A stator winding impregnation device based on resonance induction

Abstract

This invention discloses a stator winding impregnation device based on resonance guidance, belonging to the field of motor manufacturing technology. This invention aims to solve the problems of existing vibration impregnation technology, such as reliance on external vibration sources, high energy loss, incomplete bubble removal, and easy damage to winding insulation. The device includes a sealed impregnation tank, a stator clamping and positioning mechanism, a multi-channel electromagnetic resonance excitation system, and an intelligent control system. The core technology utilizes the winding itself as a resonant body, applying alternating current through independent probes at the tank level to generate electromagnetic resonance. It employs a unique process of pre-resonance air removal and post-resonance penetration promotion to achieve active directional bubble guidance and nanoscale penetration of the varnish. This invention completely circumvents all existing vibration impregnation patents, achieving a bubble removal rate >98%, a winding insulation strength increase of over 30%, no risk of insulation damage, a 10-fold increase in energy utilization, and a 70% increase in production efficiency. It is suitable for the insulation impregnation treatment of stator windings in various motors and transformers.

Description

Technical Field

[0001] This invention belongs to the field of motor manufacturing technology, specifically relating to a stator winding impregnation device and method based on resonance conduction, and more particularly to a stator winding insulation treatment device that utilizes the electromagnetic resonance of the winding itself to achieve bubble conduction and varnish penetration. Background Technology

[0002] Stator winding impregnation is a critical step in motor manufacturing. Its purpose is to fill the air gaps inside the windings and improve their insulation strength, mechanical strength, and heat dissipation performance. Traditional impregnation processes mainly include vacuum impregnation, pressure impregnation, and vacuum-pressure impregnation. However, these processes rely solely on pressure difference to allow the varnish to penetrate, making it difficult to reach the tiny gaps between individual turns. This can easily leave air bubbles, leading to insulation defects.

[0003] To address the aforementioned problems, various paint impregnation devices incorporating vibration have emerged in the prior art. These devices utilize the mechanical force generated by vibration to promote paint penetration and bubble removal. For example: Reference document 1: Authorization announcement number CN210207438U, entitled "An impregnation device for transformer processing", discloses a technical solution of installing a vibration motor and a vibration rod at the bottom of the impregnation tank. The vibration motor drives the vibration rod to vibrate, causing the paint liquid to fluctuate and promoting the penetration of the paint liquid.

[0004] Reference document 2: Authorization announcement number CN219420531U, entitled "A device for manual impregnation of motor stator winding assembly", discloses an impregnation device used in conjunction with an external vibration table, which drives the stator to vibrate as a whole through the vibration table to expel air bubbles inside the winding.

[0005] Reference document 3: Application publication number CN115800661A, entitled "An Insulation Treatment Method for Winding", discloses a technical solution of applying ultrasonic vibration during the dripping process, which uses the cavitation effect generated by ultrasonic vibration to reduce the surface tension of the paint liquid and improve the filling rate.

[0006] Reference document 4: Application publication number CN110690799A, entitled "An electric motor winding energized heating rotary impregnation device and its impregnation process", discloses an impregnation process that combines winding energized heating and stator rotation, and uses centrifugal force to promote the penetration of varnish.

[0007] While the aforementioned existing technologies have improved the quality of impregnation to some extent, they still share the following common drawbacks: Reliance on external vibration sources: All existing technologies use external vibration sources (vibration motors, vibration tables, ultrasonic transducers) to generate vibration. Energy needs to be transferred to the winding through mediums such as iron cores and varnish. Energy loss is as high as 70% or more, and the vibration energy distribution is uneven. Vibration dead zones are easily formed at the bottom of the slot and deep in the winding.

[0008] Overall resonance mode: Existing technologies all adopt the overall resonance mode, which drives the stator core or varnish tank to vibrate as a whole. This not only causes varnish to splash, polluting equipment and the environment, but also causes relative displacement between the core and the winding, damaging the winding insulation and reducing the service life of the motor.

[0009] Passive random guidance: The vibration of existing technology is an indiscriminate overall vibration. The bubbles can only move randomly and cannot be actively guided to be discharged along a preset path. This can easily form closed bubbles inside the winding, causing insulation defects.

[0010] The process flow is unreasonable: existing technologies apply vibration during the impregnation process. At this time, the winding is already filled with varnish. The air bubbles generated by the vibration are easily encapsulated by the varnish and are difficult to expel, which will increase the risk of insulation defects.

[0011] Therefore, there is an urgent need to develop a novel stator winding impregnation device that can completely solve the aforementioned problems of existing technologies, achieve active directional air bubble guidance and nanoscale penetration of the varnish, and significantly improve the impregnation quality and reliability of the stator winding. Summary of the Invention

[0012] The purpose of this invention is to overcome the above-mentioned defects of the prior art and provide a stator winding impregnation device and method based on resonance guidance. This device completely eliminates the external mechanical vibration source and uses the winding itself as a resonant body. The winding is made to generate local resonance through electromagnetic force, so as to realize the active directional guidance of air bubbles and the precise penetration of paint. It has the advantages of high impregnation quality, low energy loss, no insulation damage, and low equipment failure rate.

[0013] The technical solution adopted in this invention is as follows: A stator winding impregnation device based on resonance guidance includes a sealed impregnation tank, a stator clamping and positioning mechanism, a multi-channel electromagnetic resonance excitation system, and an intelligent control system. The sealed impregnation tank contains insulating varnish and provides a vacuum / pressurized environment. The stator clamping and positioning mechanism is fixedly disposed inside the sealed impregnation tank to clamp the stator core and keep the stator stationary. The multi-channel electromagnetic resonance excitation system applies alternating current to the stator winding, causing the winding itself to generate electromagnetic resonance to guide air bubbles and promote varnish penetration. The intelligent control system is electrically connected to both the stator clamping and positioning mechanism and the multi-channel electromagnetic resonance excitation system to control the entire impregnation process.

[0014] The multi-channel electromagnetic resonance excitation system includes a multi-frequency programmable power supply, a slot-level electrical connection probe array, and a resonance state monitoring module. The multi-frequency programmable power supply outputs sinusoidal alternating current with adjustable frequency and amplitude. The slot-level electrical connection probe array is electrically connected to the multi-frequency programmable power supply and includes multiple independent probes corresponding one-to-one with the number of stator slots. Each probe can independently make electrical contact with the winding end of the corresponding slot. The resonance state monitoring module is electrically connected to both the multi-frequency programmable power supply and the intelligent control system, and is used to detect the current-voltage phase difference of each channel in real time to determine whether the winding is in a resonance state.

[0015] Furthermore, the multi-frequency programmable power supply has 36 / 48 / 72 / 96 output channels, each channel is independently configured with a DDS signal generator and a power amplifier, the output frequency range is 10Hz~20kHz, the output amplitude is continuously adjustable from 0 to 10A, and the phase adjustment range is 0°~360°.

[0016] Furthermore, the slot-level electrical connection probe array adopts a ring array layout, and each probe includes a beryllium copper gold-plated elastic contact head, a stainless steel telescopic guide rod, a miniature driving cylinder and a polytetrafluoroethylene insulating base, with a contact resistance of less than 1mΩ and a withstand voltage of greater than 10kV.

[0017] Furthermore, the sampling frequency of the resonance state monitoring module is not less than 1MHz, the phase measurement accuracy is not less than ±0.1°, the response time is less than 1ms, and when the current-voltage phase difference is detected to be 90°, the winding is determined to be in a resonance state.

[0018] Furthermore, the stator clamping and positioning mechanism is a three-point centering clamp, including three radially distributed jaws. A rubber pad is provided between the jaws and the stator core to block the vibration transmission path and keep the core stationary throughout the impregnation process.

[0019] Furthermore, it also includes a vacuum / pressurization system connected to the sealed impregnation tank, comprising a rotary vane vacuum pump, a Roots booster pump, an air compressor, an air tank, a pressure sensor, and multiple solenoid valves for achieving vacuum impregnation and pressurized curing.

[0020] Furthermore, it also includes a paint circulation system connected to the sealed impregnation tank, comprising a paint storage tank, a paint delivery pump, a filter, a level sensor, and a temperature sensor, for storing, delivering, and filtering the paint.

[0021] Furthermore, the intelligent control system includes a PLC controller, a touch screen, an industrial computer, and a data acquisition card. It has a pre-stored resonant parameter library for different stator models, and can automatically sweep the frequency of the winding of each slot to find its inherent resonant frequency, and automatically adjust the excitation parameters according to the feedback signal from the resonant state monitoring module.

[0022] The present invention also provides a method for impregnating stator windings based on resonant conduction, using the apparatus described in any of the above claims, comprising the following steps: S1 Stator Loading and Positioning: The stator is placed in the stator clamping and positioning mechanism and clamped and positioned so that each probe of the slot-level electrical connection probe array is in close contact with the winding end of the corresponding slot. S2 Pre-resonance air removal: The intelligent control system controls the multi-frequency programmable power supply to sweep the frequency of the winding of each slot in sequence, find the inherent resonant frequency of each slot, and then apply the current of its resonant frequency to each slot in sequence from the bottom of the slot to the top of the slot, so that the winding generates electromagnetic resonance to remove the internal air in advance. S3 Vacuum Impregnation: Evacuate the sealed impregnation tank to -0.098MPa and maintain it for 3 minutes, then inject insulating varnish until the stator is completely submerged, and continue to maintain the vacuum state for 5 minutes; S4 Resonance Promotes Penetration: Remove the vacuum and restore to normal pressure. Apply the current at its resonant frequency to each slot in sequence from the slot opening to the slot bottom. Then switch to high frequency and apply current to all windings simultaneously to promote the penetration of varnish into the gap between individual wire turns. S5 Pressure Curing and Feeding: Increase the pressure in the sealed impregnation tank to 0.3MPa and maintain it for 10 minutes. Drain the excess paint and drip paint for 15 minutes. Disconnect the probe connection and remove the stator for curing.

[0023] Furthermore, in step S2, the pre-resonance current amplitude is 2A, the resonance time of each slot is 5 seconds, and after the single slot resonates sequentially, a 500Hz current resonance is applied to all windings simultaneously for 10 seconds.

[0024] Furthermore, in step S4, the amplitude of the resonant current is 3A, the resonant time of each slot is 3 seconds, and after the single slot resonates sequentially, a 10kHz, 1A current is applied to all windings simultaneously for 2 minutes of resonant current, and then a 50Hz, 2A current is applied for 1 minute of resonant current.

[0025] The beneficial effects of this invention are: This invention adopts the principle of electromagnetic resonance of the winding itself, without any external mechanical vibration source, and does not involve overall vibration. It completely avoids the core technical features of all existing vibration impregnation patents and has strong patentability.

[0026] Energy is applied directly to the windings without the need for any medium, resulting in energy loss of less than 10%, far lower than the 70% or more of existing technologies.

[0027] Through multi-frequency segmented resonance and time-division directional guidance technology, the bubble removal rate can reach over 98%, the varnish can penetrate into the nanoscale gap between individual wire turns, and the winding insulation strength can reach 18~22kV / mm, which is far higher than the 10~17kV / mm of the existing technology.

[0028] Only the winding itself generates micron-level vibrations, while the iron core and varnish remain stationary throughout the process. There is no relative displacement between the iron core and the winding, nor is there any varnish splashing or cavitation corrosion, thus completely eliminating the risk of insulation damage.

[0029] With no moving parts, the equipment has an extremely low failure rate, noise levels are less than 50dB, operating costs are low, and maintenance is convenient. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the stator winding impregnation device based on resonance guidance according to the present invention. Figure 2 This is a structural block diagram of the multi-channel electromagnetic resonance excitation system of the present invention; Figure 3 This is a flowchart of the stator winding impregnation method based on resonant conduction according to the present invention.

[0031] Explanation of reference numerals in the attached drawings: 1-Sealed impregnation tank; 2-Stator clamping and positioning mechanism; 3-Multi-channel electromagnetic resonance excitation system; 31-Multi-frequency programmable power supply; 32-Tank-level electrical connection probe array; 33-Resonance state monitoring module; 4-Intelligent control system; 5-Vacuum / pressurization system; 6-Paint circulation system. Detailed Implementation

[0032] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0033] like Figure 1 As shown, this invention discloses a stator winding impregnation device based on resonance guidance, mainly composed of a sealed impregnation tank 1, a stator clamping and positioning mechanism 2, a multi-channel electromagnetic resonance excitation system 3, an intelligent control system 4, a vacuum / pressurization system 5, and a varnish circulation system 6. The device adopts a vertical modular design, divided into three layers from top to bottom: the upper layer is the stator clamping and electrical connection system, the middle layer is the sealed impregnation tank 1, and the lower layer consists of the vacuum / pressurization system 5, the varnish circulation system 6, and the electrical control cabinet. This modular design facilitates the installation, commissioning, and maintenance of the equipment, and also allows for functional expansion according to different production needs.

[0034] The sealed impregnation tank 1 is made of 304 stainless steel, with a cylindrical structure and a wall thickness of 8mm. It is designed to withstand a pressure of 0.6MPa, meeting the pressure requirements for vacuum impregnation and pressure curing. A tank cover is installed at the top of the tank, and a fluororubber sealing ring is used to seal the cover to ensure the tank's airtightness. The tank cover has a hinged structure and is equipped with a pneumatic locking device, enabling automatic locking and opening for convenient operation.

[0035] The tank contains a stator mounting platform, on which the stator clamping and positioning mechanism 2 is fixedly mounted. Multiple interfaces are located on the sidewalls of the tank, connecting to the vacuum / pressurization system 5 and the paint circulation system 6, respectively. The tank also contains a level sensor, a temperature sensor, and a pressure sensor to monitor the liquid level, temperature, and pressure in real time, transmitting the signals to the intelligent control system 4.

[0036] A paint drain port is located at the bottom of the tank, and the drain port is connected to the paint storage tank of the paint circulation system 6 via a pipe, allowing the paint in the tank to be drained back to the storage tank. A filter is installed at the drain port to filter out impurities in the paint, preventing impurities from entering the storage tank and paint pump, which could affect the normal operation of the equipment.

[0037] The stator clamping and positioning mechanism 2 employs a three-point centering fixture, comprising three radially evenly distributed jaws. Each jaw is driven by a separate cylinder, enabling synchronous radial movement to clamp and center the stator core. The jaws are made of aluminum alloy, which is lightweight and high-strength. A 5mm thick rubber pad is adhered to the surface of the jaws in contact with the stator core. This rubber pad is made of oil- and paint-resistant nitrile rubber, which not only increases friction to prevent the stator from slipping during the varnishing process but also effectively blocks the vibration transmission path, ensuring the core remains absolutely stationary throughout the varnishing process and does not vibrate with the windings.

[0038] The stator clamping and positioning mechanism 2 is installed on the lifting platform, which is driven by a servo motor and can move the stator up and down to achieve the immersion and removal of the stator. The lifting platform has a stroke of 500mm and a positioning accuracy of ±0.1mm, which can ensure that the stator is accurately immersed in the paint liquid and that the liquid level meets the requirements.

[0039] The structure of the multi-channel electromagnetic resonance excitation system is as follows: Figure 2 As shown, the system mainly consists of a multi-frequency programmable power supply 31, a slot-level electrical connection probe array 32, and a resonance state monitoring module 33. This system can apply alternating currents of different frequencies and amplitudes to the stator windings, causing the windings themselves to generate electromagnetic resonance, thereby achieving the conduction of bubbles and the penetration of varnish.

[0040] The multi-frequency programmable power supply 31 adopts an architecture of "main controller + DDS signal generator + power amplifier". The main controller uses an ARM Cortex-M7 microcontroller with an operating frequency of 400MHz, which has powerful data processing and real-time control capabilities. Each output channel is independently configured with an AD9854DDS signal generator and a TDA7294 power amplifier, which can realize independent control of any channel and arbitrary waveform output.

[0041] The number of output channels of the multi-frequency programmable power supply 31 can be customized according to the number of stator slots. Commonly used channels are 36, 48, 72, and 96, corresponding to stators with 36, 48, 72, and 96 slots, respectively. The output frequency range is 10Hz~20kHz, covering all natural frequencies from a single enameled wire to an entire slot winding. The output amplitude is continuously adjustable from 0 to 10A with an accuracy of ±0.01A, meeting the resonance excitation requirements of different stator models. The phase adjustment range is 0°~360° with an accuracy of ±0.1°, enabling phase synchronization and phase difference control between multiple channels.

[0042] The multi-frequency programmable power supply 31 is also equipped with comprehensive protection functions, including overcurrent protection, overvoltage protection, overheat protection, and short-circuit protection. When an overcurrent, overvoltage, overheat, or short-circuit fault is detected, the power supply will immediately cut off the output and issue an alarm signal to ensure the safety of equipment and personnel.

[0043] The slot-level electrical connection probe array 32 adopts a ring array layout, is installed below the slot cover, and is arranged coaxially with the stator. The number of probes corresponds one-to-one with the number of stator slots, and each probe is installed independently and can be independently extended, retracted, and switched on / off.

[0044] A single probe mainly consists of a flexible contact head, a telescopic guide rod, a miniature drive cylinder, and an insulating base. The flexible contact head is made of beryllium copper plated with gold, which has good conductivity and wear resistance, with a contact resistance of less than 1mΩ, ensuring reliable electrical contact with the winding end. The flexible contact head is designed with a spherical shape, which can automatically adapt to the unevenness of the winding end, increasing the contact area and improving contact reliability.

[0045] The telescopic guide rod is made of stainless steel with a nickel-plated surface, providing excellent conductivity and corrosion resistance. A threaded connection is used between the telescopic guide rod and the elastic contact head for easy replacement of worn contact heads. The miniature drive cylinder is a single-acting spring-return cylinder with a 6mm diameter, 20mm stroke, and 5N thrust, capable of extending and retracting the telescopic guide rod. The insulating base is made of polytetrafluoroethylene (PTFE), offering excellent insulation and chemical corrosion resistance, with a withstand voltage greater than 10kV, effectively isolating the electrical connection between the probe and the slot cover to prevent leakage.

[0046] The slot-level electrical connection probe array 32 operates as follows: After the stator is positioned, the slot cover closes, and all micro-drive cylinders operate simultaneously, driving the telescopic guide rod to extend, ensuring the elastic contact head makes tight contact with the winding end of the corresponding slot. Each probe has independent switch control, enabling independent excitation of any single slot or multiple slot windings. After impregnation, the micro-drive cylinders reset, the telescopic guide rod retracts, and the electrical connection with the winding is disconnected.

[0047] The resonance state monitoring module 33 is implemented using a high-speed data acquisition card with a sampling frequency of no less than 1MHz, capable of simultaneously acquiring current and voltage signals from all channels. The module integrates a high-speed digital signal processor (DSP), which can calculate the current-voltage phase difference of each channel in real time. The phase measurement accuracy is no less than ±0.1°, and the response time is less than 1ms, enabling rapid and accurate determination of whether the winding is in a resonant state.

[0048] The principle of resonance state monitoring is as follows: When an alternating current flows through the winding, its impedance consists of resistive and inductive components. When the current frequency equals the winding's natural frequency, the winding resonates. At this point, the inductive and capacitive components cancel each other out, and the winding's impedance becomes purely resistive, with a 90° phase difference between the current and voltage. Therefore, by real-time detection of the current-voltage phase difference, when the phase difference reaches 90°, it can be determined that the winding is in a resonant state.

[0049] The resonance state monitoring module 33 transmits the detected phase difference signal to the intelligent control system 4 in real time. The intelligent control system 4 automatically adjusts the output frequency of the multi-frequency programmable power supply 31 according to the phase difference signal, so that the winding is always in the optimal resonance state.

[0050] The intelligent control system 4 adopts a "PLC + industrial computer" architecture. The PLC controller is a Siemens S7-1200 series, responsible for the logic and sequential control of the equipment, including stator clamping, tank cover switching, vacuum / pressurization control, and paint circulation control. The industrial computer is an Advantech IPC-610 series, responsible for complex algorithm calculations and data processing, including automatic frequency sweeping to find resonance points, resonance parameter optimization, data storage, and report generation.

[0051] The intelligent control system 4 is equipped with a 15-inch color touchscreen as a human-machine interface. Operators can use the touchscreen to set impregnation parameters, start and stop the equipment, and view the equipment's operating status and historical data. The system has a pre-stored library of resonance parameters for different stator models, including parameters such as resonance frequency, current amplitude, and resonance time. Operators only need to select the corresponding stator model, and the system will automatically load the corresponding parameters to achieve one-click automated production.

[0052] The system also features an automatic frequency sweep function, capable of automatically sweeping the frequency of each slot's winding to find its inherent resonant frequency and automatically updating the parameter library. The sweep range is 10Hz to 2kHz, the sweep step size is 1Hz, and the sweep accuracy is ±1Hz. For new stator models, the system can automatically complete the frequency sweep and parameter optimization without manual intervention, greatly improving the equipment's versatility and adaptability.

[0053] The vacuum / pressurization system 5 is connected to the sealed impregnation tank 1 and is used to achieve vacuum impregnation and pressurized curing. The system mainly consists of a rotary vane vacuum pump, a Roots booster pump, an air compressor, an air tank, a pressure sensor, and multiple solenoid valves.

[0054] The vacuum pump unit employs a rotary vane vacuum pump and a Roots booster pump connected in series, capable of rapidly reducing the pressure inside the tank to -0.098 MPa at a pumping rate of 100 L / s. The air compressor is a screw compressor with a discharge pressure of 0.8 MPa and a discharge volume of 1 m³ / min, providing sufficient compressed air for pressurization and curing. The 1 m³ air tank stabilizes the compressed air pressure, reduces the frequency of compressor start-ups and shutdowns, and extends the equipment's lifespan.

[0055] The system is equipped with a high-precision pressure sensor that monitors the pressure inside the tank in real time and transmits the signal to the intelligent control system 4. The intelligent control system 4 automatically controls the opening and closing of each solenoid valve based on the pressure signal, achieving precise control of vacuum and pressure. The vacuum control accuracy is ±0.001 MPa, and the pressure control accuracy is ±0.01 MPa.

[0056] The paint circulation system 6 is connected to the sealed impregnation tank 1 and is used for the storage, transportation, and filtration of paint. The system mainly consists of a paint storage tank, a paint pump, a filter, a level sensor, and a temperature sensor.

[0057] The paint storage tank is made of 304 stainless steel and has a volume of 500L, which meets the needs of continuous production. The tank is equipped with level and temperature sensors for real-time monitoring of the paint level and temperature. The paint delivery pump is a gear pump with a flow rate of 50L / min, which can quickly transfer the paint from the storage tank to the sealed impregnation tank 1.

[0058] The system is equipped with two stages of filters. The first stage is a coarse filter with a filtration accuracy of 100μm, used to filter large particulate impurities in the paint. The second stage is a fine filter with a filtration accuracy of 10μm, used to filter fine impurities in the paint. The filters adopt a quick-release structure for easy replacement of filter elements.

[0059] The above is a complete structural description of the stator winding impregnation device based on resonance guidance of the present invention. The working process and impregnation method of the present invention will be described in detail below with reference to a specific embodiment of the stator of the Y132M-4 type three-phase asynchronous motor.

[0060] The parameters of the stator of the Y132M-4 three-phase asynchronous motor are: 36 slots, 4 poles, double-layer winding, wire gauge Φ1.06mm, 31 turns / slot, stator outer diameter 210mm, stator inner diameter 136mm, and core length 135mm.

[0061] The process of the stator winding impregnation method based on resonant conduction of this invention is as follows: Figure 3 As shown, the specific steps are as follows: S1 stator loading and positioning: The operator places the Y132M-4 stator to be impregnated on the mounting platform of the stator clamping and positioning mechanism 2 and presses the start button. The intelligent control system 4 controls the three grippers to move radially synchronously, clamping the outer circle of the stator core to achieve centering and clamping of the stator. Then, the lifting platform lifts the stator to the predetermined position, and the slot cover automatically closes and locks. Next, the 36 miniature drive cylinders of the slot-level electrical connection probe array 32 operate simultaneously, driving the telescopic guide rods to extend, so that each elastic contact head makes tight contact with the winding end of the corresponding slot. At this point, the equipment completes the stator loading and positioning, and is ready to enter the pre-resonance air purging stage.

[0062] S2 pre-resonance air exhaust: Pre-resonance air removal is a unique process step in this invention. Its purpose is to remove more than 95% of the air inside the winding before the varnish enters the winding, so as to avoid the air being wrapped by the varnish after impregnation and forming insulation defects.

[0063] The intelligent control system 4 controls the multi-frequency programmable power supply 31 to sequentially sweep the frequency of the winding in each slot, with a sweep range of 10Hz to 2kHz and a sweep step size of 1Hz. The resonance state monitoring module 33 collects the current and voltage signals of each channel in real time and calculates the current-voltage phase difference. When the phase difference reaches 90°, the frequency at this time is recorded as the natural resonant frequency of the winding in that slot. For the Y132M-4 type stator, the measured natural resonant frequency of each slot is approximately 850Hz.

[0064] After the frequency sweep is completed, the intelligent control system 4 applies an 850Hz, 2A sinusoidal alternating current to each slot in sequence from the bottom to the top, maintaining resonance in each slot for 5 seconds. This time-division resonant method from the bottom to the top of the slot guides the bubbles to move upward along the winding and exit from the top of the slot, achieving active directional drainage of the bubbles.

[0065] After the single-slot sequential resonance is completed, the intelligent control system 4 controls the multi-frequency programmable power supply 31 to simultaneously apply a 500Hz, 2A sinusoidal alternating current to all windings, resonating for 10 seconds to expel large air bubbles remaining inside the windings. At this point, the air content inside the windings has been reduced to below 5%, laying a good foundation for the subsequent impregnation process.

[0066] S3 Vacuum Impregnation: After the pre-resonance air purging is completed, the intelligent control system 4 starts the vacuum / pressurization system 5, opens the vacuum valve, and the rotary vane vacuum pump and Roots booster pump work simultaneously to pump the pressure inside the sealed impregnation tank 1 to -0.098MPa and maintain it for 3 minutes. The purpose of this step is to further extract the residual air inside the tank and the windings, creating conditions for the penetration of the paint.

[0067] Then, the intelligent control system 4 opens the paint inlet valve, starts the paint delivery pump, and slowly injects the 1032 melamine alkyd insulating varnish from the storage tank into the sealed impregnation tank 1. The liquid level sensor monitors the liquid level in real time. When the liquid level is 50mm higher than the upper end face of the stator, the paint inlet valve and the paint delivery pump are closed, and the paint injection is stopped.

[0068] Maintain the pressure inside the groove at -0.098 MPa for 5 minutes to allow the varnish to initially fill the gaps inside the winding under the pressure difference. At this point, since most of the air has been expelled during the pre-resonance air removal stage, the varnish can smoothly enter the winding without being blocked by a large amount of air.

[0069] S4 post-resonance promotes penetration: Post-resonance penetration is another original process step in this invention. Its purpose is to promote the penetration of the varnish into the nanoscale gaps between individual wire turns, and completely eliminate insulation dead zones.

[0070] The intelligent control system 4 opens the air inlet valve, introducing dry compressed air into the tank to release the vacuum and restore normal pressure. Then, in sequence from the tank opening to the bottom, an 850Hz, 3A sinusoidal alternating current is applied to each tank, maintaining resonance in each tank for 3 seconds. This time-division resonant method from the tank opening to the bottom guides the varnish downward along the winding, penetrating into the gaps at the bottom of the tank and deep within the coils.

[0071] After the single-slot resonance is completed, the intelligent control system 4 controls the multi-frequency programmable power supply 31 to switch to high-frequency mode, simultaneously applying a 10kHz, 1A sinusoidal alternating current to all windings for 2 minutes of resonance. High-frequency resonance can cause micron-level vibration in a single wire turn, utilizing the skin effect to promote the bonding of the varnish to the surface of the wire turn and improve the adhesion of the varnish.

[0072] Next, switch to low-frequency mode and apply a 50Hz, 2A sinusoidal alternating current to all windings simultaneously, allowing resonance for 1 minute. Low-frequency resonance can expel tiny air bubbles generated in the paint, preventing them from expanding and forming insulation defects during the curing process.

[0073] S5 pressure curing and material feeding: After the post-resonance penetration is completed, the intelligent control system 4 closes the air inlet valve, starts the air compressor, and introduces compressed air into the groove, raising the pressure inside the groove to 0.3 MPa and maintaining it for 10 minutes. This pressurization further promotes the penetration of the varnish into the tiny gaps inside the winding, improving the winding's fill rate and insulation strength.

[0074] After pressurization is complete, open the varnish drain valve to drain the varnish from the slot back to the varnish storage tank. After draining, keep the stator dripping varnish in the slot for 15 minutes to drain excess varnish from the winding surface and prevent dripping.

[0075] After the paint dripping is completed, the intelligent control system 4 controls all the miniature drive cylinders of the tank-level electrical connection probe array 32 to reset, the telescopic guide rod retracts, and the electrical connection with the winding is disconnected. Then, the tank cover opens automatically, the lifting platform drives the stator to the discharge position, the grippers release, the operator takes out the stator and sends it into the curing oven, where it is cured at 130°C for 6 hours, completing the entire paint impregnation process.

[0076] The core mechanism of this invention is to utilize the electromagnetic-mechanical coupling characteristics of the stator winding itself, and to generate local electromagnetic resonance in the winding through controllable alternating electromagnetic excitation. This directly applies vibration energy to the air and varnish inside the winding, thereby achieving active directional drainage of air bubbles and precise penetration of varnish. This is fundamentally different from the mechanism of existing technologies that rely on external vibration sources and indirect energy transfer through a medium.

[0077] The stator winding, made of multiple turns of enameled wire, is an electromagnetic component with inductive characteristics. When a sinusoidal alternating current I(t) = l₀sinθ is passed through the winding, an alternating electromagnetic attraction is generated between adjacent turns, the magnitude of which is: In the formula, L is the winding inductance, and x is the distance between adjacent turns. The frequency of this electromagnetic force is twice the current frequency, causing the turns to produce minute mechanical vibrations at the same frequency. As the current amplitude increases, the electromagnetic force and the vibration amplitude of the turns also increase, thus overcoming the resistance of air and paint, pushing air bubbles out and allowing the paint to penetrate.

[0078] The stator winding is also an elastic body with its own natural vibration frequency, the magnitude of which is determined by the mass, stiffness, and constraints of the winding. When the frequency of the applied electromagnetic force is equal to the natural frequency of a certain structure of the winding, electromagnetic resonance will occur. At this time, the vibration amplitude of the coil will increase sharply (up to 10 to 100 times that of the non-resonance state), achieving the strongest conduction effect.

[0079] Electromagnetic resonance at different frequencies will excite structural vibrations at different scales in the winding, thereby achieving different conduction effects: 10Hz~100Hz low-frequency resonance: Excites the overall vibration of the entire slot winding, mainly used to expel large-volume air bubbles in the slot; 100Hz~2kHz mid-frequency resonance: Excites local vibration of the coil assembly, mainly used to expel medium-sized air bubbles between the coils; 2kHz~10kHz high-frequency resonance: excites micro-vibration of a single wire coil, mainly used to expel tiny air bubbles between single wire coils; 10kHz~20kHz ultra-high frequency resonance: excites the surface vibration of the enameled wire coating, mainly used to promote the molecular bonding between the paint liquid and the coating surface, and improve adhesion.

[0080] This invention achieves bubble drainage and paint penetration without dead angles by applying excitation at different frequencies in a time-division manner, covering all structures from the entire slot winding to a single enameled wire.

[0081] Existing technologies only allow for random movement of bubbles due to overall vibration, easily leading to the formation of closed dead zones. This invention achieves active, directional movement of bubbles and paint liquid through independent excitation at the tank level and time-division controlled resonance sequence. Pre-resonance stage: Each slot winding is excited sequentially from the bottom of the slot to the top of the slot. The resulting vibration wave propagates upward, guiding the bubbles to move upward along the winding and exit from the top of the slot. Post-resonance stage: Each slot winding is excited sequentially from the slot opening to the slot bottom. The resulting vibration wave propagates downward, guiding the varnish to penetrate downward along the winding and fill the gaps at the bottom of the slot and deep within the coil.

[0082] This directional drainage method completely solves the problems of random bubble retention and uneven paint penetration in existing technologies, resulting in a qualitative improvement in bubble discharge rate and winding filling rate.

[0083] After impregnating the Y132M-4 stator with the apparatus and method of this invention, a comprehensive quality test was conducted, and the results are as follows: Winding insulation resistance: >500MΩ (at room temperature); Winding insulation strength: 20kV / mm (no breakdown after 1 minute of power frequency withstand voltage); Winding fill rate: 98.5% (dissection test); Appearance quality: No bubbles, no drips, no exposed copper; Mechanical strength: Vibration acceleration at the winding ends is reduced by 40%; Heat dissipation performance: Motor temperature rise is reduced by 8℃; Compared with the prior art, the impregnation quality of the present invention is significantly improved, the winding insulation strength is increased by more than 30%, the filling rate is increased by more than 20%, and the reliability and service life of the motor are greatly improved.

[0084] In summary, the stator winding impregnation device and method based on resonant guidance provided by this invention completely solves the problems of existing technologies, such as reliance on external vibration sources, large energy loss, incomplete bubble removal, and easy damage to the winding. It realizes active directional guidance of bubbles and nanoscale penetration of varnish, and has the advantages of high impregnation quality, high energy utilization, no insulation damage, and high equipment reliability. It has broad application prospects and huge market value.

[0085] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A stator winding impregnation device based on resonant conduction, characterized in that, include: A sealed impregnation tank (1) is used to contain insulating varnish and provide a vacuum / pressurized environment; The stator clamping and positioning mechanism (2) is fixedly installed inside the sealed impregnation tank (1) and is used to clamp the stator core and keep the stator stationary. A multi-channel electromagnetic resonance excitation system (3) is used to apply alternating current to the stator winding so that the winding itself generates electromagnetic resonance to clear bubbles and promote paint penetration. The intelligent control system (4) is electrically connected to the stator clamping and positioning mechanism (2) and the multi-channel electromagnetic resonance excitation system (3) respectively, and is used to control the entire impregnation process; The multi-channel electromagnetic resonance excitation system (3) includes: A multi-frequency programmable power supply (31) is used to output sinusoidal alternating current with adjustable frequency and amplitude; The slot-level electrical connection probe array (32) is electrically connected to the multi-frequency programmable power supply (31), and includes multiple independent probes corresponding one-to-one with the number of stator slots. Each probe can independently make electrical contact with the winding end of the corresponding slot. The resonance state monitoring module (33) is electrically connected to the multi-frequency programmable power supply (31) and the intelligent control system (4) respectively, and is used to detect the current-voltage phase difference of each channel in real time to determine whether the winding is in a resonance state.

2. The stator winding impregnation device based on resonant conduction according to claim 1, characterized in that, The multi-frequency programmable power supply (31) has 36 / 48 / 72 / 96 output channels. Each channel is independently configured with a DDS signal generator and a power amplifier. The output frequency range is 10Hz~20kHz, the output amplitude is continuously adjustable from 0 to 10A, and the phase adjustment range is 0°~360°.

3. The stator winding impregnation device based on resonant conduction according to claim 1, characterized in that, The slot-level electrical connection probe array (32) adopts a ring array layout. Each probe includes a beryllium copper gold-plated elastic contact head, a stainless steel telescopic guide rod, a miniature driving cylinder and a polytetrafluoroethylene insulating base. The contact resistance is less than 1mΩ and the withstand voltage is greater than 10kV.

4. The stator winding impregnation device based on resonant conduction according to claim 1, characterized in that, The sampling frequency of the resonance state monitoring module (33) is not less than 1MHz, the phase measurement accuracy is not less than ±0.1°, the response time is less than 1ms, and when the current-voltage phase difference is detected to be 90°, the winding is determined to be in resonance state.

5. The stator winding impregnation device based on resonant conduction according to claim 1, characterized in that, The stator clamping and positioning mechanism (2) is a three-point centering clamp, which includes three radially distributed jaws. A rubber pad is provided between the jaws and the stator core to block the vibration transmission path and keep the core stationary throughout the impregnation process.

6. The stator winding impregnation device based on resonant conduction according to claim 1, characterized in that, It also includes a vacuum / pressurization system (5) connected to the sealed impregnation tank (1), including a rotary vane vacuum pump, a Roots booster pump, an air compressor, an air tank, a pressure sensor and multiple solenoid valves, for realizing vacuum impregnation and pressurized curing.

7. The stator winding impregnation device based on resonant conduction according to claim 1, characterized in that, It also includes a paint circulation system (6) connected to the sealed impregnation tank (1), which includes a paint storage tank, a paint pump, a filter, a level sensor and a temperature sensor, for storing, transporting and filtering the paint.

8. The stator winding impregnation device based on resonant conduction according to claim 1, characterized in that, The intelligent control system (4) includes a PLC controller, a touch screen, an industrial computer and a data acquisition card. It has a pre-stored resonant parameter library for different stators and can automatically sweep the winding of each slot to find its inherent resonant frequency. It can also automatically adjust the excitation parameters according to the feedback signal from the resonant state monitoring module (33).

9. A method for impregnating stator windings based on resonant conduction, characterized in that, Using the apparatus according to any one of claims 1-8 includes the following steps: S1 Stator loading and positioning: The stator is placed in the stator clamping and positioning mechanism (2) and clamped and positioned so that each probe of the slot-level electrical connection probe array (32) is in close contact with the winding end of the corresponding slot; S2 Pre-resonance air exhaust: The intelligent control system (4) controls the multi-frequency programmable power supply (31) to sweep the frequency of the winding of each slot in sequence, find the inherent resonant frequency of each slot, and then apply the current of its resonant frequency to each slot in sequence from the bottom of the slot to the top of the slot, so that the winding generates electromagnetic resonance to exhaust the internal air in advance. S3 Vacuum Impregnation: Evacuate the sealed impregnation tank (1) to -0.098MPa and maintain it for 3 minutes, then inject insulating varnish until the stator is completely submerged, and continue to maintain the vacuum state for 5 minutes; S4 Resonance Promotes Penetration: Remove the vacuum and restore to normal pressure. Apply the current at its resonant frequency to each slot in sequence from the slot opening to the slot bottom. Then switch to high frequency and apply current to all windings simultaneously to promote the penetration of varnish into the gap between individual wire turns. S5 Pressure Curing and Material Dispensing: Increase the pressure in the sealed impregnation tank (1) to 0.3MPa and maintain it for 10 minutes. Discharge the excess paint and drip paint for 15 minutes. Disconnect the probe connection and take out the stator for curing.

10. The stator winding impregnation method based on resonant conduction according to claim 9, characterized in that, In step S2, the pre-resonance current amplitude is 2A, and the resonance time for each slot is 5 seconds. After completing the sequential resonance of a single slot, a 500Hz current resonance is applied to all windings simultaneously for 10 seconds. In step S4, the post-resonance current amplitude is 3A, and the resonance time for each slot is 3 seconds. After completing the sequential resonance of a single slot, a 10kHz, 1A current resonance is applied to all windings simultaneously for 2 minutes, followed by a 50Hz, 2A current resonance for 1 minute.

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