EP3192966B1 - Rotor for an axial turbomachine with axially aligned balancing flange and compressor - Google Patents

Description

The present invention relates to a rotor for a turbo machine according to the preamble of claim 1. The present invention also relates to a compressor according to claim 10.

Rotors for turbo machines have to meet a wide range of requirements and boundary conditions. For example, individual rotor base bodies or rotor stages should be able to be balanced in order to be able to operate unbalance-free, low-wear and low-maintenance during operation. The common balancing options include, for example, the assembly of individual balancing weights on rotor base bodies (or rotor disks). With these structural solutions, however, areas in rotor drums, i.e. in rotor inner areas of lined up rotor stages, can form in which bearing oil accumulations or other fluids collect due to their centrifugal force during operation of the rotor. This accumulation of bearing oil can lead to undesirable effects if the rotor is stopped and started again in the meantime. These effects include an escape of bearing oil (for example due to bearing seal leakage) or bearing oil mist into the main flow area of, for example, aircraft turbines and a subsequent unwanted or undesired transfer to so-called bleed air areas for cabin air entrances.

From the US patent U.S. 5,628,621 A a rotor for a turbo machine with a first and a second rotor base body is known, the first rotor base body having a connecting flange and a radially aligned balancing flange. The post-published European patent application EP 3 091 179 A1 describes a rotor assembly having a shaft-hub connection, the hub being connected to the downstream rotors. A balancing flange running in the axial direction is arranged on the hub. The subsequently published European patent application EP 3 091 178 A1 relates to a rotor for a turbomachine with a first and a second Rotor base body, the first rotor base body having a connecting flange with a balancing flange arranged radially on the outside of the first connecting flange.

One object of the present invention is to propose a rotor for a turbomachine which has suitable balancing options taking into account the problems mentioned. A further object of the present invention is to propose a compressor with a rotor according to the invention.

The object according to the invention is achieved by a rotor with the features of claim 1. It is also achieved by a compressor having the features of claim 10.

According to the invention, a rotor for a turbomachine is thus proposed, the rotor comprising at least one first rotor base body with a first connecting flange for connecting the first rotor base body to a second rotor base body. The first rotor base body is connected to at least one rotor blade and has an axially aligned balancing flange. The first connecting flange is materially connected to the balancing flange and the balancing flange is arranged radially on the inside of the first connecting flange.

A compressor according to the invention of a turbo machine has at least one rotor according to the invention. The compressor can be a high pressure compressor of an aircraft engine.

Advantageous further developments of the present invention are each the subject matter of subclaims and embodiments.

Exemplary embodiments according to the invention can have one or more of the features mentioned below.

In certain embodiments according to the invention, the axial flow machine is an axial gas turbine, for example an aircraft gas turbine. An axial flow machine can be referred to as an aircraft engine. An aircraft engine can have a compressor with several Compressor stages and a turbine with multiple turbine stages include. Compressor stages and turbine stages can each have several rotor stages and several stator stages.

The term “rotor” as used herein can include one or more rotor stages which, when the turbo machine is used as intended, rotate about an axis of rotation or axis of rotation of the turbo machine. A rotor or a rotor stage can be referred to as an impeller or comprise an impeller. A rotor or a rotor stage can comprise several rotor blades and a rotor base body. The rotor base body can be referred to as a rotor disk or rotor ring or comprise these.

A rotor can be installed and assembled in a turbo machine, in particular in an axial gas turbine.

The rotor blades of a rotor or an impeller can be positively connected by means of a releasable connection or integrally with the rotor base body. An integral connection is in particular a material or material connection. An integral connection can be produced using a generative manufacturing process. A rotor base body with blades integrally connected to the rotor base body can be referred to as an integrally bladed rotor. An integrally bladed rotor can be a so-called BLISK (Bladed Disk) or a BLING (Blade Ring).

The rotor base body can comprise rotor disks directed radially inward and / or axially oriented rotor arms. The rotor disks directed radially inward can be referred to as extensions or T-shaped extensions of the rotor blades.

The rotor can be designed or prepared for direct or indirect connection to a shaft of the turbomachine.

The term “rotor drum” as used herein can include sections of at least two axially interconnected basic rotor bodies. In particular, rotor arms can form a radial or cylindrical shape of the rotor drum. A rotor drum can likewise be formed over more than two rotor base bodies and optionally over several rotor arms and rotor disks.

The terms “rotor interior and rotor exterior” as used herein can designate the spaces inside and outside of rotor drums. The rotor interior can thus be delimited radially outward essentially by one or more rotor arms. In the axial direction, the rotor interior can essentially be delimited by rotor disks. The outer rotor space can be delimited radially inward essentially by one or more rotor arms. The rotor outer space essentially comprises the main flow channel of the turbo machine. Between a rotor arm and the main flow channel, for example, stator inner rings, with or without inlet seals, can also be arranged. The rotor interior and / or the rotor exterior can comprise several rotor stages.

Rotor base bodies arranged axially one behind the other can be connected to one another by means of rotor arms and / or rotor disks. The connection is in particular form-fitting and / or force-fitting.

The term “connecting flange” as used herein can mean a component for, in particular form-fitting and / or force-fitting, connecting or flanging a rotor base body or a rotor stage to a further rotor base body or to a further rotor stage. In some embodiments according to the invention, this connection of the connecting flange does not have a screw connection for connecting to one another. A positive connection of a connecting flange with, for example, a further connecting flange of an adjacent or axially adjoining basic rotor body can mean fitting into one another of radial and / or axial shoulders of the two connecting flanges. A positive connection can have a fit between the two components. A fit can be a clearance fit, a transition fit, or an interference fit. In the case of a press fit, an additional force fit can be added to the form fit.

The term "balancing flange" as used herein can be a shoulder, a web, an extension or the like in order to balance a component, in particular the component on which the balancing flange is fixed or of which the balancing flange is a section or to balance. In some embodiments according to the invention, the balancing flange can be used additionally or exclusively for balancing other, in particular adjacent, components. In particular, a balancing flange is not provided or designed for connection to a further component, that is to say not for flange-mounting to a further component.

In some embodiments according to the invention, the balancing flange is provided for receiving material for balancing. A material uptake can be a punctiform or Area-shaped application, for example a material-locking application by means of welding, soldering or gluing mean.

In certain embodiments according to the invention, the balancing flange is provided for removing material and for receiving material for balancing.

In some embodiments according to the invention, the first connecting flange is integrally connected to the balancing flange. An integral connection can be a one-piece connection. A one-piece connection can be produced, for example, by means of a casting process or by means of a generative manufacturing process.

In certain embodiments according to the invention, a radially inner contour of the first rotor base body in the area of the first connecting flange and the balancing flange is designed for the flow of fluids into a radially outer rotor space, in particular due to centrifugal forces, i.e. in an operating state with a rotary movement of the rotor. The fluid can also flow out of the rotor interior to the outside when the rotor or turbine is at a standstill, in particular after the rotor or turbine has been switched off. In the case of an aircraft turbine, this can lead to an oil smell in the cabin of the aircraft when the rotor is restarted or subsequently started. Escaping oil can be blown out immediately after a start process via ejection bores. In particular, the design of the contour does not have any cavities or storage areas for receiving fluid. The radially inner contour of the first rotor base body can be referred to as the boundary or border of a rotor drum (see definition above). A centrifugal force-induced outflow of fluids, in particular of bearing oils from rotor bearings arranged upstream and / or downstream of the rotor stages into the rotor outer space, can take place by means of radial bores or openings in the rotor drum. The radial bore (or a plurality of radial bores) can be arranged at a largest possible radius or maximum radius within the rotor drum. This can enable a complete or largely complete flow of fluids from the rotor interior into the rotor exterior. In particular, the radially inner contour of the first rotor base body in the area of the first connecting flange and the balancing flange does not have any cavities in which the fluid can collect or accumulate due to centrifugal forces. In other words, the radially inner contour of the first rotor base body is im The area of the first connecting flange and the balancing flange are designed to be barrier-free and flow-optimized.

In certain embodiments according to the invention, the axially arranged balancing flange is arranged radially on the inside of the first connecting flange. In other embodiments, the axially arranged balancing flange can be arranged radially on the outside of the first connecting flange.

In some embodiments according to the invention, the balancing flange has at least one area for removing material for balancing the rotor. The area for material removal can be on an axial end area, on a radial inner and / or outer area of the balancing flange. The area for material removal can extend over the entire circumference of the balancing flange or only affect individual areas over the circumference. For example, smaller or larger areas can be removed by cutting (e.g. by means of milling). For example, the balancing flange can be shortened and removed axially at the end, over the entire circumference or only in individual circumferential segments, and / or further areas on the radially inner and / or outer side can be removed for balancing. In particular, the ablated areas on the radially inner side of the balancing flange do not have any cavities that could hinder a possible outflow of fluids from the interior of the rotor. The circumferential segments for material removal can extend, for example, over 5 degrees, 10 degrees, 15 degrees, 20 degrees or other angular ranges.

In some embodiments according to the invention, in the assembled state of the first and second rotor base bodies, a radial gap is arranged between the balancing flange and the second rotor base body. The radial gap can simplify balancing by removing material from the balancing flange. Furthermore, the radial gap can simplify a form-fitting and / or force-fitting connection of the first connection flange to a second connection flange of the second rotor base body.

In certain embodiments according to the invention, the balancing flange and the first connecting flange are made from one material.

In certain embodiments according to the invention, the first rotor base body, the balancing flange and the first connecting flange are integrally connected to one another.

In some embodiments according to the invention, the first rotor base body has no balancing weights and / or screw passages for fixing balancing weights. In particular, in the area of the first connecting flange, the first rotor base body has no shoulders or flanges directed radially inward for fixing balancing weights.

In some embodiments according to the invention, the first rotor base body, the balancing flange and the first connecting flange are made from one material. A unit made from one material and comprising the first rotor base body, balancing flange and first connecting flange can be referred to as being in one piece.

Some or all of the embodiments according to the invention can have one, more or all of the advantages mentioned above and / or below.

By means of the rotor according to the invention, oil accumulations, for example bearing oil accumulations, in the interior of the rotor, that is to say inside the rotor drum, can advantageously be avoided or at least reduced. In particular, the arrangement of the balancing flange enables only small cavities or no cavities at all, in which oil can collect, to be created in the rotor drum. This can at least reduce the possibility of contamination of cabin air by bearing oil when the rotor is used in an aircraft engine.

Furthermore, by means of the rotor according to the invention, due to the avoidance of oil accumulations within the rotor drum in the rotor interior, oil coking can advantageously be prevented or at least reduced. Coking residues could have a negative influence, for example, on an imbalance in the rotor.

The balancing flange can advantageously be balanced as an individual part. This balancing can be referred to as individual part balancing. Individual part balancing enables balancing with an equivalent potential compared to alternative solutions according to the prior art, in which Individual balancing weights can be used, which are screwed on, flanged or shrunk on as additional parts by means of press fits.

By means of the rotor according to the invention and the axially aligned balancing flange, a flange cavity can advantageously be reduced to zero or to approximately zero compared to connecting flanges with separate balancing weights.

The rotor according to the invention can be used in turbines and / or compressors. Due to the design of a first rotor base body with an integral balancing flange, the installation space and the weight of the rotor and thus of the turbomachine can advantageously be optimized. This can result in economic advantages, for example through lower kerosene consumption and / or a compact design.

Fig. 1

zeigt einen Rotor nach dem Stand der Technik mit einem ersten Rotorgrundkörper, einem angeflanschten zweiten Rotorgrundkörper, angeschraubte Wuchtgewichte sowie ein Leitrad in Längsschnittdarstellung; und

Fig. 2

zeigt einen Detailausschnitt eines erfindungsgemäßen Rotors mit einem Verbindungsflansch zum Verbinden eines ersten Rotorgrundkörpers mit einem zweiten Rotorgrundkörper, sowie einen axial ausgerichteten Wuchtflansch.

The present invention is explained below by way of example with reference to the accompanying drawings, in which identical reference symbols designate identical or similar components. In each of the schematically simplified figures, the following applies:

Fig. 1

shows a rotor according to the prior art with a first rotor base body, a flanged second rotor base body, screwed-on balancing weights and a stator in a longitudinal sectional view; and

Fig. 2

shows a detail of a rotor according to the invention with a connecting flange for connecting a first rotor base body to a second rotor base body, as well as an axially aligned balancing flange.

Fig. 1 shows a rotor 100 according to the prior art with a first rotor base body 101, a flanged-on second rotor base body 103, riveted balancing weights 105 on the first rotor base body 101 and a stator 107 in a longitudinal sectional view.

The rotor 100 is flowed through in the axial direction a in the main flow direction 109. A plurality of rotor blades 111 arranged over the circumference u are fixed to the first rotor base body 101. Downstream (in the axial direction a) of the first rotor base body 101 and the rotor blades 111, the stator 107 is arranged, which is statically connected to the housing of the Turbo machine (in Fig. 1 not shown) is connected. An inner ring 115 is arranged radially inward on the guide vanes 113 of the guide wheel 107 arranged over the circumference u. Further downstream after the stator 107, the rotor blades 117 connected to the second rotor base body 103 are shown.

The first rotor base body 101 has a connection flange 119 and one (or more fastening flanges 121 distributed over the circumference u) for fastening balancing weights 105. The connecting flange 119 connects the first rotor base body 101 to the second rotor base body 103. The second rotor base body 103 has a rotor arm 123, at the axial, upstream end of which a further connecting flange 125 is arranged. The two connecting flanges 119, 125 are positive (the connecting flange 125 encloses or includes the connecting flange 119 on the axial and radial sides) and non-positive (the first rotor stage with the first rotor base body 101 and the rotor blades 111 is axially connected to the second rotor stage with the second rotor base body 103 and the rotor blades 117 clamped) connected to one another.

Furthermore, the rotor arm 123 has at least one radial bore 127. Further radial bores can be arranged over the circumference of the rotor arm 123. By means of this radial bore 127, fluids, for example bearing oils from rotor bearings arranged axially upstream and / or downstream, are to be transported from the rotor drum space 129, which can also be referred to as the rotor interior, into the rotor exterior 131. In the case of a rotating rotor 100, these fluids are thrown outward through the bore 127 due to centrifugal forces. The fluids can be transported further with the main flow from the rotor outer space 131. The radial bore 127 can be referred to as an oil throw-off bore.

In the prior art embodiment in Fig. 1 However, bearing oil can collect in so-called radial cavities 133 in the area of the fastening flange 121. This accumulated bearing oil can drip or flow off into the rotor outer space 129 and / or into housing cavities when the rotor 100 stops or comes to a standstill. When the turbine engine is started again or afterwards, this bearing oil is then sucked directly into the main flow channel by the flow. However, since the main flow is initially still low in this starting phase of the rotor 100, the bearing oil or When the turbo machine is used as an aircraft engine, at least parts of the bearing oil enter the so-called bleed air, which could enter the cabin air through radial openings in the housing. This could result in an oil smell in the cabin air, which could have further consequences and must be avoided at all costs.

A constructive avoidance of such cavities 133 is shown in FIG Fig. 2 illustrated and described by the rotor 100 according to the invention.

Fig. 2 shows a detailed section of a rotor 100 according to the invention with a connecting flange 119 for connecting a first rotor base body 101 to a further connecting flange 125 of a second rotor base body 103, as well as an axially aligned balancing flange 201.

The first rotor base body 101 has in comparison to Fig. 1 (State of the art) does not have a mounting flange with balancing weights. The balancing of the first rotor base body 101, and possibly the entire first rotor stage and other adjacent components of the rotor 100, however, takes place in this embodiment according to the invention by means of the axially aligned balancing flange 201. By means of the axial alignment of the balancing flange 201, one or more radial cavity, like them in Fig. 1 should be avoided. This allows the effects mentioned as they are to Fig. 1 have been described (accumulation of bearing oil in the cavities and a possible subsequent introduction of parts of this bearing oil or at least of bearing oil mist into the cabin air of aircraft) are advantageously prevented. In spite of this, balancing in this connection area of the two connection flanges 119, 125 can be carried out by means of the axially aligned balancing flange 201.

Balancing by means of the balancing flange 201 can be carried out by removing material at the axial end (in Fig. 2 at the right end) of the balancing flange 201. The necessary point or position for balancing can be analyzed and localized using suitable and known methods. Material can then be removed at the appropriate points, for example at selected angular positions over the circumference of the balancing flange 201, and thus the component (of the first rotor base body 101 or the first rotor stage as a whole) can be balanced.

The radial gap 203 is for an outflow of fluids from the rotor interior (see Fig. 1 ) unproblematic, since a fluid, for example bearing oil, can easily flow off to a radial opening without being blocked or collected in a cavity. Furthermore, the radial gap 203 can simplify the form-fitting and / or force-fitting connection of the two connecting flanges 119, 125.

The first rotor base body 101 is designed in an integral construction together with the first connecting flange 119 and the axial balancing flange 201. An integral construction means a material connection of these components, which are made in particular by means of the same material. With a generative process as a manufacturing option, different materials can also be used to manufacture an integral component. This can be advantageous, for example, to use an optimized material for removing material from the balancing flange 201.

The dividing line 205 can indicate a maximum possible axial material removal from the balancing flange 201. This can be necessary, for example, for the stability and component integrity of the first rotor base body 101.

A material removal on the balancing flange 201 can for example by means of cutting removal, z. B. by milling or drilling.

List of reference symbols

a

axial; Axial direction

r

Radial; Radial direction

u

Circumferential direction

100

rotor

101

first rotor body

103

second rotor body

105

Balancing weight

107

Idler

109

Main direction of flow

111

Blade

113

vane

115

vane

117

Inner ring

119

Connecting flange

121

Mounting flange

123

Rotor arm

125

further connection flange

127

radial bore

129

Rotor drum space; Rotor interior

131

Rotor outer space

133

radial cavities

200

inventive rotor

201

Balancing flange

203

radial gap

205

Dividing line

Claims (11)

1. A rotor (100) for an axial turbomachine, comprising at least one first rotor main body (101), wherein the first rotor main body (101) has a first connecting flange (119) for connecting the first rotor main body (101) to a second rotor main body (103), wherein the first rotor main body (101) is connected to at least one rotor blade (111) and has a balancing flange (201), and wherein the first connecting flange (119) is integrally bonded to the balancing flange (201) and the balancing flange (201) is arranged radially on the inside of the first connecting flange (119), characterized in that the balancing flange is axially aligned.
2. The rotor (100) according to claim 1, wherein, in the region of the first connecting flange (119) and the balancing flange (201), a radially inner contourof the first rotor main body (101) is designed to discharge fluids, in particular by centrifugal force, into an outer rotor space (131) that is arranged radially on the outside, the design having in particular no cavities (133) and reservoir regions for receiving fluid.
3. The rotor (100) according to one of the preceding claims, wherein the balancing flange (201) has at least one material-removal region for balancing.
4. The rotor (100) according to the preceding claim, wherein the material-removal region is arranged on the axial end region of the balancing flange (201).
5. The rotor (100) according to the preceding claim, wherein, when the first rotor main body (101) is in the assembled state with the second rotor main body (103), a radial gap is arranged between the balancing flange (201) and the second rotor main body (103).
6. The rotor (100) according to one of the preceding claims, wherein the balancing flange (201) and the first connecting flange (101) are made of one material.
7. The rotor (100) according to one of the preceding claims, wherein the first rotor main body (101), the balancing flange (201), and the first connecting flange (119) are integrally connected to one another.
8. The rotor (100) according to one of the preceding claims, wherein the first rotor main body (101) has no balancing weights (105) and/or screw openings for securing balancing weights (105).
9. The rotor (100) according to one of the preceding claims, wherein the first rotor main body (101), the balancing flange (201), and the first connecting flange (119) are made of one material.
10. A compressor of an axial flow machine, wherein the compressor has at least one rotor (100) according to one of claims 1 to 9.
11. The compressor according to claim 10, wherein the compressor is a high-pressure compressor of an aircraft engine.

Images