Oil seal air tightness detection equipment of electric vehicle driving motor

Abstract

The invention discloses oil seal air tightness detection equipment for an electric vehicle driving motor. The oil seal air tightness detection equipment comprises a rack, a conveying module and an air tightness detection module. The conveying module is matched with a jacking limiting assembly through a roller conveying line, and automatic feeding, accurate positioning and rigid locking of the motor are achieved. The air tightness detection module comprises an air tightness instrument, an air tightness pressing module and an automatic point inspection module. A pressing air cylinder drives an air tightness pressing head to conduct sealing detection on the motor oil seal. The equipment innovatively adopts a jacking-support changing structure, stable stress is provided by a supporting plate, and detection micro-motion is eliminated; an automatic point inspection function is integrated, a zero leakage comparison tool can be periodically called to carry out on-line self-calibration on the system, and precision drift is effectively early warned. The motor oil seal airtightness detection device realizes full automation of the detection process, has the characteristics of high precision, high stability and intelligent self-maintenance, and ensures the consistency and long-term reliability of motor oil seal airtightness detection.

Description

Technical Field

[0001] This invention relates to the field of new energy vehicle drive system technology, and in particular to an oil seal airtightness testing device for electric vehicle drive motors. Background Technology

[0002] As a core power component, the airtightness of the oil seals in electric vehicle drive motors directly affects motor reliability and overall vehicle safety. Traditional airtightness testing relies heavily on manual operation or semi-automatic equipment, which suffers from low positioning accuracy, insufficient testing efficiency, and poor result consistency. Furthermore, the equipment's accuracy is prone to drift over long-term use, and it lacks effective online self-calibration capabilities. With the increasing production capacity of electric vehicles, the industry urgently needs a highly automated, stable, and reliable intelligent airtightness testing device capable of periodic self-inspection to ensure comprehensive and controllable control over the sealing quality of motor oil seals. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the main objective of this invention is to provide a fully automated and high-precision testing device for the oil seal air tightness of electric vehicle drive motors with integrated self-calibration function.

[0004] To achieve the above objectives, the present invention provides the following technical solution: an oil seal airtightness testing device for an electric vehicle drive motor, comprising a frame and a conveying module and an airtightness testing module disposed within the frame; the conveying module includes a roller conveyor line running through the frame, the roller conveyor including two rows of short roller lines and an empty area located between the two rows of short roller lines, the empty area being provided with a motor bearing assembly and a lifting and limiting assembly located below the motor bearing assembly; the motor bearing assembly includes a tray and positioning columns and clamps fixedly disposed on the tray, the lifting and limiting assembly including a support plate, a lifting cylinder, a top plate, multiple reaction support units disposed on the support plate, and components disposed at both ends of the support plate to block the bearing cylinder. The disc has a blocking cylinder, the support plate is fixedly mounted on the frame of the roller conveyor line, the lifting cylinder is fixedly mounted at the center of the support plate, the piston rod of the lifting cylinder is fixedly connected to the top plate, a guide assembly consisting of multiple first linear bearings and first guide rods is provided between the top plate and the support plate, a fixing block is fixedly mounted below each positioning post at the bottom of the top plate, and a reaction force support unit is provided below each fixing block. The reaction force support unit includes a reaction force support cylinder, a limiting groove, and a limiting block that slides in the limiting groove. The piston rod of the reaction force support cylinder is fixedly connected to the limiting block. The roller conveyor line is also equipped with an infeed photoelectric sensor and an outfeed photoelectric sensor capable of detecting the drive motor. The airtightness testing module includes an airtightness testing frame mounted above the conveying module. The airtightness testing frame is equipped with an airtightness tester, an airtightness pressing module, and an automatic inspection module. An air storage tank connected to the airtightness tester is located inside the frame. The airtightness pressing module includes a fixed base plate, a slide rail mounted on the fixed base plate, a mounting plate slidably connected to the slide rail via a slider, and a pressing cylinder mounted upside down on the mounting plate. A transverse cylinder connected to the mounting plate is mounted on the fixed base plate. The transverse cylinder pulls the mounting plate along the slide rail via a piston rod. A slotted groove is provided on the fixed base plate. The piston rod of the pressing cylinder passes through the mounting plate and the slotted groove. A mounting base is fixedly connected to the end of the piston rod. The mounting base is connected via an insert... The automatic inspection assembly includes a self-inspection fixture buffer station set on the top of the airtightness test frame and a self-inspection station fixed to the bottom of the fixed base plate by several connecting rods. The self-inspection fixture buffer station includes several oil seal fixtures to be tested and a zero-leakage comparison fixture placed on the placement plate. The self-inspection station includes a self-inspection base plate fixedly connected to the several connecting rods. The oil seal fixtures to be tested or the zero-leakage comparison fixture are detachably connected to the self-inspection base plate by screws. During the test, the transverse cylinder can drive the airtightness pressing module to move along the slide rail and the strip groove to the self-inspection station. The pressing cylinder drives the airtightness pressure head to press down on the oil seal fixtures to be tested or the zero-leakage comparison fixture on the self-inspection base plate to perform a sealing test.During operation, the drive motor is mounted on the tray, which moves with the roller conveyor. After the feed photoelectric sensor detects the drive motor, the roller conveyor stops conveying the tray below the airtight pressing module. At this point, the blocking cylinder holds the tray in place, and the lifting cylinder lifts the tray by moving the top plate. The reaction support cylinder moves the limit block to directly below the fixed block at the bottom of the top plate. Then, the lifting cylinder lowers the top plate and tray, and the fixed block falls onto the limit block. At this point, the support plate replaces the lifting cylinder to provide force support. The pressing cylinder of the airtight pressing module lowers the airtight pressure head to the oil seal of the drive motor. The sealing cavity of the oil seal is inflated and an airtightness test is performed. After the test, the pressing cylinder retracts the airtight pressure head, and the lifting cylinder again lifts the tray by moving the top plate. At this point, the reaction support cylinder moves the limit block away from directly below the fixed block. Then, the lifting cylinder lowers the top plate and tray, the blocking cylinder retracts, and the roller conveyor moves the tray out of the equipment.

[0005] Preferably, each column of short rollers is provided with a baffle on its outer side, and the side of the tray is provided with rollers that contact the baffle.

[0006] Preferably, the airtightness meter is connected to a standard tank.

[0007] Preferably, each of the plurality of oil seal fixtures to be tested and the zero-leakage fixture is provided with a foolproof hole at both ends.

[0008] Preferably, the bottom of the mounting base is provided with a bottom hole, the airtight pressure head includes a protrusion that can be inserted into the bottom hole, a through hole is provided through the bottom hole, and a mating hole that can communicate with the through hole is provided through the protrusion. The pin can enter from the through hole and be inserted into the mating hole. The bottom hole and the protrusion are both waist-shaped.

[0009] Preferably, the mounting plate is provided with a linear auxiliary component, which includes a plurality of second linear bearings disposed on the mounting plate, a plurality of second guide rods inserted in the plurality of second linear bearings, and an upper connecting plate and a lower connecting plate fixing the upper and lower ends of the plurality of second guide rods. The end of the piston rod of the pressing cylinder is fixed on the lower connecting plate.

[0010] Preferably, a connecting shaft is fixedly provided on the lower connecting plate, the end of the connecting shaft is provided with a tapered portion, a buffer spring is sleeved on the connecting shaft, the mounting base includes an upper seat body sleeved on the connecting shaft and a lower seat body connected to the upper seat body by bolts, the through hole is provided on the lower seat body, the bottom of the upper seat body abuts against the tapered portion, and the top of the upper seat body abuts against the buffer spring.

[0011] This invention has the following advantages over the prior art, mainly reflected in three aspects: high precision, high stability, and intelligent self-maintenance:

[0012] Fully automated and high-precision testing: Through the precise coordination of the roller conveyor line, lifting and limiting components, and airtight pressing module, the equipment achieves full automation of the entire process from motor feeding, precise positioning, rigid locking to automatic testing. The unique "lifting-support changing" structure transforms the load-bearing body from a cylinder into a rigid support plate. Combined with the linear auxiliary guidance of the pressing module, it completely eliminates micro-displacement and vibration during the testing process, providing an extremely stable and highly repeatable physical benchmark for airtightness testing, ensuring the consistency and reliability of the test results.

[0013] Online self-calibration and long-term stability: The equipment integrates an innovative automatic inspection module, which can be programmatically invoked to move the testing head to the self-inspection station for periodic testing of a preset "zero-leakage comparison fixture." This function enables online self-diagnosis and calibration of the airtightness meter, sensors, and the entire detection circuit. It can proactively detect and warn of accuracy drift within the equipment itself, fundamentally solving the problem of traditional equipment failing to recognize accuracy loss after long-term use, thus ensuring long-term controllable production quality.

[0014] Flexible and error-proof design: The airtight pressure head adopts a quick-change pin connection with an oblong shape to prevent misalignment, facilitating rapid replacement to adapt to different product models. Details such as pallet guides and error-proof tooling holes effectively prevent misalignment and erroneous operation during material handling and self-inspection. The overall design pursues high-precision automation while also considering the flexibility of production line changeovers and the robustness of system operation, significantly improving the overall practical value and production efficiency of the equipment. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of an oil seal airtightness testing device for an electric vehicle drive motor according to the present invention.

[0016] Figure 2 This is a schematic diagram of the structure of the present invention with the frame omitted;

[0017] Figure 3 This is a schematic diagram of the conveying module of the present invention;

[0018] Figure 4 This is a schematic diagram of the structure of the motor bearing assembly of the present invention;

[0019] Figure 5 This is a schematic diagram of the lifting and limiting component of the present invention. Figure 1 ;

[0020] Figure 6 This is a schematic diagram of the lifting and limiting component of the present invention. Figure 2 ;

[0021] Figure 7 for Figure 6 Enlarged structural diagram of section A in the middle;

[0022] Figure 8 This is a simplified diagram showing the positional relationship during the testing of the drive motor product of the present invention;

[0023] Figure 9 This is a schematic diagram of the airtightness detection module of the present invention. Figure 1 ;

[0024] Figure 10 This is a schematic diagram of the airtightness detection module of the present invention. Figure 2 ;

[0025] Figure 11 This is a schematic diagram of the structure of the airtight pressing module of the present invention. Figure 1 ;

[0026] Figure 12 This is a schematic diagram of the structure of the airtight pressing module of the present invention. Figure 2 ;

[0027] Figure 13 for Figure 12 Cross-sectional view of section AA.

[0028] In the diagram: 1. Frame; 2. Conveying module; 3. Air tightness testing module; 4. Roller conveyor line; 5. Short roller conveyor line; 6. Idle area; 7. Motor bearing assembly; 8. Lifting and limiting assembly; 9. Pallet; 10. Positioning column; 11. Support plate; 12. Lifting cylinder; 13. Top plate; 14. Blocking cylinder; 15. First linear bearing; 16. First guide rod; 17. Fixing block; 18. Reaction support cylinder; 19. Limiting groove; 20. Limiting block; 21. Feed photoelectric sensor; 22. Discharge photoelectric sensor; 23. Air tightness testing frame; 24. Air tightness tester; 25. Air tightness pressing module; 26. Automatic inspection module; 27. Air storage tank; 28. Fixed base plate; 29. ​​Slide rail; 30. 31. Mounting plate; 32. Pressing cylinder; 33. Horizontal cylinder; 34. Strip groove; 35. Mounting base; 36. Pin; 37. Airtight pressure head; 38. Self-inspection tooling buffer station; 39. Connecting rod; 40. Self-inspection station; 41. Placement plate; 42. Oil seal to be tested tooling; 43. Zero leakage comparison tooling; 44. Self-inspection base plate; 45. Baffle; 46. Roller; 47. Standard tank; 48. Anti-foolproof hole; 49. Bottom hole; 50. Protrusion; 51. Butt joint hole; 52. Second linear bearing; 53. Second guide rod; 54. Upper connecting plate; 55. Lower connecting plate; 56. Connecting shaft; 57. Tapered part; 58. Buffer spring; 59. Upper seat body; 60. Lower seat body; 51. Drive motor. Detailed Implementation

[0029] The invention will now be further described with reference to the accompanying drawings.

[0030] like Figure 1As shown, an oil seal airtightness testing device for an electric vehicle drive motor includes a frame 1 and a conveying module 2 and an airtightness testing module 3 disposed within the frame 1. The conveying module 2 includes a roller conveyor line 4 that runs through the frame 1. The roller conveyor includes two rows of short roller lines 5 and an empty area 6 located between the two rows of short roller lines 5. A motor bearing assembly 7 and a lifting and limiting assembly 8 located below the motor bearing assembly 7 are disposed in the empty area 6. The motor bearing assembly 7 includes a tray 9 and positioning posts 10 and clamps fixedly disposed on the tray 9. The lifting and limiting assembly 8 includes a support plate 11, a lifting cylinder 12, a top plate 13, multiple reaction support units disposed on the support plate 11, and blocking cylinders 14 disposed at both ends of the support plate 11 to block the tray 9. The support plate 11 is fixed. The lifting cylinder 12 is fixedly installed at the center of the support plate 11 on the frame of the roller conveyor line 4. The piston rod of the lifting cylinder 12 is fixedly connected to the top plate 13. A plurality of guide components consisting of a first linear bearing 15 and a first guide rod 16 are provided between the top plate 13 and the support plate 11. A fixing block 17 is also fixedly installed below each positioning post 10 at the bottom of the top plate 13. A reaction force support unit is provided below each fixing block 17. The reaction force support unit includes a reaction force support cylinder 18, a limiting slide groove 19, and a limiting block 20 that slides in the limiting slide groove 19. The piston rod of the reaction force support cylinder 18 is fixedly connected to the limiting block 20. The roller conveyor line 4 is also equipped with an infeed photoelectric sensor 21 and an outfeed photoelectric sensor 22 that can detect the drive motor 60.The airtightness testing module 3 includes an airtightness testing frame 23 mounted above the conveying module 2. The airtightness testing frame 23 is equipped with an airtightness tester 24, an airtightness pressing module 25, and an automatic inspection module 26. An air storage tank 27 connected to the airtightness tester 24 is located inside the frame 1. The airtightness pressing module 25 includes a fixed base plate 28, a slide rail 29 mounted on the fixed base plate 28, a mounting plate 30 slidably connected to the slide rail 29 via a slider, and a pressing cylinder 31 invertedly mounted on the mounting plate 30. A transverse cylinder 32 connected to the mounting plate 30 is mounted on the fixed base plate 28. The transverse cylinder 32 pulls the mounting plate 30 along the slide rail 29 via a piston rod. A strip groove 33 is provided on the fixed base plate 28. The piston rod of the pressing cylinder 31 passes through the mounting plate 30 and the slot 33. A mounting base 34 is fixedly connected to the end of the piston rod. The mounting base 34 is connected to an airtight pressure head 36 via a pin 35. The automatic inspection assembly includes a self-inspection fixture buffer station 37 located on top of the airtightness test frame 23 and a self-inspection station 39 fixed below the fixed base plate 28 via several connecting rods 38. The self-inspection fixture buffer station 37 includes several oil seal fixtures 41 to be tested placed on the placement plate 40 and a zero-leakage comparison fixture 42. The self-inspection station 39 includes a self-inspection base plate 43 fixedly connected to the several connecting rods 38. The oil seal fixtures 41 to be tested or the zero-leakage comparison fixture 42 are detachably connected to the self-inspection base plate 43 via screws. During testing, the transverse cylinder 32 drives the airtight pressing module 25 to move along the slide rail 29 and the strip groove 33 to the self-inspection station 39. The pressing cylinder 31 drives the airtight pressure head 36 to press down onto the oil seal tooling 41 to be tested or the zero-leakage comparison tooling 42 on the self-inspection base plate 43 for sealing testing. During operation, the drive motor 60 is installed on the tray 9, and the tray 9 moves with the roller conveyor line 4. After the feed photoelectric sensor 21 detects the drive motor 60, the roller conveyor line 4 transports the tray 9 to below the airtight pressing module 25 and then stops. At this time, the blocking cylinder 14 abuts and fixes the tray 9, and the lifting cylinder 12 drives the top plate 13 to lift the tray 9. The reaction support cylinder 18 drives the limit block 20 to move to Directly below the fixing block 17 at the bottom of the top plate 13, the lifting cylinder 12 then lowers the top plate 13 and tray 9, causing the fixing block 17 to fall onto the limiting block 20. At this time, the support plate 11 replaces the lifting cylinder 12 to provide force support. The pressing cylinder 31 of the airtight pressing module 25 lowers the airtight pressure head 36 to the oil seal of the drive motor 60. The sealing cavity of the oil seal is inflated and an airtightness test is performed. After the test is completed, the pressing cylinder 31 retracts the airtight pressure head 36, and the lifting cylinder 12 again lifts the top plate 13 to raise the tray 9. At this time, the reaction support cylinder 18 moves the limiting block 20 away from directly below the fixing block 17. Then, the lifting cylinder 12 lowers the top plate 13 and tray 9, the blocking cylinder 14 retracts, and the roller conveyor 4 moves the tray 9 out of the equipment.

[0031] This invention provides a highly automated, self-calibrating testing device for the airtightness of oil seals in electric vehicle drive motors, aiming to address industry pain points such as low positioning accuracy, insufficient efficiency, poor result consistency, and lack of long-term equipment stability in traditional testing methods. Its core technology revolves around a logical chain of "precise positioning - stable pressure application - closed-loop testing - online self-calibration," achieving full automation of the testing process and closed-loop management of quality monitoring through precise coordination of mechanical structure, pneumatic actuation, and sensor control.

[0032] Its overall architecture and workflow are as follows: The equipment consists of two core modules: a conveying and positioning module and an airtightness detection and self-calibration module. Its workflow follows a rigorous sequential control cycle:

[0033] Loading and conveying: The drive motor 60 to be inspected is fixed on a special pallet 9 with positioning posts 10 and clamps, and the pallet 9 is placed on the roller conveyor line 4. The baffle 44 on the outside of the conveyor line cooperates with the rollers 45 on the side of the pallet 9 to ensure that the pallet 9 runs in a straight line along the predetermined path during the transmission process and prevents deviation.

[0034] Precise Positioning and Rigid Support: When pallet 9 arrives at the inspection station, it is first axially intercepted by blocking cylinder 14. Then, lifting cylinder 12 actuates, lifting the entire pallet 9 and motor via top plate 13 and fixing block 17, detaching them from the roller conveyor. Immediately afterward, reaction support cylinder 18 in the reaction support unit pushes limit block 20 to slide directly below fixing block 17. Lifting cylinder 12 then descends, firmly placing fixing block 17 on limit block 20. At this point, the weight of the motor and subsequent inspection pressure are transmitted through fixing block 17, limit block 20, and limit groove 19, ultimately reaching the robust support plate 11. This "lift-support replacement" process is crucial; it converts dynamic support into static rigid support, completely eliminating the risk of slight subsidence caused by air source fluctuations or cylinder pressure holding, providing an extremely stable and drift-free reference platform for inspection.

[0035] Air tightness test execution: The pressing cylinder 31 of the air tightness pressing module 25 drives the air tightness pressure head 36 downward, pressing the sealing surface of the motor oil seal to form a sealed cavity. The air tightness tester 24 fills the sealed cavity with gas at a certain pressure, and monitors the pressure change within a specified time through a high-precision sensor (differential pressure method or direct pressure method) to determine whether the leakage rate of the oil seal is qualified. To ensure the verticality and stability of the pressing process, the linear auxiliary components (second linear bearing 51 and second guide rod 52) provide additional precision guidance for the piston rod of the pressing cylinder 31, preventing poor sealing or equipment wear caused by lateral forces.

[0036] Unloading and Transfer: After the inspection is completed, the pressing cylinder 31 is lifted, the lifting cylinder 12 lifts the tray 9 again to make the fixing block 17 disengage from the limiting block 20, the reaction support cylinder 18 retracts the limiting block 20, and finally the lifting cylinder 12 descends to put the tray 9 back on the roller line, the blocking cylinder 14 is released, and qualified and unqualified products are transported to different areas.

[0037] Online automatic inspection (self-calibration): This is the core of the equipment's intelligent operation and long-term reliability. The equipment can initiate a self-check program periodically or upon command. At this time, the transverse cylinder 32 pulls the entire airtight pressing module 25 laterally along the slide rail 29, moving it from the motor detection station to above the self-check station 39. A zero-leakage comparison fixture 42 or a test oil seal fixture 41 is installed on the self-check station 39 via a quick-change mechanism. The pressing module performs the same test on the standard fixture. By comparing the test results with the known state of the standard fixture (zero leakage or with a standard leakage hole), the accuracy of the airtightness meter 24, the pressing seal state, and even the entire testing circuit can be calibrated or verified, achieving self-diagnosis and accuracy traceability of the equipment.

[0038] This invention comprehensively utilizes the principles of mechanical positioning, pneumatic control, sensor feedback, and closed-loop calibration. Its technological advancement lies not only in the automation of single-point detection but also in the construction of an intelligent detection system capable of self-verification and maintaining stable accuracy over the long term. A "rigid support replacement" mechanism ensures stable detection benchmarks, while "moving pressure head + self-inspection station 39" enables online self-calibration. A series of optimized design details (foolproofing, buffering, precision guidance, etc.) ensure high reliability and high precision throughout the entire process, perfectly meeting the electric vehicle industry's production requirements for high-quality, high-efficiency, and fully traceable core components.

[0039] Preferably, each short roller conveyor 5 has a baffle 44 on its outer side, and the pallet 9 has rollers 45 on its side that contact the baffle 44. This design aims to solve the problem of lateral displacement or jamming that may occur on the long roller conveyor 4. The baffle 44 on the outer side of each short roller conveyor 5 forms a physical guide track. The rollers 45 mounted on the side of the pallet 9 maintain rolling contact with the baffle 44. This design converts sliding friction into rolling friction, which can effectively constrain the lateral freedom of the pallet 9, ensuring its precise movement to the lifting position, and greatly reduce motion resistance, improve conveying smoothness, and reduce drive load.

[0040] Preferably, the airtightness tester 24 is connected to a standard container 46. This is intended to improve the accuracy, stability, and adaptability of the airtightness test to workpieces of different volumes. The standard container 46 is a reference container with a known fixed volume. In differential pressure testing, the airtightness tester 24 simultaneously inflates both the standard container 46 and the sealed cavity of the workpiece under test. Because the standard container 46 is perfectly sealed, the pressure difference between the two will be purely caused by leakage from the workpiece under test, eliminating common-mode interference such as air source pressure fluctuations and temperature changes, resulting in higher detection accuracy. It also expands the equipment's ability to test motors of different sizes (different cavity volumes).

[0041] Preferably, each of the plurality of oil seal fixtures 41 to be tested and the zero-leakage fixture is provided with a foolproof hole 47 at both ends.

[0042] The purpose is to prevent incorrect installation of fixtures at self-inspection station 39, ensuring the effectiveness and reliability of the self-calibration process. Positioning pins are installed at specific locations on the self-inspection base plate 43, and corresponding, differently positioned anti-foolproof holes 47 are provided at the bottom of the oil seal fixture 41 to be tested and the zero-leakage comparison fixture 42. Only when the fixture model matches the self-inspection program settings can the holes be aligned, allowing the fixture to be successfully installed. This physically eliminates the possibility of misusing ordinary fixtures as standard zero-leakage fixtures, ensuring the absolute accuracy of the self-calibration benchmark.

[0043] Preferably, the bottom of the mounting base 34 is provided with a bottom hole 48, the airtight pressure head 36 includes a protrusion 49 that can be inserted into the bottom hole 48, a through hole is provided through the bottom hole 48, and a mating hole 50 that can communicate with the through hole is provided through the protrusion 49. The pin 35 can enter from the through hole and be inserted into the mating hole 50. The bottom hole 48 and the protrusion 49 are both waist-shaped.

[0044] The aim is to achieve rapid, accurate, and reliable replacement and connection of the airtight pressure head 36 to accommodate the oil seal interfaces of different motor models. Both the bottom hole 48 of the mounting base 34 and the protrusion 49 of the airtight pressure head 36 are designed in an oblong shape, a mistake-proof design that ensures the pressure head can only be inserted in one correct orientation. After insertion, the through holes of both align with the mating holes 50, and inserting the pin 35 completes circumferential and axial fixation. This connection method is more resistant to vibration and loosening than a pure threaded connection, and allows for faster replacement, facilitating quick model changes on the production line.

[0045] Preferably, the mounting plate 30 is provided with a linear auxiliary component, which includes a plurality of second linear bearings 51 disposed on the mounting plate 30, a plurality of second guide rods 52 inserted in the plurality of second linear bearings 51, and an upper connecting plate 53 and a lower connecting plate 54 fixing the upper and lower ends of the plurality of second guide rods 52. The end of the piston rod of the pressing cylinder 31 is fixed on the lower connecting plate 54.

[0046] The purpose is to enhance the rigidity of the pressing cylinder 31 in the direction of movement, so as to ensure that the pressing process is absolutely vertical and without shaking.

[0047] The pressing cylinder 31 itself may have slight radial clearance. By adding an independent guiding system consisting of a second linear bearing 51 and a second guide rod 52 to the mounting plate 30, and rigidly connecting it to the piston rod end (through the upper and lower connecting plates 54), ultra-precise additional guidance is provided for the pressing action. This greatly improves the linearity of the pressing mechanism's movement, ensuring that the airtight pressure head 36 can vertically and uniformly press the oil seal sealing surface, avoiding misjudgment of local leakage or wear of the sealing ring due to tilting.

[0048] Preferably, a connecting shaft 55 is fixedly provided on the lower connecting plate 54, and a tapered portion 56 is provided at the end of the connecting shaft 55. A buffer spring 57 is sleeved on the connecting shaft 55. The mounting base 34 includes an upper base 58 sleeved on the connecting shaft 55 and a lower base 59 connected to the upper base 58 by bolts. The through hole is provided on the lower base 59. The bottom of the upper base 58 abuts against the tapered portion 56, and the top of the upper base 58 abuts against the buffer spring 57.

[0049] The purpose of this design is to provide contact cushioning and minor adaptive adjustment capabilities while ensuring pressing rigidity, protecting both the equipment and the workpiece. The tapered portion 56 at the end of the connecting shaft 55 mates with the tapered hole at the bottom of the upper body 58, achieving initial precise alignment. A buffer spring 57 is pre-compressed between the connecting shaft 55 and the top of the upper body 58. When the pressure head contacts the workpiece, the spring absorbs some of the impact energy, achieving flexible contact. In the final pressed state, a rigid connection is still formed through the tapered surface fit and bolt locking to ensure a seal. This design balances the compliance of the pressing process with the stability of the operating state, making it particularly suitable for applications requiring high positioning accuracy and component lifespan.

[0050] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A device for testing the airtightness of an oil seal in an electric vehicle drive motor, characterized in that: The system includes a frame and a conveying module and an airtightness testing module housed within the frame. The conveying module includes a roller conveyor line running through the frame. The roller conveyor includes two rows of short rollers and an empty area between the two rows. A motor-supporting assembly and a lifting and limiting assembly located below the motor-supporting assembly are installed in the empty area. The motor-supporting assembly includes a tray and positioning posts and clamps fixedly mounted on the tray. The lifting and limiting assembly includes a support plate, a lifting cylinder, a top plate, multiple reaction support units mounted on the support plate, and blocking cylinders at both ends of the support plate to block the tray. The support plate is fixedly mounted on the frame of the roller conveyor line. The cylinder is fixedly mounted at the center of the support plate. The piston rod of the lifting cylinder is fixedly connected to the top plate. Multiple guide assemblies consisting of first linear bearings and first guide rods are provided between the top plate and the support plate. A fixing block is fixedly mounted below each positioning post on the bottom of the top plate. A reaction support unit is located below each fixing block. The reaction support unit includes a reaction support cylinder, a limiting groove, and a limiting block slidably mounted in the limiting groove. The piston rod of the reaction support cylinder is fixedly connected to the limiting block. The roller conveyor line is also equipped with an infeed photoelectric sensor and an outfeed photoelectric sensor capable of detecting the drive motor. The airtightness detection module includes components located above the conveying module. An airtightness testing frame is provided, comprising an airtightness tester, an airtightness pressing module, and an automatic inspection module. An air storage tank connected to the airtightness tester is housed within the frame. The airtightness pressing module includes a fixed base plate, a slide rail mounted on the fixed base plate, a mounting plate slidably connected to the slide rail via a slider, and a pressing cylinder mounted upside down on the mounting plate. A transverse cylinder connected to the mounting plate is mounted on the fixed base plate. The transverse cylinder pulls the mounting plate along the slide rail via a piston rod. A slotted groove is provided on the fixed base plate. The piston rod of the pressing cylinder passes through the mounting plate and the slotted groove. A mounting base is fixedly connected to the end of the piston rod. An airtightness pressure head is connected to the mounting base via a pin. The automatic inspection component includes a self-inspection fixture buffer station set on the top of the airtightness test frame and a self-inspection station fixed below the fixed base plate by several connecting rods. The self-inspection fixture buffer station includes several oil seal fixtures to be tested and a zero-leakage comparison fixture placed on the placement plate. The self-inspection station includes a self-inspection base plate fixedly connected to the several connecting rods. The oil seal fixtures to be tested or the zero-leakage comparison fixture are detachably connected to the self-inspection base plate by screws. During testing, the transverse cylinder can drive the airtightness pressing module to move along the slide rail and the strip groove to the self-inspection station. The pressing cylinder drives the airtightness pressure head to press down on the oil seal fixtures to be tested or the zero-leakage comparison fixture on the self-inspection base plate to perform a sealing test.During operation, the drive motor is mounted on the tray, which moves with the roller conveyor. After the feed photoelectric sensor detects the drive motor, the roller conveyor stops conveying the tray below the airtight pressing module. At this point, the blocking cylinder holds the tray in place, and the lifting cylinder lifts the tray by moving the top plate. The reaction support cylinder moves the limit block to directly below the fixed block at the bottom of the top plate. Then, the lifting cylinder lowers the top plate and tray, and the fixed block falls onto the limit block. At this point, the support plate replaces the lifting cylinder to provide force support. The pressing cylinder of the airtight pressing module lowers the airtight pressure head to the oil seal of the drive motor. The sealing cavity of the oil seal is inflated and an airtightness test is performed. After the test, the pressing cylinder retracts the airtight pressure head, and the lifting cylinder again lifts the tray by moving the top plate. At this point, the reaction support cylinder moves the limit block away from directly below the fixed block. Then, the lifting cylinder lowers the top plate and tray, the blocking cylinder retracts, and the roller conveyor moves the tray out of the equipment.

2. The oil seal airtightness testing device for an electric vehicle drive motor according to claim 1, characterized in that: Each short roller conveyor is equipped with a baffle on its outer side, and the side of the tray is equipped with rollers that contact the baffle.

3. The oil seal airtightness testing device for an electric vehicle drive motor according to claim 1, characterized in that: The airtightness meter is connected to a standard tank.

4. The oil seal airtightness testing device for an electric vehicle drive motor according to claim 1, characterized in that: Each of the several oil seal fixtures to be tested and the zero-leakage fixture is provided with a foolproof hole at both ends.

5. The oil seal airtightness testing device for an electric vehicle drive motor according to claim 1, characterized in that: The mounting base has a bottom hole, and the airtight pressure head includes a protrusion that can be inserted into the bottom hole. A through hole is provided through the bottom hole, and a mating hole that can communicate with the through hole is provided through the protrusion. The pin can enter from the through hole and be inserted into the mating hole. Both the bottom hole and the protrusion are waist-shaped.

6. The oil seal airtightness testing device for an electric vehicle drive motor according to claim 5, characterized in that: The mounting plate is provided with a linear auxiliary component, which includes a plurality of second linear bearings mounted on the mounting plate, a plurality of second guide rods inserted in the plurality of second linear bearings, and an upper connecting plate and a lower connecting plate that fix the upper and lower ends of the plurality of second guide rods. The end of the piston rod of the pressing cylinder is fixed on the lower connecting plate.

7. The oil seal airtightness testing device for an electric vehicle drive motor according to claim 6, characterized in that: A connecting shaft is fixedly installed on the lower connecting plate. The end of the connecting shaft is provided with a tapered part. A buffer spring is sleeved on the connecting shaft. The mounting base includes an upper seat body sleeved on the connecting shaft and a lower seat body connected to the upper seat body by bolts. The through hole is provided on the lower seat body. The bottom of the upper seat body abuts against the tapered part, and the top of the upper seat body abuts against the buffer spring.

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