New energy vehicle oil cooling motor oil circuit and spray design verification method and equipment

Abstract

This invention discloses a verification method for the oil circuit and spray design of an oil-cooled motor for new energy vehicles, comprising: installing the oil-cooled motor on a test bench and connecting the external circulation oil supply system; arranging flow and pressure sensors at key nodes of the oil circuit; setting up cameras and light sources around the motor to perform optical imaging of the oil spray and coverage; constructing a test condition matrix and conducting tests according to a preset procedure; comparing the collected images, flow, and pressure data with a simulation model to achieve model calibration; simulating vehicle operating conditions at different slopes and tilt angles by rotating the test bench; and writing the test data into a structured database for subsequent retrieval and reuse. This invention enables visualized verification of the oil circuit and spray design of the oil-cooled motor. This invention also discloses a test device.

Description

Technical Field

[0001] This invention belongs to the technical field of electric drive systems for new energy vehicles. Specifically, this invention relates to a method and equipment for verifying the oil circuit and spray design of an oil-cooled motor for new energy vehicles. Background Technology

[0002] As permanent magnet drive motors for new energy vehicles evolve towards higher speeds, higher integration, and higher efficiency, flat wire windings are being adopted by an increasing number of new energy vehicles due to their advantages such as high slot fill factor, high power density, high efficiency, and superior heat dissipation performance. However, high power density operation leads to a significant increase in internal losses (copper losses, iron losses, and mechanical losses) in the motor, and temperature rise has become a key factor restricting motor performance and lifespan.

[0003] Currently, most flat-wire motors employ water-cooled or oil-water hybrid cooling structures. The stator core is cooled via water channels, and heat exchange is achieved through oil and water channels within the casing to lower the water temperature. However, this structure presents challenges in cooling the motor's end windings. End-spraying can effectively solve this problem, with the end windings cooled by oil injection pipes or rings. However, verifying the reliability of the oil circuit design remains a challenge. Currently, CAE simulation (CFD+FEM) is primarily used to obtain preliminary oil circuit and nozzle parameters, followed by the fabrication of a metal casing prototype. Temperature rise or hot-spot tests are then conducted to evaluate the motor's cooling effect.

[0004] The existing technology has the following defects and shortcomings: a) Due to the opacity of the metal casing of the oil-cooled motor, it is impossible to directly observe the shape and splashing of the internal oil jet; the transparent components (observation window, transparent cover) of the existing device are mostly local designs, which can only observe the rotor bearing or local area of ​​the stator, and cannot simultaneously cover the key lubrication and cooling areas such as the stator winding end and the air gap between the stator and rotor.

[0005] b) A single verification process requires recasting or machining the shell, which takes 20 to 30 days and is costly; c) The experimental data is in a scattered format, making it difficult to integrate into a reusable knowledge base.

[0006] This paper provides a method for verifying the oil circuit and spray design of an oil-cooled motor for new energy vehicles, specifically on how to effectively verify the oil circuit and spray design of an oil-cooled motor for new energy vehicles, thereby improving the intuitiveness and accuracy of the test. Summary of the Invention

[0007] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention provides a method for verifying the oil circuit and spray design of an oil-cooled motor for new energy vehicles, with the purpose of effectively verifying the oil circuit and spray design of such motors and improving the intuitiveness and accuracy of the test.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for verifying the oil circuit and spray design of an oil-cooled motor for new energy vehicles, comprising the following steps: S1. Install the oil-cooled motor under test on the test bench and establish a connection between the oil-cooled motor under test and the external oil supply equipment; S2. Construct an external circulation oil supply circuit. A flow meter and a first pressure sensor are installed in the external circulation oil supply circuit. The oil outlet of the oil-cooled motor under test is connected to the flow meter. The oil outlet of the flow meter is connected to the first pressure sensor. The oil outlet of the first pressure sensor is connected to the return oil port of the external oil supply equipment. An adjustable return oil flow valve is installed on the external circulation oil supply circuit. S3. Install a second pressure sensor and a flow sensor in the oil-cooled motor under test; S4. Set up cameras in multiple field-of-view directions of the oil-cooled motor under test, and arrange a light source to excite the fluorescent tracer on the side of the camera. Inject fluorescent tracer cooling oil into the external circulation oil supply circuit, collect images of the fluorescent tracer in the fluorescent tracer cooling oil through the camera, and obtain the three-dimensional oil beam trajectory based on the images. S5. Construct a test condition matrix based on oil temperature, speed, nozzle specifications and injection angle, and perform heating, flow stabilization, sampling and imaging operations for each condition; S6. Compare the collected pressure, flow rate, and imaging data with the simulation data. Based on the comparison results, obtain the resistance and flow rate parameters of the oil circuit model, generate a calibration file, and update the simulation model. S7. Simulate the oil circuit operation under different vehicle postures by adjusting the tilt angle of the test bench, and record the corresponding test data, including pressure, flow rate and imaging data; S8. Store the test data, structural parameters and boundary conditions of each working condition in the database, and index and reuse the data through dimensionless parameters.

[0009] The light source is arranged at a predetermined angle to the optical axis of the camera to reduce interference from reflected light; the frame rate of the camera is not less than 1000fps and the resolution is not less than 1280×720.

[0010] In step S6, a deviation distribution map is generated, and parameter backfitting is performed based on the deviation distribution map.

[0011] The fluorescent tracer cooling oil is a mixture of base oil and fluorescent agent. The fluorescent agent produces visible fluorescence when excited at a preset wavelength, and the mass fraction of the fluorescent agent is 0.1% to 1%.

[0012] The base oil is a polyalphaolefin lubricating oil with a kinematic viscosity of 10-30 cSt at 40°C and a flash point of not less than 180°C. In preparing the fluorescent tracer cooling oil, after adding the fluorescent agent to the base oil, the fluorescent agent is uniformly dispersed by stirring with a magnetic stirrer for a predetermined time.

[0013] The transparent shell is made of thermoplastic.

[0014] The oil cooling assembly of the tested oil-cooled motor includes an oil injection ring and a nozzle disposed on the oil injection ring. The nozzle and the oil injection ring are connected by a flexible snap or a quick-connect interface.

[0015] In step S4, three cameras are set up and arranged on the front and left and right sides of the oil-cooled motor under test, respectively. The camera arranged on the front side is aimed at the end of the stator winding of the oil-cooled motor under test, and the cameras arranged on the left and right sides are aimed at the stator-rotor air gap (the stator-rotor air gap is the annular gap between the stator and rotor of the motor).

[0016] The present invention also provides a test device for the oil circuit and spray design verification method of the oil-cooled motor for new energy vehicles, including a test bench, a camera, a light source and an oil-cooled motor under test. The oil-cooled motor under test is set on the test bench, and the camera is respectively arranged on the front and left and right sides of the oil-cooled motor under test. The light source and the camera are arranged in the same position. The oil-cooled motor under test includes a transparent shell, which is made of thermoplastic plastic.

[0017] The distance between the camera and the oil-cooled motor under test is 300mm, and the aperture is set to F2.0.

[0018] The present invention provides a method for verifying the oil circuit and spray design of an oil-cooled motor for new energy vehicles. This method involves steps such as modifying the motor housing, injecting a soluble fluorescent dye into the oil, installing flow meters and pressure gauges, and configuring external oil supply equipment. These steps enable effective verification of the oil circuit and spray design of the oil-cooled motor for new energy vehicles. This method not only improves the intuitiveness and accuracy of the test but also provides solid data support for subsequent optimization and improvement. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a method for verifying the design of an oil circuit and spray system provided in this application; Figure 2 This is a schematic diagram of a quick-change fuel injection ring structure provided in this application; Figure 3This is a schematic diagram of an oil-cooled tilting test bench provided in this application; The markings in the above figures are: 1. Injection ring; 21. Test bench; 22. Oil-cooled motor under test; 23. External oil supply equipment; 24. Light source; 25. Camera. Detailed Implementation

[0020] To facilitate understanding of the present invention, a more comprehensive description of the present invention will be given below with reference to the accompanying drawings, which illustrate several embodiments of the present invention. However, the present invention can be implemented in different forms and is not limited to the embodiments described in the text. Rather, these embodiments are provided to make the disclosure of the present invention more thorough and complete.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly associated with those skilled in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] Firstly, such as Figure 1 As shown, this embodiment of the invention provides a method for verifying the oil circuit and spray design of an oil-cooled motor for new energy vehicles, including the following steps: S1. Install the oil-cooled motor under test on the test bench and establish a connection between the oil-cooled motor under test and the external oil supply equipment; S2. Construct an external circulation oil supply circuit. A flow meter and a first pressure sensor are installed in the external circulation oil supply circuit. The oil outlet of the oil-cooled motor under test is connected to the flow meter. The oil outlet of the flow meter is connected to the first pressure sensor. The oil outlet of the first pressure sensor is connected to the return oil port of the external oil supply equipment. An adjustable return oil flow valve is installed on the external circulation oil supply circuit. S3. A second pressure sensor and a flow sensor are arranged in the oil-cooled motor under test. The oil circuit is set inside the transparent housing. The second pressure sensor and the flow sensor are connected to the data acquisition unit through flexible cables. The data acquisition unit uses a unified clock source to synchronize all sensor signals. S4. Set up cameras in multiple fields of view of the oil-cooled motor under test, and arrange a light source to excite the fluorescent tracer on the side of the camera. Inject fluorescent tracer cooling oil into the external circulation oil supply circuit, collect images of the fluorescent tracer in the fluorescent tracer cooling oil through the camera, and obtain the three-dimensional oil jet trajectory based on the images. S5. Construct a test condition matrix based on oil temperature, speed, nozzle specifications and injection angle, and perform heating, flow stabilization, sampling and imaging operations for each condition; S6. Compare the collected pressure, flow rate, and imaging data with the simulation data. Based on the comparison results, obtain the resistance and flow rate parameters of the oil circuit model, generate a calibration file, and update the simulation model. S7. Simulate the oil circuit operation under different vehicle postures by adjusting the tilt angle of the test bench, and record the corresponding test data, including pressure, flow rate and imaging data; S8. Store the test data, structural parameters and boundary conditions of each working condition in the database, and index and reuse the data through dimensionless parameters.

[0023] Specifically, in this embodiment of the invention, the tested oil-cooled motor is an oil-cooled permanent magnet synchronous motor used in new energy vehicles. The tested oil-cooled motor includes an end cover, a transparent housing, a stator, and a rotor. The end cover is installed at one end of the transparent housing, and the stator and rotor are installed in the inner cavity of the transparent housing. The transparent housing is made of thermoplastic plastic, and an oil passage is provided inside the transparent housing. Fluorescent tracer cooling oil flows along the oil passage.

[0024] When manufacturing the transparent shell, materials that can maintain transparency and possess sufficient mechanical strength in high-temperature oil environments, such as polycarbonate (PC), are selected due to their excellent transparency, weather resistance, and processing performance. Using precision CNC machining technology, the raw material is cut and shaped into a transparent shell and end caps that perfectly match the original metal shell shape. During this process, the processing temperature and cutting speed must be strictly controlled to ensure the precision and surface finish of the transparent shell. An elastic O-ring sealing structure is used between the transparent shell and the end caps. This structure maintains an effective seal within the motor's operating temperature range, preventing oil leakage. After processing, the transparent shell undergoes rigorous multi-round alternating cold and heat tests and long-term oil immersion aging tests to verify its stability and durability under extreme conditions. Testing showed that the transparent shell did not exhibit cracks, fogging, or significant deformation, proving that its reliability fully meets the verification requirements.

[0025] In this embodiment of the invention, a lubrication-cooling test method for an oil-cooled permanent magnet synchronous motor for new energy vehicles is provided, mainly including the following steps: Transparent modification: Using oil-resistant and heat-resistant transparent materials, the motor housing and key oil circuits are replicated at a 1:1 scale; Tracer enhancement: Add a soluble fluorescent dye to the lubricating oil; Micro-sensor networks: embedding miniature flow meters and high-frequency pressure sensors at key nodes in the oil circuit; Rapid iteration: The nozzle and microchannel adopt a transparent structure; Operating conditions reproduction: The external circulation constant temperature oil supply system provides stable boundary conditions from -40℃ to 120℃ and from 0 to 30 liters / minute; Image acquisition: Using a high-speed camera in conjunction with laser sheet light technology, three-dimensional reconstruction of the oil beam is achieved; Automatic comparison: The software compares the measured data with the simulation results in real time and outputs a deviation contour map; Data archiving: Automatically generates a structured database for easy data retrieval by subsequent models.

[0026] In step S1 above, as Figure 3 As shown, when installing a specially designed oil-cooled motor, the motor under test must first be mounted on a tiltable test bench. Then, the motor is connected to the motor controller via a high-voltage wiring harness. During installation, special care must be taken to protect the rigidity of the transparent housing to prevent impacts or other potential damage during operation. Next, the oil outlet of the external oil supply device needs to be connected to the oil inlet of the oil-cooled motor under test, which is located on the transparent housing. When connecting the piping, ensure that the piping is as short as possible and without bends or angles. This minimizes the impact on the flow resistance of the cooling circuit, thereby ensuring the efficient operation of the cooling system.

[0027] In step S2 above, the oil outlet of the tested oil-cooled motor is connected to the inlet of a flow meter via a PU tube. The outlet of the flow meter is connected to the inlet of a first pressure sensor, and the outlet of the first pressure sensor is connected to the return port of an external oil supply device. The inner diameter of the PU tube is 10mm. An adjustable return flow valve is also installed on the external circulation oil supply circuit to regulate the return flow.

[0028] In this embodiment of the invention, the oil cooling assembly of the tested oil-cooled motor includes an oil injection ring and nozzles disposed on the oil injection ring. Multiple nozzles are provided, and the oil injection ring is mounted on the inner circular surface of a transparent housing. Figure 2 As shown, the oil injection ring has a circular structure and is coaxially arranged with the transparent housing. Oil channels are located inside the oil injection ring, connecting the oil passages of the transparent housing and the nozzles. These channels distribute the fluorescent tracer cooling oil in the oil passages to the various nozzles. All nozzles are evenly distributed circumferentially on the oil injection ring. The nozzles spray oil onto the rotor and stator. The nozzles are connected to the oil injection ring via elastic clips or quick-connect interfaces, facilitating nozzle replacement and improving testing efficiency. The nozzles are available in various models, covering different orifice diameters and spray angles to meet the needs of different operating conditions.

[0029] In step S3 above, a second pressure sensor and a flow sensor are placed at key locations in the oil-cooled motor under test. These key locations include the oil pump outlet, nozzle inlet, and inside the motor cavity. The second pressure and flow sensors are miniature sensors, and their housings are compatible with the oil, preventing corrosion or deformation due to prolonged immersion. The second pressure and flow sensors are connected to the control system's data acquisition unit via flexible cables. The data acquisition unit synchronizes all sensor signals using a unified clock source to ensure phase consistency during transient processes. The sensors are installed using mechanical slots and sealing rings, facilitating installation and preventing loosening. After installation, continuous operation and multiple disassembly and reassembly tests are required to verify the stability and reliability of the sensors.

[0030] like Figure 3 As shown, in step S4 above, three cameras are used, positioned at the front and left / right sides of the oil-cooled motor under test. The front camera is aimed at the stator winding end of the motor, while the left / right cameras are aimed at the stator-rotor air gap (the annular gap between the stator and rotor). The front camera can directly cover the entire radial range of the stator winding end without any other structural obstruction, capturing the overall spray distribution of the winding end. Through high-resolution imaging from the front, it is possible to visually observe whether the oil jet evenly covers all winding end areas, the diffusion pattern after the oil jet impacts the end, and whether there are any uncovered dead zones, providing direct evidence for judging the rationality of the spray angle and nozzle flow design. The two cameras on the left and right sides of the motor provide a radial lateral view of the motor, parallel to the annular plane of the stator-rotor air gap, minimizing visual obstruction and penetrating the narrow space of the air gap to capture the dynamics of the oil within the gap. Simultaneous imaging from both sides allows for precise capture of the instantaneous shape of the oil jet entering the air gap, its diffusion trajectory under high-speed rotating airflow, and the adhesion and flow state of the oil within the air gap. This verifies whether the nozzle orientation and injection pressure design enable the oil to effectively penetrate into the core area of ​​the air gap. Simultaneously, the transparent housing provides an unobstructed observation channel for the three cameras, ensuring they can directly capture the internal state of the motor. This arrangement would not be possible with a traditional metal housing.

[0031] In embodiments of the present invention, such as Figure 3As shown, an ultraviolet (UV) light source with a wavelength of 365 nm and a power of 50 W is positioned next to the camera. The UV light source is arranged at a predetermined angle of 45 degrees to the camera's optical axis to reduce interference from reflected light. When the fluorescent tracer in the oil is irradiated by the laser emitted from the light source, it emits bright fluorescence, which is captured by the high-speed camera. The high-speed camera employs a high-resolution, high-frame-rate design, enabling it to capture subtle dynamic changes in the oil stream. Through multi-angle shooting or scanning, the two-dimensional image is reconstructed into a three-dimensional oil stream trajectory. The imaging system and the data acquisition system share a trigger signal to ensure strict synchronization between the image and flow and pressure data. The entire optical path design is flexible and can be quickly adjusted to adapt to different field-of-view and resolution requirements.

[0032] In this embodiment of the invention, the camera's frame rate is not less than 1000fps and the resolution is not less than 1280×720.

[0033] In this embodiment of the invention, to improve the easy-to-observe performance of the oil, the fluorescent tracer cooling oil is a mixture of base oil and fluorescent agent. The fluorescent agent is UV-1130 fluorescent agent, which is excited at a preset wavelength of 365 nm to produce visible fluorescence. The mass fraction of the fluorescent agent is 0.1% to 1%, and preferably 0.5%. This avoids the problem of insufficient fluorescence intensity and difficulty in capturing weak signals when the concentration is too low, while also preventing fluorescent agent aggregation caused by excessively high concentration, which affects the fluidity and light transmittance of the oil. This ensures that the cooling effect of the cooling oil is consistent with the safety of motor operation, and at the same time avoids image saturation distortion caused by fluorescence overflow.

[0034] After the fluorescent agent has fully dissolved, 30 liters of fluorescent oil are injected into the external circulation system's oil tank, ensuring the oil level exceeds the pump inlet by 50mm to maintain normal system operation. Subsequently, the filler cap is closed and the air filter is tightened to prevent external dust and impurities from entering, ensuring the system's clean and stable operation.

[0035] In this embodiment of the invention, the base oil is a polyalphaolefin lubricating oil, such as PAO4 type base oil, which has a kinematic viscosity of 10-30 cSt at 40°C and a flash point of not less than 180°C. It has excellent high-temperature stability, anti-aging properties, and lubrication performance, and can withstand the high-temperature environment of motor operation for a long time.

[0036] In this embodiment of the invention, when preparing the fluorescent tracer cooling oil, after adding the fluorescent agent to the base oil, the fluorescent agent is uniformly dispersed by stirring with a magnetic stirrer for a predetermined time. The stirring speed of the magnetic stirrer is 500 rpm, and the predetermined time is 30 minutes. Using a magnetic stirring speed of 500 rpm and a stirring time of 30 minutes ensures that the fluorescent agent is uniformly dispersed in the base oil, reducing fluctuations in experimental data caused by uneven oil dispersion, and preventing the fluorescent agent from agglomerating into particulate impurities. Such impurities may clog nozzles, affect the oil jet morphology, or cause false bright spots in the image, interfering with the extraction of oil jet feature points and the accuracy of 3D reconstruction.

[0037] In this embodiment of the invention, considering the narrow air gap between the stator and rotor, the complex structure at the end of the stator winding, and the low contrast between the oil and the metal components, the fluorescent oil emits bright fluorescence after being excited by a 365nm ultraviolet light source, which can greatly improve the visual distinction between the oil jet and the motor components, enabling the camera to clearly capture the fine oil jet in the air gap and the oil penetration state in the winding gap.

[0038] In step S4 above, after the light source is started, it is continuously irradiated on the motor; the fluorescent agent in the fluorescent tracer cooling oil stably emits visible fluorescence at a wavelength of 450nm under the excitation light of 365nm wavelength; the high-speed camera is started simultaneously to capture the fluorescence images of the stator winding end and the air gap area of ​​the stator and rotor at a preset frame rate. The imaging system and the data acquisition module share the trigger signal to ensure that the image is strictly synchronized with the flow and pressure data.

[0039] In step S4 above, the raw fluorescence images acquired by each camera are preprocessed to highlight oil jet features and eliminate interference. Using image processing software, key feature points of the oil jet (such as inflection points of the oil jet edge, sampling points of the oil jet central axis, and the center point of the oil droplet contour) are extracted from each preprocessed two-dimensional image, and the two-dimensional coordinates (pixel coordinates) of these feature points in the image are recorded. The three-dimensional spatial coordinates of the acquired two-dimensional feature points are calculated. The three-dimensional coordinates of all oil jet feature points at the same time are fitted to obtain the spatial contour of the oil jet at that time. The above steps are repeated for consecutive frames to obtain the three-dimensional coordinate sequence of oil jet feature points at different times. These coordinates are concatenated in chronological order to generate the dynamic three-dimensional trajectory of the oil jet, thus reconstructing the three-dimensional oil jet trajectory.

[0040] Step S4 above is the preparation and verification stage. Fluorescent tracer cooling oil is injected into the external circulation oil supply circuit. Oil flows in the oil circuit, and through oil flow and image acquisition, it is ensured that the visualization system, oil supply system, and sensing system are in normal working condition. Pre-acquired multi-view images are used to test the accuracy of feature point matching and triangulation, verifying the successful reconstruction of the three-dimensional oil jet trajectory and proactively identifying reconstruction errors caused by algorithms or equipment layout. Furthermore, image acquisition under pre-flow conditions allows for rapid determination of whether there are leaks in the oil circuit, whether the nozzles are clogged, and whether the oil circulation is uniform, avoiding the waste of experimental resources by proceeding with basic faults into the operating condition test in step 5. Step S5, based on step S4, adjusts variables such as oil temperature, speed, and nozzle specifications according to the orthogonal operating condition matrix. Each set of operating condition tests repeats the process of oil flow → image acquisition → data recording. The images acquired at this stage are the formal experimental data used for analysis.

[0041] In step S5 above, four key factors were selected and scientifically categorized based on the critical variables affecting the oil flow characteristics and spraying effect. This ensures comprehensive coverage of the actual operating scenario and the design variable range. The four key factors include oil temperature, motor speed, nozzle specifications, and nozzle angle. An orthogonal design method was used to construct the operating condition matrix. A standard orthogonal array can be selected, where each factor at each level appears the same number of times, and any two factors are balanced in their level combinations. This ensures that the experimental data can accurately separate the independent influence of each factor on the results (flow rate, pressure, spray coverage area, and three-dimensional oil jet trajectory), avoiding analytical errors caused by variable confounding. Orthogonal design is an efficient and economical experimental design method that can comprehensively examine the influence of each factor on the experimental results within a limited number of experiments.

[0042] In step S5 above, each operating condition sequentially performs operations such as heating, flow stabilization, sampling, imaging, and data archiving. The entire testing process for each operating condition is automatically driven by the control system's program script, requiring only the initiation of the operating condition and confirmation of archiving; human intervention is minimal. When switching operating conditions, only the nozzle module needs to be replaced and the oil supply boundary conditions adjusted; there is no need to disassemble the housing or pipelines, significantly shortening the test preparation time. During the heating phase, the control system sends an oil temperature setting command to the external oil supply equipment, which then heats the fluorescent tracer cooling oil to the target temperature via its heating module. The motor continues to run during the heating process. During the steady flow phase, the control system automatically adjusts the oil supply pressure of the external oil supply equipment according to the nozzle specifications and injection angle parameters under the current operating conditions, so that the oil flow reaches the target value; at the same time, the flow and pressure sensors are pre-acquisitioned to monitor the key node parameters of the oil circuit in real time. When the flow and pressure fluctuation is less than 0.5% / min, it is determined that the steady flow has been achieved and the system automatically enters the next phase.

[0043] During the sampling phase, the control system sends a synchronous trigger signal to activate the flow sensor and pressure sensor, and collect transient data at the set sampling frequency. During the acquisition process, the sensor data is transmitted to the data acquisition unit in real time through flexible wires and stored synchronously based on the same clock source to ensure the phase consistency of the flow and pressure data.

[0044] During the imaging phase, three high-speed cameras and an ultraviolet light source are triggered synchronously with the sampling phase. The cameras acquire fluorescence images, while the light source maintains a stable excitation wavelength of 365nm, and the cameras acquire image data.

[0045] During the data archiving phase, the control system automatically stops sampling and imaging, and stores the data collected by the sensors (including flow rate and pressure), image data (including raw fluorescence images and pre-processed images), and operating parameters (including oil temperature, speed, nozzle specifications, etc.) according to the naming rule of operating condition number-time stamp; and simultaneously generates a draft operating condition report, which includes key parameter statistical values ​​and imaging quality judgment results, and automatically uploads it to the local server.

[0046] In step S6 above, after the experiment, the testing software automatically compares the measured flow rate, pressure, and spray coverage area with the simulation results point by point, generating a deviation cloud map. The deviation cloud map visually displays the distribution of differences between the measured data and the simulation results. Through backfitting technology, key parameters such as drag coefficient and flow coefficient are extracted and written into a calibration file in a unified format. The calibrated simulation model shows a significant reduction in error in subsequent aircraft model predictions, improving the accuracy and reliability of the simulation results. All data processing is automated by scripts, and reports are generated and uploaded to the data management platform within minutes for engineers to perform subsequent analysis and optimization.

[0047] In step S7 above, by flipping the test bench, the simulated tilt angles include a 30% uphill slope, a -30% downhill slope, and left and right tilts from -5° to 5°. The oil-cooled motor under test is installed on the test bench at different tilt angles for testing, which can simulate different postures of the whole vehicle.

[0048] The test bench can simulate the impact of different tilt angles encountered by a vehicle during driving on the oil-cooled motor's hydraulic system. By adjusting the tilt angle of the test bench, various slope conditions can be simulated, such as a 30% uphill slope, a -30% downhill slope, and slope variations on flat roads. It also considers possible lateral tilt angles during vehicle operation, such as combinations of -5° and 5° lateral tilts. These simulations not only cover common road conditions but also consider hydraulic system operation under extreme conditions. The test data obtained on the test bench simulating different vehicle postures will provide strong support for subsequent optimization designs.

[0049] After adjusting the test bench to the target tilt angle, such as 30% uphill, -30% downhill, or -5°~5° left (right) tilt, let it stand still for a set time, and repeat steps S4 to S6 to obtain test data simulating different postures of the whole vehicle, thereby improving the comprehensiveness and reliability of the oil circuit design scheme verification.

[0050] In step S8 above, the boundary conditions, structural parameters, and measurement results of each experiment are automatically written into a unified database. This database supports continuous expansion and efficient retrieval, becoming a shared knowledge asset for enterprise-level hydraulic circuit design. When developing motors with different power ratings or layouts, engineers can quickly retrieve data and information under similar operating conditions using dimensionless parameters, directly accessing key parameters such as calibration coefficients, thereby significantly reducing the number of initial simulation-experiment iterations and improving design efficiency. Furthermore, the database supports data visualization and analysis functions, helping engineers more intuitively understand the relationships and trends between data, providing strong support for design optimization.

[0051] In this embodiment of the invention, a transparent shell is used instead of a traditional metal shell to ensure a visual observation channel inside the motor, and the shell material meets the stability requirements of a high-temperature oil environment. Fluorescent tracer cooling oil is used, combined with ultraviolet light to excite fluorescence, improving the observability of the oil jet. Three high-speed cameras with a frame rate of 2000fps and a resolution of 1920×1080 are deployed, respectively aimed at the stator winding ends and the stator-rotor air gap, to capture the dynamics of the oil jet from multiple angles. Through image 3D reconstruction technology, the 2D shooting results are converted into a 3D oil jet trajectory, accurately presenting the spray coverage. Furthermore, the imaging system and data acquisition are triggered synchronously to ensure timely observation.

[0052] In this embodiment of the invention, boundary conditions, structural parameters, measurement results, and other data from each experiment can be automatically stored in a database with a unified structure, supporting continuous expansion and efficient retrieval. After the experiment, key parameters such as drag coefficient and flow coefficient are extracted using backfitting technology to generate standardized calibration files, which can be directly used for CAE model updates. The database supports rapid retrieval based on dimensionless parameters, allowing engineers to reuse calibration parameters under similar operating conditions to improve model confidence; it also has data visualization and analysis functions to assist in parameter optimization.

[0053] In this embodiment of the invention, an orthogonal operating condition matrix design is used during the experiment to comprehensively cover key influencing factors within a limited number of tests, reducing redundant testing. The entire experimental process is automatically driven by test software scripts, including operations such as heating, flow stabilization, sampling, imaging, and data archiving, reducing manual intervention and improving process efficiency.

[0054] Secondly, embodiments of the present invention also provide a test device for the above-mentioned verification method of oil circuit and spray design of oil-cooled motor for new energy vehicles, including a test bench, a camera, a light source and an oil-cooled motor under test. The oil-cooled motor under test is set on the test bench, the camera is respectively arranged on the front side and the left and right sides of the oil-cooled motor under test, the light source and the camera are arranged in the same position, and the oil-cooled motor under test includes a transparent shell, which is made of thermoplastic plastic.

[0055] The present invention has been described above with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A method for verifying the design of oil circuit and spray system in an oil-cooled motor for new energy vehicles, characterized in that, Including the following steps: S1. Install the oil-cooled motor under test on the test bench and establish a connection between the oil-cooled motor under test and the external oil supply equipment; S2. Construct an external circulation oil supply circuit. A flow meter and a first pressure sensor are installed in the external circulation oil supply circuit. The oil outlet of the oil-cooled motor under test is connected to the flow meter, the oil outlet of the flow meter is connected to the first pressure sensor, and the oil outlet of the first pressure sensor is connected to the return port of the external oil supply equipment. S3. Install a second pressure sensor and a flow sensor in the oil-cooled motor under test; S4. Set up cameras in multiple field-of-view directions of the oil-cooled motor under test, and arrange a light source to excite the fluorescent tracer on the side of the camera. Inject fluorescent tracer cooling oil into the external circulation oil supply circuit, collect images of the fluorescent tracer in the fluorescent tracer cooling oil through the camera, and obtain the three-dimensional oil beam trajectory based on the images. S5. Construct a test condition matrix based on oil temperature, speed, nozzle specifications and injection angle, and perform heating, flow stabilization, sampling and imaging operations for each condition; S6. Compare the collected pressure, flow rate, and imaging data with the simulation data. Based on the comparison results, obtain the resistance and flow rate parameters of the oil circuit model, generate a calibration file, and update the simulation model. S7. Simulate the oil circuit operation under different vehicle postures by adjusting the tilt angle of the test bench, and record the corresponding test data.

2. The method according to claim 1, characterized in that, The light source is arranged at a predetermined angle to the optical axis of the camera to reduce interference from reflected light; the frame rate of the camera is not less than 1000fps and the resolution is not less than 1280×720.

3. The method according to claim 1, characterized in that, In step S6, a deviation distribution map is generated, and parameter backfitting is performed based on the deviation distribution map.

4. The method according to any one of claims 1 to 3, characterized in that, The fluorescent tracer cooling oil is a mixture of base oil and fluorescent agent. The fluorescent agent produces visible fluorescence when excited at a preset wavelength, and the mass fraction of the fluorescent agent is 0.1% to 1%.

5. The method according to claim 4, characterized in that, The base oil is a polyalphaolefin lubricating oil with a kinematic viscosity of 10-30 cSt at 40°C and a flash point of not less than 180°C. In preparing the fluorescent tracer cooling oil, after adding the fluorescent agent to the base oil, the fluorescent agent is uniformly dispersed by stirring with a magnetic stirrer for a predetermined time.

6. The method according to any one of claims 1 to 3, characterized in that, The transparent shell is made of thermoplastic.

7. The method according to any one of claims 1 to 3, characterized in that, The oil cooling assembly of the tested oil-cooled motor includes an oil injection ring and a nozzle disposed on the oil injection ring. The nozzle and the oil injection ring are connected by a flexible snap or a quick-connect interface.

8. The method according to any one of claims 1 to 3, characterized in that, In step S4, three cameras are set up and arranged on the front and left and right sides of the oil-cooled motor under test, respectively. The camera arranged on the front side is aimed at the end of the stator winding of the oil-cooled motor under test, and the cameras arranged on the left and right sides are aimed at the air gap between the stator and rotor.

9. A test apparatus for verifying the oil circuit and spray design of an oil-cooled motor for new energy vehicles as described in any one of claims 1 to 8, characterized in that, The test includes a test bench, a camera, a light source, and an oil-cooled motor under test. The oil-cooled motor under test is mounted on the test bench. The camera is positioned on the front and left and right sides of the oil-cooled motor under test, respectively. The light source and the camera are positioned in the same location. The oil-cooled motor under test includes a transparent housing made of thermoplastic plastic.

10. The testing equipment according to claim 9, characterized in that, The distance between the camera and the oil-cooled motor under test is 300mm, and the aperture is set to F2.0.

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