Large roller bearing and method and device for monitoring such a large roller bearing

Abstract

The present invention relates to a method for monitoring a roller bearing, in particular in the form of an open-centre large roller bearing, which two is determined by at least one roller bearing row between the bearing rings, wherein different rotational positions of the bearing rings with respect to one another, and different load states in each rotational position, are specified by a control device and rotational-angle-specific and load-specific divergence angles are determined in each case by means of the sensor system in the different rotational positions for the different load states, wherein the determined rotational-angle-specific and load-specific divergence angles are compared with one another by an evaluation device and based on the comparison of the divergence angles a state of wear and / or a remaining service life of the roller bearing is determined.

Description

[0001] Large-diameter rolling bearings and method and device for monitoring such a large-diameter rolling bearing

[0002] The present invention relates to a rolling bearing, in particular in the form of a center-free large rolling bearing, as well as a method and a device for monitoring such a rolling bearing, wherein a gap angle and, if necessary, additional axial and / or radial play between the bearing rings of the rolling bearing are determined by means of a sensor system.

[0003] Slewing bearings have diameters of more than half a meter and are regularly much larger, for example with diameters of more than one meter or more than 1.5 meters, and tend to twist under the naturally very high loads they are subjected to, which is even more severe with a center-free design. Such twisting is caused by loads that are uneven across the circumference, but above all by bending loads that are introduced into the rolling bearing, for example when the slewing bearing supports the superstructure of a construction machine or a crane and high bending moments are introduced into the bearing via the cantilevered machine arm or crane boom, or when corresponding bending moments are introduced into the bearing by the rotor blades of a wind turbine when the latter mounts the adjustable rotor blade on the hub or supports the nacelle of the wind turbine.

[0004] If the rings of the rolling bearings gap apart and spread at a gaping angle, this leads to a massive reduction in bearing service life. This gaping causes a shift in the contact point of the respective rolling element with the raceway. This shift in the contact points leads to an increase in load peaks, as the raceway no longer conforms precisely to the rolling element in the desired manner, thus reducing the service life of the bearing. Therefore, the frequency of gaping and, in particular, the magnitude of the gaping angle can be used to determine excessive bearing loading, and thus to estimate wear or the remaining service life.

[0005] Various monitoring systems with diverse sensor types have already been proposed for monitoring slewing bearings. For example, document EP 1 528 356 B1 describes a non-contact monitoring system that uses two distance sensors to measure the axial and radial clearance between the bearing rings and then determine the tilting clearance between the bearing rings. Two distance sensors are used, one of which faces a radial surface in the axial direction, and the other faces a wedge-shaped circumferential surface in the radial direction.

[0006] Further monitoring devices which use contactless sensors to detect axial bearing movements on the one hand and radial bearing movements on the other hand and compare these with limit values ​​in order to detect excessive bearing wear are known, for example, from the documents US 5,955,880 B1, US 5,336,996 B1 and DE 101 07 067 A1.

[0007] While these existing monitoring systems can detect increased bearing clearance quite accurately, they have relatively little difficulty distinguishing between normal, uniform wear on the one hand and atypical, uneven wear on the other, and predicting the actual remaining service life with at least some accuracy. In particular, the existing systems cannot detect and estimate the bearing impairments associated with gaping of the bearing rings with sufficient precision.

[0008] The present invention is therefore based on the object of creating an improved rolling bearing, an improved method, and an improved device for monitoring the same, each of the type mentioned above, which avoid the disadvantages of the prior art and advantageously develop the latter. In particular, the aim is to create more precise and differentiated monitoring of bearing deformations and their impact on bearing wear without requiring excessively complex tests and sensor systems.

[0009] The stated object is achieved by a method according to claim 1, a device according to claim 6 and a rolling bearing according to claim 7. Preferred embodiments of the invention are the subject of the dependent claims.

[0010] According to a first aspect, it is therefore proposed to move the rolling bearing into various defined rotational positions and to subject it to different load conditions there, and to determine the resulting gap angles. According to the invention, a control device predetermines various rotational positions of the bearing rings relative to one another and different load conditions in each rotational position. By means of the sensors, rotational angle and load-specific gap angles are determined in the various rotational positions for the various load conditions. An evaluation device compares the determined rotational angle and load-specific gap angles with one another, and based on the comparison of the gap angles, a wear condition and / or a remaining service life of the rolling bearing is determined.

[0011] By considering different rotational positions and different specified load conditions in the various rotational positions, uneven gaping and thus atypical, uneven wear can be more precisely determined and better differentiated from normal, uniform wear. At the same time, by determining the gap angles in the various rotational positions based on the gap angle size, it is possible to better estimate the unusual load peaks the bearing rings are subjected to and the degree of wear they exhibit.

[0012] The control device can preferably be designed to predetermine at least one radial load state and at least one tilting load state with the various rotational positions. In the radial load state, the rolling bearing is specifically subjected to a radial load which acts on the rolling bearing essentially perpendicular to the axis of rotation of the rolling bearing or attempts to displace the bearing rings against one another in the radial direction. Advantageously, the said radial force or radial load can be the only load in the radial load state, or more precisely, essentially the only load acting on the bearing in addition to the installation-related bearing loads. Depending on the installation state, the rolling bearing has to carry loads typical for installation, for example the weight of an installation environment supported by the rolling bearing, such as the weight of the superstructure of a construction machine or a crane, which can also be subjected to loads when idling or running.The rolling bearing and its mounting environment are stationary. In the specified radial load condition, the aforementioned radial load is applied to the bearing in addition to these installation-related loads, allowing the sensors to specifically measure any relative movement of the bearing rings to one another as a result of this additional radial load.

[0013] Similarly, in the specified tilting load condition, a targeted tilting moment is applied to the rolling bearing, whereby here too the said tilting moment can preferably be the only additional load in addition to the installation-related bearing loads.

[0014] Preferably, the control device specifies the aforementioned radial load and tilting load conditions online, so to speak, while the bearing is installed in its intended installation environment. In particular, the additional radial load and the additional tilting moment can be generated in machine movements or operations specified by the control device. If the rolling bearing is used, for example, as a rotary bearing in a construction machine that supports the uppercarriage of the construction machine, the undercarriage of the undercarriage can be blocked or braked and the uppercarriage can be subjected to a targeted horizontal force. If the construction machine is an excavator, for example, the crawler track or the wheeled track can be braked and the excavator bucket can be embedded in the ground or anchored to it, and propulsion can be generated by operating the excavator arm, so that the uppercarriage and undercarriage are displaced relative to one another in a horizontal direction.

[0015] To impose the additional tipping moment for the specified tipping load condition, a predetermined weight can be attached to the cantilevered machine arm, for example, or a predetermined load can be suspended or lifted from the boom of a crane. It may also be sufficient to place the machine arm, such as an excavator arm, in a cantilevered position so that the dead weight of the cantilevered machine arm applies a corresponding tipping moment to the rolling bearing.

[0016] In a further development of the invention, the gap angles determined in the various rotational positions under different load conditions can be compared in different and / or multiple ways against each other and / or with reference values ​​for this purpose in order to be able to draw conclusions about the wear state or the remaining service life. In particular, for example, the gap angles recorded in the various rotational positions under the specified radial load condition can be compared with each other. If, for example, a significantly higher gap angle occurs in one rotational position than in the other rotational positions, even though the same radial load was applied, this can be inferred from atypical, uneven wear.

[0017] To the extent that the mounting environment may have different stiffnesses, it is advisable to consider their influence during the aforementioned adjustment, for example, by adapting the reference values ​​for the gap angle, e.g., in the form of permissible maximum values, to the stiffness of the mounting environment or taking this into account. This can be achieved, for example, by deducting or adding to standard values ​​for the reference values ​​that take the mounting environment into account. If, for example, the bearing is mounted rigidly on all sides, so that the mounting environment mitigates torsion of the bearing rings under one-sided loads, the standard reference value for a critical gap angle can be reduced by a deduction of, for example, 25% or 33%, since a smaller gap angle should result in such an installation situation, as long as the bearing itself is intact. Conversely, an unstable or flexible mounting environment can be considered in the opposite way.

[0018] Alternatively or additionally, the reference values ​​can be adapted to partially different installation environments, e.g., to installation environments with different stiffnesses in different directions or in different sections. For example, if the gap angles are determined in different rotational positions with respect to which the installation environments have different stiffnesses, the reference values ​​for the different rotational positions can be adapted accordingly, e.g., reduced for positions with high ambient stiffness and increased for positions with low ambient stiffness.

[0019] In a similar way, the gap angles determined in the various rotational positions under the tilting load conditions can be compared against each other. If a significantly increased gap angle occurs in one or, for example, two rotational positions, even though the same tilting load was applied in the other rotational positions, this can also be indicative of atypical, uneven wear. Alternatively or additionally, the recorded gap angles can also be compared with predetermined reference values. Here, too, the reference values ​​can be adapted to the installation environment or take this into account, as just mentioned. If uneven or excessive deviations of the folding angle from the respective reference value occur, this can be indicative of atypical wear. The comparison of the gap angles against each other can be combined with comparison against reference values, e.g.Such that, if the reference values ​​are clearly adhered to, larger deviations from each other are still tolerated, and vice versa. On the other hand, atypical wear can be inferred even if the adjustments are still permissible per se, but both times are close to the permissible limits. By taking the adjustments into account, an overall more refined determination of atypical wear can be achieved.

[0020] Alternatively or additionally, however, the gap angles in the radial load condition on the one hand and in the tilting load condition on the other hand can also be compared against each other and / or against reference values ​​in the individual rotational positions in order to determine whether the deviation of the gap angles under different load conditions in one or the other rotational position exceeds a predetermined threshold value, so that an excessive deviation of the gap angle can be used to infer atypical wear.

[0021] Alternatively or additionally, it can also be checked whether the deviations in the gap angles, determined under the radial load condition on the one hand and the tilting load condition on the other, deviate to different degrees from each other and / or from reference values ​​in the various rotational positions. If, for example, a significantly larger or significantly smaller deviation is observed in one or two rotational positions than in the other rotational positions, this may indicate increased wear or a shortened remaining service life.

[0022] In a further development of the invention, the sensor system can be used to determine not only the gap angle between the bearing rings, but also the axial and / or radial clearance between the bearing rings, or axial and / or radial movements, in the various rotational positions when the rolling bearing is subjected to different load conditions in the aforementioned manner in the various rotational positions. The evaluation device can be configured to take into account, in addition to the gap angle, the determined axial and / or radial clearances specific to the rotational angle and load condition when determining the remaining service life or the wear condition.

[0023] This can be taken into account in various ways. For example, the axial and / or radial clearances specific to the angle of rotation and load condition can be used as an independent criterion for determining excessive wear or a reduced remaining service life, independent of the gap angle. For example, axial clearances recorded in the various specified rotational positions can be compared with each other, and if excessive axial clearance occurs in one rotational position or if the axial clearance in one rotational position deviates excessively from the axial clearances in the other rotational positions, increased wear or a reduced remaining service life can be concluded. The radial clearances specific to the angle of rotation and load condition can be evaluated in a similar way.

[0024] The axial and / or radial clearances in the various rotational positions and load conditions can also be taken into account in conjunction with the determined gap angles to determine the wear level and remaining service life. For example, an increased wear level or a shortened remaining service life can be assumed if, in one of the specified rotational positions, not only the gap angle occurring there and / or its deviation from the gap angles in other rotational positions exceeds or falls below a predetermined threshold, but also at least the axial clearance occurring in the specified rotational position and / or the radial clearance determined there and / or its deviation from the radial and / or axial clearances occurring in the other rotational positions exceeds or falls below a predetermined threshold.

[0025] The sensors used to determine the gap angle and / or the axial and / or radial clearances or movements can be designed in a variety of ways. For example, distance sensors can be used to determine the size of a bearing gap between the bearing rings at various locations. Based on the gap widths determined by the distance sensors at predetermined sections of the bearing gap and the known geometry of the bearing rings, the tilt angle can be determined, or the axial and / or radial clearance can be determined.

[0026] According to a further aspect of the invention, the sensor system can also comprise a plurality of inclination sensors, wherein at least one inclination sensor is attached to each of the bearing rings and the evaluation device is designed to determine the gap angle from the inclination signals of the inclination sensors determined on both bearing rings. In particular, the gap angle can be calculated from a difference between the inclination angles that have been detected on the two bearing rings by the inclination sensors attached there. If it is assumed that the bearing rings do not gape apart, but are exactly concentric to one another as intended or show no spreading, it can be assumed that the bearing rings adopt the same inclination in space. If the bearing rings or certain sections of the bearing rings have different orientations in space orInclinations relative to the vertical or relative to the horizontal, it can be assumed that the different orientations or inclinations are caused by gaps.

[0027] In a further development of the invention, several inclination sensors can be attached to at least one or each of the bearing rings. These sensors can be arranged in different sectors or distributed around the circumference in order to determine the inclination in different bearing ring sectors. By detecting the bearing ring inclination sector by sector, deformations can be detected particularly precisely, and gap angles that occur differently in different sectors can be accurately detected. Furthermore, it can also be ensured in different rotational positions that an inclination sensor is present in a bearing ring sector that is expected to exhibit the largest gap angle, in order to precisely measure the inclination there.

[0028] The recorded inclinations in the different sectors of a bearing ring can be compared with each other or the gap angles in neighboring or adjacent sectors of different bearing rings can be compared with each other in order to, for example, reduce the remaining service life or assume an increased level of wear if a threshold value is exceeded.

[0029] Alternatively or additionally, according to a further aspect of the invention, the sensor system can also comprise one or more triangulation sensor units which determine the gap angle of a bearing gap between the two bearing rings by triangulation of a measuring signal.

[0030] For example, such a triangulation sensor unit can have two signal emitters and two signal receivers, with each of the two signal emitters mounted on one of the bearing rings and projecting a signal onto a contour of the other bearing ring on the other side of the bearing gap. The signal receivers are also mounted on one of the bearing rings and can receive the signal transmitted or returned or reflected by the opposite bearing ring and determine its direction and / or point of incidence in order to determine the gap angle between the two bearing rings from the two signal angles by triangulation.

[0031] In particular, two emitter-receiver sensor pairs can be mounted on a bearing ring and two signals can be directed to an opposite contour of the other bearing ring on the opposite gap side and the respective reflected or returned signal can be received and the signal angle between the emitted signal and the reflected signal can be determined, so that the gap angle can be determined from the possibly different signal angles.

[0032] Preferably, the opposite contour of the other bearing ring, onto which the signal is projected and from which it is reflected, has an arcuate contour, for example, a circular arc, a cylindrical contour, and / or a spherical cap contour, although other contours such as elliptical contours are also possible. The signal emitters can be aligned such that they emit essentially parallel signals with a transverse offset and thus project them onto different sections of the arcuately contoured reflection contour. Depending on the gap between the bearing rings, different, significantly different signal angles result between the emitted signals and the reflected signals. The gap angle can then be determined from these signal angles.

[0033] Such a triangulation sensor unit can be installed very space-efficiently and does not require separate, widely spaced installation locations for different sensors. Nevertheless, the gap angle can be determined very precisely.

[0034] The invention is explained in more detail below with reference to preferred embodiments and the accompanying drawings. In the drawings:

[0035] Fig. 1: a rolling bearing with a monitoring device according to an advantageous embodiment of the invention, wherein different rotational positions and bearing loads for the rolling bearing can be specified by a control device and load-specific gap angles are determined in the different rotational positions by means of a sensor system,

[0036] Fig. 2: a half-section through the rolling bearing from Fig. 1 , showing the gap angle between the two bearing rings and the sensors attached to the bearing rings in the form of inclination sensors,

[0037] Fig. 3: a half-section through the rolling bearing from Fig. 1, showing the gap angle between the two bearing rings as well as the sensor system for determining the gap angle in the form of a triangulation sensor unit, wherein the triangulation sensor unit is additionally shown in an enlarged, partial view in order to more clearly show the paired signal emitters and signal receivers,

[0038] Fig. 4: a half-section through the rolling bearing from Fig. 1, showing the gap angle between the two bearing rings and the sensor system in the form of two distance sensors, by means of which the gap angle can be determined, Fig. 5: a representation of the screen control of the control device for specifying various rotational positions when determining the gap angle, wherein the partial view a) specifies a rotational position of 0° and the partial view b) specifies a rotational position of 180°, and

[0039] Fig. 6: a menu display of the control device for specifying the bearing load conditions for the gap angle determination, wherein partial view a) specifies a tilting and axial load condition and partial view b) specifies a radial load condition.

[0040] As Figures 5 and 6 show, the rolling bearing 1 can, for example, form the slewing gear bearing of a construction machine, for example in the form of an excavator, whereby the slewing gear bearing can support the uppercarriage or slewing platform of the construction machine on its undercarriage so that it can rotate about an upright axis of rotation. In the case of the excavator, the undercarriage is equipped with a crawler track, and the rotating uppercarriage carries an articulated boom with an excavator bucket.

[0041] The aforementioned rolling bearing 1 can be designed in the form of a centerless large rolling bearing, wherein one of the two mutually rotatable inner and outer rings 2, 3 can be provided with a toothing 20 in order to be able to be rotated relative to the other ring by a slewing gear drive (not specifically shown), see Figures 2 to 4.

[0042] The inner and outer rings 2, 3 are rotatably supported against each other by one or more rows of rolling bearings, wherein, for example, two axial bearing rows 5, 6 and one radial bearing row 4 can be provided between the inner and outer rings 2, 3, see, for example, Figure 2. The aforementioned axial and radial bearing rows 4, 5, 6 can, for example, be arranged in the bearing gap around an annular nose, with which one of the bearing rings can engage in an annular groove of the other bearing ring, see Figure 2. For example, two axial bearing rows 5, 6 can be supported on opposite, radially extending flanks of the annular nose 21, while the radial bearing row 4 can be arranged on the circumferential surface of the annular nose 21 between the two axial bearing rows 5, 6, see Figure 2.

[0043] As Figure 2 shows, large loads, for example in the form of tilting moments and / or axial loads unevenly distributed across the circumference, and possibly also exacerbated by wear, can lead to bearing ring deformations or tilting, resulting in a gap angle ß between the inner ring 2 and the outer ring 3 (see Figures 2 to 4). The gap angle ß describes the spread angle between two opposing circumferential surfaces of the inner and outer rings 2, 3, which should be coaxially aligned with one another and each extend parallel to the axis of rotation. For example, the gap angle ß can be observed at an axial end section of the bearing rings 2, 3, where an outer circumferential surface of the inner ring 2 and an inner circumferential surface of the outer ring 3 are opposite one another (see Figure 2).

[0044] While Figure 2 only shows an example, it should be clarified that the inner and outer rings 2, 3 can also be interchanged, ie, in a different bearing design, 2 would be the outer ring and 3 the inner ring. Accordingly, the arrangement of the sensor components described below could be reversed, ie, a component described on the outer ring could be on the inner ring, and a component described on the inner ring could be on the outer ring.

[0045] The gap angle β mentioned could, however, also be observed on an opposite side of the bearing rings, for example, the upper edge section side according to Figure 2, although this would be more difficult because the bearings there are pushed together or tilted closer to one another. Looking at Figure 2, for example, the gap angle β mentioned could also be observed between two opposite, at least approximately radially extending annular surfaces of the inner and outer rings 2, 3, for example, between the raceways of the axial bearing rows 5, 6. As Figure 2 shows, the two raceways of the inner ring 2 for the two axial bearing rows 5, 6 gap open compared to the two raceways of the axial bearing rows 5, 6 provided on the ring nose 21 of the outer ring 3. Analogously, the gap angle β mentioned can also be observed on the approximately circumferentially extending or axially extending raceways of the radial bearing row 4, see Figure 2.

[0046] The gap angle ß is a measure of the unwanted or unnatural tilting or slanting of the mating raceway surfaces of a bearing row. This results in the rolling elements no longer having the predetermined contact points or contact lines with the raceways, as the contact point is shifted by the gap angle ß. For example, if one considers Figure 2, the upper and lower axial bearing rows 5 and 6, the gap angle ß causes edge wear on the essentially cylindrical rolling elements. Edge wear also occurs in radial bearing row 4 due to the gap angle ß.

[0047] However, such a displacement of the contact point does not only occur with flat raceways or cylindrical rolling elements, but can also occur with curved raceways of, for example, spherical roller bearings or ball bearings, or with tapered roller bearings and the raceways that are tapered to one another.

[0048] To determine the gap angle ß, a sensor system 8 is provided, which preferably comprises several sensor elements that can be distributed around the circumference of the bearing rings in different sectors, see, for example, Figure 1, in which a total of four sensor elements are arranged in opposing sectors. However, sensors can also be arranged in, for example, four opposing quadrants in order to determine deformations or gap angles even more precisely.

[0049] As Figure 2 shows, the sensor system 8 can have inclination sensors 17, 18 as sensor elements, which can detect the absolute inclination in space and / or determine an inclination relative to one another. Preferably, at least one of the inclination sensors 17 is attached to the inner ring 2 and one of the inclination sensors 18 to the outer ring 3, see Figure 2, wherein, for example, one of the said inclination sensors can be attached to a circumferential surface and one of the inclination sensors can be attached to an axial surface of the bearing rings. Preferably, one of the sensors can be attached to the circumference and one of the sensors to the end face, but it is also possible for one sensor to be attached to the inner circumference and one sensor to the end face of each of the inner and outer rings 2, 3, see Figure 2, where the additional inclination sensors are shown in dashed lines. The said inclination sensors 17, 18 determine the respective inclination θ1 or02 of the inner ring 2 on the one hand and the outer ring 3 on the other hand, so that by adjusting, in particular by calculating the difference between the measured inclinations 01 and 02, the gap angle ß can be determined.

[0050] As Figure 3 shows, the sensor system 8 - alternatively or in addition to the inclination sensors 17, 18 - can also have one or more triangulation sensor units 19 distributed over the circumference, which determine / determine the gap angle ß between the inner and outer rings 2, 3 by triangulation.

[0051] As the enlarged detailed view of Figure 3 clearly shows, each of the triangulation sensor units 19 can have two transmitting or signal emitters S1, S2, each of which transmits a signal from one of the bearing rings and projects it onto an opposite surface of the other bearing ring. For example, both signal emitters S1, S2 can be arranged on the same bearing ring, for example on the inner ring 2, and project the signal onto the other bearing ring, for example the outer ring 3. The signal emitters S1, S2 can be arranged, for example, such that they radiate their signals in a radial direction—without a gaping angle.

[0052] The opposite contour surface of the other bearing ring, which according to Figure 3 is the outer ring 3, can preferably be curved, in particular have a curved contour when viewed in cross-section. As Figure 3 shows, in particular a concavely curved contour when viewed in cross-section can lie opposite the two signal emitters S1, S2, wherein the curved counter-contour 22 can extend continuously, for example, in the form of an annular groove in one of the bearing rings, for example the outer ring 3, wherein said annular groove can have a circular or circular arc-shaped contoured base.

[0053] The signal thrown by the signal emitters S1, S2 onto the counter contour 22 is reflected by the counter contour 22 and received by the signal receivers E1, E2 of the triangulation sensor unit 19, whereby depending on the tilting of the bearing rings relative to one another, the point of impact moves, so to speak, or a different signal angle θ1, θ2 is established, see Figure 3. The gap angle β can be determined from the signal angles θ1 and θ2 determined by the triangulation sensor unit 19.

[0054] As Figure 4 illustrates, the sensor system 8 can also comprise contactless distance sensors 23, 24 - alternatively or in addition to the inclination sensors 17, 18 and / or the triangulation sensor unit 19, see Figure 4.

[0055] Advantageously, the aforementioned distance sensors 23, 24 can measure the distance between the two bearing rings 2, 3 in the region of the bearing gap, wherein, for example, both distance sensors 23, 24 can measure a radial distance between the bearing rings 2, 3, advantageously in regions spaced apart from one another in the axial direction, for example once beneath all bearing rows and once in the region between an upper and a second uppermost bearing row, see Figure 4.

[0056] Due to the gap angle ß, the inner and outer rings 2, 3 shift from each other, so that the radial gap changes differently at different points, for example, under the bearing rows by the dimension d2 and in the upper area by the dimension d1. The gap angle ß can be determined from the radial distances d1, d2 that arise and the known bearing geometry.

[0057] It would also be conceivable, alternatively or in addition to the radial distance sensors shown, to measure the axial distance between the bearing rings at characteristic points of the bearing gap, depending on the design of the bearing gap geometry.

[0058] As Figure 1 illustrates, several sensor elements 13, 14, 15, 16 can be arranged distributed over the circumference in different sectors or quadrants of the inner and outer rings 2, 3 in order to be able to determine the gap angle ß from the different inclination and / or triangulation and / or distance signals in the different sectors or quadrants.

[0059] In this case, a control device 9 (see Figure 1 and Figures 5 and 6) specifies different rotational positions of the bearing rings 2, 3 relative to one another and different load conditions in each rotational position, and by means of the sensor system 8 in the different rotational positions, the respective rotational angle and load-specific gap angle ß are then determined for the different load conditions.

[0060] As Figure 5 illustrates, for example, the control device 9 can specify different rotational positions of the rolling bearing 1 on a display 25, for example by indicating the rotational position by angle indications of 0° and 180° and / or by specifying it by a pictorial representation of the working device or the machine, for example by displaying the position of the machine boom.

[0061] The respective rotational position of rolling bearing 1 can then be reached automatically, for example, by tapping the display or by manually operating control elements such as a joystick. In the example shown in Figure 5, the "Apply" button on the touchscreen can be pressed.

[0062] To implement the various load conditions of the rolling bearing in the respective rotational position, the control device 9 can specify corresponding machine positions and / or configurations. In the example of the excavator, for example, to implement a tipping moment on the slewing gear bearing, an approximately horizontally projecting position of the bucket arm can be specified, see Figure 6a. To implement a radial load on the slewing gear bearing, the excavator bucket can be embedded in the ground or anchored to it and simultaneously the undercarriage drive can be actuated, for example by reversing. Conversely, the undercarriage can also be braked and the excavator bucket actuated to pull the machine forward, so that the braked undercarriage elements result in a radial reaction load on the slewing gear bearing, see Figure 6b.

[0063] Here, too, the control device 9 can operate semi-automatically or fully automatically. For example, after displaying the respective load situation according to Figure 6a or 6b, the "Apply" button shown on the touchscreen can be pressed to implement the load.

[0064] At the same time, the control device 9 establishes the data acquisition by the sensor system 80, see Figure 1 .

[0065] The data acquired by the sensor system 8 and / or the resulting gap angle ß can be displayed and / or forwarded via a user interface, for example, in the form of a tablet or a display in the machine control system or a mobile phone, and / or forwarded, for example, to a data storage device. After data evaluation, a warning signal can also be issued if the remaining service life has become dangerously short or a certain level of wear has occurred.

Claims

Claims 1 . Method for monitoring a rolling bearing (1), in particular in the form of a center-free large rolling bearing, which is determined by at least one row of rolling bearings (4, 5, 6) between the bearing rings (2, 3), characterized in that different rotational positions of the bearing rings (2, 3) relative to one another and different load conditions are specified in each rotational position by a control device (9), and by means of the sensor system (8) in the various rotational positions for the various load conditions, respective rotational angle and load-specific gap angles (ß) are determined, wherein an evaluation device (10) compares the determined rotational angle and load-specific gap angles with one another and / or with at least one predetermined reference value and, based on the comparison of the gap angles (ß), a wear condition and / or a remaining service life of the rolling bearing (1) is determined.

2. Method according to the preceding claim, wherein the control device (9) predetermines, in each of the predefined rotation angle positions, a radial load state in which the rolling bearing (1) is loaded with a predetermined radial load, preferably substantially exclusively with a radial load in addition to the bearing loads caused by installation, substantially perpendicular to the rotation axis (11) of the rolling bearing (1), and furthermore a tilting load state in which the rolling bearing is loaded with a tilting moment, preferably substantially exclusively with a tilting moment in addition to the bearing loads caused by installation, about a tilting axis (12) transverse to the rotation axis (11) of the rolling bearing (1), and the sensor system (8) determines, in each rotation position, on the one hand, a gap angle (ßr) in the radial load state and a gap angle (ßk) in the tilting load state, wherein the evaluation device (10) determines the gap angles (ß r) in the radial load conditions in the various rotational positions are compared with one another and / or with at least one radial load reference value, and the gap angles (ßk) under the tilting load conditions in the various rotational positions are compared with one another and / or with at least one tilting load reference value, and optionally additionally the gap angles (ßr, ßk) under the radial and tilting load conditions in each rotational position are compared with one another and / or with at least one reference value, and the wear condition and / or the remaining service life of the rolling bearing (1) is determined on the basis of the comparison.

3. Method according to one of the preceding claims, wherein the evaluation device (10) compares the determined angle of rotation and load-specific gap angles with a plurality of reference values ​​which comprise different reference values ​​for different angles of rotation and / or different reference values ​​for different load conditions, and based on the comparison of the gap angles (ß) a wear condition and / or a remaining service life of the rolling bearing (1) is determined.

4. Method according to one of the preceding claims, wherein the evaluation device (10) compares the determined angle of rotation and load-specific gap angles both with each other and with angle of rotation and load-specific reference values ​​are compared and a wear condition and / or a remaining service life of the rolling bearing (1) is determined on the basis of the comparisons of the gap angles (ß), wherein the evaluation device (10) takes into account an interaction of the comparison of the angle-of-rotation and load-specific gap angles with one another and the comparison of the angle-of-rotation and load-specific gap angles with angle-of-rotation and load-specific reference values ​​in such a way that, with regard to the determination of the wear condition, smaller or good deviations in one comparison compensate for or mitigate larger or bad deviations in the other comparison.

5. Method according to one of the preceding claims, wherein the sensors determine, in addition to the gap angles mentioned, rotation angle and load-specific axial and / or radial play between the bearing rings in the various rotational positions for the various load conditions, wherein the evaluation device (10) compares the determined axial and / or radial play with one another and, based on the comparison of the gap angles and the axial and / or radial play, the wear condition and / or the remaining service life of the rolling bearing (1) is determined.

6. Method according to the two preceding claims, wherein the axial play and the radial play in the radial load state and the axial play and the radial play in the tilting load state are determined by the sensor in each rotational position, wherein the evaluation device (10) compares the axial plays under the radial load state in the various rotational positions with one another and the radial plays under the radial load state in the various rotational positions with one another, and the axial plays under the tilting load state in the various rotational positions are compared with one another and the radial plays under the tilting load state in the various rotational positions are compared with one another, and the wear state and / or the remaining service life of the rolling bearing (1) is determined based on the comparison of the gap angles, the axial plays and the radial plays.

7. Method according to one of the preceding claims, wherein the evaluation device (10) evaluates the gap angles (ß) in the various rotational positions for deviations from one another and / or from at least one reference value, and an unnatural state of wear and / or a shortened remaining service life is determined when the deviations of the gap angles in the various rotational positions from one another and / or from the at least one reference value exceed a predetermined threshold value.

8. Method according to one of the preceding claims, wherein the evaluation device (10) adapts the at least one reference value and / or a / the permissible deviation of the angle of rotation and load-specific gap angles from one another to the stiffness of the installation environment, preferably by means of selectable surcharge and / or discount factors.

9. Method according to one of the preceding claims, wherein the at least one reference value is automatically initialized or mathematically determined by the evaluation device (10) when the monitoring of the rolling bearing is put into operation.

10. Device for monitoring a rolling bearing (1), with a sensor system (8) for determining a gap angle (ß) between the bearing rings (2, 3) of the rolling bearing (1) and an evaluation device (10) for evaluating the sensor signals of the sensor system (8), characterized in that a control device (9) is provided for specifying different rotational positions of the bearing rings relative to one another and different load conditions in each rotational position and the evaluation device (10) is designed to evaluate the rotational angle and load-specific gap angle determined by the sensor system (8) in the different rotational positions for the different load conditions according to the method according to one of claims 1 to 9 and to compare them with one another and / or with at least one reference value and to determine a wear condition and / or the remaining service life of the rolling bearing (1) on the basis of the comparison.

11. Rolling bearing, in particular in the form of a center-free large rolling bearing, with two bearings (2, 3) which can be rotated relative to one another and which are supported on one another by at least one row of rolling bearings (4, 5, 6), as well as a sensor system (8) for determining a gap angle (ß) between the bearings (2, 3), as well as an evaluation device (10) for evaluating the sensor signals of the sensor system (8), characterized in that a control device (9) is provided for specifying different rotational positions of the bearing rings relative to one another and different load states in each rotational position, and the evaluation device (10) is designed toto evaluate the angle of rotation and load-specific gap angles determined by the sensor system (8) in the various rotational positions for the various load conditions according to the method according to one of claims 1 to 9 and to compare them with each other and / or with at least one reference value and to determine a wear condition and / or the remaining service life of the rolling bearing (1) on the basis of the comparison.

12. Rolling bearing according to the preceding claim or its preamble, wherein the sensor system (8) has sensor elements (13, 14, 15, 16) arranged in different sectors for determining the gap angles (ß) in different sectors of the rolling bearing (1 ), which are arranged distributed around its axis of rotation (11 ), wherein an / the evaluation device (10) is designed to compare the gap angles (ß) occurring in the different sectors and to determine the state of wear and / or the remaining service life of the rolling bearing (1 ) based on the comparison of the gap angles (ß) in the different sectors.

13. Rolling bearing according to the preceding claim, wherein at least four sensor elements (13, 14, 15, 16) are provided in at least four sectors which are opposite one another in pairs and are designed to determine the gap angles (ß) in said at least four sectors.

14. Rolling bearing according to one of the preceding claims 11 to 13 or the preamble of claim 11, wherein the sensor system (8) comprises a plurality of inclination sensors ren (17, 18), wherein at least one inclination sensor (17, 18) is provided on each of the bearing rings (2, 3) and the evaluation device (10) is designed to determine the gap angle (ß) from the inclination signals determined on both bearings (2, 3).

15. Rolling bearing according to one of the preceding claims 11 to 14 or the preamble of claim 11, wherein the sensor system (8) comprises at least one triangulation sensor unit (19) which determines the gap angle (ß) at the bearing gap (7) between the two bearings (2, 3) by means of triangulation of a measuring signal.

16. Rolling bearing according to the preceding claim, wherein the triangulation sensor unit (19) has two signal emitters (s1, s2) and two signal receivers (e1, e2), wherein the signal emitters (s1, s2) are each attached to one of the bearing rings (1, 2) and project a signal onto a curved, preferably circular-arc or spherical-cap-shaped, contour of the other bearing ring, and the signal receivers (e1, e2) are designed to receive reflected signals and determine the angles (θ1, θ2) between the emitted signals of the signal emitters (s1, s2) and the received reflected signals.

17. Rolling bearing according to the preceding claim, wherein the signal emitters (s1, s2) are aligned substantially perpendicular to a center plane of the bearing gap (7).

18. Rolling bearing according to one of the preceding claims 11 to 17, wherein the sensor system (8) has at least one distance sensor for determining the distance between at least two contour sections of the bearing rings (2, 3) and the evaluation device (10) is designed to determine the gap angle (ß) from the distance signals determined on both bearing rings (2, 3).

19. Rolling bearing according to one of the preceding claims 11 to 18, wherein the sensor system (8) comprises at least two different sensor types from the group of inclination sensor, triangulation sensor unit and distance sensor.

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