A waterproof and dustproof dynamic durability test device and test method for a multi-in-one electric drive assembly

Abstract

The present application relates to the technical field of electric machines, and particularly relates to a kind of waterproof and dustproof dynamic endurance test device and test method of all-in-one electric drive assembly, the device includes: closed integrated test cavity module, for providing closed test space;Dynamic load working condition simulation rack module, for fixing the electric drive assembly to be measured, and by the dynamic sealing output shaft through structure to the electric drive assembly to be measured with speed, torque and vibration;Waterproof and dustproof coupling control module, for adjusting the spray parameters and dust suspension parameters in test cavity, to simulate vehicle external water dust working condition, high-low temperature cycle control module, for adjusting the ambient temperature in the test cavity, and support in the preset temperature range to carry out fast temperature change and / or step temperature change cycle;Micro-invasive real-time monitoring and positioning module, including distributed sensing unit and processing unit.The present application realizes the accurate traceability to electric drive assembly by constructing the test environment of load, temperature and water dust medium coupling.

Description

Technical Field

[0001] This application relates to the field of motor technology, and in particular to a waterproof and dustproof dynamic durability testing device and test method for an all-in-one electric drive assembly. Background Technology

[0002] As new energy vehicle electric drive systems develop towards higher integration and higher power density, all-in-one electric drive assemblies have become the mainstream solution. In actual driving, electric drive assemblies are exposed to complex environments such as rain, wading, dust, and alternating high and low temperatures. The reliability of sealing structures such as housing splicing surfaces, bearing oil seals, and wiring harness terminals directly affects the safety of the entire vehicle.

[0003] Currently, the industry primarily verifies the waterproof and dustproof performance of electric drive assemblies based on the static protection test scheme in national standards. This involves conducting spray or dust intrusion tests under normal temperature and static conditions with the electric drive stopped, unloaded, and vibration-free. After the test, the pass rate is determined by disassembly, insulation testing, or observation of internal water and dust accumulation. This traditional approach has significant drawbacks: First, the test conditions are severely disconnected from actual vehicle conditions, failing to simulate the real-world conditions of high-speed rotation of the electric drive, dynamic torque fluctuations, road vibrations, and temperature deformation. This results in many micro-failures in the seals that only surface under dynamic stress going undetected. Second, only macroscopic inspections can be performed after the test, making it impossible to monitor the micro-intrusion process of water vapor and dust in real time, let alone pinpoint the specific stage of failure or the specific sealing point. Third, waterproof, dustproof, and high / low temperature tests are independent of each other, making it impossible to achieve multi-stress coupled loading, resulting in low test coverage and long testing cycles. Fourth, it is difficult to identify gradual, micro-level media intrusion. The long-term accumulation of these latent defects can lead to reliability issues such as bearing corrosion and insulation degradation, which cannot be detected in advance during the R&D phase.

[0004] Therefore, existing static protection testing methods can no longer meet the R&D iteration and reliability verification needs of highly integrated electric drive assemblies. Summary of the Invention

[0005] The purpose of this invention is to provide a multi-functional electric drive assembly waterproof and dustproof dynamic durability testing device and test method to solve the technical problems in the prior art, such as the mismatch between the electric drive assembly protection test conditions and the actual vehicle conditions, the inability to monitor the sealing failure process in real time, the inability to accurately trace the source of failure, and the inability to couple multiple environmental stresses.

[0006] This invention provides the following solution: In a first aspect, this application provides a dynamic durability testing device for waterproof and dustproof all-in-one electric drive assemblies, comprising: A closed integrated test chamber module is used to provide a closed test space, and its side walls are equipped with a dynamic sealing output shaft through structure; The dynamic load condition simulation bench module is used to fix the electric drive assembly under test and apply speed, torque and vibration to the electric drive assembly under test through the dynamic sealed output shaft through structure to simulate vehicle driving conditions. A waterproof and dustproof coupling control module is used to adjust the spray parameters and dust suspension parameters inside the test chamber to simulate the water and dust conditions outside the vehicle. The spray parameters include spray water pressure, spray angle, spray duration and spray area; the dust suspension parameters include dust concentration, suspension duration and airflow velocity. The high and low temperature cycle control module is used to adjust the ambient temperature inside the test chamber and supports rapid temperature change and / or stepped temperature change cycle within a preset temperature range. A micro-intrusion real-time monitoring and location module includes: A distributed sensing unit is arranged at multiple preset sealing points of the electric drive assembly under test, for real-time acquisition of media intrusion signals at each point, wherein the media intrusion signals include at least humidity and / or dust concentration. The processing unit, connected to the distributed sensing unit, is used to receive intrusion signals and their location information from each of the distributed sensing units, and to determine the source location of the medium intrusion based on a preset spatial diffusion model and the temporal changes of the intrusion signals.

[0007] Furthermore, the medium intrusion signal also includes the signal change rate of the humidity and / or dust concentration.

[0008] Furthermore, the processing unit is used to compare the rate of change of the signals from different distributed sensing units, and based on the spatial diffusion model, to determine the location of the sensing unit where the rate of change of the signal changes first and the trend of change is strongest within a preset time window as the source location of the medium intrusion.

[0009] Furthermore, the processing unit is also used to generate a priority list containing multiple potential intrusion points based on the medium diffusion direction determined by the spatial diffusion model, and the priority list is sorted according to the probability that each point is identified as a source of medium intrusion.

[0010] Furthermore, the processing unit is used to map the position coordinates of each of the distributed sensing units and the intrusion signal to a three-dimensional spatial model, and to fit the spatiotemporal propagation process of the intrusion signal inside the electric drive assembly under test by solving the diffusion equation, so as to trace the medium diffusion path and thus determine the source location of the medium intrusion.

[0011] Furthermore, the distributed sensing unit includes a miniature humidity sensor and a trace dust sensor. The miniature humidity sensor and the trace dust sensor are embedded in one or more of the following locations of the electric drive assembly under test: the front cover oil seal, the rear cover sealing surface, the housing splicing and pressing surface, the wiring harness terminal sealing position, and the reducer bearing sealing position.

[0012] Furthermore, the side wall of the sealed integrated test chamber module is equipped with a dynamic sealing output shaft through structure, which is used to keep the chamber sealed when the dynamic load condition simulation bench module is connected to the electric drive assembly under test.

[0013] Furthermore, the dynamic sealed output shaft through structure includes a high-speed rotating oil seal installed close to the inner wall of the sealed integrated test chamber module, and a labyrinth sealing ring disposed on the outside of the high-speed rotating oil seal.

[0014] Furthermore, the preset temperature range of the high and low temperature cycle control module is -40℃ to 125℃, and the temperature change cycle it supports includes single cycle and / or multiple alternating cycles.

[0015] Secondly, the present invention provides a dynamic durability test method for waterproof and dustproof all-in-one electric drive assembly, comprising: The electric drive assembly under test is fixed inside the sealed integrated test chamber module, and a transmission connection is completed with the dynamic load condition simulation bench module. The dynamic load condition simulation test bench module is activated to apply preset speed, torque, and vibration to the electric drive assembly under test; The waterproof and dustproof coupling control module and the high and low temperature cycle control module are started simultaneously, and the water and dust environment loading and temperature cycle are alternately completed according to the preset working conditions. The intrusion monitoring and location module collects media intrusion signals at each preset sealing point in real time, and the processing unit determines the source location of the media intrusion based on a preset spatial diffusion model and the temporal changes of the intrusion signals.

[0016] The above solution achieves the following beneficial technical effects: by synchronously simulating the coupled conditions of electric drive under load, vibration, temperature alternation, and water and dust intrusion, the actual service environment of the vehicle is fully reproduced, effectively detecting potential micro-failures in the seals under dynamic stress, and solving the problems of missed detection and inaccurate data in traditional static testing.

[0017] By employing a miniature sensor array distributed at weak points in the seal for high-frequency real-time monitoring throughout the entire process, combined with a time-series analysis algorithm based on a spatial diffusion model, it can capture minute, gradual intrusions in real time during the test and output a list of intrusion source locations and priorities, accurately locating failure points and the time periods in which they occur, providing direct data support for the optimization of the sealing structure.

[0018] By integrating dynamic load simulation, wide temperature range temperature change, water and dust environment simulation, and real-time monitoring of trace intrusion into the same sealed cavity, multi-field coupling durability testing can be completed in one clamping, eliminating the need for multiple device switching and repeated clamping, thus significantly shortening the R&D verification cycle. Attached Figure Description

[0019] Figure 1 A schematic diagram of the structure of a dynamic durability testing device for a multi-functional electric drive assembly that is waterproof and dustproof is shown according to an embodiment of the present invention.

[0020] Figure 2 A flowchart of a dynamic durability test method for waterproofing and dustproofing of an all-in-one electric drive assembly according to an embodiment of the present invention is shown. Detailed Implementation

[0021] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be understood that the terms "front," "rear," "axial," etc., indicating orientation or positional relationships are based on the orientation that the operator is accustomed to facing during testing, and are only for the convenience and simplification of description. They do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. Furthermore, the terms "installation," "connection," and "fixing" should be interpreted broadly, for example, referring to a fixed connection, a detachable connection, or an integral connection, unless otherwise explicitly specified and limited.

[0023] To make the objectives, technical solutions, and advantages of the present invention clearer, the following detailed description of the waterproof and dustproof dynamic durability testing device and test method for the all-in-one electric drive assembly provided by the present invention is provided in conjunction with specific embodiments and accompanying drawings.

[0024] Please see Figure 1 As shown, it is a structural schematic diagram of the multi-in-one electric drive assembly waterproof and dustproof dynamic durability testing device of the present invention. The device specifically includes: a sealed integrated test chamber module, a dynamic load condition simulation bench module, a waterproof and dustproof coupling control module, a high and low temperature cycle control module, and a micro-intrusion real-time monitoring and positioning module.

[0025] A sealed integrated test chamber module is used to provide a closed test space. In this embodiment, the sealed integrated test chamber module adopts a high-strength pressure-resistant sealed sheet metal structure, and has the overall characteristics of being waterproof, dustproof, heat-insulating, and pressure-resistant. It can form an independent and closed test space inside, unaffected by external environmental interference.

[0026] The sealed integrated test chamber module mainly includes a dynamically sealed output shaft through-structure, an adjustable tooling bracket, and a wire harness sealing interface. The dynamically sealed output shaft through-structure, located on the side wall of the chamber, allows the drive shaft of the dynamic load condition simulation bench module to pass through the chamber wall and connect with the electric drive assembly under test inside the chamber, while maintaining the chamber's seal. In this embodiment, the dynamically sealed output shaft through-structure consists of a high-speed rotating oil seal and a labyrinth sealing ring.

[0027] The high-speed rotating oil seal is installed close to the inner wall of the cavity. As the main sealing element, its lip fits tightly with the drive shaft through which it passes, forming the first barrier against media such as water and dust when the drive shaft rotates at high speed.

[0028] The labyrinth sealing ring is located on the outside of the high-speed rotating oil seal, and its interior is machined with several narrow and tortuous gap channels. During the test, the electric drive assembly under test is in a complex operating condition with high-speed operation, high-pressure spraying, and temperature alternation within the cavity. The high-speed rotating oil seal first seals and blocks most of the medium; if a trace amount of medium breaks through the high-speed rotating oil seal, this medium will enter the tortuous gaps of the labyrinth sealing ring. As it passes through the narrow channels step by step, the flow rate gradually decreases and the pressure gradually dissipates, eventually being completely blocked and unable to enter or escape from the cavity.

[0029] Through the combined effect of the main seal of the high-speed rotating oil seal and the auxiliary seal of the labyrinth sealing ring, this dynamic sealing output shaft through-hole structure can maintain the dynamic airtightness of the cavity under harsh conditions of dynamic operation, temperature change and media erosion, and eliminate test errors caused by seal failure at the through-hole position.

[0030] An adjustable fixture bracket, fixedly mounted on the base plate inside the cavity, is used for securely clamping and fixing the electric drive assembly under test. The mounting position and clamping distance of this adjustable fixture bracket can be flexibly adjusted according to the different dimensions and power ratings of the electric drive assembly under test, making it adaptable to various specifications of all-in-one electric drive assemblies. At the same time, the adjustable fixture bracket has sufficient structural strength to withstand extreme test conditions such as high-pressure spraying, dust suspension, and wide-range temperature change cycling, providing a stable and reliable mechanical fixing foundation for the entire coupling test process.

[0031] The wire harness sealing interface, located on the side wall or top of the cavity, allows the power supply and signal wire harnesses of the electric drive assembly under test to pass through the cavity wall and connect to the external power supply and control system. The interface is filled with a sealing ring or sealant to maintain the overall airtightness of the cavity even after the wire harness has passed through.

[0032] A dynamic load condition simulation bench module is used to fix the electric drive assembly under test and apply speed, torque, and vibration to the electric drive assembly under test to simulate vehicle driving conditions. In this embodiment, the dynamic load condition simulation bench module includes a first dynamometer, a second dynamometer, a first torque-speed sensor, a second torque-speed sensor, and a vibration simulation component.

[0033] Both the first and second dynamometers are located outside the sealed integrated test chamber module. The shaft of the first dynamometer is driven through a dynamically sealed output shaft through-structure on one side wall of the chamber via a first half-shaft, connecting to one output half-shaft interface of the electric drive assembly under test inside the chamber. The shaft of the second dynamometer is driven through a dynamically sealed output shaft through-structure on the other side wall of the chamber via a second half-shaft, connecting to the other output half-shaft interface of the electric drive assembly under test. Both the first and second dynamometers support dual closed-loop control of speed and torque, enabling them to work together to accurately simulate the power output state of a vehicle under various driving conditions, including idling, constant speed, acceleration, deceleration, alternating load, and impact load. Depending on the testing requirements, the speed can be continuously adjusted from zero to the maximum speed of the electric drive assembly under test, and the torque can be dynamically applied from zero to the peak torque range.

[0034] The first torque and speed sensor is connected in series on the transmission link between the first dynamometer and the electric drive assembly under test, and the second torque and speed sensor is connected in series on the transmission link between the second dynamometer and the electric drive assembly under test. They are used to measure the torque and speed values ​​transmitted by each transmission link in real time and accurately, providing feedback signals for closed-loop control, and also providing operating parameters for test data recording.

[0035] The vibration simulation component is fixedly mounted on the connection surface between the adjustable fixture bracket and the electric drive assembly under test (EVA). It is used to directly apply adjustable high-frequency micro-amplitude vibrations to the EVA assembly. This vibration simulation component can employ an electromagnetic exciter, capable of replicating the bumpy vibrations generated when a vehicle travels on different road surfaces. By directly mounting the vibration simulation component on the fixed connection surface of the EVA assembly under test, the vibration excitation can be transmitted directly to the housing of the EVA assembly under test via the shortest path. This causes the sealing structures, such as the sealing rings and bearing oil seals, to continuously generate minute dynamic deformations and gap fluctuations consistent with actual vehicle operation during the test. This fundamentally solves the problem of sealing defects not being exposed due to the lack of vibration stress in traditional static testing.

[0036] During testing, the first dynamometer, the second dynamometer, and the vibration simulation component work synchronously, so that the electric drive assembly under test is subjected to dynamic load torque on both sides while being superimposed with vibration excitation, thus fully replicating the real dynamic mechanical environment of the whole vehicle.

[0037] A waterproof and dustproof coupling control module is used to adjust the spray parameters and dust suspension parameters within the test chamber, and supports alternating coupling cycles of water and dust to simulate external water and dust conditions of a vehicle. The spray parameters include spray water pressure, spray angle, spray duration, and spray area; the dust suspension parameters include dust concentration, suspension duration, and airflow velocity. In this embodiment, the waterproof and dustproof coupling control module integrates an adjustable high-pressure spray subsystem and a dust suspension circulation subsystem.

[0038] The adjustable high-pressure spray subsystem includes a high-pressure water pump, a water tank, multi-angle adjustable spray heads, and a pressure and flow control component. Multiple adjustable spray heads are distributed and installed on the inner walls of the sealed integrated test chamber module. Their spray angles can be independently adjusted in both horizontal and vertical directions, covering all critical sealed areas of the electric drive assembly under test, including the surrounding housing, output shaft penetration area, and wiring harness terminals. The spray water pressure is steplessly adjustable within a preset range; preferably, it is steplessly adjustable from 0.1 MPa to 1.5 MPa, simulating different water intensities from light rain to high-pressure washing. The spray duration and spray interval can be programmed and controlled by the control system according to a preset sequence, enabling various spray modes such as continuous spraying, intermittent spraying, and gradient pressure spraying.

[0039] The dust suspension and circulation subsystem includes a dust generator, an airflow circulation fan, and a dust concentration monitoring unit. The dust generator quantitatively releases test dust within a specified particle size range into the chamber. Preferably, the test dust is ISO12103-1 A2 fine test dust, with a particle size distribution ranging from 0.5 micrometers to 80 micrometers, and a median particle size of approximately 12 micrometers. The airflow circulation fan is located inside the chamber and uses intermittent airflow disturbance to maintain the dust in a uniform suspension state within the chamber, simulating a real dust environment of road dust and gravel splashes. The dust concentration monitoring unit collects the dust concentration value within the chamber in real time and feeds it back to the control system, achieving closed-loop precise control of the dust concentration.

[0040] The aforementioned adjustable high-pressure spray subsystem and dust suspension circulation subsystem can operate independently to perform a single waterproof test or a single dustproof test, or they can operate alternately according to a preset cycle sequence. A typical coupled cycle sequence is as follows: spraying for five minutes, pausing spraying and starting dust suspension for ten minutes, stopping dust supply and clearing dust from the cavity through the airflow circulation fan for five minutes, thus completing a complete coupled cycle. This achieves a coupled cycle test of alternating water and dust, fully replicating the complex scenarios encountered by vehicles in actual use, such as rain, road wading, and dust and gravel splashing.

[0041] The high and low temperature cycle control module is used to regulate the ambient temperature inside the test chamber and supports rapid temperature change and stepped temperature change cycles within a preset temperature range. In this embodiment, the high and low temperature cycle control module consists of a heat exchanger, a multi-point temperature acquisition unit, and an intelligent temperature control component.

[0042] The heat exchanger unit is connected to the interior of the sealed integrated test chamber module via air ducts or heat exchange coils, enabling forced heating or cooling of the air inside the chamber. Its temperature regulation range covers a wide temperature range from -40 degrees Celsius to 125 degrees Celsius, meeting the simulation needs of extreme environments from extreme cold to high temperature.

[0043] The multi-point temperature acquisition unit includes several temperature sensors, which are arranged in different positions inside the cavity and on key parts of the housing surface of the electric drive assembly under test. They are used to collect temperature data at each point in real time and feed it back to the intelligent temperature control component.

[0044] The intelligent temperature control component regulates the operating status and power output of the heat exchanger unit based on a preset temperature curve, supporting both rapid temperature change cycle and stepped temperature change cycle modes. In rapid temperature change mode, the temperature inside the chamber switches rapidly between preset high and low points to assess the fatigue resistance of the sealing structure under severe temperature shocks. In stepped temperature change mode, the temperature gradually increases or decreases according to preset steps and residence times to assess the steady-state sealing performance of the sealing structure at different temperature levels.

[0045] Through active temperature control by the high and low temperature cycle regulation module, the housing, sealing rings, gaskets, bearing oil seals, and other components of the electric drive assembly under test undergo periodic thermal expansion and contraction deformation. The superposition of this thermal expansion and contraction deformation with the vibration and torque loads applied by the dynamic load module can fully amplify the minute gap changes that may occur in the sealing structure during actual vehicle service, effectively exposing hidden sealing defects that cannot be detected by traditional static testing, and significantly improving the defect detection rate.

[0046] The intrusion detection and location module includes a distributed sensing unit and a processing unit.

[0047] A distributed sensing unit is arranged at multiple preset sealing points of the electric drive assembly under test, for real-time acquisition of media intrusion signals at each point, wherein the media intrusion signals include at least humidity and dust concentration.

[0048] In this embodiment, the distributed sensing unit specifically comprises eight miniature humidity sensors and eight micro-dust sensors. These sixteen sensors are installed using a miniature embedded mounting method, directly placed at multiple pre-defined weak sealing points of the electric drive assembly under test without damaging its original sealing structure. Specific placement locations include: one on the inner side of the front cover oil seal, one on the upper and lower inner side of the rear cover sealing surface, three evenly distributed circumferentially on the inner side of the housing splicing and pressing surface, one on the inner side of the wiring harness terminal sealing position, and two on the inner side of the reducer bearing sealing position.

[0049] Each sensing unit's probe faces the internal cavity of the electric drive assembly under test (DUT) to detect media intruding into the DUT from the corresponding sealing point. The gap between each sensing unit and the mounting hole is sealed with sealant to effectively isolate the sensing unit probe from direct interference from sprayed water and suspended dust within the sealed integrated test chamber module. This ensures that the signals acquired by the sensing units accurately reflect the media intrusion status at the sealing point, rather than the background values ​​of the chamber environment.

[0050] The three-dimensional mounting coordinates of each sensing unit on the electric drive assembly under test are pre-calibrated and stored in the processing unit. All sensing units collect humidity and dust concentration values ​​at their respective locations in real time at a sampling frequency of 100 Hz, and stream the signal data with sensor identifiers and timestamps to the processing unit.

[0051] The processing unit, connected to the distributed sensing unit, is used to receive intrusion signals and their location information from each of the distributed sensing units, and to determine the source location of the medium intrusion based on a preset spatial diffusion model and the temporal changes of the intrusion signals.

[0052] In this embodiment, the processing unit continuously receives real-time humidity and dust concentration values ​​from each distributed sensing unit at a sampling frequency of 100 Hz, and normalizes the raw signals from each sensing unit, mapping the signal values ​​of each sensing unit to a uniform zero-to-one dimension range. The normalization formula is: the normalized value equals the current sampled value minus the minimum value among the historical sampled values ​​of the sensing unit, and then divided by the difference between the maximum and minimum values ​​among the historical sampled values ​​of the sensing unit.

[0053] During the initial stabilization phase after the start of the test, i.e. before any water and dust environmental stress is applied, the processing unit collects 60 consecutive seconds of signal data from each sensor unit as baseline data. The processing unit calculates the following two statistics based on the baseline data for each sensor unit: The baseline average is equal to the arithmetic mean of all sampled values ​​within sixty seconds of the sensing unit.

[0054] The baseline standard deviation is equal to the standard deviation of all sampled values ​​of the sensing unit within sixty seconds. This baseline standard deviation represents the noise level of the sensing unit under steady-state conditions, and all subsequent threshold determinations are based on this baseline standard deviation.

[0055] The processing unit performs a first-order difference operation on the normalized signals of each sensing unit to obtain a signal rate of change sequence. Specifically, the signal rate of change at the current moment is equal to the normalized signal value at the current moment minus the normalized signal value at the previous sampling moment, divided by the sampling interval. Since the sampling frequency is 100 Hz, the sampling interval is 0.01 seconds.

[0056] The processing unit continuously monitors the signal change rate of all sensing units. When the signal change rate of any sensing unit exceeds five times the baseline standard deviation of that sensing unit for five consecutive sampling periods, i.e., fifty milliseconds, the processing unit determines that a media intrusion event has begun.

[0057] The first sensing unit that meets the triggering condition is marked as an alarm sensing unit, and the first sampling time that exceeds the threshold is recorded as the event start time.

[0058] After an event is triggered, the processing unit establishes an event data buffer and begins recording all sensor unit data within ten seconds of the event's start time. At the end of the ten-second time window, the processing unit extracts features from the data of all sensor units in the buffer. For each sensor unit, the following three feature parameters are extracted: First, response delay time. Response delay time is defined as the time elapsed from the start of the event until the signal change rate of the sensing unit first exceeds three times its own baseline standard deviation, measured in seconds. This three-times threshold is used to determine whether a single sensing unit has produced a genuine response to a leakage event. If the signal change rate of a sensing unit does not exceed this three-times threshold within the entire ten-second time window, its response delay time is recorded as ten seconds.

[0059] Second, peak rate of change. Peak rate of change is defined as the maximum value of the signal change rate of the sensing unit within a ten-second time window.

[0060] Third, cumulative intrusion. Cumulative intrusion is defined as the difference between the current normalized signal value of the sensing unit and its baseline average value at the end of a ten-second time window. This parameter is used to help determine the severity of media intrusion.

[0061] The processing unit includes all sensing units with a response delay of less than ten seconds into the candidate set. Sensing units with a response delay of ten seconds indicate that their signal change rate within the ten-second window never exceeds three times their baseline standard deviation, and they do not produce a identifiable response to leakage events; therefore, they are excluded from the candidate set.

[0062] If the candidate set is empty, the event is determined to be a false alarm, and the processing unit returns to normal monitoring status.

[0063] If there is only one sensing unit in the candidate set, the installation location of that sensing unit is directly determined as the source of media intrusion, and the process jumps to the result output step.

[0064] If the candidate set contains two or more sensing units, then continue with the following steps: The processing unit retrieves the pre-stored three-dimensional mounting coordinates of each sensor unit on the electric drive assembly under test. The origin of the coordinate system is defined at the geometric center of the electric drive assembly under test, the X-axis is along the output shaft axis of the electric drive assembly under test, the Y-axis is horizontal and perpendicular to the X-axis, and the Z-axis is vertical. Each sensor unit's coordinates in this coordinate system were measured using a coordinate measuring machine during installation and pre-loaded into the processing unit.

[0065] The processing unit calculates the Euclidean spatial distance between every two sensing units in the candidate set. For any two sensing units, the spatial distance is equal to the square root of the sum of the squares of the differences in their X, Y, and Z coordinates. The calculated spatial distances form a spatial distance matrix, with units in millimeters.

[0066] For each sensing unit in the candidate set, the processing unit assumes that the sensing unit is a source of media intrusion and calculates the average delay-distance ratio corresponding to that sensing unit. The specific calculation method is as follows: Obtain the response delay time of the assumed source sensing unit.

[0067] For each sensing unit in the candidate set other than the assumed source, the following calculations are performed: The response delay increment of the other sensing unit relative to the assumed source is calculated, which is the response delay time of the other sensing unit minus the response delay time of the assumed source. If an other sensing unit is located further upstream of the assumed source, its response delay time may be shorter than that of the assumed source, resulting in a negative response delay increment. In such cases, the processing unit automatically excludes the sensing unit from the evaluation calculation of the assumed source, as it is unlikely to be a downstream node spreading outward from the assumed source.

[0068] Calculate the spatial distance between the other sensing unit and the assumed source, a value already given by the spatial distance matrix from the previous step.

[0069] Calculate the delay-distance ratio of the other sensing unit, which is its response delay increment divided by the spatial distance between it and the assumed source, in millimeters per second.

[0070] The arithmetic mean of the delay-distance ratios of all other sensing units that were not excluded is taken to obtain the average delay-distance ratio corresponding to the assumed source.

[0071] The processing unit sorts the average delay-distance ratios of all sensor units in the candidate set. The sensor unit with the smallest average delay-distance ratio is presumed to be the most likely source of media intrusion, and its corresponding installation location coordinates are determined as the presumed source location of the media intrusion.

[0072] The processing unit normalizes the average delay-to-distance ratio of all sensing units in the candidate set, mapping it to a probability score between zero and one hundred. The specific conversion method is as follows: First, take the maximum and minimum values ​​of the average delay-distance ratio of all sensing units in the candidate set.

[0073] If the difference between the maximum and minimum values ​​is zero, meaning that the average delay-distance ratio of all sensing units is exactly the same, then the probability score of each sensing unit is set to 100 points divided by the number of sensing units in the candidate set.

[0074] If the difference between the maximum and minimum values ​​is not zero, then for any sensing unit in the candidate set, its probability score is equal to the maximum value minus the average delay-distance ratio of that sensing unit, divided by the difference between the maximum and minimum values, and finally multiplied by one hundred.

[0075] The processing unit generates a priority list containing all sensor units in the candidate set. Each entry in this list includes: sensor unit identifier, three-dimensional installation coordinates of the sensor unit, a description of the physical location of the sensor unit (i.e., which sealing point in the electric drive assembly under test it is located at), response delay time, peak rate of change, cumulative intrusion amount, and probability score. The list is arranged in descending order of probability score.

[0076] When the probability score difference between the first-ranked sensor unit and the second-ranked sensor unit in the list is greater than ten points, the processing unit identifies the location of the first-ranked sensor unit as the source of media intrusion. When the score difference is less than ten points, the processing unit marks the locations of the top two sensor units as suspected sources, notes their respective probability scores in the report, and prompts the testers to make a comprehensive judgment based on other information.

[0077] In some specific embodiments of the present invention, the processing unit can output the tracing results to the operation interface in a visual manner, for example: The main view of the interface displays the outline of the electric drive assembly under test using a 3D wireframe model, and marks the presumed source of media intrusion, which is ranked first, with a bright, flashing red sphere. If other locations are marked as suspected sources, they are marked with yellow spheres.

[0078] The sidebar displays the response delay times of all sensor units in the candidate set in the form of a bar chart. The bars are arranged from left to right in order of response delay time from shortest to longest. The physical location name of the corresponding sensor unit is marked above the bar, and the precise response delay time value is marked below the bar.

[0079] The bottom of the interface displays the signal change rate time-series curves of the top five sensor units in the form of a line graph over a 20-second period before and after the event trigger. Each curve is distinguished by a different color, with the horizontal axis representing time and the vertical axis representing the normalized signal change rate amplitude.

[0080] Simultaneously, the processing unit automatically generates a complete traceability report document. This report includes all of the following: the precise timestamp of the event's initiation, the identifier and physical location of the sensor unit that triggered the alarm, the type of intruding medium (i.e., humidity or dust concentration), a list of identifiers for all sensor units in the candidate set, a list of three-dimensional coordinates for each sensor unit, a list of response delay times for each sensor unit, complete data of the spatial distance matrix, the calculated average delay-distance ratio for each sensor unit, the probability score and final priority list for each sensor unit, and the signal change rate trend curve for each sensor unit within a 20-second time range before and after the event trigger.

[0081] Based on the above-mentioned visualization interface and traceability report, testers can quickly and accurately locate the weak sealing areas of the electric drive assembly under test and the specific operating conditions in which media intrusion failure occurs, providing accurate and traceable data support for subsequent sealing structure optimization design and manufacturing process improvement.

[0082] This embodiment also provides a dynamic durability test method for waterproofing and dustproofing of an all-in-one electric drive assembly, which uses the testing device described in any of the above embodiments. The method includes the following steps: Step S1: Fix the electric drive assembly under test inside the sealed integrated test chamber module and complete the transmission connection with the dynamic load condition simulation bench module. Step S2: Start the dynamic load condition simulation test bench module and apply preset speed, torque and vibration to the electric drive assembly under test; Step S3: Simultaneously start the waterproof and dustproof coupling control module and the high and low temperature cycle control module, and alternately complete the water and dust environment loading and temperature cycle according to the preset working conditions; In step S4, the intrusion monitoring and positioning module collects media intrusion signals at each preset sealing point in real time, and the processing unit determines the source location of the media intrusion based on the preset spatial diffusion model and the temporal changes of the intrusion signals.

[0083] The technical effectiveness of this method is illustrated below through a specific experimental case.

[0084] Test Case: Dynamic Waterproof and Dustproof Durability Test of 200 kW Three-in-One Electric Drive Assembly for Passenger Vehicles.

[0085] Test subject: A mass-produced three-in-one electric drive assembly with a peak power of 200 kilowatts, a maximum speed of 18,500 rpm, and a vehicle protection design target of IP67.

[0086] Test conditions: Dynamic operation involved a combined urban and high-speed cycle, with a speed range of 0 to 12,000 rpm and an alternating torque range of 0 to 280 Nm, superimposed with high-frequency road surface micro-vibration conditions with frequencies ranging from 10 Hz to 500 Hz and acceleration amplitudes from 0.5 g to 3 g. Temperature cycling involved rapid temperature changes from -20°C to 100°C, with each cycle lasting approximately 41 minutes, for a total of four cycles. Waterproof operation employed intermittent high-pressure spraying at a gradient of 0.3 to 0.8 MPa, covering the perimeter of the housing, the output shaft, and key areas such as wiring harness terminals. Dustproof operation maintained a dust concentration of 5 mg / m³ within the cavity, using intermittent airflow disturbance to achieve dust suspension and circulation. Sixteen miniature humidity sensors and trace dust sensors are installed at weak sealing points such as the inner side of the front cover oil seal, the inner side of the rear cover sealing surface, the inner side of the housing splicing and pressing surface, the inner side of the wiring harness terminal sealing position, and the inner side of the reducer bearing sealing position. The sampling frequency is 100 Hz to collect monitoring data throughout the process.

[0087] Experimental Procedure: First, the electric drive assembly under test was installed inside a sealed integrated test chamber module, and the half-shafts of two dynamometers were connected. All through interfaces of the chamber were sealed, and the sensor units were calibrated and the equipment performed a self-test. Then, the host computer preset a comprehensive dynamic operating condition for the entire vehicle and started the dynamic load module, causing the electric drive assembly to continuously operate under high-speed alternating load and vibration conditions to reproduce the vehicle's driving environment. Simultaneously, the high and low temperature cycle module and the waterproof and dustproof coupling module were started, and environmental loading such as temperature switching, high-pressure spraying, and dust suspension were alternately completed according to the preset operating conditions to construct a multi-field coupled test environment of dynamic mechanics, temperature deformation, and water and dust intrusion. Throughout the test, operating parameters such as electric drive speed, torque, vibration amplitude, and shell temperature were collected synchronously. At the same time, real-time data on humidity and dust concentration at each sealing point were collected at high frequency, and the processing unit performed real-time analysis using a source tracing algorithm.

[0088] Test results: When the traditional static IP protection test is used, the protection performance of the electric drive assembly is determined as qualified. After adopting the dynamic coupling test solution of the present invention, in the low-temperature vibration working condition stage of the third rapid temperature change cycle, that is, under the working condition where the cavity temperature is minus twenty degrees Celsius and the peak alternating torque applied by the dynamometer is 280 N·m, the processing unit successfully detects a medium intrusion event. The sensing unit located inside the oil seal of the output shaft has the shortest response delay time of 0.2 seconds in this event, the response delay time of the sensing unit located inside the sealing surface of the rear end cover is 1.5 seconds, and the response delay times of the three sensing units located inside the shell splicing and pressing surface are 3.2 seconds, 4.1 seconds and 5.8 seconds respectively. The calculation results of the delay-distance ratio of each sensing unit all point to the position of the output shaft oil seal. The processing unit finally determines the position of the output shaft oil seal as the source of medium intrusion, with a probability score of 95. The probability score of the second-ranked rear end cover sealing surface position is 62, and the difference is greater than 10, so it is determined as the only intrusion source. This defect cannot be exposed in traditional static tests, and the present solution can effectively identify such working condition-related micro-failure problems, providing direct test data support for subsequent oil seal structure optimization, sealing tolerance iteration, and protection reliability upgrade.

[0089] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other changes or modifications in different forms can be made based on the above description. It is impossible to exhaust all embodiments here, and any obvious changes or modifications derived from the technical solution of the present invention still remain within the protection scope of the present invention.

Claims

1. A dynamic durability testing device for waterproof and dustproof all-in-one electric drive assembly, characterized in that, include: A closed integrated test chamber module is used to provide a closed test space, and its side walls are equipped with a dynamic sealing output shaft through structure; The dynamic load condition simulation bench module is used to fix the electric drive assembly under test and apply speed, torque and vibration to the electric drive assembly under test through the dynamic sealed output shaft through structure to simulate vehicle driving conditions. A waterproof and dustproof coupling control module is used to adjust the spray parameters and dust suspension parameters inside the test chamber to simulate the water and dust conditions outside the vehicle. The spray parameters include spray water pressure, spray angle, spray duration and spray area; the dust suspension parameters include dust concentration, suspension duration and airflow velocity. The high and low temperature cycle control module is used to adjust the ambient temperature inside the test chamber and supports rapid temperature change and / or stepped temperature change cycle within a preset temperature range. A micro-intrusion real-time monitoring and location module includes: A distributed sensing unit is arranged at multiple preset sealing points of the electric drive assembly under test, for real-time acquisition of media intrusion signals at each point, wherein the media intrusion signals include at least humidity and / or dust concentration. The processing unit, connected to the distributed sensing unit, is used to receive intrusion signals and their location information from each of the distributed sensing units, and to determine the source location of the medium intrusion based on a preset spatial diffusion model and the temporal changes of the intrusion signals.

2. The all-in-one electric drive assembly waterproof and dustproof dynamic durability testing device according to claim 1, characterized in that, The medium intrusion signal also includes the rate of change of the humidity and / or dust concentration.

3. The all-in-one electric drive assembly waterproof and dustproof dynamic durability testing device according to claim 2, characterized in that, The processing unit is used to compare the rate of change of signals from different distributed sensing units, and based on the spatial diffusion model, to determine the location of the sensing unit where the rate of change of signal changes first and the trend of change is strongest within a preset time window as the source location of the medium intrusion.

4. The all-in-one electric drive assembly waterproof and dustproof dynamic durability testing device according to claim 3, characterized in that, The processing unit is also used to generate a priority list containing multiple potential intrusion points based on the medium diffusion direction determined by the spatial diffusion model. The priority list is sorted according to the probability that each point is identified as a source of medium intrusion.

5. The all-in-one electric drive assembly waterproof and dustproof dynamic durability testing device according to claim 1, characterized in that, The processing unit is used to map the position coordinates and intrusion signals of each of the distributed sensing units to a three-dimensional spatial model, and to fit the spatiotemporal propagation process of the intrusion signal inside the electric drive assembly under test by solving the diffusion equation, so as to trace the medium diffusion path and thus determine the source location of the medium intrusion.

6. The all-in-one electric drive assembly waterproof and dustproof dynamic durability testing device according to claim 1, characterized in that, The distributed sensing unit includes a miniature humidity sensor and a trace dust sensor. The miniature humidity sensor and the trace dust sensor are embedded in one or more of the following locations of the electric drive assembly under test: the front cover oil seal, the rear cover sealing surface, the housing splicing and pressing surface, the wiring harness terminal sealing position, and the reducer bearing sealing position.

7. The all-in-one electric drive assembly waterproof and dustproof dynamic durability testing device according to claim 1, characterized in that, The side wall of the sealed integrated test chamber module is equipped with a dynamic sealing output shaft through structure, which is used to keep the chamber sealed when the dynamic load condition simulation bench module is connected to the electric drive assembly under test.

8. The all-in-one electric drive assembly waterproof and dustproof dynamic durability testing device according to claim 7, characterized in that, The dynamic sealed output shaft through structure includes a high-speed rotating oil seal installed close to the inner wall of the sealed integrated test chamber module, and a labyrinth sealing ring disposed on the outside of the high-speed rotating oil seal.

9. The all-in-one electric drive assembly waterproof and dustproof dynamic durability testing device according to claim 1, characterized in that, The preset temperature range of the high and low temperature cycle control module is -40℃ to 125℃, and the temperature change cycle it supports includes single cycle and / or multiple alternating cycles.

10. A method for dynamic durability testing of waterproof and dustproof all-in-one electric drive assemblies, applied to the dynamic durability testing device for waterproof and dustproof all-in-one electric drive assemblies as described in any one of claims 1-9, characterized in that, include: The electric drive assembly under test is fixed inside the sealed integrated test chamber module, and a transmission connection is completed with the dynamic load condition simulation bench module. The dynamic load condition simulation test bench module is activated to apply preset speed, torque, and vibration to the electric drive assembly under test; The waterproof and dustproof coupling control module and the high and low temperature cycle control module are started simultaneously, and the water and dust environment loading and temperature cycle are alternately completed according to the preset working conditions. The intrusion monitoring and location module collects media intrusion signals at each preset sealing point in real time, and the processing unit determines the source location of the media intrusion based on a preset spatial diffusion model and the temporal changes of the intrusion signals.

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