Securement system and method for securing an attachment portion of at least one rotor blade or rotor blade segment in a mounting site of a rotor base

Abstract

A securement system for securing an attachment portion of at least one rotor blade or rotor blade segment in a mounting site of a rotor base. The securement system has at least one holder element and a second holder element, each of which has a holding portion and a connecting portion. The connecting portions can be introduced into the mounting site so as to establish a clip connection and can be locked together in the mounting site. The holding portions are configured so as to fasten the attachment portion of the at least one rotor blade or of the rotor blade segment in the mounting site in the locked state of the connecting portions. Further disclosed is a method for securing an attachment portion of at least one rotor blade or rotor blade segment in a mounting site of a rotor base and a rotor having a securement system.

Claims

1. A securement system for securing an attachment portion of a rotor blade or an attachment portion of a rotor blade segment in a mounting site of a rotor base, comprising: a first holder element with a first holding portion and a first connecting portion; and a second holder element with a second holding portion and a second connecting portion; wherein insertion guides of the second holder element are elastically deformable outward from a resting position by contours of the first connecting portion during introduction of the first and second connecting portions into the mounting site to establish a clip connection in which the first and second holder elements are locked together in the mounting site; and wherein the first and second holding portions are configured so as to fasten the attachment portion of the rotor blade or of the rotor blade segment in the mounting site in a locked state of the first and second connecting portions.

2. The securement system according to claim 1, wherein the first connecting portion has a shaft with a protruding snap-in nose, forming the contours, that is clippable into a clipping receptacle of the second connecting portion so as to establish the clip connection.

3. The securement system according to claim 2, wherein the clipping receptacle has a snap tongue forming one of the insertion guides.

4. The securement system according to claim 3, wherein the snap tongue is elastically deformable between a resting position and a deflected position so as to establish the clip connection.

5. The securement system according to claim 3, wherein at least one of the contours is formed by the snap-in nose on a side away from the first holding portion, and said at least one of the contours is a rounded and/or a tapered insertion contour; wherein the snap-in nose has, on a side toward the first holding portion, a snapping edge that forms a predetermined angle with a longitudinal axis of the shaft; and wherein in the locked state, the snap tongue engages the snapping edge of the snap-in nose.

6. The securement system according to claim 2, wherein the second connecting portion has a recess in which is arranged the snap-in nose in the locked state.

7. The securement system according to claim 2, wherein a longitudinal axis of the shaft and/or a principal axis of extension of the clipping receptacle are angled to conform to a geometry of said mounting site.

8. The securement system according to claim 1, wherein the first and second connecting portions have stops corresponding with one another, wherein via the stops a relative movement between the first and second holder elements is limitable.

9. The securement system according to claim 1, wherein the first and second connecting portions are configured such that in the locked state the first and second connecting portions can be unlocked only destructively.

10. The securement system according to claim 1, wherein the first holding portion and the first connecting portion and/or the second holding portion and the second connecting portion are configured essentially in an L shape in cross-section.

11. A method for securing an attachment portion of a rotor blade or an attachment portion of a rotor blade segment in a mounting site of a rotor base, comprising the steps of: fastening the attachment portion of the rotor blade or the rotor blade segment in the mounting site with a first holding portion of a first holder element and a second holding portion of a second holder element by introducing a first connecting portion of the first holder element and a second connecting portion of the second holder element from opposite sides into the mounting site, elastically deforming insertion guides of the second holder element outward from a resting position by contours of the first connecting portion during introduction of the first and second connecting portions into the mounting site, and locking the first and second connecting portions together in the mounting site by establishing a clip connection.

12. A rotor, comprising: a rotor base, wherein the rotor base has a mounting site; a rotor blade with an attachment portion or a rotor blade segment with an attachment portion, wherein the attachment portion is fastened in the mounting site by a securement system; wherein the securement system includes: a first holder element with a first holding portion and a first connecting portion; a second holder element with a second holding portion and a second connecting portion; wherein the first and second connecting portions are disposed in the mounting site and wherein the first and second connecting portions are locked together in the mounting site by outwardly elastically deformable insertion guides of the second holder element moved from a resting position by contours of the first connecting portion during introduction of the first and second connecting portions into the mounting site; and wherein the first and second holding portions grip the attachment portion.

13. The rotor according to claim 12, wherein with reference to an axis of rotation of the rotor, the mounting site is configured as an axial mounting opening in a radially outward peripheral region of the rotor base.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a schematic lateral section of a rotor, to the rotor base of which a rotor blade is attached with the aid of a securement system according to the invention;

(2) FIG. 2 shows a partially transparent perspective view of the rotor shown in FIG. 1;

(3) FIG. 3 shows a schematic overhead view of a first holder element of the securement system;

(4) FIG. 4 shows a schematic overhead view of a second holder element of the securement system; and

(5) FIG. 5 shows a schematic perspective view of the securement system, wherein the first and second holder elements are locked together.

DETAILED DESCRIPTION OF THE DRAWINGS

(6) FIG. 1 shows a schematic lateral section of a rotor 10 for a thermal gas turbine, for example, for an aircraft engine. FIG. 1 is discussed below as seen in combination with FIG. 2, which shows a schematic and partially transparent perspective view of the rotor 10 shown in FIG. 1. The rotor 10 has a disc-shaped rotor base 12 to which a rotor blade 14 is attached with the aid of a securement system 16 according to the invention. Looking in the radial direction, the rotor blade 14 has a blade portion 18, a blade platform 20 below that, and an attachment portion 22 arranged radially below the blade platform 20 and configured in the present case as a blade foot, being inserted into a mounting site 24 that is in the rotor base 12 and lies axially relative to an axis of rotation of the rotor 10. It can be seen that the securement system 16 is arranged radially below the attachment portion 22 of the rotor blade 14 in the mounting site 24 and grips the attachment portion 22 in a clamp-like manner, such that the rotor blade 14 is fastened to the rotor base 12 on both the front and the back of that base.

(7) The securement system 16 comprises a first holder element 26a, shown in an overhead view in FIG. 3, and a second holder element 26b, shown in an overhead view in FIG. 4. Each holder element 26a, 26b has a holding portion 28a and 28b, respectively, and a connecting portion 30a and 30b, respectively, and the connecting portions 30a, 30b of the holder elements 26a, 26b are inserted to establish a clip connection, on the one hand from the front, and on the other hand from the back, into the mounting site 24 and are locked together in the mounting site 24, such that the holding portions 28a, 28b of the holder elements 26a, 26b secure the attachment portion 22 of the rotor blade 14 (or of a rotor blade segment) in the manner shown in FIG. 1 and FIG. 2 in the mounting site 24. The holding portions 28a, 28b and the connecting portions 30a, 30b of the first and second holder elements 26a, 26b are configured to be essentially L-shaped in cross-section, such that the holding portions 28a, 28b stand at least approximately perpendicular on the connecting portions 30a, 30b.

(8) As can be seen in FIG. 3, the connecting portion 30a of the first holder element 26a has a shaft 32 with two laterally protruding snap-in noses 34a, 34b. To establish the clip connection, the connecting portion 30a is clipped into an appropriately configured clipping receptacle 36 in the connecting portion 30b of the second holder element 26b. For further explanation, FIG. 5 shows a schematic perspective view of the securement system 16, in which the first and second holder elements 26a, 26b are locked together. As can be seen in FIG. 4, the clipping receptacle 36 of the second holder element 26b has two snap tongues 38a, 38b, which serve as inclined insertion guides and are elastically deformed outward from the resting position shown in FIG. 4 when the snap-in noses 34a, 34b are inserted into the clipping receptacle, until the snap-in noses 34a, 34b reach their final assembly positions visible in FIG. 5, where they are arranged in a corresponding recess 40 in the connecting portion 30b. In FIG. 3 one can see that the snap-in noses 34a, 34b have rounded insertion contours 35a, 35b on their sides facing away from the holding portion 28a and toward the clipping receptacle 36, thus facilitating insertion into the clipping receptacle 36.

(9) The recess 40 together with the stops 42a, 42b and the corresponding stops 42c, 42d of the second holder element 26b limits the movement of the first holder element 26a into the clipping receptacle 36 of the second holder element 26b. In the position of the first holder element 26a shown in FIG. 5, the snap tongues 38a, 38b spring back into their resting position shown in FIG. 4 and together with their internal end portions form stops 42e, 42f that cooperate with the snapping edges 44a, 44b of the snap-in noses 34a, 34b to make movement of the first holder element 26a out of clipping receptacle 36 impossible. In the present case the connecting portions 30a, 30b of the first and second holder elements 26a, 26b are configured in such a way that after being locked together, they can no longer be unclipped nondestructively. For this purpose, the snapping edges 44a, 44b form approximately a right angle with a longitudinal axis of the shaft 32. In cooperation with the stops 42e, 42f on the snap tongues 38a, 38b, therefore, it is ensured that the necessary unclipping force is so great that before the unclipping force is achieved, a destruction of at least one of the holder elements 26a, 26b occurs.

(10) As can furthermore be seen in FIG. 3 and FIG. 4, the longitudinal or principal axes of extension of the shaft 32 and of the clipping receptacle 36 do not lie perpendicularly to the principal axes of extension of the respective holding portions 28a, 28b, but rather, are slightly angled so as to conform better to a geometry of the mounting site 24.

(11) The parameter values indicated in the documentation for the definition of processing and measuring conditions for the characterization of specific characteristics of the subject matter of the invention are to be considered as included in the scope of the invention even within the context of discrepancies, for example because of measurement errors, system errors, weighing errors, DIN tolerances and the like.

(12) The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.