METHOD AND DEVICE FOR DETECTING ELECTRICAL CURRENT PULSES OCCURRING IN A ROLLING BEARING AS A RESULT OF STATIC CHARGING OF ROTATING MACHINE/SYSTEM PARTS

Abstract

A method and to a device for detecting characteristic electrical current pulses flowing through a rolling bearing or sliding bearing as a result of static charging of rotating machine or system parts. The device is provided with a receiving unit with an antenna for receiving electromagnetic radio waves, which electromagnetic radio waves are emitted in the frequency range above 50 MHz as a result of the characteristic electrical current pulses, a signal processing unit for processing the received signal by signal processing in order to extract the current pulse events contained therein, and an analysis unit for analyzing the temporal progression of the current pulse events for state monitoring of the rolling bearing or sliding bearing.

Claims

1. A method for detecting characteristic electrical current pulses flowing through a rolling bearing or sliding bearing as a result of static charging of rotating machine or system parts, the method comprising the following steps: receiving electromagnetic radio waves emitted in a frequency range above 50 MHz as a result of the characteristic electrical current pulses; processing received signal by signal processing in order to extract current pulse events contained therein, including filtering; and analyzing a temporal progression of the current pulse events for condition monitoring of the rolling bearing or sliding bearing.

2. The method according to claim 1, wherein the processing of the received signal is implemented by an envelope formation.

3. The method according to claim 2, wherein the envelope formation includes high-pass filtering of the received signal followed by rectification and subsequent low-pass filtering.

4. The method according to claim 3, wherein the analysis includes integration of a processed signal obtained by the low-pass filtering in order to quantify the current pulse events that have occurred.

5. The method according to claim 3, wherein the analyzing includes counting a number of current pulse events of a processed signal per unit of time in order to quantify the current pulse events that have occurred.

6. A device for detecting characteristic electrical current pulses flowing through a rolling bearing or sliding bearing as a result of static charging of rotating machine or system parts, the device comprising: a receiving unit configured to receive electromagnetic radio waves emitted in a frequency range above 50 MHz as a result of the characteristic electrical current pulses; a signal processing unit configured to process a received signal by signal processing in order to extract current pulse events contained therein, including filtering; and an analysis unit configured to analyze a temporal progression of the current pulse events for condition monitoring of the rolling bearing or sliding bearing.

7. The device according to claim 6, wherein the receiving unit, the signal processing unit and the analysis unit are accommodated in a detection device which has a data transmission interface configured for connection to a system condition monitoring system or a system controller.

8. The device according to claim 7, wherein the detection device is a separate device with an integrated local alarm unit.

9. A wind power system comprising: a rotor as a rotating machine or system part, which is rotatably mounted on a support structure via at least one rolling bearing or sliding bearing provided as a rotor bearing, and the device according to claim 6 arranged in proximity to the rolling bearing or sliding bearing for detecting the characteristic current flows occurring as a result of static charging of the rotor in the at least one rolling bearing or sliding bearing between a bearing outer ring and a bearing inner ring.

10. A computer program product located in a tangible data storage medium comprising program code configured for executing the method according to claim 1, when the computer program product is run on a combined signal processing unit with an analysis unit.

11. A device for detecting characteristic electrical current pulses flowing through a rolling bearing or sliding bearing as a result of static charging of rotating machine or system parts, the device comprising: a receiver configured to receive electromagnetic radio waves emitted due to rotation of the rotating machine or system parts via the rolling or sliding bearing in a frequency range above 50 MHz as a result of the characteristic electrical current pulses; a signal processer configured to process a received signal from the receiver by signal processing in order to extract current pulse events contained therein, including filtering; and a signal analyzer configured to analyze a temporal progression of the current pulse events for condition monitoring of the rolling bearing or sliding bearing.

12. The device according to claim 11, wherein the signal processer and the signal analyzer are located in a detection device that includes a data transmission interface configured for connection to a system condition monitoring system or a system controller.

13. The device according to claim 12, wherein the detection device is a separate device with an integrated alarm.

14. A wind power system comprising: a rotor as a rotating machine or system part, which is rotatably mounted on a support structure via at least one rolling bearing or sliding bearing provided as a rotor bearing; and the device according to claim 6 arranged in proximity to the rolling bearing or sliding bearing for detecting the characteristic current flows occurring as a result of static charging of the rotor in the at least one rolling bearing or sliding bearing between a bearing outer ring and a bearing inner ring.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Further measures are shown in more detail below together with the description of a preferred exemplary embodiment according to the disclosure based on the figures. In the figures:

[0018] FIG. 1 shows a schematic block diagram representation of a device implemented in a wind power system for detecting electrical current pulses flowing through a rolling bearing as a result of static charging of the rotor;

[0019] FIG. 2 shows a schematic representation of an envelope formation for processing the received signal as a prerequisite for the signal analysis.

DETAILED DESCRIPTION

[0020] According to FIG. 1, a wind power system, shown here only schematically, has a rotor 1 which is rotatably mounted via a rolling bearing 2 designed as a rotor shaft bearing on a support structure 3 of a cabin on a tower of the wind power system (not shown in further detail).

[0021] During operation, the rotor blades of the rotor 1 experience static charging, which here flows through the rolling bearing 2, from the bearing inner ring 4 via the rolling elements 5 to the bearing outer ring 6 and into the grounded support structure 3. As a result, discharges in the rolling bearing 2 are emitted as electromagnetic radio waves, which are in a typical frequency range above 50 MHz.

[0022] A receiving unit 10 installed in the receiving region, i.e. close to the rolling bearing 2, is used for receiving 100 the electromagnetic radio waves via an antenna 11 attached thereto. A downstream signal processing unit 20 is used for processing 200 the received signal by signal processing in order to extract the current pulse events contained therein, which in this exemplary embodiment includes in particular an envelope formation. An analysis unit 30 is used for a subsequent analysis 300 of the temporal progression of the current pulse events for condition monitoring of the rolling bearing 2.

[0023] The receiving unit 10 is accommodated along with the signal processing unit 20 and the analysis unit 30 in a common detection device 40 which is connected to a system condition monitoring system (not shown in further detail) via a data transmission interface 50. Furthermore, an alarm unit 60 is also integrated in the detection device 50, which is used as a local optical display of a critical condition.

[0024] FIG. 2 illustrates the envelope formation that is preferably carried out in the course of the signal processing of the received electromagnetic radio waves. Accordingly, based on the received signal, high-pass filtering 400 first takes place in order to eliminate irrelevant signal components. This is followed by a rectification 500 which cuts away the sub-waves of the signal. Finally, low-pass filtering 600 ensures the formation of the area between the curve and the abscissa axis. This forms the prerequisite for a preferably subsequent integration in order to use the area per unit of time as a measurement variable for the current pulse events that have occurred.

[0025] The disclosure is not restricted to the preferred exemplary embodiment described above. Rather, modifications are also conceivable that are included in the scope of protection of the following claims. In particular, the solution according to the disclosure is not only applicable to wind power systems, but generally to non-wired current discharge scenarios. Furthermore, it should be noted that the signal processing for obtaining measurement variables is not limited solely to envelope formation of the received radio signal. Alternatively, sampling methods or other suitable analyzes can also be used for this purpose.

LIST OF REFERENCE SIGNS

[0026] 1 Rotor [0027] 2 Rolling bearing [0028] 3 Support structure [0029] 4 Bearing inner ring [0030] 5 Rolling element [0031] 6 Bearing outer ring [0032] 10 Receiving unit [0033] 11 Antenna [0034] 20 Signal processing unit [0035] 30 Analysis unit [0036] 40 Detection device [0037] 50 Data transmission interface [0038] 60 Alarm unit [0039] 100 Receiving of electromagnetic radio waves [0040] 200 Processing of the received signal [0041] 300 Analyzing of current pulse events [0042] 400 High-pass filtering [0043] 500 Rectification [0044] 600 Low-pass filtering [0045] I Current flow [0046] A Amplitude [0047] t Time