WO2017076584A1

WO2017076584A1 - Inner part for a turbomachine, turbomachine, and method for assembly

Info

Publication number: WO2017076584A1
Application number: PCT/EP2016/074284
Authority: WO
Inventors: Dieter Nass; Steffen Petri
Original assignee: Siemens Aktiengesellschaft
Priority date: 2015-11-05
Filing date: 2016-10-11
Publication date: 2017-05-11
Also published as: EP3165772A1

Abstract

The invention relates to an inner part (IP) of a turbomachine (TCO) for arranging in an outer case (OC) of the turbomachine (TCO), wherein the inner part (IP) has parts of a rotor (RO), which are provided for rotating during operation, and has elements of a stator (STA), which are designed as parts that are stationary during operation, wherein the rotor (RO) extends along an axis (X). The invention further relates to a turbomachine having the inner part and to a method for assembling the turbomachine. In the interest of simplified and damage-free assembly, inner part (IP), according to the invention, is designed in such a way that the rotor (RO) can be moved axially in relation to the stator from a first axial position (AP1) to a second axial position (AP2), wherein, in the first axial position (AP1), at at least two points spaced apart from each other axially, one support shoulder (SPS) each, extending in the circumferential direction (CD), is provided on the stator (STA) and on the rotor (RO), said support shoulders lying radially concentrically opposite each other, such that the rotor (RO) and the stator (STA) can be supported radially to each other by means of the support shoulders (SPS), wherein the support shoulders (SPS) are designed in such a way that, in the second axial position (AP2), the support shoulders (SPS) of the rotor (RO) and of the stator (STA) do not lie radially opposite each other.

Description

description

INTERIOR TO A TURBOMA, TURBOMA AND

METHOD OF ASSEMBLY

The invention relates to an inner part of a turbomachine for arrangement in an outer casing of the turbomachine, wherein the inner part for rotation in operation provided parts of a Ro ^¬ gate and formed as operating in operation parts of a stator, wherein the rotor extends along an axis. In addition, the invention relates to a Turboma ^¬ machine with the inner part and a method for mounting the turbomachine. Turbo compressor and method of the type defined above are already known from the patent application EP 2 045 472 AI. The method described in this patent application for mounting the turbomachine provides that an inner part of the tur ^¬ bomaschine comprising the rotor and a stator is inserted as a fully assembled module axially in a circumferentially unge ^¬ divides outer housing. The insertion opening into the cup-shaped outer housing, which can also be referred to as Topfge ^¬ housing is axially closed after reaching the end position of the inner part by means of a front-side cover.

In general, the axial end faces of the outer housing or frontal cover are each provided with a passage opening through which one shaft end of the rotor is axially led out of the outer housing. This shaft end can serve on the one hand for supporting the rotor and on the other hand for transmitting torques in front of or on the rotor of the turbomachine. In the region of the lead out of the shaft, a shaft seal is usually provided for sealing the gap between the opening contour and the shaft surface of the rotor or rotor. As part of the assembly, the shaft end is used on an axial side of the attachment of a so-called horsetail, which can also be referred to as an extension. The horsetail is essentially an axial extension of the rotor at an axial shaft end. This extension is used for the exhaust support of the inner part against the force of gravity in the Pha ^¬ se of the axial insertion into the pot-shaped outer housing, in which the inner part is a ^¬ is guided already partly in the outer housing, but the axial shaft end (without extension) containing the Introduces insertion movement, not yet protrudes from the axially frontal opening of the outer housing. In order to still intercept the inner part with respect to the weight force against the outer housing, so that the inner part can be inserted without damage ^¬ tion in the outer housing, this extension, which can be designed as a so-called horsetail (axially divisible), this vertically oriented load, so that the Inner housing largely without friction-increasing normal force acting on the outer housing can be inserted axially. It is also conceivable that only a partial relief of the contact surface between the outer housing and the inner part takes place and the normal ^¬ force between these two components by means of the horsetail is reduced only in the sense of a reduction in friction. The term "horsetail" results from the fact that the axial extension is separable in axial sections. This extension is used, the inner part so long as to be support alarm ^¬ zen until the spearheading shaft end emerges axially from the side opposite to ^¬ housing outlet or opening. After the exit, the shaft or the runner can be caught directly.

A disadvantage of the known method is that a special effort must be made to support the stator relative to the rotor of the inner part, so that it does not come to uncontrolled contacts and power transmissions between the rotor and the stator. Is the inner part by means of the horsetail at least on one axial side indirectly over the rotor in its entirety at least on one side supported or raised, loads at least a part of the Ge ^¬ weight of the stator of the inner part on the points of the rotor, where it comes against the stator as a result of small game first to a contacting pad. As a rule, there is a large number of shaft seals in each turbomachine, which can be designed, for example, as labyrinth seals. Regardless, it comes from the associated construction shaft seal type in the turbo engine in the area of the shaft seals usually most likely would be to Kontaktauf- because the radial plays are performed at least there in the interests of the least possible Sekundärströ ^¬ regulations.

At the same time, in particular at the wave you ^¬ obligations to components that are very sensitive, as example ^¬, in the case of the labyrinth seal often narrow Dichtbän- of - are used which are not suitable for transmitting large forces - and in two-dimensional view, sealing tips , Other components of the stator and Ro ^¬ tors are not usually designed to receive the large Ge ^¬ weight forces of the respective adjacent module. In order to avoid this uncontrolled partially punctiform at least lien-shaped support between these heavy components of the inner part, a fixation in the radial direction between the rotor and the stator is usually provided, which is suitable, the weight of the stator controlled relative to the rotor intercept. These precautions are complex and sometimes cumbersome in the assembly. The ^¬ se precautions must for example be designed so that on the introduction of the leading side of the inner part these precautions can be removed by the axially frontal opening of the outer housing. This need may require special precautions on the outer housing, which can be costly to manufacture and expensive to install and handle. The invention has set itself the task, the cost and effort in the context of the assembly for the purpose of supporting the stator relative to the rotor of the inner part of a turbomachine reduce machine and still not increase the risk of Beschädi ^¬ supply.

To achieve the object of the invention, an inner part of the type defined above is proposed with the additional features of claim 1. In addition, the invention proposes a turbomachine and a method for mounting the Turboma ^¬ machine according to the respective claims in this respect. The respective dependent claims contain advantageous developments of the invention.

Information such as radial, axial or tangential or circumferential direction always relate - unless stated otherwise - to an axis of the rotor which coincides with the axis of rotation of the rotor during operation. Components with identical function and essentially identical design are identically denoted and in the exemplary embodiments generally identically referenced. The inner part of a turbo-machine according to the terminology of the invention is a component which can generally include all parts of the rotor, but need not necessarily comprise. In addition, the inner part comprises some standing parts surrounded by the rotor, which are referred to here as a stator.

A preferred application of the invention relates to turbomachines designed as radial machines, in which a radial deflection takes place between the individual stages of the rotor in the stator. This radial deflection takes place by ^{¬ means of} a circumferentially extending channel surrounding the rotor. These deflections are collectively referred to as return stages and usually include so-called intermediate floors, which are at least formed in a dividing groove in the circumferential direction in a parting joint axially not teilba- ren. These intermediate floors arranged axially between the individual impellers of the rotor usually have shaft seals (the term "shaft seal" means in the accessory The term "shaft seal" means the sealing of a gap between a rotor and a stator, not just one

Casing outlet, but possibly also on other axial sections of the machine), which avoid a flow of a process fluid that is either compressed or expanded by the turbomachine to lower pressure conditions. The quality of this shaft seal directly influences the extent ungewoll ^¬ ter secondary flows, so that for example, the radial play ^¬ design of this shaft seal is a primary factor influencing the efficiency of such a turbomachine. In an axially collapsible rotor, it is also possible not to form the return stages or shelves in the circumferential direction and to gradually add the stator with the rotor to an inner part in a stacking work process ^{¬ together} .

The individual intermediate bottoms can be combined axially and radially by means of a shell divided over or in the circumferential direction axially over adjacent intermediate bottoms, so that the stator of the inner part forms a unit firmly joined together and attached to one another.

Alternatively, the individual intermediate floors may be fastened to one another in their part-joint plane by means of fastening elements and be combined axially relative to one another in another, if appropriate, manner. In any case, the inner part has an at least provisionally firmly assembled stator, so that the inner part forms a transportable unit for itself. The rotor is therefore arranged in the inner part form ^¬ conclusively, because the wheels (this document be ^¬ uses the terms "impeller" and "wheels" synonym both individually and in compound terms) of the rotor in the return stages of the stator an axially unlimited Prevent mobility. Within the limits of the axial mobility, it is provided according to the invention that the stator is axially movable from a first axial position to a second axial position relative to the stator. In the first axial position, a support shoulder extending in the circumferential direction is respectively provided on the stator and on the rotor radially concentrically opposite at two axially spaced locations, so that the rotor and the stator can be supported radially relative to one another by means of this support shoulder. At least on the rotor, these support shoulders should be rotationally symmetrical, so that the support of the stator by means of the rotor relative to the weight of the stator is possible regardless of the circumferential position of the rotor. Particularly preferably, the support shoulder also extends rotationally symmetrically in the circumferential direction in the stator, so that, for example, it is also possible to raise the entire inner part while attaching the stop means to the stator, so that the rotor can be raised indirectly via the stator of the inner part.

Particularly preferably, the abutment shoulders on the rotor are each located on a hub-side wheel disc of a

Impeller. Here, the blades act on the wheel disc as stiffening ribs and prevent buckling of the wheel disc under the load.

Alternatively, the abutment shoulder can also be provided on a cover plate of the impeller, in which case the forces must be transmitted from the weight of the stator via Impellerschaufein between the wheel disc and the cover plate of the respective impeller. This must be taken into account when designing the blades.

Particularly preferably, the support shoulder is provided at each of the outermost radial end of the wheel disc or the cover plate, so that does not create a separate paragraph in example, the wheel disc additional axial space requirement. The axial displaceability from the first axial position into the second axial position of the rotor relative to the stator of the inner part is expediently also made possible by an axially wider ge ^¬ stalteten wheel side space, so that the wheel disc in the context of the axial displacement in the extended width of

Axially engages Radseitenraums, so that the Anlageschul ^¬ ter in the first axial position when engaged in the Radseitenraum wheel disc of the stator relative to the contact shoulder of the rotor is preferably located at the radially outer end of the wheel disc of the impeller. This procedure also has the advantage that in the case of a stepped cover labyrinth, this shaft seal provides sufficient axial play in the case of the wheel-disk-side displacement direction. Particularly preferably, the wheel disk in the region of the Anla ^¬ trained rotationally symmetric - convex in cross-section - be formed so that it over a part of the circumference ge ^¬ insignificant force-related elastic deformations of Rad ^¬ disc or the stator in the region of the respective investment shoulder presupposed comes to a substantially linear edition. In this case, line-shaped means that the extension of the support surface in the circumferential direction is longer than in the axial direction. Alternatively, the abutment shoulder also rotationally symmetrical conical - in cross section obliquely to the axis or axis of rotation - each be formed, so that the two abutment shoulder surfaces are oriented parallel to zueinan ^¬ axially parallel alignment of the stator and the rotor. The conical bevel should be here before ^¬ Trains t oriented such that the rotor relative to the stator at a contact pressure force is pressed perpendicularly to the axis in Rich ^¬ tung an axial stop of the slope of the cone, so that an uncontrolled sliding off of the system ^¬ shoulders together is excluded. An advantageous development of the invention provides that the axial relative position of the stator and the rotor of the In ^¬ nenteils each other by means of at least one Befestigungsele ^¬ mentes is fixable. For this it is possible that the axial Relative position on an axial side by means of a securing element in a boundary region between the stator and the rotor, which is accessible from the outside, is fixed to at least one circumferential position by means of the securing element. For this purpose, for example, the rotor or the shaft of the rotor of the fastening element can be radially ^¬ clamped, the fastener simultaneously contacted an axial reference surface of the stator, so that an axial movement at least unidirectional, preferably bidirectional nal between the rotor and the stator is blocked. A complete backup of the axial position can also follow by means of two such fasteners.

Preferably, the axial end faces of the outer housing or frontal cover are each provided with a passage opening, through which in each case a shaft end of the rotor can be axially guided out of the outer housing. This shaft end can serve on the one hand for permanent or transitional mounting of the rotor and on the other hand for transmitting torques in front of or on the rotor of the turbomachine.

The inventive method provides that initially the outer housing is provided. Subsequently, an axi ^¬ ale extension in the sense of the aforementioned horsetail to the rotor at a shaft end is mounted rigidly so that the inner part raised by the extension - or intercepted in terms of weight - can be. Here it is sufficient if the inner part can be lifted to ^{¬ at} least on one axial side. It is not necessary that the entire inner part can be raised as a free end of this axial extension. In any case, the connection between the extension and the shaft end must be rigid, so that the torques or bending moments arising from the transverse force can be transmitted to an axially spaced support of the extension. Thereafter, the inner part is inserted by means of the exten ^¬ tion in the outer housing, wherein the rotor to the stator of the inner part befin- in the first axial det. Here, it is advantageous if the axial extension or horsetail cites these insertion and ^¬ ser extension is axially supported outside by a front side axial hole of the outer housing, so that a normal force between the inner part and the outer housing currency ^¬ end of the insertion operation at least reduced becomes. After fully ^¬ constant insertion movement of the rotor relative to the stator of the inner part can be axially offset in the second axial position. This axial displacement of the rotor relative to the stator can take place with the aid of the horsetail, wherein the stator of the inner part in the outer housing, the rotor is relieved of the weight and the rotor maneuvered without this additional load in the second axial position ^¬ who can.

In the following the invention with reference to a specific embodiment with reference to drawings is closer ^{¬ written} . Show it:

Figure 1 shows a schematic longitudinal section through a turbomachine according to the invention during the axial insertion of the inner part in the

Outer casing

Figure 2 is a schematic representation of Aufla ^¬ shoulders between a rotor and a stator of an inner part in one

Longitudinal section on the wheel disc side,

FIG. 3 shows a detail of FIG. 2, where it is ^labeled III,

FIG. 4 shows a detail from FIG. 2, in which the rotor is in a second axial position relative to the stator;

Figures 5 to 7 are each a schematic representation of

Steps of the method according to the invention rens for mounting a device according to the invention

Turbomachine with an inner part according to the invention. The figures each show longitudinal sections in a schematic

Playback, wherein the cutting plane in each case along an axis X extends, which is identical to the axis of rotation of a rotor RO. Geometrical data usually refer to axis X unless otherwise stated. The description of the figures applies across all figures, unless reference is made to a specific figure.

Figure 1 shows part of a turbomachine TCO with an in ^¬ nenteil IP. The inner part IP is mounted in Figure 1 by means of an axial extension EXT to a shaft end of the rotor RO SHE in an outer casing OC is ^¬ leads in the axial direction. As can also be seen in FIGS. 6, 7, during operation of the turbomachine TCO, the inner part IP comprises parts of a rotor RO provided for rotation and elements of a stator STA which are designed as stationary parts during operation. The inner part ^¬ IP is a transportable unit itself, which be ^¬ vorzugt at the point of commissioning the Turbomaschi ^¬ ne TCO with the outer casing OC is assembled. The Au ^¬ ßengehäuse OC is formed as an undivided in the circumferential direction so-called pot-shaped housing. On at least one Axi ^¬ alseite the outer housing front side is provided with an axial opening so that the inner part IP can be inserted axially into the Außengehäu ^¬ se OC. On the inner part IP a lid is preferably COV axially on a shaft end SHE of ro tors RO slid and mounted there, so that this de ^¬ ckel COV posi ^¬ tioniert with the axial insertion of the inner part IP also for the purpose of attachment to the outer casing OC is. The rotor RO comprises a shaft SH and a plurality of impellers IMP or impeller shrunk onto the shaft. The stator STA comprises a plurality of impellers IMP formed between the individual impellers

Return stages BST, each having a fluidic return channel, the radially outward of the Impeller IMP deflected flow of a process fluid back to radially inward deflected. In a manner not shown, the return stages are equipped with aerodynamic guiding means, guide vanes for directing the flow of the process fluid. In one, as shown here, not axially separable, so built rotor, in which the wheels are shrunk onto a massive undivided shaft or otherwise be ^¬ strengthened, the return stages BST, which are also referred to as intermediate floors, provided with a parting line, the extends in a plane which is paral lel ^¬ substantially perpendicular to the axis X. to summarize the

Return stages BST is also provided with a parting groove holder CR (this holder may also be referred to as an inner housing) is provided, which secures the return stages BST in the desired axial and radial position to each other. Alternatively, the return stages BST are attached directly to each other, z-B. screwed together.

The individual stages of the turbomachine TCO are sealed to one another by means of at least one shaft seal SSL. In the embodiment, the shaft seal SSL seals Zvi ^¬ rule a cover disc of the impeller CW IMP and

Stator STA. The impeller IMP has, in addition to the cover plate on blades BL and a wheel HW. By means of the wheel disc HW, the impeller IMP is attached to the shaft SH of the rotor RO with a shaft-hub connection. The Be ^¬ fastening secures the impeller IMP in the axial, radial and tangential (against rotation) direction. The rotor RO is designed to be displaceable relative to the stator STA between a first axial position API and a second axial position AP2. For this purpose, a corresponding Axi ^¬ alspielauslegung the shaft seals SSL is provided and the impeller side WSR which firmly located an axial clearance between the impellers and the stator STA IMP are axially formed corresponding ready. In the first axial position API are located at two axially spaced locations (ALI, AL2) each one in the circumferential direction CD erstre- ckende support shoulder SPS respectively to the stator STA and to the rotor RO each radially concentrically opposite, so that the rotor RO and the stator STA by means of the support ^¬ shoulders SPS are supported radially to each other. In the second axial position SPS of the rotor RO and the stator STA no longer radially opposite one another, so that a sufficient radi ^¬ play for the operation under consideration of the rotor dynamics of the turbomachine TCO is given. In the case of the bearing of the support shoulders SPS of the rotor RO and the stator STA together, the rotor RO is in its operation substantially concentric with respect to its axis of rotation, possibly slightly ^eccentric , because there is a certain between the support shoulders SPS of the stator STA and the rotor RO Radial play ^{¬ be} attracted to the diameter there.

In Figures 5, 6 and 7 of the steps OF INVENTION ^¬ to the invention the method for mounting the turbomachine TCO are shown respectively. FIG. 5 shows the provision of the outer housing OC. FIG. 6 shows how, in the context of step b), an extension EXT has been attached axially to a shaft end SHE of the rotor RO of the inner part IP. The inner part IP has already been partially inserted axially into the outer housing OC, wherein the axial extension EXT leads the insertion movement axially. Step d) is shown schematically in FIG. 7, wherein FIGS. 3, 4 show in their detailed reproduction the radial abutment of the abutment shoulders SPS against each other in the first axial position API at the two axial points AL1, AL2. Figure 7 also shows that the cover COV of the outer casing OC is brought together with the inner part IP axially into its final position before it is fixed to the outer housing by means of OC buildin ^¬ actuating elements.

The shaft end SHE, which follows the axial movement is held by means of a support SUP ^¬ 'in the radial position. In addition, or alternatively, the inner part can also be supported by the stator STA by means of a support SUP '. Because it becomes complex in heavier designs to absorb the torque from the weight force over the shaft, As a rule, the support via the inner part IP is then preferred.

Claims

claims

1. Inner part (IP) of a turbomachine (TCO) for arrangement in an outer housing (OC) of the turbomachine (TCO), wherein the inner part (IP) for rotation in operation provide ^¬ ne parts of a rotor (RO) and as in operation Tei ^¬ le trained elements of a stator (STA), wherein the rotor (RO) extends along an axis (X),

characterized in that

the inner part (IP) is designed such that the gate is Ro ^¬ (RO) axially relative to the stator (STA) movable from a first axial position (API) in a second axial position (AP2),

wherein in the first axial position (API) at at least two axially spaced locations each extending in the circumferential direction (CD) support shoulder (SPS) respectively on the stator (STA) and on the rotor (RO) are each provided radially concentrically opposite, so in that the rotor (RO) and the stator (STA) can be supported radially relative to one another by means of the support shoulders (SPS), wherein the support shoulders (SPS) are designed such that in the second axial position (AP2) the support shoulders (SPS) of the rotor (RO) and the stator (STA) are not radially opposite one another.

2. inner part (IP) according to claim 1,

wherein the radially opposite pairings of support shoulders (SPS) have at least one support shoulder (SPS), which is convexly spherical or conical.

3. inner part (IP) according to claim 1,

wherein at least one support shoulder (SPS) on the rotor on a hub-side wheel disc (HW) or a cover plate (CW) of an impeller (IMP) is formed.

4. Turbomachine (TCO) with an inner part (IP) according to claim ^¬ 1,

comprising the outer housing (OC).

5. turbomachine (TCO) according to claim 2,

wherein the outer housing (OC) in the circumferential direction undivided with a parting line (SP) substantially perpendicular to Ach ^¬ se (X) is designed as a pot housing.

6. A method for assembling a turbomachine according Minim ^¬ least one of claims 4 or 5, characterized by the steps of:

a) providing the outer housing (OC),

b) applying an axial extension (EXT) to the ro tor (RO), the SHE) rigidly attached ^¬ is introduced (at a shaft end, so that the inner part (IP) by means of the Longer side ^¬ delay (EXT) against the weight of liftable is

c) axially inserting the inner part (IP) in the outer housing (by means of the prolongation Ver ^¬ OC), said rotor (RO) to the stator (STA) in the first axial position (API) is located,

d) Moving the rotor (RO) relative to the stator (STA) in the second axial position (AP2).