Rotor disk, rotor and method for maintaining rotor disk
By introducing the outer convex portion of the pig ear shape and the blade root in the turbine blade disk tank, the problem of cracks in the groove in the prior art is solved, and the effect of reducing weight and extending service life is achieved.
Patent Information
- Application Number
- CN202380025976.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-03-10
- Filing Date
- 2023-01-20
- Publication Date
- 2024-12-13
AI Technical Summary
The groove design of existing turbine blade discs is prone to cracks during use, which leads to difficulty in repair and cannot effectively reduce weight.
A rotor disk groove is designed, the groove contains an outer convex portion in the shape of a pig ear, which is used to complement the upper protrusion of the blade root, form a cavity structure, reduce the effect of radial forces, and extend outside the recessed portion of the groove. The protrusions are used to enhance stability and avoid crack formation.
With this design, cracks are reduced, the necessity of brazing or fusion welding is avoided, the durability and lightweight properties of the rotor disk are improved, and the maintenance and manufacturing process is simplified.
Smart Images
Figure CN119137354A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to an improved groove design for a disk of a turbine blade, in particular for reducing weight and / or avoiding crack formation, a rotor and a method. Background Art
[0002] The turbine blades of a turbine, such as a steam turbine or a gas turbine, are held in corresponding slots in a disk (rotor disk) of the turbine.
[0003] In this case, the groove is designed complementary to the blade root, which is designed in particular in the manner of a fir-tree-shaped or hammer-head-shaped design.
[0004] An example of this is given in DE 3736836 A1. Figure 1 or in DE 2549112 as shown in the drawings.
[0005] In the case of repairs, the grooves of the discs sometimes have cracks.
[0006] The findings must be closed by brazing or welding, or new, lighter blades must be installed, whereby the disk can be further used. Summary of the invention
[0007] SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems.
[0008] This object is achieved by a groove design of a rotor disk according to claim 1 , a rotor according to claim 5 and a method according to claim 6 .
[0009] Further advantageous measures are listed in the dependent claims, which can be combined with one another as desired in order to achieve further advantages. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The accompanying drawings show
[0011] Figure 1 shows a blade root in a slot according to the prior art,
[0012] Figure 2 One embodiment of the present invention is shown. DETAILED DESCRIPTION
[0013] The drawings and the description of the alternatives are merely exemplary embodiments of the invention.
[0014] Figure 1 A cross section or side view of a slot 2 ′ in a rotor disk 1 ′ according to the prior art is shown, which has a blade root 77 .
[0015] A plurality of rotor disks, in particular on a shaft, form the rotor.
[0016] The groove 2 ′ of the rotor disk 1 ′ has a bottom 19 .
[0017] The groove 2 ′ likewise has a longitudinal axis 30 (radial direction), which is also the longitudinal axis 30 of a turbine blade or blade root 77 (not shown in detail).
[0018] The blade root 77 is placed and seated in the groove 2 ′ and is held there in the radial direction 5 by the design of the groove 2 ′.
[0019] The groove 2 ′ has, on both sides of the longitudinal axis 30 at the same height, respectively an upper depression 20 ′, into which respectively an upper projection 40 ′ of the blade root 77 projects and rests in a complementary manner.
[0020] For the sake of simplicity, reference numerals in the figures are not always used on each side and at the same axial height.
[0021] The upper projection 40 ′ of the blade root 77 is preferably designed in the form of a hammerhead or, in this case, preferably in the form of a truncated cone.
[0022] Correspondingly, the upper depression 20 ′ of the groove 2 ′ is designed to be complementary to the upper projection.
[0023] In this case, the blade root 77 preferably has two further projections 40 ″, 40 ′″ on each side.
[0024] Along the longitudinal axis 30 towards the bottom 19 , the groove 2 ′ therefore has a plurality of, in this case preferably two, further depressions 20 ″, 20 ″′ on both sides.
[0025] The blade root 77 may have one, two or three projections 40 (this also applies to the invention).
[0026] In particular, when radial forces act in the radial direction 5 on the blade and the blade root 77 during use, the upper projection 40 ′ of the blade root 77 comes to bear against the upper bearing surface 23 ′ of the rotor disk 1 .
[0027] Of course, a certain tolerance is given as the gap between the blade root 77 and the groove 2 ′.
[0028] The end of the blade root 77 is preferably spaced apart from the base 19 .
[0029] According to the present invention, according to Figure 2 And based on Figure 1 At least one recessed portion 20 ′, 20 ″, 20 ″′ (= 20 ) of the groove 2 has another protruding portion 33 ′, 33 ″, 33 ″′ (= 33 ) extending from the recessed portion 20 .
[0030] Preferably, the outer projection 33 is present at the same radial height on both sides in the depression 20 .
[0031] Preferably, the outer projection 33 extends on both sides of the longitudinal axis 30 , preferably in each recess 20 .
[0032] The outer projection 33 is preferably arranged only in the upper region of the depression 20 , ie does not extend over the entire extent of the top surface of the truncated cone of the projection 40 or of the depression 20 .
[0033] Viewed transversely to the longitudinal axis 30 , the projection 33 widens the depression 20 only in certain areas.
[0034] Viewed in cross section, the projection 33 initially extends almost perpendicularly to the longitudinal axis 30 and then extends back in a curved manner.
[0035] The outer projection has the shape of a pig's ear.
[0036] In the installed state of the blade root 77 and the rotor disk 1 , a cavity is thus formed which is the outer projection 33 .
[0037] The dashed line 22 in the lower depression 20"' near the bottom 19 is a depression according to the prior art ( Figure 1 ).
[0038] The dashed line course 22 is continuously curved.
[0039] The rotor disk 1 has a plurality of slots 2 .
[0040] Depending on the application, projections are present in the respective groove 2 , ie the groove 2 may have a different number of projections 33 , or only certain depressions 20 , in particular only the upper depression 20 ′, may have projections 33 .
[0041] Other variations are conceivable.
[0042] For the rotor, a plurality of rotor disks 1 are used. Each rotor disk can have a groove 2 which is equipped with protrusions 33 in different ways.
[0043] During regular maintenance or in the case of repairs, such a depression can be produced preventively starting from the course 22 according to the prior art, or a crack can be machined and not closed by soldering or welding, but rather machined in the shape according to the invention and retained in this manner.
[0044] Likewise, all newly manufactured rotor disks 1 have such an outer projection 33 .
Claims
1. A rotor disk (1), The rotor disk has grooves (2) for receiving blade roots (77) of turbine blades. wherein the groove (2) has a plurality of depressions (20', 20", ...) along its longitudinal axis (30) for the projection (40', 40", ...) of the blade root (77) and complementary thereto, wherein an axial protrusion (33', ...) is present in at least one recess (20', 20", ...), In particular, the plurality of recessed portions (20) of the groove (2) have protruding portions (30).
2. The rotor disk according to claim 1, The rotor disk has in the groove (2) at least one contact surface (23) for a projection (40) of the blade root (77), The outer projection (33) is formed at the starting point of the contact surface (23) when viewed in the longitudinal direction (30) toward the base (19).
3. The rotor disk according to claim 1 or 2, In this case, the projection (33) widens the depression (20) only in certain areas, viewed transversely to the longitudinal axis (30).
4. A rotor disk according to one or more of claims 1, 2 or 3, The outer projection (33) extends transversely to the longitudinal axis (30) and is of U-shaped design.
5. A rotor having at least one rotor disk (1) according to one or more of claims 1, 2, 3 or 4.
6. A method for maintaining at least one rotor disk (1), At least one protrusion (33', ...) is machined into at least one depression (40', 40", ...) of at least one groove (2), in particular into all depressions (40', 40", ...).