Bearing arrangement, wind turbine and method for setting a bearing arrangement

Abstract

The present invention relates to a bearing arrangement (1) having a force sensor system (9), in particular for a wind turbine, and comprising a bearing ring (10) fixed to the housing, namely an outer ring, in which a plurality of sliding bearing segments (4), which are provided together for the radial mounting of a shaft, is mounted, each sliding bearing segment (4) being supported on the bearing ring (10) by an axial sliding bearing (3), and a force measuring ring (6) being provided for measuring a force acting between the sliding bearing segment (4) and the bearing ring (10), which force measuring ring is arranged between the axial sliding bearing (3) and the bearing ring (10).

Description

[0001] Lake arrangement, wind turbines and

[0002] Procedure for setting a storage order

[0003] The invention relates to a bearing arrangement designed as a plain bearing with a load measuring device, i.e., a force sensor. Furthermore, the invention relates to a wind turbine and a method for adjusting a bearing arrangement, particularly in a wind turbine.

[0004] JP 2004 144 596 A2 discloses a device for detecting an axial force acting on a plain bearing supporting a shaft. A ring is mounted on the shaft, which has a circumferential collar, i.e., a radially outward-facing rim. The collar can be supported on a housing-fixed disk in the axial direction of the device according to JP 2004 144 596 A2. The disk, in turn, is supported on an element equipped with force measurement technology.

[0005] A device disclosed in JP 2011 169 418 A is intended for measuring forces on an axial bearing. The axial bearing comprises several pads arranged in an annular space. Furthermore, the axial bearing comprises several force measuring cells assigned to the pads.

[0006] A device for measuring axial bearing forces, known from DE 10 2008 052 189 A1, is intended in particular for measuring forces occurring in an exhaust gas turbocharger. It is proposed to measure axial forces using a strain gauge circuit. Furthermore, the device according to DE 10 2008 052 189 A1 includes an evaluation device.

[0007] Another device with a strain sensor is described, for example, in DE 10

[0008] 2018 132 252 B4. The strain sensor is intended to detect strain in at least one direction of movement and, in the case of DE 10 2018 132 252 B4, is used on a linear bearing. Temperature-related fluctuations in the strain amount are to be compensated.

[0009] Various measuring devices that measure loads on bearings using optical means are described, for example, in the documents DE 10 2004 043 754 B3 and DE 10 2004 043 752 B4.

[0010] DE 38 28 550 A1 discloses a force measuring ring intended for use in a spindle drilling machine. The force measuring ring comprises a ring body and several strain gauges.

[0011] A thrust sensor assembly described in EP 1 007 925 B1 comprises a plurality of pressure plate devices, wherein at least one of the pressure plate devices engages at least indirectly with a shaft for axial movement with the shaft. An elastically compressible buffer is located between the two pressure plate devices. A pressure transducer is mounted on one of the two pressure plate devices.

[0012] The invention is based on the object of providing means of force sensor technology in bearing arrangements, in particular in wind turbines, which are more advanced than the prior art, whereby usability is sought already during the assembly of a bearing, but also within the subsequent, completely assembled system.

[0013] This object is achieved according to the invention by a bearing assembly equipped with a force sensor according to claim 1. The bearing assembly is particularly suitable for use in a wind turbine according to claim 6. Furthermore, the object is achieved by a method for adjusting a bearing assembly according to claim 7. The embodiments and advantages of the invention explained below in connection with the adjustment method also apply mutatis mutandis to the devices, i.e., the wind turbine and the bearing assembly, and vice versa.

[0014] According to claim 1, the bearing assembly equipped with a force sensor comprises a bearing ring fixed to the housing, namely the outer ring. The term outer ring is used regardless of whether the bearing ring is constructed in one or more parts, although a construction consisting of several spaced-apart elements is also possible. Likewise, the outer ring can be connected directly or indirectly to a housing or even formed directly by the housing. In any case, several plain bearing segments, which together are intended for the radial bearing of a shaft, are mounted in the outer ring. Each plain bearing segment is supported on the bearing ring by an axial plain bearing. To measure a force acting between the plain bearing segment and the bearing ring, a force measuring ring is provided, which is arranged between the axial plain bearing and the bearing ring.

[0015] The bearing assembly as a whole is designed specifically for the hydrodynamic plain bearing support of a shaft. Each of the plain bearing segments is designed to support the shaft in the radial direction. In the case of a large-diameter bearing assembly, the plain bearing segments located in the lower area of ​​the bearing assembly are particularly subject to gravity. Therefore, in many applications, it is advisable not to place the plain bearing segments at equal angular intervals around the center axis of the shaft and the entire bearing assembly, but rather to provide a denser arrangement of plain bearing segments in the lower area of ​​the bearing assembly compared to the rest of the bearing assembly.If the space available for installing the plain bearing segments is divided geometrically into four segments of 90 degrees each, i.e. a lower left, an upper left, a lower right, and an upper right segment, plain bearing segments can be arranged in all four segments, or in some applications only in the two lower segments. In any case, viewed in the circumferential direction of the bearing arrangement, there is free space between individual plain bearing segments. The axial plain bearings, which support the individual plain bearing segments, transmit forces that act between the shaft and the bearing ring at least approximately in the radial direction, relative to the center axis of the entire bearing arrangement. Viewed from the axial plain bearings, this direction is their axial direction. Axial plain bearings can be, for example, tilting bearings or spherical plain bearings.In any case, the placement of the force measuring rings between each axial plain bearing and the bearing ring provides both a space-saving housing for the sensor system in the form of the force measuring rings, well protected from unwanted external influences, and a sufficiently high level of force measurement precision for the specific case. Force measuring rings can be assigned to either a subset of the plain bearing segments or all of the plain bearing segments.

[0016] The force measuring ring is placed, for example, between a housing plate belonging to the axial plain bearing and the bearing housing. In this case, the housing plate may contact both the force measuring ring and the bearing ring. In particular, the force measuring ring can be arranged in a recess in the bearing ring that is at least largely covered by the housing plate.

[0017] The bearing assembly may comprise a plurality of hydraulic cylinders arranged in the lower half of the bearing ring and designed to lift a shaft along with a load connected to the shaft. The hydraulic cylinders are used particularly in cases where the supported shaft loads the bearing assembly not only with its own weight but also with machine elements connected to the shaft.

[0018] The method according to the application for adjusting a bearing arrangement, which may in particular be intended for installation in a wind turbine or may already be installed in a wind turbine, generally comprises the following steps: - providing a bearing arrangement according to claim 1 and a shaft placed in the bearing arrangement,

[0019] - Measurement of forces acting between the shaft and the bearing ring by means of a plurality of force measuring rings arranged between the shaft and the bearing,

[0020] - Lifting the shaft within the bearing arrangement,

[0021] - Adjustment of all plain bearing segments in such a way that a force acts between each plain bearing segment and the shaft,

[0022] - Relief of at least a subset of the plain bearing segments in such a way that a defined play of the bearing arrangement is established.

[0023] Particularly in cases where the shaft is not loaded by other machine elements, it is possible to lift the shaft exclusively using the plain bearing segments. Otherwise, the shaft can be lifted hydraulically. This involves using several hydraulic cylinders located between individual plain bearing segments, particularly in the lower half of the bearing arrangement, to firstly apply a uniform load to the plain bearing segments mounted in the lower half of the bearing arrangement. The hydraulic cylinders are then used to apply a uniform load to the plain bearing segments in the upper half of the bearing arrangement, and finally to apply a uniform load to the plain bearing segments in the left and right halves of the bearing arrangement.

[0024] An exemplary embodiment of the invention is explained in more detail below with reference to a drawing. The drawings show, in some simplified form:

[0025] Fig. 1 Components of a segmented bearing arrangement with force sensors in a sectional view,

[0026] Fig. 2 shows the arrangement according to Figure 1 in a further representation, Fig. 3 and 4 show in flow diagrams different variants of adjustment methods which can be carried out on the bearing arrangements according to Figures 1 and 2.

[0027] A bearing assembly, designated overall by reference numeral 1, is designed as a segmented plain bearing and intended for use as a main rotor bearing in a wind turbine (not shown in detail). The bearing assembly 1 comprises an annular housing element 2, which in this case functions as an outer ring 10 of the bearing assembly 1, i.e., forms a bearing. The bearing 10 can be composed of any number of individual parts. Within the housing element 2, several plain bearing segments 4 are mounted by means of axial plain bearings 3. The designation of the latter plain bearings 3 as axial plain bearings means that an axial force acts on the respective bearings 3. With respect to the entire bearing assembly 1, this is a radial force. The corresponding radial forces act between a shaft supported by the bearing segments 4 and the outer ring 10.Thanks to the axial plain bearings 3, each bearing segment 4 is angularly adjustable to a limited extent. Each axial plain bearing 3 has at least one degree of freedom, which is the case with a tilting bearing design. In the illustrated example, as is typical for spherical plain bearings, the axial plain bearings 3 have several degrees of freedom.

[0028] Viewed parallel to the longitudinal axis of the shaft to be supported by the bearing assembly 1, four quadrants QI to Q IV of the bearing assembly 1 can be defined, as shown in Figure 2. In the embodiment shown, each of these quadrants QI, Q II, Q III, Q IV contains two plain bearing segments 4 and, accordingly, two axial plain bearings 3, which in the present case are designed as spherical plain bearings. In the two lower quadrants Q III, Q IV, two additional hydraulic cylinders 8 are located, which, as will be explained in more detail below, can be used to adjust the bearing assembly 1. As shown in Figure 1, each axial plain bearing 3 is supported on the outer ring 2 via a segment support 5, also referred to as a housing plate. Screws 7 are provided for fastening the segment support 5 to the housing element 2. A recess 11 is formed through the housing element 2, which is covered by the housing plate 5.Located in the recess 11, although not completely filling it, is a measuring ring 6 for detecting a force acting on the axial plain bearing 3. The measuring ring 6 is part of a force sensor system designated 9.

[0029] A first option for adjusting the bearing assembly 1 is explained below using Figure 3. Here, S1 denotes the start of the adjustment process. The positioning of the shaft in the bearing assembly 1, designated as step S2, can be performed at any time before the subsequent steps are carried out. In the scenario shown in Figure 3, it is assumed that the shaft is not significantly loaded by other machine elements, such as a wind turbine rotor connected to the shaft.

[0030] In step S3, the shaft, which initially rests on the plain bearing segments 4 in the lower quadrants Q III, Q IV, is raised by a defined amount without touching the plain bearing segments 4 in the two upper quadrants Q I, Q II. This is achieved by adjusting the plain bearing segments 4 located in the two lower quadrants Q III, Q IV.

[0031] In the following step S4, it is checked whether the shaft is in contact with all plain bearing segments 4. If this is not the case, step S3 is repeated. Otherwise, the load on the bearing segments 4 is further increased in step S5. In step S6, the occurring loads are measured. If necessary, the load on the plain bearing segments 4 is increased again in step S5. Ultimately, after several runs through steps S5 and S6, a uniform load on all axial plain bearings 3 is achieved. In the following step S7, the height setting of the plain bearing segments 4 is reduced again with the aim of adjusting the play. A plain bearing segment 4 is said to be raised higher when the distance of the respective plain bearing segment 4 from the center axis of the bearing arrangement 1 is reduced. This applies regardless of which quadrant QI to Q IV the plain bearing segment 4 is located in.Thus, raising a plain bearing segment 4 in one of the two upper quadrants QI, QII is accompanied by a geodetic lowering of the respective plain bearing segment 4. In step S8, a check is carried out to determine whether the desired clearance setting has already been achieved. If necessary, step S7 is repeated. Finally, step S9 marks the end of the adjustment process according to Figure 3.

[0032] The flow chart in Figure 4 refers to a scenario in which the shaft mounted in the bearing arrangement 1 is already installed in a wind turbine and loaded with the mass of the wind turbine's rotor. In this case, the hydraulic cylinders 8 are used to relieve the shaft. In this case, too, step S1 marks the start of the adjustment process. In step S2, the forces acting on the bearing segments 4 located in the lower quadrants Q III, Q IV are measured. In step S3, the target positions of the individual plain bearing segments are calculated with the aim of even load distribution. The relief of the shaft by actuating the hydraulic cylinders 8 begins in step S4. Subsequently, in step S5, the height settings of the bearing segments 4 located in the lower quadrants Q III, Q IV are changed.

[0033] In step S6, load measurements are taken in the lower segments Q III, Q IV. Steps S4 and S5 are repeated if necessary until the forces in the two lower bearing segments Q III, Q IV are at least approximately evenly distributed. In step S7, the height setting of the shaft is changed using the hydraulic cylinders 8. The displacement made is measured in step S8. The play is adjusted in step S9. On the basis of a force measurement, a check is carried out in step S10 as to whether the goal of even loading of the plain bearing segments 4 in the area of ​​the upper segments QI, Q II has been achieved. If this is not the case, the height adjustment parameters are redefined in step S11 and steps S7 to S9 are repeated.

[0034] Otherwise, the horizontal position of the shaft is adjusted in steps S12 to S15. In step S12, the hydraulic cylinder 8 which is closest to the boundary between quadrant QI and quadrant QIV, i.e. which is closest to the 3 o'clock position, is actuated first. In the present case, this is a hydraulic cylinder 8 in the 4 to 5 o'clock position. By actuating this hydraulic cylinder 8, the shaft can be displaced to the left with respect to the arrangement shown in Figure 2. This results in increased loads in quadrants QII and QIII, which are measured in step S14. In step S15, a check is carried out to determine whether the plain bearing segments 4 in quadrants QII and QIII are at least approximately evenly loaded.Once this is the case, steps S12 to S14 are repeated, whereby in this case the load on the plain bearing segments 4 in quadrants QI, Q IV is adjusted with the aid of a hydraulic cylinder 8 located in quadrant Q III. After forces acting in the lateral direction have also been adjusted in this way, the adjustment process according to Figure 4 is concluded with step S16.

[0035] List of reference symbols

[0036] 1 bearing arrangement

[0037] 2 housing element

[0038] 3 axial plain bearings

[0039] 4 plain bearing segment

[0040] 5 segment support, housing plate

[0041] 6 force measuring ring

[0042] 7 screw

[0043] 8 hydraulic cylinders

[0044] 9 Force sensors

[0045] 10 Outer ring, bearing ring

[0046] 11 Recess

[0047] Q I... Q IV Quadrant

[0048] S1... S16 Step

Claims

Patent claims 1. Bearing arrangement (1) with force sensors (9), comprising a housing-fixed bearing (10), namely an outer ring, in which a plurality of plain bearing segments (4) are mounted, which together are provided for the radial bearing of a shaft, wherein each plain bearing segment (4) is supported on the bearing (10) by an axial plain bearing (3), and wherein a force measuring ring (6) is provided for measuring a force acting between the plain bearing segment (4) and the bearing ring (10), which force measuring ring is arranged between the axial plain bearing (3) and the bearing ring (10).

2. Bearing arrangement (1) according to claim 1, characterized in that the force measuring ring (6) is placed between a housing plate (5) attributable to the axial plain bearing (3) and the bearing ring (10).

3. Bearing arrangement (1) according to claim 2, characterized in that the housing plate (5) contacts both the force measuring ring (6) and the bearing ring (10).

4. Bearing arrangement (1) according to claim 2 or 3, characterized in that the force measuring ring (6) is arranged in a recess (11) of the bearing ring (10) which is at least largely covered by the housing plate (5).

5. Bearing arrangement (1) according to one of claims 1 to 4, characterized by a plurality of hydraulic cylinders (8) which are arranged in the lower half (Q III, Q IV) of the bearing ring (10) and are designed to lift a shaft together with a load connected to the shaft.

6. Wind turbine comprising a bearing arrangement (1) according to claim 1.

7. Method for adjusting a bearing arrangement (1 ), comprising the following steps: - Providing a bearing arrangement (1) comprising a plurality of plain bearing segments (4) according to claim 1 and a shaft placed in the bearing arrangement (1), - measuring forces acting between the shaft and a bearing ring (10) of the bearing arrangement (1) by means of a plurality of force measuring rings (6) arranged between the shaft and the bearing ring (10), - Lifting the shaft within the bearing arrangement (1 ), - Adjustment of all plain bearing segments (4) in such a way that a force acts between each plain bearing segment (4) and the shaft, - Relieving the load on at least a subset of the plain bearing segments (4) in such a way that a defined play of the bearing arrangement (1) is established.

8. Method according to claim 7, characterized in that the shaft is lifted exclusively with the aid of the plain bearing segments (4).

9. Method according to claim 7, characterized in that the shaft is raised hydraulically, wherein hydraulic cylinders (8) which are arranged between individual plain bearing segments (4) are used to first set a uniform load on the plain bearing segments (4) mounted in the lower half (Q III, Q IV) of the bearing arrangement (1), then a uniform load on the plain bearing segments (4) located in the upper half (QI, Q II) of the bearing arrangement (1) and finally a uniform load on the plain bearing segments (4) located in the left half (Q II, Q III) and in the right half (QI, Q IV) of the bearing arrangement (1).

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