DK179778B1

DK179778B1 - Improved bearing and method of operating a bearing

Info

Publication number: DK179778B1
Application number: DKPA201770699A
Authority: DK
Inventors: Kilian Allan; Kjaer Ole; Kurt Christensen Claus
Original assignee: Envision Energy (Denmark) Aps
Priority date: 2017-09-15
Filing date: 2017-09-15
Publication date: 2019-05-28
Also published as: CN111356847A; DK201770699A1; CN111356847B; WO2019052619A1

Abstract

Disclosed is a bearing with an inner part rotatably arranged relative to an outer part for rotation about an axis and extending in the axial direction. The bearing may have multiple thermal sensors arranged in the axial direction and configured to provide a thermal profile in the axial direction. Also disclosed are methods for operating a bearing and methods of producing or modifying bearings.

Description

A bearing and method of operating a bearing

Field of the Invention

The present invention relates to a bearing, processes of providing a bearing, and methods of operating a bearing.

Background of the Invention

Bearings are known in various sizes. Bearings may be large scale bearings in modern wind turbine generators, ships, generators or the like, where forces are exceptional and lifetime, including lifetime forecast, is important. Not only important in view of lifetime for the structure alone, but the technical complexity of maintenance and the cost of down-time.

Patent application WO 2007/128877 A1 discloses a roller bearing with thermal sensors arranged to provide information about the temperature in the bearing in a radial direction.

Object of the Invention

An object is to provide an improved bearing. Furthermore, an object is to provide improved methods of operating a bearing or usage of a bearing during operation.

An object is to provide an improved bearing taking advantages of unexpected thermal characteristics of bearings during operation.

An object is to provide a new bearing based on an existing bearing.

Finally, an object is to provide an improved wind turbine generator using an improved bearing, and it is an objective to improve operation of a wind turbine generator.

Description of the Invention

An object is achieved by a bearing with an inner part rotatably arranged relative to an outer part for rotation about an axis and extending in the axial direction. The bearing may have multiple thermal sensors arranged in an axial direction and configured to provide a thermal profile in the axial direction.

The inner part may be an inner ring or inner race. The outer part may be an outer ring or outer race. The inner part may be formed in a shape according to circumstances. Likewise, the outer part may be formed in a shape according to circumstances. The outer part may have an inward facing face with a circular cross-section. The inner part may have an outward facing face with a circular cross-section.

One of the inner or outer parts may be stationary relative to a reference frame. The inner and outer part may also be rotatable or movable relative to a reference frame.

The bearing in principle may be any type or size of bearing.

Thereby, the thermal profile will provide thermal or temperature information readily resulting in thermal gradients i.e. temperature gradients providing hereto unavailable and overseen information to improve the bearing.

Thereby, also improving lifetime expectancy or at least improve lifetime forecasting of a bearing.

The outer part and the inner part may be communicating, e.g. by mechanical contact, with each other directly. In that case, the outer part has an inward facing face complementary to an outward facing face of the inner part.

There may be an intermediate structure between the inner part and the outer part. One intermediate structure may comprise a retainer which retainer may be suspended in between the outer and inner parts by balls, rollers or similar gliders. In an embodiment, the respective inward face of the outer part and the outward face of the inner part may have faces shaped to support balls, roller or similar gliders.

In an embodiment, the inner part and the outer part may be suspended relative to each other by means of a solid suspension element.

In an embodiment, the inner part and the outer part may be suspended relative to each other by a magnetic suspension arrangement.

In an embodiment, there may be a suspension arrangement of one type forming the communication with the outer part and a suspension arrangement of another type forming the communication with the inner part. There may e.g. be a magnetic suspension arrangement between the outer part and an intermediate structure’s outward face, and a mechanical suspension arrangement, such as a ball or roller arrangement, between the inner part and an intermediate structure’s inward face.

The inner part, the outer part, or both the inner part and outer part, may be connected to respective inner and outer shafts.

In an aspect, the thermal sensors are arranged in corresponding cavities extending in the radial direction for providing the thermal profile.

The thermal sensors may be more individual sensors or, alternatively, a single unit capable of measuring a thermal profile.

A thermal profile may be used as a basis for extrapolation of the profile. A thermal profile may be extended in one direction, in two directions, or in more directions, e.g. radial directions. An extrapolation may be performed taking thermal properties of the materials into account. The extrapolation may be performed by solving heat diffusion problems. The extrapolation may be performed by solving boundary value problems.

Thus, an axial thermal profile representing a thermal profile in the axial direction may be extrapolated radially from the path of the axial profile along which temperatures are measured. Likewise, an obtained radial thermal profile representing a thermal profile in the radial direction may be extrapolated radially from the path of the radial profile along which temperatures are measured.

Having two or more profiles, interpolation may be performed between the two profiles. Interpolation between two profiles in the axial direction will provide thermal profiles in between, i.e. in the radial direction of the bearing. Likewise, interpolation between two profiles in the radial direction will provide thermal profiles in between, i.e. in the axial direction of the bearing.

As outlined above, each profile may provide boundary conditions at two boundaries, i.e. the respective paths from which the profiles are obtained. Thermal properties may then be estimated in between by interpolation or by solving heat type boundary value problems using analytics models or computer implemented solvers in readily available packages such as CAD-programs, COMSOL Multiphysics, or general FEMimplemented packages.

A person skilled in the art will, according to the bearing at hand, be able to select a suitable thermal sensor according to the temperature range to be measured.

The thermal sensors may be arranged in contact with the outer part, the inner part, or both the outer part and the inner part.

The thermal sensors may be arranged in non-contact with the outer part, the inner part, or both the outer part and the inner part. A thermal sensor may also be an infraredtype of sensor arranged to probe and extract a temperature profile.

In an aspect, the thermal sensors are arranged in the outer part, in the inner part, or both the outer part and the inner part.

A thermal sensor may be inserted into the outer part, into the inner part, or both into the outer part and the inner part.

The thermal sensors may be spatially distributed. The distribution may be homogeneous, i.e. with equal distances between each sensor. The distribution may be inhomogeneous, i.e. with uneven distances between the sensors. Thereby, certain areas or paths may be more densely propped than other areas or paths.

A thermal sensor may be provided in a cavity or hole in the inner part or the outer part. In one embodiment, a cavity may be established in a radial direction. The thermal sensor may be inserted into a hole.

In an aspect, the thermal sensors are arranged in one or more longitudinal rods configured to be inserted in corresponding complementary one or more rod cavities extendDK 179778 B1 ing in the axial direction in the outer part, in the inner part, or both in the outer part and in the inner part.

There may be a hole, a cavity, or a recess in the inner part, the outer part or both the inner part and the outer part. The hole, cavity or recess may extend in the axial direction. The rod may have a substantially complementary cross section to the hole, cavity or recess for the rod to be inserted.

In a particular embodiment, the hole, cavity or recess may be a canal having a curved section. The rod may then be made of a flexible material to be inserted into the canal.

In an aspect, the longitudinal rods comprise multiple sensor holes substantially extending in a transverse direction of the longitudinal rods and being distributed in the longitudinal direction of each longitudinal rod. Each sensor cavity is configured to receive a thermal sensor and the longitudinal rods have a rod recess extending from one end of the longitudinal rod in the longitudinal direction.

In an aspect, the bearing may further comprise a temperature adjustment arrangement arranged to adjust temperature in the axial direction.

The temperature adjustment arrangement may be a cooling system arranged on or in the bearing. The cooling system may be in thermal contact with the outside of the bearing, or the cooling system may be an integral part of the outer part, the inner part, or both the outer and inner part. There may be canals for conducting a coolant.

The temperature adjustment arrangement may be established in zones, where each zone may be cooled individually.

The temperature adjustment arrangement may be a heating system arranged on or in the bearing. The heating system may be in thermal contact with the outside of the bearing, or the heating system may be an integral part of the outer part, the inner part, or both the outer and inner part. There may be canals for conducting heat to the part. There may also be provided means for Joule heating (i.e. ohmic or resistive heating).

In an aspect, the bearing may further comprise or be configured to interact with a controller configured to control the temperature adjustment arrangement as function of the thermal profile.

Thereby, means are provided to operate the bearing as described to mitigate or avoid forces resulting from e.g. expansion or changes in material properties caused by thermal conditions or thermal gradients.

The controller may collect data and provide actions to store data. The controller may be configured to organise data and select data. The controller may be configured with processing means for computational actions such as fault detection, data analysis, averaging or smoothing of data. The controller may be configured to analyse data, produce alerts, and control instructions. The controller may further be configured to or communicate with a dedicated computational system configured to further analyse the one or more thermal profiles to produce simulations or calculations based on one or more thermal profiles.

The outer part and inner part may slightly offset or misalign as a result of thermal conditions. The effect may be mitigated by using the temperature adjustment arrangement.

In an aspect, the controller may further be configured to control the temperature adjustment arrangement as function of a pre-determined thermal profile.

A bearing may be designed or dimensioned to operate under an assumption of predetermined thermal conditions. The design may take into account expansion or changes in material properties at certain thermal conditions.

Thus, a bearing may have been designed to mitigate forces or material properties under certain operational conditions, including thermal conditions. The assumed thermal conditions may then be achieved or at least targeted during real operation, thereby enabling the bearing to operate close to the design or dimensioning.

In an aspect, the controller is further configured to determine a temperature profile in the intermediate structure as a function of the thermal profile.

In an aspect, the bearing may further comprise a brake arrangement, which brake arrangement is configured to engage as function of the thermal profile.

Thereby, the system is enabled to perform corrective measures or actions depending on operational conditions.

A particular object may be achieved by a wind turbine generator comprising a tower, a nacelle rotatably connected to the tower and supporting a rotor that is rotatably supported in a bearing as disclosed herein.

Although, the disclosed bearing is not limited to be used in a wind turbine generator, the size, the forces and a desire to operate a wind turbine generator for as long as possible under the forces and nature of changing wind conditions makes the use of a bearing as disclosed suitable for use in connection with a wind turbine generator.

Irrespective of the general applicability of a bearing as disclosed, then the operational costs and the technical aspects, including maintenance circumstances associated with a wind turbine engine, may justify the outlined alterations. However, a person skilled in the art of bearings will appreciate the principles and advantages and be able to construct a bearing as disclosed or for any other use.

An object may be achieved by a method of operating a bearing with an inner part rotatably arranged relative to an outer part for rotation about an axis, the bearing having multiple thermal sensors arranged in the axial direction. The method may comprise an act of obtaining a thermal profile in the axial direction from the thermal sensors. A further act may be an act of operating the bearing as a function of the thermal profile.

In an aspect, the act of operating the bearing comprises an act of adjusting the temperature in the axial direction.

In an aspect, the method of operating a bearing may further comprise an act of optioning a thermal profile in the radial direction from the thermal sensors.

In an aspect, the method of operating a bearing may further comprise an act of obtaining a pre-determined thermal profile and an act of adjusting the temperature in the axial direction as a function of the pre-determined thermal profile and the obtained thermal profile.

In an aspect, the method of operating a bearing may further comprise acts of:

- estimating a radial temperature profile by means of a computer implemented algorithm as a function of at least one temperature profile in the axial direction, and

- wherein the act of operating the bearing is performed as a function of the estimated radial temperature profile.

An objective may be achieved by a bearing obtained by a process of providing a first version of a bearing with an inner part rotatably arranged relative to an outer part for rotation about an axis and extending in the axial direction. Then, obtaining a temperature profile of the first version of the bearing during operation before providing a second version of the bearing by modifying the first version of the bearing as a function of the obtained thermal profile.

A bearing may be provided by design. The design may be based on geometrical principles. The design may include structural and mechanical loads or stress considerations or analyses. The design may include dynamical aspects. The design may include thermal properties. The design may include operational scenarios. The design may include empirical experience.

To further advance the durability and to mitigate undesired forces and wear and tear, the bearing may also be obtained by a first version of a bearing, which bearing is then monitored as outlined during operation whereby the thermal profile is obtained and used in the design of a second version of the intended bearing.

The thermal profile may be an axial thermal profile, a radial thermal profile, or a combination of both profiles.

A thermal profile may be used as it is. A thermal profile may be used as a boundary condition to estimate thermal conditions at different spatial locations or a temporal development. A person skilled in the art will appreciate a breadth of tools readily available to include the thermal profiles in design. In example, CAD-tools, FEM programs, COMSOL Multiphysics®, or alike software. Also in example, obtained thermal profiles may be used in design processes based on empirical principles.

An object may be achieved by a bearing obtained by a process of proving a bearing with an inner part rotatably arranged relative to an outer part for rotation about an axis and extending in the axial direction. The bearing may be updated by installing multiple thermal sensors in an axial direction in either the inner part, the outer part, or both the inner part and the outer part.

Thereby, performing a modification (by adding material or removing material will mitigate undesired forces or wear and tear. A bearing may be designed and provided as such and then modified. In example, faces or structures (e.g. bodies) may be designed and prepared to be modified. There may be a surplus of material prepared to act as thermal buffers and prepared to be expanded or reduced.

An object may be achieved by a bearing obtained by a process of providing a bearing with an inner part rotatably arranged relative to an outer part for rotation about an axis and extending in the axial direction; the inner part, the outer part, or both the inner part and the outer part, having multiple bolts arranged axially.

The bearing may be updated by removing multiple bolts leaving respective cavities before inserting a thermal sensor in the respective cavities.

The bolt or pin may be as previously outlined and having the stated advantages.

An object may be achieved by a bearing obtained by a process of providing a bearing with an inner part rotatably arranged relative to an outer part for rotation about an axis and extending in the axial direction; the inner part, the outer part, or both the inner part and the outer part, having multiple bolts arranged axially. The bearing may be updated by making multiple cavities in the inner part, the outer part, or both the inner part and the outer part, before inserting a thermal sensor in the respective cavities.

The bolt or pin may be as previously outlined and having the stated advantages.

An object may be achieved by a bearing obtained by a process of providing a bearing with an inner part rotatably arranged relative to an outer part for rotation about an axis and extending in the axial direction; the inner part, the outer part, or both the inner part and the outer part, having multiple bolts inserted in the axial direction. The bearing may be modified by removing one or more bolts leaving respective rod cavities before inserting a longitudinal rod with multiple thermal sensors distributed in the longitudinal direction.

The bolt or pin may be as previously outlined and having the stated advantages.

Description of the Drawing

Embodiments of the invention will be described in the figures, whereon:

Fig. 1 illustrates a wind turbine generator with a bearing as disclosed,

Fig. 2 illustrates a bearing with an outer part and an inner part communicating via an intermediate arrangement with rollers and multiple thermal sensors arranged in the axial direction,

Fig. 3 illustrates a bearing with an outer part and an inner part and multiple thermal sensors arranged in the axial direction,

Fig. 4 illustrates an exemplary bearing supporting a rotor shaft of a wind turbine generator,

Fig. 5 illustrates a rod with a distribution of holes for thermal sensors and for insertion into a bearing,

Fig. 6 illustrates a rod with a distribution of holes or cavities for thermal sensors for obtaining a thermal profile,

Fig. 7 illustrates details of a rod for thermal sensors,

Fig. 8 illustrates a cross-section of a rod with a recess,

Fig. 9 illustrates examples of temporal developments of temperatures of thermal sensors from selected spatial positions,

Fig. 10 continues with examples from fig. 9,

Fig. 11 illustrates thermal profiles of an outer part and an inner part of a bearing,

Fig. 12 illustrates a thermal sensor installed in a rod, and

Fig. 13 illustrates a bearing with a temperature adjustment arrangement.

Detailed Description of the Invention

No	Item
100	Bearing
110	Inner part
112	Inner ring
150	Outer part
152	Outer ring
160	Intermediate communication structure
161	Balls
162	Rollers
200	Axis
210	Axial direction
220	Radial direction
230	Shaft
300	Thermal sensors
301	Thermal sensor
310	Cavities
311	Cavity
312	Cavity distribution
320	Thermal sensor
322	Sensor cable
325	Sensor spring
330	Longitudinal rod
331	Longitudinal direction (of rod)

332	Transverse direction (of rod)
335	Rod cavity
337	Sensor hole
340	Rod recess
350	Bolt/Pin
400	Thermal profile
401	First thermal profile
402	Second thermal profile
410	Axial thermal profile
420	Radial thermal profile
450	Temperature
455	Temporal profile
460	Data validity measure
500	Temperature adjustment arrangement
510	Adjustment Zone
550	Controller
600	Brake arrangement
1000	Wind turbine
1010	Tower
1020	Nacelle
1030	Rotor

Fig. 1 illustrates an exemplary implementation or use of a bearing as will be described in details. Illustrated is a wind turbine generator 1000 comprising a tower 1010, a na5 celle 1020 rotatably connected to the tower 1010 and supporting a rotor 1030 that is rotatably supported in a bearing 100 via a shaft 230 (not shown) defining an axis 200.

Fig. 2 illustrates a general bearing 100 with an outer part 150 and an inner part 110 communicating via an intermediate arrangement or intermediate communication struc10 ture 160 with balls 161 as gliders and multiple thermal sensors 300 arranged in the axial direction 210 parallel with the rotational axis 200. Radially from the axis 200, there is the radial direction 220.

The bearing 100 is connected to a shaft 230 defining the axial direction 210. The shaft 230 is connected to the inner part 110 which here is an inner ring 112 formed with an outward face supporting the balls 161. The outer part 150 is here shown as comprising an extending structure in thermal contact with an inner ring 112 with an inward face supporting the balls 161. Thus, the inner part 110 is rotatably connected to the outer part 150. The outer part 150 could easily be formed to be integral with the outer ring 152.

A set of thermal sensors 300 is distributed in the axial direction 210 and configured to provide a thermal profile 400, which thermal profile will be exemplified in later figures.

In this embodiment, the thermal sensors 300 are arranged in a longitudinal rod 330 inserted into a rod cavity 335 extending in the axial direction 210 of the outer part 150.

In this embodiment, there is a first set of thermal sensors 300 arranged in a radial position resulting in a first thermal profile 401. In a different radial position (e.g. 180 degrees from the first set of thermal sensors 300), there is a second set of thermal sensors 300 arranged to provide a second thermal profile 402.

Not shown here is the embodiment where the thermal sensors 300 are arranged in the inner part 110. Also not shown here is the embodiment where there is a first set of thermal sensors 300 in the outer part 150 providing the first thermal profile 401 and a second set of thermal sensors 300 in the inner part 110 providing the second thermal profile 402.

Fig. 3 illustrates an embodiment of a bearing 100 with an outer part 150 and an inner part 150 and multiple thermal sensors 300 arranged in the axial direction 210.

The outer part 150 may be an outer ring 152 and the inner part 110 may be an inner ring 112.

In this embodiment, thermal sensors 300 are arranged in a longitudinal rod 330 inserted into a rod cavity 335 in the outer part 150.

The inner part 110 supports a shaft 230. Outwardly the inner part 110 is rotatably communicating with the inward face of the outer part 150.

As described in the fig. 2 embodiment, there is a first and second arrangement of thermal sensors 300 providing respective first and second thermal profiles 400.

Fig. 4 illustrates an exemplary embodiment of bearing 100 supporting a rotor shaft 230 as illustrated as part of a wind turbine generator 1000 (not seen in full).

The bearing 100 has an outer part 150 and an inner part 110, which inner part is configured for a shaft 230 (indicated). Between the outer part 150 and the inner part 110 there is an intermediate communication structure 160 constructed based on rollers 162.

In the outer part 150, there is a rod cavity 335 with a received longitudinal rod 330 with holes penetrating the rod radially and forming cavities 310 that here extend radially and prepared for receiving thermal sensors 300 (not shown) before and when the rod is inserted in the outer part 150. The longitudinal rod 330, as will be described, replaces a bolt.

During intended placement of the longitudinal rod 330, the holes form cavities 310 allowing thermal sensors 300 (not shown) to be in thermal contact with the outer part 150, here in the outward radial direction. The configuration is with holes distributed in the rod 330 that results in a cavity distribution 312 for providing a first thermal profile 401 when the thermal sensors are in place.

In the inner part 110, there is a rod cavity 335 with a received longitudinal rod 330 with holes penetrating the rod radially and forming with cavities 310 that here extend radially and prepared for receiving thermal sensors 300 (not shown).

During intended placement of the longitudinal rod 330, the holes form cavities 310 allowing thermal sensors 300 (not shown) to be in thermal contact with the inner part 150, here in the inward radial direction, i.e. towards the axes.

The configuration is with holes in the rod 330 that results in a cavity distribution 312 for providing a second thermal profile 402 when the thermal sensors are in place.

In this embodiment, the first thermal profile 401 and the second thermal profile 402 will have spatial different measuring points on the respective outer part 150 and inner part 110 due to the spatially distribution of the holes forming the cavities 310.

Fig. 5 illustrates a longitudinal rod 330 with a distribution of sensor holes 337 for thermal sensors 330 and for insertion into a bearing 100. The rod 330 obviously has a longitudinal direction and is formed with a rod recess 340 providing a spacing for cables and work. The rod 330 is formed as a bolt or pin 350 with a head.

Fig. 6, 7 and 8 exemplify details of the rod 330 as disclosed in fig. 5. Sensor holes are distributed in the longitudinal direction 331 of the rod. A sensor hole 337 extends from the rod recess 340 in a transverse (radial) direction 332 to the outside of the rod 330 so that a thermal sensor 301 can be inserted and have thermal contact with the inner or outer part when in intended use. The rod recess 340 is seen to provide a spacing that will form a canal when in intended use allowing for cables to reach from individual thermal sensors to the outside of the outer or inner part when in intended use. As seen in fig. 6 and the cross section in fig. 7, the recess penetrates the head of the rod.

Fig. 6 exemplifies an uneven distribution of sensor holes 337, which distribution will result in a cavity distribution 312 which may probe the inner or outer part according to specifics such as a specific construction of the intermediate structure between an inner and outer part.

Fig. 8 details the tip of the rod 330 and details about the holes forming the cavities 311 and the transition to the rod recess 340. In particular, there are two relatively close holes forming two close cavities at the section intended to probe the end or the inner or outer part in the axial direction, thereby enabling to detect temperature gradients from the thermal profile.

To exemplify such specifics, reference is made to figure 4, where a rod 330 of the type illustrated in figs. 5, 6 and 7 is seen as inserted into the inner part 110 and placed in the intended use, albeit in fig. 4 the rod extends from left to right versus right to left in figs. 5, 6, and 7. The cavity distribution 312 with densely placed cavities at the centre is seen to target thermal conditions of the region where the rollers 162 meet. There is a single cavity 301 at each region targeting each of the rollers 162. At the tip of the rod 330 there are two relatively close cavities 311 to detect thermal gradients. At the head end of the rod, cavities 310 are distributed to detect thermal gradients.

Also referring to fig. 4, the rod 330 used in the outer part 150, the rod 330 is seen to have a different spatial distribution of holes resulting in cavity distribution 312 intended to target specifics of the intermediate structure as seen from the outside. At the tip of the rod 330, the spacing is dense to capture thermal gradients. Two relatively close cavities 311 are seen to target each of the outwardly facing ends of each of the rollers 162. Only one cavity 311 is used in the centre area to targeting a less complex area of the outer part 150 or intermediate structure 160.

Thus, a thermal profile 400 in the axial direction can be obtained either from one side only e.g. from the outer part 150 or the inner part 110. Alternatively, a first thermal profile 401 may be obtained from say the outer part 150, and a second thermal profile 402 may be obtained from say the inner part 110. In any case, boundary thermal profiles are provided.

Obviously, variations of the rod 330 as shown can be made or tailored according to the intended use. In particular, a person skilled in the art will be able to tailor the distribution of holes 337 in a rod to target specifics of the inner part, the outer part, as well as the intermediate structure 160.

Fig. 9 exemplifies temperatures from an outer part 150, in particular an outer ring 152, of a bearing in a wind turbine, and fig. 10 exemplifies corresponding temperatures from an inner part 110, in particular an inner ring 112.

Each trace shows the temporal development of a temperature 450 illustrated as an example of temporal developments of temperatures 450 obtained from thermal sensors 300 from select spatial positions according to cavity distributions 312.

Each of the thermal sensors 311 is sampled to generate a temperature time series resulting in a temporal profile 455 for the specific point or location. The time series may be sliced at a specific time and thus resulting in an axial thermal profile 410 as the thermal sensors are distributed axially.

The workings of an individual thermal sensor may be validated, and before using data to contribute to a spatial profile, the individual data may be associated with a data validity measure 460. Each time series are seen to have an associated power spectrum as a measure of data validity. Irregularities in the workings or the functioning of an individual sensor may then be identified in the (frequency) power spectrum. In case of irregularities or malfunctions of any thermal sensor, the irregular or malfunctioning sensor may be disregarded when forming the spatial thermal profile 400.

Fig. 11 illustrates thermal profiles 400 of an outer part 150 and an inner part 110 of a bearing 100. Each of the figures A-E illustrates a thermal profile 400 in the axial direction 210. The upper profile is from an outer part 150 and the lower profile is from an inner part 110. Temperature differences between the thermal profiles 400 of the respective inner and outer parts are indicated as At.

The thermal profiles 400 represent examples of a bearing 100 for a wind turbine generator as outlined in fig. 1 and specifically fig 4. The rotor is to the left and the X-axes are going in the axial direction 210 into the nacelle.

Fig. 11A illustrates presumed (calculated) thermal profiles 401 and 402 according to prior art as simulated/calculated by e.g. FEM-analysis.

Figs. 11B-E summarises trends observed during operation of a bearing 100 over time from an initial phase from start-up (B), during start-up (C-D), and to “steady-state” (E).

First and foremost, the thermal profiles 400B-E are unexpectedly and surprisingly observed to differ from common general knowledge even taking calculations/simulation into account. The profiles B-E clearly differ from profile 400A.

Irrespective of the difference to the presumed profiles 401A, 402A, each measured thermal profile 400 allows for the bearing 100 to be constructed or modified according to the actual profile. Moreover, the measured thermal profiles 400 may be used during operation of the bearing 100. Operation of the bearing or the construction in which the bearing is operating may be as a function of the thermal profile 400. Operation may involve braking, cooling, heating, etc. as a function of a thermal profile 400.

In example, the thermal profiles 400 may be provided by a processor or controller by simple data processing.

It is evident that presumed profiles shown in fig. 11A has a At1 > Δτ2. The assumed profiles are also substantially linear. Contrary to this, fig. 11E indicates that the real thermal profiles during operation are surprisingly different by having ΔΗ approximately equal to Δt2. The thermal profiles are also seen to be curved. The real temperature gradients are thus different from the assumed. Taking the real temperatures and temperature gradients into account will allow the forces or loads between the rollers and respective inner and outer faces to be mitigated, reduced or even eliminated.

Fig. 12 illustrates a thermal sensor 301 installed in a sensor hole 337 in a rod 330 for forming a cavity 311 when installed. The sensor hole 337 and sensor 301 are complementary in shape for the sensor 301 to be glided into the sensor hole 337. There is a sensor spring 325 for proving pressure to ensure thermal contact between the sensor 301 and the inner or outer part when the rod 330 is installed as intended. The sensor 301 has a sensor cable 322 for transmitting sensory output. The sensor cable 322 is well placed and protected in the rod recess340 and directed towards the head (not shown) of the rod.

In this particular example of a rod and a thermal sensor, the rod is polymer-based. The rod may easily be constructed as a GIC (Glass-Ionomers Cement) and the sensor is a

PT100-type of thermometer i.e. a resistive temperature sensor based on platinum.

Fig. 13 illustrates a bearing 100 with a temperature adjustment arrangement 500. The temperature adjustment arrangement 500 is in thermal contact with the outer part 150. The temperature adjustment arrangement 500 is controlled by a controller 550 arranged to control temperatures in one or more adjustment zones 510 as a function of one or more thermal profiles 400, which here is obtained from a first thermal profile 10 401 from the outer part 150 from a rod 330 inserted in a rod cavity 335 with thermal sensors distributed in the axial direction 210. A second thermal profile 402 from another area of the outer profile 150 (180-degrees turn) in the same vain.

The temperature adjustment arrangement 500 may be cooling channels circulating 15 radially in each zone 510.

Claims

Bearing (100) with an inner part (110) rotatably arranged relative to an outer part (150) for rotation about an axis (200) and extending in the axial direction (210), the bearing (100) having several thermal sensors (300) disposed in the axial direction (210) and configured to provide a thermal profile (400) in the axial direction (210).

The bearing (100) of claim 1, wherein the thermal sensors (300) are disposed in corresponding holes (310) extending in the radial direction (220).

Bearing (100) according to one or more of the preceding claims, wherein the thermal sensors (300) are arranged in the outer part (150), in the inner part (110), or both in the outer part (150) and the inner part (110).

Bearing (100) according to one or more of the preceding claims, wherein the thermal sensors (300) are arranged in one or more longitudinal rods (330) configured to be inserted into correspondingly complementary one or more rod cavities (335), which extends in the axial direction (210) in the outer part (150), in the inner part (110), or both in the outer part (150) and the inner part (110).

The bearing (100) of claim 4, wherein the one or more longitudinal rods (335) comprises a plurality of sensor holes (337) extending substantially in a transverse direction of the longitudinal rods (330) and distributed longitudinally (331). ) of each longitudinal rod (330); each sensor hole (311) is configured to receive a thermal sensor (301); and wherein the longitudinal rods (330) have a rod recess (340) extending from one end of the longitudinal rod (330) longitudinally.

A bearing (100) according to any one or more of the preceding claims, further comprising intermediate communication structure (160) between the inner part (110) and the outer part (150), which intermediate communication structure (160) comprises several rollers (162) placed in rolling contact with the inner part (110) and the outer part (150).

A bearing (100) according to any one or more of the preceding claims, further comprising a temperature adjusting device (500) adapted to adjust the temperature in the axial direction (210).

The bearing (100) of claim 7, further comprising a controller (550) configured to control the temperature adjusting device (500) as a function of the thermal profile (400).

The bearing (100) of claim 8, wherein the controller (550) is further configured to control the temperature adjusting device (500) as a function of a predetermined thermal profile (400A).

The bearing (100) of claim 8 or 9, wherein the control (550) is further configured to determine a temperature profile in the intermediate structure (160) as a function of the thermal profile (400).

A bearing (100) according to any one or more of the preceding claims, which bearing (100) further comprises a braking device (600), which braking device (600) is configured to engage as a function of the thermal profile (400).

A wind turbine generator (1000) comprising a tower (1010), a nacelle (1020) rotatably connected to the tower (1010) and supporting a rotor (1030) rotatably supported in a bearing (100) according to any preceding claim.

A method of controlling a bearing with an inner portion (110) rotatably disposed relative to an outer portion (150) for rotation about an axis (200), the bearing (100) having a plurality of thermal sensors (300) disposed in the axial direction (210); wherein the method comprises actions of:

obtaining a thermal profile (400) in the axial direction (210) from the thermal sensors (300),

- control of the bearing (100) as a function of the thermal profile (400).

The method of controlling a bearing (100) according to claim 13, wherein the act of controlling the bearing comprises an act of:

adjusting the temperature in the axial direction (210).

The method of controlling a bearing (100) according to claim 14, further comprising the actions of:

obtaining a predetermined thermal profile (400A),

adjusting the temperature in the axial direction (210) by means of a temperature adjusting device (500) as a function of the predetermined thermal profile (400A) and the obtained thermal profile (400).

The method of controlling a bearing (100) according to claim 15, further comprising the actions of:

estimating a radial thermal profile (420) by means of a computer-implemented algorithm as a function of at least one axial thermal profile (410) in the axial direction, and

wherein the act of guiding the bearing (100) is performed as a function of the estimated radial thermal profile (420).

A method of controlling a wind turbine generator (1000) comprising a tower (1010) and a nacelle (1020) rotatably connected to the tower (1010) and supporting a rotor (1030), the method comprising operations of using a bearing (100) supporting the rotor (10) and whose bearing (100) is according to one or more of claims 1 to 11.