DE102010012779B3 - Method for manufacturing and/or repairing of e.g. blisk for aircraft engine, involves producing joint connection between hub element and rotor blade, where connection comprises joining zone with smaller cross-section thickness - Google Patents

Abstract

The method involves joining a rotor blade (12) with a hub element (10) e.g. rotor disk and/or a rotor ring. A joint connection (14) is produced between the hub element and the rotor blade, where the connection comprises a joining zone (16a), and another joining zone (16b) that comprises a smaller cross-section thickness. The joining zone is generated by a chemical and/or mechanical separating process after the joining process. An end region is joined with the hub element, and a component region is limited at the end region. Independent claims are also included for the following: (1) a method for improving testability of quality of joint connection between a hub element and rotor blade of an aircraft engine (2) an integral bladed rotor e.g. blisk and/or bling, for an aircraft engine.

Description

The invention relates to a method specified in the preamble of claim 1 for the manufacture and / or repair of an integrally bladed rotor. The invention further relates to a method for improving the testability of the quality of at least one joint connection between a hub element and at least one rotor blade of an integrally bladed rotor joined to the hub element, and an integrally bladed rotor of the type specified in the preamble of patent claim 15.

The so-called Bliskbauweise of rotors for turbomachinery, especially of rotors for aircraft engines, is becoming increasingly important both in the field of new parts manufacturing as well as in the field of repairs. A blisk (bladed disk) is a rotor construction in which both the disk-shaped hub element and the rotor blades are formed in one piece. This eliminates the otherwise necessary blade feet and disc grooves, so that the disc shape can be optimized weight saving for low edge load. Accordingly, rotors in which the rotor blades are made integral with a supporting ring are called bling (bladed ring). The advantages correspond to those of the blisk.

Such integrally bladed rotors can basically be milled from a block. At a cost-optimized production, however, high demands are made, which can only be met in the optimal interaction of machine dynamics, modern CNC control, optimal tool, clamping and cooling lubricant system.

For the production of such integral bladed rotors, friction welding and hot forging methods have therefore become increasingly important in recent years. In linear friction welding, for example, the hub member is firmly clamped while the individual rotor blades vibrate with a linear motion. By compressing the two joining partners generates frictional heat, causing the material in the contact area heated to forging temperature. At the same time, the joining partners are compressed so that a weld bead is created in the area of the joint connection. Alternatively, for example, inductive press welding methods, rotational friction welding methods or orbital friction welding methods can also be used for joining the hub element and rotor blades.

However, the joint between a hub element and a rotor blade is a weak point, which is difficult to test on the one hand, but with regard to their strength values (eg long-cycle fatigue, low-cycle fatigue, hot gas corrosion, creep). thermo-mechanical fatigue and the like) must meet the highest standards.

The object of the present invention is to enable a better verifiability of the quality of such joint connections.

The object is achieved by a method having the features of patent claim 1 for producing and / or repairing an integrally bladed rotor, by a method according to claim 11 for improving the testability of the quality of at least one joint connection between a hub member and at least one rotor blade joined to the hub member an integrally bladed rotor as well as an integrally bladed rotor having the features of claim 15. Advantageous embodiments with expedient developments of the invention are specified in the dependent claims, advantageous embodiments of the method for manufacturing and / or repair are to be regarded as advantageous embodiments of the method for improving the testability and the integrally bladed rotor.

A better verifiability of the quality of a joint connection between a hub element and at least one rotor blade of an integrally bladed rotor is inventively made possible by the fact that between the hub member and the rotor blade a joint connection is generated, which comprises a first joining zone, which has a smaller cross-sectional thickness compared to adjacent second joining zones , In other words, it is provided that the joining connection is formed in such a way that a first joining zone with a restricted cross section is formed in relation to the second joining zones adjoining the first joining zone on both sides. The joint connection thus has, at least in the region of the first joining zone, a depression with a restricted cross-sectional thickness. As a result, in contrast to the prior art, the integrally bladed rotor can be better tested for flaws in the area of the joint connection. In principle, the method can be used both for producing new parts and for repairing already existing rotors.

Further advantages result from the fact that a rotor blade is first used for joining, which has an allowance at least in its end region to be joined to the hub element, and that the first joining zone after joining, preferably by means of a chemical and / or mechanical separation process is generated. The restricted cross-section, ie the first joining zone, is in other words produced by a corresponding post-processing of the previously produced joint connection. In this case, the joint connection can be processed, for example, by adaptive milling, electrochemical removal or other suitable separation processes to produce the recessed first joining zone. It can be provided in principle that the rotor blade - apart from the end region to be joined - is designed as a precision or as Aufmassschaufel.

Alternatively, it has been shown to be advantageous if a rotor blade is used for joining, which comprises an end region to be joined to the hub element and a component region adjoining the end region, the end region having a smaller cross-sectional thickness than the component region and the component region having a desired dimension Rotor blade has an oversize. In this way, the first joining zone can be formed simultaneously with the joining connection, since the component region adjoining the end region has a larger cross-sectional thickness compared to the end region. In contrast to the previous exemplary embodiment, therefore, an additional method step for producing the first joining zone can be dispensed with. However, it should be emphasized that in principle, of course, an additional post-processing step can be performed, for example, to produce a predetermined geometry of the first joint zone.

In a further embodiment, it has proven to be advantageous if the joint connection is produced in such a way that the first joining zone has a reduced cross-sectional thickness of up to 1.5 mm, in particular between 0.5 mm and 1.0 mm, compared with the adjacent second joining zones and / or that the cross-sectional thickness of the first and the second joining zones has an oversize.

This allows a particularly reliable test for the presence of flaws, without significantly weakening the joint connection mechanically. By the joining zones of the joint connection have an allowance compared to a desired cross-sectional thickness of the joint, there is the possibility to optimize the geometry and surface properties of the joint in a targeted post-processing step.

In a further advantageous embodiment of the invention it is provided that the first joining zone is groove-shaped and / or formed such that it extends along a partial region of the joint connection and / or along the entire joint connection. As a result, a particularly high flexibility and adaptability to different material pairings and designs of the rotor is given.

In a further advantageous embodiment of the invention, it is provided that the rotor is rotated about its axis of rotation after generating the joint connection, wherein a rotational speed of the rotation is adjusted such that the rotor plastically deformed at least in the region of the first joint zone. In this way, any imperfections can be particularly well recognized, since they are increased or opened under the mechanical load. In addition, the strength of the joint connection is increased because it is stretched by the spinning of the rotor. Furthermore, by setting a corresponding rotational speed, a defined residual stress state of the rotor can be set. It can be provided that the rotational speed is adjusted such that the hub member is solidified. The speed required to plasticize the first joining zone is usually relatively small compared to a maximum allowable rotational speed of the rotor, but is particularly dependent on the geometry, weight and material of the rotor. The respective optimum speed can be determined individually, for example, simply by means of corresponding series tests with different rotational speeds. Alternatively or additionally, the respective optimum rotational speed can also be determined, for example, with the aid of the finite element method. Damage in the area of the rotor blade or on the hub element can be ruled out by the held oversize of the second joint zones. For example, a suitably designed spinning stand can be used to rotate the rotor. Such a spinning stand can easily be integrated into a production line, so that the process chain for producing the integrally bladed rotor can be kept very short.

It has proven to be advantageous if the rotor is rotated at a speed between 5000 U / min and 100,000 U / min, in particular at a speed between 10,000 rpm and 20,000 rpm. In particular, speeds of 10,000 rpm, 11,000 rpm, 12,000 rpm, 13,000 rpm, 14,000 rpm, 15,000 rpm, 16,000 rpm, 17,000 rpm, 18,000 rpm, 19,000 rpm / min or 20,000 rpm and corresponding intermediate speeds have been found to be advantageous for most rotors.

Further advantages arise when the rotor is heated to a temperature between 40 ° C and 900 ° C before and / or during rotation. As a result, thermal loads can be simulated, which can occur during operation in different turbomachines. In particular, temperatures of 100 ° C, 150 ° C, 200 ° C, 250 ° C, 300 ° C, 350 ° C, 400 ° C, 450 ° C, 500 ° C, 550 ° C, 600 ° C, 650 ° C, 700 ° C, 750 ° C, 800 ° C, 850 ° C or 900 ° C and corresponding intermediate temperatures have been found to be advantageous when the rotor is made of a high temperature resistant material such as a nickel or cobalt base alloy. In principle, it may also be provided that axial and / or radial temperature gradients are generated.

In a further embodiment, a particularly good test of the quality of the joint connection is made possible by determining a surface condition and / or a geometry of the rotor before and / or after turning, at least in the area of the joint connection. By checking the geometry before and after turning, errors can be detected very reliably. Alternatively or additionally, the joint connection can be irradiated, for example using an X-ray source, since flaws widen due to the tensile stress occurring during the rotation.

A particularly high quality of the rotor is achieved in a further embodiment in that the rotor is finished to produce a desired geometry. In this way, both a desired surface quality and a required dimensional stability of the rotor can be produced.

A further aspect of the invention relates to a method for improving the testability of the quality of at least one joining connection between a hub element, in particular a rotor disk and / or a rotor ring, and at least one rotor blade of an integrally bladed rotor, in particular a blisk and / or one joined to the hub element Blings for an aircraft engine, wherein at least the steps providing the rotor, wherein this in the region of the joint connection comprises a first joining zone, which opposite to the first joining zone adjacent second joining zones has a smaller cross-sectional thickness, and rotating the rotor about its axis of rotation, wherein a speed of Rotation is adjusted such that the rotor, at least in the region of its first joining zone plastically deformed, are performed. The resulting advantages can be found in the previous descriptions. The preferred embodiments and developments presented in connection with the method according to the invention for producing and / or repairing an integrally bladed rotor and their advantages apply correspondingly to the method according to the invention for improving the testability of the quality of at least one joint connection.

A further aspect of the invention relates to an integrally bladed rotor, in particular a blisk and / or a bling for an aircraft engine, with at least one rotor blade, which is joined to a hub element, in particular a rotor disk and / or a rotor ring. According to the invention, a better verifiability of the quality of such joint connections is made possible in that a joint connection between the hub element and the rotor blade comprises a first joint zone, which has a smaller cross-sectional thickness compared to adjacent second joint zones. In other words, it is provided that the joint connection is formed in such a way that a first joint zone is formed with a cross-section restricted in relation to the two adjacent joint zones. The joint connection thus has at least partially a recess. As a result, in contrast to the prior art, the integrally bladed rotor can be better tested for flaws in the area of the joint connection. The rotor according to the invention is obtainable for example by a method according to one of the preceding embodiments. Further advantages resulting therefrom can be found in the previous descriptions. The preferred embodiments and developments presented in connection with the method according to the invention for producing and / or repairing an integrally bladed rotor and their advantages apply correspondingly to the rotor according to the invention.

Further features of the invention will become apparent from the claims, the exemplary embodiments and with reference to the drawings. The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the exemplary embodiments can be used not only in the particular combination indicated, but also in other combinations or in isolation, without departing from the scope of the invention. Showing:

1 a schematic perspective view of a fan blade joined to a hub member;

2 a schematic and partial side view of an in 1 shown joint connection between the hub member and the rotor blade;

3 a schematic sectional view of the joint connection between the hub member and the rotor blade;

4 a schematic sectional view of the joint connection between the hub member and a rotor blade formed according to another embodiment;

5 a further schematic sectional view of the joint connection between the hub member and the rotor blade; and

6 a schematic diagram of a rotor which is rotated about an axis of rotation.

1 shows a schematic perspective view of one with a disc-shaped hub member 10 joined rotor blade 12 , Between the hub element 10 and the rotor blade 12 There is a joint created by means of a linear friction welding process 14 which is a first joining zone 16a includes. The first joining zone 16a has opposite to both ends adjacent second joining zones 16b a smaller cross-sectional thickness and extends along the entire joint connection 14 , The two ends of the first joining zone 16a adjacent second joining zones 16b are indicated by hatching.

2 shows a schematic and partial side view of the in 1 shown joint connection 14 between the hub element 10 and the rotor blade 12 , Here is an example of a fault 18 This was previously difficult to record in testing technology. The fault 18 forms a weak point leading to lower strength values of the finished rotor 20 (S. 6 ) can lead.

3 shows a schematic sectional view of the joint connection 14 between the hub element 10 and the rotor blade 12 , For creating the joint connection 14 became a rotor blade 12 used in her with the hub element 10 to be joined end 22 has shown an oversize. After joining, the first joining zone having the reduced cross-sectional thickness became 16a generated by a mechanical separation process. The groove-shaped first joining zone 16a has a reduced cross-sectional thickness of up to 1.0 mm compared to the adjacent second joining zones 16b on. The second joining zone 16b subsequent area 26 the rotor blade 12 also has an allowance to a desired nominal dimension, so that the rotor blade 12 represents a so-called Aufmassschaufel.

4 shows a schematic sectional view of the joint connection 14 between the hub element 10 and a rotor blade formed according to another embodiment 12 , For creating the joint connection 14 was in the present embodiment, a rotor blade 12 used one with the hub element 10 to be joined end 22 , as well as one at the end area 22 adjacent component area 24 included. The first end area 22 had a smaller cross-sectional thickness than the component area 24 on, whereas the component area 24 with respect to an indicated nominal contour S of the rotor blade 12 had an oversize. The to the component area 24 adjacent area 26 the rotor blade 12 is in contrast to the previous embodiment already formed with a desired nominal dimension, so that the rotor blade 12 with the exception of the component area 24 represents a precision bucket and can be used without further post-processing steps.

5 shows for further clarification, another schematic sectional view of the joint connection 14 between the hub element 10 and the rotor blade 12 , It is in the area of the joint connection 14 a Schweißwulst initially formed by the joining 28 recognizable, which is subsequently reworked by means of a separation process such that the first joint zone 16a is formed. As in 5 is recognizable, has the first joining zone 16a a reduced cross-sectional thickness over the adjacent joining zones 16b on. Compared to the nominal dimension S shown with dashed lines has the first joining zones 16a however, an oversize.

6 shows a schematic diagram of a designed as a blisk rotor 20 , which after the production of the individual joints 14 between the hub element 10 and the individual rotor blades 12 is rotated in accordance with arrow IV in any direction about a rotation axis D. For this purpose, the rotor 20 clamped in a spin booth (not shown). A speed of rotation is adjusted so that the rotor 20 at least in the area of the respective first joining zones 16a (not recognizable) plastically deformed. In the present case, a speed of about 17000 rpm is set for this purpose. This results in a particularly good testability of the joints 14 scored because of any flaws 18 be opened. In addition, the joining zones 16a . 16b stretched, so that a defined residual stress state can be adjusted with increased strength. The speed can in principle be set such that the hub member 10 is solidified with.

Through a geometry test of the joints 14 before and after turning can be said flaws 18 be detected particularly reliable. Alternatively or additionally, the flaws 18 be detected by X-ray or other radiating test methods with high reliability. The speed for plasticizing the joining zones 16a . 16b is relatively low compared to the maximum permissible speed of the rotor. Damage in the area of the rotor blades 12 and in the area of the hub element 10 can be excluded by the provisional measurement situation.

The for turning the rotor 20 used spinning stand can be easily integrated into a production line, so that the process chain for the production of the joined rotor 20 can be kept very short.

The parameter values given in the documents for the definition of process and measurement conditions for the characterization of specific properties of the subject invention are also within the scope of deviations - for example, due to measurement errors, system errors, Einwaagefehlern, DIN tolerances and the like - as included in the scope of the invention ,

Claims (15)

Method for producing and / or repairing an integrally bladed rotor ( 20 ), in particular a blisk and / or a bling for an aircraft engine, wherein at least one rotor blade ( 12 ) with a hub element ( 10 ), in particular a rotor disk and / or a rotor ring, is joined, characterized in that between the hub member ( 10 ) and the rotor blade ( 12 ) a joint connection ( 14 ) is generated, which a first joining zone ( 16a ) facing opposite second joining zones ( 16b ) has a smaller cross-sectional thickness. A method according to claim 1, characterized in that for joining a rotor blade ( 12 ) is used, which at least in their with hub element ( 10 ) end region to be joined ( 22 ) has an allowance, and that the first joining zone ( 16a ) after joining, preferably by means of a chemical and / or mechanical separation process. A method according to claim 1, characterized in that for joining a rotor blade ( 12 ) is used, which one with the hub member ( 10 ) end region to be joined ( 22 ) as well as one at the end area ( 22 ) adjacent component area ( 24 ), wherein the end region ( 22 ) has a smaller cross-sectional thickness than the component region ( 24 ) and the component area ( 24 ) with respect to a nominal dimension (S) of the rotor blade ( 12 ) has an oversize. Method according to one of claims 1 to 3, characterized in that the joint connection ( 14 ) is produced such that the first joining zone ( 16a ) a reduced by up to 1.5 mm, in particular between 0.5 mm and 1.0 mm, reduced cross-sectional thickness compared to the adjacent second joining zones ( 16b ) and / or that the cross-sectional thickness of the first and the second joint zones ( 16a . 16b ) has an oversize. Method according to one of claims 1 to 4, characterized in that the first joining zone ( 16a ) groove-shaped and / or is formed such that they along a portion of the joint connection ( 14 ) and / or along the entire joint connection ( 14 ). Method according to one of claims 1 to 5, characterized in that the rotor ( 20 ) after creating the joint connection ( 14 ) is rotated about its axis of rotation (D), wherein a rotational speed of the rotation is adjusted so that the rotor ( 20 ) at least in the region of the first joining zone ( 16a ) plastically deformed. Method according to claim 6, characterized in that the rotor ( 20 ) is rotated at a speed of between 5000 rpm and 100,000 rpm, in particular at a speed of between 10,000 rpm and 20,000 rpm. Method according to claim 6 or 7, characterized in that the rotor ( 20 ) is heated to a temperature between 40 ° C and 900 ° C before and / or during rotation. Method according to one of claims 6 to 8, characterized in that before and / or after rotation at least in the region of the joint connection ( 14 ) a surface finish and / or a geometry of the rotor ( 20 ) is determined. Method according to one of claims 1 to 9, characterized in that the rotor ( 20 ) is finished to produce a desired geometry. Method for improving the testability of the quality of at least one joining connection ( 14 ) between a hub element ( 10 ), in particular a rotor disk and / or a rotor ring, and at least one with the hub element ( 10 ) joined rotor blade ( 12 ) of an integrally bladed rotor ( 20 ), in particular a blisk and / or a bling for an aircraft engine, comprising the following steps: - providing the rotor ( 20 ), wherein this in the region of the joint ( 14 ) a first joining zone ( 16a ) which faces the first joining zone (FIG. 16a ) adjacent second joining zones ( 16b ) has a smaller cross-sectional thickness; and - turning the rotor ( 20 ) about its axis of rotation (D), wherein a rotational speed of the rotation is adjusted so that the rotor ( 20 ) at least in the region of its first joining zone ( 16a ) plastically deformed. Method according to claim 11, characterized in that the rotor ( 20 ) at a speed between 5000 rpm and 100,000 rpm, in particular at a speed of between 10,000 rpm and 20,000 rpm. Method according to claim 11 or 12, characterized in that the rotor ( 20 ) is heated to a temperature between 40 ° C and 900 ° C before and / or during rotation. Method according to one of claims 11 to 13, characterized in that before and / or after rotation at least in the region of the joint connection ( 14 ) a surface finish and / or a geometry of the rotor ( 20 ) is determined. Integrally bladed rotor ( 20 ), in particular blisk and / or bling for an aircraft engine, with at least one rotor blade ( 12 ) fitted with a hub element ( 10 ), in particular a rotor disk and / or a rotor ring, is joined, characterized in that a joint connection between the hub member ( 10 ) and the rotor blade ( 12 ) a first joining zone ( 16a ), which opposite opposite second joining zones ( 16b ) has a smaller cross-sectional thickness.

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