DE102019201658A1 - PROCEDURE FOR RENEWING AN INTAKE LAYERING OF A CASE-ELECTRIC POWER PLANT - Google Patents

Abstract

The present invention relates to a method for renewing an inlet lining (9) of a turbofan engine (1), namely the inlet lining (9) of the fan (5), in which method the fan (5) is removed; - a molding tool (20) is set; and an inlet lining material (51) is injected with the molding tool (20).

Description

Technical area

The present invention relates to a method for renewing an intake lining of a turbofan engine.

State of the art

Functionally, an aircraft engine is divided into a compressor, combustion chamber and turbine. Air that is sucked in is compressed by the compressor and burned in the downstream combustion chamber with the added kerosene. The resulting hot gas, a mixture of combustion gas and air, flows through the downstream turbine and is expanded in the process. Both the turbine and the compressor are usually constructed in several stages. In the case of a turbofan engine with a fan, the downstream airflow is divided into an internal airflow (primary flow), which enters the combustion chamber, and an external airflow (secondary flow).

In order to reduce leakage, that is, a parasitic air flow past the fan radially on the outside, the fan is surrounded on the outside by an inlet coating. In operation, the blades of the fan brush with their radially outer ends along the inlet coating. If this becomes increasingly worn in the course of its service life (erosion), leaks increase, which can mean a reduction in efficiency.

Presentation of the invention

The present invention is based on the technical problem of specifying an advantageous method for renewing an intake lining of a turbofan engine.

This is achieved according to the invention with the method according to claim 1. In this case, the fan is removed to replace the run-in covering and a running-in covering material is injected with a molding tool.

The molding tool can advantageously predefine its final shape for the run-in covering material so that, for example, no subsequent turning to size is required. It may be necessary to deburr, but this means significantly less effort. With its cavity, into which the running-in lining material is injected, the molding tool defines the radially inwardly facing inner circumferential surface of the renewed running-in lining, along which the blade blades then move later during operation. Injection molding of the running-in covering material, that is to say applying it in a closed cavity, can also improve the material quality, for example, compared to brushing on. In this way, for example, air inclusions can be reduced, which can increase the service life of the renewed run-in covering.

Preferred embodiments can be found in the dependent claims and the entire disclosure, which is to be read at least implicitly with regard to all claim categories. "Axial" or "radial" and "circumferential", as well as the associated directions, refer to the axis of rotation of the fan, which coincides with a longitudinal axis of the engine.

After removing the fan, the inlet lining of the fan is easily accessible axially from the front. Due to the relatively large diameter, the injection molding tool can also be attached easily and there are efficiency advantages compared to a purely manual renewal, for example grinding in connection with a subsequent brushing on of the running-in lining material.

According to a preferred embodiment, the molding tool is applied with a manipulator, which is mounted on the shaft of the turbofan engine instead of the removed fan. The shaft or its axis of rotation can thus be used as a reference, which enables exact positioning or can reduce the positioning effort. The manipulator is preferably mounted on the shaft via an adapter which is rotatably seated on the shaft. The rotary position of the adapter and thus of the manipulator can be changed with a position drive, which is supported on the housing, for example with a roller. A linear drive, for example, can generally be provided as the manipulator, with which the molding tool can be applied radially outwards and removed again radially inwards after the injection molding and curing.

In a preferred embodiment, an articulated arm is provided as a manipulator, which is equipped with actuators and can be moved in an articulated manner (comparable to an articulated arm robot). The molding tool can then be attached by stretching the articulated arm radially outwards and removed again after the injection molding process by kinking the articulated arm. The use of an articulated arm can generally increase flexibility; the molding tool can, for example, also be removed at a slight angle, which can simplify demolding depending on the geometry of the run-in coating. In addition, an articulated arm can also enable adaptation to the effect that different engine types can be processed with the same manipulator; only the molding tool and, if necessary, the adapter for mounting on the shaft then have to be exchanged.

In a preferred embodiment, the running-in coating that is to be renewed is machined to remove material before the molding tool is attached, preferably by milling. In particular, damaged areas can be removed; a completely circumferential material removal can be preferred. In this way, a defined geometry can be created for the attachment of the molding tool; in addition, a surface roughened as a result of the material removal can also improve the adhesion of the run-in coating material then injected on.

A corresponding material removal tool, preferably a milling tool, is attached in a preferred embodiment with a manipulator that is mounted on the shaft instead of the removed fan. The same advantages in terms of alignment and precision result as just discussed for the molding tool. In a preferred embodiment, the material removal tool and the molding tool are attached one after the other with the same manipulator, for example the articulated arm. After the fan has been removed, the manipulator is mounted on the shaft, which then initially carries the material removal tool. After the material has been removed / milled out, the tool is exchanged, with the manipulator preferably remaining mounted on the shaft. After converting to the molding tool, the running-in lining material can then be injected.

According to a preferred embodiment, the molding tool extends only over a segment of a circulating system (that is, not completely encircling) and is attached one after the other in segments. At the boundary between two segments, for example, a tissue can also be injected, which is then torn off; this enables a tight connection between the segments. In general, the run-in coating can be renewed with a single molding tool, but it can also be injected simultaneously with several molding tools in different circulating positions. Several molding tools can also be used sequentially, for example with a view to the required cooling times.

As a result of the limitation to a circumferential segment, the molding tool can, for example, have a width in the circumferential direction of at most 2 m, preferably at most 1.5 m (possible lower limits can be at least 0.5 m or 0.8 m, for example). Limiting the size can be advantageous with regard to the total weight and enable precise handling by the manipulator.

In a preferred embodiment, the molding tool is provided from a fiber composite material, for example a glass or, in particular, carbon fiber reinforced material. This can in turn be advantageous with a view to the weight and thus easy handling by the manipulator.

According to a preferred embodiment, the injection-molded running-in covering material is heated with a heating device and thus hardened. This takes place with the molding tool still attached; this is only removed after it has partially hardened. A hot air blower, for example, with which the molding tool is heated, can be provided as the heating device. A heating device can also be integrated into the molding tool, for example in the form of an electrically conductive spiral, e.g. B. made of carbon fibers. Regardless of the type of heat generation in detail, the process is preferably temperature-controlled, that is, in the area of heat generation or introduction, the temperature is measured with a temperature sensor in order to prevent overheating.

According to a preferred embodiment, the molding tool has a plurality of injection channels which open into the cavity delimited by the molding tool. There are preferably several injection channels distributed around the circumference, particularly preferably also distributed axially. This can enable the running-in covering material to be introduced evenly and thus, for example, help to increase the material quality.

In a preferred embodiment, an injection tool, with which the run-in coating material is injected, is placed one after the other on the individual injection channels. In this case, enema covering material can be injected through an injection channel until it becomes visible on the or through the next adjacent injection channels. The injection tool is then placed on one of these next adjacent injection channels and is again injected into other injection channels until it is visible. With this procedure, empty cavities between the individual injection channels can be prevented. Those injection channels through which the injection has already been carried out can then be closed with a stopper, for example a PTFE stopper. This can enable quick closing and also good cleaning. The injection tool can be attached beforehand, for example with a PTFE adapter piece.

In a preferred embodiment, the running-in lining material is a multi-component material, in particular a thermosetting material. As an example, reference is made to LOCTITE EA 9891 RP AERO. Before the injection, the multicomponent material is preferably mixed in a cartridge, i.e. in a closed container and thus without any significant contact with the outside air. This can prevent the formation of air bubbles in the running-in lining material and thus increase the quality. Prefers the cartridge is also used as an injection tool, comparable to a syringe. In an interior of the cartridge in which the inlet lining material is mixed, a movable piston is then provided with which the inlet lining material can be pushed out of the cartridge. The outlet of the cartridge is connected to the respective injection channel via a pipe or hose, so that the inlet lining material enters the cavity largely without contact with the outside air. In principle, the injection can also be automated, but it can also be done manually.

The invention also relates to an injection device according to claim 15, which has a manipulator and a molding tool. With regard to further device features, express reference is made to the above disclosure.

Figure list

The invention is explained in more detail below with the aid of an exemplary embodiment, with the individual features within the framework of the independent claims also being essential to the invention in other combinations and furthermore no distinction is made between the different claim categories.

• 1 ein Mantelstromtriebwerk in einem schematischen Axialschnitt;
• 2 ein Formwerkzeug zum Anspritzen von Einlaufbelagmaterial, in einer Schrägansicht von vorne;
• 3 das Formwerkzeug gemäß 2 im angesetzten Zustand, und zwar in einem Axialschnitt zusammen mit einem Gehäuseteil;
• 4 die Handhabung des Formwerkzeugs mit einem Manipulator in einer schematischen, teilweise geschnittenen Seitenansicht;
• 5 eine Kartusche zum Anmischen und Injizieren des Einlaufbelagmaterials in einem schematischen Schnitt.

In detail shows

• 1 a turbofan engine in a schematic axial section;
• 2 a molding tool for injecting run-in lining material, in an oblique view from the front;
• 3 the molding tool according to 2 in the attached state, namely in an axial section together with a housing part;
• 4th the handling of the molding tool with a manipulator in a schematic, partially sectioned side view;
• 5 a cartridge for mixing and injecting the running-in lining material in a schematic section.

Preferred embodiment of the invention

1 shows a turbofan engine 1 in an axial section, specifically a turbofan engine. This is functionally divided into compressors 2 , Combustion chamber 3 and turbine 4th . Both the compressor 2 as well as the turbine 4th are each structured in several stages. In the compressor 2 the sucked in air is compressed, it is in the downstream combustion chamber 3 burned with added kerosene. The resulting hot gas is in the turbine 4th expands and drives their rotors; This kinetic energy in turn turns the rotors of the compressor 2 driven. In the case of the turbofan engine, it is also the fan 5 driven. Downstream of this, the air flow divides into a primary flow 6.1 and a secondary stream 6.2 on the outside of the core engine. In order to prevent leaks and thus a loss of efficiency, the blades brush 7th of the fan 5 outside of the housing 8th along a run-in coating 9 , see. also 3 in detail.

To this run-in coating 9 To renew after a certain period of operation, according to the invention, the fan 5 expanded. Then an in 2 Shown molding tool 20th attached and is through injection channels 21st a running-in lining material is injected. A heating device is then used for curing 22nd , in this case a hot air blower, an increased temperature is set (to avoid overheating, the temperature is measured here). How out 2 can be seen which the molding tool 20th shows in an oblique view from the front, it extends over a circulating segment 23 . The molding tool 20th is offset after the injection molding of a respective segment, and the running-in lining material in a subsequent segment is injection molded.

3 shows the molding tool 20th in the attached state. In the area 9 there is the running-in coating, whereby the existing running-in coating is somewhat worn away when the running-in coating material is sprayed on (due to erosion during operation and also due to material-removing pre-processing, see below). The molding tool 20th delimits a cavity on the housing radially inward and also axially 8th The running-in lining material is fed into these through the injection channels 21st brought in. It rests against the roughened surface of the original running-in lining material. The molding tool 20th advantageously specifies a final shape, the injected running-in lining material need not be machined again to remove material apart from deburring.

4th illustrates the handling of the molding tool 20th with a manipulator 40 , namely an articulated arm. This sits on an adapter 41 instead of the expanded fan on the shaft 42 of the turbofan engine 1 is mounted. This enables a comparatively simple and exact positioning. With the articulated arm, the molding tool 20th applied radially and removed again after the run-in lining material has been injected. To change the rotational position is on the adapter 41 an arm 43 mounted, the one position drive 44 wearing. This has a roller on the outside, which is attached to the housing (not shown here) of the turbofan engine 1 so that by turning the roller the manipulator 40 can be brought to another rotational position.

The manipulator 40 can with a material removal tool prior to the injection molding of the running-in lining material 45 be equipped, preferably a milling tool with which the run-in coating 9 can be machined in a material-removing manner (removal of damaged areas, setting of a defined interface).

5 shows an injection tool 50 with which the running-in lining material 51 through the injection channels 21st can be injected. The injection tool includes a cartridge 52 inside of which is the running-in lining material 51 initially held in the form of two separate components, namely as resin 51.1 and as a hardener 51.2 . The two are over a partition 53 separated, which is designed as a film and can be separated to mix the components by moving the plunger 54 with the mixer 55 . The resin 51.1 and the hardener 51.2 are mixed with it with exclusion of air, then the plunger can 54 from the mixer 55 unscrewed and out of the cartridge 52 be pulled out. Then can on a nozzle 56 a hose (not shown) can be screwed on, and the running-in lining material 51 can by lowering the piston 57 from the cartridge 52 pushed out and through the hose through one of the injection openings 21st the cavity of the mold 20th are fed.

List of reference symbols

1

Turbofan engine

2

compressor

2.1

First stage

3

Combustion chamber

4th

turbine

5

fan

6.1

Primary current

6.2

Secondary current

7th

Shovels

8th

casing

9

Run-in coating

20th

Forming tool

21st

Injection channels

22nd

Heating device

23

Circulation segment

40

manipulator

41

adapter

42

wave

43

Arm (for position drive)

44

Position drive

45

Material removal tool

50

Injection tool

51

Run-in lining material

51.1

resin

51.2

Harder

52

cartridge

53

partition wall

54

Plunger

55

mixer

56

Support

57

piston

Claims (15)

Method for renewing an inlet lining (9) of a turbofan engine (1) with a fan (5), namely the inlet lining (9) of the fan (5), in which method - the fan (5) is removed; - A molding tool (20) is attached; and - An inlet lining material (51) is injected with the molding tool (20). Procedure according to Claim 1 , in which the molding tool (20) is applied with a manipulator (40) which is mounted on a shaft (42) of the turbofan engine (1) instead of the removed fan (5). Procedure according to Claim 2 , in which the manipulator (40) is an articulated arm, the molding tool (20) being attached by stretching the articulated arm and being removed again after the run-in covering material (51) has been injected by kinking the articulated arm. Method according to one of the preceding claims, in which the run-in coating (9) is machined to remove material before the molding tool (20) is attached. Procedure according to Claim 4 , in which the run-in coating is machined to remove material by milling. Procedure according to Claim 4 or 5 , in which a material removal tool (45), preferably a milling tool, with a manipulator (40) is applied, which is mounted on a shaft (42) of the turbofan engine (1) instead of the removed fan (5). Procedure according to Claim 6 combined with Claim 2 or 3 at which the Material removal tool (45) and the molding tool (20) are attached one after the other with the same manipulator (40). Method according to one of the preceding claims, in which the molding tool (20) extends over a circumferential segment (23), based on a revolution around an axis of rotation of the fan (5), and the inlet lining material is injected segment by segment one after the other. Method according to one of the preceding claims, in which the molding tool (20) is provided from a fiber composite material. Method according to one of the preceding claims, in which the injected run-in lining material (51) is heated with a heating device (22) and thus hardened. Procedure according to Claim 10 , in which the heating of the sharpened run-in lining material (51) is monitored with a temperature sensor. Method according to one of the preceding claims, in which the molding tool (20) has a plurality of injection channels (21) which open into a cavity delimited by the molding tool (20). Procedure according to Claim 12 , in which an injection tool (50), with which the run-in lining material (51) is injected, is placed one after the other on the individual injection channels (21). Method according to one of the preceding claims, in which the run-in coating material (51) is a multi-component material which is mixed in a cartridge (52), the cartridge (52) then being used as an injection tool (50). Injection device for injection-molding a run-in covering material (51) in a method according to one of the preceding claims, which has: - A manipulator (40) for mounting on a shaft (42) of a turbofan engine (1), - A molding tool (20) which can be attached to the manipulator (40).

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