EP3156135B1 - Covering device for attachment to a component - Google Patents

Description

The invention relates to a covering device for attachment to an at least partially rotationally symmetrical component with a dimensionally stable holding device which is designed to surround a region of the component on the circumference, in accordance with the type defined in claim 1.

Engine components are known from practice, of which certain areas are to be coated in particular in order to achieve a desired strength or durability. These are, for example, rotor or blisk drums, in which regions which cooperate in a sealing manner in the operation of an engine with stator blades are provided with a hard coating, for example a so-called plasma liner. This ensures that the areas are made harder than the stator blades and the stator blades are rubbed off while the engine is operating without damaging the areas on the coating.

Since both blades and so-called blade fillet areas of the rotor drums have sensitive surfaces, they are covered during an abrasive sandblasting process prior to the coating with plasma liners and during the high-energy plasma coating process. In this way, these areas are also protected against undesired adhesion of foreign particles, a so-called overspray. For this purpose it is known from practice to mask the areas not to be coated or component surfaces to be protected by means of masking tapes. The masking tapes are to be cut to suit the rows of blades to be masked and are applied to the rows of blades in individual segments.

Affixing such masking tapes is disadvantageously very time-consuming and prone to errors, the masking tapes also being partial not withstand the coating process to the desired extent. Furthermore, when the masking tapes are removed, residues can adhere to the component surface and are difficult to remove. For the coating of another structurally identical component, new masking tapes are disadvantageously used, so that overall there is a large material requirement, which causes high costs.

From the EP 2 915 590 A1 a device comprising a container, a first cover element and a second cover element is known, by means of which regions of a blisk that are not to be coated, that is to say an integrally designed disc with a blade, can be covered. In order to seal a gap between a cover element and the blisk in the assembled state of the device, a self-adhesive seal made of ceramic fiber paper is provided.

Such a device is difficult to assemble, with the seal first being glued to the blade and then the device comprising many components being installed. In addition, the parts of the device and the seal are time-consuming to remove separately from the blade after machining. A new seal must be provided for machining another structurally identical component, so that this procedure is material and cost-intensive.

The present invention has for its object to provide a covering device for arrangement on a rotationally symmetrical component, which is easy to assemble overall and can be used for several identical components.

According to the invention, this object is achieved with a covering device with the features of claim 1.

There is a cover device of a component of a turbomachine for attachment to the at least partially rotationally symmetrical component with a dimensionally stable Holding device proposed, which is designed to surround a region of the component.

According to the invention, an insertion device that is flexible at least in some areas is provided, which is inserted into the holding device and, when the covering device is in the assembled state, is arranged at least in some areas between the holding device and the component and bears against the component.

The covering device according to the invention has the advantage that it can be assembled simply and quickly overall on the component due to the particularly positive connection of the insertion device to the holding device to protect an area of a component. In addition, the cover device can be completely removed from the component after it has been processed and can be used again in a comparable manner for the next component of identical construction or at least in some areas of a comparable component. The covering device can thus advantageously be used reversibly. A material requirement compared to conventional designs is hereby advantageously reduced, so that the covering device can be used inexpensively. Due to the fact that the insertion device, in the assembled state of the covering device, borders directly on an area of the component at least in some areas, the covering device according to the invention makes it easy to define a defined boundary between the area of the component to be processed, for example, and an area of the component to be protected and protected by the covering device Component achievable.

The insertion device can be fixed in a simple manner, in particular in a reversible manner, to the holding device, the insertion device being connected to the holding device, in particular in a form-fitting manner, in the state mounted on the holding device. Furthermore, means for securely fixing the insertion device to the holding device can also be provided, wherein the insertion device can also be connected to the holding device, for example, via an adhesive connection.

With the covering device according to the invention, components to be coated can be produced in a cost-effective manner in a weight-optimized manner with a desired reliability and safety.

The covering device according to the invention can also be used to protect areas of a component during a manufacturing process, in order to prevent in a simple manner that, for example, surfaces of areas of the component to be protected by the covering device are damaged during the manufacturing process, for example by scratches.

To interact with the component, the covering device according to the invention can have a defined support point. As an alternative to this, the cover device can also be arranged in a floating manner on the component, so that the cover device can be arranged on the component independently of manufacturing-related tolerances that occur in the axial direction.

In an advantageous embodiment of a covering device according to the invention, it is provided that the holding device has at least one leg which, when the covering device is mounted, extends essentially in the radial direction of the component and the insertion device in the radial direction of the component between the leg of the holding device and the component is arranged. In such an embodiment, the covering device can be arranged in a simple manner on the component and a region of the component to be machined can be delimited by the covering device in the region of the leg of the holding device, defined by the covering device.

If the holding device has at least two legs which extend substantially in the radial direction of the component in the assembled state of the covering device, the insertion device being arranged in the radial direction of the component in each case between the legs of the holding device and the component is, the covering device can be arranged particularly easily on a component to be machined. Such a covering device can advantageously be used to delimit two regions of the component which are spaced apart from one another in the axial direction, in each case defined on one side, in particular for a coating process. In addition, by means of such a covering device, an axial region of the component, in particular projecting in the radial direction, can be edged and covered or protected in the axial direction by the covering device, the legs of the holding device in the mounted state of the covering device in particular further radially inward than have a region of the component which is covered by the covering device.

In the case of a cover device that is particularly easy to manufacture and assemble, the holding device and / or the insertion device have an essentially U-shaped cross section, by means of which a region of the component that is not to be machined is preferably separated from in particular two regions of the component that are to be machined . The insertion device is in particular essentially arranged within an interior space formed by the holding device, the insertion device being arranged in the assembled state of the covering device preferably in the entire cross-sectional area of the holding device between the component and the holding device. Damage to the component during assembly of the component is thereby reliably avoided.

In a preferred embodiment of the covering device according to the invention, the insertion device comprises or encompasses an area of the holding device facing the component in the assembled state of the covering device, in particular a leg of the holding device. As a result, the insertion device can be fixed in a simple manner on the holding device and additionally ensured that only the insertion device touches the component when the covering device is in the assembled state. Damage to the component both during assembly of the cover device and in the assembled state of the Covering device by the dimensionally stable holding device is thereby reliably avoided. A defined delimitation of an area of the component to be machined, for example, from the area to be protected by the cover device can be achieved in a simple manner by the cover device if the insert device, when the cover device is in the assembled state, has a sharp-edged area, that is to say in particular, with an area facing the area to be processed small radius.

The holding device is preferably designed with a metallic material, in particular steel, in order to achieve a desired stability. Alternatively, other materials can be used that are characterized by high dimensional stability.

In an advantageous embodiment of the covering device according to the invention, the insertion device is designed with a plastic, in particular an elastomer, for example a rubber, or a silicone. The material of the insertion device is selected in particular in such a way that it both adequately protects the area to be covered by the covering device and, if necessary, also withstands a processing operation of an area adjacent to the insertion device. The material of the insertion device preferably withstands both a roughening surface processing method, such as a sandblasting method, and a thermal coating method, such as a plasma coating method, of the area adjacent to the covering device.

In order to be able to mount the covering device particularly easily and quickly on the component, the holding device has at least two holding elements that can be connected to one another in the circumferential direction via at least one connecting device, one insert element of the insert device being connected to each holding element. The holding elements can, for example, as Half shells and be connected to each other via two connecting devices.

In a structurally simple embodiment of the covering device according to the invention, at least one connecting device is designed as a screw closure and / or snap closure, wherein tolerances on the circumference can be compensated in particular in the region of the connecting device.

If a stop is provided in the area of the connecting device, by means of which a defined position of the holding elements can be fixed relative to one another, damage to the component and damage to the insertion device can be prevented in a simple manner, for example by shearing off during assembly of the covering device.

In an advantageous embodiment of the invention, at least one insert element encompasses a holding element in the circumferential direction, so that the insert element in the assembled state of the covering device lies against an adjacent insert element and / or an adjacent holding element in the circumferential direction of the covering device. As a result, an interior of the covering device in the assembled state of the covering device with the region of the component accommodated therein is sealed off from the surroundings in a simple manner.

In an advantageous embodiment of a covering device according to the invention, at least one supporting device is arranged in a connecting area of two holding elements adjoining one another in the circumferential direction in the mounted state of the covering device, which supports the insertion device on the component in the radial direction of the component. In the assembled state of the covering device, the at least one support device interacts with both the component and the insertion device in the radial direction of the component and is in particular made of the same material as the insertion device.

The covering device according to the invention is intended in particular for covering an area of a component of a turbomachine, in particular an integrally produced rotor drum or blisk drum of a compressor or a turbine, in which a hard layer, for example a plasma liner, is to be applied to an area between two stages of the rotor drum . For coating purposes, the component can be provided with a plurality of covering devices, for example moving blades of different stages of the rotor drum each being covered with a separate covering device.

Both the features specified in the patent claims and the features specified in the subsequent exemplary embodiments of the covering device according to the invention are each suitable, alone or in any combination with one another, for developing the subject matter according to the invention.

Further advantages and advantageous embodiments of a covering device according to the invention result from the patent claims and the embodiment described below with reference to the exemplary embodiment described in the drawing.

Fig. 1

eine stark schematisierte Ansicht eines Rotors eines Strahltriebwerks mit vorliegend sechs jeweils mit Laufschaufeln ausgeführten Stufen, wobei die Laufschaufeln von drei Stufen jeweils mit einer ausschnittsweise ersichtlichen Abdeckvorrichtung abgedeckt sind;

Fig. 2

einen schematisch gezeigten Ausschnitt einer Schnittansicht des Rotors gemäß Fig. 1, wobei die jeweils mit einer Halteeinrichtung und einer Einlegeeinrichtung ausgeführten Abdeckvorrichtungen näher ersichtlich sind;

Fig. 3

eine vereinfachte Draufsicht auf eine Abdeckvorrichtung der Fig. 1 und Fig. 2 in Alleinstellung, wobei die Halteeinrichtung mit zwei als Halbschalen ausgeführten Halteelementen ausgebildet ist, die jeweils mit einem ebenfalls als Halbschale ausgeführten Einlegeelement der Einlegeeinrichtung zusammenwirken;

Fig. 4

eine vereinfachte dreidimensionale Darstellung eines Einlegeelements der Abdeckvorrichtung nach Fig. 1 bis Fig. 3 in Alleinstellung;

Fig. 5

eine vereinfachte Ansicht einer Verbindungseinrichtung der Abdeckvorrichtung gemäß Fig. 1 bis Fig. 4 in Alleinstellung, mittels der die Halteelemente der Halteeinrichtung in Umfangsrichtung miteinander verbindbar sind; und

Fig. 6

eine schematische dreidimensionale Darstellung von drei Stützeinrichtungen in Alleinstellung, welche in montiertem Zustand einer Abdeckvorrichtung gemäß Fig. 1 bis Fig. 5 im Bereich der Verbindungseinrichtung angeordnet sind und das Einlegeelement gegenüber dem Rotor in radialer Richtung abstützen.

It shows:

Fig. 1

a highly schematic view of a rotor of a jet engine with in the present case six stages each with blades, the blades of three stages each being covered with a covering device which is visible in sections;

Fig. 2

a schematically shown section of a sectional view of the rotor Fig. 1 , each with a holding device and an insertion device designed cover devices can be seen in more detail;

Fig. 3

a simplified plan view of a cover of the Fig. 1 and Fig. 2 in isolation, the holding device being designed with two holding elements designed as half-shells, each of which cooperates with an insert element of the inserting device also designed as a half-shell;

Fig. 4

a simplified three-dimensional representation of an insert element of the cover device according to 1 to 3 in isolation;

Fig. 5

a simplified view of a connecting device of the cover device according to 1 to 4 in isolation, by means of which the holding elements of the holding device can be connected to one another in the circumferential direction; and

Fig. 6

is a schematic three-dimensional representation of three support devices on their own, which in the assembled state according to a covering device 1 to 5 are arranged in the region of the connecting device and support the insertion element in relation to the rotor in the radial direction.

Fig. 1 shows a rotor 1 or a blisk drum of a turbomachine, for example a jet engine, which in the present case has six stages 2 to 7. Steps 3 to 7 each have blades 8 integrally connected to a disk wheel, with steps 2 to 7 being firmly connected to one another.

A region 9 to 13 lying in the axial direction A of the rotor 1 between two adjacent stages 3 to 7 interacts with guide vanes of a stator stage during operation of the jet engine. In order to achieve a desired high sealing effect in the respective areas 9 to 13 during operation of the jet engine, sealing devices 14, 15, 16 designed as so-called seals fins are arranged in the areas 9, 10 and 11.

The areas 12 and 13, which are arranged in the axial direction A of the rotor 1 between the fourth stage 5 and the fifth stage 6 or between the fifth stage 6 and the sixth stage 7 of the rotor 1, are designed without seal fins and act in Operation of the jet engine directly together with guide vanes from stator stages. During operation of the jet engine, the guide blades could come into contact with the respective areas 12, 13. The areas 12, 13 have a sufficiently high hardness for this that the guide vanes on the areas 12, 13 are rubbed off and the areas 12, 13 themselves are not damaged.

During the manufacture of the rotor 1, the surfaces 12, 13 of the regions 12, 13 which face essentially outward in the radial direction R of the rotor 1 are provided with a hard layer, for example a so-called plasma liner. In order to be able to apply the hard layer to the areas 12, 13 in a defined manner and to protect the rotor blades 8 of the stages 5, 6, 7, these are each covered with a covering device 20, 21, which surrounds the rotor blades 8 of the stages 5, 6, 7, 22 covered.

The covering devices 20, 21, 22 have an essentially corresponding structure, so that the covering device 21 is described below as representative of the covering devices 20 and 22.

In the 2 to 4 Cover device 21, which can be seen in more detail, has a dimensionally stable holding device 24 with a U-shaped cross section, which in the present case is made of steel. The holding device forming a steel jacket 21 here protects the blades 8 of the fifth stage 6 from thermal and mechanical loads during machining of the areas 12 and 13 and is here with two radial legs 25, 26 extending essentially in the radial direction R of the rotor 1 and one with the radial legs 25, 26 in an area connecting the rotor 1 facing away and extending essentially in the axial direction A of the rotor 1 27 executed. The legs 25, 26, 27 basically have an essentially constant wall thickness in the present case. Only in a region facing the rotor 1 is a wall thickness of the radial limbs 25, 26 essentially halved in the axial direction A of the rotor 1.

In these areas, the holding device 24 interacts with a flexible insertion device 30, which here consists of silicone and is held in position by the holding device 24. The insertion device 30, like the holding device 24, has a U-shaped cross section with two radial legs 31, 32 and an axial leg 33 connecting the radial legs 31, 32 in a region facing away from the rotor 1. The legs 31, 32, 33 of the insertion device 30 are also designed here with an essentially constant wall thickness.

The radial limbs 31, 32 of the insertion device 30 encompass the radial limbs 25, 26 of the holding device 24 in a region facing the rotor 1, so that the radial limbs 31, 32 of the insertion device 30 encompass a region of the radial limbs 25, 26 in the axial direction A of the rotor 1 on both sides surround and thereby fix the insertion device 30 on the holding device 24. Thus, the insertion device 30 can be fixed together with the holding device 24 on the fifth stage 6 of the rotor 1.

In the radial direction R of the rotor 1, the radial legs 31, 32 of the insertion device 30 are arranged between the radial legs 25 and 26 of the holding device 24 and the rotor 1, the radial legs 31, 32 of the insertion device 30 in a region facing the rotor 1 are adapted to the shape of the blades 8 in an inlet edge region and an outlet edge region of the blade fillet of the fifth stage 6 and, when the cover device 21 is mounted, both in the radial direction R of the rotor 1 on the rotor 1 and on the holding device 24 concerns. On a side facing away from the rotor blades 8 in the axial direction A of the rotor 1, the radial legs 31, 32 preferably have a sharp edge, so that the area 12 or 13 to be coated is exactly defined by the radial legs 31, 32.

The insertion device 30 is arranged almost completely in an inner space 40 formed by the legs 25, 26, 27 of the holding device 24, the radial legs 31, 32 of the insertion device 30 abutting against the radial legs 25, 26 of the holding device 24 and the axial leg 33 of the insertion device 30 in the present case in the radial direction R of the rotor 1 with respect to the axial leg 27 of the holding device 24. The axial legs 27 and 33 of the holding device 24 and the insertion device 30 can, however, also abut one another.

As especially in Fig. 2 can be seen, in the assembled state of the covering device 21, the insertion device 30 is arranged in all areas of the fifth stage 6 on a side of the holding device 24 facing the fifth step 6, so that the holding device 24 does not engage with the moving blades 8 when the covering device 21 is installed fifth level 6 can come into contact and damage it.

The blades 8 of the fifth stage 6 are further delimited from an environment by the covering device 21, so that the blades 8 are reliably protected against external influences, for example during machining operations of the areas 12, 13.

Fig. 3 shows a top view of the covering device 21 in isolation, it being evident that the holding device 24 is formed with two holding elements 35, 36, each of which extends over at least approximately 180 ° in the circumferential direction U of the rotor 1 and is constructed at least approximately identically. An insertion element 38 or 39 of the insertion device 30 is assigned to each holding element 35 or 36, wherein the insertion elements 38 or 39 are each arranged essentially in an interior space 40 formed by the holding elements 35 and 36.

The insertion elements 38 and 39 have a greater extent in the circumferential direction U of the rotor 1 than the holding elements 35 and 36 and encompass or encompass the holding elements 35 and 36 in the circumferential direction U of the rotor 1.

To arrange the cover device 21 on the rotor 1, the holding elements 35, 36 are two in Fig. 5 Connection devices shown in isolation and designed as screw connections 42, 43 can be connected to one another, by means of which circumferential tolerances of the rotor 1 can be compensated for. The screw connections 42, 43 screwed to a holding element 35, 36 each have a stop 44 in order to be able to screw the holding elements 35, 36 to one another with a predefined dimension. In this way, damage to both the rotor 1 and the insert elements 38, 39 can be avoided in a simple manner when the covering device 21 is arranged on the rotor 1.

In order to ensure that the insert elements 38, 39 are securely held in their position in the assembled state of the covering device 21 also in the area of the screw connections 42, 43, three support elements 45, 46, 47 of essentially identical construction are arranged in this area. In the assembled state, the support elements 45, 46, 47 interact in the radial direction R of the rotor 1 with both the insertion elements 38, 39 and also with the rotor 1 and prevent the insertion elements 38, 39 from moving in this area in the radial direction R in can move to an undesirable extent.

The covering devices 20 and 22 differ from the covering device 21 described in more detail above in particular by the length of their radial limbs 25, 26, 31, 32 in the radial direction R of the rotor 1, these in each case depending on the shape of the rotor 1 in the region of the respective step 5 , 6, 7 are adjusted.

The covering devices 20, 21, 22 described in more detail above can be used in particular for coating the areas 12, 13. Such a coating can be carried out using the steps described in more detail below.

First, the covering devices 20, 21, 22 are attached to the rotor 1 to the extent explained in more detail above, the covering device 20 being the moving blades 8 of the fourth stage 5, the covering device 21 being the moving blades 8 of the fifth stage 6 and the covering device 22 being the moving blades 8 the sixth level 7 covers. The areas 12, 13 are then sandblasted. This is followed by a cleaning process for the areas 12, 13, which is carried out, for example, using a so-called plasma flame. After the rotor 1 has been preheated to a predefined temperature, the regions 12, 13 are provided with an adhesive base which, for example, consists of nickel aluminum and is sprayed on as a liquid metal. Finally, the hard layer, in the present case a plasma liner representing a ceramic material, is applied to the areas 12, 13. The covering devices 20, 21, 22 can then be removed from the rotor 1.

After the processing of the areas 12, 13 is complete, the covering devices 20, 21, 22 can be used to the same extent for processing corresponding areas of a further, in particular structurally identical rotor.

Reference list

1

rotor

2 to 7

Stage of the rotor

8th

Moving blades of the steps

9 to 13

Areas of the rotor

14 to 16

Sealing devices

20,21,22

Cover device

24th

Holding device

25, 26

Radial leg of the holding device

27

Axial leg of the holding device

30th

Insertion device

31, 32

Radial leg of the insertion device

33

Axial leg of the insertion device

35, 36

Holding element of the holding device

38, 39

Insertion elements of the insertion device

40

inner space

42, 43

Connecting device; Screw connection

44

attack

45, 46, 47

Support elements

A

axial direction of the rotor

R

radial direction of the rotor

U

Circumferential direction of the rotor

Claims (12)

1. Cover device (20, 21, 22) of a component (1) of a turbomachine for attachment to the component (1), which is of rotationally symmetrical design at least in certain regions, having a holding device (24) of dimensionally stable design and formed to enclose the circumferential side of a region (5, 6, 7) of the component (1), characterized in that an insert device (30) is provided which is of flexible design at least in certain regions, is inserted in the holding device (24), is arranged, in the mounted state of the cover device (20, 21, 22), at least in certain regions between the holding device (24) and the component (1), and bears against the component (1).
2. Cover device according to Claim 1, characterized in that the holding device (24) has at least one limb (25, 26) extending substantially in the radial direction (R) of the component (1) in the mounted state of the cover device (20, 21, 22), wherein the insert device (30) is arranged between the limb (25, 26) of the holding device (24) and the component (1) in the radial direction (R) of the component (1).
3. Cover device according to one of Claims 1 or 2, characterized in that the holding device (24) has at least two limbs (25, 26) extending substantially in the radial direction (R) of the component (1) in the mounted state of the cover device (20, 21, 22), wherein the insert device (30) is arranged, respectively, between the limbs (25, 26) of the holding device (24) and the component (1) in the radial direction (R) of the component (1).
4. Cover device according to one of Claims 1 to 3, characterized in that the holding device (24) and/or the insert device (30) have/has a substantially U-shaped cross section.
5. Cover device according to one of Claims 1 to 4, characterized in that the insert device (30) encompasses or engages, in the mounted state of the cover device (20, 21, 22), around a region of the holding device (24) which faces the component (1).
6. Cover device according to one of Claims 1 to 5, characterized in that the holding device (24) is made with a metallic material, in particular steel.
7. Cover device according to one of Claims 1 to 6, characterized in that the insert device (30) is made with a plastic, in particular an elastomer or a silicone.
8. Cover device according to one of Claims 1 to 7, characterized in that the holding device (24) has at least two holding elements (35, 36) which can be connected to one another via at least one connecting device (42, 43) in the circumferential direction (U) of the component (1), wherein in each case an insert element (38, 39) of the insert device (30) is connected to a holding element (35, 36).
9. Cover device according to Claim 8, characterized in that at least one connecting device (42, 43) is designed as a screw fastener and/or snap-action fastener.
10. Cover device according to either of Claims 8 and 9, characterized in that a stop (44) is provided in the region of the connecting device (42, 43), by means of which stop a defined position of the holding elements (35, 36) with respect to one another can be set.
11. Cover device according to one of Claims 8 to 10, characterized in that at least one insert element (38, 39) engages around a holding element (35, 36) in the circumferential direction (U) such that the insert element (38, 39) bears against a neighbouring insert element (38, 39) and/or a neighbouring holding element (35, 36) in the mounted state of the cover device (20, 21, 22).
12. Cover device according to one of Claims 8 to 11, characterized in that at least one support device (45, 46, 47) is arranged in a connection region of two holding elements (35, 36) or insert elements (38, 39) which are adjacent to one another in the mounted state of the cover device (20, 21, 22).

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