DE102018222108A1 - METHOD FOR PRODUCING A SEALING DEVICE - Google Patents

Abstract

The invention relates to a method for producing a sealing device (20), which has a carrier seal (21) with a carrier (23) and a sealing element (24), and a housing (22), the sealing element (24) being attached to the Carrier (23) extends and the housing (22) surrounds the carrier (23), in which method
- a first part (22.1) of the housing (22) is produced,
- The carrier seal (21) with the carrier (23) is then positioned on the first part (22.1) of the housing (22),
- and then in a 3D printing process, a second part (22.2) of the housing (22) is printed on the first part (22.1), the first and the second part (22.1, 22.2) of the housing (22) together holding the carrier ( 23) partially enclose viewed in a sectional plane perpendicular to its longitudinal axis (27).

Description

Technical field

The present invention relates to a method for producing a sealing device with a carrier seal.

State of the art

A carrier seal can be used, for example, in an aircraft engine in order to seal a moving component against a gas flow in the engine. Wire pieces or fibers are typically arranged as a sealing element on a carrier, which is also referred to as a brush seal. The wire pieces or fibers each extend angled away from the carrier, with their free ends they can then rest against the component to be sealed, for example to seal the shaft.

Presentation of the invention

The present invention is based on the technical problem of specifying a particularly advantageous method for producing a sealing device with a carrier seal.

This is achieved according to the invention with the method according to claim 1. In addition to the carrier seal, the sealing device has a housing which surrounds the carrier. During production, a first part of the housing is initially produced, on which the carrier seal is then positioned, for example placed on it. A second part of the housing is then produced, namely printed on the first part in a 3D printing process. When viewed in a sectional plane perpendicular to the longitudinal axis of the carrier, the first and the second part of the housing enclose the carrier with one another (the sealing arrangement preferably extends away from the carrier at an angle to the longitudinal axis), see below in detail.

By printing the second housing part, a one-piece housing can be realized as a result. To a certain extent, the second part of the housing is molded directly onto the first part; these are not separate, merely assembled individual parts. With a view to later use, this can help prevent leaks, for example. 3D printing, for example in small series, can also offer advantages in terms of costs and lead times.

Preferred refinements can be found in the dependent claims and the entire disclosure, wherein the representation of the features does not always differentiate in detail between process aspects and the sealing device produced; in any case, the disclosure is to be read implicitly with regard to all claim categories.

The housing surrounds the carrier, but the sealing element (e.g. wire pieces or fibers) protrudes from the housing. Viewed in the section plane mentioned, the housing parts therefore do not completely enclose the carrier, a gap remains for the sealing element (which preferably applies over the entire axial length, that is to say in all section planes perpendicular to the longitudinal axis). On the application side, the housing can also serve, in particular, to assemble the sealing device, for example the positive and / or non-positive fastening to another component of the turbomachine or the aircraft engine. In this regard, a flexibility that is created by the production in the 3D printing process can be advantageous, namely that the housing can be comparatively easily adapted to different geometrical framework conditions.

In a preferred embodiment, the first and the second part of the housing hold the carrier in a positive manner in all directions perpendicular to the longitudinal axis. When viewed in the section plane, for example, they then not only form a U-shape, but the carrier is held in this U-shape by an undercut. The positive connection thus holds the carrier in the housing in the direction in which the sealing element extends away from the carrier. In general, the carrier has its longest extension along the “longitudinal axis”, this lies centrally in the carrier and is partially enclosed by the housing.

According to a preferred embodiment, the first part of the housing is also produced using a 3D printing process, preferably using the same 3D printer as the second part of the housing. After the first housing part has been printed, the printing process is interrupted and the carrier seal is positioned, and the second housing part is then printed on. In general, 3D printing can also be a stereolithography process or selective laser sintering, for example.

In a preferred embodiment, a 3D printer with a print head is used. From this, the housing material is dispensed in a flowable form at a nozzle, the printhead being moved repeatedly over the part of the housing that has been produced to date. A working level is traversed with the printhead, for example in line form, and the printhead is then moved to a subsequent working level. The housing part or parts are built up level by level.

Applying the housing material with a printhead can be advantageous because the housing material can thus be selectively placed exactly where the housing is made. It is therefore not applied to a large area of the housing material, as in a powder bed process, for example, and then only solidified in some areas, but rather the housing material is only applied to the desired locations from the start (apart from any support structures). This can be of particular advantage in the present case because it can thus prevent contamination or damage to the sealing element, in particular the wire pieces or fibers of the carrier seal. Even smaller impurities or damaged areas could significantly impair the later functionality.

In a preferred embodiment, the housing material is brought into the flowable form by heating in the printhead, so that a heating device is integrated in it. In general, the housing material can be, for example, a plastic material, such as a thermoplastic such as B. PP or ABS. However, the housing can also be made from a metal, the flowable housing material then being, for example, a matrix material filled with metal particles, such as wax. In a subsequent temperature process, the metal can be compressed or baked.

In a preferred embodiment, an interface, at which the first and the second housing parts adjoin one another, lies parallel to a set of planes of the 3D printing method. This group of levels results from the working levels in which the housing material is applied one after the other. The interface preferably lies in the housing in such a way that a plane containing the interface passes through the carrier.

When viewed in the sectional plane perpendicular to the longitudinal axis of the carrier, the housing preferably forms a leg on at least one side of the sealing element, which limits a deflectability of the sealing element. In use, the sealing element can then be pressed against this leg due to a pressure difference. Limiting the deflection can improve the sealing function. The housing preferably also forms a leg on the other side of the sealing element (this can, for example, shield the sealing element against turbulent flow).

According to a preferred embodiment, the housing itself is not rotationally symmetrical, in spite of a rotational symmetry of the carrier seal. In particular in the case of the preferred application in a turbomachine or an aircraft engine, the carrier can be closed in a ring, its axis of rotation then typically coinciding with the longitudinal axis of the turbomachine or the axis of rotation of the rotors. The housing is nonetheless non-rotationally symmetrical, at least in segments, it can have, for example, geometric features such as recesses / projections for assembly, as described above. These can be integrated particularly well with the 3D printing process.

In a preferred embodiment, the carrier seal is a single carrier seal, that is to say the sealing element extends away from the carrier towards a free end. Such a structure can be used in particular in the sealing of components which are moved relative to one another, the free end of the sealing element sweeps along the component surface.

In a preferred embodiment, the carrier seal is a brush seal, ie pieces of wire or fibers extending away from the carrier form the sealing element. The wire pieces or fibers preferably each extend to a free end (single brush seal). The pieces of wire can be provided, for example, from a thin wire with a diameter in the submillimeter range (for example between 0.04 mm and 0.4 mm). The fibers can, for example, be aramid fibers which, for. B. can have a diameter of 0.012 mm.

According to a preferred embodiment, the carrier has a core and a clamping body. The pieces of wire or fibers are laid around this core, they are fixed to it with the clamping body. A longitudinally slotted tube can be provided as the clamping body, for example, which is bent during production and squeezed around the core together with the wire pieces or fibers placed around it. A thick wire can preferably be provided as the core, for example with a diameter of at least 1 mm (with a possible upper limit of at most 2 mm). The longitudinal axis of the carrier then coincides with the central axis of the thick wire.

The invention also relates to a sealing device produced according to the present disclosure, the housing of which is at least partially, preferably overall, a 3D printed part. The housing is printed around the carrier of the double carrier seal in such a way that it partially surrounds it.

Furthermore, the invention also relates to the use of such a sealing device for sealing in a turbomachine, in particular an aircraft engine. Components that are moved relative to one another are preferably sealed against one another with the sealing device.

Brief description of the drawings

The invention is explained in more detail below on the basis of an exemplary embodiment, the individual features within the framework of the subordinate claims also being essential to the invention in other combinations and furthermore not being distinguished in detail between the different claim categories.

• 1 ein Triebwerk in einem schematischen Axialschnitt;
• 2 eine erfindungsgemäße Dichtungsvorrichtung in einem zu ihrer Längsachse senkrechten Schnitt;
• 3 einen Zwischenschritt in der Herstellung der Dichtungsvorrichtung gemäß 2;
• 4 auf die Situation gemäß 3 folgend einen weiteren Zwischenschritt der Herstellung.

In detail shows

• 1 an engine in a schematic axial section;
• 2nd a sealing device according to the invention in a section perpendicular to its longitudinal axis;
• 3rd an intermediate step in the manufacture of the sealing device according to 2nd ;
• 4th according to the situation 3rd following a further intermediate step in manufacturing.

Preferred embodiment of the invention

1 shows a turbomachine 1 in an axial section, specifically a turbofan engine. The turbomachine is functionally structured 1 in compressor 1.1 , Combustion chamber 1.2 and turbine 1.3 . Both the compressor 1.1 as well as the turbine 1.3 are each made up of several stages, each stage is usually composed of a guide and a rotor blade ring. The rotor blades rotate around a longitudinal axis during operation 2nd the turbomachine 1 . You are on waves 3.1 , 3.2 arranged. In the seal against the waves 3.1 , 3.2 is a possible area of application for a sealing device in question.

2nd shows such a sealing device 20th . This has a carrier seal 21st and a housing 22 on. The carrier seal 21st is from a carrier 23 built on which a sealing element 24th , namely pieces of wire or fibers are arranged. Specifically, the carrier points 23 a core 25th around which the pieces of wire or fibers are laid. You will be reminded of it by a sprag 26 held, in the present case a longitudinally slotted tube, around the core 25th together with pieces of wire or fibers. The cutting plane according to 2nd is perpendicular to a longitudinal axis 27th of the carrier 23 . With their free ends, the pieces of wire or fibers lay against the surface to be sealed 28 on.

3rd illustrates an intermediate step in the manufacture of the sealing device 20th . It was already a first part 22.1 of the housing 22 manufactured in a 3D printing process (see below). In this first part 22.1 will, as in 3rd illustrated the carrier seal 23 inserted. This was previously made conventionally.

4th illustrated according to the situation 3rd following like a second part 22.2 of the housing 22 is printed in a 3-D printing process (at an interface 22.3 starting). From a printhead 40 of a 3D printer 41 becomes the housing material 42 issued in flowable form. The printhead 40 is in one level 43.1 moved in line form over the resulting component, the housing material 42 is applied where the second housing part 22.2 should arise. Then the printhead 40 to the level above 43.2 moved (and then to the levels 43.3 , 43.4 ). The case is present 22 provided from a plastic material. With a view to overhangs, support structures (not shown) can also be printed in practice, which are then removed again.

Reference symbol list

1

Fluid machine

1.1

compressor

1.2

Combustion chamber

1.3

turbine

2nd

Longitudinal axis

3.1.3.2

waves

20th

Sealing device

21st

Carrier seal

22

casing

22.1

First part

22.2

Second part

22.3

Interface

23

carrier

24th

Sealing element (wire pieces / fibers)

25th

core

26

Sprags

28

surface

40

Printhead

41

3D printer

42

Housing material

43.1-43.4

Levels

Claims (15)

Method of manufacturing a sealing device (20), which has a carrier seal (21) with a carrier (23) and a sealing element (24), and a housing (22), the sealing element (24) extending on the carrier (23) and the housing (22) the carrier ( 23) includes the method by which - a first part (22.1) of the housing (22) is produced, - the carrier seal (21) with the carrier (23) is then positioned on the first part (22.1) of the housing (22), - and then in a 3D printing process, a second part (22.2) of the housing (22) is printed on the first part (22.1), the first and the second part (22.1, 22.2) of the housing (22) together holding the carrier ( 23) partially enclose viewed in a sectional plane perpendicular to its longitudinal axis (27). Procedure according to Claim 1 , in which the first and the second part (22.1, 22.2) of the housing (22) hold the carrier (23) in a positive manner in all directions perpendicular to the longitudinal axis (27) of the carrier (23). Procedure according to Claim 1 or 2nd , in which the first part (22.1) of the housing (22) is also produced in a 3D printing process. Procedure according to Claim 3 , in which the first and the second part (22.1, 22.2) of the housing (22) are produced with the same 3D printer (41). Method according to one of the preceding claims, in which a housing material (42), from which at least the second part (22.2) of the housing (22) is printed, is output in the 3D printing method in flowable form from a print head (40). Procedure according to Claim 5 , in which the housing material (42) is brought into the flowable form by a heating device in the print head (40). Method according to one of the preceding claims, in which an interface (22.3) between the first and the second part (22.1, 22.2) of the housing (22) lies parallel to a set of planes (43.1-43.4), in which is printed in the 3D printing process becomes. Method according to one of the preceding claims, in which an interface (22.3) between the first and the second part (22.1, 22.2) of the housing (22) lies in a plane which passes through the carrier (23) of the carrier seal (21). Method according to one of the preceding claims, in which the housing (22), viewed in the sectional plane perpendicular to the longitudinal axis (27) of the carrier (23), forms a leg on at least one side of the sealing element (24) which deflects the sealing element (24 ) limited. Method according to one of the preceding claims, in which the carrier (23) of the carrier seal (21) is rotationally symmetrical about an axis of rotation, but the housing (22) is asymmetrical with respect to this axis of rotation, at least in segments. Method according to one of the preceding claims, in which the carrier seal (21) is a single carrier seal (21), that is to say the sealing element (24) extends away from the carrier (23) towards a free end. Method according to one of the preceding claims, in which the carrier seal (21) is a brush seal, namely pieces of wire or fibers arranged on the carrier (23) form the sealing element (24). Procedure according to Claim 12 , in which the carrier (23) has a core (25) and a clamping body (26), the wire pieces or fibers being laid around the core (25) and being held thereon by the clamping body (26). Sealing device (20) with a carrier seal (21) and a housing (22), wherein the carrier seal (21) has a carrier (23) and a sealing element (24), wherein the sealing element (24) extends at an angle to a longitudinal axis (27) of the carrier (23) and the housing (22) surrounds the carrier (23), and wherein the sealing device (20) is produced in a method according to one of the preceding claims, that is to say the housing (22) is at least partially a 3D printed part which partially views the carrier (23) in a sectional plane perpendicular to the longitudinal axis (27) encloses. Use of a sealing device (20) after Claim 14 for sealing in a turbomachine (1), in particular an aircraft engine.

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