A motor rotor and a processing method thereof

Abstract

The application relates to the technical field of motor rotors, and discloses a motor rotor and a processing method thereof. The method comprises the following steps: hot forging an alloy steel base material based on a preset forging temperature, performing multi-layer gradient cutting on a rotor initial blank, performing composite deposition treatment on a cylindrical blank based on a magnetic material, placing a magnetic composite blank in a vacuum environment for dynamic heat treatment, performing dynamic balance trimming on the heat-treated blank based on a preset alloy, performing surface strengthening treatment on the balanced rotor in a nitrogen atmosphere, coating the surface-strengthened balanced rotor with preset paint, and obtaining a surface-optimized motor rotor. Dynamic balance trimming is combined with microstructure regulation based on the characteristics of the preset alloy, so that the rotor has excellent running stability in a high-speed environment. Finally, surface strengthening treatment is performed in a nitrogen atmosphere, and a functional coating is additionally applied, so that the surface wear resistance and corrosion resistance are significantly improved, and the demand of a motor system on a high-performance rotor under complex working conditions is met.

Description

Technical Field

[0001] This invention relates to the field of motor rotor technology, and more specifically, to a motor rotor and its processing method. Background Technology

[0002] With the continuous development of industrial automation and intelligent manufacturing, motors, as the core power source of various electromechanical equipment, directly affect the operating efficiency and stability of the entire equipment. The motor rotor, as a key component of the motor, plays a crucial role in ensuring efficient operation, reducing energy consumption, and extending service life through its structural design and manufacturing process. Currently, the manufacturing process of motor rotors is gradually evolving towards higher precision, higher performance, and higher reliability, especially in fields such as new energy vehicles, aerospace, and high-end manufacturing equipment, where higher performance requirements are being placed on motor rotors.

[0003] In existing technologies, the processing of motor rotors typically involves preparing a blank by forging at a single temperature and then directly cooling it. This blank is then subjected to mechanical cutting and a single heat treatment before surface treatment is completed. This method can easily lead to uneven grain distribution within the material during the cooling process, which in turn affects the dynamic balance performance of the rotor. Especially in applications with high speeds or large load variations, this unevenness may cause vibration amplification during rotor operation, reduce motor efficiency, and even shorten the service life.

[0004] Therefore, there is a need to provide a motor rotor and its processing method to solve the problem of poor dynamic balance performance of existing motor rotors. Summary of the Invention

[0005] The main objective of this invention is to provide an electric motor rotor and its processing method, aiming to solve the technical problems mentioned in the background section.

[0006] The present invention adopts the following technical solution:

[0007] An electric motor rotor and its processing method, comprising:

[0008] The alloy steel substrate is hot-forged based on a preset forging temperature, and then the hot-forged alloy steel substrate is subjected to gradient cooling treatment to obtain the rotor blank.

[0009] The rotor blank is subjected to multi-layer gradient cutting to obtain a cylindrical blank;

[0010] A magnetic composite billet is obtained by performing a composite deposition process on the cylindrical billet based on magnetic materials.

[0011] The magnetic composite blank is placed in a vacuum environment for dynamic heat treatment to obtain a heat-treated blank.

[0012] The heat-treated billet is dynamically balanced and trimmed based on a preset alloy to obtain a balanced rotor.

[0013] The balanced rotor is subjected to surface strengthening treatment under a nitrogen atmosphere, and then coated with a preset coating to obtain a motor rotor with optimized surface.

[0014] Furthermore, the alloy steel substrate is a mixture of chromium, molybdenum, carbon, nickel, vanadium and iron, wherein, by mass percentage, chromium accounts for 1.5-3%, molybdenum accounts for 0.5-1.2%, carbon accounts for 0.3-0.6%, nickel accounts for 0.8-1.5%, vanadium accounts for 0.1-0.25%, and the balance is iron.

[0015] Further, the step of hot forging the alloy steel substrate based on a preset forging temperature and then subjecting the hot-forged alloy steel substrate to gradient cooling to obtain the rotor blank includes:

[0016] The alloy steel substrate is preheated to 900-950°C in an inert gas atmosphere to obtain a preheated substrate.

[0017] The preheated substrate is subjected to multi-directional hot forging at a forging frequency of 12 to 18 times per minute and an extrusion angle of 30° to 45° to obtain a preliminary forging billet;

[0018] The initial forging billet is placed in an environment of 700~800℃ and kept for 2 hours. Then, cold air is sprayed onto the outer surface of the initial forging billet to cool it down to 650℃, forming an annealed billet.

[0019] The annealed billet is cooled to 450°C at a rate of 4°C / min using a circulating liquid cooling system. Then, argon gas is injected into the annealed billet at a preset injection angle to assist in cooling it to room temperature, thus obtaining a pre-cooled billet.

[0020] The pre-cooled billet is tempered at 300~350℃ for 2 hours, and the tempered pre-cooled billet is cooled to 150℃ based on a nitrogen circulation system to obtain a fine-tuned billet.

[0021] The fine-tuning billet is cooled to 80°C at a rate of 1.5°C / min, and then the fine-tuning billet is naturally cooled to room temperature to obtain the rotor blank.

[0022] Further, the step of performing multi-layer gradient cutting on the rotor blank to obtain a cylindrical blank includes:

[0023] The rotor blank is fixed and preheated to 200°C. The outer surface of the preheated rotor blank is rough-cut by 3-5 mm at a speed of 600 rpm to obtain a rough-machined blank.

[0024] The rough-machined blank is subjected to layered peeling and cutting to obtain a layered blank, and the layered blank is then precisely cut at a frequency of 30kHz with ultrasonic assistance to obtain a fine-cut blank.

[0025] The precision-cut blank is dynamically contoured using a coordinate measuring machine to obtain a trimmed blank. The trimmed blank is then tempered at 150°C for 2 hours and then cut to the target size using a precision lathe with a cutting depth of 0.3~0.5 mm to obtain a preformed blank.

[0026] The outer surface of the preformed blank is polished and cut at a preset polishing speed to obtain a cylindrical blank.

[0027] Further, the step of performing composite deposition treatment on the cylindrical blank based on magnetic materials to obtain a magnetic composite blank includes:

[0028] Based on plasma cleaning equipment The cylindrical blank is bombarded with plasma in the working air pressure to obtain an activated blank;

[0029] The activated billet was subjected to ion carburizing treatment in a mixed gas atmosphere of methane and nitrogen to obtain a carburized billet;

[0030] A primary magnetic blank is obtained by spraying magnetic material onto the carburized billet using a high-frequency plasma arc, and then... The primary magnetic blank is subjected to hot pressing and curing treatment under working air pressure to obtain a cured magnetic blank.

[0031] The solidified magnetic blank is subjected to magnetic field orientation optimization treatment to obtain an oriented magnetic blank, and the surface of the oriented magnetic blank is subjected to plasma polishing treatment using a mixed gas of argon and oxygen as a polishing medium to obtain a magnetic composite blank.

[0032] Further, the step of placing the magnetic composite blank in a vacuum environment for dynamic heat treatment to obtain a heat-treated blank includes:

[0033] exist Under the working air pressure, the magnetic composite blank is first heated to 600°C at a heating rate of 8°C / min and held for 1.5 hours, and then heated to 900°C at a heating rate of 12°C / min and held for 2 hours to obtain a reinforced blank with an enhanced magnetic layer.

[0034] The reinforced billet was cooled to 700°C at a rate of 5°C / min and held for 1 hour, then cooled to 550°C at a rate of 3°C / min and held for 2 hours, and then cooled to 400°C at a rate of 2°C / min and held for 1.5 hours to obtain a lattice-optimized billet.

[0035] A constant magnetic field of 0.5 Tesla is applied to the lattice-optimized billet, and the temperature is raised from 400°C to 650°C at a rate of 5°C / min and held for 1 hour, and then cooled to 300°C at a rate of 4°C / min to obtain a magnetically optimized billet.

[0036] The magnetically optimized billet was cooled to 150°C at a rate of 2°C / min and held for 2.5 hours in an inert gas atmosphere to obtain a stable billet.

[0037] The stabilized billet is cooled to room temperature at a rate of 1.5°C / minute, with a 10-minute pause every 50°C decrease during the cooling process, to obtain a heat-treated billet.

[0038] Further, the step of dynamically balancing and trimming the heat-treated billet based on a preset alloy to obtain a balanced rotor includes:

[0039] The heat-treated billet is subjected to initial rotation detection based on a dynamic balancing testing platform to obtain the initial vibration distribution characteristics of the heat-treated billet.

[0040] The initial vibration distribution characteristics are deconstructed by Fourier transform and vector decomposition, the eccentric region of the heat-treated billet is calculated and marked, and the positioning billet is obtained.

[0041] Using plasma spraying equipment, cobalt-based alloy powder is locally pre-deposited onto the positioning billet to obtain a pre-repaired billet.

[0042] The pre-repaired billet is heated to 600°C at a rate of 5°C / min and held for 20 minutes. During the heating process, the pre-repaired billet is simultaneously subjected to vibration at a frequency of 40 kHz to obtain a fine-tuned billet.

[0043] The fine-tuned billet is subjected to secondary balance verification based on the dynamic balance testing platform. The verification results are compared and analyzed with the initial vibration distribution characteristics to generate a residual eccentricity distribution map.

[0044] Based on the residual eccentricity distribution diagram, a nickel-based alloy is locally deposited on the fine-tuning billet by electron beam welding to obtain a dynamically balanced rotor.

[0045] Further, the step of performing surface strengthening treatment on the balanced rotor under a nitrogen atmosphere and coating the surface-strengthened balanced rotor with a preset coating to obtain a surface-optimized motor rotor includes:

[0046] The balanced rotor was subjected to ion nitriding treatment under a nitrogen atmosphere to obtain a nitrided rotor.

[0047] The nitrided rotor was immersed in a composite electrolyte for micro-arc oxidation treatment to obtain an oxidation-enhanced rotor. The composite electrolyte contained silicate, phosphate and alumina powder, wherein the concentration of silicate was 20 g / L, the concentration of phosphate was 30 g / L, the concentration of alumina powder was 50 g / L, the voltage of micro-arc oxidation treatment was 450 V, the current density was 8 A / dm², and the oxidation time was 40 minutes.

[0048] Based on plasma spraying equipment, a ceramic coating deposition process is performed on the oxide-strengthened rotor using a preset coating material to obtain a composite coated rotor, wherein the preset coating material includes a mixture of alumina and zirconium oxide powder.

[0049] The surface of the composite coated rotor is subjected to laser remelting treatment to obtain a remelted and strengthened rotor. A high-purity titanium target is used as a deposition source to deposit a metal film on the remelted and strengthened rotor to obtain a rotor with optimized film layer.

[0050] The rotor with optimized film layer is coated with a fluorinated polyurethane pre-coating at low temperature to obtain a motor rotor with optimized surface.

[0051] An electric motor rotor, using the above-described machining method, includes a shaft and a core, the core being sleeved on the outside of the shaft, the shaft having an elliptical fixing groove along its axial direction, and the core being fixedly connected to the shaft through the fixing groove.

[0052] The outer surface of the core is covered with a magnetic composite layer, and a plurality of magnetic pole units are embedded in the outer surface of the magnetic composite layer along the circumferential direction. The cross-section of the magnetic pole unit is trapezoidal, and an isolation strip is provided between two adjacent magnetic pole units.

[0053] Furthermore, the core is provided with balance reinforcing rings at opposite ends, and the balance reinforcing rings are provided with a plurality of balance holes along the axial direction, and the balance holes are coated with a counterweight alloy layer.

[0054] Beneficial effects:

[0055] In this invention, by hot forging the alloy steel substrate at a preset forging temperature and supplementing it with gradient cooling, the grain structure can be optimized while retaining the material strength, significantly improving the uniformity and isotropy of the initial billet. This helps reduce internal stress concentration during processing, improving the dynamic balance foundation of the rotor from the source. The cylindrical billet obtained through a multi-layer gradient cutting process allows for precise control of different structural layers, improving the geometric accuracy and surface quality of the billet. Furthermore, composite deposition of magnetic materials on the cylindrical billet allows for the on-demand construction of key magnetic functional areas, enhancing overall magnetic permeability while also meeting the requirements for lightweight materials. Dynamic heat treatment in a vacuum environment, combined with coordinated control of temperature and atmosphere, effectively suppresses structural defects and oxidation reactions, improving material stability and comprehensive mechanical properties. Dynamic balance trimming, combined with preset alloy characteristics, enables microstructure regulation, ensuring excellent rotor stability at high speeds. Finally, surface strengthening treatment in a nitrogen atmosphere, supplemented by a functional coating, significantly improves surface wear resistance and corrosion resistance, meeting the requirements of motor systems for high-performance rotors under complex operating conditions. Attached Figure Description

[0056] Figure 1 This is a schematic flowchart of a method for processing an electric motor rotor according to the present invention;

[0057] Figure 2 This is a schematic diagram of the overall structure of a motor rotor according to the present invention;

[0058] Figure 3 This is a schematic diagram of the structure of the shaft of the present invention.

[0059] The components are: 1. Shaft; 101. Fixing groove; 2. Core; 3. Magnetic pole unit; 4. Balance reinforcing ring; 401. Balance hole.

[0060] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0061] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0062] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0063] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0064] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0065] Reference Figure 1 This invention proposes a motor rotor and its processing method, comprising:

[0066] S1: The alloy steel substrate is hot-forged based on the preset forging temperature, and the hot-forged alloy steel substrate is subjected to gradient cooling treatment to obtain the rotor blank;

[0067] In step S1, the high-strength alloy steel substrate is placed in a multi-directional forging press. A preset heating zone is set according to the material processing requirements. Stress distribution data during the forging process is collected by a multi-axial pressure sensor. The forging frequency and extrusion angle are adjusted according to the stress distribution. At least three rounds of repeated extrusion are performed. After each round of extrusion, the grain size change data is recorded and the forging path is iteratively optimized until the grains are refined into a uniform rod-shaped structure. Subsequently, the forging is transferred to a cooling tank. The cooling rate is calculated in segments using a temperature gradient control module. The temperature is first lowered according to a preset curve, and then switched to a natural cooling mode. The cooling time is adjusted based on heat conduction simulation data to obtain a rotor blank with a uniform microstructure.

[0068] S2: Perform multi-layer gradient cutting on the rotor blank to obtain a cylindrical blank;

[0069] In step S2, the rotor blank is fixed on a CNC lathe. The rough cutting path is determined by the cutting parameter optimization algorithm to remove the surface allowance. The cutting speed and rotation speed are set, the surface contour data after each cut is recorded, and the tool feed is dynamically adjusted. Then, the cutting mode is switched to fine cutting mode. The cutting depth is reduced layer by layer based on the previous rough cutting contour data. It can be set to 0.5mm. The internal defect signal is collected by the ultrasonic testing equipment. The cutting trajectory is iteratively corrected according to the signal feedback until the surface roughness meets the standard, and a cylindrical blank with a regular shape is obtained.

[0070] S3: The cylindrical blank is subjected to composite deposition treatment based on magnetic materials to obtain a magnetic composite blank;

[0071] In step S3, the cylindrical billet is placed in a vacuum deposition furnace. Using a plasma-enhanced chemical vapor deposition system, the temperature and pressure are set, such as 450°C and 0.5Pa. A mixture of nitrogen and borane or other gases is introduced through a gas flow controller. The gas flow ratio is dynamically adjusted based on deposition rate monitoring data to generate a magnetic layer. Subsequently, the initial magnetization distribution of the magnetic layer is collected using a magnetic field orientation device. The optimal magnetic field orientation angle is calculated and a directional magnetic field is applied. The magnetic field strength and direction are iteratively adjusted until the magnetization direction is consistent with the axis, thus obtaining a magnetic composite billet.

[0072] S4: The magnetic composite blank is placed in a vacuum environment for dynamic heat treatment to obtain a heat-treated blank;

[0073] In step S4, the magnetic composite billet is placed in a vacuum heat treatment furnace, and the heating rate is set by a temperature curve planning algorithm. Specifically, it can be set from 10℃ / min to 850℃, and the temperature is held for 2 hours. The holding time is adjusted based on the thermal expansion data of the interface bonding state. Then, the temperature is dynamically reduced and held. The cooling rate calculation module is used to adjust the cooling to room temperature in stages, record the stress release data of each stage and optimize the cooling path to obtain a heat-treated billet with a stable microstructure and magnetic properties.

[0074] S5: Dynamically balance and trim the heat-treated billet based on a preset alloy to obtain a balanced rotor;

[0075] In step S5, the heat-treated billet is installed on a dynamic balancing machine. Real-time vibration data is collected using an eccentricity detection sensor, and the eccentricity position and mass compensation amount are calculated based on the vibration distribution. Subsequently, a counterweight alloy, such as a tungsten-based alloy, can be locally deposited at the eccentric part using equipment such as a laser cladding system. The cladding thickness is set to 0.1-0.3 mm. The laser power and scanning path are adjusted based on the heat-affected zone data during the cladding process. The adjustment is iteratively refined until the eccentricity is less than 0.01 g, resulting in a dynamically balanced rotor.

[0076] S6: The balanced rotor is subjected to surface strengthening treatment in a nitrogen atmosphere, and the surface-strengthened balanced rotor is coated with a preset coating to obtain a motor rotor with optimized surface.

[0077] In step S6, the balanced rotor is placed in an ion nitriding furnace, and nitrogen gas is introduced at 500°C and 0.8Pa pressure. The processing time is calculated based on the nitriding depth prediction model to generate a nitrided layer. Nitrogen atom diffusion data is recorded and the pressure and time parameters are adjusted. Subsequently, a nano-ceramic coating is applied using a low-temperature spraying device. A preset thickness is set, and the nozzle movement trajectory and coating deposition rate are optimized through a spraying uniformity analysis algorithm to obtain a surface-strengthened and durable final rotor.

[0078] In summary, by hot forging the alloy steel substrate at a preset forging temperature and supplementing it with gradient cooling, the grain structure can be optimized while preserving the material strength, significantly improving the uniformity and isotropy of the initial billet. This helps reduce internal stress concentration during processing, improving the dynamic balance foundation of the rotor from the source. The cylindrical billet obtained through a multi-layer gradient cutting process allows for precise control of different structural layers, improving the geometric accuracy and surface quality of the billet. Furthermore, composite deposition of magnetic materials on the cylindrical billet allows for the on-demand construction of key magnetic functional areas, enhancing overall magnetic permeability while also meeting the requirements for lightweight materials. Dynamic heat treatment in a vacuum environment, combined with coordinated control of temperature and atmosphere, effectively suppresses structural defects and oxidation reactions, improving material stability and comprehensive mechanical properties. The dynamic balance trimming step, combined with preset alloy characteristics, enables microstructure regulation, ensuring excellent rotor stability at high speeds. Finally, surface strengthening treatment in a nitrogen atmosphere, supplemented by a functional coating, significantly improves surface wear resistance and corrosion resistance, meeting the requirements of motor systems for high-performance rotors under complex operating conditions.

[0079] In one embodiment, the alloy steel substrate is a mixture of chromium, molybdenum, carbon, nickel, vanadium and iron, wherein, by mass percentage, chromium accounts for 1.5-3%, molybdenum accounts for 0.5-1.2%, carbon accounts for 0.3-0.6%, nickel accounts for 0.8-1.5%, vanadium accounts for 0.1-0.25%, and the balance is iron.

[0080] In the above embodiments, the composition of the alloy steel substrate is selected by precisely proportioning the content of each element to achieve ideal mechanical properties and thermal stability. The addition of chromium can significantly improve the corrosion resistance and high-temperature strength of the steel. During hot forging and subsequent heat treatment, chromium enhances grain boundary strength by forming stable carbides (such as Cr23C6), preventing excessive grain growth at high temperatures, thereby maintaining the microstructural stability of the rotor blank. In addition, chromium can also improve the surface strengthening effect of the substrate under a nitrogen atmosphere and promote the bonding force between the nitride layer and the matrix. The content is controlled in the range of 1.5% to 3%, which can give full play to its strengthening effect while avoiding the increase in brittleness caused by excessive content, ensuring the toughness of the material under high stress conditions.

[0081] Molybdenum helps enhance the hardenability and hot strength of materials. During hot forging, molybdenum strengthens the substrate through solid solution and precipitation mechanisms, enabling it to maintain high hardness and resistance to deformation at high temperatures. Furthermore, molybdenum improves the fatigue resistance of materials, which is crucial for the long-term stability of motor rotors operating at high speeds. A content range of 0.5% to 1.2% effectively improves mechanical properties while avoiding the increased processing costs and brittleness risks associated with excessive addition.

[0082] Carbon, as the primary hardening element in steel, is crucial for enhancing hardness and wear resistance. Carbon significantly improves the material's hardness and wear resistance by forming pearlitic or martensitic structures with iron. During hot forging and gradient cooling, an appropriate carbon content helps form a fine and uniform grain structure, providing a good surface quality foundation for subsequent machining. Simultaneously, carbon can form complex carbides with elements such as chromium and molybdenum, further enhancing the material's wear resistance. A carbon content range of 0.3% to 0.6% represents a balance point, ensuring sufficient strength while avoiding the decrease in toughness and increased machining difficulty caused by excessive carbon content.

[0083] The addition of nickel improves the low-temperature toughness and fatigue resistance of steel. Nickel, by dissolving in the iron matrix, improves grain boundary bonding and reduces internal stress concentration, which is particularly important during multi-layer gradient cutting and dynamic balancing. Furthermore, nickel enhances the material's corrosion resistance, and together with chromium, further extends the rotor's service life in complex environments. Maintaining a nickel content of 0.8%–1.5% optimizes toughness while avoiding unnecessary impacts on cost and magnetic properties from excessive addition.

[0084] Vanadium further enhances the strength and toughness of steel by refining grain size. Vanadium significantly refines grains by forming fine VC carbide particles, thereby improving the material's strength and fatigue resistance. During hot forging and dynamic heat treatment, the precipitation strengthening effect of vanadium helps suppress grain growth, ensuring the uniformity of the microstructure in the rotor billet and heat-treated billet. A content range of 0.1% to 0.25% fully utilizes its grain-refining effect while avoiding excessive addition that could lead to carbide segregation.

[0085] Iron, as the balance component of the base material, forms the main framework of alloy steel. Iron provides excellent machinability and a good foundation for magnetic permeability, working synergistically with other alloying elements to form a well-balanced base material. By precisely controlling the proportions of each element, iron-based alloy steel exhibits excellent adaptability in processes such as hot forging, deposition, and surface strengthening. Optimizing the alloy composition not only meets the requirements of motor rotors for high strength, high toughness, and good thermal stability, but also lays a solid foundation for subsequent processing, ensuring that the final product possesses excellent dynamic balance and durability under high-speed, high-load conditions.

[0086] In one example, the step of hot forging the alloy steel substrate based on a preset forging temperature and then subjecting the hot-forged alloy steel substrate to gradient cooling to obtain a rotor blank includes:

[0087] The alloy steel substrate is preheated to 900-950°C in an inert gas atmosphere to obtain a preheated substrate.

[0088] The preheated substrate is subjected to multi-directional hot forging at a forging frequency of 12 to 18 times per minute and an extrusion angle of 30° to 45° to obtain a preliminary forging billet;

[0089] The initial forging billet is placed in an environment of 700~800℃ and kept for 2 hours. Then, cold air is sprayed onto the outer surface of the initial forging billet to cool it down to 650℃, forming an annealed billet.

[0090] The annealed billet is cooled to 450°C at a rate of 4°C / min using a circulating liquid cooling system. Then, argon gas is injected into the annealed billet at a preset injection angle to assist in cooling it to room temperature, thus obtaining a pre-cooled billet.

[0091] The pre-cooled billet is tempered at 300~350℃ for 2 hours, and the tempered pre-cooled billet is cooled to 150℃ based on a nitrogen circulation system to obtain a fine-tuned billet.

[0092] The fine-tuning billet is cooled to 80°C at a rate of 1.5°C / min, and then the fine-tuning billet is naturally cooled to room temperature to obtain the rotor blank.

[0093] In the above embodiments, the high-strength alloy steel substrate is placed in a multi-stage heating furnace, and the temperature is gradually raised to the preset forging range of 900-950℃ through a zoned temperature control system. The surface and core temperature distribution of the substrate are monitored in real time using an infrared thermometer to ensure that the temperature difference is controlled within ±5℃. At the same time, argon is injected through an inert gas circulation system to maintain a low-oxygen environment and avoid surface oxidation, resulting in a preheated substrate with uniform temperature.

[0094] The preheated substrate is transferred to a multi-directional forging press, and the forging temperature is set to 950-1000℃. Periodic pressure is applied through a multi-axial servo hydraulic system. Stress distribution data during the forging process is collected using a three-dimensional stress sensor. The forging frequency is dynamically adjusted to 12-18 times per minute and the extrusion angle is between 30° and 45° according to the stress distribution. Five rounds of progressive extrusion are performed. After each round of extrusion, the grain morphology is observed through a microscope and the forging path is optimized until the grains are refined into a uniform rod-shaped structure to obtain the initial forged billet.

[0095] The initial forged billet is placed in a vacuum annealing furnace, and the annealing temperature is set to 700~800℃. The temperature field changes inside the billet are monitored by a thermocouple array. Gradient heating technology is used to control the temperature of the billet surface and core in different zones. A small amount of nitrogen is introduced during the annealing process to adjust the surface microstructure. The holding time is set to 2 hours. Then, the temperature is reduced to 650℃ by an inert gas injection system to obtain a stress-released annealed billet.

[0096] The annealed billet is transferred to a multi-stage cooling tank. The temperature gradient control module sets the cooling parameters according to the billet thickness and thermal conductivity characteristics. First, the temperature is reduced to 450°C at a rate of 4°C / min through a circulating water cooling system. Then, the high-pressure argon gas injection mode is switched to assist in cooling the core of the billet. During the cooling process, the temperature distribution is monitored by a thermal imager and the airflow intensity and injection angle are adjusted to obtain a pre-cooled billet with a uniform temperature.

[0097] The pre-cooled billet is placed in a precision heat treatment furnace, and the tempering temperature is set to 300-350℃. The billet is heated in a zoned pulse manner through an electromagnetic induction heating system. The surface temperature change is detected by a laser thermometer. The heating power and holding time are dynamically adjusted according to the temperature data to stabilize the microstructure for 2 hours. Then, the temperature is reduced to 150℃ through a low-temperature nitrogen circulation system to obtain a finely tuned billet with stable structure.

[0098] The finely tuned billet is placed in a programmed cooling device, and a two-stage cooling curve is set through a multi-channel temperature control system. First, the temperature is reduced to 80℃ at a rate of 1.5℃ / min. Then, it is switched to natural cooling mode. The thermal conductivity analyzer is used to collect the internal heat flow data of the billet in real time. The air volume and humidity of the cooling environment are adjusted according to the data to ensure that there are no microcracks on the surface. Finally, the cooling is completed at room temperature to obtain a rotor blank with a uniform microstructure.

[0099] In one example, the step of performing multi-layer gradient cutting on the rotor blank to obtain a cylindrical blank includes:

[0100] The rotor blank is fixed and preheated to 200°C. The outer surface of the preheated rotor blank is rough-cut by 3-5 mm at a speed of 600 rpm to obtain a rough-machined blank.

[0101] The rough-machined blank is subjected to layered peeling and cutting to obtain a layered blank, and the layered blank is then precisely cut at a frequency of 30kHz with ultrasonic assistance to obtain a fine-cut blank.

[0102] The precision-cut blank is dynamically contoured using a coordinate measuring machine to obtain a trimmed blank. The trimmed blank is then tempered at 150°C for 2 hours and then cut to the target size using a precision lathe with a cutting depth of 0.3~0.5 mm to obtain a preformed blank.

[0103] The outer surface of the preformed blank is polished and cut at a preset polishing speed to obtain a cylindrical blank.

[0104] In the above embodiment, the rotor blank is placed in a special fixture and preheated to 200°C to release internal stress. Then, a carbide tool is used to perform initial rough cutting on its outer surface to remove the oxide layer and irregular protrusions of 3-5 mm. During the cutting process, a low-speed rotation mode is used with the rotation speed set at 600 rpm. At the same time, high-pressure coolant is sprayed to cool down and flush away the chips, ensuring that the cutting surface is initially flat, and a rough-machined blank is obtained.

[0105] The rough-machined blank is fixed on a multi-axis lathe, and its outer surface is peeled off layer by layer using a stepped cutting process. The depth of cut is controlled at 1-2 mm for each layer, decreasing from the outside to the inside, approaching the core area. During cutting, the tool angle is manually adjusted and the surface flatness is checked by intermittent machine stops to ensure that there are no obvious cracks or thermal deformation marks after each layer is cut, resulting in a layered blank with a preliminary regular shape. The layered blank is then installed in an ultrasonic vibration cutting device, and the tool is driven to vibrate at a frequency of 30 kHz by an ultrasonic generator to perform precision cutting on its surface. The depth of cut is gradually reduced to 0.8 mm. At the same time, a low-temperature nitrogen gas flow is introduced during the cutting process to reduce the frictional heat effect. Through multiple cycles of cutting and real-time observation of the surface gloss change, until there are no obvious machining marks on the surface, a precision-cut blank with higher dimensional accuracy is obtained.

[0106] The precision-cut blank is placed in a coordinate measuring machine to detect its outer contour geometry. The detection results are used to guide the finishing process. The surface of the precision-cut blank is dynamically finished by a micro grinding wheel. During finishing, the grinding wheel speed and feed are adjusted according to the contour deviation in different areas. The focus is on grinding the local protruding or concave areas multiple times until the overall contour error is controlled within 0.05mm, resulting in a finished blank with a consistent shape.

[0107] The trimmed blank is placed in a low-temperature tempering furnace and held at 150°C for 2 hours to eliminate residual stress. Then it is quickly transferred to a precision lathe for low-temperature cutting. Liquid nitrogen is used to cool the tool and workpiece during cutting to maintain material stability. The cutting depth is controlled at 0.3-0.5mm. The target size is gradually approached through multi-directional rotary cutting to ensure that the cutting surface is smooth and free of microcracks, resulting in a preform blank that is close to a cylindrical shape.

[0108] The preformed blank is fixed in a high-speed polishing machine, and its surface is polished and cut using diamond-coated tools. The polishing speed is set at 1200 rpm and gradually increased to 1500 rpm. At the same time, fine-particle polishing fluid is sprayed to enhance the surface smoothness. Through multiple progressive polishing and combined with optical microscopy to check the surface roughness, the surface achieves a mirror effect and the dimensions fully meet the design requirements, resulting in the final cylindrical blank.

[0109] In one example, the step of performing composite deposition processing on the cylindrical blank based on magnetic materials to obtain a magnetic composite blank includes:

[0110] Based on plasma cleaning equipment The cylindrical blank is bombarded with plasma in the working air pressure to obtain an activated blank;

[0111] The activated billet was subjected to ion carburizing treatment in a mixed gas atmosphere of methane and nitrogen to obtain a carburized billet;

[0112] A primary magnetic blank is obtained by spraying magnetic material onto the carburized billet using a high-frequency plasma arc, and then... The primary magnetic blank is subjected to hot pressing and curing treatment under working air pressure to obtain a cured magnetic blank.

[0113] The solidified magnetic blank is subjected to magnetic field orientation optimization treatment to obtain an oriented magnetic blank, and the surface of the oriented magnetic blank is subjected to plasma polishing treatment using a mixed gas of argon and oxygen as a polishing medium to obtain a magnetic composite blank.

[0114] In the above embodiment, the cylindrical billet is placed in a plasma cleaning device, the working pressure is set to 0.3 Pa, a mixture of argon and hydrogen is used as the plasma source, and high-energy plasma is generated by excitation through a radio frequency power supply to bombard the surface of the cylindrical billet, removing the surface oxide layer and microscopic impurities. At the same time, by controlling the plasma density and processing time, a uniform micro-nano-scale rough structure is formed on the surface of the billet, which enhances the adhesion of the subsequent deposition layer and obtains an activated billet.

[0115] The activated billet is placed in an ion carburizing furnace, with the furnace temperature set at 380℃ and the gas pressure at 0.6Pa. A mixture of methane and nitrogen is introduced through a gas flow controller. Carbon ions are then permeated and deposited on the surface of the activated billet using glow discharge technology, forming a carbide transition layer with a thickness of 0.2-0.3mm on the billet surface. Simultaneously, the carburizing depth and surface hardness are dynamically monitored, and the discharge voltage and gas ratio are adjusted to ensure a tight bond between the transition layer and the substrate, thus obtaining a carburized billet.

[0116] The carburized billet is placed in a plasma spraying device, using a high-frequency plasma arc as the heat source. The spraying temperature is set to 500℃. Pre-ground NdFeB magnetic powder, ground to the micron level, is sprayed onto the surface of the carburized billet via a carrier gas. By controlling the spraying distance and powder supply speed, a primary magnetic coating with a thickness of 0.5-0.7 mm is formed on the surface of the carburized billet. Simultaneously, a cooling system is used to reduce the temperature of the billet itself to avoid the influence of high temperature on the properties of the substrate, thus obtaining the primary magnetic billet. The primary magnetic billet is then placed in a vacuum hot press furnace, with the vacuum level set to... At a temperature of 600℃, a constant pressure is applied to the primary magnetic blank through a hydraulic system. The primary magnetic coating and the carburized layer are further fused by the hot pressing action. At the same time, temperature gradient control and pressure distribution monitoring are used to ensure that the internal grain structure of the coating is densified, eliminating micropores and stress concentration points, and thus obtaining a cured magnetic blank.

[0117] The cured magnetic preform is placed in a magnetic field orientation device, and a uniform strong magnetic field is generated by a superconducting coil. The magnetization distribution data on the surface of the cured magnetic preform is collected in real time by a multi-channel sensor. Based on the collected results, the optimal angle of magnetic field orientation is calculated. Then, an orientation magnetic field is applied and the magnetic field strength is gradually adjusted to make the magnetic domains inside the magnetic coating tend to be consistent. At the same time, the magnetization uniformity is further optimized by rotating the preform and combining it with a pulsed magnetic field to obtain an orientation magnetic preform.

[0118] The directional magnetic blank is placed in a plasma polishing device with a pressure of 0.4 Pa. A mixture of argon and oxygen is used as the polishing medium. The surface of the directional magnetic blank is finely polished by the action of high-energy particles of plasma to remove micro-protrusions and deposition defects. At the same time, by controlling the polishing time and plasma energy, the surface of the magnetic coating is made to achieve mirror-level flatness, and finally a magnetic composite blank is obtained.

[0119] In one example, the step of placing the magnetic composite billet in a vacuum environment for dynamic heat treatment to obtain a heat-treated billet includes:

[0120] exist Under the working air pressure, the magnetic composite blank is first heated to 600°C at a heating rate of 8°C / min and held for 1.5 hours, and then heated to 900°C at a heating rate of 12°C / min and held for 2 hours to obtain a reinforced blank with an enhanced magnetic layer.

[0121] The reinforced billet was cooled to 700°C at a rate of 5°C / min and held for 1 hour, then cooled to 550°C at a rate of 3°C / min and held for 2 hours, and then cooled to 400°C at a rate of 2°C / min and held for 1.5 hours to obtain a lattice-optimized billet.

[0122] A constant magnetic field of 0.5 Tesla is applied to the lattice-optimized billet, and the temperature is raised from 400°C to 650°C at a rate of 5°C / min and held for 1 hour, and then cooled to 300°C at a rate of 4°C / min to obtain a magnetically optimized billet.

[0123] The magnetically optimized billet was cooled to 150°C at a rate of 2°C / min and held for 2.5 hours in an inert gas atmosphere to obtain a stable billet.

[0124] The stabilized billet is cooled to room temperature at a rate of 1.5°C / minute, with a 10-minute pause every 50°C decrease during the cooling process, to obtain a heat-treated billet.

[0125] In the above embodiments, the magnetic composite blank is placed in a vacuum heat treatment furnace, where... Under the working pressure, the billet is gradually heated to 600℃ at a rate of 8℃ / min using a precise temperature control system, and held at this temperature for 1.5 hours. A vacuum environment is used to remove trace gas impurities from the surface of the billet. Simultaneously, a heat conduction analysis module monitors the internal temperature distribution of the billet in real time to ensure uniform heating of the interface between the magnetic material and the substrate, resulting in a preheated billet with preliminary thermal stability. The preheated billet is then placed in a vacuum environment, and the temperature is increased from 600℃ to 900℃ at a rate of 12℃ / min using a dynamic temperature control algorithm, held for 2 hours, and the furnace pressure is periodically adjusted during the holding process. By combining the microscopic deformation data of the billet detected by the thermal expansion monitoring device, the holding time is optimized until the interfacial bonding strength reaches its peak. Then, the temperature is reduced to 700℃ at a rate of 5℃ / minute to obtain a reinforced billet with enhanced magnetic layer structure stability.

[0126] The reinforced billet is placed in a vacuum furnace and subjected to a segmented annealing process. First, the temperature is maintained at 700℃ for 1 hour. Then, it is cooled to 550℃ at a rate of 3℃ / min and held for 2 hours. Next, it is cooled to 400℃ at a rate of 2℃ / min and held for 1.5 hours. The lattice stress change at each stage is recorded using a stress release monitoring system. The cooling rate and holding time are dynamically adjusted based on the stress distribution data to obtain a lattice-optimized billet with optimized crystal structure and uniform internal stress.

[0127] The lattice-optimized billet was placed in a vacuum environment, and a constant magnetic field of 0.5 Tesla was applied by an external magnetic field generator. At the same time, the temperature was raised from 400℃ to 650℃ at a rate of 6℃ / min and held for 1 hour. The molecular orientation of the magnetic material was adjusted by the synergistic effect of the magnetic field and temperature. The magnetic domain distribution of the billet was analyzed in real time by a magnetic induction detection module. Then, the temperature was lowered to 300℃ at a rate of 4℃ / min to obtain a magnetically optimized billet with uniform magnetic properties and consistent orientation.

[0128] The magnetically optimized billet was placed in a vacuum furnace, and the temperature was reduced from 300℃ to 150℃ at a rate of 2℃ / minute using a low-temperature control system. This temperature was maintained for 2.5 hours, and a trace amount of inert gas was introduced during the cooling process to regulate the furnace pressure. By using a thermal conductivity analyzer to monitor the heat flow changes of the billet and optimize the heat preservation time, the thermal stress at the interface between the magnetic layer and the substrate is completely released, resulting in a stable billet with stable structure and enhanced durability.

[0129] The stable billet is kept in a vacuum environment and cooled to room temperature at a rate of 1.5℃ / min using a cooling path planning system. During the cooling process, the cooling rate is adjusted in stages, specifically by pausing for 10 minutes every 50℃ decrease to balance the internal and external temperature difference. At the same time, the residual stress distribution data of the billet is recorded using a stress detection device and the cooling path is optimized. Finally, a heat-treated billet with stable microstructure, excellent magnetic properties, and suitable for subsequent processing is obtained.

[0130] In one embodiment, the step of dynamically balancing the heat-treated billet based on a preset alloy to obtain a balanced rotor includes:

[0131] The heat-treated billet is subjected to initial rotation detection based on a dynamic balancing testing platform to obtain the initial vibration distribution characteristics of the heat-treated billet.

[0132] The initial vibration distribution characteristics are deconstructed by Fourier transform and vector decomposition, the eccentric region of the heat-treated billet is calculated and marked, and the positioning billet is obtained.

[0133] Using plasma spraying equipment, cobalt-based alloy powder is locally pre-deposited onto the positioning billet to obtain a pre-repaired billet.

[0134] The pre-repaired billet is heated to 600°C at a rate of 5°C / min and held for 20 minutes. During the heating process, the pre-repaired billet is simultaneously subjected to vibration at a frequency of 40 kHz to obtain a fine-tuned billet.

[0135] The fine-tuned billet is subjected to secondary balance verification based on the dynamic balance testing platform. The verification results are compared and analyzed with the initial vibration distribution characteristics to generate a residual eccentricity distribution map.

[0136] Based on the residual eccentricity distribution diagram, a nickel-based alloy is locally deposited on the fine-tuning billet by electron beam welding to obtain a dynamically balanced rotor.

[0137] In the above embodiment, the heat-treated billet is fixed on a high-precision dynamic balancing testing platform and rotated initially at a speed of 2500 revolutions per minute. The three-dimensional vibration signal of the billet during the rotation process is collected by a multi-axis accelerometer and a displacement sensor installed on the platform. The sensors record data at a frequency of 1000 times per second. The collected vibration signal is then transmitted to the analysis system. Based on the amplitude and phase distribution of the signal, the initial vibration distribution characteristics of the billet are generated, and the vibration distribution information of the heat-treated billet is obtained.

[0138] The heat-treated billet is placed in a digital modeling system. Using vibration distribution characteristic data, the vibration signal is deconstructed through Fourier transform and vector decomposition techniques to calculate the specific distribution position and magnitude of the eccentric mass of the heat-treated billet on the circumference of the billet. Combined with the three-dimensional geometric model of the billet, the eccentric area is accurately marked on the surface of the billet with a marking accuracy controlled within 0.05 mm. At the same time, the mass deviation value and angular coordinates of each eccentric area are recorded to obtain a positioning billet with eccentric area markings.

[0139] The positioning blank is installed on a precision CNC machining platform. For the marked eccentric area, a pre-set cobalt-based alloy powder is locally deposited onto the eccentric part using a plasma spraying device at a spraying speed of 0.2 mm / s. During the spraying process, the temperature of the sprayed area is monitored in real time by an infrared thermometer and kept between 800 degrees Celsius and 850 degrees Celsius. The deposition thickness is controlled between 0.08 mm and 0.15 mm. The deposited part is then allowed to cool naturally to room temperature to obtain a pre-repaired blank with a pre-deposited alloy layer on the surface.

[0140] The pre-treated billet is placed in a vacuum heat treatment furnace, and the furnace temperature is raised to 600 degrees Celsius at a heating rate of 5°C / min and held for 20 minutes. The thermal expansion effect is used to cause the pre-deposited cobalt-based alloy layer to undergo microscopic bonding with the billet matrix. At the same time, the billet is subjected to vibration at a frequency of 40 kHz by an ultrasonic oscillation device set in the furnace to promote stress release and structural homogenization within the alloy layer. After cooling, the surface of the deposited layer is inspected by an optical microscope to ensure that there are no cracks or pores, resulting in a structurally stable fine-tuned billet.

[0141] The fine-tuned billet was remounted on the dynamic balancing machine and subjected to a second rotation test at a speed of 3500 rpm. The residual eccentricity data of the billet was collected using a laser interferometer and a mass distribution sensor. During the test, the change in eccentricity mass was recorded in units of 0.01 grams. At the same time, a high-speed camera system was used to capture the dynamic deformation of the billet surface. The collected eccentricity data was compared and analyzed with the vibration distribution data of the initial test to generate a residual eccentricity distribution map of the fine-tuned billet.

[0142] The fine-tuning blank is fixed in a five-axis machining center. Based on the residual eccentricity distribution diagram, a diamond-coated milling cutter is used to precisely cut the residual eccentricity on the surface of the blank. The cutting depth is controlled between 0.02 mm and 0.05 mm. During the cutting process, the temperature of the machining area is kept below 50 degrees Celsius by a coolant spray system. Then, a nickel-based alloy is locally deposited in the cut area using an electron beam welding device. The filling thickness is consistent with the cutting depth. After finishing, the blank is placed on a dynamic balancing machine and rotated at 4000 rpm. It is confirmed that the eccentricity is less than 0.005 grams, resulting in a dynamically balanced rotor.

[0143] In one embodiment, the step of performing surface strengthening treatment on the balanced rotor under a nitrogen atmosphere and coating the surface-strengthened balanced rotor with a preset coating to obtain a surface-optimized motor rotor includes:

[0144] The balanced rotor was subjected to ion nitriding treatment under a nitrogen atmosphere to obtain a nitrided rotor.

[0145] The nitrided rotor was immersed in a composite electrolyte for micro-arc oxidation treatment to obtain an oxidation-enhanced rotor. The composite electrolyte contained silicate, phosphate and alumina powder, wherein the concentration of silicate was 20 g / L, the concentration of phosphate was 30 g / L, the concentration of alumina powder was 50 g / L, the voltage of micro-arc oxidation treatment was 450 V, the current density was 8 A / dm², and the oxidation time was 40 minutes.

[0146] Based on plasma spraying equipment, a ceramic coating deposition process is performed on the oxide-strengthened rotor using a preset coating material to obtain a composite coated rotor, wherein the preset coating material includes a mixture of alumina and zirconium oxide powder.

[0147] The surface of the composite coated rotor is subjected to laser remelting treatment to obtain a remelted and strengthened rotor. A high-purity titanium target is used as a deposition source to deposit a metal film on the remelted and strengthened rotor to obtain a rotor with optimized film layer.

[0148] The rotor with optimized film layer is coated with a fluorinated polyurethane pre-coating at low temperature to obtain a motor rotor with optimized surface.

[0149] In the above embodiment, the balancing rotor was placed in an ion nitriding furnace and subjected to ion nitriding treatment under a nitrogen atmosphere to obtain a nitrided rotor. During the treatment, the furnace temperature was set to 480°C, the gas pressure was maintained at 0.7 Pa, and nitrogen gas with a purity of 99.99% was introduced. Nitrogen atoms were penetrated into the surface of the balancing rotor through ion bombardment. The nitriding time was set to 5 hours. During this period, the gas pressure was dynamically adjusted according to the thermal expansion characteristics of the rotor material. The surface nitrogen atom concentration was detected every hour, and the diffusion depth data was recorded. Finally, a nitrided layer with a thickness of 0.06 mm was formed. The surface of the nitrided rotor showed a uniform nitride distribution, providing a basis for subsequent strengthening.

[0150] A nitrided rotor was immersed in a composite electrolyte containing silicate, phosphate, and alumina for micro-arc oxidation treatment, resulting in an oxide-reinforced rotor. The silicate concentration was 20 g / L, the phosphate concentration was 30 g / L, and the alumina powder concentration was 50 g / L. During the treatment, a pulsed power supply was used, with the voltage controlled at 450 V, the current density set at 8 A / dm², and the electrolyte temperature maintained at 30 °C. A dense oxide ceramic layer was generated on the surface of the nitrided rotor through micro-arc discharge. The oxidation time lasted for 40 minutes, during which the pulse frequency was adjusted according to changes in the rotor surface conductivity to ensure that the oxide layer thickness reached 0.03 mm. This further enhanced the surface hardness and wear resistance of the oxide-reinforced rotor.

[0151] An anodized rotor was placed in a plasma spraying device, and a ceramic coating was deposited on the rotor according to its surface morphology to obtain a composite-coated rotor. During the spraying process, a mixture of alumina and zirconium oxide powder was used as the pre-set coating material. The spraying temperature was controlled at 12000℃ in a plasma flame, the distance between the spray gun and the rotor surface was set to 100mm, the spraying angle was dynamically adjusted according to the rotor curvature, and the coating deposition time was 15 minutes. Deposition parameters were optimized by monitoring the flame velocity and the melting state of the powder particles, ultimately forming a 0.025mm thick ceramic coating on the surface of the anodized rotor. The composite-coated rotor exhibits higher heat resistance and corrosion resistance.

[0152] A composite-coated rotor was subjected to laser surface remelting under a high-power laser device to obtain a remelted and strengthened rotor. During the process, a pulsed laser with a wavelength of 1064 nm and a power of 2 kW was used. The laser beam moved along the rotor surface at a scanning speed of 0.5 mm / s. By precisely controlling the focal length, the laser energy was concentrated on the coating surface, inducing localized melting and rapid solidification of the coating. The remelting time was 10 minutes, during which the laser pulse width was adjusted according to the rotor surface reflectivity. Ultimately, micropores in the coating were eliminated, and the surface smoothness and bonding strength of the remelted and strengthened rotor were significantly optimized. The remelted and strengthened rotor was then fixed in a magnetron sputtering device, and metal film deposition was performed based on the surface characteristics of the remelted and strengthened rotor to obtain a rotor with optimized film layer. High-purity titanium target material was selected as the deposition source, sputtering power was set to 300W, working pressure was controlled at 0.5Pa, and reactive sputtering was carried out in a mixed atmosphere of nitrogen and argon. The deposition time was 20 minutes. The relative position of the target material and the rotor was adjusted by real-time monitoring of the film growth rate and rotor surface temperature. Finally, a titanium nitride film layer with a thickness of 0.01mm was formed on the surface of the remelted and strengthened rotor. The film layer optimized the rotor surface and exhibited excellent oxidation resistance and wear resistance.

[0153] The film-optimized rotor was placed in a coating equipment and subjected to low-temperature curing coating treatment to obtain a surface-optimized motor rotor. During the coating process, a pre-prepared fluorinated polyurethane coating was used. The spraying equipment moved along the rotor axis at a speed of 0.3 m / s, and the coating thickness was controlled at 0.015 mm. After coating, the rotor was placed in a nitrogen-protected environment at 80°C for curing for 2 hours. During this time, the rotor surface temperature was monitored using an infrared thermometer, and the ventilation rate of the curing oven was adjusted to ensure complete bonding between the coating and the film-optimized rotor surface. The result was a surface-optimized motor rotor with excellent weather resistance and protective properties.

[0154] refer to Figure 2 and Figure 3 The present invention also provides a motor rotor, which adopts the processing method of the motor rotor as described in any of the above claims, including a shaft 1 and a core 2, wherein the core 2 is sleeved on the outside of the shaft 1, the shaft 1 is provided with an elliptical fixing groove 101 along the axial direction, and the core 2 is fixedly connected to the shaft 1 through the fixing groove 101.

[0155] The outer surface of the core 2 is covered with a magnetic composite layer. A plurality of magnetic pole units 3 are embedded in the outer surface of the magnetic composite layer along the circumferential direction. The cross-section of the magnetic pole unit 3 is trapezoidal, and an isolation strip is provided between two adjacent magnetic pole units 3.

[0156] In the above embodiment, the core 2 is sleeved on the outside of the shaft 1, forming a stable structural foundation. The shaft 1 has an elliptical fixing groove 101 designed along its axial direction. The elliptical design of the fixing groove 101 increases the contact area and geometric fit, allowing the core 2 to be firmly fixed to the shaft 1 through the fixing groove 101, effectively preventing relative slippage during rotation and improving the overall structural stability. The outer surface of the core 2 is covered with a magnetic composite layer made of a high-permeability material, which enhances the magnetic field strength and optimizes the magnetic flux distribution. Several magnetic pole units 3 are embedded circumferentially on its outer surface. The cross-section of the magnetic pole unit 3 is trapezoidal, which not only facilitates processing and installation but also effectively concentrates magnetic lines of force, improving magnetic efficiency. The isolation strips between adjacent magnetic pole units 3 are made of non-magnetic material to reduce magnetic field interference, ensuring that each magnetic pole unit 3 operates independently, thereby improving the motor's operating efficiency and output power.

[0157] The synergistic effect of the elliptical fixing slot 101 and the trapezoidal magnetic pole unit 3 significantly improves the mechanical strength and magnetic properties of the motor rotor. The elliptical design of the fixing slot 101 can evenly distribute stress under high speeds, avoiding local fatigue failure; while the combination of the magnetic composite layer and the trapezoidal magnetic pole unit 3 optimizes the magnetic field distribution, reduces energy loss, and enables the motor to maintain excellent performance under high load conditions. In addition, the isolation strip further reduces crosstalk between magnetic poles, providing the motor with higher stability and durability, making it suitable for industrial scenarios requiring high-efficiency output.

[0158] In one embodiment, the core 2 is provided with a balance reinforcing ring 4 at opposite ends, and the balance reinforcing ring 4 is provided with a plurality of balance holes 401 along the axial direction, and the balance holes 401 are coated with a counterweight alloy layer.

[0159] In the above embodiment, the balancing reinforcement rings 4 at both ends of the core 2 of the motor rotor are made of high-strength material, and have several balancing holes 401 along the axial direction. The structural performance is further optimized by coating the balancing holes 401 with a counterweight alloy layer. The main function of the balancing reinforcement rings 4 is to enhance the rigidity and stability of the ends of the core 2. Its ring structure can effectively resist the centrifugal force when the rotor rotates at high speed, preventing end deformation or cracking. The axially distributed balancing holes 401 reduce the overall weight of the rotor and provide space for dynamic balance adjustment. The inner wall of the balancing holes 401 is coated with a counterweight alloy layer, which uses an alloy material with adjustable density (such as cobalt-based or tungsten-based alloy). By controlling the coating thickness and distribution, the mass distribution of the rotor can be precisely adjusted, significantly reducing vibration and noise during operation and improving the dynamic balance performance of the rotor.

[0160] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for machining an electric motor rotor, characterized in that, include: The alloy steel substrate is hot-forged based on a preset forging temperature, and then the hot-forged alloy steel substrate is subjected to gradient cooling treatment to obtain the rotor blank. The rotor blank is subjected to multi-layer gradient cutting to obtain a cylindrical blank; A magnetic composite billet is obtained by performing a composite deposition process on the cylindrical billet based on magnetic materials. The magnetic composite blank is placed in a vacuum environment for dynamic heat treatment to obtain a heat-treated blank. The heat-treated billet is dynamically balanced and trimmed based on a preset alloy to obtain a balanced rotor. The balanced rotor is subjected to surface strengthening treatment under a nitrogen atmosphere, and the surface-strengthened balanced rotor is coated with a preset coating to obtain a motor rotor with optimized surface. The steps of hot forging the alloy steel substrate based on a preset forging temperature and then subjecting the hot-forged alloy steel substrate to gradient cooling to obtain the rotor blank include: The alloy steel substrate is preheated to 900-950°C in an inert gas atmosphere to obtain a preheated substrate. The preheated substrate is subjected to multi-directional hot forging at a forging frequency of 12 to 18 times per minute and an extrusion angle of 30° to 45° to obtain a preliminary forging billet; The initial forging billet is placed in an environment of 700~800℃ and kept for 2 hours. Then, cold air is sprayed onto the outer surface of the initial forging billet to cool it down to 650℃, forming an annealed billet. The annealed billet is cooled to 450°C at a rate of 4°C / min using a circulating liquid cooling system. Then, argon gas is injected into the annealed billet at a preset injection angle to assist in cooling it to room temperature, thus obtaining a pre-cooled billet. The pre-cooled billet is tempered at 300~350℃ for 2 hours, and the tempered pre-cooled billet is cooled to 150℃ based on a nitrogen circulation system to obtain a fine-tuned billet. The fine-tuning billet is cooled to 80°C at a rate of 1.5°C / min, and then the fine-tuning billet is naturally cooled to room temperature to obtain the rotor blank.

2. The method for processing a motor rotor according to claim 1, characterized in that, The alloy steel substrate is a mixture of chromium, molybdenum, carbon, nickel, vanadium and iron. In the alloy steel substrate, the percentage of chromium by mass is 1.5-3%, the percentage of molybdenum is 0.5-1.2%, the percentage of carbon is 0.3-0.6%, the percentage of nickel is 0.8-1.5%, the percentage of vanadium is 0.1-0.25%, and the balance is iron.

3. The method for processing a motor rotor according to claim 1, characterized in that, The step of performing multi-layer gradient cutting on the rotor blank to obtain a cylindrical blank includes: The rotor blank is fixed and preheated to 200°C. The outer surface of the preheated rotor blank is rough-cut by 3-5 mm at a speed of 600 rpm to obtain a rough-machined blank. The rough-machined blank is subjected to layered peeling and cutting to obtain a layered blank, and the layered blank is then precisely cut at a frequency of 30kHz with ultrasonic assistance to obtain a fine-cut blank. The precision-cut blank is dynamically contoured using a coordinate measuring machine to obtain a trimmed blank. The trimmed blank is then tempered at 150°C for 2 hours and then cut to the target size using a precision lathe with a cutting depth of 0.3~0.5 mm to obtain a preformed blank. The outer surface of the preformed blank is polished and cut at a preset polishing speed to obtain a cylindrical blank.

4. The method for processing a motor rotor according to claim 1, characterized in that, The step of performing composite deposition processing on the cylindrical blank based on magnetic materials to obtain a magnetic composite blank includes: Based on plasma cleaning equipment The cylindrical blank is bombarded with plasma in the working air pressure to obtain an activated blank; The activated billet was subjected to ion carburizing treatment in a mixed gas atmosphere of methane and nitrogen to obtain a carburized billet; A primary magnetic blank is obtained by spraying magnetic material onto the carburized billet using a high-frequency plasma arc, and then... The primary magnetic blank is subjected to hot pressing and curing treatment under working air pressure to obtain a cured magnetic blank. The solidified magnetic blank is subjected to magnetic field orientation optimization treatment to obtain an oriented magnetic blank, and the surface of the oriented magnetic blank is subjected to plasma polishing treatment using a mixed gas of argon and oxygen as a polishing medium to obtain a magnetic composite blank.

5. The method for processing a motor rotor according to claim 1, characterized in that, The step of placing the magnetic composite blank in a vacuum environment for dynamic heat treatment to obtain a heat-treated blank includes: exist Under the working air pressure, the magnetic composite blank is first heated to 600°C at a heating rate of 8°C / min and held for 1.5 hours, and then heated to 900°C at a heating rate of 12°C / min and held for 2 hours to obtain a reinforced blank with an enhanced magnetic layer. The reinforced billet was cooled to 700°C at a rate of 5°C / min and held for 1 hour, then cooled to 550°C at a rate of 3°C / min and held for 2 hours, and then cooled to 400°C at a rate of 2°C / min and held for 1.5 hours to obtain a lattice-optimized billet. A constant magnetic field of 0.5 Tesla is applied to the lattice-optimized billet, and the temperature is raised from 400°C to 650°C at a rate of 5°C / min and held for 1 hour, and then cooled to 300°C at a rate of 4°C / min to obtain a magnetically optimized billet. The magnetically optimized billet was cooled to 150°C at a rate of 2°C / min and held for 2.5 hours in an inert gas atmosphere to obtain a stable billet. The stabilized billet is cooled to room temperature at a rate of 1.5°C / minute, with a 10-minute pause every 50°C decrease during the cooling process, to obtain a heat-treated billet.

6. The method for processing a motor rotor according to claim 1, characterized in that, The step of dynamically balancing and trimming the heat-treated billet based on a preset alloy to obtain a balanced rotor includes: The heat-treated billet is subjected to initial rotation detection based on a dynamic balancing testing platform to obtain the initial vibration distribution characteristics of the heat-treated billet. The initial vibration distribution characteristics are deconstructed by Fourier transform and vector decomposition, the eccentric region of the heat-treated billet is calculated and marked, and the positioning billet is obtained. Using plasma spraying equipment, cobalt-based alloy powder is locally pre-deposited onto the positioning billet to obtain a pre-repaired billet. The pre-repaired billet is heated to 600°C at a rate of 5°C / min and held for 20 minutes. During the heating process, the pre-repaired billet is simultaneously subjected to vibration at a frequency of 40 kHz to obtain a fine-tuned billet. The fine-tuned billet is subjected to secondary balance verification based on the dynamic balance testing platform. The verification results are compared and analyzed with the initial vibration distribution characteristics to generate a residual eccentricity distribution map. Based on the residual eccentricity distribution diagram, a nickel-based alloy is locally deposited on the fine-tuning billet by electron beam welding to obtain a dynamically balanced rotor.

7. The method for processing a motor rotor according to claim 1, characterized in that, The step of performing surface strengthening treatment on the balanced rotor under a nitrogen atmosphere and coating the surface-strengthened balanced rotor with a preset coating to obtain a surface-optimized motor rotor includes: The balanced rotor was subjected to ion nitriding treatment under a nitrogen atmosphere to obtain a nitrided rotor. The nitrided rotor was immersed in a composite electrolyte for micro-arc oxidation treatment to obtain an oxidation-enhanced rotor. The composite electrolyte contained silicate, phosphate and alumina powder, wherein the concentration of silicate was 20 g / L, the concentration of phosphate was 30 g / L, the concentration of alumina powder was 50 g / L, the voltage of micro-arc oxidation treatment was 450 V, the current density was 8 A / dm², and the oxidation time was 40 minutes. Based on plasma spraying equipment, a ceramic coating deposition process is performed on the oxide-strengthened rotor using a preset coating material to obtain a composite coated rotor, wherein the preset coating material includes a mixture of alumina and zirconium oxide powder. The surface of the composite coated rotor is subjected to laser remelting treatment to obtain a remelted and strengthened rotor. A high-purity titanium target is used as a deposition source to deposit a metal film on the remelted and strengthened rotor to obtain a rotor with optimized film layer. The rotor with the film layer optimized by low-temperature curing coating is based on a fluorinated polyurethane pre-coating to obtain a motor rotor with optimized surface.

8. A motor rotor, characterized in that, The method for processing a motor rotor according to any one of claims 1-7 includes a shaft and a core, wherein the core is sleeved on the outside of the shaft, the shaft is provided with an elliptical fixing groove along the axial direction, and the core is fixedly connected to the shaft through the fixing groove; The outer surface of the core is covered with a magnetic composite layer, and a plurality of magnetic pole units are embedded in the outer surface of the magnetic composite layer along the circumferential direction. The cross-section of the magnetic pole unit is trapezoidal, and an isolation strip is provided between two adjacent magnetic pole units.

9. A motor rotor according to claim 8, characterized in that, The core has a balance reinforcement ring at each of its two opposite ends. The balance reinforcement ring has a plurality of balance holes along the axial direction and the balance holes are coated with a counterweight alloy layer.

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