. The rotor blade as recited in claim 10 wherein the cross section of the inner rotor blade platform extends continuously from the cross section of connection up to 95% of a longitudinal extent of the inner rotor blade platform in the direction of the free axial end and has the cross section of the free axial end over the remaining 5%.

12. The rotor blade as recited in claim 1 wherein the inner and outer connecting lines have an identical sequence of portions including the central portion.

13. The rotor blade as recited in claim 1 wherein portions of the inner and outer connecting lines, including the central portion, are at least regionally parallel to and offset from one another.

14. The rotor blade as recited in claim 1 wherein an extremum of the central portion has a predetermined distance from a radially outer end of the circumferential end faces equal to or greater than a distance of the connecting lines from each other.

15. The rotor blade as recited in claim 1 wherein an extremum of the central portion has a predetermined distance from a radially outer end of the circumferential end faces equal to or less than a distance of the connecting lines from each other.

16. The rotor blade as recited in claim 1 wherein an extremum of the central portion is located in the middle of a circumferential extent of the inner rotor blade platform.

17. A rotor blade assembly comprising at least one rotor blade as recited in claim 1 .

18. The rotor blade as recited in claim 4 wherein the straight end portions have a greater extent than the straight portions.

Assignees

• MTU Aero Engines AG

Inventors

• Wittmer Jens
• Uecker Markus
• Feldmann Manfred

Classifications

• F05D2250/141

  circular · CPC title

• F01D11/001 Primary

  for sealing space between stator blade and rotor · CPC title

• F05D2250/711

  convex · CPC title

• F01D5/3007

  of axial insertion type · CPC title

• F05D2250/184

  sinusoidal · CPC title