EP2997273A1

EP2997273A1 - Radial bearing

Info

Publication number: EP2997273A1
Application number: EP14727429.4A
Authority: EP
Inventors: Steffen KÄMMERER; Ralph Rudolph
Original assignee: Voith Patent GmbH
Current assignee: Voith Patent GmbH
Priority date: 2013-05-17
Filing date: 2014-05-14
Publication date: 2016-03-23
Also published as: US20160069384A1; WO2014184232A1; DE102014209062A1

Abstract

The invention relates to a radial bearing comprising a bearing housing (2) having a bearing bore (3) aligned along a bearing axis (LA) and having a number of tilting segments (5) for bearing a shaft (11), said segments being displaceable relative to the bearing housing (2) and being arranged circumferentially around the bearing axis (LA) at a distance from the latter. Each individual tilting segment (5) has an outer radial bearing surface (7) that can be supported on a supporting surface (8) of a pressure block (9) provided in the bearing housing (2). The invention is characterised in that the individual pressure block (9) is displaceably provided in a passage (12) extending radially through the bearing housing (2) and can move radially without being supported on the bearing housing (2), that said block is secured against rotation in the circumferential direction of the passage (12) by means of an anti-rotation element (15), and that at least part or all of the radial outer surface of the pressure block (9) lies on a common cylinder surface with the outer diameter of the bearing housing (2) or with a bushing surrounding said housing.

Description

radial bearings

The invention relates to a radial sliding bearing, in detail with the features of the preamble of claim 1. The invention further relates to a method for mounting a radial sliding bearing with support of the tilting segments on the bearing connection environment.

Radial plain bearings are available in various designs from the state of

Technology previously known. Representative is referred to below

References:

US Pat. No. 5,738,447

US Pat. No. 6,485,182 B

DE 601 10751 T2

DE 69503138 T2

EP 2 339 192 A1

DE 19514830 C2

GB 2285491 A

DE 602004003239 T2

EP 1859175 B1

CH 558 481 A.

The radial slide bearing comprises a bearing housing with a bearing bore oriented along a bearing axis and a plurality of tilting segments arranged circumferentially relative to the bearing housing for supporting a shaft, the individual tilting segments each having a radially outer bearing surface for supporting on a bearing surface on a bearing surface Bearing housing guided pressure block has. In this case, at least indirect support of tilting segments takes place on the bearing housing.

When used in turbo gearboxes, the properties of such bearings determine not only the geometry of the waves but also the rotor dynamic properties. In order to meet growing demands in use for supporting high-speed rotating shafts, a Radialkippsegmentlager is required, which can be operated with higher speed and bearing pressure, with less bearing clearance change in transient operation, low bearing deformation and with improved vibration characteristics. Previous storage concepts are characterized for at least partially meeting these requirements by a relatively complex structure, a complex production and / or space-consuming execution especially in the radial direction. The invention therefore an object of the invention to further develop a radial slide bearing of the type mentioned that this is even better meet the requirements in applications with very high peripheral speeds is characterized by a rigid segment support, also allows a radial space-saving training and in terms of manufacturing technology easy and is inexpensive to install.

The solution according to the invention is characterized by the features of claims 1 and 8. Advantageous embodiments are described in the subclaims.

A radial sliding bearing having a bearing housing with a bearing bore aligned along a bearing axis and a plurality of movable relative to the bearing housing and spaced from the bearing axis circumferentially about this arranged Kippsegmenten for supporting a shaft, wherein the single tilting pad each have a radially outer bearing surface for support on a support surface at a in the Bearing housing guided pressure block is, according to the invention thereby characterized in that the individual pressure block is guided free of support on the bearing housing in the radial direction movable in a radially extending through the bearing housing through hole and secured by a rotation against rotation in the circumferential direction of the through hole and the radial outer side of the pressure block at least partially, preferably completely with the outer diameter of the bearing housing or a sleeve enclosing this lies on a common cylinder surface. Bushings are particularly useful when, for example, the bearing housing is made of cast iron and is too soft for the application. When the bearing housing enclosing socket is, for example, an eccentric bushing. The inventively embodied radial plain bearing allows a stiff support of the tilting segments by the direct introduction of force into the bearing connection environment and is therefore also suitable for the storage of waves that rotate at very high speeds. Furthermore, the radial slide bearing according to the invention is structurally simple and easy to assemble.

The support of the bearing surface on the support surface can be done directly or with the interposition of other components. In this case, a lubricating film between the bearing surface and the support surface may be formed during operation of the radial sliding bearing.

For this purpose, the individual pressure block has at least one guide region for guiding in the bearing housing and in installation position at the radially inner end region a support region for forming the support surface, wherein the guide region is designed such that a clearance fit is provided between the outer circumference and the passage opening and the guide region in the radial direction has an extension which is dimensioned such that the support area is free of a bearing on the inner circumference of the bearing housing.

In an advantageous embodiment, the individual pressure block and / or the tilting segment is made of a material having a modulus of elasticity greater than 200 GPa, in particular greater than 250 GPa. The materials used are preferably technical ceramics. These allow a high radial stiffness while maintaining good thermal conductivity. Another advantage consists in the significantly lower coefficient of thermal expansion, which significantly reduce the risk of bearing clearance reductions due to temperature increases in transient operation.

For ease of manufacture, the formation of the individual passage opening in the bearing housing is formed in cross-section circular or oval.

In an advantageous development, a lubricant and / or coolant supply system is provided, which has at least one annular groove extending over at least a partial area in the circumferential direction around the bearing housing, which is arranged offset in the direction of the bearing axis in the direction of the bearing center or off-center wherein the annular groove is connected at least one radial bore in the housing with a gap formed between the individual tilting segments and the inner circumference of the bearing housing. The central annular groove design allows inclusion of the pressure blocks in their radially outer end region for this function.

The radial mobility of the pressure block within the passage opening and securing in the circumferential direction by means of a rotation, which is a form-locking with clearance on the guide portion of the pressure block effective and guided by the wall of the bearing housing fuse element, in particular comprises threaded pin. Due to its arrangement, this can already be used as an assembly aid during assembly of the bearing.

Radial plain bearings having at least 3 to 7 tilting segments, advantageously 4 to 5 tilting segments, are preferably used in the high-performance region for supporting purposes.

A method for assembling a radial plain bearing according to one of claims 1 to 7 is characterized by the following method steps:

- Providing a bearing housing with a bearing axis aligned along a bearing bore and a plurality of radially in relation to the bearing axis extending from the inner periphery to the outer circumference through holes;

Providing printing blocks with a support region and a guide region adjoining in the longitudinal direction of the printing block, which in

Circumferential direction is designed with respect to the passage opening with a clearance fit and an oversize relative to its extension in installation position in the longitudinal direction;

- providing tilting segments;

- Introduce the printing blocks in the through holes and fixing the

Pressure blocks with oversize on the outer circumference of the bearing housing relative to the installed state of the radial sliding bearing and the tilting segments by means of a calibration device on the bearing housing with adjustment of the nominal size of the bearing in H6 - tolerance

- Processing, in particular cylindrical grinding of the outer circumference except for

Outer circumference of the bearing housing.

The method allows a high dimensional stability of the bearing, since the adjustment can be made directly on the position of the printing blocks during assembly. Particularly advantageously, the pressure block can be clamped by means of a securing element of an already provided in the installed state of the bearing positive rotation against the passage opening.

In a further development, in the case of a central annular groove on the outer surface of the bearing housing during machining of the outer circumference, the annular groove for a lubricating and cooling system can be incorporated into the bearing housing and / or the pressure block.

The solution according to the invention will be explained below with reference to FIGS. 1 to 8.

FIG. 1 shows, in a simplified schematic representation, a perspective view of a radial sliding bearing 1 designed according to the invention. This comprises a bearing housing 2 with a bearing bore 3 extending along a longitudinal axis. The longitudinal axis simultaneously forms the bearing axis LA. To clarify the individual directions, a coordinate system is applied to the bearing axis LA here by way of example. The x-axis coincides with the bearing axis LA and describes the extent along this or the axial direction. The y-direction describes the extension in the radial direction.

In FIGS. 2 a and 2 b, a section of a radial sliding bearing 1, as shown in FIG. 1, is shown in an axially simplified schematic representation in an axial section. In this case, Figure 2a illustrates the arrangement of the components for supporting a shaft 1 1 under static stress. On the other hand, FIG. 2 b illustrates, on the basis of a view according to FIG. 2 a, the radial sliding bearing 1 in a state with tilting of the tilting segment 5. The bearing housing 2 may be formed by a cylindrical sleeve. Preferably, this consists of at least two half-shells 4.1 and 4.2. It is also conceivable embodiment not shown here of several partial shells, which are arranged adjacent to each other in the circumferential direction about the bearing axis LA and each other positively or positively connected. The radial sliding bearing 1 further comprises a plurality of movable relative to the bearing housing 2 and spaced from the longitudinal axis LA in the circumferential direction about these adjacent arranged tilting segments 5. The tilting pads 5 are used for storing a not shown in Figure 1, in the figures 2a, 2b with 1 designated wave about its axis. As viewed in the radial direction, starting from the bearing axis LA, these comprise in each case a radially inner support surface 6 and a radially outer bearing surface 7 with which the tilting segments 5 are supported at least indirectly on a connection component, in particular a support surface 8. The support surface 8 is formed on a pressure block 9, which is movably guided in the bearing housing 2 in the radial direction and secured in this against rotation. According to the invention, the pressure block 9 is designed and arranged such that, in the installation position of the radial plain bearing, it is free of direct support on the bearing housing 2 and terminates flush with the outer circumference 10 of the bearing housing 2 or a bush by the bearing housing 2 in the radial direction. The support of the forces thus takes place directly via the pressure block 9 in the bearing connection environment, ie the radial outer side 23 of the pressure block 9 is at least partially, preferably completely with the outer diameter dA of the bearing housing 2 on a common cylinder surface.

The guide of the pressure block 9 in the bearing housing 2 takes place in radially arranged in this and through the wall thickness, that is from the inner periphery 22 to the outer periphery 10 extending through holes 12. These through holes 12 are aligned in the radial direction. The displaceability of the pressure block 9 in the radial direction is guided by a clearance between the outer circumference 10 of the passage opening 12 Pressure block 9 and the inner circumference 22 of the through hole 12 realized. All you need is a simple clearance fit.

To realize the support function and design of the support surface 8, the pressure block 9 is characterized in terms of its execution by at least two areas, a first support portion 13 and a second guide portion 14. The function of the support portion 13 is the formation of the support surface 8. The function of the guide portion 14th exists in the guide function in the bearing housing 2. support area 13 and guide portion 14 are formed accordingly. With regard to its dimensioning, the support area 13 is made larger than the guide area 14 with respect to a center axis of the pressure block 9, which coincides with the center axis of the passage opening 12 in the installation position. In the case illustrated, the support surface 6 formed on the tilting segment 5 is convex. Accordingly, the support surface 8 is formed on the pressure block 9 concave in the circumferential direction around the shaft 1 1 viewed.

The concrete geometric design of the pressure block 9 can be done in various ways. Preferably, the passage opening 12 is circular or oval. The execution of the guide portion 14 of the pressure block 9 is complementary to circular or oval cross-section.

The pressure block 9 is preferably designed symmetrically with respect to a plane which is characterized by the center axis of the pressure block 9 and a perpendicular to this in the installed position in the axial direction. The support region 13 extends beyond the guide region 14 on both sides on the radially inner end region of the pressure block 9 in the installed position and is thus designed on both sides with a projection in the circumferential direction about the bearing axis LA. By analogy, this also applies to the extent in the axial direction. FIG. 2 b illustrates the support in the event of loading on the basis of a view according to FIG. 2 a. Visible here is a slight tilting of the tilting segment. 5 and thus the support surface 6 relative to the outer circumference of the shaft 1 to be supported. It can also be seen that the support region 13 is arranged at its side directed towards the guide region 14 at a distance from the inner circumference 22 of the bearing housing 2 and is thus free from direct support on the bearing housing 2. To prevent undesired rotation about an axis that describes the course of the passage opening 12 in the radial direction, an anti-rotation lock 15 is provided. With regard to the concrete embodiment of this there are a variety of ways. Representative reference is made to the embodiments in Figure 3a and 3b, which illustrates the function of the rotation 15 in a sectional plane, which is characterized by the bearing axis LA of the radial sliding bearing 1 and a perpendicular to this. In the simplest case, the anti-twist device 15 comprises fixing means in the form of threaded pins 16, which act on the outer circumference of the guide region 14 of the pressure block 9.

FIG. 3 a illustrates a detail of a view in an axial section plane. Recognizable are the bearing housing 2 in its axial direction of extent, the pressure block 9 after installation and the tilting segment 5, which is viewed in the radial direction in the axial and circumferential direction via a contact area on the support surface 8 of the pressure block 9 is supported. The rotation lock 15 is thereby positioned starting from the side surfaces 17 and 18 of the bearing housing 2 perpendicular to these. In the simplest case, a threaded pin 16 in the bearing housing 2, starting from a side surface 17 in a direction of the through hole 12 extending and opening into this threaded hole 20 is performed. The threaded bore 20 preferably extends orthogonally to the passage opening 12.

FIG. 3b shows the arrangement and design of the anti-twist device 15 in a section AA from FIG. 3a. The rotation 15 is effective on the outer circumference of the guide portion 14 of the pressure block 9. The threaded pin 16 of Anti-rotation 15 engages here in recesses on the outer circumference of the guide portion 14 and acts in particular during assembly with this frictionally under fixation of the pressure block 9 in its position within the passage opening 12 in the radial direction together.

FIG. 4 shows a perspective view of the arrangement of the individual components relative to one another and the fixing of the tilting segments 5 in the radial and circumferential direction with play via means 24 in the form of segment holding pins on the side windows 21 in a section from an axially perpendicular section through the radial sliding bearing 1. The function of the segment holding pins is in storage and transport in a backup of Kippsegmente 5 from falling out and allowing mobility in the radial and tangential or circumferential direction within a permissible game. For this purpose, the segment holding pins can either be firmly connected to the side windows and executed with play engaging in the tilting segments 5 or vice versa. The individual connection can be made non-positive or positive.

FIGS. 1 to 4 illustrate a particularly advantageous embodiment of a radial sliding bearing 1 with a lubricant and coolant supply system 25 associated therewith and not shown here in detail, which comprises an annular groove 19 arranged on the outer circumference of the bearing housing 2 in the circumferential direction about the longitudinal axis. The annular groove 19 is part of the coolant supply system. The annular groove 19 is arranged centrally relative to the axial extent of the radial sliding bearing 1. The annular groove 19 is arranged in the material of the bearing housing 2 and in the direction away from the shaft 1 1 and flush with the outer periphery 10 of the bearing housing 2 final radial outer side 23 of the pressure block 9. The annular groove 19 is connected via at least one connecting bore with a radial direction component in the bearing housing 2 with a space between the individual tilting segments 5. This connecting channel guides the lubricant into the region between the tilting segment 5 and the inner circumference 22 of the bearing housing 2 and the shaft surface 11. The lubricant or coolant used for the radial sliding bearing 1 according to the invention is usually oil. However, it is also conceivable to use water or another mixture. The function of the annular groove 19 is the oil supply of each, formed by a respective tilting segment 5 and the shaft to be supported 1 1 gap. Also conceivable are designs with grooves symmetrically to the bearing center on the outer diameter of the bearing housing 2 and thus outside of the pressure block 9. Furthermore, supply rails 26 are provided for lubricants or coolant, with the annular groove 19 are connected via the connecting channels, in particular oil channels in a conductive connection. The feed bars 26 and the oil passages are preferably inclined relative to a radial jet. The longitudinal axis of the oil passages can, for example, in an axially perpendicular section through the bearing axis arranged in the manner of secants to the limited by the lateral surface of the shaft 1 1 circle. The supply to the tilting segment 5 takes place on the side of the inlet edge 27. Under this edge of the tilting segment 5 is to be understood, which is first swept in the direction of rotation of the shaft 1 1 of the shaft 1 1. As the outlet edge 28 that edge of the same tilting segment 5 is referred to, which is the inlet edge 27 in the direction of rotation of the shaft 1 1 downstream. Due to the aforementioned tendency a particularly effective injection of the lubricant or coolant is guaranteed in the gap. According to a particularly advantageous embodiment, each of the feed bars 26 has threaded holes for screwing dosing screws. FIG. 5 shows an embodiment of the bearing housing 2. The passage openings 12, which are arranged centrally in the axial section, are provided in a complementary number to the number of tilting segments 5 to be supported and are arranged equidistant from one another in the circumferential direction adjacent to one another.

FIG. 6 shows a pressure block 9 as suitable for the embodiment of the radial plain bearing 1 according to FIGS. 1 to 4. FIGS. 7a to 7d illustrate, in a simplified schematic representation, the individual assembly steps of the manufacture of the radial plain bearing 1. According to FIG. 7a, the bearing housing 2 is provided with the through openings 12 extending in the radial direction from the inner to the outer circumference, for receiving the pressure blocks 9. FIG. 7a shows the bearing housing ring. This can be carried out in several parts as already stated. FIG. 7b illustrates the provision of the pressure block 9 with at least two partial regions, the guide region 14 and the support region forming the support and support function and the support surface 8. The pressure block 9 can be executed in the guide area 14 already with the incorporated portion of the annular groove 18. However, it is also conceivable to carry out the guide region 14 as a full segment also in the area flush with the outer circumference of the bearing housing 2. Furthermore, the individual tilting segments 5 are provided. In a further method step in FIG. 7c, the positioning of the individual components of bearing housing 2, pressure block 9 and tilting segment 5 takes place relative to one another. The individual pressure blocks 9 are introduced from the side of the inner circumference 22 of the bearing housing 2 into the passage opening 12 with the guide region 14. The guide portion 14 of the pressure block 9 is executed with respect to its extension in the installed position as a prefabricated basic component with an oversize. The positioning of the tilting segments 5 in their position defining the position takes place by positioning the tilting pad 5 relative to the respective Pressure block 9 and applying a pressure to the individual pressure block 9 and the tilting pad 5 against a centered in the bearing housing 2 adjusting bolts for setting the required tolerance. The fixing takes place by means of the rotation, here the set screw 16, which biases the pressure block 9 relative to the passage opening 12 in the radial direction, ie the pressure blocks 9 with the tilting pads 5 are pressed against an adjusting bolt and held by clamping the rotation 15 in position. These have, as already stated, in this position, a slight oversize relative to the outer circumference of the bearing housing 2. In a further process step by means of external cylindrical grinding a state shown in FIG 7d prepared in which the radial outer side 23 of the pressure block 9 and the outer diameter of the housing on a common cylindrical surface lie. This ensures that the inner circle, which tangentially touches the segments, describes the nominal size of the bearing with tolerance H6. The rotation 15 takes over in functional concentration during assembly of the bearing the task of fixing the position of the tilting pads 5 on the fixation of the printing blocks 9 and secures the pressure blocks 9 during operation against rotation with simultaneous play in the radial direction. In order to further increase the radial stiffness of the radial sliding bearing 1, the material of the pressure block 9 should have a modulus of elasticity which is greater than that of steel. As a result, values of more than 200 GPa are to be aimed for. The materials considered are technical ceramics. Technical ceramics have the advantage of a very good thermal conductivity. Furthermore, a lower coefficient of thermal expansion compared to previously used segment materials. Thus, the risk of impermissible reduction of the bearing clearance due to transient, thermal deformations and the resulting high storage temperatures, which can lead to the shutdown of the system is reduced. For the use of the bearing in bearing connection environments whose material properties differ from those of the bearing housing and in which there is a risk that during operation due to wear, the operation is impaired, the bearing housing 2 is enclosed by a bushing on the outer circumference. The outer circumference of the bush then forms the contact surface with the bearing connection environment and the pressure pieces are supported on the inner circumference of the bushing. FIG. 8 shows by way of example in a highly simplified representation such an embodiment in which the bearing housing 2, here by way of example consisting of two bearing housing shells, is surrounded by a support ring in the form of a bushing 29.

LIST OF REFERENCE NUMBERS

1 radial plain bearing

2 bearing housings

3 bearing bore

4.1, 4.2 bearing shell

5 tilting segment

6 support surface

7 storage area

8 wing

9 pressure block

10 outer circumference

1 1 shaft

12 passage opening

13 support area

14 management area

15 anti-twist device

16 threaded pin

17 side surface

18 side surface

19 ring groove

20 threaded hole

21 side window

22 inner circumference

23 radial outside

24 funds

25 Lubricant and Coolant Supply System

26 supply rails

27 inlet edge

28 outlet edge

29 socket

LA bearing axis

Claims

claims

1 . Radial plain bearings (1)

with a bearing housing (2) with a bearing bore (3) aligned along a bearing axis (LA) and a plurality of tilting segments (5) arranged circumferentially about the bearing housing (5) and movable relative to the bearing housing (LA) for supporting a shaft (1) 1), wherein the individual tilting segment (5) in each case has a radially outer bearing surface (7) for support on a bearing surface (8) on a pressure block (9) guided in the bearing housing (2);

characterized,

in that the individual pressure block (9) is guided in the radial direction movable in a radially through the bearing housing (2) extending through opening (12) free of a support on the bearing housing (2) by means of a rotation (15) against rotation in the circumferential direction the passage opening (12) is secured and the radial outer side of the pressure block (9) at least partially, preferably completely with the outer diameter of the bearing housing (2) or a sleeve enclosing this lies on a common cylinder surface.

2. Radial sliding bearing (1) according to claim 1,

characterized, in that the individual pressure block (9) has at least one guide region (14) for guiding in the bearing housing (2) and in installation position at the radially inner end region a support region (13) for forming the bearing surface (8), wherein the guide region (14) is designed in this way in that a clearance fit is provided between the outer circumference and the passage opening and the guide area has an extension in the radial direction which is dimensioned such that the support area (13) is free of contact with the inner circumference of the bearing housing (2).

Radial sliding bearing (1) according to one of claims 1 or 2,

characterized,

that the individual pressure block (9) and / or the individual tilting segment (5) is made of a material having a modulus of elasticity greater than 200 GPa, in particular greater than 250 GPa.

Radial sliding bearing (1) according to one of claims 1 to 3,

characterized,

that the through-opening in the bearing housing (2) is circular or oval when viewed in cross-section.

Radial plain bearing (1) according to one of the preceding claims,

characterized,

in that this comprises a lubricating and / or coolant supply system (25) which has at least one annular groove (19) extending over at least a partial area in the circumferential direction around the bearing housing (2) and which, viewed in the direction parallel to the bearing axis (LA), lies in the region of Lagermitte or eccentrically to this offset is arranged, wherein the annular groove (19) at least one radial bore in the bearing housing (2) with a between the individual tilting segments (5) and the inner periphery of the bearing housing (2) formed gap is connected.

6. Radial sliding bearing (1) according to one of the preceding claims,

characterized,

in that the anti-twist device (15) comprises a securing element, in particular a threaded pin, which acts positively with play on the guide region of the pressure block (9) and is guided through the wall of the bearing housing (2).

7. Radial sliding bearing (1) according to one of the preceding claims,

characterized,

the number of tilting segments (5) is between 3 and 7, preferably 3 and 5.

8. A method for assembling a radial sliding bearing (1) according to one of claims 1 to 7 with the following method steps:

- Providing a bearing housing (2) with a along a bearing axis (LA) aligned bearing bore (3) and a plurality of radially in relation to the bearing axis (LA) from the inner periphery to the outer circumference extending through holes (12);

- Providing printing blocks (9) with a support area (13) and in the longitudinal direction of the pressure block (9) adjoining guide portion (14) in the circumferential direction relative to the passage opening (12) with a clearance and an oversize relative to its extent in installation position Is designed longitudinally;

- Providing tilting segments (5);

- Introducing the pressure blocks (9) in the through holes (12) and fixing the pressure blocks (9) with excess on the outer circumference of the bearing housing (2) relative to the installed state of the radial sliding bearing (1) and the Kippsegmente (5) by means of a calibration device on the bearing housing (2 ) by setting the nominal size of the bearing in H6 tolerance - Work, especially cylindrical grinding of the outer circumference to the outer circumference of the bearing housing (2).

9. The method according to claim 8,

characterized,

in that the pressure block (9) is braced relative to the passage opening (12) by means of a securing element of a form-locking anti-rotation lock (15).

10. The method according to claim 8 or 9,

characterized,

that during machining of the outer circumference of the bearing housing (2) an annular groove (19) for a lubrication and cooling system (25) in the bearing housing (2) and / or the pressure block (9) is incorporated.