Methods and systems for monitoring geared motors

Abstract

The present invention relates to a method and a system for monitoring a geared motor having a gearbox at least partially filled with oil, wherein the oil level, particularly the oil filling height, is detected, and the vibration at at least one part of the gearbox is detected, wherein a first parameter is formed by calculating the oil level and the vibration, and the value of the first parameter is monitored to see if it exceeds an allowable deviation from a target value or exceeds a threshold.

Description

Technical Field

[0001] This invention relates to a method and a system for monitoring a geared motor. Background Technology

[0002] As is well known, it is necessary to detect the rotational speed of the motor's rotor shaft. Summary of the Invention

[0003] Therefore, the purpose of this invention is to implement the drive flexibly and adaptably while ensuring a high level of safety.

[0004] According to the present invention, the objective is achieved by a system according to claim 1 and a method according to claim 11.

[0005] An important feature of the system according to the invention is that the system includes a reducer driven by a motor and a modularly formed evaluation unit, the motor being powered by an inverter, wherein the evaluation unit has an evaluation module, a central module, and a power supply module.

[0006] The advantage here is that the modular construction of the evaluation unit allows for the addition of other evaluation units, and thus, additional sensors, enabling the central module to perform improved evaluations. The number of evaluation units, and consequently, the number of sensors, can be adapted to the corresponding drive task. This allows for flexible adaptation in terms of cost and expenditure. For example, sensors can also be included to detect the torque and / or speed output on the output shaft and transmit this information to the central module. The central module connects not only to indicator components for providing warning information but also to the controller of the inverter that powers the motor. This also improves safety, as sensors can be easily added, and the central module can therefore perform improved monitoring of the reducer, particularly improved condition monitoring.

[0007] In a favorable design, the evaluation module, central module, and power supply module are arranged side-by-side. The advantage here is that these modules can be arranged in a row, thus providing a clear overview of the evaluation unit's structure. Furthermore, additional modules can be easily added at the ends without requiring any hardware modifications to the remaining evaluation units.

[0008] In an advantageous design, the evaluation module and the central module are powered in parallel from the power supply module. The advantage here is that the evaluation module and the central module can be powered by DC voltage from the power supply module fed by the AC voltage supply network. Here, the power supply module has a rectifier, particularly a smoothing capacitor. Preferably, the DC voltage supply forms a loop through the evaluation modules, which are connected in series in contact with each other via plug-in electrical connections.

[0009] In a favorable design, sensors correspondingly arranged on the reducer are electrically connected to an evaluation module paired with them. The advantage here is that the sensor signals can be processed independently. In particular, low-pass filtering, amplification, and / or compensation voltages can be used or added to the sensor signals. Furthermore, analog signals can be converted into digital data streams, which are then fed to the central module.

[0010] In a favorable design, each evaluation module has its own housing. The advantage here is that signal processing can be performed within each module without interference from signals from other modules.

[0011] In a favorable design, each evaluation module is connected to the central module via a wireless or wired data transmission channel. The advantage here is that data detected and processed by the sensors can be transmitted to the central module. Therefore, signals from the various sensors can be processed against each other, and the results can be monitored for deviations from the target value or target value range that are not allowed to be too high, particularly for status monitoring.

[0012] In an advantageous design, the central module has components for processing sensor signals, and the processing results are sent to components for monitoring. These monitoring components are connected to components for indicating warning information and / or to components for shutting off the motor. The advantage here is that improved monitoring can be achieved. This is because monitoring can be distorted by fluctuations, particularly around threshold values, which can lead to errors. According to the invention, multiple parameters are processed together, thus forming a more sensitive combined parameter. Preferably, the monitoring components include components for storing preset thresholds and components for comparing the processing results with the preset thresholds.

[0013] In an advantageous design, the first sensor is suitable for detecting the oil level, particularly the fill height of the oil currently present in the reducer. The advantage here is that the fill height can be monitored and calculated with other parameters. Therefore, a combination of parameters can be formed, and signals from other sensors that also produce changing signals as the oil level drops can be provided to this combination. For example, the averaged solid-element acoustic amplitude over a frequency band can be increased.

[0014] In a favorable design, the second sensor is used to detect vibrations in the reducer. The advantage here is that the solid-borne acoustic amplitude of the reducer, particularly near the bearings, can be determined and can be processed with sensor signals from other sensors.

[0015] In an advantageous design, the third sensor is suitable for detecting the temperature of the reducer; in particular, the third sensor is an infrared sensor and / or the third sensor is arranged inside the reducer housing component. The advantage here is that the signal from the third sensor can be processed with the signals from the other two sensors, thus allowing the determination of different physical parameters that change its signal as the oil level decreases.

[0016] In the method for monitoring a geared motor, particularly the method implemented by the aforementioned system, an important feature is that the geared motor has a reducer at least partially filled with oil, wherein the value of the oil level, particularly the value of the oil filling height, is detected, and the value of vibration at at least one part of the reducer is detected, wherein a first parameter is formed by calculating the value of the oil level and the value of the vibration, and the deviation of the value of the first parameter from a target value is monitored to see if it exceeds an allowable level, or whether the first parameter exceeds a threshold.

[0017] The advantage here is that if the oil level drops, the calculated parameters change its signal.

[0018] In an advantageous design, upon exceeding the time limit, a warning message is indicated and / or forwarded, and / or the inverter-powered motor driving the gearbox is shut down or the inverter-powered motor driving the gearbox is activated to a safe state. The advantage here is that enhanced safety can be achieved.

[0019] In a favorable design, the calculation involves division, where the first parameter is formed as the quotient of the vibration value and the oil level value. The advantage here is that simple mathematical operations are sufficient to improve sensitivity.

[0020] In a favorable design, the calculation involves division, where the first parameter is formed as the quotient of the product of the vibration value and the reducer temperature value, and the oil level value. The advantage here is that high sensitivity can be achieved through simple mathematical operations, and therefore effective monitoring can be implemented.

[0021] In a favorable design, the vibration value is the average of the time-varying curves of the vibration value after Fourier transform, particularly the average value within a frequency band. The advantage here is that if the bearing lubrication deteriorates, the frequency of the band generated by the bearing will significantly affect this value.

[0022] Further advantages are provided by the dependent claims. The invention is not limited to the combination of features of the claims. For those skilled in the art, particularly for purposes proposed and / or proposed by comparison with the prior art, other reasonable combinations of features of the claims and / or individual claims and / or description features and / or drawings are possible. Attached Figure Description

[0023] The invention will now be described in detail with reference to the accompanying drawings:

[0024] exist Figure 1 The diagram illustrates a monitoring system according to the present invention. Detailed Implementation

[0025] The reducer has a housing component 1 in which bearings are received for supporting shafts, and gear components are connected to these shafts in a manner that prevents relative rotation.

[0026] Input shaft 2, especially drive shaft, is connected to the rotor shaft of the motor in a manner that prevents relative rotation or via a clutch device.

[0027] Output shaft 6 can be connected to the load to be driven.

[0028] Sensors are arranged on or in the housing component 1, particularly an oil level sensor 3 for detecting the oil level surrounded by the housing component 1, a temperature sensor 4 for detecting the temperature inside the housing component, and a vibration sensor 5 for detecting mechanical vibration, particularly acoustic vibration, of the housing component 1, particularly a solid-state acoustic sensor.

[0029] The sensor signal is transmitted to Figure 1 The evaluation unit 7 is shown in the figure.

[0030] Evaluation unit 7 comprises an evaluation module, a central module 8, and a power supply module 9, arranged side by side. Here, the evaluation module and the central module are powered in parallel by the power supply module.

[0031] The sensor signal of the oil level sensor 3 is sent to the first evaluation module 13 in the evaluation module, the sensor signal of the temperature sensor 4 is sent to the second evaluation module 14 in the evaluation module, and the sensor signal of the vibration sensor 5 is sent to the third evaluation module 15 in the evaluation module.

[0032] Central module 8 is connected to the evaluation module via a data transmission channel.

[0033] The central module evaluates the measured values ​​detected and determined by sensors and the evaluation module, where status monitoring is implemented.

[0034] Here, this monitoring of measured values ​​in the central module enables the issuance of warning signals and / or shutdown signals when deviations from the specified range exceed permissible levels.

[0035] Here, the shutdown signal—particularly through the inverter supplying power to the motor—causes the motor to shut down or activate in a safe state. This safe state does not necessarily have to be a stationary state of the rotor shaft, but can also be a regular, preferably uniform, rotation of the motor's rotor shaft.

[0036] That is, the central module performs calculations on the measurements determined by the evaluation module and monitors them accordingly.

[0037] For example, a first parameter can be formed, which includes the quotient of the product of the oil level and the oil level value of the detected oil level, the product being the detected temperature and the value determined by the vibration value detected by means of a vibration sensor.

[0038] As a value determined by vibration detected by a vibration sensor, the amplitude of the filtered frequency or the average amplitude of the frequency band is used, exemplarily. Preferably, the signal from the vibration sensor 5 is fed to an FFT, and the average amplitude value and / or the integral of the amplitude is formed from the Fourier spectrum for the frequency band thus determined according to the frequency.

[0039] If, for example, the oil level drops, thus worsening the lubrication of the bearings and / or the meshing gear components, the value determined by the vibration value detected by a vibration sensor increases, and the friction of the meshing gear components also increases.

[0040] The first parameter reacts extremely strongly through the resulting operations, particularly the formation of quotients and products. This is because a slight drop in oil level can lead to increased small vibrations and a rise in temperature. Significant changes in the value of the first parameter are obtained through multiplication and division. In this way, high sensitivity to changes is achieved.

[0041] The improved scheme can also use operations with similar mathematical properties.

[0042] Additionally, the motor current can be detected using a sensor for detecting the motor current, and the sensor signal can be transmitted to another evaluation module. From there, the value thus determined is sent to a central module, which calculates these values, thus determined by the detected motor current, with respect to values ​​from other sensors, thereby monitoring the calculation results for deviations from permissible values ​​that are not allowed to be too large.

[0043] In another embodiment of the invention, a Fourier transform curve of the value detected by the vibration sensor 5 is formed, specifically the RMS value, i.e., the root mean square value, in a certain frequency band. This forms the quotient of the RMS value and the value determined by the signal from the oil level sensor 3, and monitors it for deviations from a threshold that are not allowed to be too high. Therefore, parameters that are highly sensitive to changes caused by deterioration in lubrication can be obtained for monitoring.

[0044] List of reference numerals in the attached diagram:

[0045] 1. Housing components

[0046] 2. Input shafts, especially drive shafts

[0047] 3. Oil level sensor

[0048] 4 Temperature sensor

[0049] 5. Vibration sensors, especially solid-state acoustic sensors

[0050] 6 Output shaft

[0051] 7. Evaluation Unit

[0052] 8. Central Module

[0053] 9 Power Supply Module

[0054] 13 First Assessment Module

[0055] 14 Second Assessment Module

[0056] 15. Third Assessment Module.

Claims

1. A system comprising a reducer driven by a motor and a modularly formed evaluation unit, wherein the motor is powered by an inverter, wherein, The evaluation unit consists of an evaluation module, a central module, and a power supply module. The system includes a first sensor, a second sensor, and a third sensor. The first sensor is used to detect the oil level in the reducer, the second sensor is used to detect the vibration of the reducer, and the third sensor is used to detect the temperature of the reducer. The system is constructed as follows: The first parameter is formed through calculation. Monitor whether the value of the first parameter deviates from the allowable range from the target value or exceeds the threshold. The operation includes division, wherein, The first parameter is formed as the quotient of the vibration value and the oil level value, or The first parameter is formed as the quotient of the product of the vibration value and the reducer temperature value and the oil level value.

2. The system according to claim 1, characterized in that, The evaluation module, central module, and power supply module are arranged side by side.

3. The system according to claim 1 or 2, characterized in that, The evaluation module and the central module are powered in parallel by the power supply module.

4. The system according to claim 1 or 2, characterized in that, Each sensor mounted on the reducer is electrically connected to an evaluation module assigned to it on a one-to-one basis.

5. The system according to claim 1 or 2, characterized in that, Each evaluation module has its own shell.

6. The system according to claim 1 or 2, characterized in that, Each evaluation module is connected to the central module via a wireless or wired data transmission channel.

7. The system according to claim 1 or 2, characterized in that, The central module has a component for processing sensor signals, and the result of the processing is sent to a component for monitoring. This monitoring component is connected to a component for indicating warning information and / or to a component for shutting off the motor.

8. The system according to claim 1 or 2, characterized in that, The third sensor is an infrared sensor, and / or the third sensor is arranged inside the housing component of the reducer.

9. A method for monitoring a geared motor, said method being implemented by a system according to any one of claims 1-8. The geared motor has a reducer that is at least partially filled with oil. Detect the oil level and the vibration level at at least one location on the reducer. Its features are, The first parameter is formed through calculation. Monitor whether the value of the first parameter exceeds the allowable deviation from the target value or exceeds the threshold.

10. The method according to claim 9, characterized in that, If the time limit is exceeded, an alert message will be displayed and / or forwarded, and / or the inverter-powered motor driving the gearbox will be shut down immediately, or the safety status of the inverter-powered motor driving the gearbox will be activated.

11. The method according to claim 9 or 10, characterized in that, The vibration value is the average value of the time-varying curve of the vibration value after Fourier transform in one frequency band.

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