DE102020211755A1 - Bearing device for a turbomachine - Google Patents

Abstract

The invention relates to a bearing device (10) for a turbomachine, in particular for accommodating at least one roller bearing (7) for supporting a rotor (8). The bearing device (1, 10) has an annular mounting flange (2, 12) and a bearing seat (4, 14), which are connected to one another by a transition area (6, 16). The bearing seat (14) is arranged radially inside the mounting flange (12) and the transition area (16) has a bearing connection area (13), a flange connection area (15) and a winding area (17) connecting these connection areas (13, 15).

Description

The invention relates to a bearing device for a turbomachine, in particular for accommodating at least one roller bearing for supporting a rotor, the bearing device having an annular mounting flange and an annular bearing mount which are connected to one another by a transition area.

Bearings of turbomachines are often held by so-called squirrel cages, in which the mounting flange is connected to the bearing mount via spring bars. A ball or roller bearing, for example, is attached directly or indirectly to the bearing mount. The spring rods, which form the transition area between the mounting flange and the bearing mount, are dimensioned and designed according to the load cases that occur. The transition area must in particular prevent an offset between the mounting flange and the bearing mount in the radial direction and a tilting of the bearing mount relative to the axis. In the case of a bearing cage, the rigidity of the transition area is primarily determined by the number, the cross-sections and the length of the spring rods, with the length of the struts having a decisive influence on the rigidity. The radial displacement and tilting depend on each other via the geometry of the struts (round or square). High loads lead to stress peaks at the transitions from the struts to the bearing mount or to the mounting flange. Accordingly, such a design also restricts the minimum overall length of the bearing cage and thus also of the bearing device when there is a high load. Since the length of the transition area locally defines the length of the engine, shortening the transition area allows the entire turbomachine to be shortened and thus a large weight saving.

Proceeding from this, it is an object of the present invention to propose an improved bearing device for a turbomachine. According to the invention, this is achieved by the teaching of the independent claim. Advantageous developments of the invention are the subject matter of the dependent claims.

To solve the problem, a bearing device for a turbomachine is proposed, which serves in particular to accommodate at least one roller bearing for supporting a rotor of the turbomachine. The bearing device has an annular mounting flange and a bearing seat which are connected to one another by a transition area. The bearing seat is arranged radially inside the mounting flange. The transition area has a bearing connection area extending away from the bearing receptacle and a flange connection area extending away from the mounting flange and a winding area connecting these connection areas. The bearing device also has a support bearing, which is arranged on the mounting flange and/or on the flange connection area extending from the mounting flange in such a way that a radial gap remains between the support bearing and the bearing mount and the bearing mount can be supported on the support bearing when the gap is overcome by radial deflection .

The transition area has a bearing connection area that extends away from the bearing receptacle and a flange connection area that extends away from the mounting flange and a winding area connecting these connection areas, with the individual areas following one another in particular without a transition. The connection areas and the winding area connecting them form, in particular, a thin-walled rotary body which is connected to the mounting flange at one end and to the bearing mount at the other end. The winding area has at least one curvature, which contributes to the deflectability of the transition area in the radial direction, in particular through a suitable geometry, the wall thickness or suitable material properties, in particular with regard to the modulus of elasticity. The winding area can also have at least one change in direction (inversion), so that the transition area has a double-walled cross-section, at least in sections.

The bearing device has a support bearing arranged on the mounting flange and/or on the flange connection area extending from the mounting flange, in particular rotating symmetrically. The inner radius of the support bearing is larger than the outer radius of the bearing mount, so that a radial gap remains between the support bearing and the bearing mount. The gap is dimensioned in such a way that the bearing mount can move within the gap during the rotation of the engine shaft in the event of relatively small imbalances or relatively small deflection of the engine shaft, without contacting the support bearing. The load absorbed by the bearing mount is guided over the transition area to the mounting flange. In the case of a particularly large radial deflection of the engine shaft or the bearing mount, which overcomes the gap, the load mount is supported on the support bearing, whereby the load absorbed by the bearing mount is guided directly via the support bearing to the mounting flange. Here, the gap between the bearing mount and the support bearing is over bridges. The direct load path, bypassing the transition area, results in an upward damping limitation with a corresponding deflection of the bearing mount.

The proposed solution allows a compromise in the design of the transition area between a defined stiffness and deflectability in connection with a low tilting tendency to optimize the length of the transition area, whereby in particular a shortening of the engine and thus large weight savings can be achieved.

The transition area is in particular designed to be rotationally symmetrical. The transition area has the same mechanical properties in all directions radially to the axis of rotation, in particular with regard to the rigidity and the displaceability of the bearing mount.

In one embodiment of the bearing device, the bearing seat is arranged axially in the area of the mounting flange. With a radial deflection that overcomes the gap between the bearing mount and the support bearing, a load can be transferred directly to the mounting flange or to the flange connection area adjoining it. In this case, the load transfer is bridged, bypassing the transition area. In this way, comparatively large radial forces can be transmitted from the turbine shaft to the mounting flange and thus to the engine casing.

In particular, the axial end of the bearing seat can be offset relative to the end face of the mounting flange. In this case, the axial end of the bearing mount can be axially further removed from the winding region than the end face of the mounting flange, so that the bearing mount extends beyond the end face of the mounting flange. Likewise, the axial end of the bearing seat can be arranged axially closer to the winding area than the end face of the mounting flange, so that the bearing seat is arranged axially inside the bearing device. Depending on the axial offset of the mounting flange and the bearing mount, the position of the support bearing for transmitting the forces in the event of a radial deflection of the engine shaft relative to the mounting flange is determined.

In one embodiment of the bearing device, the flange connection area extends essentially axially away from the mounting flange and/or the bearing connection area extends essentially axially away from the bearing mount. The term "substantially" is intended to make it clear that an extent which, in addition to the axial portion, also has a smaller radial portion should be included. A substantially axial extension away from the mounting flange or from the barrel mount enables a more space-saving connection of the transition area to the mounting flange or to the bearing mount compared to a radial or essentially radial extent and thus an overall more compact design of the transition area.

In one embodiment of the bearing device, the flange connection area and the bearing connection area extend in the same direction, essentially axially away from the bearing seat or from the mounting flange. In this embodiment, the flange connection area and the bearing connection area run coaxially to one another at least in sections, with the bearing connection area being arranged radially inside the flange connection area. Such an embodiment enables a comparatively long load path between the bearing mount and the mounting flange and thus an elastic configuration of the transition area.

In one embodiment of the bearing device, the winding region has at least one curvature pointing outwards in cross section. Such a design enables a compact and elastic design of the transition area.

In one embodiment of the bearing device, the winding area has a plurality of curvatures, in particular in opposite directions, in cross section. The rigidity of the transition area can be adapted in accordance with the desired load transfer requirements, in particular via the arrangement, number and size of curvatures. The properties of the transition area with regard to the load transfer can also be adapted by a suitable selection of the wall thickness in the area of one or more curvatures.

In one embodiment of the bearing device, the transition region is arcuate in cross section and in particular has the shape of a hairpin. Such a configuration has a compact structure with good load transfer and rigidity of the transition area at the same time. In particular, a significant shortening of the transition area can be achieved with a lower tendency to tilt compared to previously known designs of the transition area.

In one embodiment of the bearing device, the transition area has one or more recesses. In an embodiment with a plurality of recesses, these can be arranged at equal distances from one another in the circumferential direction be. Such a recess has, in particular, an axial alignment and thus follows the load transmission path in the transition region. A recess can extend in one or over one or more sections or areas of the transition area, or also over the entire length of the transition area. In this case, a plurality of recesses can also be provided distributed over the transition area. In particular, a multiplicity of recesses spaced evenly apart from one another can be provided, so that the areas between the recesses form struts in the manner of a bearing cage. The rigidity of the struts is also dependent on the geometry of the recesses or the struts and the design of the transition to or the connection to the adjacent area or to the bearing mount or to the mounting flange. In this way, the weight and rigidity of the transition area can be optimized.

In one embodiment of the bearing device, the support bearing is designed on the inner circumference and/or the bearing seat on the outer circumference to form a squeeze film. Such a squeeze film is usually formed by a film of lubricant, which is used to dampen a bearing that forms between the support bearing and the bearing receptacle when the bearing receptacle is sufficiently radially deflected. In particular, vibrations of the engine shaft mounted in the bearing mount are damped. Furthermore, the squeeze film also serves to lubricate and cool the bearing point that is formed. The at least one section on the inner circumference of the support bearing and/or the at least one section on the outer circumference of the bearing receptacle have a surface quality that is suitable for forming a squeeze film, in particular circumferentially.

In one embodiment of the bearing device, at least one lubricant channel for supplying the squeeze film with lubricant is arranged in the support bearing. Lubricant is guided through such a lubricant channel from a lubricant supply device through the support bearing arranged on the mounting flange and/or on the flange connection area in order to form the lubricant film. In particular, the lubricant passage opens at least one position on the inner circumference of the support bearing. In particular, it is also possible for the lubricant channel to have a number of branches and/or openings, which are arranged in particular distributed around the circumference of the support bearing.

In one embodiment of the bearing device, it is manufactured using an additive manufacturing process. Additive manufacturing processes include, for example, laser sintering, selective laser sintering (SLS), electron beam sintering, electron beam melting (EBM), selective laser melting (SLM) or 3D printing, etc. The material to be added or applied is Processed powder form, for example as a powder made of metal or a metal alloy. In this case, the powder is applied in particular in layers to a substrate. Subsequently, the powder layer is solidified in a component area for forming the component using energy radiation, such as a laser beam and/or an electron beam. The next layer of powder is then applied and again selectively solidified by means of energy radiation until the component, in this case the storage facility, is completed. At least one lubricant channel for supplying the squeeze film with lubricant can also be formed by means of the generative manufacturing method.

In one embodiment of the bearing device, the support bearing is a separately manufactured component of the bearing device. In this design, the bearing device is constructed in two parts and the support bearing is subsequently mounted on the mounting flange and/or on the flange connection area. An advantage of this design is improved accessibility during manufacture of the two bearing surfaces arranged on the inner circumference of the support bearing and on the outer surface of the bearing seat, which are only separated from one another by the radial gap in the installed state.

• 1 eine dreidimensionale Darstellung einer im Stand der Technik bekannten Lagereinrichtung;
• 2 eine schematische Darstellung einer beispielhaften Lagereinrichtung;
• 3 eine Schnittdarstellung einer beispielhaften erfindungsgemäßen Lagereinrichtung; und
• 4 eine Schnittdarstellung einer weiteren beispielhaften erfindungsgemäßen Lagereinrichtung.

Further features, advantages and possible applications of the invention result from the following description in connection with the figures. It shows

• 1 a three-dimensional representation of a storage device known in the prior art;
• 2 a schematic representation of an exemplary storage facility;
• 3 a sectional view of an exemplary bearing device according to the invention; and
• 4 a sectional view of a further exemplary bearing device according to the invention.

1 shows a three-dimensional representation of a bearing device 1 known in the prior art for a turbomachine. The bearing device 1 has an annular mounting flange 2 and a bearing seat 4 which are connected to one another by a transition area 6 . The transition region 6 has a plurality of spring bars which are spaced evenly apart from one another 6a up. The bearing seat 4 has on its inner circumference 4a a bearing seat for receiving at least one roller bearing, not shown, for supporting a rotor of the turbomachine, also not shown. A so-called squeeze film can be formed on the outer circumference 4b of the bearing mount 4 to dampen the bearing.

2 shows a schematic representation of an exemplary bearing device 1 and its bearing points 3. A defined rigidity of this bearing device 1 is mainly set via the transition area 6, which occurs in the in 1 illustrated embodiment is formed by a spring cage. In particular during operation of the turbomachine, radially directed forces F1 act on the transition region 6 and lead to a radial displacement (shown in dashed lines) of the bearing mount 4 relative to the mounting flange 2 . The transition area 6 is designed in such a way that it counteracts a tilting (shown in dotted lines) of the bearing mount 4 relative to the axis A with the spring rods 6a. When designing the transition area 6, it is therefore necessary to reach a compromise between a defined rigidity and low tilting. The storage device 1 should also have the lowest possible weight.

3 shows a sectional view of an exemplary bearing device 10 according to the invention for a turbomachine. The bearing device 10 has an annular mounting flange 12 and a bearing receptacle 14 arranged radially inside the mounting flange 12 . On its inner circumference 14a, the bearing seat 14 has a bearing seat for accommodating at least one roller bearing 7 for supporting a rotor 8 of the turbomachine. The mounting flange 12 and the bearing mount 14 are connected to one another by a transition area 16 . The transition area 16 has a bearing connection area 15 extending away from the bearing receptacle 14 and a flange connection area 13 extending away from the mounting flange 12 and a winding area 17 connecting these connection areas, which in the embodiment shown as an example has an outward-pointing curvature in cross section. In the exemplary embodiment, the flange connection area 13 extends axially away from the mounting flange 12 and the bearing connection area 15 extends axially away from the bearing seat 14 . Correspondingly, the flange connection area 13 and the bearing connection area 15 extend in the same direction axially away from the bearing receptacle 14 or from the mounting flange 12 . The transition region 16 of the exemplary bearing device 10 is arcuate in cross section and has the shape of a hairpin. The bearing receptacle 14 of the exemplary bearing device 10 is arranged axially offset somewhat to the right in the illustration in the area of the mounting flange 12 .

The bearing device 10 also has a support bearing 19, which is arranged on the mounting flange 12 and, in the case of the exemplary bearing device 10, at least partially also on the flange connection area 13, such that a radial gap 20 remains between the support bearing 19 and the bearing mount 14 and the bearing mount 14 at a the gap 20 overcoming radial deflection on the support bearing 19 can be supported. A so-called squeeze film 22 for damping the bearing can be formed on the inner circumference 19a of the support bearing 19 and on the outer circumference 14b of the bearing receptacle 14 . The inner peripheral surface of the support bearing 19 and the outer peripheral surface of the bearing seat 14 are designed in such a way that a squeeze film 22 can be formed between the two elements. In particular, the two peripheral surfaces also have a surface quality that is suitable for forming a squeeze film 22 .

In the exemplary embodiment, the support bearing 19 is a separately manufactured component which is firmly connected to the mounting flange 12 or the flange connection area 13 of the bearing device 10 . A lubricant channel 18 for supplying lubricant to a squeeze film 22 arranged on the inner circumference 19a of the support bearing 19 is formed in the support bearing 19 . The lubricant channel 18 runs approximately from the end face of the mounting flange 12 through the support bearing 19 and opens out in the area of the surface of the inner circumference 19a of the support bearing 19. A lubricant guided through the lubricant channel 18 serves to form a squeeze film 22 between the support bearing 19 and of the bearing mount 14 in the event of a radial deflection of the bearing mount 14 that overcomes the gap 20. The bearing device 10 and the support bearing 19 can be produced, for example, using an additive manufacturing process. With this method, a bearing device 10 can be produced with a hairpin-shaped transition region 16, for example, which requires complex processing, for example by means of a machining process, due to the large volumes of material to be removed. In addition, a lubricant channel 18 can be formed in the bearing device 10 directly during the production of the support bearing 19 using a generative method.

4 shows a sectional view of a further exemplary bearing device 10 according to the invention. The bearing device 10 largely corresponds to that in 3 Bearing device 10 shown match, which is why the same elements with the same reference numerals are denoted. In the 4 The bearing device 10 shown is different from the bearing device 10 3 executed in one piece, correspondingly this is made integrally with the support bearing 19. In this embodiment, no attachment of the support bearing 19 in the area of the mounting flange 12 and/or on the flange connection area 13 is required. The area of the outer peripheral surface 14b of the bearing receptacle 14 and the area on the inner circumference 19a of the support bearing 19, which make contact when the bearing receptacle 14 is radially deflected sufficiently, are manufactured with a surface quality that is suitable for forming a particularly damping squeeze film 22 . At least one lubricant channel 18 is formed in the support bearing 19 for supplying a lubricant to these peripheral surfaces.

In addition, at the in 4 Several recesses 24 are arranged in the transition region 16 shown in the embodiment shown. The recesses 24 each break through the wall and have an elliptical shape. In the circumferential direction, the recesses 24 are evenly spaced from one another, so that the area in which the recesses 24 are arranged forms a type of bearing cage. Also the in 4 The bearing device 10 shown is particularly suitable for production using an additive manufacturing process, in which the recesses 24 and the lubricant channels 18 can be formed directly.

Reference List

1

storage facility

2

mounting flange

4

stock pick-up

4a

inner circumference of the bearing mount

4b

outer circumference of the bearing mount

6

transition area

6a

spring bar

7

roller bearing

8th

rotor

10

storage facility

12

mounting flange

13

flange connection area

14

stock pick-up

14a

inner circumference of the bearing mount

14b

outer circumference of the bearing mount

15

bearing connection area

16

transition area

17

winding range

18

lubricant channel

19

support bearing

19a

inner circumference of the support bearing

20

gap

22

squeeze film

24

recess

A

axis

F1

power

Claims (14)

Bearing device for a turbomachine, in particular for accommodating at least one roller bearing (7) for supporting a rotor (8), the bearing device (1, 10) having an annular mounting flange (2, 12) and a bearing mount (4, 14) which is a transition region (6, 16) are connected to one another, characterized in that: - the bearing mount (14) is arranged radially inside the mounting flange (12), - the transition region (16) has a bearing connection region ( 13) and a flange connection area (15) extending away from the mounting flange (12) and a winding area (17) connecting these connection areas (13, 15), and - a support bearing (19) which is attached to the mounting flange (12) and/or is arranged on the flange connection area (13) in such a way that a radial gap (20) remains between the support bearing (19) and the bearing mount (14) and the bearing mount (14) with a radial A deflection on the support bearing (19) can be supported. storage facility claim 1 , characterized in that the bearing seat (14) is arranged axially in the region of the mounting flange (12). Bearing device according to at least one of the preceding claims, characterized in that the flange connection area (13) extends essentially axially away from the mounting flange (12) and/or that the bearing connection area (15) extends essentially axially away from the bearing mount (14). storage facility claim 3 , characterized in that the flange connection area (13) and the bearing connection area (15) extend in the same direction essentially axially away from the bearing seat (14) or from the mounting flange (12). Bearing device according to at least one of the preceding claims, characterized in that the winding region (17) has at least one outwardly pointing curvature in cross section. Bearing device according to at least one of the preceding claims, characterized in that the winding area (17) has a plurality of curvatures in cross-section, in particular in opposite directions. Storage device according to at least one of the preceding claims, characterized in that the transition region (16) is arcuate in cross section and in particular has the shape of a hairpin. Storage device according to at least one of the preceding claims, characterized in that the transition region (16) has one or more recesses (24). storage facility claim 8 , characterized in that a plurality of recesses (24) are arranged at equal distances from one another in the circumferential direction. Bearing device according to at least one of the preceding claims, characterized in that the support bearing (19) is designed on the inner circumference (19a) to form a squeeze film (22). Bearing device according to at least one of the preceding claims, characterized in that the bearing receptacle (14) is designed on the outer circumference (14b) to form a squeeze film (22). storage facility claim 11 , characterized in that at least one lubricant channel (18) for supplying the squeeze film (22) with lubricant is arranged in the support bearing (19). Storage device according to at least one of the preceding claims, characterized in that it is produced using an additive manufacturing process. Bearing device according to at least one of the preceding claims, characterized in that the support bearing (19) is a separately manufactured component of the bearing device (10).

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