Sealing metal sheet, turbine, bending tool, and method

Abstract

The invention relates to a sealing metal sheet (200) for receiving a securing metal sheet (20) which is installed during the installation of turbine blades (28) and which has two slots (111, 112) for the securing metal sheet (20), wherein the sealing metal sheet (200) has a groove (100) above the slots (111, 112). The invention also relates to a corresponding bending tool and to a method for same.

Description

[0001] Sealing plate, turbine, bending tool and process

[0002] The invention relates to a sealing plate for securing turbine blades, a tool, a turbine and a method.

[0003] Sealing plates are installed in the disks during turbine blade assembly and secured by locking washers. Locking washers are similar to a pointer threaded through the sealing plate to hold the turbine blades in position.

[0004] Figures 1 and 2 each show a sealing plate 10 with a locking plate 20.

[0005] The sealing plate 10 is preferably angular, preferably square and preferably slightly trapezoidal.

[0006] The sealing plate 10 has two parallel slots 11, 12 (Figs. 1, 2) through which the locking plate 20 is passed and then bent. The end of the locking plate 20 is preferably pointed or triangular.

[0007] Figure 2 shows Figure 1 in cross section.

[0008] The reference symbol 20 ' shows the locking plate 20 in the unbent state.

[0009] The locking plate 20 as a rigid locking plate made of metal usually lies flat on the sealing plate 10.

[0010] The locking plates 20 must be bent upwards through an angle of 25° for removal, as shown in the following illustration. For removal, a wedge-shaped tool is typically driven in from one side, usually with impact, which can lead to damage. Currently, the locking plates 20 are bent upwards during removal using a screwdriver, for example. This is done differently depending on the installer, so the quality of the locking plates 20 varies and reinstallation, and thus approval for further operating hours, is not permitted.

[0011] The locking plate and sealing plate are replaced with a new one, which incurs costs.

[0012] It is therefore an object of the invention to show a sealing plate of a turbine with which the problems are overcome, as well as to show a tool and a method with which removal is carried out in a controlled manner.

[0013] The object is achieved by a sealing plate according to claim 1, a turbine according to claim 4, a tool according to claim 5, and a method according to claim 11.

[0014] The subclaims list further advantageous measures which can be combined as desired to achieve further advantages.

[0015] Figures 1 and 2 show a sealing plate and locking plate according to the state of the art,

[0016] Figure 3 shows a sealing plate according to the invention,

[0017] Figure 4 shows a sealing plate according to the invention with a locking plate in the installed state,

[0018] Figures 5 to 9 show a bending tool in various detailed views.

[0019] The figures and the description represent only one embodiment of the invention.

[0020] Sealing plate 200 Figure 3 shows a sealing plate 200 according to the invention without a locking plate and Figure 4 in the installed state with a locking plate 20 in the rotor and turbine blades 28.

[0021] In contrast to the prior art, the sealing plate 200 now has a "service" groove 100 with a depth preferably up to 50% of the thickness of the sealing plate 200, which promotes the use of a bending tool 30 (Fig. 5 ff) and thus enables the direct reuse of the sealing plates 200.

[0022] The groove 100 is arranged above the two slots 111, 112 (corresponding to the slots 11, 12 of the sealing plate 10 according to the prior art).

[0023] The groove 100 extends in the same direction as the slots 111, 112 and is wider than the slots 111, 112.

[0024] Bending tool 30

[0025] The bending of locking plates 20 is supported by a bending tool 30 ( Fig. 5f f ) so that the risk of damage to components or adjacent components is avoided .

[0026] The bending tool 30 has at least: a base body 33, a bending lever 31 on the base body 33, with which the locking plate 20 is bent, wherein the bending lever 31 preferably extends the base body 33, a preferably fixed clamping jaw 34 and a movable clamping jaw 37 for clamping the locking plate 20 and a clamping lever 49 therefor.

[0027] Interchangeable clamping wedges 40: 40 ', 40 '' are preferably provided on both the fixed clamping jaw 34 and the movable clamping jaw 37. The clamping wedges 40 protrude beyond the base body 33.

[0028] Different clamping wedges 40 can be used for different sealing plates corresponding to different turbine stages and / or different locking plates 20.

[0029] Likewise, instead of this, the fixed clamping jaw 34 and the movable clamping jaw 37 can be wedge-shaped in order to take over the function of the clamping wedges 40.

[0030] Likewise, the bending tool 30 preferably has a bending limiter 46 at the distal end (opposite the bending lever 31), with which the bending angle of the locking plate 20 is limited, as well as a positioning aid 43.

[0031] An example process is as follows:

[0032] 1 ) Preparing the bending tool 30 for use on a specific turbine stage :

[0033] - Mounting the clamping wedges 40 on the bending tool 30

[0034] - Mounting of the bending limiter 46 for the bend for the respective version / application.

[0035] 2 ) Positioning

[0036] Positioning the bending tool 30 over the locking plate 20 to be bent, with the positioning aid 43 the bending tool 30 is hooked onto the free end of the locking plate 20 and centered.

[0037] 3 ) Clamping

[0038] The two clamping wedges 40 are adjusted with the clamping lever 49, in particular by a screwing movement, and finally fixed, in particular by actuating the clamping lever 49. The locking plate 20 is now firmly connected to the bending tool 30 by the contact pressure and the gripping of the clamping wedges 40. The clamping wedges 40 engage in the groove 100 (Figs. 6, 7) and rest beneath the locking plate 20 to be bent.

[0039] 4 ) Adjusting the bending angle

[0040] - Using the bending lever 31, the locking plate 20 is partially bent open at one end until a sufficiently large angle a is reached to allow the combination of sealing and locking plate to be removed from its retaining groove.

[0041] - If the angle a is correct, the bending limit 46 must be secured to prevent accidental adjustment of the bending angles on the other (adjacent) locking plates.

[0042] 5 ) Opening and removal

[0043] - Bend further locking plates 20 by bending them using the bending tool 30 until they stop,

[0044] - After each securing plate 20 has been bent open, check whether the maximum permissible angle has not been exceeded.

[0045] - If the angle was exceeded due to scattering during bending, the bending limit must be readjusted and this step repeated.

[0046] The procedure is identical for all stages of different turbines, regardless of the design of the bending limit.

[0047] - Bend open the remaining locking plates as described above: Place and position - Close the clamping lever - Bend open to the bending limit - Move the sealing plate.

[0048] The advantages are:

[0049] Uniform, safety-compliant working method without temporary tools

[0050] No restriction due to a working position No misuse of tools from a range that are not designed for this work Fast and easy application Defined removal with as little component stress as necessary Multiple use of the locking plates 20 including sealing plates 200 and thus cost savings.

[0051] The bending tool 30 is small, easy to handle, and does not collide with adjacent components. Using the bending tool 30 prevents damage and ensures straight bending. The bending tool 30 is placed over the locking plate 20 to be bent such that the entire locking plate 20 is bent in a straight line and no additional bending radii are created in the locking plate 20. For this purpose, the bending tool 30 is applied as close as possible to the existing bending radius, near the slot 112.

[0052] The clamping wedges 40 are designed to be correspondingly hard, i.e. preferably made of a hardened material, so that deformation is avoided during repeated use.

[0053] The clamping wedges 40 have a specific wedge angle which is optimized for the different thicknesses and lengths of the locking plates 20.

[0054] The clamping wedges 40 used to bend the locking plates 20 have a low surface roughness.

[0055] An exemplary clamping wedge 40 is shown in Figures 8 (top view) and 9 (cross-sectional detail).

[0056] The wedge-shaped ends 41 of the clamping wedges 40 are blunt so that the cutting edge of the wedge 40 does not break under high load.

[0057] To adapt the bending tool 30 to the different widths of the locking plates 20, spacer plates can be mounted between the clamping wedges 40 and the clamping jaws. The spring-loaded positioning aid 43 serves to position the bending tool 30 so that the axis of rotation and the bending axis are aligned with one another. When positioning the bending tool 30, the spring-loaded positioning aid 43 is brought into contact with the blunt end of the locking plate 20. For the bending process, the spring-loaded positioning aid 43 is designed so that it is rigid in one direction so that the axis of rotation and the bending axis are aligned with one another, and elastic in the other direction so that it does not undergo plastic deformation when the locking plate 20 is bent.

[0058] The rotation axis and the bending axis must be aligned so that there is linear contact between the clamping wedge 40 and the locking plate 20. This prevents damage to both the locking plate 20 and the clamping wedges 40. The clamping wedges 40 themselves are positioned close to the existing bend in the locking plate to prevent the locking plate from undergoing additional bending. Figure 6 shows how the clamping wedge 40 rests in the groove 100 of the sealing plate 200 and the spring-loaded positioning aid 43 rests against the end of the locking plate 20.

[0059] The resilient positioning aid 43 is S-shaped and is fastened by a first section to the base body 33 of the bending tool 30. A second section, which extends in an axial direction 51, has a length such that the following third section comes to rest flat on the locking plate 20 and, with a cutting edge 44, engages one end of the locking plate 20 on the sealing plate 200.

[0060] To prevent the user from bending the locking plate 20 too much, there is a bending limiter 46, 46' (Fig. 7). This is a mechanical limiter that interacts with the turbine rotor in a specific direction.

[0061] This can be a threaded pin (Fig. 6) locked with a nut, which is connected to the base body 33 of the bending tool 30 and is locked.

[0062] Or an adapter (Fig. 7) is used which then comes to a stop on the rotor (line 50) when placed on it.

[0063] In both variants 46, 46', the position of the bending limiter 46, 46' is adjustable and can be fixed for subsequent sealing sheets. Therefore, the bending limiter only needs to be adjusted once at the beginning.

Claims

Patent claims 1. Sealing plate (200) for receiving a locking plate (20) which is mounted during the assembly of turbine blades (28) and which has two slots (111, 112) for the locking plate (20), characterized in that the sealing plate (200) has a groove (100) above the slots (111, 112).

2. Sealing plate (200) according to claim 1, wherein the groove (100) is wider than the two slots (111, 112) and / or wider than the locking plate (20) to be bent, so that wedges (40) of a bending tool (30) can be fully inserted before they clamp the locking plate (20), in particular having only one groove (100).

3. Sealing plate (200) according to claim 1 or 2, wherein the groove (100) has a depth of up to 50% in the sealing plate (200).

4. Turbine comprising at least one stage with turbine blades (28) in a rotor disk, wherein sealing plates (200) according to one or more of claims 1, 2 or 3 are mounted on the rotor disk.

5. Bending tool (30) for bending a locking plate (20), wherein the locking plate (20) is preferably arranged on a sealing plate (200), wherein the bending tool (30) has at least: a base body (33), wherein the base body (33) has two clamping jaws (34, 37), in particular a fixed clamping jaw (34) and a movable clamping jaw (37), for receiving the locking plate (20).

6. Bending tool according to claim 5, comprising a fixed clamping jaw (34) and a movable clamping jaw (37) as well as a clamping lever (49) for clamping the clamping jaws (34, 37).

7. Bending tool according to one or both of claims 5 or 6, comprising replaceable clamping wedges (40) on the clamping jaws (34, 37), wherein the clamping wedges have an end (41) which, in the installed state of the bending tool (30), can engage in a groove (100) of the sealing plate (200) under the securing plate (20).

8. Bending tool according to one or more of claims 5, 6 or 7, comprising a particularly resilient positioning aid (43) for contact with a sealing plate (200).

9. Bending tool according to claim 8, wherein the positioning aid (43) has a cutting edge (44) which can encompass one end of a locking plate (20).

10. Bending tool according to one or more of claims 5, 6, 7, 8 or 9, comprising a bending limiter (46).

11. Method for removing a locking plate (20) from a sealing plate, in particular from a sealing plate (200) according to one or more of claims 1, 2 or 3, in which a bending tool (30) according to one or more of claims 5 to 10 is used.

12. Method according to claim 11, in which clamping wedges (40) are positioned under the locking plate (20), in which the bending tool (30) is positioned relative to the locking plate (20) by means of the resilient positioning aid (43), in that the locking plate (20) is fixed by the clamping lever (43) and then the locking plate (20) is bent open by moving the bending lever (31).

13. Method according to claim 11 or 12, wherein a positioning aid (43) is arranged on the locking plate (20).

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