Device and method for detecting electro-corrosion fault of speed reducer bearing in all-in-one electric drive

Abstract

The invention discloses an electro-corrosion fault detection device and method for a reducer bearing in all-in-one electric drive, and the method comprises the steps: determining whether the bearing inner ring of an input shaft, the bearing inner ring of an intermediate shaft and the bearing inner ring of an output shaft of a reducer are subjected to electro-corrosion or not through measuring voltage difference signals between the bearing inner ring of the input shaft, the bearing inner ring of the intermediate shaft and the bearing inner ring of the output shaft and grounding points, and selecting n grounding points for detection. The speed reducer bearing electrocorrosion fault detection device can comprehensively and perfectly detect the electrocorrosion fault of a speed reducer bearing, avoids the problem of detection errors possibly caused by single grounding point detection, can ensure the accuracy of a detection result, and realizes high-accuracy electrocorrosion fault detection, thereby improving the reliability and maintenance efficiency of an all-in-one electric drive.

Description

Technical Field

[0001] The present invention belongs to the field of equipment fault detection of electric vehicles, and specifically relates to a device and method for detecting electrical corrosion faults of reducer bearings in an all-in-one electric drive. Background Art

[0002] The reducer in the all-in-one electric drive system (abbreviated as all-in-one electric drive) is a key component connecting the motor and the load, and plays a vital role. The bearings in the reducer (such as the input shaft bearing, intermediate shaft bearing, and output shaft bearing) bear important support and motion transmission functions, and their health directly affects the performance and life of the entire system. However, due to the use of high-frequency PWM (i.e. pulse width modulation) power supplies and inverters in the motor, electrical corrosion of the bearings has become one of the main problems affecting their life.

[0003] Electrical corrosion is caused by electrical discharge caused by the tiny current inside the motor passing through the bearing. This discharge will cause pitting corrosion on the raceway and rolling elements of the bearing, accelerating the aging and failure of the bearing. In addition, since the early symptoms of electrical corrosion are not obvious, once obvious damage is found, the bearing is often close to or in a state of failure, which significantly increases the maintenance cost and may cause unexpected downtime.

[0004] In the motor and reducer system, the phenomenon of electrical corrosion of bearings has long been a hot topic of research. The bearings of drive motors are often the focus of researchers due to their inherent characteristics of high-speed operation and current leakage. In existing patent literature, a large number of technical solutions have been proposed to inhibit or reduce the impact of electrical corrosion on motor bearings, including improving bearing materials, adding insulation layers, adjusting motor design, etc.

[0005] However, the issue of electrical corrosion in reducer bearings, especially tapered bearings on intermediate and output shafts, has not received the same level of attention. In fact, the electrical corrosion of reducer input shaft bearings, intermediate shaft bearings, and output shaft bearings (also known as differential bearings) is also a high risk because they are often plagued by electrical corrosion, especially in high-voltage and high-frequency electrical environments. Electrical corrosion not only damages the physical structure of the bearings and shortens their service life, but can also cause a decrease in reducer efficiency and even cause system failure. Summary of the invention

[0006] The object of the present invention is to provide a device and method for detecting electrical corrosion faults of reducer bearings in an all-in-one electric drive, so as to achieve high-accuracy electrical corrosion fault detection, thereby improving the reliability and maintenance efficiency of the all-in-one electric drive.

[0007] In the first aspect, the present invention provides a device for detecting the electrical corrosion fault of a reducer bearing in an all-in-one electric drive, wherein the all-in-one electric drive is integrated with at least an electric control, a motor and a reducer. The detection device comprises: a powertrain bench for driving the all-in-one electric drive to operate under a detection condition, a first brush probe for measuring the voltage difference signal from the inner ring of the input shaft bearing to the grounding point, a second brush probe for measuring the voltage difference signal from the inner ring of the intermediate shaft bearing to the grounding point, a third brush probe for measuring the voltage difference signal from the inner ring of the output shaft bearing to the grounding point, a signal acquisition and display module whose grounding end can be electrically connected to the grounding point, and a fault identification module for identifying whether there is an electrical corrosion fault of the bearing; the first brush probe, the second brush probe and the third brush probe are electrically connected to the three signal input ends of the signal acquisition and display module through wires respectively, and the signal output end of the signal acquisition and display module is electrically connected to the fault identification module; wherein, there are n grounding points, and the n grounding points are arranged at intervals on the housing of the all-in-one electric drive, and n≥2.

[0008] The signal acquisition and display module obtains and displays the voltage difference signal from the inner ring of the input shaft bearing to the grounding point from the first brush probe, obtains and displays the voltage difference signal from the inner ring of the intermediate shaft bearing to the grounding point from the second brush probe, and obtains and displays the voltage difference signal from the inner ring of the output shaft bearing to the grounding point from the third brush probe. The fault identification module determines whether the input shaft bearing, the intermediate shaft bearing, and the output shaft bearing are electro-corroded, and whether there is a bearing electro-corrosion fault based on the voltage difference signal from the inner ring of the input shaft bearing to the grounding point, the voltage difference signal from the inner ring of the intermediate shaft bearing to the grounding point, and the voltage difference signal from the inner ring of the output shaft bearing to the grounding point transmitted by the signal acquisition and display module.

[0009] Preferably, n=3, and the three grounding points are respectively a first grounding point, a second grounding point and a third grounding point. The first grounding point is arranged on the reducer housing between the intermediate shaft and the output shaft, the second grounding point is arranged on the reducer housing close to the motor side, and the third grounding point is arranged on the electronic control housing.

[0010] Preferably, the signal acquisition and display module is an oscilloscope. Using an oscilloscope for display can make it more convenient for testers to observe the voltage difference waveform.

[0011] In a second aspect, the present invention provides a method for detecting electrical corrosion faults of reducer bearings in an all-in-one electric drive, which uses the above-mentioned detection device, and the detection method comprises: Install the all-in-one electric drive on the powertrain stand.

[0012] The first brush probe is in contact with the inner ring of the input shaft bearing, the second brush probe is in contact with the inner ring of the intermediate shaft bearing, and the third brush probe is in contact with the end face of the large disc tooth of the output shaft.

[0013] The grounding terminal of the signal acquisition and display module is electrically connected to the i-th grounding point, and the powertrain test bench drive all-in-one electric drive operates under the detection condition. The fault identification module identifies whether the input shaft bearing, the intermediate shaft bearing and the output shaft bearing corresponding to the i-th grounding point (that is, when the grounding terminal of the acquisition and display module is electrically connected to the i-th grounding point) are electrically corroded according to the voltage difference signal from the inner ring of the input shaft bearing to the grounding point, the voltage difference signal from the inner ring of the intermediate shaft bearing to the grounding point and the voltage difference signal from the inner ring of the output shaft bearing to the grounding point transmitted by the signal acquisition and display module; wherein i is taken to be all integers from 1 to n in sequence.

[0014] If the input shaft bearings corresponding to the n grounding points do not suffer from electrical corrosion, the fault identification module determines that the input shaft bearings do not suffer from electrical corrosion faults, otherwise it determines that the input shaft bearings suffer from electrical corrosion faults. The grounding terminal of the acquisition and display module is electrically connected to one grounding point each time, and when it is executed n times, the first grounding point will be electrically connected to the nth grounding point respectively, and the fault identification module will also identify n times.

[0015] That is, as long as electrical corrosion occurs in the input shaft bearing corresponding to one grounding point, it is determined that the input shaft bearing has an electrical corrosion fault.

[0016] If the intermediate shaft bearings corresponding to the n grounding points do not suffer from electrical corrosion, the fault identification module determines that the intermediate shaft bearings do not suffer from electrical corrosion faults, otherwise it is determined that the intermediate shaft bearings suffer from electrical corrosion faults. That is, as long as the intermediate shaft bearings corresponding to one grounding point suffer from electrical corrosion, it is determined that the intermediate shaft bearings suffer from electrical corrosion faults.

[0017] If the output shaft bearings corresponding to the n grounding points do not suffer from electrical corrosion, the fault identification module determines that the output shaft bearings do not suffer from electrical corrosion faults, otherwise it is determined that the output shaft bearings suffer from electrical corrosion faults. That is, as long as the output shaft bearings corresponding to one grounding point suffer from electrical corrosion, it is determined that the output shaft bearings suffer from electrical corrosion faults.

[0018] Preferably, a first through hole is provided on the reducer housing corresponding to the position of the inner ring of the input shaft bearing, and the first brush probe passes through the first through hole to contact the inner ring of the input shaft bearing, and is insulated from the reducer housing to ensure the accuracy of the derived signal. A second through hole is provided on the reducer housing corresponding to the position of the inner ring of the intermediate shaft bearing, and the second brush probe passes through the second through hole to contact the inner ring of the intermediate shaft bearing, and is insulated from the reducer housing to ensure the accuracy of the derived signal. A third through hole is provided on the reducer housing corresponding to the position of the large disc tooth end face of the output shaft, and the third brush probe passes through the third through hole to contact the large disc tooth end face of the output shaft, and is insulated from the reducer housing to ensure the accuracy of the derived signal. Since the output shaft needs to be connected to a load, if the third brush probe is placed at the position of the inner ring of its bearing, it will be disturbed; therefore, the third brush probe is contacted with the large disc tooth end face of the output shaft, and the large disc tooth end face of the output shaft is close to the inner ring of the output shaft bearing, and the voltage difference is almost zero. Measuring the voltage difference from the large disc tooth end face of the output shaft to the grounding point is equivalent to measuring the voltage difference from the inner ring of the output shaft bearing to the grounding point.

[0019] Preferably, when n=3, and the three grounding points are respectively a first grounding point, a second grounding point and a third grounding point, there are two determination and processing methods.

[0020] The first judgment processing method is: The ground terminal of the signal acquisition and display module is electrically connected to the first ground point (ie, the first ground point).

[0021] If the input shaft bearings, intermediate shaft bearings and output shaft bearings corresponding to the first grounding point are all electro-corroded, the fault identification module determines that the input shaft bearings, intermediate shaft bearings and output shaft bearings are all electro-corroded, and completes the reducer bearing fault detection (no need to switch to the second grounding point for detection); otherwise, the grounding terminal of the signal acquisition and display module is electrically connected to the second grounding point (i.e., the second grounding point).

[0022] If the input shaft bearings, intermediate shaft bearings and output shaft bearings corresponding to the second grounding point are all electro-corroded, the fault identification module determines that the input shaft bearings, intermediate shaft bearings and output shaft bearings are all electro-corroded, and completes the reducer bearing fault detection (no need to switch to the third grounding point for detection); otherwise, the grounding terminal of the signal acquisition and display module is electrically connected to the third grounding point (i.e., the third grounding point).

[0023] If the input shaft bearing corresponding to the third grounding point, the input shaft bearing corresponding to the second grounding point, and the input shaft bearing corresponding to the first grounding point do not experience electrical corrosion, the fault identification module determines that there is no electrical corrosion fault in the input shaft bearing, otherwise it is determined that there is an electrical corrosion fault in the input shaft bearing.

[0024] If the intermediate shaft bearing corresponding to the third grounding point, the intermediate shaft bearing corresponding to the second grounding point, and the intermediate shaft bearing corresponding to the first grounding point do not experience electrical corrosion, the fault identification module determines that there is no electrical corrosion fault in the intermediate shaft bearing, otherwise it is determined that there is an electrical corrosion fault in the intermediate shaft bearing.

[0025] If the output shaft bearing corresponding to the third grounding point, the output shaft bearing corresponding to the second grounding point, and the output shaft bearing corresponding to the first grounding point do not experience electrical corrosion, the fault identification module determines that there is no electrical corrosion fault in the output shaft bearing, otherwise it is determined that there is an electrical corrosion fault in the output shaft bearing.

[0026] The second judgment processing method is: The ground terminal of the signal acquisition and display module is electrically connected to the first ground point (ie, the first ground point).

[0027] If the input shaft bearing corresponding to the first grounding point undergoes electrical corrosion, the fault identification module determines that the input shaft bearing has an electrical corrosion fault and completes the input shaft bearing fault detection; if the intermediate shaft bearing corresponding to the first grounding point undergoes electrical corrosion, the fault identification module determines that the intermediate shaft bearing has an electrical corrosion fault and completes the intermediate shaft bearing fault detection; if the output shaft bearing corresponding to the first grounding point undergoes electrical corrosion, the fault identification module determines that the output shaft bearing has an electrical corrosion fault and completes the output shaft bearing fault detection.

[0028] If at least one of the input shaft bearing, intermediate shaft bearing and output shaft bearing corresponding to the first grounding point has not been electrically corroded, the grounding terminal of the signal acquisition and display module is electrically connected to the second grounding point (i.e., the second grounding point). Otherwise, the reducer bearing fault detection is completed without switching to the second grounding point for detection.

[0029] If the input shaft bearing corresponding to the second grounding point undergoes electrical corrosion, the fault identification module determines that the input shaft bearing has an electrical corrosion fault and completes the input shaft bearing fault detection; if the intermediate shaft bearing corresponding to the second grounding point undergoes electrical corrosion, the fault identification module determines that the intermediate shaft bearing has an electrical corrosion fault and completes the intermediate shaft bearing fault detection; if the output shaft bearing corresponding to the second grounding point undergoes electrical corrosion, the fault identification module determines that the output shaft bearing has an electrical corrosion fault and completes the output shaft bearing fault detection.

[0030] If at least one of the input shaft bearing, intermediate shaft bearing and output shaft bearing corresponding to the second grounding point has not been electrically corroded, the grounding terminal of the signal acquisition and display module is electrically connected to the third grounding point (i.e., the third grounding point). Otherwise, the reducer bearing fault detection is completed without switching to the third grounding point for detection.

[0031] If the input shaft bearing corresponding to the third grounding point is electro-corroded, the fault identification module determines that the input shaft bearing has an electro-corrosion fault and completes the input shaft bearing fault detection. If the input shaft bearing corresponding to the third grounding point is not electro-corroded, the fault identification module determines that the input shaft bearing does not have an electro-corrosion fault and completes the input shaft bearing fault detection.

[0032] If the intermediate shaft bearing corresponding to the third grounding point is electro-corroded, the fault identification module determines that the intermediate shaft bearing has an electro-corrosion fault and completes the intermediate shaft bearing fault detection. If the intermediate shaft bearing corresponding to the third grounding point is not electro-corroded, the fault identification module determines that the intermediate shaft bearing does not have an electro-corrosion fault and completes the intermediate shaft bearing fault detection.

[0033] If the output shaft bearing corresponding to the third grounding point is electro-corroded, the fault identification module determines that the output shaft bearing has an electro-corrosion fault and completes the output shaft bearing fault detection. If the output shaft bearing corresponding to the third grounding point is not electro-corroded, the fault identification module determines that the output shaft bearing does not have an electro-corrosion fault and completes the output shaft bearing fault detection.

[0034] Preferably, if the voltage difference U1 from the inner ring of the input shaft bearing to the grounding point satisfies both conditions 1a and 1b, it indicates that the input shaft bearing has undergone electrical corrosion; wherein condition 1a is: the peak value of U1 exceeds the preset voltage threshold range; condition 1b is: the waveform of U1 has at least m high-frequency spike pulses within the preset time t (high-frequency spike pulse refers to a signal with an extremely short period, extremely high frequency, and sharp waveform); m represents the preset number threshold. If the voltage difference U2 from the inner ring of the intermediate shaft bearing to the grounding point satisfies both conditions 2a and 2b, it indicates that the intermediate shaft bearing has undergone electrical corrosion; wherein condition 2a is: the peak value of U2 exceeds the preset voltage threshold range; condition 2b is: the waveform of U2 has at least m high-frequency spike pulses within the preset time t. If the voltage difference U3 from the inner ring of the output shaft bearing to the grounding point satisfies both conditions 3a and 3b, it indicates that the output shaft bearing has undergone electrical corrosion; wherein condition 3a is: the peak value of U3 exceeds the preset voltage threshold range; condition 3b is: the waveform of U3 has at least m high-frequency spike pulses within the preset time t.

[0035] Preferably, the detection conditions are: the motor speed is within a preset speed threshold range, the motor torque is within a preset torque threshold range, the motor temperature is within a preset temperature threshold range, and the reducer oil temperature is within a preset oil temperature threshold range.

[0036] Preferably, during the detection process, if the motor speed exceeds the preset speed threshold range, or the motor torque exceeds the preset torque threshold range, or the motor temperature exceeds the preset temperature threshold range, or the reducer oil temperature exceeds the preset oil temperature threshold range, the reducer bearing electrical corrosion fault detection is stopped, and the motor torque is first reduced to zero, and then the motor speed is reduced to zero.

[0037] The present invention has the following effects: (1) By measuring the voltage difference signal between the inner ring of the input shaft bearing, the inner ring of the intermediate shaft bearing and the inner ring of the output shaft bearing of the reducer and the grounding point, it is determined whether each of them has undergone electrical corrosion. The electrical corrosion fault detection of the reducer bearing is comprehensive and complete, so as to better ensure the normal operation of the reducer; if a specific type of bearing is found to be prone to electrical corrosion, the use of more electrical corrosion-resistant materials or designs can be considered in future equipment selection.

[0038] (2) n grounding points are selected for detection respectively, thus avoiding the detection error problem that may be caused by single grounding point detection (if only one grounding point is used for detection, when the grounding point is connected, it is identified that the bearing has not been corroded, and it will be determined that there is no electrical corrosion fault in the bearing. However, due to inappropriate grounding point selection, the bearing has actually been corroded, but the sudden change in voltage difference is derived but not measured, resulting in detection error). This ensures the accuracy of the detection results and realizes high-accuracy electrical corrosion fault detection, thereby improving the reliability and maintenance efficiency of the all-in-one electric drive. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Schematic diagram of the structure of the all-in-one electric drive in an embodiment of the present invention.

[0040] Figure 2 Schematic diagram of the locations of the detection points and three grounding points in the implementation of the present invention.

[0041] Figure 3 The present invention is a block diagram of the principle of an all-in-one electric drive reducer bearing electrical corrosion fault detection device according to an embodiment of the present invention.

[0042] Figure 4 The present invention is a flow chart of a method for detecting electrical corrosion faults of reducer bearings in an all-in-one electric drive according to an embodiment of the present invention.

[0043] Figure 5 This is a flow chart of another method for detecting electrical corrosion faults of reducer bearings in an all-in-one electric drive according to an embodiment of the present invention. DETAILED DESCRIPTION

[0044] In order to enable a more detailed understanding of the features and technical contents of the embodiments of the present invention, the implementation of the embodiments of the present invention is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not intended to limit the embodiments of the present invention.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein are only for the purpose of describing the embodiments of the present invention and are not intended to limit the present invention.

[0046] In the following description, reference is made to “some embodiments”, which describe a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0047] like Figures 1 to 3 As shown, the all-in-one electric drive in the embodiment of the present invention integrates at least an electronic control 1, a motor 2 and a reducer 3. A first through hole is provided on the reducer housing corresponding to the inner ring position of the input shaft bearing. A second through hole is provided on the reducer housing corresponding to the inner ring position of the intermediate shaft bearing. A third through hole is provided on the reducer housing corresponding to the end surface position of the large plate tooth of the output shaft.

[0048] like Figure 2 , Figure 3 As shown, the electric corrosion fault detection device for reducer bearing in the all-in-one electric drive includes: a powertrain bench (not shown in the figure) for driving the all-in-one electric drive to operate under the detection condition, a first brush probe 11 for measuring the voltage difference signal from the inner ring of the input shaft bearing (of the reducer) to the grounding point, a second brush probe 12 for measuring the voltage difference signal from the inner ring of the intermediate shaft bearing (of the reducer) to the grounding point, a third brush probe 13 for measuring the voltage difference signal from the inner ring of the output shaft bearing (of the reducer) to the grounding point, a signal acquisition and display module 4 whose grounding terminal can be electrically connected to the grounding point, and a fault identification module 5 for identifying whether there is an electric corrosion fault of the bearing. The signal acquisition and display module 4 obtains and displays the voltage difference signal from the inner ring of the input shaft bearing to the grounding point from the first brush probe 11, the signal acquisition and display module 4 obtains and displays the voltage difference signal from the inner ring of the intermediate shaft bearing to the grounding point from the second brush probe 12, and the signal acquisition and display module 4 obtains and displays the voltage difference signal from the inner ring of the output shaft bearing to the grounding point from the third brush probe 13. The fault identification module 5 determines whether electrical corrosion occurs in the input shaft bearing, the intermediate shaft bearing and the output shaft bearing, and whether there is an electrical corrosion fault based on the voltage difference signal from the inner ring of the input shaft bearing to the grounding point, the voltage difference signal from the inner ring of the intermediate shaft bearing to the grounding point and the voltage difference signal from the inner ring of the output shaft bearing to the grounding point transmitted by the signal acquisition and display module 4.

[0049] In some embodiments, the first brush probe 11, the second brush probe 12, and the third brush probe 13 are all flexible low-friction brush probes, which can sensitively capture the small voltage anomaly of the bearing in the early stage of electrical corrosion and monitor the voltage change of the bearing in different working conditions in real time. In some embodiments, the signal acquisition and display module 4 is an oscilloscope.

[0050] The first brush probe 11, the second brush probe 12, and the third brush probe 13 are electrically connected to the three signal input terminals of the signal acquisition and display module 4 through wires, respectively, and the signal output terminal of the signal acquisition and display module 4 is electrically connected to the fault identification module 5. There are n grounding points, and the n grounding points are arranged at intervals on the housing of the all-in-one electric drive, and n≥2.

[0051] In some embodiments, n=3, and the three grounding points are respectively a first grounding point 21, a second grounding point 22 and a third grounding point 23. The first grounding point 21 is arranged on the reducer housing between the intermediate shaft and the output shaft, the second grounding point 22 is arranged on the reducer housing close to the motor side, and the third grounding point 23 is arranged on the electronic control housing.

[0052] like Figure 4 As shown, a method for detecting electrical corrosion faults of reducer bearings in an all-in-one electric drive in an embodiment of the present invention adopts the above-mentioned device for detecting electrical corrosion faults of reducer bearings in an all-in-one electric drive, and the detection method includes: The first step is to install the all-in-one electric drive on the powertrain stand.

[0053] The second step is to pass the first brush probe 11 through the first through hole to contact the inner ring of the input shaft bearing (as the first detection point), pass the second brush probe 12 through the second through hole to contact the inner ring of the intermediate shaft bearing (as the second detection point), and pass the third brush probe 13 through the third through hole to contact the end face of the large disc tooth of the output shaft (as the third detection point). The first brush probe 11, the second brush probe 12, and the third brush probe 13 are all insulated from the reducer housing.

[0054] Since the output shaft needs to be connected to a load, the inner ring of the bearing will be disturbed if the third brush probe 13 is placed there. Therefore, the third brush probe 13 is brought into contact with the end face of the large disc tooth of the output shaft. The end face of the large disc tooth of the output shaft is close to the inner ring of the output shaft bearing, and the voltage difference is almost zero. Measuring the voltage difference from the end face of the large disc tooth of the output shaft to the grounding point is equivalent to measuring the voltage difference from the inner ring of the output shaft bearing to the grounding point.

[0055] The third step is to electrically connect the ground terminal of the signal acquisition and display module 4 to the first ground point 21, and the powertrain test bench drives the all-in-one electric drive to operate under the detection condition.

[0056] In some embodiments, the ground terminal of the signal acquisition and display module 4 can be electrically connected to the first ground point 21 by sticking the ground terminal connection wire of the signal acquisition and display module 4 to the first ground point 21 through insulating tape to form a current loop.

[0057] In some embodiments, the detection conditions are: the motor speed is within a preset speed threshold range, and the motor torque is within a preset torque threshold range, and the motor temperature is within a preset temperature threshold range, and the reducer oil temperature is within a preset oil temperature threshold range. During the detection process, if the motor speed exceeds the preset speed threshold range, or the motor torque exceeds the preset torque threshold range, or the motor temperature exceeds the preset temperature threshold range, or the reducer oil temperature exceeds the preset oil temperature threshold range, that is, when the detection conditions are not met, the reducer bearing electrical corrosion fault detection is stopped, and the motor torque is first reduced to zero, and then the motor speed is reduced to zero, and then the motor torque, motor speed, motor temperature, reducer oil temperature and other data before the shutdown can be recorded for fault phenomenon analysis.

[0058] Step 4: If the input shaft bearing, intermediate shaft bearing and output shaft bearing corresponding to the first grounding point 21 (i.e., the grounding end of the acquisition and display module 4 is electrically connected to the first grounding point 21) are all electro-corroded, it is determined that the input shaft bearing, intermediate shaft bearing and output shaft bearing are all electro-corroded, and the reduction gear bearing electro-corrosion fault detection is completed. If at least one of the input shaft bearing, intermediate shaft bearing and output shaft bearing corresponding to the first grounding point 21 is not electro-corroded, the grounding end of the signal acquisition and display module 4 is electrically connected to the second grounding point 22 (i.e., the second grounding point), and the powertrain bench drive all-in-one electric drive operates under the detection condition.

[0059] In some embodiments, when the voltage difference U1 from the inner ring of the input shaft bearing to the grounding point satisfies both conditions 1a and 1b, it indicates that the input shaft bearing has been electro-corroded. Wherein, condition 1a is: the peak value of U1 exceeds the preset voltage threshold range; condition 1b is: the waveform of U1 has at least m high-frequency spike pulses within the preset time t (high-frequency spike pulse refers to a signal with an extremely short period, extremely high frequency, and sharp waveform); m represents the preset number threshold. When the voltage difference U2 from the inner ring of the intermediate shaft bearing to the grounding point satisfies both conditions 2a and 2b, it indicates that the intermediate shaft bearing has been electro-corroded. Wherein, condition 2a is: the peak value of U2 exceeds the preset voltage threshold range; condition 2b is: the waveform of U2 has at least m high-frequency spike pulses within the preset time t. When the voltage difference U3 from the inner ring of the output shaft bearing to the grounding point satisfies both conditions 3a and 3b, it indicates that the output shaft bearing has been electro-corroded. Wherein, condition 3a is: the peak value of U3 exceeds the preset voltage threshold range; condition 3b is: the waveform of U3 has at least m high-frequency spike pulses within the preset time t.

[0060] Step 5: If the input shaft bearing, intermediate shaft bearing and output shaft bearing corresponding to the second grounding point 22 (i.e., the grounding end of the acquisition and display module 4 is electrically connected to the second grounding point 21) are all electro-corroded, it is determined that the input shaft bearing, intermediate shaft bearing and output shaft bearing are all electro-corroded, and the reduction gear bearing electro-corrosion fault detection is completed. If at least one of the input shaft bearing, intermediate shaft bearing and output shaft bearing corresponding to the second grounding point 22 is not electro-corroded, the grounding end of the signal acquisition and display module 4 is electrically connected to the third grounding point 23 (i.e., the third grounding point), and the powertrain bench drive all-in-one electric drive operates under the detection condition.

[0061] Step 6: If the input shaft bearings corresponding to the third grounding point 23, the second grounding point 22, and the first grounding point 21 (i.e., the input shaft bearings corresponding to the third grounding point 23, the input shaft bearings corresponding to the second grounding point 22, and the input shaft bearings corresponding to the first grounding point 21) do not undergo electrical corrosion, it is determined that the input shaft bearings do not have an electrical corrosion fault. If at least one of the input shaft bearings corresponding to the third grounding point 23, the second grounding point 22, and the first grounding point 21 undergoes electrical corrosion, it is determined that the input shaft bearings have an electrical corrosion fault. If the intermediate shaft bearings corresponding to the third grounding point 23, the second grounding point 22, and the first grounding point 21 (i.e., the intermediate shaft bearings corresponding to the third grounding point 23, the intermediate shaft bearings corresponding to the second grounding point 22, and the intermediate shaft bearings corresponding to the first grounding point 21) do not undergo electrical corrosion, it is determined that the intermediate shaft bearings do not have an electrical corrosion fault. If at least one of the intermediate shaft bearings corresponding to the third grounding point 23, the second grounding point 22, and the first grounding point 21 undergoes electrical corrosion, it is determined that the intermediate shaft bearings have an electrical corrosion fault. If the output shaft bearings corresponding to the third grounding point 23, the second grounding point 22, and the first grounding point 21 (i.e., the output shaft bearings corresponding to the third grounding point 23, the output shaft bearings corresponding to the second grounding point 22, and the output shaft bearings corresponding to the first grounding point 21) are not electro-corroded, it is determined that there is no electro-corrosion fault in the output shaft bearings. If at least one of the output shaft bearings corresponding to the third grounding point 23, the second grounding point 22, and the first grounding point 21 is electro-corroded, it is determined that there is an electro-corrosion fault in the output shaft bearings.

[0062] Three grounding points are selected for testing separately, which avoids the detection errors that may be caused by single grounding point testing and ensures the accuracy of the test results. It realizes high-accuracy electrical corrosion fault detection, thereby improving the reliability and maintenance efficiency of the all-in-one electric drive.

[0063] like Figure 5 As shown, another method for detecting electrical corrosion faults of reducer bearings in an all-in-one electric drive in an embodiment of the present invention adopts the above-mentioned device for detecting electrical corrosion faults of reducer bearings in an all-in-one electric drive, and the detection method comprises: The first step is to install the all-in-one electric drive on the powertrain stand.

[0064] The second step is to pass the first brush probe 11 through the first through hole to contact the inner ring of the input shaft bearing (as the first detection point), pass the second brush probe 12 through the second through hole to contact the inner ring of the intermediate shaft bearing (as the second detection point), and pass the third brush probe 13 through the third through hole to contact the end face of the large disc tooth of the output shaft (as the third detection point). The first brush probe 11, the second brush probe 12, and the third brush probe 13 are all insulated from the reducer housing.

[0065] The third step is to electrically connect the ground terminal of the signal acquisition and display module 4 to the first ground point 21, and the powertrain test bench drives the all-in-one electric drive to operate under the detection condition.

[0066] Step 4: If the input shaft bearing corresponding to the first grounding point 21 undergoes electrical corrosion, it is determined that the input shaft bearing has an electrical corrosion fault. If the intermediate shaft bearing corresponding to the first grounding point 21 undergoes electrical corrosion, it is determined that the intermediate shaft bearing has an electrical corrosion fault. If the output shaft bearing corresponding to the first grounding point 21 undergoes electrical corrosion, it is determined that the output shaft bearing has an electrical corrosion fault. If at least one of the input shaft bearing, intermediate shaft bearing, and output shaft bearing corresponding to the first grounding point 21 has not undergone electrical corrosion, the grounding terminal of the signal acquisition and display module 4 is electrically connected to the second grounding point 22, and the powertrain bench drive all-in-one electric drive operates under the detection condition.

[0067] Step 5. If the input shaft bearing corresponding to the second grounding point 22 undergoes electrical corrosion, it is determined that the input shaft bearing has an electrical corrosion fault. If the intermediate shaft bearing corresponding to the second grounding point 22 undergoes electrical corrosion, it is determined that the intermediate shaft bearing has an electrical corrosion fault. If the output shaft bearing corresponding to the second grounding point 22 undergoes electrical corrosion, it is determined that the output shaft bearing has an electrical corrosion fault. If at least one of the input shaft bearing, intermediate shaft bearing, and output shaft bearing corresponding to the second grounding point 22 does not undergo electrical corrosion, the grounding terminal of the signal acquisition and display module 4 is electrically connected to the third grounding point 23, and the powertrain bench drive all-in-one electric drive operates under the detection condition.

[0068] Step 6: If the input shaft bearing corresponding to the third grounding point 23 undergoes electrical corrosion, it is determined that the input shaft bearing has an electrical corrosion fault; if the input shaft bearing corresponding to the third grounding point 23 does not undergo electrical corrosion, it is determined that the input shaft bearing does not have an electrical corrosion fault. If the intermediate shaft bearing corresponding to the third grounding point 23 undergoes electrical corrosion, it is determined that the intermediate shaft bearing has an electrical corrosion fault; if the intermediate shaft bearing corresponding to the third grounding point 23 does not undergo electrical corrosion, it is determined that the intermediate shaft bearing does not have an electrical corrosion fault. If the output shaft bearing corresponding to the third grounding point 23 undergoes electrical corrosion, it is determined that the output shaft bearing has an electrical corrosion fault; if the output shaft bearing corresponding to the third grounding point 23 does not undergo electrical corrosion, it is determined that the output shaft bearing does not have an electrical corrosion fault.

[0069] In this detection method, starting from the first grounding point 21, if a bearing has electrical corrosion, it is considered that the bearing has an electrical corrosion fault, and the electrical corrosion fault detection of the bearing is completed. When switching to the next grounding point detection, there is no need to judge the bearing that has already had an electrical corrosion fault, which saves time and has higher detection efficiency.

[0070] In addition, the tester can also observe and analyze the waveforms of the voltage differences U1, U2, and U3 through the signal acquisition and display module 4, and conduct in-depth analysis of the extracted features to determine the nature and severity of the electrical corrosion fault. For example, by analyzing the frequency and duration of abnormal peaks, the development speed and potential impact of electrical corrosion can be determined, and prevention and maintenance strategies can also be formulated based on the results of fault diagnosis.

[0071] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A device for detecting electrical corrosion faults of reducer bearings in an all-in-one electric drive, wherein the all-in-one electric drive integrates at least an electric control (1), a motor (2) and a reducer (3); the detection device comprises a powertrain bench for driving the all-in-one electric drive to operate under a detection condition; characterized in that: Also includes: A first brush probe (11) for measuring a voltage difference signal from an inner ring of an input shaft bearing to a grounding point, a second brush probe (12) for measuring a voltage difference signal from an inner ring of an intermediate shaft bearing to a grounding point, a third brush probe (13) for measuring a voltage difference signal from an inner ring of an output shaft bearing to a grounding point, a signal acquisition and display module (4) whose grounding end can be electrically connected to the grounding point, and a fault identification module (5) for identifying whether a bearing electrical corrosion fault exists; the first brush probe (11), the second brush probe (12), and the third brush probe (13) are electrically connected to three signal input ends of the signal acquisition and display module (4) through wires, respectively, and the signal output end of the signal acquisition and display module (4) is electrically connected to the fault identification module (5); wherein there are n grounding points, and the n grounding points are arranged at intervals on the housing of the all-in-one electric drive, and n≥2.

2. The all-in-one electric drive reducer bearing electrical corrosion fault detection device according to claim 1, characterized in that: The n=3, the three grounding points are respectively a first grounding point (21), a second grounding point (22) and a third grounding point (23), the first grounding point (21) being arranged on the reducer housing between the intermediate shaft and the output shaft, the second grounding point (22) being arranged on the reducer housing close to the motor side, and the third grounding point (23) being arranged on the electronic control housing.

3. The all-in-one electric drive reducer bearing electrical corrosion fault detection device according to claim 1, characterized in that: The signal acquisition and display module (4) is an oscilloscope.

4. A method for detecting electrical corrosion faults of reducer bearings in an all-in-one electric drive, using a detection device as described in any one of claims 1 to 3, characterized in that: The detection method comprises: Install the all-in-one electric drive on the powertrain bench; The first brush probe (11) is in contact with the inner ring of the input shaft bearing, the second brush probe (12) is in contact with the inner ring of the intermediate shaft bearing, and the third brush probe (13) is in contact with the end face of the large disc tooth of the output shaft; The grounding terminal of the signal acquisition and display module (4) is electrically connected to the i-th grounding point, the powertrain test bench drive multi-in-one electric drive is operated under the detection condition, and the fault identification module (5) identifies whether the input shaft bearing, the intermediate shaft bearing and the output shaft bearing corresponding to the i-th grounding point are electro-corroded according to the voltage difference signal from the inner ring of the input shaft bearing to the grounding point, the voltage difference signal from the inner ring of the intermediate shaft bearing to the grounding point and the voltage difference signal from the inner ring of the output shaft bearing to the grounding point transmitted by the signal acquisition and display module (4); wherein i is sequentially taken to be all integers from 1 to n; If the input shaft bearings corresponding to the n grounding points do not suffer from electrical corrosion, the fault identification module (5) determines that the input shaft bearings do not suffer from electrical corrosion faults, otherwise it determines that the input shaft bearings suffer from electrical corrosion faults; If the intermediate shaft bearings corresponding to the n grounding points do not suffer from electrical corrosion, the fault identification module (5) determines that the intermediate shaft bearings do not suffer from electrical corrosion faults, otherwise it determines that the intermediate shaft bearings suffer from electrical corrosion faults; If the output shaft bearings corresponding to the n grounding points do not suffer from electrical corrosion, the fault identification module (5) determines that the output shaft bearings do not suffer from electrical corrosion faults; otherwise, the fault identification module determines that the output shaft bearings suffer from electrical corrosion faults.

5. The method for detecting electrical corrosion faults of reducer bearings in an all-in-one electric drive according to claim 4 is characterized in that: A first through hole is provided on the reducer housing at a position corresponding to the inner ring of the input shaft bearing, and the first brush probe (11) passes through the first through hole and contacts the inner ring of the input shaft bearing, and is insulated from the reducer housing; A second through hole is provided on the reducer housing at a position corresponding to the inner ring of the intermediate shaft bearing, and the second brush probe (12) passes through the second through hole and contacts the inner ring of the intermediate shaft bearing, and is insulated from the reducer housing; A third through hole is provided on the reducer housing at a position corresponding to the end face of the large disc tooth of the output shaft, and the third brush probe (13) passes through the third through hole and contacts the end face of the large disc tooth of the output shaft, and is insulated from the reducer housing.

6. The method for detecting electrical corrosion faults of reducer bearings in an all-in-one electric drive according to claim 5, characterized in that: When n=3, and the three grounding points are respectively a first grounding point (21), a second grounding point (22), and a third grounding point (23), the grounding end of the signal acquisition and display module (4) is electrically connected to the first grounding point (21); If the input shaft bearing, the intermediate shaft bearing and the output shaft bearing corresponding to the first grounding point (21) all experience electrical corrosion, it is determined that the input shaft bearing, the intermediate shaft bearing and the output shaft bearing all have electrical corrosion faults; otherwise, the grounding terminal of the signal acquisition and display module (4) is electrically connected to the second grounding point (22); If the input shaft bearing, the intermediate shaft bearing and the output shaft bearing corresponding to the second grounding point (22) all experience electrical corrosion, it is determined that the input shaft bearing, the intermediate shaft bearing and the output shaft bearing all have electrical corrosion faults; otherwise, the grounding terminal of the signal acquisition and display module (4) is electrically connected to the third grounding point (23); If the input shaft bearings corresponding to the third grounding point (23), the second grounding point (22), and the first grounding point (21) do not suffer from electrical corrosion, it is determined that the input shaft bearings do not suffer from electrical corrosion faults; otherwise, it is determined that the input shaft bearings suffer from electrical corrosion faults; If the intermediate shaft bearings corresponding to the third grounding point (23), the second grounding point (22), and the first grounding point (21) do not suffer from electrical corrosion, it is determined that the intermediate shaft bearings do not suffer from electrical corrosion faults; otherwise, it is determined that the intermediate shaft bearings suffer from electrical corrosion faults; If the output shaft bearings corresponding to the third grounding point (23), the second grounding point (22), and the first grounding point (21) do not suffer from electrical corrosion, it is determined that the output shaft bearings do not suffer from electrical corrosion faults; otherwise, it is determined that the output shaft bearings suffer from electrical corrosion faults.

7. The method for detecting electrical corrosion faults of reducer bearings in an all-in-one electric drive according to claim 5, characterized in that: When n=3, and the three grounding points are respectively a first grounding point (21), a second grounding point (22), and a third grounding point (23), the grounding end of the signal acquisition and display module (4) is electrically connected to the first grounding point (21); If the input shaft bearing corresponding to the first grounding point (21) undergoes electrical corrosion, it is determined that the input shaft bearing has an electrical corrosion fault; if the intermediate shaft bearing corresponding to the first grounding point (21) undergoes electrical corrosion, it is determined that the intermediate shaft bearing has an electrical corrosion fault; if the output shaft bearing corresponding to the first grounding point (21) undergoes electrical corrosion, it is determined that the output shaft bearing has an electrical corrosion fault; If at least one of the input shaft bearing, the intermediate shaft bearing and the output shaft bearing corresponding to the first grounding point (21) has not been subjected to electrical corrosion, the grounding end of the signal acquisition and display module (4) is electrically connected to the second grounding point (22); If the input shaft bearing corresponding to the second grounding point (22) undergoes electrical corrosion, it is determined that the input shaft bearing has an electrical corrosion fault; if the intermediate shaft bearing corresponding to the second grounding point (22) undergoes electrical corrosion, it is determined that the intermediate shaft bearing has an electrical corrosion fault; if the output shaft bearing corresponding to the second grounding point (22) undergoes electrical corrosion, it is determined that the output shaft bearing has an electrical corrosion fault; If at least one of the input shaft bearing, the intermediate shaft bearing, and the output shaft bearing corresponding to the second grounding point (22) has not been subjected to electrical corrosion, the grounding end of the signal acquisition and display module (4) is electrically connected to the third grounding point (23); If the input shaft bearing corresponding to the third grounding point (23) undergoes electrical corrosion, it is determined that the input shaft bearing has an electrical corrosion fault; if the input shaft bearing corresponding to the third grounding point (23) does not undergo electrical corrosion, it is determined that the input shaft bearing does not have an electrical corrosion fault; If the intermediate shaft bearing corresponding to the third grounding point (23) undergoes electrical corrosion, it is determined that the intermediate shaft bearing has an electrical corrosion fault; if the intermediate shaft bearing corresponding to the third grounding point (23) does not undergo electrical corrosion, it is determined that the intermediate shaft bearing does not have an electrical corrosion fault; If the output shaft bearing corresponding to the third grounding point (23) undergoes electrical corrosion, it is determined that the output shaft bearing has an electrical corrosion fault; if the output shaft bearing corresponding to the third grounding point (23) does not undergo electrical corrosion, it is determined that the output shaft bearing does not have an electrical corrosion fault.

8. The method for detecting electrical corrosion faults of reducer bearings in an all-in-one electric drive according to any one of claims 4 to 7, characterized in that: If the voltage difference U1 from the inner ring of the input shaft bearing to the grounding point satisfies both conditions 1a and 1b, it indicates that the input shaft bearing has been electro-corroded; wherein condition 1a is: the peak value of U1 exceeds the preset voltage threshold range; condition 1b is: the waveform of U1 has at least m high-frequency spike pulses within the preset time t; m represents the preset number threshold; If the voltage difference U2 from the inner ring of the intermediate shaft bearing to the grounding point satisfies both conditions 2a and 2b, it indicates that the intermediate shaft bearing has been electro-corroded; wherein condition 2a is: the peak value of U2 exceeds the preset voltage threshold range; and condition 2b is: the waveform of U2 has at least m high-frequency spike pulses within the preset time t; If the voltage difference U3 from the inner ring of the output shaft bearing to the grounding point satisfies both conditions 3a and 3b, it indicates that electrical corrosion occurs in the output shaft bearing; wherein condition 3a is: the peak value of U3 exceeds the preset voltage threshold range; and condition 3b is: the waveform of U3 has at least m high-frequency spike pulses within the preset time t.

9. The method for detecting electrical corrosion faults of reducer bearings in an all-in-one electric drive according to claim 8, characterized in that: The detection conditions are: the motor speed is within a preset speed threshold range, the motor torque is within a preset torque threshold range, the motor temperature is within a preset temperature threshold range, and the reducer oil temperature is within a preset oil temperature threshold range.

10. The method for detecting electrical corrosion faults of reducer bearings in an all-in-one electric drive according to claim 9, characterized in that: During the detection process, if the motor speed exceeds the preset speed threshold range, or the motor torque exceeds the preset torque threshold range, or the motor temperature exceeds the preset temperature threshold range, or the reducer oil temperature exceeds the preset oil temperature threshold range, the reducer bearing electrical corrosion fault detection is stopped, and the motor torque is first reduced to zero, and then the motor speed is reduced to zero.

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