Hub bearing sealing performance detection device and method

Abstract

The invention provides a hub bearing sealing performance detection device and method, and belongs to the technical field of bearing detection.The hub bearing sealing performance detection device comprises an experiment box, a placement cavity and a detection cavity are formed in the experiment box through a partition plate, the detection box is arranged at the bottom of the detection cavity and contains anti-rust cooling liquid, and a cooling mechanism is installed in the detection box; a thermal imaging module for acquiring an original thermal imaging view is arranged on one side of the detection box; the detection assembly is used for simulating the working condition of the hub bearing and injecting high-temperature liquid lubricating oil into the hub bearing at the same time, the transfer assembly conveys the hub bearing to a part replacement position in the placement cavity or a detection position in the detection cavity, and the locking assembly is used for connecting the hub bearing at the detection position with the detection assembly; the control module is used for controlling the operation of the detection device; the leaked high-temperature lubricating oil forms a remarkable temperature difference in the low-temperature anti-rust cooling liquid and cooperates with the thermal imaging module to capture a heat source reaction, so that the leakage position can be determined, and the problem that a traditional sealing detection device is inaccurate in leakage position positioning is solved.

Description

Technical Field

[0001] This invention belongs to the field of bearing testing technology, and more specifically, relates to a device and method for testing the sealing performance of wheel hub bearings. Background Technology

[0002] In the automotive industry, wheel bearings are components that support the wheels and bear the vehicle load. If the seal is not good, external dust, moisture and other impurities can easily enter the bearing, leading to grease loss, accelerated bearing wear, and in turn causing abnormal noise and vibration. Therefore, it is necessary to conduct sealing tests on wheel bearings to ensure product quality.

[0003] Existing methods for testing the sealing performance of wheel hub bearings mainly involve manual visual inspection, immersion, and air pressure testing. Visual inspection relies on the operator's experience, judging sealing performance by observing the surface of the bearing seals for defects such as cracks and deformation. This method is not only inefficient but also difficult to detect minute gaps or internal sealing defects. The immersion method involves immersing the wheel hub bearing in water and applying air pressure, observing the formation of bubbles to determine the leak point, but requires drying the bearing afterward. Air pressure testing typically measures changes in internal air pressure to determine sealing performance, but it cannot pinpoint the exact leak location. Therefore, there is an urgent need for a wheel hub bearing sealing performance testing device with high positioning accuracy to solve these problems. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a wheel hub bearing sealing performance testing device and method, thereby solving the technical problem that traditional sealing performance testing devices are not very accurate in locating leakage points in the prior art.

[0005] The purpose and effectiveness of the wheel hub bearing sealing performance testing device and method of the present invention are achieved by the following specific technical means: A wheel hub bearing sealing performance testing device, comprising: The experimental chamber has a placement chamber and a testing chamber formed by a partition plate. The placement chamber and the testing chamber are connected by a through groove on the partition plate. The test chamber is located at the bottom of the test chamber and contains rust-preventive coolant. A cooling mechanism is installed inside the test chamber to cool the rust-preventive coolant. A temperature sensor is installed inside the test chamber to acquire the reference temperature data of the coolant. A thermal imaging module is installed on one side of the test chamber to acquire the original thermal imaging view. The detection component is used to simulate the working conditions of the wheel hub bearing, while injecting liquid lubricating oil into the wheel hub bearing and obtaining the rate of change of injection pressure through a pressure sensor. The transfer assembly is installed at the bottom inside the inspection box and passes through the through slot at the top and is located in the placement cavity. The transfer assembly is used to transport the wheel hub bearing to be inspected to the replacement position in the placement cavity or the inspection position in the inspection cavity. When the wheel hub bearing is located in the inspection position, its rotation axis coincides with the rotation axis of the inspection assembly. The thermal imaging module is located at one end of the rotation axis of the inspection assembly. Locking assembly, used to lock the hub bearing of the detection position to the detection assembly; The control module is installed on the switchable door panel on one side of the experimental chamber. The control module is used to control the operation of the testing device.

[0006] According to a preferred embodiment, the detection assembly includes a rotating shaft and a rotating motor for simulating the working conditions of a wheel hub bearing. A first mounting base is provided inside the detection box. Two sets of first slide rails are provided on the top of the first mounting base. Two sets of first waterproof electric sliders are respectively provided on the two sets of first slide rails. The tops of the two sets of first waterproof electric sliders are connected to a first movable frame. A waterproof box is provided on one side of the first movable frame. A rotating motor is provided inside the waterproof box. The rotating motor is used to drive the rotating shaft to rotate around its own axis. A through hole is provided on one side of the waterproof box, through which a rotating shaft is inserted. One end of the rotating shaft is connected to the main shaft of the rotating motor by two sets of meshing gears. A connecting shaft section for connecting to the hub bearing is provided on the rotating shaft, and a sealed bearing is provided in the through hole corresponding to the rotating shaft.

[0007] According to a preferred embodiment, the detection assembly further includes an oil injection channel for injecting liquid lubricating oil into the wheel hub bearing. The rotating shaft and connecting shaft section have oil injection channels corresponding to the wheel hub bearing. The position of the sealing structure on the wheel hub bearing corresponds to the oil outlet end of the oil injection channel. A heating chamber is installed inside the waterproof box, containing a heating pipe and a heat pipe heater. The heat pipe heater surrounds the heating pipe and heats the lubricating oil it delivers. A pressure sensor is installed at the bottom of the heating pipe. One end of the heating pipe is connected to the oil inlet end of the oil injection channel via a rotary joint. An oil storage tank is installed inside the waterproof box, with an oil pump installed on top of the oil storage tank. The oil pump connects the other end of the heating pipe to the oil storage tank via a pipeline.

[0008] According to a preferred embodiment, the locking assembly includes a locking bushing for locking the hub bearing onto the connecting shaft section. A second mounting base is provided inside the detection box, and a lifting column is provided above the second mounting base. A waterproof locking motor is provided on one side of the lifting column. The waterproof locking motor is used to install the locking bushing on one side of the connecting shaft section. A rotating plate is connected to the shaft end of the waterproof locking motor. A gripping structure and a waterproof electric telescopic rod are provided on one side of the rotating plate. The waterproof electric telescopic rod is used to drive the gripping structure to grip the locking bushing. The second mounting base has two sets of third slide rails on its top, each set of third slide rails is equipped with a third waterproof electric slider, and the top of each set of third waterproof electric sliders is connected to the lifting platform. The top of the lifting platform has a lifting groove, and the lifting column slides through the lifting groove. The lifting column is used to move the gripping structure and the waterproof locking motor to the detection position or avoidance position in the detection chamber. When the gripping structure and the waterproof locking motor are in the detection position, their rotation axis coincides with the rotation axis of the wheel hub bearing and the rotation axis of the detection component located in the detection position. A rack is provided on one side of the lifting column, and a waterproof lifting motor is provided on one side of the lifting platform. A gear is provided on the main shaft of the waterproof lifting motor that meshes with the rack.

[0009] According to a preferred embodiment, the transfer assembly includes a fixing plate for placing the hub bearing. The bottom of the transfer bracket is installed inside the testing box, and the top passes through the through slot and is located in the placement cavity. Two sets of second slide rails are provided on one side of the transfer bracket. Two sets of second waterproof electric sliders are provided on one side of each of the two sets of second slide rails. One side of each of the four sets of second waterproof electric sliders is connected to the lifting frame. A fixing plate is rotatably provided on one side of the lifting frame. Multiple sets of fixing holes are opened on one side of the fixing plate. The hub bearing is connected to the multiple sets of fixing holes through multiple sets of fixing screws.

[0010] A positioning method for a wheel hub bearing sealing performance testing device includes the following steps: The injection pressure change rate is obtained based on the pressure sensor, and a shutdown protocol is triggered and a leakage trigger flag is output based on the injection pressure change rate. The thermal imaging module is activated based on the leakage trigger flag to obtain several frames of original thermal imaging views. A pre-stored temperature-grayscale lookup table is obtained, and the several frames of original thermal imaging views are converted into several frames of temperature field views according to the temperature-grayscale lookup table. The temperature field views are represented by temperature points. The reference temperature data of the coolant is obtained based on the temperature sensor, and the peak temperature rise view is obtained based on several frames of temperature field view and the reference temperature data of the coolant. A thermal gradient vector field is constructed based on the peak temperature rise view, and a divergence distribution map is generated based on the thermal gradient vector field and the peak temperature rise view. Multiple temperature decay paths are obtained based on the divergence distribution map, and the leakage source confidence of multiple temperature decay paths is verified to obtain the coordinates of the leakage point. Based on the coordinates of the leakage point and the projection view of the 3D model of the wheel hub bearing, the leakage location parameters of the wheel hub bearing are obtained.

[0011] According to a preferred embodiment, the step of converting several frames of original thermal imaging views into several frames of temperature field views based on a temperature-grayscale lookup table includes: Pixels are extracted from each frame of the original thermal imaging view based on several frames of original thermal imaging views. A pre-calibrated temperature-grayscale lookup table is loaded to perform a lookup transformation on each pixel, and each pixel is converted into a temperature point according to the temperature-grayscale lookup table, resulting in several frames of temperature field views.

[0012] According to a preferred embodiment, the step of obtaining the peak temperature rise view based on several frames of temperature field views and coolant reference temperature data includes: Extract real-time temperature data for each temperature point in each frame of the temperature field view, and obtain several temperature difference data by subtracting several real-time temperature data from the coolant reference temperature data. Each temperature point in each frame of the temperature field view is converted into a temperature difference point based on the corresponding temperature difference data, generating several frames of relative temperature rise field view; Several frames of temperature rise field view are overlaid with several frames of original thermal imaging view. The highest temperature difference data of several temperature difference points at each pixel position are recorded to obtain the highest temperature difference point. Several highest temperature difference points are then used to construct a peak temperature rise view.

[0013] According to a preferred embodiment, the step of constructing a thermal gradient vector field based on a peak temperature rise view, and generating a divergence distribution map based on the thermal gradient vector field and the peak temperature rise view, includes: Extract each maximum temperature difference point in the peak temperature rise view, obtain the horizontal temperature change rate based on the horizontal temperature difference between each maximum temperature difference point and the adjacent maximum temperature difference point, and obtain the vertical temperature change rate based on the vertical temperature difference between each maximum temperature difference point and the adjacent maximum temperature difference point. For each highest temperature difference point, a vector arrow is generated based on the corresponding horizontal and vertical temperature change rates. The vector arrow points in the direction of the fastest temperature increase. Several vector arrows are combined into a vector arrow diagram, which is the thermal gradient vector field. The thermal gradient vector field is overlaid with the peak temperature rise view to obtain the divergence value of each maximum temperature difference point. A divergence distribution map is generated based on the peak temperature rise view and the divergence value of each corresponding maximum temperature difference point. The divergence value represents the direction of the vector arrows; The higher the divergence value, the fewer points the vector arrow points to; The lower the divergence value, the more the vector arrow points.

[0014] According to a preferred embodiment, the method further includes: In the divergence distribution map, all the highest temperature difference points with divergence values ​​below the threshold are selected, and these highest temperature difference points are constructed into a candidate point set. Starting from each candidate point, the temperature difference between adjacent highest temperature difference points is lower than the tracking threshold and is tracked upwards until the temperature drops to 10% of the highest temperature or reaches the surface of the coolant, generating multiple temperature decay paths. Leakage source confidence verification is performed for multiple temperature decay paths. Multiple highest temperature difference points are randomly selected on the temperature decay path, and the average offset angle of the temperature decay path corresponding to the multiple highest temperature difference points is calculated to verify the vertical characteristics. If the verification is successful, the candidate point is selected as the leakage point coordinate; otherwise, the candidate point is judged as an interference signal.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The actual rotational conditions of a wheel hub bearing are simulated by rotating a shaft and a rotating motor. Simultaneously, heated liquid lubricating oil is injected into the bearing through an oil injection channel. This creates a significant temperature difference in the low-temperature anti-rust coolant environment caused by the leaking lubricating oil. A thermal imaging module on one side of the detection chamber directly captures the heat source reaction generated by the leak, obtaining a raw thermal image. This raw thermal image is then converted into a temperature field view. Combined with the coolant reference temperature, a peak temperature rise view is extracted, focusing on the region of highest temperature difference. Irrelevant temperature fluctuations in the low-temperature anti-rust coolant environment are filtered out, concentrating the analysis on the possible leak area and reducing interference from non-leakage factors in localization. A thermal gradient is constructed... By generating a vector field and a divergence distribution map, and analyzing the rate of temperature change and vector direction, the core region with the fastest temperature rise is identified, eliminating temperature diffusion interference caused by coolant flow. The specific location of the leak source is pinpointed based on the temperature change pattern, improving the accuracy of the location. Finally, the coordinates of the leak point are combined with the projection view of the 3D model of the wheel hub bearing to directly output the specific parameters of the leak location relative to the bearing structure. This allows the detection results to correspond with the bearing's sealing devices, joints, and other parts, providing clear location guidance for subsequent analysis of the cause of seal failure and repair. This helps to pinpoint the leak location and solves the problem of inaccurate leak location positioning in traditional sealing detection devices.

[0016] 2. With the transfer assembly in place, the inspector can mount the wheel bearing to be inspected on the fixed plate located at the replacement position. Then, the second waterproof electric slider moves on the second slide rail to transport the wheel bearing to the inspection position, ensuring that the axis of the wheel bearing coincides with the axis of the rotating shaft in the inspection assembly. This achieves smooth transfer of the wheel bearing from the replacement position to the inspection position. Since the inspection position is in the inspection box, which contains low-temperature rust-preventive coolant, the transfer assembly avoids the inspector operating in the low-temperature rust-preventive coolant, thus improving convenience.

[0017] 3. By setting the locking component, when the wheel hub bearing is in the detection position, the first waterproof electric slider moves on the first slide rail, so that one end of the rotating shaft passes through the inner ring of the wheel hub bearing until the wheel hub bearing is sleeved on the outer side of the connecting shaft section on the rotating shaft. The waterproof lifting motor is started, and the gear meshes with the rack on the lifting column, driving the lifting column to move up and down along the lifting slide groove on the top of the lifting platform. The height of the waterproof locking motor is adjusted so that the axis of the locking sleeve coincides with the axis of the rotating shaft. The third waterproof electric slider moves on the third slide rail, and the waterproof locking motor is started. Its main shaft drives the rotating plate, slide plate and multiple sets of gripping plates to rotate, installing the locking sleeve on one end of the rotating shaft, axially locking the wheel hub bearing on the connecting shaft section, completing the installation and fixing. This reduces the distortion of detection data caused by bearing displacement, reduces the detection error caused by improper installation, and can be adapted to wheel hub bearings of different specifications through structural adjustment. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the assembled structure of the present invention; Figure 2 This is a schematic diagram of the structure of the present invention after it has been unfolded; Figure 3 This is a schematic diagram of the assembled detection component in this invention; Figure 4 This is a schematic diagram of the disassembled detection component in this invention; Figure 5 This is a schematic diagram of the assembled transfer component in this invention; Figure 6 yes Figure 5 A schematic diagram of the disassembled structure; Figure 7 This is a schematic diagram of the structure of the locking component after assembly in this invention; Figure 8 yes Figure 7 A schematic diagram of the disassembled structure; Figure 9 This is a flowchart of the positioning method of a wheel hub bearing sealing performance testing device according to the present invention; Figure 10 This is a flowchart of the steps for obtaining a peak temperature rise view in the positioning method of a wheel hub bearing sealing performance testing device of the present invention; Figure 11 This is a flowchart of the steps for generating a divergence distribution map in the positioning method of a wheel hub bearing sealing performance testing device of the present invention.

[0019] In the diagram, the correspondence between component names and drawing numbers is as follows: 101. Experimental chamber; 102. Divider plate; 103. Through slot; 104. Detection box; 105. Temperature sensor; 106. Thermal imaging module; 107. Hub bearing; 108. Control module; 109. Openable door panel; 201. Pressure sensor; 202. Rotating shaft; 203. Rotating motor; 204. First mounting base; 205. First slide rail; 206. First waterproof electric slider; 207. First moving frame; 208. Waterproof box; 210. Connecting shaft section; 211. Sealed bearing; 212. Oil injection channel; 213. Heating box; 214. Heating tube; 215. Heat pipe heater; 217. Oil storage tank; 218. Oil pump; 301. Locking bushing; 302. Second mounting base 303. Lifting column; 304. Waterproof locking motor; 305. Rotating plate; 306. Connecting rod; 307. Slide plate; 308. First sliding groove; 309. Gripping plate; 310. Sliding rod; 311. Waterproof electric telescopic rod; 312. Driving block; 313. Second sliding groove; 314. First rotating seat; 315. Second rotating seat; 316. Connecting rod; 317. Third slide rail; 318. Third waterproof electric slider; 319. Lifting platform; 320. Lifting slide groove; 322. Rack; 323. Waterproof lifting motor; 324. Slide cylinder; 401. Fixing plate; 402. Transfer bracket; 403. Second slide rail; 404. Second waterproof electric slider; 405. Lifting frame; 406. Fixing hole. Detailed Implementation

[0020] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the technical solutions of the present invention, but should not be used to limit the scope of protection of the present invention.

[0021] Example:

[0022] As attached Figures 1 to 8 As shown: This invention provides a wheel hub bearing sealing performance testing device, comprising: The test chamber 101 has a placement chamber and a testing chamber formed by a partition plate 102. The placement chamber is used for the testing personnel to install or remove the wheel hub bearing 107 to be tested, and the testing chamber is used for sealing testing. The placement chamber and the testing chamber are connected by a passage groove 103 on the partition plate 102, which provides a channel for the transfer assembly to transport the wheel hub bearing 107. The testing chamber 104 is located at the bottom of the testing chamber and contains rust-preventive coolant. The testing chamber 104 is equipped with a cooling mechanism that continuously cools the rust-preventive coolant to maintain a stable temperature, so that the low-temperature rust-preventive coolant surrounds the wheel hub bearing 107 at the testing position, reducing the interference of the external ambient temperature on the testing. The testing chamber 104 is equipped with a temperature sensor 105 for acquiring the reference temperature data of the coolant, which serves as a reference for subsequent temperature comparison. A thermal imaging module 106 for acquiring the original thermal imaging view is set on one side of the testing chamber 104, and the thermal imaging module 106 faces the wheel hub bearing 107 at the testing position. The detection component is used to simulate the working conditions of the wheel hub bearing 107. Simultaneously, liquid lubricating oil is injected into the wheel hub bearing 107 and the injection pressure change rate is obtained through the pressure sensor 201. The rotating shaft 202 of the detection component rotates under the drive of the rotating motor 203, which drives the wheel hub bearing 107 sleeved on it to rotate synchronously, simulating the rotation conditions when the vehicle is driving. The oil injection channel continuously injects heated liquid lubricating oil into the wheel hub bearing 107. The pressure sensor 201 monitors the pressure change during the oil injection process. When there is a leak, the pressure change rate will be abnormal. The bottom of the transfer assembly is installed inside the inspection box 104, and the top passes through the through slot 103 and is located in the placement cavity. The fixing plate 401 of the transfer assembly is used to place the wheel hub bearing 107 to be inspected. The wheel hub bearing 107 is moved between the replacement position in the placement cavity and the inspection position in the inspection cavity by the movement of the second waterproof electric slider 404 on the second slide rail 403. When the wheel hub bearing 107 is in the inspection position, the rotation axis of the wheel hub bearing 107 coincides with the rotation axis of the inspection assembly, ensuring that the two rotate coaxially during inspection. The locking assembly is used to lock the hub bearing 107 of the detection position to the detection assembly. By moving the third waterproof electric slider 318 and driving the waterproof locking motor 304, the locking sleeve 301 is installed at the end of the rotating shaft 202, so that the hub bearing 107 is securely sleeved on the outside of the connecting shaft section 210 of the rotating shaft 202, and displacement is prevented during the detection process.

[0023] Specifically, during testing, the hub bearing 107 is first installed on the fixed plate of the transfer assembly, which then transports it to the testing position via the passageway 103. The locking assembly then fixes it to the testing assembly. Subsequently, the testing assembly is activated, and the rotating shaft 202 rotates under the drive of the rotating motor 203, simulating actual rotation conditions. At the same time, heated liquid lubricating oil is injected into the hub bearing 107 through the oil injection channel, and the pressure sensor 201 monitors the rate of change of the injection pressure in real time. If there is a sealing defect in the hub bearing 107, the heated liquid lubricating oil will leak from the gap into the anti-rust coolant in the testing box 104. Because the temperature of the leaked lubricating oil is higher than that of the coolant, a local high-temperature area will be formed around the leak point. The thermal imaging module 106 captures this high-temperature area by taking an original thermal image. Combined with the coolant reference temperature data obtained by the temperature sensor 105, the temperature difference between the high-temperature area and the surrounding coolant can be clearly identified, thereby locating the leak location.

[0024] For example, during the testing of the wheel hub bearing 107, the rotating shaft 202 continues to rotate, and heated liquid lubricating oil is injected into the oil injection channel 212. The pressure sensor 201 detects an abnormal change rate in the injection pressure. At this time, in the original thermal imaging view captured by the thermal imaging module 106, a significant high-temperature area appears at the position corresponding to the sealing lip of the wheel hub bearing 107. By comparing the temperature of this area with the reference temperature of the coolant obtained by the temperature sensor 105, it is confirmed that the high-temperature area is caused by leaking lubricating oil, thus determining that the leak location is at the sealing lip. This solves the problem that traditional sealing detection devices are not very accurate in locating the leak location.

[0025] The control module 108 is installed on the switchable door panel 109 on one side of the test chamber 101. The tester can input the test parameters and issue the start command through the operation interface on the door panel. After receiving the command, the control module 108 coordinates the operation of each component to realize the control of the sealing test of the wheel hub bearing 107. Specifically, when the control module 108 tests the wheel hub bearing 107, it first receives the start command and preset test parameters input by the testing personnel, and then activates the coordinated operation of each component in sequence: the second waterproof electric slider 404 of the control transfer component moves vertically on the second slide rail 403, driving the top lifting frame 405 and the wheel hub bearing 107 fixed on the fixed plate 401 to descend. The fixed plate 401 is connected to the wheel hub bearing 107 by fixing screws to ensure that it will not shake during the transfer process. When the wheel hub bearing 107 reaches the level with the test position... When the height is reached, the second waterproof electric slider 404 stops moving, transporting the hub bearing 107 from the replacement position in the placement cavity through the through groove 103 on the partition plate 102 to the detection position in the detection cavity; after the hub bearing 107 reaches the detection position, the control module 108 sends a signal to the detection component, causing the first waterproof electric slider 206 to move on the first slide rail 205 toward the hub bearing 107, driving the rotating shaft 202 to approach horizontally until one end of the rotating shaft 202 passes through the inner ring of the hub bearing 107, so that the hub bearing 107 is fitted onto the rotating shaft 202. The outer side of the connecting shaft section 210 is tightly fitted with the inner ring of the hub bearing 107 to ensure synchronous rotation. Next, the third waterproof electric slider 318 of the locking assembly moves on the third slide rail 317 to adjust the horizontal position of the locking assembly. Simultaneously, the waterproof lifting motor 323 is activated, driving the lifting column 303 to move up and down along the lifting groove 320 of the lifting platform 319 via gear meshing with the rack 322 on the lifting column 303. This causes the axis of the locking sleeve 301 to coincide with the axis of the rotating shaft 202 and the hub bearing 107. Then, the waterproof locking motor 304 is started, which drives the rotating plate 305 and the slide plate 307 to rotate, and screws the locking bushing 301 into the end of the rotating shaft 202, axially locking the hub bearing 107 onto the connecting shaft section 210. After locking is completed, the control module 108 drives the waterproof electric telescopic rod 311 to extend and retract, which drives the gripping plate 309 to open along the first sliding groove 308 to release the locking bushing 301. Then, through the cooperation of the third waterproof electric slider 318 and the waterproof lifting motor 323, the locking component is moved to the avoidance position on the side of the detection position to avoid interfering with subsequent detection actions.

[0026] Furthermore, after locking is completed, the control module 108 activates the detection component: it controls the heat pipe heater 215 in the heating box 213 to be energized and heated, heating the liquid lubricating oil flowing in the heating pipe 214, so that the temperature of the lubricating oil is higher than the temperature of the anti-rust coolant in the detection box 104. At the same time, the oil pump 218 is started to pump the lubricating oil in the oil storage tank 217 into the heating pipe 214 for heating, and then delivers it through the rotary joint to the oil injection channel 212 on the rotating shaft 202 and the connecting shaft section 210, continuously injecting it into the wheel hub bearing 107. The pressure sensor 201 monitors the injection in real time. The pressure change within the oil passage 212 is calculated and the injection pressure change rate is transmitted to the control module 108. The rotating motor 203 is started synchronously, and the rotating shaft 202 is driven to rotate around its own axis through two sets of meshing gears. This, in turn, drives the wheel hub bearing 107 sleeved on the connecting shaft section 210 to rotate synchronously, simulating the rotation condition when the vehicle is in motion. During this process, the control module 108 receives the injection pressure change rate from the pressure sensor 201 in real time, and continuously monitors the coolant reference temperature data collected by the temperature sensor 105, providing a reference for subsequent thermal imaging analysis.

[0027] It should be noted that when the rate of change of injection pressure exceeds the preset threshold, the control module 108 triggers the shutdown protocol and immediately performs a shutdown operation: shutting down the rotating motor 203 to stop the rotation of the rotating shaft 202, preventing continuous rotation from expanding the leakage range; at the same time, the thermal imaging module 106 is started to continuously shoot for 5 seconds at its own set shooting frequency to obtain several frames of original thermal imaging views covering the wheel hub bearing 107 and the surrounding area; subsequently, the control module 108 calls the pre-stored temperature-grayscale lookup table to convert the original thermal imaging view into a temperature field view, and combines the coolant reference temperature data obtained by the temperature sensor 105 to extract the peak temperature rise area higher than the reference temperature, and then verifies the temperature decay path by constructing a thermal gradient vector field and divergence distribution map, finally obtaining the coordinates of the leakage point, and comparing the coordinates with the projection view of the three-dimensional model of the wheel hub bearing to output the specific leakage location parameters.

[0028] Please see as follows Figure 3 and Figure 4As shown, the detection assembly includes a rotating shaft 202 and a rotating motor 203 for simulating the working conditions of the wheel hub bearing 107. A first mounting base 204 is provided inside the detection box 104, fixed to the bottom of the detection box 104 to provide support for the detection assembly. Two sets of first slide rails 205 are arranged parallel to each other on the top of the first slide rails 205, extending towards or away from the detection position. When the detection assembly approaches the detection position, one end of the rotating shaft 202 can pass through the wheel hub bearing 107 located at the detection position. Two sets of first waterproof electric sliders 206 are respectively installed on the first slide rail 205. The first waterproof electric sliders 206 can slide along the first slide rail 205. The tops of the two sets of first waterproof electric sliders 206 are fixedly connected to the first movable frame 207. The sliding of the first waterproof electric sliders 206 can drive the first movable frame 207 to move synchronously. A waterproof box 208 is installed on one side of the first movable frame 207. The waterproof box 208 adopts a sealed structure to isolate the anti-rust coolant in the test box 104 and protect the internal components. The waterproof box 208 is fixed with... A rotating motor 203 outputs power to drive a rotating shaft 202 to rotate around its own axis. A through hole is provided on the side of the waterproof housing 208 facing the detection position, through which the rotating shaft 202 passes. One end of the rotating shaft 202 is located inside the waterproof housing 208, and the other end extends out of the waterproof housing 208. The end of the rotating shaft 202 located inside the waterproof housing 208 is connected to the main shaft of the rotating motor 203 via two sets of meshing gears. Gear transmission transmits the power of the rotating motor 203 to the rotating shaft 202, driving the rotating shaft 202... 02. The rotating shaft 202 extends out of the waterproof box 208 and is provided with a connecting shaft section 210 for connecting with the hub bearing 107. The outer diameter of the connecting shaft section 210 is adapted to the inner diameter of the inner ring of the hub bearing 107 for the hub bearing 107 to be fitted. A sealing bearing 211 is provided in the through hole corresponding to the rotating shaft 202. The inner ring of the sealing bearing 211 is tightly fitted with the outer circumferential surface of the rotating shaft 202, and the outer ring is fixed to the inner wall of the through hole. This ensures that the rotating shaft 202 rotates smoothly and prevents the anti-rust coolant from seeping into the interior of the waterproof box 208 through the through hole.

[0029] Specifically, during use, after the transfer assembly transports the hub bearing 107 to the detection position and adjusts it to be coaxial with the rotating shaft 202, the control module 108 controls the first waterproof electric slider 206 to move along the first slide rail 205 towards the detection position, causing the first moving frame 207, the waterproof box 208, and the rotating shaft 202 to synchronously approach the hub bearing 107, so that one end of the rotating shaft 202 extending out of the waterproof box 208 passes through the inner ring of the hub bearing 107 until the hub bearing 107 is fitted onto the outside of the connecting shaft section 210. At this time, the outer circumference of the connecting shaft section 210 is flush with the wheel bearing 107. The inner rings of the hub bearing 107 are fitted together, completing the docking. Subsequently, the rotating motor 203 is started, and its main shaft drives the gear meshing with it to rotate. Through gear transmission, the rotating shaft 202 rotates around its own axis, thereby driving the hub bearing 107 sleeved on the connecting shaft section 210 to rotate synchronously, thus simulating the rotation condition of the hub bearing 107 when the vehicle is in motion. During this process, the sealing structure of the waterproof box 208 cooperates with the sealing bearing 211 to prevent the anti-rust coolant in the test box 104 from entering the waterproof box 208, thus preventing the rotating motor 203 from being damaged by moisture.

[0030] For example, when the hub bearing 107 is being tested, the first waterproof electric slider 206 moves along the first slide rail 205, so that the rotating shaft 202 is precisely inserted into the inner ring of the hub bearing 107 and fitted onto the connecting shaft section 210. After the rotating motor 203 is started, it drives the rotating shaft 202 to rotate at a set speed through gear transmission. The hub bearing 107 rotates synchronously with the rotating shaft 202. During this period, the waterproof box 208 and the sealed bearing 211 effectively isolate the anti-rust coolant, ensuring the stable operation of the rotating motor 203 and providing reliable power for simulating actual working conditions.

[0031] Please see as follows Figure 4As shown, the testing assembly also includes an oil injection channel 212 for injecting liquid lubricating oil into the hub bearing 107. The rotating shaft 202 and the connecting shaft section 210 are connected by the oil injection channel 212 along the axial direction. The oil outlet of the oil injection channel 212 is located on the outer circumferential surface of the connecting shaft section 210, and its position corresponds to the inner side of the sealing device on the hub bearing 107, allowing the injected liquid lubricating oil to directly act on the sealing device to test the sealing performance. During oil injection, the flow direction of the liquid lubricating oil in the oil injection channel 212 is from the oil inlet end to the oil outlet end. A heating box 213 is fixed inside the waterproof box 208. The heating box 213 has a closed structure and is equipped with heating pipes 214 and heat pipe heaters 215. The heating pipes 214 are arranged in a serpentine pattern to increase the heating area, and the heat pipe heaters 215 surround the heating pipes 214. Heat conduction heats the liquid lubricating oil in the heating tube 214, making its temperature higher than that of the rust-preventive coolant in the detection box 104, creating a significant temperature difference. A pressure sensor 201 is installed at the bottom of the heating tube 214, which is connected to the inside of the heating tube 214 to monitor the oil pressure changes in the heating tube 214 in real time and calculate the injection pressure change rate. One end of the heating tube 214 is connected to the oil inlet of the oil injection channel 212 through a rotary joint. The rotary joint can rotate with the rotating shaft 202 to keep the oil passage unobstructed and avoid pipe entanglement. An oil storage tank 217 is also provided in the waterproof box 208. The oil storage tank 217 is used to store the liquid lubricating oil to be injected. An oil pump 218 is installed on its top. The oil inlet of the oil pump 218 is connected to the bottom of the oil storage tank 217 through a pipe, and the oil outlet is connected to the other end of the heating tube 214 through a pipe, forming a lubricating oil circulation path.

[0032] Specifically, during use, after the hub bearing 107 is fitted onto the connecting shaft section 210 and locked, the control module 108 starts the oil pump 218 to pump the liquid lubricating oil in the oil tank 217 into the heating tube 214. At the same time, the heat pipe heater 215 is energized and heats up, transferring heat to the internal lubricating oil through the surrounding heating tube 214, causing the lubricating oil temperature to rise. The heated lubricating oil flows into the oil injection channel 212 through the rotary joint, and is transported to the oil outlet end along the channel inside the rotating shaft 202 and the connecting shaft section 210, directly injecting into the inner side of the sealing device of the hub bearing 107, forming continuous pressure on the sealing device. During this process, the pressure sensor 201 monitors the oil pressure in the heating tube 214 in real time. When there is a leak in the sealing device of the hub bearing 107, the lubricating oil will flow out from the sealing gap, causing the pressure in the heating tube 214 to fluctuate. The pressure sensor 201 transmits the pressure change signal to the control module 108 to determine whether there is a leak.

[0033] For example, when the wheel hub bearing 107 is being tested, the oil pump 218 pumps the lubricating oil in the oil reservoir 217 into the heating pipe 214. The heat pipe heater 215 works to raise the temperature of the lubricating oil to the set value. The heated lubricating oil is injected into the inside of the bearing sealing device through the oil injection channel 212. If there is a gap in the lip of the sealing device, the lubricating oil will leak from the gap into the anti-rust coolant. At this time, the pressure sensor 201 detects an abnormal change rate in the injection pressure, and the control module 108 triggers the subsequent testing process accordingly.

[0034] Please see as follows Figure 7 and Figure 8 As shown, the locking assembly includes a locking sleeve 301 that locks the hub bearing 107 onto the connecting shaft section 210. A second mounting base 302 is provided inside the detection box 104. A lifting column 303 is positioned above the second mounting base 302. A waterproof locking motor 304 is positioned on one side of the lifting column 303. The waterproof locking motor 304 is used to mount the locking sleeve 301 onto one side of the connecting shaft section 210. A rotating plate 305 is connected to the shaft end of the waterproof locking motor 304. A gripping structure for gripping the locking sleeve 301 is provided on one side of the rotating plate 305. The gripping structure includes a slide plate 307. One side of the rotating plate 305 is connected to the slide plate 307 via multiple sets of connecting rods 306. Multiple sets of radially arranged first sliding grooves 308 are provided on the slide plate 307. One end of each set of gripping plates 309... The locking bushing 301 is gripped by sliding rod 310 and first sliding groove 308. A slide cylinder 324 is provided on one side of slide plate 307 and a waterproof electric telescopic rod 311 is provided on one side of rotating plate 305. One end of the waterproof electric telescopic rod 311 is connected to a driving block 312. Multiple sets of second sliding grooves 313 are opened around the slide cylinder 324 and are evenly distributed around the slide cylinder 324. Multiple sets of first rotating seats 314 are provided around the driving block 312 and slide through multiple sets of second sliding grooves 313 respectively. Two sets of second rotating seats 315 are provided at the bottom of gripping plate 309. The two sets of second rotating seats 315 are connected to two sets of first rotating seats 314 in the second sliding groove 313 respectively through two sets of connecting rods 316. The second mounting base 302 has two sets of third slide rails 317 on its top. Each set of third slide rails 317 is equipped with a third waterproof electric slider 318. The top of each set of third waterproof electric sliders 318 is connected to the lifting platform 319. The top of the lifting platform 319 is provided with a lifting groove 320. The lifting column 303 slides through the lifting groove 320. The lifting column 303 is used to move the locking bushing 301 and the waterproof locking motor 304 to the detection position or the avoidance position in the detection cavity. When the locking bushing 301 and the waterproof locking motor 304 are in the detection position, their rotation axis coincides with the rotation axis of the wheel hub bearing 107 and the rotation axis of the detection component located in the detection position. When the locking bushing 301 and the waterproof locking motor 304 are in the avoidance position, their rotation axis does not coincide with the rotation axis of the wheel hub bearing 107 and the rotation axis of the detection component located in the detection position. A rack 322 is provided on one side of the lifting column 303, and a waterproof lifting motor 323 is provided on one side of the lifting platform 319. A gear is provided on the main shaft of the waterproof lifting motor 323 to mesh with the rack 322.

[0035] Specifically, through the setting of the locking component, when the hub bearing 107 is in the detection position, the first waterproof electric slider 206 moves on the first slide rail 205, causing one end of the rotating shaft 202 to pass through the inner ring of the hub bearing 107 until the hub bearing 107 is sleeved on the outer side of the connecting shaft section 210 on the rotating shaft 202. The waterproof lifting motor 323 is activated, and through gear meshing with the rack 322 on the lifting column 303, the lifting column 303 is driven to move up and down along the lifting slide groove 320 at the top of the lifting platform 319. The height of the waterproof locking motor 304 is adjusted to lock the bushing 30. The axis of 1 coincides with the axis of the rotating shaft 202. The third waterproof electric slider 318 moves on the third slide rail 317, and the waterproof locking motor 304 is started. Its main shaft drives the rotating plate 305, the slide plate 307 and multiple sets of gripping plates 309 to rotate. The locking bushing 301 is installed on one end of the rotating shaft 202, and the hub bearing 107 is axially locked on the connecting shaft section 210, completing the installation and fixing. This reduces the distortion of detection data caused by bearing displacement, reduces the detection error caused by improper installation, and can be adapted to hub bearings 107 of different specifications through structural adjustment.

[0036] Please see as follows Figure 7 and Figure 8As shown, the locking assembly includes a locking sleeve 301 that locks the hub bearing 107 onto the connecting shaft section 210. The inner wall of the locking sleeve 301 is provided with a connecting structure that adapts to the outer periphery of the end of the connecting shaft section 210, and can achieve a threaded connection with the connecting shaft section 210 by rotation. A second mounting base 302 is provided inside the test box 104. The second mounting base 302 is fixed to the bottom of the test box 104 to provide support for the locking assembly. A lifting column 303 is provided above the second mounting base 302. The lifting column 303 can move in the vertical direction. A waterproof locking motor 304 is provided on one side of the lifting column 303. The housing of the waterproof locking motor 304 adopts a sealed design to prevent the ingress of rust-preventive coolant. The locking bushing 301 is used to drive the rotation of the locking bushing 301 and is installed on one side of the connecting shaft section 210. The shaft end of the waterproof locking motor 304 is fixedly connected to the rotating plate 305 through a coupling. The rotating plate 305 rotates synchronously with the main shaft of the waterproof locking motor 304. One side of the rotating plate 305 is connected to the slide plate 307 through multiple sets of connecting rods 306. The multiple sets of connecting rods 306 are evenly distributed along the circumference of the rotating plate 305, so that the slide plate 307 and the rotating plate 305 rotate synchronously. Multiple sets of radially arranged first sliding grooves 308 are opened on the slide plate 307. The multiple sets of first sliding grooves 308 radiate outward from the center of the slide plate 307. One end of each of the multiple gripping plates 309 is connected to the first sliding groove through a sliding rod 310. The groove 308 is slidably connected, and the sliding rod 310 can slide freely within the first sliding groove 308, thereby enabling the gripping plate 309 to move radially along the first sliding groove 308 to grip and release the locking sleeve 301. A slide cylinder 324 is provided on one side of the slide plate 307, and the slide cylinder 324 is coaxially fixed with the slide plate 307. A waterproof electric telescopic rod 311 is provided on one side of the rotating plate 305. The outer shell of the waterproof electric telescopic rod 311 is also sealed. One end of the rod is connected to a driving block 312, which is annularly sleeved on the outer circumference of the slide cylinder 324. Multiple sets of second sliding grooves 313 are opened on the circumference of the slide cylinder 324, and the multiple sets of second sliding grooves 313 are evenly distributed along the circumference of the slide cylinder 324. The cloth, the drive block 312 is provided with multiple sets of first rotating seats 314 around its periphery, and the multiple sets of first rotating seats 314 are respectively slidably inserted into multiple sets of second sliding grooves 313. The first rotating seats 314 can slide in the second sliding grooves 313 and rotate around their own axis. The bottom of the gripping plate 309 is provided with two sets of second rotating seats 315. The two sets of second rotating seats 315 are connected to two sets of first rotating seats 314 in the second sliding grooves 313 through two sets of connecting rods 316. When the waterproof electric telescopic rod 311 extends or retracts, it drives the drive block 312 to move along the axial direction of the slide cylinder 324, and drives the gripping plate 309 to slide in the first sliding groove 308 through the connecting rods 316, so as to realize the opening and closing of the gripping plate 309.

[0037] The second mounting base 302 has two sets of third slide rails 317 on its top. The two sets of third slide rails 317 are arranged parallel to each other in the direction of approaching or moving away from the detection position. Each set of third slide rails 317 is equipped with a third waterproof electric slider 318, which can slide along the third slide rails 317. The tops of the two sets of third waterproof electric sliders 318 are fixedly connected to the lifting platform 319. The sliding of the third waterproof electric sliders 318 can drive the lifting platform 319 to move synchronously. The top of the lifting platform 319 is provided with a lifting groove 320. The bottom of the lifting column 303 is provided with a slider that matches the lifting groove 320. The slider slides through the lifting groove 320, allowing the lifting column 303 to slide up and down along the lifting groove 320. The lifting column 303 is used to move the locking sleeve 301 and the waterproof locking motor 304 to the detection position or avoidance position in the detection cavity. When the 04 is in the detection position, its rotation axis coincides with the rotation axis of the hub bearing 107 and the detection component, ensuring that the locking sleeve 301 can accurately mate with the connecting shaft section 210. When the locking sleeve 301 and the waterproof locking motor 304 are in the clearance position, its rotation axis does not coincide with the rotation axis of the hub bearing 107 and the detection component, avoiding interference with the rotation of the hub bearing 107 during the detection process. A rack 322 is provided on one side of the lifting column 303, and the rack 322 extends along the length of the lifting column 303. A waterproof lifting motor 323 is provided on one side of the lifting platform 319. A gear is provided on the main shaft of the waterproof lifting motor 323, and the gear meshes with the rack 322. When the waterproof lifting motor 323 rotates, the lifting column 303 is driven to move up and down along the lifting slide 320 through the meshing transmission of the gear and the rack 322.

[0038] Specifically, after the lifting column 303 moves up and down along the lifting slide 320 to make the axis of the locking sleeve 301 coincide with the axis of the rotating shaft 202 and the hub bearing 107, the third waterproof electric slider 318 is then activated, moving it along the third slide rail 317 towards the detection position. This causes the lifting platform 319 and the lifting column 303, waterproof locking motor 304, and locking sleeve 301 on the platform to synchronously approach the detection position until the locking sleeve 301 is aligned with the end of the connecting shaft section 210, and the waterproof locking motor 304... The locking bushing 301 is rotated and installed on one end of the rotating shaft 202, thus completing the installation and fixation of the hub bearing 107. Then, the waterproof electric telescopic rod 311 is activated to extend, causing the driving block 312 to move axially along the slide cylinder 324. Through the connecting rod 316, multiple sets of gripping plates 309 are driven to open outward along the first sliding groove 308, releasing the locking bushing 301. The third waterproof electric slider 318 moves in the opposite direction to the lifting column 303, retracting the locking assembly to the avoidance position to avoid affecting subsequent testing.

[0039] Please see as follows Figure 5 and Figure 6 As shown, the transfer assembly includes a fixing plate 401 for placing the hub bearing 107. The bottom of the transfer bracket 402 is fixed to the bottom of the inspection box 104 by bolts, and the top extends upward and passes through the through groove 103 on the partition plate 102, and is located in the placement cavity. The transfer bracket 402 has an L-shaped structure, and two sets of second slide rails 403 are arranged parallel to each other on one side of its vertical part. The two sets of second slide rails 403 extend in the vertical direction. Two sets of second waterproof electric sliders 404 are arranged on one side of each of the two sets of second slide rails 403. The four sets of second waterproof electric sliders 404 can slide along the corresponding second slide rails 403 respectively. Two waterproof electric sliders 404 are fixedly connected to the lifting frame 405 on one side. Through the synchronous sliding of the four sets of second waterproof electric sliders 404, the lifting frame 405 can be driven to make vertical lifting and lowering movements along the second slide rail 403. A fixed plate 401 is rotatably set on one side of the lifting frame 405 through a bearing. The fixed plate 401 can rotate around the bearing axis. Multiple sets of fixing holes 406 are opened on one side of the fixed plate 401. The multiple sets of fixing holes 406 are evenly distributed along the circumference. The hub bearing 107 is connected to the multiple sets of fixing holes 406 through multiple sets of fixing screws to ensure that the hub bearing 107 remains relatively fixed to the fixed plate 401 during the transportation process.

[0040] Specifically, in use, when the wheel hub bearing 107 to be inspected needs to be transported from the replacement position to the inspection position, the control module 108 first controls the second waterproof electric slider 404 to slide upward along the second slide rail 403, driving the lifting frame 405 and the fixing plate 401 to rise to the replacement position in the placement cavity. At this time, the fixing hole 406 of the fixing plate 401 is in a horizontal position. The inspector places the wheel hub bearing 107 on the fixing plate 401 and connects and fixes the wheel hub bearing 107 to the fixing hole 406 with multiple sets of fixing screws. Then, the second waterproof electric slider 404 is controlled to slide downward along the second slide rail 403, driving the fixing plate 401 and the wheel hub bearing 107 to descend and enter the inspection cavity through the passage groove 103. When the wheel hub bearing 107 descends to the inspection position, the inspection module 108 first controls the second waterproof electric slider 404 to slide downward along the second slide rail 403, driving the fixing plate 401 and the wheel hub bearing 107 to descend. When the rotating shaft 202 of the measuring component is coaxial at its height, the second waterproof electric slider 404 stops sliding. At this time, the axis of the hub bearing 107 coincides with the axis of the rotating shaft 202. Then, the first waterproof electric slider 206 of the measuring component moves along the first slide rail 205, so that the rotating shaft 202 passes through the inner ring of the hub bearing 107 and is fitted on the outside of the connecting shaft section 210, completing the docking of the hub bearing 107 and the rotating shaft 202. Subsequently, the locking component locks the hub bearing 107 on the connecting shaft section 210. Then, the second waterproof electric slider 404 of the transfer component continues to descend a short distance to separate the fixing plate 401 from the hub bearing 107. Then, the second waterproof electric slider 404 is controlled to rise to the clearance position to avoid interfering with subsequent testing.

[0041] As attached Figures 9 to 11As shown, the present invention also provides a positioning method for a wheel hub bearing sealing performance testing device, comprising the following steps: Step S10: Based on the pressure sensor 201, obtain the injection pressure change rate, trigger the shutdown protocol according to the injection pressure change rate, and output the leakage trigger flag. Specifically, the injection pressure change rate refers to the pressure change of the liquid lubricating oil in the injection channel 212 per unit time. Pressure data in the heating tube 214 is collected in real time by the pressure sensor 201. The control module 108 calculates the pressure difference per unit time based on the continuously collected pressure data. This difference reflects the pressure fluctuation of the injection system. If there is a leak in the sealing device of the wheel hub bearing 107, the liquid lubricating oil will flow out from the gap, causing a pressure drop in the injection channel 212, resulting in abnormal fluctuations in the injection pressure change rate. The shutdown protocol is a set of operating procedures preset by the control module 108. When the injection pressure change rate exceeds the set normal range, the control module 108 activates... This process includes stopping the rotation of motor 203, stopping oil pump 218 to interrupt liquid injection, and starting thermal imaging module 106 to take pictures. Its function is to prevent continuous rotation or liquid injection from expanding the leakage range, and at the same time to capture thermal imaging data under leakage conditions in a timely manner. The leakage trigger flag is a status signal output by control module 108 to indicate whether a possible leak has been detected. This flag is a binary signal. For example, when no abnormality is detected, the flag is "0", indicating no leak. When the rate of change of injection pressure exceeds the threshold, the flag switches to "1", indicating that the leakage detection process is triggered. Subsequent steps such as temperature field analysis and leak point location are all started by this flag.

[0042] For example, when inspecting the wheel hub bearing 107, the pressure sensor 201 collects pressure data from the heating tube 214 every 0.5 seconds. The control module 108 calculates that the injection pressure change rate under normal operating conditions is stable within 0.2 kPa / s. When a gap appears in the sealing lip of the wheel hub bearing 107, liquid lubricating oil leaks from the gap. The pressure data collected by the pressure sensor 201 drops from 200 kPa to 195 kPa within 1 second. The calculated injection pressure change rate is 5 kPa / s, which exceeds the preset normal range (0.2 kPa / s). At this time, the control module 108 triggers the shutdown protocol, immediately stops the rotating motor 203 and oil pump 218, and switches the leakage trigger flag from "0" to "1", notifying the system to enter the leakage location stage and providing a start signal for the subsequent acquisition of the original thermal imaging view by the thermal imaging module 106.

[0043] Step S20: Activate the thermal imaging module 106 based on the leakage trigger flag to obtain several frames of original thermal imaging views, obtain the pre-stored temperature-grayscale lookup table, and convert the several frames of original thermal imaging views into several frames of temperature field views according to the temperature-grayscale lookup table. The temperature field views are represented by temperature points. Specifically, based on several frames of original thermal imaging views, pixels are extracted from each frame of the original thermal imaging view. A pre-calibrated temperature-grayscale lookup table is loaded to perform a lookup transformation on each pixel, and each pixel is converted into a temperature point according to the temperature-grayscale lookup table, thus obtaining several frames of temperature field views.

[0044] Furthermore, when the leakage trigger flag changes from "0" to "1", the control module 108 sends a start signal to the thermal imaging module 106. The thermal imaging module 106 then begins to continuously capture images of the wheel hub bearing 107 and its surrounding area at its own set shooting frequency, acquiring several frames of raw thermal imaging views. These raw thermal imaging views use grayscale values ​​to represent the temperature distribution of different areas. The grayscale values ​​correspond to the temperature levels and are used to record the heat distribution state when a leak occurs.

[0045] For example, if the thermal imaging module 106 captures images at a rate of 2 frames per second for 5 seconds, it can acquire 10 original thermal imaging views. Each frame contains 1920×1080 pixels, and the grayscale value of each pixel ranges from 0 to 255. The grayscale value of the area corresponding to the leak point is higher than that of other areas due to the higher temperature. For example, in a certain frame, the grayscale value of the pixels near the leak point is 200, while the grayscale value of the surrounding coolant area is 50.

[0046] It should be noted that the temperature-grayscale reference table is obtained through pre-calibration. During the calibration process, a heat source with a known temperature (such as a heating plate at different temperatures) is placed at the detection position, and the thermal imaging module 106 captures its thermal imaging view, records the grayscale value corresponding to each temperature, establishes a one-to-one correspondence between the grayscale value and the actual temperature, and stores it. For example, a grayscale value of 50 corresponds to a temperature of 15℃ for the anti-rust coolant in the detection chamber 104, a grayscale value of 100 corresponds to a temperature of 30℃, and a grayscale value of 200 corresponds to a temperature of 60℃. The purpose of this reference table is to convert the abstract grayscale values ​​in the original thermal imaging view into quantifiable temperature data, providing a unified temperature benchmark for subsequent analysis. The multi-frame temperature field view is obtained by converting each pixel in the original thermal imaging view through a temperature-grayscale lookup table. Each position in each frame view is represented by a specific temperature value (i.e., temperature point). For example, in a certain frame temperature field view, the position corresponding to the sealing lip of the wheel hub bearing 107 shows a temperature point of 55℃, and the position of the coolant around it shows a temperature point of 15℃. These temperature points together constitute the temperature distribution of the frame view, which makes it easy to intuitively analyze the temperature differences in different areas.

[0047] Step S30: Obtain coolant reference temperature data based on temperature sensor 105, and obtain peak temperature rise view based on several frames of temperature field view and coolant reference temperature data; In this embodiment, step S30 includes the following steps: Step S300: Extract the real-time temperature data of each temperature point in each frame of the temperature field view, and obtain several temperature difference data by subtracting the real-time temperature data from the coolant reference temperature data. Among them, the temperature sensor 105 continuously collects the temperature of the anti-rust coolant in the detection box 104. This temperature is the coolant reference temperature data, which serves as a benchmark for temperature comparison and eliminates the influence of coolant temperature fluctuations on leak detection. The real-time temperature data is the actual temperature value corresponding to each temperature point in several frames of temperature field view. By subtracting the coolant reference temperature data from each real-time temperature data, the obtained temperature difference data can intuitively reflect the temperature rise relative to the coolant at that location. If there is a leak, the temperature difference data at the leak point will be significantly higher than that of the surrounding area.

[0048] Step S301: Convert each temperature point in each frame of the temperature field view into a temperature difference point based on the corresponding temperature difference data, and generate several frames of relative temperature rise field view.

[0049] It should be noted that temperature difference points are a specific representation of temperature difference data, where each location is represented by a "temperature difference value" instead of an "actual temperature value." For example, if the real-time temperature data for a certain temperature point is 55℃ and the coolant reference temperature data is 15℃, then the corresponding temperature difference point is 40℃. The relative temperature rise field view, through the distribution of temperature difference points, highlights the localized temperature rise areas caused by leaks, avoiding interference from minor fluctuations in the overall coolant temperature on the detection results, and making leak-related temperature changes clearer.

[0050] Step S302: Overlay several frames of temperature rise field view with several frames of original thermal imaging view, record the highest temperature difference data of several temperature difference points at each pixel position, obtain the highest temperature difference point, and construct the peak temperature rise view from several highest temperature difference points.

[0051] Understandably, the overlay operation ensures that the temperature difference points correspond precisely to the pixel positions in the original thermal image, avoiding positional deviations. Recording the maximum temperature difference data is to capture the maximum temperature rise during the leak, reducing omissions caused by differences in shooting timing in a single frame view. For example, if the temperature difference points of a certain pixel in three frames are 35℃, 40℃, and 38℃ respectively, then the maximum temperature difference data is 40℃, and the corresponding maximum temperature difference point is 40℃. The peak temperature rise view is composed of the highest temperature difference points of all pixels, presenting the most significant temperature rise area during the leak, providing a reliable temperature distribution basis for subsequent leak source location.

[0052] For example, the reference temperature data of the coolant acquired by the temperature sensor 105 is 15℃. In several frames of temperature field view, the real-time temperature data of the same pixel corresponding to the sealing lip of the wheel hub bearing 107 are 55℃, 53℃, and 54℃, respectively. After calculation in step S300, the temperature difference data are 40℃, 38℃, and 39℃, respectively. Step S301 converts these real-time temperature points into temperature difference points of 40℃, 38℃, and 39℃, generating 3 frames of relative temperature rise field view. The temperature difference point of this pixel is significantly higher than the surrounding temperature difference points of 2℃-5℃ in each frame. Step S302 overlays the 3 frames of relative temperature rise field view with the corresponding original thermal imaging view, records the highest temperature difference data of this pixel as 40℃, as the highest temperature difference point, and records the highest temperature difference data of other pixels. In the final peak temperature rise view, the area corresponding to the sealing lip shows a continuous highest temperature difference point of about 40℃, clearly pointing to the leakage location.

[0053] It should be noted that the coolant reference temperature data is acquired and updated in real time by temperature sensor 105 to ensure the timeliness of temperature difference calculation and avoid the influence of temperature changes caused by long-term storage of coolant on the temperature difference results; after converting the temperature difference data into a relative temperature rise field view, the temperature information unrelated to the leak (such as the small temperature difference caused by natural convection of coolant) can be filtered out, so that the analysis focus is on the temperature rise area caused by the leak; the peak temperature rise view extracts the highest temperature difference point to eliminate possible instantaneous interference in a single frame view (such as temperature fluctuations caused by the brief passage of coolant bubbles), ensuring the stability of subsequent leak source location.

[0054] Step S40: Construct a thermal gradient vector field based on the peak temperature rise view, and generate a divergence distribution map based on the thermal gradient vector field and the peak temperature rise view; In this embodiment, step S40 includes the following steps: Step S400: Extract each maximum temperature difference point in the peak temperature rise view, obtain the horizontal temperature change rate based on the horizontal temperature difference between each maximum temperature difference point and the adjacent maximum temperature difference point, and obtain the vertical temperature change rate based on the vertical temperature difference between each maximum temperature difference point and the adjacent maximum temperature difference point. Specifically, each highest temperature difference point in the peak temperature rise view is extracted. The horizontal temperature change rate is obtained based on the horizontal temperature difference between each highest temperature difference point and its adjacent highest temperature difference points, and the vertical temperature change rate is obtained based on the vertical temperature difference between each highest temperature difference point and its adjacent highest temperature difference points. Adjacent highest temperature difference points refer to the points in the four directions (up, down, left, right) surrounding each highest temperature difference point in the peak temperature rise view. The horizontal temperature difference is the difference in temperature data between the current highest temperature difference point and its adjacent points on the same horizontal line, and the vertical temperature difference is the difference in temperature data between the current highest temperature difference point and its adjacent points on the same vertical line. The horizontal temperature change rate is obtained by dividing the horizontal temperature difference by the horizontal distance between the two points, and the vertical temperature change rate is obtained by dividing the vertical temperature difference by the vertical distance between the two points. Both reflect the rate of temperature change in the horizontal and vertical directions. If a leak exists, the temperature change rate near the leak point will be significantly higher than that of the surrounding area because the temperature of the high-temperature lubricating oil gradually decreases as it diffuses outward from the leak point.

[0055] Step S401: Generate vector arrows for each highest temperature difference point based on the corresponding horizontal and vertical temperature change rates. The vector arrows point in the direction of the fastest temperature increase. Combine several vector arrows into a vector arrow diagram, which is the thermal gradient vector field. Specifically, for each highest temperature difference point, a vector arrow is generated based on the corresponding horizontal and vertical temperature change rates. The vector arrow points in the direction of the fastest temperature increase. Several vector arrows are combined into a vector arrow diagram, which is a thermal gradient vector field. The length of the vector arrow is related to the magnitude of the temperature change rate; the greater the change rate, the longer the arrow, which intuitively reflects the drastic degree of temperature change. For example, around the point of highest temperature difference at the leak point, the rate of temperature change is large in both the horizontal and vertical directions. The generated vector arrow will point to the center of the leak point because the temperature gradually decreases from the leak point outwards, and the direction pointing to the leak point is the direction of the fastest temperature increase. The thermal gradient vector field clearly shows the trend of temperature change through the distribution of vector arrows, helping to distinguish between temperature diffusion caused by leakage and temperature disturbance caused by coolant flow.

[0056] Step S402: Overlay the thermal gradient vector field with the peak temperature rise view to obtain the divergence value of each maximum temperature difference point, and generate a divergence distribution map based on the peak temperature rise view and the divergence value of each corresponding maximum temperature difference point; Specifically, the thermal gradient vector field is overlaid with the peak temperature rise view to obtain the divergence value of each maximum temperature difference point. A divergence distribution map is generated based on the peak temperature rise view and the divergence value of each corresponding maximum temperature difference point. The overlay operation ensures that the vector arrows and the positions of the maximum temperature difference points are accurately aligned, avoiding positional deviations from affecting the analysis. The divergence value is obtained by calculating the pointing relationship of the vector arrows around each maximum temperature difference point, reflecting whether the point is the source of temperature change. The higher the divergence value, the more vector arrows around the point point are pointing to it, and the more concentrated the pointing is, meaning that the point is the core area of ​​temperature rise. The lower the divergence value, the more dispersed the pointing of the vector arrows around the point, or even the existence of arrows pointing away from the point, meaning that the point is not the source of temperature rise. The divergence distribution map uses different colors or values ​​to mark the divergence values ​​of each point, highlighting areas with high divergence values, providing direct evidence for locating the leak source.

[0057] For example, if there is a leak in the sealing lip of the wheel hub bearing 107, the highest temperature difference point at the corresponding position in the peak temperature rise view will show a radial distribution centered on the leak point. In step S400, after extracting these highest temperature difference points, it is found that the temperature difference between the highest temperature difference point at the center of the leak point and the adjacent points in the horizontal direction is large, and the temperature change rate in the horizontal direction is high. The same applies to the vertical direction. The vector arrows generated in step S401 all point from the surrounding area to the center of the leak point, and the length of the arrows gradually increases from the outer periphery to the center. After being superimposed in step S402, the vector arrows around the highest temperature difference point at the center of the leak point are highly concentrated, and the divergence value is significantly higher than that of other areas. This area is marked with a high divergence value in the divergence distribution map, clearly pointing to the location of the leak point.

[0058] Furthermore, the divergence value relates to the direction of the vector arrow. The higher the divergence value, the less the vector arrow points, and the lower the divergence value, the more the vector arrow points. The level of divergence value directly reflects the source characteristics of the temperature rise, which can eliminate the dispersed temperature rise area formed by high-temperature oil droplets carried by the coolant flow, and ensure that the initial location of the leak is located. Step S50: Obtain multiple temperature decay paths based on the divergence distribution map, and verify the leakage source confidence of multiple temperature decay paths to obtain the leakage point coordinates. Based on the leakage point coordinates and the projection view of the wheel hub bearing 3D model, obtain the leakage location parameters of the wheel hub bearing.

[0059] The three-dimensional model of the hub bearing 107 can be obtained in several ways: The CAD model is generated by design software (such as SolidWorks) and contains the dimensions and relative position parameters of each bearing component (sealing lip, outer ring, inner ring, joint, etc.) for mapping leakage coordinates; The three-dimensional point cloud model was obtained by scanning the actual wheel hub bearing 107 with a laser scanner. It consists of the three-dimensional coordinates of millions of points and can restore the fine structure of the bearing surface (such as the curvature of the sealing lip and the concavity and convexity of the seam), which is suitable for comparison with the actual test results. The SD model (Simplified Structural Model) is obtained by simplifying non-critical structures (such as removing chamfers and thread details) based on the CAD model, while retaining the positional relationships of core structures such as sealing devices and joints, and is used to quickly generate projection views.

[0060] Specifically, high divergence values ​​in the divergence distribution map correspond to the core areas of temperature rise. The selection of candidate points by screening the highest temperature difference points with divergence values ​​below a threshold is to focus on potential leak source areas and exclude non-leakage-related high-temperature points caused by interference from coolant flow, etc. The threshold is set based on the parameters of the tested wheel bearing to ensure that the candidate point set covers all potential leak sources. The temperature decay path is traced from each candidate point because leaked high-temperature lubricating oil diffuses and gradually cools. The path reflects the trajectory of temperature decreasing from the leak point outwards. During tracing, the temperature difference between adjacent highest temperature difference points is kept below the tracing threshold to avoid deviating from the leak diffusion direction until the temperature drops to 10% of the highest temperature or reaches the coolant surface. The former ensures that the tracing reaches areas with temperatures close to the environment, while the latter prevents the path from being interrupted by coolant surface reflection. Multiple temperature decay paths together constitute a complete record of the leak diffusion trajectory.

[0061] Furthermore, the confidence verification of the leakage source for multiple temperature decay paths is to distinguish the real leakage source from the interference signal.

[0062] Specifically, multiple points with the highest temperature difference are randomly selected along each temperature decay path. The average offset angle of the line connecting these points is calculated. If the average offset angle is close to the direction perpendicular to the sealing surface of the wheel hub bearing 107 (i.e., the perpendicularity characteristic verification is passed), it indicates that the path conforms to the diffusion law of lubricating oil after leakage from the sealing gap. Conversely, if the average offset angle is chaotic, it is determined to be an interference signal (such as local high temperature driven by coolant eddies). The verified candidate points are determined as the coordinates of the leakage point, which reflect the specific location of the leakage in the detection field of view. By combining these coordinates with the projection view of the three-dimensional model of the wheel hub bearing, the coordinates in the field of view can be converted into parameters relative to the bearing structure, including the distance from the sealing lip and the corresponding joint number, so that the leakage location corresponds to the specific structure of the bearing, such as the sealing device and the end cover joint.

[0063] For example, during the testing of wheel bearing 107, the divergence distribution map showed that there were multiple points with high divergence values ​​and the highest temperature difference near its sealing lip. After screening, the candidate point set contained 3 candidate points. Starting from each candidate point, the temperature decay path was traced. Two of the paths showed a gradual cooling pattern from the candidate point to the surrounding area, and the temperature at the end point dropped to 10% of the highest temperature. The other path was interrupted prematurely due to interference from coolant bubbles. The confidence of the first two paths was verified. Five points with the highest temperature difference were randomly selected to calculate the average offset angle. It was found that the average offset angle of one path was perpendicular to the sealing lip surface (the perpendicularity characteristic was verified). The other path was judged as interference due to a large angle deviation. The candidate points that passed the verification were determined as the coordinates of the leakage point. After comparing the coordinates with the projection view of the 3D model of the wheel bearing, the output leakage location parameters clearly pointed to the third joint between the sealing lip and the outer ring.

[0064] Understandably, by converting the original thermal imaging view into a temperature field view and extracting the peak temperature rise view from the coolant reference temperature data acquired by the temperature sensor 105, the region with the highest temperature difference can be focused on, filtering out irrelevant temperature fluctuations caused by convection, bubbles, etc., in the low-temperature rust-preventing coolant environment, thus concentrating the analysis scope on possible leakage areas. By constructing a thermal gradient vector field and generating a divergence distribution map, and using vector arrows generated by the temperature change rates in the horizontal and vertical directions, the core region with the fastest temperature rise can be clearly identified, eliminating temperature diffusion interference caused by coolant flow, and pinpointing the specific location of the leakage source based on the temperature change pattern. Furthermore, the tracking and confidence verification of the temperature decay path further filters out the real leakage source through the physical laws of leakage diffusion, avoiding misjudgment. Finally, by combining the projection view of the three-dimensional model of the wheel hub bearing, the detection results can be directly associated with the specific structure of the wheel hub bearing 107, solving the problem that traditional sealing detection devices can only determine whether there is a leak but cannot locate the specific leak location.

[0065] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A device for testing the sealing performance of wheel hub bearings, characterized in that, include: The experimental chamber has a placement chamber and a testing chamber formed by a partition plate. The placement chamber and the testing chamber are connected by a through groove on the partition plate. The test chamber is located at the bottom of the test chamber and contains rust-preventive coolant. A cooling mechanism is installed inside the test chamber to cool the rust-preventive coolant. A temperature sensor is installed inside the test chamber to acquire the reference temperature data of the coolant. A thermal imaging module is installed on one side of the test chamber to acquire the original thermal imaging view. The detection component is used to simulate the working conditions of the wheel hub bearing, while injecting liquid lubricating oil into the wheel hub bearing and obtaining the rate of change of injection pressure through a pressure sensor. The transfer assembly is installed at the bottom inside the inspection box and passes through the through slot at the top and is located in the placement cavity. The transfer assembly is used to transport the wheel hub bearing to be inspected to the replacement position in the placement cavity or the inspection position in the inspection cavity. When the wheel hub bearing is located in the inspection position, its rotation axis coincides with the rotation axis of the inspection assembly. The thermal imaging module is located at one end of the rotation axis of the inspection assembly. Locking assembly, used to lock the hub bearing of the detection position to the detection assembly; The control module is installed on the switchable door panel on one side of the experimental chamber. The control module is used to control the operation of the testing device.

2. The wheel hub bearing sealing performance testing device according to claim 1, characterized in that: The testing assembly includes a rotating shaft and a rotating motor for simulating the working conditions of a wheel hub bearing. A first mounting base is provided inside the testing box. Two sets of first slide rails are provided on the top of the first mounting base. Two sets of first waterproof electric sliders are respectively provided on the two sets of first slide rails. The tops of the two sets of first waterproof electric sliders are connected to a first movable frame. A waterproof box is provided on one side of the first movable frame. A rotating motor is provided inside the waterproof box. The rotating motor is used to drive the rotating shaft to rotate around its own axis. A through hole is provided on one side of the waterproof box, through which a rotating shaft is inserted. One end of the rotating shaft is connected to the main shaft of the rotating motor by two sets of meshing gears. A connecting shaft section for connecting to the hub bearing is provided on the rotating shaft, and a sealed bearing is provided in the through hole corresponding to the rotating shaft.

3. The wheel hub bearing sealing performance testing device according to claim 2, characterized in that: The detection assembly also includes an oil injection channel for injecting liquid lubricating oil into the wheel hub bearing. The rotating shaft and connecting shaft section have oil injection channels corresponding to the wheel hub bearing. The position of the sealing structure on the wheel hub bearing corresponds to the oil outlet end of the oil injection channel. A heating chamber is installed inside the waterproof box. The heating chamber is equipped with a heating tube and a heat pipe heater. The heat pipe heater surrounds the heating tube and heats the lubricating oil it delivers. A pressure sensor is installed at the bottom of the heating tube. One end of the heating tube is connected to the oil inlet end of the oil injection channel through a rotating joint. An oil storage tank is installed inside the waterproof box. An oil pump is installed on the top of the oil storage tank. The oil pump connects the other end of the heating tube to the oil storage tank through a pipeline.

4. The wheel hub bearing sealing performance testing device according to claim 3, characterized in that: The locking assembly includes a locking bushing that locks the hub bearing onto the connecting shaft section. A second mounting base is provided inside the testing box. A lifting column is provided above the second mounting base. A waterproof locking motor is provided on one side of the lifting column. The waterproof locking motor is used to install the locking bushing on one side of the connecting shaft section. A rotating plate is connected to the shaft end of the waterproof locking motor. A gripping structure and a waterproof electric telescopic rod are provided on one side of the rotating plate. The waterproof electric telescopic rod is used to drive the gripping structure to grip the locking bushing. The second mounting base has two sets of third slide rails on its top, each set of third slide rails is equipped with a third waterproof electric slider, and the top of each set of third waterproof electric sliders is connected to the lifting platform. The top of the lifting platform has a lifting groove, and the lifting column slides through the lifting groove. The lifting column is used to move the gripping structure and the waterproof locking motor to the detection position or avoidance position in the detection chamber. When the gripping structure and the waterproof locking motor are in the detection position, their rotation axis coincides with the rotation axis of the wheel hub bearing and the rotation axis of the detection component located in the detection position. A rack is provided on one side of the lifting column, and a waterproof lifting motor is provided on one side of the lifting platform. A gear is provided on the main shaft of the waterproof lifting motor that meshes with the rack.

5. The wheel hub bearing sealing performance testing device according to claim 1, characterized in that: The transfer assembly includes a fixing plate for placing the wheel hub bearing. The bottom of the transfer bracket is installed inside the inspection box, and the top passes through the through slot and is located in the placement cavity. Two sets of second slide rails are provided on one side of the transfer bracket. Two sets of second waterproof electric sliders are provided on one side of each of the two sets of second slide rails. One side of each of the four sets of second waterproof electric sliders is connected to the lifting frame. A fixing plate is rotatably installed on one side of the lifting frame. Multiple sets of fixing holes are opened on one side of the fixing plate. The wheel hub bearing is connected to the multiple sets of fixing holes through multiple sets of fixing screws.

6. A positioning method for a wheel hub bearing sealing performance testing device, characterized in that, It includes the following steps: The injection pressure change rate is obtained based on the pressure sensor, and a shutdown protocol is triggered and a leakage trigger flag is output based on the injection pressure change rate. The thermal imaging module is activated based on the leakage trigger flag to obtain several frames of original thermal imaging views. A pre-stored temperature-grayscale lookup table is obtained, and the several frames of original thermal imaging views are converted into several frames of temperature field views according to the temperature-grayscale lookup table. The temperature field views are represented by temperature points. The reference temperature data of the coolant is obtained based on the temperature sensor, and the peak temperature rise view is obtained based on several frames of temperature field view and the reference temperature data of the coolant. A thermal gradient vector field is constructed based on the peak temperature rise view, and a divergence distribution map is generated based on the thermal gradient vector field and the peak temperature rise view. Multiple temperature decay paths are obtained based on the divergence distribution map, and the leakage source confidence of multiple temperature decay paths is verified to obtain the coordinates of the leakage point. Based on the coordinates of the leakage point and the projection view of the 3D model of the wheel hub bearing, the leakage location parameters of the wheel hub bearing are obtained.

7. The positioning method of the wheel hub bearing sealing performance testing device according to claim 6, characterized in that, The process of converting several frames of original thermal imaging views into several frames of temperature field views based on a temperature-grayscale lookup table includes: Pixels are extracted from each frame of the original thermal imaging view based on several frames of original thermal imaging views. A pre-calibrated temperature-grayscale lookup table is loaded to perform a lookup transformation on each pixel, and each pixel is converted into a temperature point according to the temperature-grayscale lookup table, resulting in several frames of temperature field views.

8. The positioning method of the wheel hub bearing sealing performance testing device according to claim 6, characterized in that, The method for obtaining the peak temperature rise view based on several frames of temperature field view and coolant reference temperature data includes: Extract real-time temperature data for each temperature point in each frame of the temperature field view, and obtain several temperature difference data by subtracting several real-time temperature data from the coolant reference temperature data; Each temperature point in each frame of the temperature field view is converted into a temperature difference point based on the corresponding temperature difference data, generating several frames of relative temperature rise field view; Several frames of temperature rise field view are overlaid with several frames of original thermal imaging view. The highest temperature difference data of several temperature difference points at each pixel position are recorded to obtain the highest temperature difference point. Several highest temperature difference points are then used to construct a peak temperature rise view.

9. The positioning method of the wheel hub bearing sealing performance testing device according to claim 8, characterized in that, The process of constructing a thermal gradient vector field based on a peak temperature rise view, and generating a divergence distribution map based on the thermal gradient vector field and the peak temperature rise view, includes: Extract each maximum temperature difference point in the peak temperature rise view, obtain the horizontal temperature change rate based on the horizontal temperature difference between each maximum temperature difference point and the adjacent maximum temperature difference point, and obtain the vertical temperature change rate based on the vertical temperature difference between each maximum temperature difference point and the adjacent maximum temperature difference point. For each highest temperature difference point, a vector arrow is generated based on the corresponding horizontal and vertical temperature change rates. The vector arrow points in the direction of the fastest temperature increase. Several vector arrows are combined into a vector arrow diagram, which is the thermal gradient vector field. The thermal gradient vector field is overlaid with the peak temperature rise view to obtain the divergence value of each maximum temperature difference point. A divergence distribution map is generated based on the peak temperature rise view and the divergence value of each corresponding maximum temperature difference point. The divergence value represents the direction of the vector arrows; The higher the divergence value, the fewer points the vector arrow points to; The lower the divergence value, the more the vector arrow points.

10. The positioning method of the wheel hub bearing sealing performance testing device according to claim 9, characterized in that, The method further includes: In the divergence distribution map, all the highest temperature difference points with divergence values ​​below the threshold are selected, and these highest temperature difference points are constructed into a candidate point set. Starting from each candidate point, the temperature difference between adjacent highest temperature difference points is lower than the tracking threshold and is tracked upwards until the temperature drops to 10% of the highest temperature or reaches the surface of the coolant, generating multiple temperature decay paths. Leakage source confidence verification is performed for multiple temperature decay paths. Multiple highest temperature difference points are randomly selected on the temperature decay path, and the average offset angle of the temperature decay path corresponding to the multiple highest temperature difference points is calculated to verify the vertical characteristics. If the verification is successful, the candidate point is selected as the leakage point coordinate; otherwise, the candidate point is judged as an interference signal.

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