DE102008046357A1 - Sensor arrangement for determining a parameter for the wear of a rolling bearing and wind turbine - Google Patents

Abstract

The invention has for its object to provide a sensor arrangement for determining a characteristic for the wear of a rolling bearing and a wind turbine with this sensor arrangement, which allows a robust monitoring of wear. For this purpose, a sensor arrangement for determining a parameter for the wear of a rolling bearing is proposed, with two bearing rings 2, 3, wherein the bearing rings 2, 3 are arranged to rotate about rolling elements 4 about a common axis of rotation 5 against each other, with a sensor 11, which with one of Bearing rings 3 is connected, and with a detection area 14 which is arranged on the other bearing ring 2, wherein the sensor 11 detects the detection area 14, wherein the sensor 11 for detecting an axial offset of the bearing rings 2, 3 in the direction of the axis of rotation 5 than the Characteristic for the wear of the rolling bearing is formed, wherein the sensor arrangement is designed to determine a plurality of intermediate values of the axial offset.

Description

Field of the invention

The The invention relates to a sensor arrangement for determining a parameter for the wear of a rolling bearing with two bearing rings, wherein the bearing rings on rolling elements are arranged to rotate about a common axis of rotation against each other, with a sensor which is connected to one of the bearing rings and with a detection range, which is arranged on the other bearing ring is, wherein the sensor detects the detection area and wherein the Sensor for detecting an axial offset of the bearing rings in the direction the axis of rotation as the characteristic for the Wear of the rolling bearing is formed. The The invention also relates to a wind turbine with this sensor arrangement.

in the Permanent use of rolling bearings can cause wear and tear Runways and / or the rolling elements come. often the wear of the rolling bearing is a continuous one Process, which depends on a variety of factors, so that accurate predictions about the state of wear solely from operating data, such as number of revolutions, Operating time, etc. can not be determined with sufficient accuracy.

at Large-diameter bearings adds to that aggravating usually associated with special delivery times with certain delivery times are, allowing early detection of wear such slewing bearings desirable would. Economically, it seems neither to be meaningful, the slewing bearings too early to exchange several large bearings in stock to keep. On the other hand threatens the failure of such a large bearing the stoppage of the entire plant, into which the slewing bearing is installed.

From the utility model DE 20 316 544 U1 a monitoring device for monitoring large rolling bearings is known, which has at least two non-contact position measuring sensors, one of which is provided for determining radial movements and one for determining axial movements of the bearing rings relative to each other. By the joint evaluation of the signals of the distance measuring sensors and tilting movements are to be detected in the slewing bearings, which indicate a wear.

The patent DE 197 55 000 C1 on the other hand, concerns a much simpler and more robust embodiment of a wear measuring device for a slewing bearing and is probably the closest prior art. The wear measuring device has a probe which is arranged in an opening of one of the bearing rings and can come into contact with its end with a surface of the other bearing ring. The bearing ring, which is opposite to the probe, is formed with a groove into which projects the end of the probe. The side walls of the groove each have a distance from the probe, which corresponds to a predetermined wear in the associated direction. As soon as the wear limit defined by the groove width is reached, the probe contacts one of the side walls of the groove and a signal is output.

Of the Invention is based on the object, a sensor arrangement for determining a parameter for the wear of a Rolling and a wind turbine with this sensor arrangement to propose a robust monitoring of wear allowed.

These The object is achieved by a sensor arrangement having the features of the claim 1 and by a wind turbine with the features of the claim 15 solved. Preferred or advantageous embodiments The invention will become apparent from the dependent claims, the following description and the accompanying figures.

The The invention discloses a sensor assembly which is for use in determining a parameter for the wear of a Rolling and is suitable and / or trained. The sensor arrangement or the rolling bearing comprises two bearing rings, wherein the bearing rings on Rolling elements about a common axis of rotation against each other are arranged rotatable. The rolling bearing can be a single or multi-row design with any rolling elements represent. In particular, the rolling elements as Formed balls or rollers. Preferably, the bearing rings are at least partially coaxial and / or concentric and / or in radial Direction to the common axis of rotation overlapping each other arranged. In particular, the rolling bearing is considered a four-point rolling bearing educated.

The Sensor arrangement comprises a sensor, which with one of the bearing rings is firmly connected, so that the bearing ring determines its position. Furthermore, a detection area is provided on the other Bearing ring is arranged, wherein the sensor for detecting the detection area arranged and / or is formed.

The sensor is used to detect an axial offset of the bearing rings in the direction of the axis of rotation as the characteristic for the wear of the bearing. In a preferred embodiment, the rolling bearing is designed as a rotary joint, which receives significantly axial forces. The wear occurs in this design due to the loading direction often as a mutual displacement of the bearing rings in or against the direction of rotation axis up. This shift ultimately results from a reduction of the rolling elements and / or a depression of the raceways for the rolling elements in the bearing rings.

According to the invention proposed that the sensor arrangement for determining a plurality of intermediate values is formed of the axial offset. By the sensor can thus starting from a built-in or normal position of the bearing rings to each other preferably more than one intermediate value, in particular more than two Intermediate values are measured in a wear direction. At least two values are particularly preferred as intermediate values detected per wear direction, which differs from the built-in or normal position.

It is a consideration of the invention that the wear of the Wälzlagers so far and as in the beginning acknowledged Prior art described only a single limit is determined. Although the use of a single limit for wear determination better than the replacement of the rolling bearing only on the basis of the duration of operation, etc., but leaves a single limit value no sufficiently accurate determination of wear to. With the invention it is possible to reduce the actual wear in several intermediate values, in particular in a wear direction, that is, to determine in an axial direction of the axis of rotation. Accordingly, it is possible the maintenance and installation intervals individually set, as well as replacement times better too take into account, thus downtime of the respective plants with the rolling bearing can be minimized.

at a possible embodiment of the invention is the sensor arrangement for determining a plurality of discrete intermediate values designed for the axial offset. Such discreet Intermediate values can be given in mm, for example, so that a first intermediate value at 1 mm, a second intermediate value at 2 mm etc. is output. Of course you can the intermediate values also as dimensionless quantities be output from the sensor array.

at another possible embodiment of the invention is the sensor arrangement for the determination of continuous intermediate values educated. Such continuous intermediate values can be formed by each axial offset - in particular in terms of measurement accuracy - another intermediate value is assigned.

at In a practical realization of the invention, the sensor becomes tactile, optical, ultrasound-based, electrical and / or be formed magnetic detection of the detection area. Preferred are the types of measurement, which robust and especially at longer operating time are trouble-free.

at a particularly preferred embodiment of the invention is the sensor in the bearing ring, in particular in a bearing outer ring, integrated. The integration in the bearing ring ensures that that the sensor arrangement is not inadvertently adjusted during operation can still be damaged. Preferably, the bearing ring a radially extending receiving area, which for example is formed as a through hole. In this recording area the sensor is used, calibrated and fastened if necessary.

in principle the detection and / or measuring direction of the sensor can be arbitrary be formed as long as the detection area on the other Bearing ring is detected. In particular, angle dependencies However, it is preferable that the detection direction the sensor is aligned radially to the axis of rotation.

at a first possible embodiment of the invention the detection area is directly on or in the bearing ring introduced and / or molded. For example, the detection area is through a shape and / or surface change of the bearing ring reached.

at another possible embodiment of the invention is the detection area as a separate layer and / or a Separate component applied to the bearing ring. This embodiment has the advantage that the detection area separately with the desired Accuracy can be made and then as an accessory on the Bearing ring is placed on or.

Around To support the detection of the axial offset preferably provided that the detection area a coding in the axial direction. In this encoding are height information introduced to determine the axial offset can be used between the bearing rings.

at a first possible realization, the detection area Inkrementmarkierungen, so relative marks in the axial direction, on. In this realization, for example, provided that the Sensor counts the increments when the bearing rings are against each other move. In another possible realization Absolute markers arranged in the detection area, so that the sensor by capturing the absolute marks an absolute Measure the axial offset.

It is possible that the detection area is limited only to an angular range less than 360 °, preferably less than 180 °, in particular less than 90 °, as is usually assumed that a full rotation of the bearing, wherein at each revolution, the detection range is traversed once. However, it is preferred that the coding and / or the increment markings and / or the absolute markings and / or the detection area is formed completely circumferentially. This embodiment is particularly advantageous in compounds in which the rolling bearing performs no complete revolutions, but rather oscillating movements in a certain angular range during operation.

Especially preferred is an embodiment in which the detection area as a carrier, in particular as a film, with scale lines in the circumferential direction with a defined distance in the axial direction as Inkrementmarkierungen is formed.

at another possible embodiment is the detection area and / or encoding as a change in diameter in the Detection area formed using a ramp, a periodic or another pattern is formed in the axial direction. At a ramp For example, the varying by the wear Distance between the sensor and the detection area as continuous Intermediate values are read out. For a periodic pattern can discrete intermediate values are taken. Instead of a mechanical one Coding is in the same way also a magnetic, electrical and / or optical coding possible.

at a preferred concretization of the invention is the rolling bearing formed as a rotary joint. Particularly preferred is the Drehverbindung decisive for the transmission of formed axial forces, wherein in the axial direction the bearing rings to each other at least on one end face preferred arranged offset in height. Preferably, the Bearing rings in the axial direction extending passages, which for receiving fastening means, in particular screws, designed for attachment of the bearing ring to a construction are. The inner ring is preference, with a free through hole formed, in particular, the inner ring is mounted axle or shaft-free. The rolling elements can be arbitrary, preferably as Be realized balls and / or rollers. The slewing connection is a or formed in a multi-row. In particular, the rotary joint is preferred formed as a four-point camp.

Especially Advantageously, the invention is used in rolling bearings, as a slewing bearing with a pitch circle diameter larger than 1,000 mm are formed because here the axial offset due to wear become so great This can be done with the sensor array with sufficient resolution can be measured.

One Another object of the invention relates to a wind turbine with a rotary connection between tower and machine house and / or with a rotary joint as a leaf bearing for pivotally mounting a Rotor blade of the wind turbine, wherein the rotary joint a Sensor arrangement according to one of the preceding claims. The rotary connection allows the generator assembly in the respective orient the desired direction or the rotor blade to pivot.

Further Features, advantages and effects of the invention will become apparent the following description of preferred embodiments the invention. Showing:

1 a sectional view through the axis of rotation of a rotary joint for illustrating an embodiment of the invention;

2 a section of the material measure in the 1 ,

The 1 shows in a schematic sectional view of a rotary joint 1 as an embodiment of the invention, which has an inner bearing ring 2 , an outer bearing ring 3 which has a number of rolling elements 4 in the form of balls relative to each other about a common axis of rotation 5 are arranged rotatable.

The rotary joint 1 is designed as a large rolling bearing, wherein the pitch circle diameter, measured at the center of the rolling elements 4 greater than 1,000 mm is formed. The rotary joint 1 is installed, for example, in wind turbines, wherein the inner bearing ring 2 with its axial end face 6 a mechanical interface to a tower of the wind turbine and the outer bearing ring 3 with his front side 7 forms an interface to the structure with a generator, rotor, etc. Of course, the rotary joint 1 also be mounted the other way round or used on other applications.

To ensure interference-free operation, the inner bearing ring 2 and the outer bearing ring 3 formed offset in height by a distance D1 or D2. The rotary joint 1 is in the installation position significantly as Axialwälzlager for receiving axial forces, but also for receiving radial forces, relative to the axis of rotation 5 considered, for example, is designed as a four-point bearing. For fixing the inner bearing ring 2 or the outer bearing ring 3 are through holes 8th provided, which parallel to the axis of rotation 5 run and through the fasteners, such as bolts or screws can be performed.

In the operation of such rotary joints 1 it can cause wear and tear, especially on the rolling elements 4 or their careers 9 come, with the signs of wear by an axial offset of the inner bearing ring 2 and the outer bearing ring 3 result. In the illustration shown, it can thus come to a reduction of the sizes D1 and D2.

With the aim of performing an automated monitoring of the wear or a wear measurement, has the outer bearing ring 3 a recording room 10 on, which as radial to the axis of rotation 5 extending bore is formed and into which a sensor 11 on the inner bearing ring 2 facing the end of the recording room 10 is arranged. The sensor 11 is over a cable 12 with a data evaluation 13 connected.

The measuring direction of the sensor 11 is radial in the direction of the axis of rotation 5 aligned, the sensor 11 a detection area 14 on the inner bearing ring 2 metrologically recorded.

The coverage area 14 is for example as a material measure 15 formed, as these sections in radial plan view in the 2 is shown. The measuring standard 15 is formed as a film, in particular a plastic film, which circumferentially around the inner bearing ring 2 or the axis of rotation 5 arranged, for example glued or shrunk, is. The measuring standard 15 has a plurality of also extending in the circumferential direction of scale 16 on, which are arranged equidistant in the axial direction to each other. The measure personification lines 16 are closed in the direction of rotation.

For a wear-related axial offset of the outer bearing ring 3 relative to the inner bearing ring 2 in the direction of the axis of rotation 5 the sensor moves 11 one or more of the scale lines 16 which of the sensor 11 for example, optically recorded and from the data evaluation 13 be evaluated as incremental markers. The data evaluation 13 counts the number of the sensor 11 crossed over scale lines 16 and can - possibly after a corresponding calibration - a parameter for the axial offset of the two bearing rings 2 . 3 and thus a parameter for the current or actual wear of the rotary joint 1 output. The measure personification lines 16 For example, are arranged at a distance of less than 1 mm, preferably less than 0.5 mm and in particular less than 0.2 mm.

The advantage of the sensor arrangement in the 1 is to be seen in particular in that from the characteristics of the data analysis 13 the current wear of the raceways 9 the rotary joint 1 can be determined so that maintenance and installation intervals can be determined depending on the wear and individually. Optionally, also long replacement times of the rotary joint 1 be better taken into account and thus the wear-related downtime of the respective systems are shortened with the rotary joint.

1

rotary joint

2

internal bearing ring

3

outer bearing ring

4

rolling elements

5

axis of rotation

6

axial front

7

front

8th

Through openings

9

raceways

10

accommodation space

11

sensor

12

electric wire

13

data analysis

14

detection range

15

Measuring standard

16

Maßverkörperungslinien

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 20316544 U1 [0004]
• - DE 19755000 C1 [0005]

Claims (15)

Sensor arrangement for determining a parameter for the wear of a rolling bearing, with two bearing rings ( 2 . 3 ), whereby the bearing rings ( 2 . 3 ) via rolling elements ( 4 ) about a common axis of rotation ( 5 ) are rotatable against each other, with a sensor ( 11 ), which with one of the bearing rings ( 3 ) and a detection area ( 14 ) on the other bearing ring ( 2 ) is arranged, wherein the sensor ( 11 ) the coverage area ( 14 ), wherein the sensor ( 11 ) for detecting an axial offset of the bearing rings ( 2 . 3 ) in the direction of the axis of rotation ( 5 ) is formed as the parameter for the wear of the rolling bearing, characterized in that the sensor arrangement is designed to determine a plurality of intermediate values of the axial offset. Sensor arrangement according to claim 1, characterized that the sensor arrangement for determining a plurality of discrete and / or formed continuous intermediate values for the axial offset is. Sensor arrangement according to one of the preceding claims 1 or 2, characterized in that the sensor ( 11 ) is designed for tactile, optical, electrical and / or magnetic detection of the detection area. Sensor arrangement according to one of the preceding claims, characterized in that the sensor ( 11 ) in the bearing ring ( 2 ) is integrated. Sensor arrangement according to one of the preceding claims, characterized in that the detection direction of the sensor radially to the axis of rotation ( 5 ) is aligned. Sensor arrangement according to one of the preceding claims, characterized in that the detection area directly on introduced and / or molded in the bearing ring. Sensor arrangement according to one of the preceding claims, characterized in that the detection area ( 14 ) as a separate layer and / or a separate component ( 15 ) is applied to the bearing ring. Sensor arrangement according to one of the preceding claims, characterized in that the detection area ( 14 ) has a coding in the axial direction. Sensor arrangement according to one of the preceding claims, characterized in that the detection area increment markings ( 16 ) and / or having absolute marks in the axial direction. Sensor arrangement according to claim 9 or 10, characterized in that the coding and / or the increment marking ( 16 ) is formed completely circumferential. Sensor arrangement according to one of the preceding claims, characterized in that the coding as a foil ( 15 ) is formed with dimensional standards. Sensor arrangement according to one of the preceding claims 9 to 10, characterized in that the coding as a change in diameter of the bearing ring ( 2 ) within the scope ( 14 ) is trained. Sensor arrangement according to one of the preceding claims, characterized in that the rolling bearing as a rotary joint ( 1 ) is trained. Sensor arrangement according to one of the preceding claims, characterized in that the rolling bearing as a slewing bearing with a pitch circle diameter greater than 1000 mm is formed. Wind energy plant with a rotary joint ( 1 ) between the tower and the structure and / or as a leaf bearing, characterized in that the rotary joint ( 1 ) has a sensor arrangement according to one of the preceding claims.