An environment-friendly motor resistant to corona aging and its manufacturing method

Abstract

The present invention provides an environment-friendly motor resistant to corona aging and a manufacturing method thereof. The environment-friendly motor includes: a stator core and a stator winding. The stator core is provided with stator slots for placing the stator winding. The stator core is formed by laminating a plurality of silicon steel sheets. An insulating structure made of recyclable corona-resistant insulating material is arranged in the stator slots. The insulating structure includes: slot insulation and inter-winding insulation. The slot insulation is laid on the inner wall of the stator slots, and the inter-winding insulation is arranged in the space surrounded by the stator slots. In the cross-sectional direction of the stator core, the space surrounded by the stator slots is divided into multiple parts to separate the stator windings wound in the stator slots. The insulating material includes: nano-scale MPIA short fibers and nano-titanium dioxide particles. This environment-friendly motor not only has excellent corona aging resistance but also has the characteristic of being recyclable. The manufacturing process is simple and the recycling path is environmentally friendly, having good application prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of motors, and more specifically, relates to an environmentally friendly motor resistant to corona aging and a manufacturing method thereof. Background Art

[0002] The insulating materials used to manufacture the insulation structure of motors should have good insulation performance and mechanical strength. In the prior art, although the insulating materials have been industrialized, there are still defects such as insufficient insulation strength, short service life, and difficulty in recycling.

[0003] In the prior art, the insulating materials used in motors generally serve in high-voltage environments. In addition to facing the risk of electrical breakdown, the influence of long-term strong electric fields will also cause different degrees of aging on the surface and inside of the materials, mainly in the forms of thermal aging and corona aging. Corona aging will cause the surface of the materials to become powdered and cracked, and the internal structure will also become loose, reducing the insulation strength of the materials and increasing the risk of breakdown.

[0004] Specifically, the influence of corona aging on materials mainly has three aspects: (1) The impact of high-energy particles may break the chemical bonds with relatively low bond energy on the material surface, changing the surface morphology and roughness; (2) Chemical corrosion by active products, such as ozone, etc., can accelerate the deterioration of the insulation surface; (3) Thermal effect, corona discharge will generate a strong thermal effect, continuously thermally age the material, and cause changes in its internal structure.

[0005] At the same time, the application of recyclable materials and the exploration of the recycling path of insulating materials have always been the focus of attention in the industry. In addition to traditional burial and incineration, the main treatment methods for insulating materials are physical recycling and chemical recycling. Physical recycling includes cleaning, crushing, melting, granulation, etc., and its recycling efficiency is low, and it cannot maximize the utilization of aged and scrapped materials. Chemical recycling methods are generally high-temperature degradation under extreme conditions. There is a method in the prior art for recycling insulating substrates with subcritical water and supercritical water, which has extremely high energy consumption and a long recycling period, and cannot achieve large-scale green recycling. Summary of the Invention

[0006] To solve the deficiencies in the prior art, the present invention provides an environmentally friendly motor resistant to corona aging and a manufacturing method thereof. By using an insulation structure with a specific structure and specific materials, the synchronous improvement of insulation performance and environmental protection level is achieved.

[0007] The present invention adopts the following technical solutions.

[0008] The first aspect of the present invention provides an environmentally friendly motor resistant to corona aging, including: a stator core and a stator winding. The stator core is provided with stator slots for placing the stator winding;

[0009] The stator core is made of multiple silicon steel sheets stacked together, and the stator winding is placed in the slots of the stator core.

[0010] An insulation structure made of recyclable anti-corona insulation material is arranged in the stator slot, and the insulation structure includes: slot body insulation and inter-winding insulation, the slot body insulation is laid on the inner wall of the stator slot, and the inter-winding insulation is arranged in the space surrounded by the stator slot, and the space surrounded by the stator slot is divided into multiple parts in the direction of the cross section of the stator core, so as to separate the stator windings wound in the stator slot;

[0011] The insulating material comprises: nano-scale MPIA short fibers and nano-titanium dioxide particles.

[0012] Preferably, the stator slot is a round bottom slot structure, which gradually narrows from the round bottom slot to the slot opening. The slot body insulation is consistent with the shape of the inner wall of the stator slot and extends toward the center of the slot opening at the slot opening. The inter-winding insulation includes a longitudinal beam and a cross beam extending from the longitudinal beam to both sides. The cross beam at the bottom of the slot is arc-shaped and abuts against the slot body insulation at the bottom of the slot. The cross beam at the slot opening closes the slot opening and overlaps with the slot body insulation at the slot opening.

[0013] Preferably, nano-sized MPIA staple fibers and nano-titanium dioxide particles, wherein the nano-sized MPIA staple fibers are prepared by deprotonating the MPIA staple fibers in a DMAc / LiCl system, and have a diameter of 7-10 nanometers;

[0014] The nano-titanium dioxide particles are rutile crystal type, have a particle size of 5-20 nanometers, a mass fraction of 10-20 wt%, and are uniformly distributed in the nano-scale MPIA staple fibers.

[0015] Preferably, the surface of the slot insulation and the inter-winding insulation is smooth and pure white, with a thickness of 0.08-0.20 mm, and the interface is a honeycomb porous structure with a hole diameter of 0.5-1 nm;

[0016] After aging in a strong DC electric field for 20-40 hours, the breakdown field strength and tensile strength of the slot insulation and the insulation between the windings still retain 90-95% of the original state, and the dielectric constant and dielectric loss remain at 94-98% of the existing technical state.

[0017] A second aspect of the present invention provides a method for manufacturing an environmentally friendly motor that is resistant to corona aging, which is used to manufacture the environmentally friendly motor that is resistant to corona aging, comprising the following steps:

[0018] A stator core including a stator slot structure is manufactured using magnetic material;

[0019] An insulating material comprising nano-scale MPIA staple fibers and nano-titanium dioxide particles is prepared, and slot insulation and inter-winding insulation are prepared based on the insulating material;

[0020] Insert the prepared slot insulation into the stator slots, ensuring that the insulation paper completely covers the slot walls and leaving a margin; insert inter-winding insulation between different layers of the winding to prevent inter-layer short circuits;

[0021] Install the rotor core, permanent magnets or windings, conduct a dynamic balance test, and install other accessory structures to complete the general assembly.

[0022] Preferably, the stator core made of magnetic material and including the stator slot structure includes:

[0023] Use a punching machine to blank the silicon steel sheet into an annular shape with a stator slot structure and perform annealing treatment, where the stator slot is a round-bottom slot structure that gradually narrows from the round bottom towards the slot opening;

[0024] Coat a layer of insulating material on the surface of the silicon steel sheet;

[0025] Stack the blanked silicon steel sheets together according to the design requirements; perform turning on the outer circle and inner hole of the stator core and remove the burrs generated during blanking and processing.

[0026] Preferably, the preparation of the insulating material containing nano-scale MPIA short fibers and nano-titanium dioxide particle components and the preparation of slot insulation and inter-winding insulation based on this insulating material include:

[0027] Place the MPIA short fibers in the DMAc / LiCl system to be deprotonated at a set temperature to form an ANF solution;

[0028] Grind the nano-titanium dioxide particles, add the ground particles to the ANF solution and stir mechanically to form an ANF / mixture;

[0029] The obtained ANF / mixture is coated on a film coater with a set coating thickness to form a film;

[0030] The obtained ANF / aerogel is dried at a set drying temperature and drying duration and hot-pressed at a set hot-pressing temperature and hot-pressing pressure and hot-pressing duration to perform hot-pressing;

[0031] The hot-pressed insulating material is cut according to the stator slot type, winding size and insulation requirements of the motor and prepared into slot insulation and inter-winding insulation.

[0032] Preferably, cutting the hot-pressed insulating material according to the stator slot shape, winding size and insulation requirements of the motor, and preparing it into slot insulation and inter-winding insulation includes:

[0033] Preparing the slot insulation to be consistent with the inner wall shape of the stator slot, and at the slot opening, extending towards the center of the slot opening. The inter-winding insulation includes a longitudinal beam and cross beams extending from the longitudinal beam to both sides. The cross beams at the bottom of the slot are arc-shaped and abut against the slot insulation at the bottom of the slot. The cross beams at the slot opening close the slot opening and overlap with the slot insulation at the slot opening.

[0034] Preferably, the deprotonation temperature is 130 - 150 °C, the time is 6 - 10 hours, the concentration of LiCl is 0.02 - 0.04 g / mL, and the concentration of ANF is 0.06 - 0.08 g / mL;

[0035] The nano-titanium dioxide particles are of rutile crystal form, and the particle size of the nano-titanium dioxide is 5 - 20 nanometers, and the mass fraction is 10 - 20 wt%, and the mechanical stirring duration is 0.5 - 1 hour.

[0036] The coating film thickness is 0.8 - 1.2 millimeters, and the size is 10 cm × 15 cm;

[0037] The standing duration in deionized water is 10 - 15 hours;

[0038] The drying temperature is 60 - 100 °C, the drying duration is 0.5 - 1 hour, the hot pressing temperature is 160 - 200 °C, the hot pressing pressure is 15 - 20 MPa, the hot pressing duration is 1 - 2 minutes, and the thickness after hot pressing is 0.08 - 0.2 millimeters.

[0039] Preferably, placing the MPIA staple fibers in a DMAc / LiCl system for deprotonation at a set temperature to form an ANF solution includes:

[0040] Crushing and separating the insulation structure of the recycled environmentally friendly motor, and separating metal impurities in the insulation structure by methods such as screening and magnetic separation to obtain MPIA staple fibers for deprotonation to form an ANF solution.

[0041] Compared with the prior art, the beneficial effects of the present invention at least include: The present invention adopts an insulating structure with a specific structure and specific materials to manufacture an environmentally friendly motor resistant to corona aging, achieving a simultaneous improvement in insulation performance and environmental protection level; specifically, this insulating material not only has excellent corona aging resistance, but also has the characteristics of being recyclable, with a simple preparation process and a green recycling path, and has good application prospects. The technical solution provided by the present invention can not only be used as an insulating component in the motor, but also be horizontally extended to other electrical equipment, serving as an insulating component for electrical insulation, mechanical support, and heat dissipation, improving the corona aging resistance and environmental protection level of these electrical equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 Schematic diagram of the stator of an environmentally friendly motor resistant to corona aging provided by the present invention;

[0043] Figure 2 Schematic diagram of the insulating structure of an environmentally friendly motor resistant to corona aging provided by the present invention;

[0044] Figure 3 Flow chart of the preparation method of the insulating material used in the insulating structure of an environmentally friendly motor resistant to corona aging provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. The described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the spirit of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0046] As Figure 1 shown, Embodiment 1 of the present invention provides an environmentally friendly motor resistant to corona aging, including: a stator core 10 and a stator winding. A stator slot 20 is provided on the stator core for placing the stator winding 30.

[0047] The stator core is the main part of the stator. Preferably but not limited to, it is formed by laminating a plurality of thin silicon steel sheets. The silicon steel sheets have low magnetic resistance and high resistivity, which can reduce eddy current losses. These silicon steel sheets are bonded together by an insulating agent to form a solid whole to support the mechanical structure of the stator and serve as the path of magnetic flux.

[0048] The stator winding is a coil, which is placed in the slot of the stator core. The stator winding generates a magnetic field through the current, interacts with the magnetic field of the rotor, and thus generates torque. The stator winding is, for example but not limited to, a scattered-embedded type or a whole-embedded type, specifically depending on the type and design of the motor.

[0049] As one of the prominent substantive features of the present invention, an insulating structure made of recyclable corona-resistant insulating material is provided in the stator slots, such as Figure 2 shown, the insulating structure includes: slot insulation 40 and inter-winding insulation 50. The slot insulation is laid on the inner wall of the stator slot, and the inter-winding insulation is arranged in the space enclosed by the stator slot. In the cross-sectional direction of the stator core, the space enclosed by the stator slot is divided into multiple parts to separate the stator windings wound in the stator slots. In combination with the insulating structure, the slot insulation and the inter-winding insulation are made of the same insulating material, and the insulating material includes: nano-scale MPIA short fibers and nano-titanium dioxide particles.

[0050] Preferably but not restrictively, as Figure 2 shown, the stator slot is a round-bottom slot structure, gradually narrowing from the round bottom towards the slot opening. The slot insulation is consistent with the shape of the inner wall of the stator slot, and at the slot opening, it extends towards the center of the slot opening. The inter-winding insulation includes longitudinal beams and cross beams extending from the longitudinal beams to both sides. The cross beams at the bottom of the slot are arc-shaped, pressing against the slot insulation at the bottom of the slot, and the cross beams at the slot opening close the slot opening and overlap with the slot insulation at the slot opening.

[0051] It should be noted that, as one of the prominent substantive features of the present invention and a significant improvement over the prior art, the present invention provides an insulating material with corona-resistant aging and recyclability, combined with a specific insulating structure, which significantly improves the corona-resistant aging performance of the motor. And this insulating material is a renewable material. When the motor reaches the end of its life cycle or when the insulating structure is updated, the insulating material can be recycled and reused. That is to say, the present invention simultaneously realizes the improvement of the motor's insulation performance and environmental protection level.

[0052] Specifically, the insulating material used to prepare the slot insulation and the inter-winding insulation includes: nano-scale MPIA short fibers and nano-titanium dioxide particles. Among them, the nano-scale MPIA short fibers are prepared by deprotonation of MPIA short fibers in the DMAc / LiCl system, and the diameter is 7 - 10 nanometers. The nano-titanium dioxide particles are in the rutile crystal form, with a particle size of 5 - 20 nanometers, a mass fraction of 10 - 20 wt%, and are uniformly distributed in the nano-scale MPIA short fibers.

[0053] The surface of the insulating material is smooth and pure white, with a thickness of 0.08 - 0.20 millimeters, and the interface is a honeycomb-like porous structure with a pore diameter of about 0.5 - 1 nanometer. It has extremely strong corona-resistant aging ability. After being aged under a strong DC electric field for 20 - 40 hours, parameters such as its breakdown field strength and tensile strength still remain at 90 - 95% of the state of the prior art, and the dielectric constant and dielectric loss are maintained at 94 - 98% of the state of the prior art.

[0054] When recycling the motor components, the slot insulation and the inter-winding insulation prepared from the insulating material can be deprotonated again in the DMAc / LiCl system to form an ANF / suspension, thereby achieving green and efficient chemical recycling. The recycling period is 20 - 30 hours, and the mass recovery rate is as high as 92 - 97%. After recycling, the insulation performance, mechanical performance, and dielectric performance of the insulating material can completely retain the existing technical level.

[0055] It should be noted that in the prior art, a bend-resistant composite mica tape is used to prepare the insulation structure in the motor. However, the total thickness of the bend-resistant composite mica tape is 0.8 - 1.5 mm, and the excessive thickness may affect its heat dissipation performance and service life. The base material it uses is a micron structure, which limits the insulation strength and mechanical strength. In contrast, in the present invention, the prepared MPIA insulating material has a thickness of 0.08 - 0.2 mm, has excellent heat dissipation performance and anti-aging ability provided by the embodiments of the present invention, and ensures its service life. The uniform and dense nano-structure ensures that the prepared theater structure has excellent insulation strength and mechanical strength.

[0056] Embodiment 2 of the present invention provides a manufacturing method of an anti-corona aging environmental protection motor as described in Embodiment 1, including the following steps:

[0057] Step 1: Manufacture a stator core including a stator slot structure with magnetic materials.

[0058] Preferably but not limitedly, Step 1 specifically includes:

[0059] Step 1.1: Use a precision punching machine to punch silicon steel sheets with high magnetic permeability, low iron loss, and good mechanical properties into a ring with a stator slot structure, and perform annealing treatment to eliminate internal stress and improve magnetic properties. Among them, the stator slot is a round-bottom slot structure, which gradually narrows from the round bottom towards the slot opening.

[0060] Step 1.2: Coat a layer of insulating material on the surface of the silicon steel sheet, preferably but not limited to, phosphate or organic coating, to reduce eddy current loss.

[0061] Step 1.3: Use a hydraulic press or a mechanical press to stack the punched silicon steel sheets together according to the design requirements; perform turning processing on the outer circle and inner hole of the stator core to ensure dimensional accuracy and surface finish; remove the burrs generated during punching and processing to avoid affecting the motor performance.

[0062] Step 2: Prepare an insulating material containing nano-scale MPIA short fibers and nano-titanium dioxide particle components, and respectively prepare slot insulation and inter-winding insulation based on this insulating material.

[0063] Preferably but not limitedly, as Figure 3 shown, Step 2 specifically includes:

[0064] Step 2.1: MPIA (Poly-m-phenylene isophthalamide) staple fibers are placed in a DMAc / LiCl system and deprotonated at a set temperature to form an ANF (Aramid NanoFiber) solution.

[0065] Further preferably but not limiting, in step 2.1, the deprotonation temperature is 130-150°C, deprotonation time For 6-10 hours, the concentration of LiCl The concentration of ANF is 0.02-0.04 g / mL. More preferably, the deprotonation temperature 140-145°C, deprotonation time For 8-10 hours, the concentration of LiCl The concentration of ANF is 0.027-0.035 g / mL. It is 0.067-0.075 g / mL.

[0066] It is worth noting that the present invention first recognizes that MPIA material is a polymer material with excellent thermal stability, excellent insulation strength, and super mechanical strength, and has broad application prospects in the insulation application of environmentally friendly motors. At the same time, MPIA staple fibers have the ability to be deprotonated into nanoscale MPIA in the DMAc / LiCl system, which not only creates favorable conditions for the incorporation of inorganic fillers with different characteristics, but also creates the possibility of efficient and green chemical recycling of MPIA-based materials. If MPIA materials can be used in the preparation of insulating materials, a high-performance insulating material that can be flexibly modified and recyclable can be provided, and the application of this material in motors will have great competitiveness.

[0067] Also, because the MPIA staple fibers have the ability to be deprotonated into nano-scale MPIA staple fibers in the DMAc / LiCl system, the deprotonated ANF solution can be regenerated in deionized water, reshape the physical structure, and restore the insulation capacity, providing a reliable path for energy-saving chemical closed-loop recycling. On this basis, the present invention performs anti-corona aging modification, and the provided recyclable and anti-corona aging environmentally friendly motor has greater application potential.

[0068] On the one hand, in the prior art, organic solvents such as DMSO (Dimethyl Sulfoxide) and DMF (Dimethylformamide) are used to dissolve, process or modify insulating materials during the manufacturing and processing of motor insulating materials. Usually, they are paired with other chlorides, but it is difficult to fully deprotonate the surface of the insulating materials. As one of the prominent substantive features of the present invention, deprotonation is carried out at 140 °C in the DMAc / LiCl system, so that the MPIA short fibers are fully deprotonated into MPIA short fibers with uniform nanoscale dimensions. The produced insulating material has a dense and uniform nanostructure, ensuring excellent mechanical strength and insulating strength in the motor stator.

[0069] On the other hand, in the prior art, micron-structured MPIA insulating materials are used to prepare the insulating structure of the motor. However, the internal pores of the micron structure are large and unevenly distributed, resulting in uneven distribution of inorganic fillers. In contrast, the base material of the present invention is a nanostructure, which is prepared by deprotonating MPIA short fibers in the DMAc / LiCl system at 140 °C and has fewer internal pores. The interface of the prepared insulating material presents a honeycomb-like porous structure, and the pore diameter is about 0.5 - 1 nanometer.

[0070] Step 2.2: Grind the nano-titanium dioxide particles, and add the ground particles into the ANF solution and stir mechanically to form an ANF / mixture.

[0071] Further preferably but not restrictively, the nano-titanium dioxide particles are of rutile crystal form, the particle size of the nano-titanium dioxide is 5 - 20 nanometers, the mass fraction is 10 - 20 wt%, and the mechanical stirring duration is 0.5 - 1 hour. More preferably, the particle size of the nano-titanium dioxide is 5 - 10 nanometers, the mass fraction is 15 - 20 wt%, and the mechanical stirring duration is 0.75 - 1 hour.

[0072] It should be noted that titanium dioxide particles have the ability to absorb high-energy particle rays. Incorporating them into the polyimide film can effectively reduce the influence of corona aging, greatly reducing the surface roughness of the film after aging. The incorporation of nano-titanium dioxide significantly improves the thermal aging resistance of the MPIA material. The present invention further realizes that if reducing the influence of corona aging is the focus of modification, using nano-titanium dioxide particles as fillers is a better choice.

[0073] Meanwhile, in the prior art, the particle size and crystal form of titanium dioxide are not strictly controlled. Moreover, after being modified by dopamine and γ-aminopropyltriethoxysilane, the preparation process is cumbersome and the recyclability cannot be guaranteed. As a result, the service life of the produced insulating material and the anti-aging ability provided by the embodiments of the present invention cannot be ensured. As another prominent substantive feature of the present invention, the present invention clearly uses rutile crystal form and titanium dioxide particles with a particle size of 5-20 nanometers as inorganic fillers, ensuring excellent insulation strength and mechanical strength of the prepared MPIA insulating material. Moreover, it can be directly incorporated without modification, the preparation process is simple and convenient for recycling, and the prepared MPIA insulating material has extremely strong anti-corona aging ability.

[0074] Furthermore, it is worth noting that compared with the prior art where inorganic fillers only deposit on the surface of the insulating material and cannot effectively modify the interior, and the adhesion of the inorganic fillers and the durability of the insulating material cannot be guaranteed. As an inseparable technical feature from step 2.1, the prepared MPIA insulating material uses nano-scale MPIA short fibers as the substrate, has a smooth surface and a honeycomb-like dense and uniform interface, and the titanium dioxide particles are evenly distributed inside the insulating material. The internal structure of the prepared MPIA insulating material is uniform and has no obvious defects. As a result, the prepared MPIA insulating material has excellent wear resistance and service life.

[0075] Step 2.3: Subject the mixture obtained in step 2.2 to coating on a coating machine with a set coating thickness for coating.

[0076] Further preferably but not restrictively, in step 2.3, the coating thickness is 0.8-1.2 mm, and the size is 10 cm × 15 cm. More preferably, the coating thickness is 0.8-1 mm.

[0077] Step 2.4: Leave the ANF / film obtained in step 2.3 to stand in deionized water for a set standing time for reduction to form ANF / aerogel.

[0078] Further preferably but not restrictively, in step 2.4, the standing time in deionized water is 10-15 hours. More preferably, the standing time is 13-15 hours.

[0079] Step 2.5: Dry the ANF / aerogel obtained in step 2.4 at a set drying temperature and drying time for drying, and at a set hot pressing temperature , hot pressing pressure and hot pressing duration Perform hot pressing to obtain a recyclable and corona-resistant MPIA insulating material.

[0080] Further preferably but not restrictively, in step 2.5, the drying temperature is 60 - 100 °C, the drying duration is 0.5 - 1 hour, the hot pressing temperature is 160 - 200 °C, the hot pressing pressure is 15 - 20 MPa, the hot pressing duration is 1 - 2 minutes, and the thickness after hot pressing is 0.08 - 0.2 mm. More preferably, the drying temperature is 80 - 100 °C, the drying duration is 0.75 - 1 hour, the hot pressing temperature is 180 - 200 °C, the pressure is 18 - 20 MPa, the hot pressing duration is 1.5 - 2 minutes, and the thickness after hot pressing is 0.08 - 0.1 mm.

[0081] It should be noted that in the prior art, there is no hot pressing operation after the insulation material is formed, and the overall structure is relatively loose. As another prominent substantial feature of the present invention, the present invention proposes that the insulation material is subjected to sufficient hot pressing treatment after drying, and the structure is dense. After hot pressing, the surface of the insulation material is smooth and pure white, and the thickness is 0.08 - 0.20 mm.

[0082] Further preferably but not restrictively, Example 2 provides an equation for quickly designing the process parameters of the preparation method, which is expressed by the following formula:

[0083]

[0084] In the formula:

[0085] represents the thickness after hot pressing, that is, the thickness of the prepared insulation material, represents the coating thickness;

[0086] represents the particle size of nano-titanium dioxide, represents the diameter of nano-scale MPIA short fibers, represents the pore diameter of the honeycomb-like porous structure at the interface of the insulation material;

[0087] represents the hot pressing pressure, represents the standard atmospheric pressure;

[0088] is the deprotonation temperature, Indicates room temperature;

[0089] represents the deprotonation time, Indicates natural day time, i.e. 24 hours;

[0090] represents the concentration of ANF, represents the concentration of LiCl, represents a natural constant;

[0091] and They represent adjustment constants respectively and are debugged according to the production equipment.

[0092] Step 2.6: The insulating material obtained in step 2.5 is cut according to the stator slot type, winding size and insulation requirements of the motor, and prepared into slot body insulation and inter-winding insulation.

[0093] Further preferably but not restrictively, the slot body insulation is consistent with the shape of the inner wall of the stator slot and extends toward the center of the slot at the slot opening. The inter-winding insulation includes a longitudinal beam and a cross beam extending from the longitudinal beam to both sides. The cross beam at the bottom of the slot is arc-shaped and abuts against the slot body insulation at the bottom of the slot. The cross beam at the slot opening closes the slot and overlaps with the slot body insulation at the slot opening.

[0094] Step 3: Insert the prepared slot insulation into the stator slot, ensuring that the insulation paper completely covers the slot wall and leaves enough margin; and insert inter-winding insulation between different layers of the winding to prevent inter-layer short circuit.

[0095] Preferably, but not restrictively, glue or tape is used to fix the slot body insulation in the slot to ensure that it does not shift or fall off; and the edges of the insulating paper are folded or trimmed neatly to avoid burrs or warping; tools are used to compact the insulation between the windings to ensure that it fits tightly with the windings.

[0096] Step 4: Install the rotor core, permanent magnets or windings, perform dynamic balancing tests, and install other structures to complete the assembly.

[0097] Preferably, but not restrictively, the rotor core is fixed on the shaft to ensure that it is accurately and firmly positioned; for permanent magnet motors, the permanent magnets are fixed on the rotor core; for wound rotors, the rotor windings are embedded in the rotor slots; and the rotor is dynamically balanced to ensure that it does not produce excessive vibration when rotating at high speed.

[0098] Fix the end cover to the casing and ensure that it fits tightly with the casing; for motors that need cooling, install fans and wind shields to ensure that they operate normally; fix the junction box to the casing and connect the leads of the stator winding.

[0099] Overall, as a manufacturing method of an environmentally friendly motor with corona aging resistance provided by the present invention, compared with the prior art, the preparation process is greatly simplified, and closed-loop recycling is achieved. Specifically, in the prior art, the recycling of insulating materials requires using a dissolution solution to deprotonate both sides of the insulating material respectively, and then using a strengthening solution to treat the deprotonated surface. The processes of surface reprotonation and regeneration are both time-consuming, and it is difficult to achieve efficient and green closed-loop recycling. The substrate and inorganic fillers of the insulating materials prepared by this process are unevenly distributed. The surface of the insulating material after being treated with the dissolution solution is a nanostructure, while the interface is a micron structure, and the inorganic fillers are only distributed in the surface nanostructure, making it difficult to effectively modify the interior of the insulating material. In contrast, in the present invention, MPIA short fibers are directly used as the substrate to prepare the stock solution and coat the film. The substrate has a uniform nanostructure at the nanoscale. With sufficient mechanical stirring, the inorganic fillers are evenly distributed therein, having a smooth surface and a honeycomb-like dense and uniform interface, and titanium dioxide particles are evenly distributed inside the insulating material. After corona aging under an extremely uneven DC strong electric field, the performance of the prepared renewable insulating material still maintains the level of the prior art, and it has extremely strong anti-aging ability provided by the embodiments of the present invention. The overall process can rapidly prepare in large quantities and achieve efficient and green closed-loop recycling, and the recycled insulating material completely retains the performance of the insulating material of the prior art.

[0100] Embodiment 3 of the present invention provides a recycling method for an environmentally friendly motor with corona aging resistance as described in Embodiment 1, including the following steps:

[0101] Step 1: Disassemble the environmentally friendly motor to obtain windings, magnetic components, and insulating structures;

[0102] Step 2: Crush and separate the insulating structure, separate metal impurities in the insulating structure by methods such as screening and magnetic separation, and reintroduce the separated insulating structure components into the insulating material preparation process to complete the regeneration of the insulating material.

[0103] Preferably but not restrictively, the recyclable MPIA insulating material with corona aging resistance is deprotonated in the DMAc / LiCl system at a set deprotonation temperature and deprotonation time to form an ANF / suspension;

[0104] The obtained ANF / mixture is coated on a coating machine with a set coating thickness for coating;

[0105] The obtained ANF / film is allowed to stand for a set standing time Let it stand in deionized water for reduction to form ANF / aerogel;

[0106] Let the obtained ANF / aerogel be dried at a set drying temperature and drying duration to perform drying, and perform hot pressing at a set hot pressing temperature , hot pressing pressure and hot pressing duration to complete the chemical recycling of the MPIA insulating material.

[0107] It should be noted that, as the prominent substantial feature of the present invention and the significant progress brought to the prior art, after adopting the said recycling method, the recycling period is 20 - 30 hours, and the mass recovery rate is as high as 92 - 97%. The insulation performance, mechanical performance, and dielectric performance of the recycled insulating material can all completely retain the prior art level.

[0108] Step 3: Recycle structures such as windings and magnetic components respectively according to the recycling processes of metal materials and magnetic materials.

[0109] In order to more clearly introduce the prominent substantial feature of the present invention and the significant progress brought to the prior art, the following introduces multiple application examples of implementing the present invention.

[0110] Application Example 1

[0111] According to the manufacturing method of an environmentally friendly motor with anti-corona aging provided in Example 2, prepare insulating materials, specifically including: take two portions each of 45 mL of DMAc, 1.2 g of LiCl, and 3 g of MPIA short fibers, deprotonate at 140 °C for 6 hours respectively to prepare nano-scale MPIA short fiber solutions. Add 0.75 g of ground nano-titanium dioxide to one of them, and mechanically stir at room temperature for 1 hour. Coat the two stock solutions on a coating machine respectively, with a coating thickness of 1 mm, and let them stand in deionized water for 10 hours to obtain pure ANF aerogel and ANF / aerogel respectively. Dry the two aerogels at 80 °C for 30 minutes, and after hot pressing at 200 °C and 20 MPa for 2 minutes, obtain pure ANF insulating material and ANF / composite insulating material respectively. Take 5 cm × 5 cm specimens of the two insulating materials, and simultaneously perform aging experiments on the two specimens with a multi-needle plate electrode. The aging voltage is 10 kV for both, the aging duration is 20 hours for both, and the distance between the needle tips and the specimens is 1 mm. Measure the breakdown field strength and tensile strength of the two samples before and after aging respectively. The above test results are shown in Table 1. It can be seen that after aging under this condition, the decline amplitudes of the two performances of the anti-aging insulating material provided by the embodiment of the present invention are both smaller than those of the insulating material of the prior art.

[0112] Table 1 10 kV / 20h Aging Test Experimental Data

[0113]

[0114] Application Example 2

[0115] The preparation processes and parameters of the two samples are the same as those in Application Example 1. At the same time, the two specimens are aged using a multi-needle-plate electrode. The aging voltage is 20 kV for both, the aging duration is 20 hours for both, and the distance between the needle tip and the specimen is 1 mm. The breakdown field strength and tensile strength of the two samples before and after aging are measured respectively. The above test results are shown in Table 2. It can be seen that after aging under this condition, the decline amplitude of each performance of the anti-aging insulating material provided by the embodiment of the present invention is less than that of the insulating material of the prior art.

[0116] Table 2 20 kV / 20h Aging Test Experimental Data

[0117]

[0118] Application Example 3

[0119] The preparation processes and parameters of the two samples are the same as those in Application Example 1. At the same time, the two specimens are aged using a multi-needle-plate electrode. The aging voltage is 10 kV for both, the aging duration is 40 hours for both, and the distance between the needle tip and the specimen is 1 mm. The breakdown field strength and tensile strength of the two samples before and after aging are measured respectively. The above test results are shown in Table 3. It can be seen that after aging under this condition, the decline amplitude of each performance of the anti-aging insulating material provided by the embodiment of the present invention is less than that of the insulating material of the prior art.

[0120] Table 3 10 kV / 40h Aging Test Experimental Data

[0121]

[0122] Application Example 4

[0123] The preparation processes and parameters of the two samples are the same as those in Application Example 1. At the same time, the two specimens are aged using a multi-needle-plate electrode. The aging voltage is 20 kV for both, the aging duration is 40 hours for both, and the distance between the needle tip and the specimen is 1 mm. The breakdown field strength and tensile strength of the two samples before and after aging are measured respectively. The above test results are shown in Table 4. It can be seen that after aging under this condition, the decline amplitude of each performance of the anti-aging insulating material provided by the embodiment of the present invention is less than that of the insulating material of the prior art.

[0124] Table 4 20 kV / 40h Aging Test Experimental Data

[0125]

[0126] Application Example 5

[0127] ANF / The preparation process and parameters of the composite insulating material are the same as those in Application Example 1. The aging experiment was carried out on the specimen with a multi-needle plate electrode. The aging voltage was 20 kV and the aging duration was 40 hours. 3.3 g of the aged sample was collected for recycling. The mass fraction of titanium dioxide was 10 wt%, and the mass of ANF obtained was 3 g. 45 mL of DMAc and 1.2 g of LiCl were taken and recycled according to the original solution concentration. The parameters in the steps of protonation, coating, standing in deionized water, drying, and hot pressing were the same as those in Example 1. The breakdown field strength and tensile strength of the sample before and after recycling were tested. The above test results are shown in Table 5. After recycling, the two properties of the insulating material aged under this condition have recovered to the prior art level, and the recyclability is verified.

[0128] Table 5 Test data of 20 kV / 40h aging test before and after recycling

[0129]

[0130] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the specific implementation manners of the present invention can still be modified or equivalently replaced, and any modification or equivalent replacement without departing from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. An environment-friendly motor resistant to corona aging, comprising: A stator core and a stator winding are provided. The stator core is provided with stator slots for placing the stator winding. It is characterized in that: The stator core is formed by laminating a plurality of silicon steel sheets, and the stator winding is placed in the slots of the stator core. An insulating structure made of recyclable corona-resistant insulating material is provided in the stator slots. The insulating structure includes: slot insulation and inter-winding insulation. The slot insulation is laid on the inner wall of the stator slots, and the inter-winding insulation is arranged in the space surrounded by the stator slots. In the cross-sectional direction of the stator core, the space surrounded by the stator slots is divided into multiple parts to separate the stator windings wound in the stator slots. The insulating material contains: nano-scale MPIA short fibers and nano-titanium dioxide particles; the nano-scale MPIA short fibers are prepared by deprotonating MPIA short fibers in the DMAc / LiCl system; the preparation process includes: The MPIA staple fiber is deprotonated in the DMAc / LiCl system at a set temperature to form an ANF solution, where the deprotonation temperature t DH is 130 - 150 °C, and the time T DH is 6 - 10 hours, the concentration C of LiCl LiCl is 0.02 - 0.04 g / mL, and the concentration C of ANF ANF is 0.06 - 0.08 g / mL; Grind nano-titanium dioxide particles, add the ground particles to an ANF solution and stir mechanically to form an ANF / TiO2 mixture, where the nano-titanium dioxide particles are in the rutile crystal form and the particle size D of the nano-titanium dioxide TiO2 is 5 - 20 nm, and the mass fraction M TiO2 is 10 - 20 wt%, and the mechanical stirring duration T stir is 0.5 - 1 hour; The obtained ANF / TiO2 mixture is coated on a film coater with a set coating thickness h film where the coating thickness h film is 0.8 - 1.2 mm and the size is 10 cm × 15 cm; The obtained ANF / TiO2 aerogel is dried at the set drying temperature t dry and drying duration T dry and then hot-pressed at the set hot-pressing temperature t HP , hot-pressing pressure p HP and hot-pressing duration T HP ; wherein, the drying temperature t dry is 60 - 100 °C, the drying duration T dry is 0.5 - 1 hour, the hot-pressing temperature t HP is 160 - 200 °C, the hot-pressing pressure p HP is 15 - 20 MPa, the hot-pressing duration T HP is 1 - 2 minutes, and the thickness h HP after hot-pressing is 0.08 - 0.2 mm.

2. The environmentally friendly motor with corona-resistant aging according to claim 1, characterized in that: The stator slots are of a round-bottom slot structure, gradually narrowing from the round bottom towards the slot opening. The slot insulation is in the same shape as the inner wall of the stator slots and extends towards the center of the slot opening at the slot opening. The inter-winding insulation includes longitudinal beams and cross beams extending from the longitudinal beams to both sides. The cross beams at the bottom of the slot are arc-shaped and abut against the slot insulation at the bottom of the slot. The cross beams at the slot opening enclose the slot opening and overlap with the slot insulation at the slot opening.

3. The environmentally friendly motor with corona-resistant aging according to claim 1, characterized in that: The surfaces of the slot insulation and the inter-winding insulation are smooth and pure white, and the interface is a honeycomb-like porous structure with a pore diameter of 0.5 - 1 nanometer. After aging under a strong DC electric field for 20 - 40 hours, the breakdown field strength and tensile strength of the slot insulation and the inter-winding insulation still retain 90 - 95% of the original state, and the dielectric constant and dielectric loss are maintained at 94 - 98% of the existing technology state.

4. A manufacturing method of an environmentally friendly motor resistant to corona aging, for manufacturing an environmentally friendly motor resistant to corona aging according to any one of claims 1 to 3, characterized in that, It includes the following steps: Manufacture a stator core including a stator slot structure with a magnetic material. Prepare an insulating material containing nano-scale MPIA short fibers and nano-titanium dioxide particle components, and respectively prepare slot insulation and inter-winding insulation based on this insulating material. Insert the prepared slot insulation into the stator slots, ensure that the insulating paper completely covers the slot walls and leave a margin; insert inter-winding insulation between different layers of the windings to prevent inter-layer short circuits. Install the rotor core, permanent magnets or windings, conduct a dynamic balance test, and install other structures to complete the overall assembly.

5. The manufacturing method of the environmentally friendly motor with corona-resistant aging according to claim 4, characterized in that: The manufacturing of the stator core including a stator slot structure with a magnetic material includes: Use a punching machine to punch the silicon steel sheets into an annular shape with a stator slot structure and perform annealing treatment. Among them, the stator slots are of a round-bottom slot structure, gradually narrowing from the round bottom towards the slot opening. Coat a layer of insulating material on the surface of the silicon steel sheets. Stack the punched silicon steel sheets together according to the design requirements; perform turning processing on the outer circle and inner hole of the stator core, and remove the burrs generated during punching and processing.

6. The manufacturing method of the environmentally friendly motor with corona-resistant aging according to claim 5, characterized in that: The heat-pressed insulating material is cut according to the stator slot shape, winding size and insulation requirements of the motor, and is prepared into slot insulation and inter-winding insulation, including: The prepared slot insulation is consistent with the shape of the inner wall of the stator slot, and at the slot opening, it extends towards the center of the slot opening. The inter-winding insulation includes longitudinal beams and cross beams extending from the longitudinal beams to both sides. The cross beams at the bottom of the slot are arc-shaped and abut against the slot insulation at the bottom of the slot. The cross beams at the slot opening close the slot opening and overlap with the slot insulation at the slot opening.

7. The manufacturing method of an anti-corona aging environmental protection type motor according to claim 5, characterized in that: The deprotonation of the MPIA short fibers in the DMAc / LiCl system at a set temperature to form an ANF solution includes: The insulating structure of the recycled environmental protection type motor is crushed and separated, and metal impurities in the insulating structure are separated by screening or magnetic separation methods to obtain MPIA short fibers for deprotonation to form an ANF solution.

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