Bearing assembly comprising hydrodynamic plain bearings

Abstract

The invention relates to a bearing assembly comprising at least one first hydrodynamic plain bearing (1) and one second hydrodynamic plain bearing (2), the radial parts of the plain bearings having a different ratio of recess (A) to support surface of the bearing surface (3).

Description

[0001] Description

[0002] Bearing arrangement with hydrodynamic plain bearings

[0003] The present invention relates to a bearing arrangement with hydrodynamic plain bearings, as well as a rotor arrangement.

[0004] The object of the present invention is in particular to improve the efficiency of a bearing arrangement, and furthermore in particular to reduce power loss, in particular in an application with hydrodynamic plain bearings.

[0005] This object is achieved by a bearing arrangement having the features of claim 1. The subclaims relate to advantageous developments.

[0006] According to one embodiment of the present invention, a bearing arrangement is provided. In one embodiment, the bearing arrangement has at least one first, in particular hydrodynamic, plain bearing. In one embodiment, the bearing arrangement has at least one second, in particular hydrodynamic, plain bearing. In one embodiment, the, in particular radial parts, of the plain bearings have a different ratio of recess to support area of ​​the (inner) bearing surface. In one embodiment, the, in particular radial parts, of the first hydrodynamic plain bearing and of the second hydrodynamic plain bearing have a different ratio of recess to support area of ​​the (respective) bearing surface. The term “ratio” or the parts from which the ratio is formed, as used herein, does / do not refer in particular to a (circumferential) chamfer of the plain bearing orAny chamfer present is not included in the ratio, especially the absolute ratio, of the recess to the wing. In one embodiment, the ratio is an absolute ratio of the recess to the wing.

[0007] Advantageously, in one embodiment, this allows the bearing arrangement to be operated more efficiently, in particular power loss of the bearing arrangement can be reduced. The term “recess,” as used herein, is to be understood in particular as a radial and / or axial recess, in particular in sections, of the (sliding) surface of the plain bearing, in particular at least (on) one bearing shell of the plain bearing. In one embodiment, the recess is used to drain lubricant, in particular warm lubricant, and / or oil from the plain bearing. Advantageously, in one embodiment, the recess(es) can be used to reduce shear forces in the gap between the plain bearing and the rotor. Furthermore, in particular, the recess(es), which in particular also reduce the load-bearing sliding surface, can be used to reduce power loss, in particular in the plain bearing, or to increase the efficiency of the bearing arrangement.

[0008] The term “plain bearing”, as used herein, is to be understood in particular as the radial part of a plain bearing, further in particular as the radial part of an axial-radial plain bearing, in particular without restriction of generality.

[0009] In one embodiment, the first plain bearing has a smaller recess-to-supporting surface ratio, particularly compared to the second plain bearing. In one embodiment, the recess in the first plain bearing is smaller (in terms of area) than the recess in the second plain bearing; in particular, the supporting surface of the first plain bearing is larger (in terms of area) than that of the second plain bearing. In one embodiment, the ratio of the recess to the supporting surface of the (inner) bearing surface of the first plain bearing is smaller than the ratio of the recess to the supporting surface of the second plain bearing.

[0010] In one embodiment, this can advantageously reduce power loss in the bearing arrangement.

[0011] In one embodiment, the ratio of the recess to the supporting surface in the first plain bearing is at least 5%P (percentage points), at least 10%P, at least 15%P, at least 20%P, at least 25%P or at least 30%P smaller than the ratio of the recess to the supporting surface in the second plain bearing and / or at most 40%P, at most 35%P or at most 30%P smaller than the ratio of the recess to the supporting surface in the second plain bearing. In one embodiment, the ratio of the recess to the supporting surface in the second plain bearing is at least 10%P, at least 15%P, at least 20%P, at least 25%P or at least 30%P greater than the ratio of the recess to the supporting surface in the first plain bearing and / or at most 40%P, at most 35%P or at most 30%P greater than the ratio of the recess to the supporting surface in the first plain bearing.In one embodiment, the recess on the supporting surface in the first plain bearing is at least 5%P, at least 10%P, at least 15%P, at least 20%P, at least 30%P smaller than in the second plain bearing and / or at most 40%P, at most 30%P smaller than in the second plain bearing.

[0012] In one embodiment, this advantageously allows the power loss to be reduced, in particular the ratio of recess to supporting surface of the first and second plain bearings to be matched to the dynamic forces to be absorbed by the bearing arrangement.

[0013] In one embodiment, the first plain bearing is arranged on a side of the bearing arrangement that has a larger static overhang, in particular compared to the other side of the bearing arrangement. In one embodiment, the second plain bearing is arranged on a side of the bearing arrangement that has a smaller static overhang, in particular compared to the other side of the bearing arrangement, further in particular compared to the side of the bearing arrangement on which the first plain bearing is arranged. In one embodiment, the first plain bearing is arranged on a side of the bearing arrangement that has a larger static overhang moment, in particular compared to the other side of the bearing arrangement.In one embodiment, the second plain bearing is arranged on a side of the bearing arrangement that has a smaller static overhang moment, in particular compared to the other side of the bearing arrangement, further in particular compared to the side of the bearing arrangement on which the first plain bearing is arranged. In one embodiment, the first plain bearing is arranged such that it absorbs a larger static overhang moment or is used for this purpose, in particular compared to an arrangement of the second plain bearing that in particular absorbs a smaller static overhang moment or is used for this purpose.

[0014] Advantageously, this allows power loss, particularly in the bearing assembly, to be reduced, and furthermore, the bearing assembly can be used more efficiently. Advantageously, in one embodiment, a reduction in oil quantity in the plain bearing or the bearing assembly can be achieved, particularly indirectly, because the removal of the warm oil or warm lubricant using the recess(es) reduces the average temperature in the bearing gap, in particular the entire bearing gap, and thus, in particular, an (additional) increase in oil consumption is not necessary or may not be necessary, in order to reduce the average gap temperature in the bearing.

[0015] The term "static overhang" or "static overhang moment," as used herein, should preferably be understood to mean the overhang of a rotor or the like mounted by means of the bearing arrangement. In one embodiment, an overhang or overhang moment includes, in particular in addition to the actual rotor overhang, a component or components connected to the rotor, such as in particular hub(s), flange(s), coupling(s), or the like. In particular, an overhang or overhang moment can increase or is greater in one embodiment if, in particular, two rotors (or the like) are coupled or (operatively) connected via a coupling, wherein the mass(es) of the (individual) coupling elements, in particular their effective distances, act on the two coupled or (operatively) connected rotors (or the like), so that in particular their static overhang or their static overhang moment is or is increased.In particular, in one embodiment, less damping is required from the plain bearing on the side with the smaller static overhang to suppress self-excited subsynchronous vibrations. This can be advantageously achieved, in one embodiment, by at least one recess in the (second) plain bearing—as described herein.

[0016] In one embodiment, the second plain bearing is arranged on a side of the bearing arrangement facing away from the clutch. Alternatively or additionally, the second plain bearing is arranged on a non-drive side.

[0017] As a result, in one embodiment, the bearing surface or supporting surface of the second plain bearing can advantageously be reduced, in particular in a targeted manner, so that power loss of the bearing arrangement can be reduced, in particular compared to a bearing arrangement with identical plain bearings or conditions. In one embodiment, the recess is arranged in sections on a bearing shell that is at least substantially unloaded (during operation). In one embodiment, the recess has a plurality of, in particular connected and / or separate, sections, in particular on an (unloaded) bearing shell of the, in particular first and / or second, plain bearing.

[0018] In one embodiment, this advantageously allows a (sufficient) damping characteristic to be achieved, particularly during operation with low (radial) loads, by means of the lubricating film within the wings and a power loss to be reduced.

[0019] In one embodiment, the recess is formed, in particular in sections, on an unloaded bearing shell and / or at least in sections on a loaded bearing shell, in particular in a second plain bearing, in particular in the first and second plain bearings. In one embodiment, the ratio between the recess and the supporting surface is smaller in the first plain bearing than in the second plain bearing.

[0020] In one embodiment, this can advantageously reduce the power loss, especially when (sufficient) safety is provided for the dynamic loads that occur.

[0021] In one embodiment, the recess of a plain bearing is designed such that it occupies at least one axial section of the bearing surface, in particular in sections at most 100% of the bearing surface, at most 75%, at most 50% or at most 30% of the bearing surface and / or in sections at least 1%, at least 2%, at least 3%, at least 5%, at least 10%, at least 20% or at least 25% of the bearing surface, in particular, in one embodiment, in sections 0% of the bearing surface. In one embodiment, a recess boundary and / or recess edge spaced from an axial side surface of the plain bearing runs at least substantially parallel to the axial side surface of the plain bearing or is designed such that, in particular in sections, an axial distance between the recess boundary and / or the recess edge and the axial side surface of the plain bearing changes, in particular continuously or discontinuously.In one embodiment, the recess boundary and / or the recess edge is formed as a, in particular continuous, curve in the bearing surface.

[0022] In one embodiment, the recess is formed in a plan view of the unrolled bearing surface of the plain bearing in a rectangular, triangular, circular and / or circular segment-like manner; in particular, in one embodiment, in a plan view of the unrolled bearing surface of the plain bearing, the recess is formed as a combination of several geometric figures, such as polygons, circles or the like, in particular as a free form.

[0023] In one embodiment, the recess in a rolled bearing surface is cuboid-like, cylinder-(segment-)like, cone-(segment-)like and / or spherical, in particular as a combination of one or more spatial geometric figures.

[0024] In one embodiment, this makes it possible to achieve particularly advantageous oil (discharge) management, in particular to guide the oil quantity (more specifically) and / or to reduce an average gap temperature and / or (gap) shear forces in the area of ​​the recess(es).

[0025] In one version, the transition between the support surface or bearing surface and the recess is sharp-edged. In another version, the transition between the support surface or bearing surface and the recess is continuous and / or rounded.

[0026] In one embodiment, the radial depth of the recesses, in particular on both sides, in particular in the edge areas of the bearing surface, is several millimeters, whereby, in one embodiment, a complete radial penetration of the bearing shell can also be formed. In one embodiment, the recess is arranged or provided, in particular for the most part, in the unloaded bearing surface of the plain bearing.

[0027] In one embodiment, the first plain bearing and / or the second plain bearing, as described herein, comprises or is designed as a fixed-shell plain bearing. In one embodiment, the first plain bearing and / or the second plain bearing does not comprise or is not designed as a tilting-pad plain bearing, in particular with tiltable radial segments. In one embodiment, this advantageously allows the power loss of the bearing arrangement to be reduced.

[0028] According to one embodiment of the invention, a rotor assembly is provided. In one embodiment, the rotor assembly comprises at least one rotor or at least one shaft or the like. In one embodiment, the rotor assembly comprises a bearing assembly as described herein. In one embodiment, the at least one rotor is mounted using a bearing assembly as described herein.

[0029] In rotor dynamics, smaller static rotor overhangs or static overhang moments usually lead to smaller lateral (or radial) deflections or orbits or dynamic forces within the rotor overhang. During operation, the oil film of a journal bearing usually counteracts the dynamic forces due to its stiffness and damping characteristics. The two conical oil film modes that typically occur in conjunction with fixed-shell journal bearings during operation with low bearing loads (so-called rigid body modes, in which the rotor, which is stiff relative to the lubricating film, oscillates with a wobbling motion around its rotation axis within the radial clearances of at least two journal bearings without bending significantly) can be differentiated using their vibration shapes such that the mode that forms its largest orbit along the theoretical rotor axis in the direction of the larger rotor overhang generally exhibits lower damping.In contrast, the mode which forms its largest orbit along the theoretical rotor axis in the direction of the smaller rotor overhang generally exhibits greater damping. Because the vibration shapes of the two modes differ so much, the damping of a conical mode can, for example, be influenced by the introduction of recesses within a single journal bearing, in one design (advantageously), almost independently of the properties of another conical mode. Since the damping of rigid-body modes can usually be evaluated as a measure of safety against the occurrence of oil film instabilities, this can be achieved, particularly by targeted reduction of the bearing surface orThe sliding surface of a, in particular second, plain bearing (as described herein) can reduce the power loss and, in particular, advantageously make the rotor application more efficient, particularly while still maintaining (design) values ​​sufficient for safety. In particular, the inventor has recognized through measurements that the power loss of the bearing is reduced, or can be significantly reduced, using a bearing arrangement described herein while maintaining at least substantially constant operating parameters, such as rotor speed, power or torque, and oil data.

[0030] Further advantages and features emerge from the subclaims and the exemplary embodiments. The following shows, partly schematically:

[0031] Fig. 1 : a bearing arrangement according to an embodiment of the present invention;

[0032] Fig. 2: a rotor arrangement in a perspective and a side view according to an embodiment of the present invention; and

[0033] Fig. 3: Recesses according to embodiments of the present invention.

[0034] Fig. 1 shows a bearing arrangement, in particular for a rotor. The rotor in Fig. 1 has a smaller overhang on the left side of the schematic representation than on the right side. Accordingly, on the left side, a plain bearing, described here in particular as a second plain bearing 2, is arranged, the bearing surface of which has a support surface and lateral recesses A, wherein their ratio to one another (recess A to support surface) is greater in the plain bearing on the left side than in the schematically shown plain bearings 1, T on the right side, which are described in the above description in particular as first plain bearings 1, T. The recesses A shown are each formed, in particular predominantly, in the unloaded bearing shell of the plain bearings, but in one embodiment can also be formed, in particular at least partially, in the loaded bearing shell (in particular during operation), wherein

[0035] “loaded” refers in particular to the fact that the (nominal load) vector of the bearing force is located in this bearing shell. A further (first) plain bearing T is shown in dashed lines, which, in a design without recesses, alternatively (to the plain bearing 1) supports the right-hand side of the rotor (radially) in the illustration. Fig. 2 shows a further schematic rotor arrangement in a perspective view and a schematic side view, in which the rotors or shafts, in particular gear (parts), are mounted by means of bearing assemblies, as described herein. The arrangement shown by way of example has a gear with bearing assembly G1, G2, G'1 and G'2. The second plain bearings 2, as described herein, are, particularly advantageously, arranged at G2 and G'2 in the schematic illustration in Fig. 2, the remaining plain bearings correspond to first plain bearings 1, as described herein.This bearing arrangement(s) each have second plain bearings 2, as described herein, on the side of the rotors or shafts to be radially supported, with the comparatively smaller static overhang or comparatively smaller static overhang moment. From this it is particularly evident that couplings, flanges and / or hubs contribute to the overhang / overhang moment, in particular their masses. From the side view in Fig. 2 it is particularly evident that a recess or recesses are or can be arranged differently in the plain bearing 1, 2 depending on the direction of rotation and / or drive side. In the schematic side view of Fig. 2 the drive is in the direction of the arrow on the smaller (left) wheel.As a result, the toothing is supported, for example, in such a way that an at least substantially unloaded surface section of the sliding surface of the plain bearing of the small wheel is located at least substantially at the bottom (relative to the figure sheet), and in the case of the large (right-hand) wheel, at least substantially at the top. The arrangement of the recess(es) is thus, in one embodiment, dependent on a (nominal) load vector F, and the recess(es) is / are arranged, at least substantially, in the surface section of the plain bearing which is at least substantially opposite the (nominal) load vector F, in particular in the at least substantially unloaded surface section of the plain bearing 1, 2, and furthermore in particular in the sliding surface section of the plain bearing which is usually referred to as the unloaded segment (“non-load segment”). Accordingly, the (nominal) load vector F changes in the case of an opposite direction of rotation, in particular, in one embodiment, the arrangement orLocation of the recess(es).

[0036] Fig. 3, in sub-figures A to F, schematically shows recesses A1 to A6 of the bearing surfaces 3 in different embodiments in a plan view. The upper row of exemplary embodiments each shows recesses A1-A3 that are symmetrical to a theoretical center line (theoretical axial bearing center of the radial part) of the plain bearing. The lower row shows asymmetrically arranged recesses A1-A6 with respect to the theoretical axial bearing center. The recesses A1-A5 can, in particular with respect to the bearing surface 3, have a rectangular (see A), triangular (see B) or circular (segment)-like (not shown) recess A1-A5 in a rolled-out representation, which is designed symmetrically in particular to the axial bearing center, as shown in particular in sub-figures A, B and C of Figure 3.The recesses A1-A6 can alternatively or additionally, in one embodiment, be designed asymmetrically, as shown schematically in particular in sub-figures D to F of Figure 3. There, in sub-figure D, two rectangular recesses A1, A2 are combined asymmetrically to the axial bearing center (dotted line) or, as shown in sub-figure E, with a triangular and a circular segment-like recess A3, A4. Sub-figure F of Fig. 3 shows a recess A5 with a radius-like edge and a free-form recess A6. In embodiments, further or other combinations of geometric figures are designed as recesses. The arrows in Fig. 3 indicate a possible direction of rotation 5 of a shaft or a rotor on the bearing surface.Figure 3 does not show a division into loaded and unloaded bearing shell, wherein the recesses are preferably formed, in embodiments, on the unloaded bearing shell and / or the unloaded segment (“non-load segment”) of the plain bearing 1.

[0037] Although exemplary embodiments have been explained in the preceding description, it should be noted that a multitude of modifications are possible. Furthermore, it should be noted that the exemplary embodiments are merely examples and are not intended to limit the scope of protection, applications, or structure in any way. Rather, the preceding description provides the skilled person with a guide for implementing at least one exemplary embodiment, whereby various changes, particularly with regard to the function and arrangement of the described components, can be made without departing from the scope of protection as it results from the claims and equivalent combinations of features.

[0038] 1 , 1' first hydrodynamic plain bearing

[0039] 2 second hydrodynamic plain bearing 3 bearing surface (inside)

[0040] 4 Rotor

[0041] 5 Direction of rotation of the rotor

[0042] A, A1 ... A6 recess(es)

[0043] F Nominal load vector

Claims

Patent claims 1. Bearing arrangement comprising: at least a first hydrodynamic plain bearing (1) and a second hydrodynamic plain bearing (2), wherein the radial parts of the plain bearings have a different ratio of recess (A) to supporting surface of the bearing surface (3).

2. Bearing arrangement according to the preceding claim, characterized in that the first plain bearing (1) has a smaller ratio compared to the second plain bearing (2).

3. Bearing arrangement according to one of the preceding claims, characterized in that the ratio in the first plain bearing (1) is at least 5%P smaller than in the second plain bearing (2).

4. Bearing arrangement according to one of the preceding claims, characterized in that the first plain bearing (1) is arranged on a side of the bearing arrangement which has a larger static overhang compared to the other side of the bearing arrangement.

5. Bearing arrangement according to one of the preceding claims, characterized in that the second plain bearing (2) is arranged on a side of the bearing arrangement facing away from the clutch and / or on a non-drive side.

6. Bearing arrangement according to one of the preceding claims, characterized in that the recess (A) is arranged in sections, in particular having a plurality of sections, on an unloaded bearing shell of the, in particular second, plain bearing.

7. Bearing arrangement according to one of the preceding claims, characterized in that the recess (A), in particular in sections, is formed in each case on an unloaded bearing shell and / or in each case at least in sections on a loaded bearing shell of the second plain bearing (2), in particular of the first plain bearing (1) and of the second plain bearing (2).

8. Rotor arrangement, in particular a gearbox, with at least one bearing arrangement according to one of the preceding claims and a rotor which is mounted in particular by means of the bearing arrangement.

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