ROTOR WITH CENTRIFUGALLY OPTIMIZED CONTACT FACES

Abstract

A rotor for a gas turbine having a rotor disk on which there are a plurality of rotor components distributed around the circumference. The rotor disk has a circumferential securing shoulder with a contact face. Retaining faces come to bear against the contact face, each of the retaining faces have a retaining shoulder of the respective rotor component and are designed with a form that complements the contact face. In order to optimize the bearing stresses between the retaining shoulder and the securing shoulder, the retaining face has a smaller radius than the contact face, namely the retaining radius is at least 0.99 times and at most 0.995 times the contact radius. Also provided is an axially extending aperture in the rotor component, the width of which in the circumferential direction is 25% to 75% of the rotor component width in the circumferential direction.

Claims

1. A rotor, comprising: a rotor axis, and a rotor disk that has a circumferential fastening shoulder having a support surface that faces toward the rotor axis and rotates about the rotor axis, and having a plurality of rotor components distributed around the circumference, which each have a retaining shoulder having a retaining surface forming a portion of a surface of revolution that is complementary to the support surface, wherein in each cross section perpendicular to the rotor axis the support surface has a support radius, and the retaining surface has a retaining radius, wherein the retaining radius corresponds to at least 0.99 times and maximally 0.0005 times the support radius, wherein the rotor component has an aperture radially outside the retaining surface, which has a width of at least 0.25 times and maximally 0.75 times the width of the rotor component in the circumferential direction.

2. The rotor as claimed in claim 1, wherein the retaining radius corresponds to at least 0.999 times the support radius.

3. The rotor as claimed in claim 1, wherein the width of the aperture corresponds to at least 0.4 times and/or maximally to 0.6 times the width of the rotor component in the circumferential direction.

4. The rotor as claimed in claim 1, wherein the aperture widens with increasing radius, wherein the difference of the width in the circumferential direction is between 0.75 times and 1.25 times the difference in the radial direction.

5. The rotor as claimed in claim 1, wherein the support surface and the retaining surface are conical, wherein the opening angle is between 30° and 90°, in particular between 45° and 75°.

6. The rotor as claimed in claim 1, wherein the distance in the radial direction from the center of the retaining surface to the aperture corresponds maximally to the distance from the aperture to the an edge of the rotor component in the circumferential direction.

7. The rotor as claimed in claim 1, wherein the rotor component has a shape that extends substantially in the circumferential direction and radially, wherein the retaining shoulder extends in the axial direction.

8. The rotor as claimed in claim 1, wherein the rotor disk and/or a second rotor disk adjacent to the rotor disk have/has a circumferential annular projection spaced apart from the an end face of the rotor disk, and the rotor component has an inner edge portion on the a side that faces toward the rotor axis, wherein the inner edge portion is supported axially on the annular projection, opposite the retaining shoulder.

9. The rotor as claimed in claim 1, wherein the rotor disk has a plurality of blade retaining slots, distributed around the circumference, that extend through axially, and the rotor components cover the blade retaining slots, at least portionally, on an end face of the rotor disk.

10. A rotor component for use in the case of a rotor as claimed in claim 1, having comprising: a retaining shoulder having a retaining surface forming a portion of a surface of revolution that is complementary to the support surface of the rotor disk, wherein in each cross section perpendicular to the rotor axis the retaining surface has a retaining radius, and an aperture, arranged radially outside the retaining surface, which has a width of at least 0.25 times and maximally 0.75 times the width of the rotor component in the circumferential direction, wherein the retaining radius corresponds to at least 0.99 times and maximally to 0.9995 times the intended support radius.

11. The rotor component as claimed in claim 10, wherein the retaining radius corresponds to at least 0.999 times the intended support radius.

12. The rotor component as claimed in claim 10, wherein the width of the aperture corresponds to at least 0.4 times and/or maximally to 0.6 times the width in the circumferential direction.

13. The rotor component as claimed in claim 10, wherein the aperture widens with increasing radius, wherein the difference of the width in the circumferential direction is between 0.75 times and 1.25 times the difference in the radial direction.

14. The rotor component as claimed in claim 10, wherein the retaining surface is conical, wherein the opening angle is between 30° and 90°, in particular between 45° and 75°.

15. The rotor component as claimed in claim 10, wherein the distance in the radial direction from the center of the retaining surface to the aperture corresponds maximally to the distance from the aperture to the an edge in the circumferential direction.

16. The rotor component as claimed in claim 10, wherein the rotor component has a shape that extends substantially in the circumferential direction and radially, wherein the retaining shoulder extends in the axial direction.

17. The rotor as claimed in claim 1, wherein the rotor comprises a gas turbine rotor.

18. The rotor as claimed in claim 5, wherein the opening angle is between 45° and 75°.

19. The rotor component as claimed in claim 14, wherein the opening angle is between 45° and 75°.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Shown schematically in the following figures is an exemplary embodiment for a rotor in the region of the connection between a rotor component and a rotor disk. There are shown:

[0028] In FIG. 1, a portion of the rotor disk, and of the rotor component attached to it, is shown schematically in a longitudinal sectional view;

[0029] FIG. 2 shows the arrangement with the rotor disk and the rotor component in a section transverse to the rotor axis.

DETAILED DESCRIPTION OF INVENTION

[0030] Shown schematically in FIG. 1 is a longitudinal section through the rotor axis, through the rotor disk 01 and the rotor component 11, in the region of the connection between the rotor component 11 and rotor disk 01. It shows the rotor disk 01, having with a blade retaining slot 02 located on the radially outer circumference. This 02 is intended to receive rotor blades (not represented here). The rotor disk 01 in this case has a fastening shoulder 04, which 04 extends in the circumferential direction and in the axial direction, and has a support surface 05 on the side that faces toward the rotor axis. In this exemplary embodiment, merely as an example, the support surface 05 is represented as being slightly inclined and slightly convex. As a rule, a conical form of the support surface may be selected as simple suitable shape. In addition, the rotor disk 01, at a distance from the fastening shoulder 04, has a circumferential annular projection 07 extending radially outward. To that extent, in this exemplary embodiment, a circumferential slot is formed beneath the fastening shoulder 04 and behind the annular projection 07.

[0031] Also shown is the rotor component 11, which 11 is fastened to the rotor disk 01. For this purpose, the rotor component 11 has a retaining shoulder 14, which 14 likewise extends in the circumferential direction and axially. Similarly, the retaining shoulder 14 forms a retaining surface 15, which 15 is arranged on the side that faces radially outward. In this case, the retaining surface 15 and the support surface 05 are realized so as to complement each other. The retaining shoulder 14 is arranged close to the end of the rotor component 11 that faces toward the rotor axis, an inner edge portion 17 being located at the end on the side that faces toward the rotor axis. This 17 in this case is in axial bearing contact with the annular projection 07 of the rotor disk 01. In the case of corresponding centrifugal forces due to the rotation of the rotor, the supporting of the rotor component 11 via the retaining shoulder 14, having the retaining surface 15, on the support surface 05 of the fastening shoulder 04 results in a moment in the rotor component 11 that is supported via the bearing contact of the inner edge portion 17 on the annular projection 07.

[0032] The geometries of the support surface 05 and of the retaining surface 15 are of essential importance, these surfaces bearing against each other over a bearing width 10, as viewed in the axial direction. This means that those surfaces of the fastening shoulder 04, or of the retaining shoulder 14, that are in bearing contact with each other over the bearing width 10 are regarded as a support surface 05 and the retaining surface 15. The support surface 05 in this case, as a surface of revolution about the rotor axis, has a supporting radius 06. In contrast, the retaining surface 15 of the rotor component 11, likewise realized as a portion of a surface of revolution, correspondingly has a retaining radius of 16. For the respective comparison, the support radius 06 and the retaining radius 16 are determined at the same axial position. It is then essential that the support radius 16 is less than the support radius 06, and thus the rotation axis of the support surface 15 is positioned at a distance apart from the rotor axis.

[0033] Furthermore, essential to the achievement of the object, the rotor component 11 has an aperture 12 that extends through the rotor component 11 in the axial direction. This 12 is arranged radially outside the retaining shoulder 14. Advantageously in this case, the aperture 12 is arranged at a certain central distance 23 in the radial direction from the center of the retaining surface 15.

[0034] For this purpose FIG. 2 again shows schematically the arrangement with the rotor disk 01 and the rotor component 11, in a section transverse to the rotor axis, through the fastening shoulder 04 and the retaining shoulder 14, as viewed in the direction away from the rotor disk 01. In this case, the rotor component 11 can be seen with the inner edge portion 17, which 17 bears axially on the annular projection 07.

[0035] Essential now for the invention is consideration of the support surface 05, arranged on the fastening shoulder 04, on the side that faces toward the rotor axis, with the support radius 06 represented here in combination with the retaining shoulder 14, which 14 has the retaining surface 15, having the retaining radius 16, facing radially outward. It can be seen (shown in an exaggerated manner) that here it is provided that the retaining radius 16 has a lesser value than the opposite corresponding support radius 06.

[0036] This shape, with the retaining surface 15 not in full bearing contact with the support surface 05 as first viewed in circumferential direction, results in a uniform bearing contact stress between the two surfaces 05, 15 in the case of high centrifugal forces due to a corresponding rotation of the rotor.

[0037] Radially outside the retaining shoulder 14 is the aperture 12, two webs remaining on the rotor component, on both sides of the aperture 12. The aperture 12, for its part, contributes to the uniform bearing contact stress between the retaining surface 15 and the support surface 05. For this purpose, it is provided that the aperture 12 has a width 22 in the circumferential direction that corresponds approximately to half of the width 21 of the rotor component 11. Accordingly, webs having a web width 24 remain on both sides. With regard to the positioning of the aperture, it is advantageous in this case to take into account that the radial distance 23 from the center of the retaining surface 15 to the aperture 12 is not greater than the web width 24.

[0038] Furthermore, it can be seen that the aperture 12 widens with increasing radius. For optimum stress distribution, it is advantageous if the angle between the side flank of the aperture in the circumferential direction and the radial center axis is approximately 20°. Furthermore, it may advantageously be provided that generous roundings are provided at the upper end of the side flank and at the lower end of the side flank.