Electromagnetic centrifuge apparatus and method for a motor rotor

Abstract

The application discloses a motor rotor electromagnetic centrifugal device and method, comprising a centrifugal force simulation module for simulating high-speed rotation centrifugal force of a rotor and a stress release module for releasing residual stress of a rotor core; the centrifugal force simulation module comprises a winding core and an electromagnetic force winding wound on the winding core, the winding core is arranged around a rotor assembly and is arranged in correspondence with a magnetic steel on the rotor assembly, an electromagnetic force is applied to the magnetic steel in a radial outward direction through electrification of the electromagnetic force winding, and the magnetic steel is displaced along a bonding interface; an induction heating coil is coaxially arranged around the rotor assembly, and the induction heating coil acts on the rotor assembly, so that a stress threshold of the rotor core material is reduced, residual machining and assembly stress inside the rotor core is released, traditional high-speed rotation test is replaced, safety hazards of high-priced equipment investment and high-speed operation are avoided, complex debugging is not needed, test cost and operation difficulty are greatly reduced, and batch production requirements are met.

Description

Technical Field

[0001] This application belongs to the field of motor rotor testing equipment, and in particular relates to an electromagnetic centrifuge device and method for motor rotor. Background Technology

[0002] The rotor assembly of the drive motor for new energy vehicles is mainly composed of a rotating shaft, a stacked rotor core, permanent magnets, and magnet adhesive, and is the core rotating component for motor power output.

[0003] After a period of operation, or after completing a vehicle durability and reliability test, the original stress structure inside the rotor of a car drive motor gradually changes. Combined with the long-term effect of centrifugal cyclic loads, the residual processing and assembly stresses within the rotor core laminations are continuously released, causing slight deformation of the core. Simultaneously, under the combined effects of alternating centrifugal force and thermal expansion and contraction, the bonding interface of the magnets experiences slight slippage and displacement, altering their relative installation position. This misalignment of the rotor's center of mass with its rotation axis generates periodic eccentric centrifugal force during rotation, directly causing a deterioration in rotor dynamic balance. This, in turn, leads to increased generator vibration, excessive operating noise, accelerated bearing wear, shortened motor lifespan, and impacts overall vehicle performance and reliability.

[0004] The current industry-standard solution involves high-speed overspeed testing of the rotor. This utilizes the high rotational speed to generate a massive centrifugal load, causing the residual stress inside the rotor core to be released prematurely and completely. Simultaneously, it simulates the centrifugal conditions of a vehicle operating for extended periods, leading to earlier stable displacement of the magnets and completing stress release and pre-determining of the magnets' posture. After the rotor's structural deformation and positional changes have stabilized, dynamic balancing testing and weight adjustments are then performed to ensure the rotor's dynamic balance remains stable and controllable after long-term service, effectively preventing later imbalances, abnormal noises, and vibration failures.

[0005] However, existing overspeed pretreatment processes have significant shortcomings in mass production applications: the purchase cost of dedicated high-speed overspeed testing equipment for rotors can reach several million yuan, placing a huge burden on enterprises' fixed asset investment; outsourcing overspeed testing to external third-party organizations results in high costs per test, long testing cycles, and cumbersome workflow management, making it unsuitable for the large-scale mass production pace of automotive motors and difficult to cover the rotor pretreatment process across all batches. The industry lacks a low-cost, high-efficiency rotor stress pre-release and dynamic balancing long-term stable process suitable for assembly line mass production, which has long constrained the improvement of reliability and optimization of production costs for new energy motor rotors, becoming a technical problem that the industry urgently needs to solve. Summary of the Invention

[0006] The present invention provides an electromagnetic centrifuge device and method for an electric motor rotor, which at least solves or alleviates one or more technical problems in the prior art, or at least provides a beneficial alternative.

[0007] To achieve the above objectives, the present invention provides the following technical solution: An electromagnetic centrifugal device for an electric motor rotor includes a centrifugal force simulation module for simulating the centrifugal force of a rotor rotating at high speed and a stress relief module for releasing the residual stress in the rotor core. The centrifugal force simulation module includes a winding core and an electromagnetic force winding wound around the winding core. The winding core is arranged around the rotor assembly and is correspondingly set with the magnets on the rotor assembly. By energizing the electromagnetic force winding, a radially outward electromagnetic force is applied to the magnets, causing the magnets to displace along the bonding interface. The stress relief module is equipped with an induction heating coil that can be adjusted up and down. The induction heating coil is arranged coaxially around the rotor assembly. It acts on the rotor assembly through induction heating to reduce the stress threshold of the rotor core material and promote the release of residual processing and assembly stress inside the rotor core.

[0008] In a preferred embodiment, the outer end of the winding core is assembled to the outer ring of the winding core through a fixed structure, the outer ring of the winding core is installed on the upper end of the support base, the rotor support disk is coaxially arranged at the center of the support base, and the rotor assembly is coaxially positioned and installed at the center of the rotor support disk.

[0009] In a preferred embodiment, the outer ring of the winding core is made of a non-magnetic material, a circumferential magnetic shield is fixedly installed between adjacent winding cores, and an axial magnetic shield is provided at both the upper and lower ends of the winding core; the winding core retains a magnetic working surface only on the side facing the rotor magnet.

[0010] In a preferred implementation, a control system and an adjustable output power supply are also included. The adjustable output power supply is electrically connected to the centrifugal force simulation module. The magnitude of the electromagnetic force is changed by changing the output current of the electromagnetic force winding through the control system.

[0011] In a preferred embodiment, the outer ring of the winding core is composed of multiple sets of independent arc plates, each arc plate is radially slidably assembled on the upper end of the support base and connected to a radial moving mechanism; the control system synchronously controls the radial moving mechanism to move and adjust the distance between the winding core and the rotor magnet according to the magnitude of the excitation current.

[0012] In the preferred implementation, the circumferential magnetic shielding plate and the upper and lower axial magnetic shielding plates are both fixedly connected to the corresponding arc-shaped plates and move radially synchronously with the arc-shaped plates.

[0013] In a preferred implementation, the radial movement mechanism includes a servo drive component connected to an arc-shaped plate, which drives the arc-shaped plate to move radially reciprocatingly.

[0014] In a preferred embodiment, the induction heating coil is connected to a coil base, and the coil base is connected to a lifting mechanism; the lifting mechanism drives the coil base to move vertically up and down, causing the electromagnetic heating coil to extend into or move out of the annular gap between the rotor assembly and the winding core.

[0015] In the preferred implementation, a temperature detection probe is arranged inside the heating cylinder, and the induction heating coil is connected to a parameterized temperature control system. Before the test, the rotor diameter and permanent magnet specifications are input. The temperature control system matches the critical demagnetization temperature of the magnet and sets the upper limit threshold for heating. The heating power and heating time are controlled in a closed loop to prevent the magnet from losing magnetism at high temperatures.

[0016] The method of using the electromagnetic centrifuge with motor rotor includes the following steps: S1. Pre-processing test: The rotor assembly is placed in the rotor dynamic balancing equipment for initial dynamic balancing test. The initial dynamic balance value of the rotor assembly is accurately measured and recorded as a reference for subsequent comparison. S2. Rotor positioning and installation: Assemble the rotor assembly, which has completed the initial test, in the center of the equipment, so that each magnet on the rotor assembly corresponds to each winding core of the equipment to ensure the subsequent electromagnetic force. S3. Heating treatment: The drive coil base and the heating cylinder connected to it descend vertically, so that the heating cylinder extends into the annular gap between the rotor assembly and the winding core; the induction heating coil is started, and according to the pre-input rotor diameter and permanent magnet specifications, the temperature control system automatically matches the critical demagnetization temperature of the magnet and sets the upper limit threshold of heating, controlling the induction heating coil to heat the rotor assembly according to the set temperature and heating time, thus completing the core stress pretreatment; S4. Electromagnetic centrifugal simulation: After heating is completed, the drive coil base and heating cylinder are raised vertically, so that the heating cylinder moves out of the annular gap; the excitation system of the winding core is started, and the excitation current is adjusted according to the preset centrifugal force parameters to apply radial outward electromagnetic centrifugal force to the rotor assembly, maintain the electromagnetic centrifugal force for a preset duration, and simulate the centrifugal force condition when the rotor is running at high speed. S5. Secondary dynamic balancing test: After the electromagnetic centrifugal simulation is completed, the excitation system is turned off, the rotor assembly is removed, and it is placed in the rotor dynamic balancing equipment again for dynamic balancing test. The dynamic balancing values ​​are accurately measured and recorded. S6. Cyclic Detection: Repeat steps S3 to S5 to continuously heat, simulate electromagnetic centrifugation, and perform dynamic balance detection on the rotor assembly until the continuously measured dynamic balance values ​​tend to stabilize without significant fluctuations. S7. Dynamic Balance Correction: Based on the stable dynamic balance values ​​in step S6, perform dynamic balance correction on the rotor assembly to ensure that the dynamic balance accuracy of the rotor assembly reaches the preset standard.

[0017] The above structure has the following beneficial effects: The electromagnetic centrifugal device for motor rotors in this application replaces traditional high-speed rotation testing with electromagnetic simulation, avoiding the risks of high-cost equipment investment and high-speed operation. At the same time, it eliminates the need for complex debugging, significantly reducing testing costs and operational difficulty, and is suitable for mass production needs.

[0018] The electromagnetic centrifuge device for motor rotors in this application avoids magnetic field crosstalk through magnetic shielding design and precise current adjustment, ensuring that the electromagnetic force acts precisely on the target magnet without any extra lateral force interference. At the same time, it can flexibly adapt to the centrifugal force requirements corresponding to different speeds, and the simulation effect is consistent with the real high-speed rotation conditions. Moreover, it is easier to control than the traditional method.

[0019] The electromagnetic centrifugal device for motor rotors in this application releases internal stress in advance through heating pretreatment and force control, stabilizes the position of magnets and iron core, avoids vibration and abnormal noise caused by stress accumulation and position displacement in the later stage, extends the service life of motor, and is compatible with rotors of different specifications, with strong versatility. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and, together with their description, serve to explain this application and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic structural diagram of one embodiment of the electromagnetic centrifugal device for motor rotors in this application.

[0021] Figure 2 This is a three-dimensional structural diagram of the centrifugation simulation module of this application.

[0022] Figure 3 This is a top view of the centrifugation simulation module of this application.

[0023] Figure 4 This is a schematic diagram of the structure of the centrifugal simulation module of this application, which includes a circumferential magnetic shield and a circumferential magnetic shield.

[0024] Figure 5 This is a schematic diagram of the structure of the arc-shaped plate connected to the servo drive component in this application.

[0025] Label Explanation: 1. Centrifugal force simulation module; 10. Winding core; 11. Electromagnetic force winding; 2. Stress relief module; 20. Induction heating coil; 21. Coil base; 22. Lifting mechanism; 3. Winding core outer ring; 30. Arc plate; 4. Support base; 40. Rotor support plate; 5. Control system; 6. Circumferential magnetic shielding plate; 7. Axial magnetic shielding plate; 80. Magnet; 81. Rotating shaft; 9. Servo drive component. Detailed Implementation

[0026] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit and scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0027] The present invention will now be described with reference to the accompanying drawings.

[0028] The specific solution adopted is as follows: like Figure 1-5 As shown, the present invention provides an electromagnetic centrifugal device for an electric motor rotor, including a centrifugal force simulation module 1 for simulating the centrifugal force of the rotor rotating at high speed and a stress relief module 2 for releasing the residual stress of the rotor core. The centrifugal force simulation module 1 includes a winding core 10 and an electromagnetic force winding 11 wound on the winding core 10. The winding core 10 is arranged around the rotor assembly and is correspondingly set with the magnet 80 on the rotor assembly. By energizing the electromagnetic force winding 11, a radially outward electromagnetic force is applied to the magnet 80, causing the magnet 80 to be displaced along the bonding interface. The stress relief module 2 is equipped with an induction heating coil 20 that can be adjusted up and down. The induction heating coil 20 is arranged coaxially around the rotor assembly. It acts on the rotor assembly through induction heating to reduce the stress threshold of the rotor core material and promote the release of residual processing and assembly stress inside the rotor core.

[0029] This invention employs a design that combines electromagnetic simulation of centrifugal force with induction heating stress release to achieve a static operating condition replacement for a dynamic high-speed operating condition. The specific principle is as follows: Under actual high-speed rotation conditions, the rotor's force and stress release mechanism is as follows: the centrifugal force generated by high-speed rotation is distributed radially outward. This tension directly acts on the rotor core and permanent magnet 80, forcing the magnet 80 to move within a preset range along the bonding interface with the core. At the same time, the continuous centrifugal load during high-speed rotation will gradually excite the residual processing stress and assembly stress inside the rotor core, causing them to be released slowly. This allows the relative position of the magnet 80 and the core to gradually stabilize, avoiding positional deviation and dynamic imbalance caused by operation in later stages.

[0030] On the one hand, this application generates a radially outward electromagnetic force by passing current through the winding core 10, which is arranged around the rotor assembly and corresponds one-to-one with the magnet 80, after the winding coil is energized. The direction of this electromagnetic force is consistent with the direction of the centrifugal force when the rotor is rotating at high speed, and the magnitude of the electromagnetic force can be flexibly adjusted by adjusting the current parameters to match the magnitude of the centrifugal force corresponding to different high-speed rotor speeds, thereby achieving equivalent traction on the magnet 80 and achieving the same displacement driving effect as the real centrifugal force. On the other hand, regarding the stress release process under high-speed rotation conditions, this application abandons the stress excitation method brought about by dynamic rotation and uses an induction heating coil 20 to preheat the rotor core. By reducing the stress threshold of the rotor core material through induction heating, the residual processing and assembly stress inside the core can be fully released in advance without relying on the centrifugal load of high-speed rotation. At the same time, with the continuous action of the electromagnetic force, the bonding interface between the magnet 80 and the core completes stress release and position stabilization in advance, ultimately achieving a stress release effect and position stabilization purpose that is basically the same as under the high-speed rotation conditions of the rotor.

[0031] The electromagnetic centrifugal equipment for motor rotors using this application will significantly reduce enterprises' fixed asset investment and testing costs, adapt to the needs of large-scale mass production, and solve the industry pain points of long third-party testing cycles and high costs. By simulating centrifugal loads with electromagnetic force and releasing residual stress in advance with induction heating, the position and stress state of the rotor core and magnet 80 are kept stable in the long term, avoiding problems such as dynamic balance deviation, vibration and noise in later operation, and improving the reliability of motor rotor operation.

[0032] See Figure 1 and Figure 2 The outer end of the winding core 10 is assembled to the outer ring 3 of the winding core through a fixed structure. The fixed structure is a dovetail groove structure. The outer end of the winding core 10 is fixed to the outer ring 3 of the winding core through the dovetail groove structure. The outer ring 3 of the winding core is installed on the upper end of the support base 4. The rotor support disk 40 is coaxially set at the center of the support base 4. The rotor assembly is coaxially positioned and installed at the center of the rotor support disk 40.

[0033] When the outer diameter of the rotor changes, only the induction heating coil 20 and the outer ring 3 of the winding core need to be replaced. When the diameter of the rotor shaft changes, only the rotor support plate 40 needs to be replaced. The electric heating temperature can be adjusted by changing the current magnitude and energizing time in the induction heating coil 20; The magnitude and direction of the electromagnetic force can be adjusted by changing the magnitude and direction of the current in the electromagnetic force winding 11; Both electric heating and electromagnetic force are generated quickly and can be applied repeatedly in a short period of time to achieve the desired effect without affecting the production cycle. It can be adapted to different rotor specifications without complicated modifications and can be flexibly adjusted according to the rotor model and magnet parameters. It can also be adapted to the motor rotor pretreatment of different vehicle models, making it highly versatile.

[0034] As a preferred embodiment of this application, the outer ring 3 of the winding core is made of a non-magnetic material, and a circumferential magnetic shielding plate 6 is fixedly installed between adjacent winding cores 10. An axial magnetic shielding plate 7 is provided at both the upper and lower ends of the winding core 10. The winding core 10 retains a magnetic working surface only on the side facing the rotor magnet 80.

[0035] Regarding the influence of adjacent winding cores 10, each adjacent winding core 10 generates its own magnetic field after being energized. Without the circumferential magnetic shielding plate 6, the magnetic fields of two adjacent cores will affect each other, resulting in inconsistent magnetic field strengths for each core. This leads to uneven electromagnetic forces on the corresponding magnets 80, with some magnets 80 experiencing excessive forces while others experience insufficient forces, making it impossible to simulate uniform centrifugal force and ultimately causing the rotor dynamic balancing pretreatment to fail. By setting the circumferential magnetic shielding plate 6, the magnetic field of each winding core 10 can be firmly confined within its own range, preventing interference between adjacent magnetic fields and ensuring consistent magnetic field strength across all winding cores 10, resulting in uniform forces on the corresponding magnets 80.

[0036] Regarding the influence in the vertical direction, if there are no axial magnetic shielding plates 7 at the top and bottom ends of the winding core 10, the magnetic field will leak out along the vertical direction, which will weaken the effective magnetic force acting on the magnet 80. After setting the axial magnetic shielding plates 7, the leakage magnetic path in the vertical direction can be blocked, so that the magnetic force is concentrated on the side facing the magnet 80, ensuring that the effective magnetic force is sufficient and stable. Similarly, regarding the influence of the outer ring 3 of the winding core: if the outer ring 3 of the winding core is made of a magnetically conductive material, it will become a path for the magnetic field, causing the magnetic field of each winding core 10 to pass through the outer ring. This will not only cause leakage magnetic force and weaken the effective magnetic force, but also prevent all winding cores 10 from maintaining their independent and consistent force output. After using a non-magnetically conductive material, the magnetic field can be blocked from being conducted through the outer ring, avoiding magnetic field crosstalk and displacement, and ensuring that each winding core 10 works independently and is subjected to consistent force.

[0037] By retaining magnetic conduction only on the side facing the magnet 80, the magnetic field can be directed entirely to the corresponding magnet 80, ensuring the targeting and consistency of the magnetic force, eliminating ineffective magnetic leakage, and ensuring that the electromagnetic force is accurately applied to the magnet 80, which meets the radial output requirements of centrifugal force.

[0038] The non-magnetic outer ring, the circumferential magnetic shielding plate 6, and the axial magnetic shielding plate 7 can be made of materials such as aluminum alloy or magnetic shielding ceramic.

[0039] As a preferred embodiment of this application, it also includes a control system 5 and an adjustable output power supply. The adjustable output power supply is electrically connected to the centrifugal force simulation module 1. The output current of the electromagnetic force winding 11 is changed by the control system 5, thereby changing the magnitude of the electromagnetic force. The output current is adjusted according to actual needs. Combined with the control system 5 to regulate the electromagnetic output of the winding, the magnitude of the centrifugal force corresponding to different rotation speeds is simulated. The electromagnetic force intensity can be adjusted at any time according to the test needs. Simulation of different centrifugal loads can be achieved without relying on high-speed rotation, improving the adaptability and flexibility of the equipment and facilitating the batch production of rotor pretreatment work.

[0040] Furthermore, on the same radial line, there are two sets of magnets 80A and B. The core 10 of winding A should ideally only pull the inner magnet 80A. However, if the magnetic field extends, it will also exert a pulling force on the outer magnet 80B on the same radial line. Similarly, the core 10 of winding B will also pull the opposite magnet 80A. This will cause the two magnets 80 on the radial line to pull each other. If the problem of the two sets of magnets 80 being pulled in opposite directions on the same radial line (winding A pulls magnet 80B, winding B pulls magnet 80A) is not solved, the centrifugal force simulation will be too far off.

[0041] For this question, see Figure 1 The first implementation method is as follows: the outer ring 3 of the winding core is an integral modular structure. Each module has a fixed gap preset in advance, corresponding to the centrifugal force requirement of a specific speed, ensuring that the distance and electromagnetic force are fixed, so that winding A corresponds to pulling magnet A 80 and winding B corresponds to pulling magnet B 80. The target speed can be adapted by directly replacing the corresponding module. The advantages are simple structure, convenient operation, low cost, and suitable for batch preprocessing of single fixed speed working conditions.

[0042] For the second implementation method, please refer to [link / reference]. Figure 5 The outer ring 3 of the winding core is composed of multiple independent arc plates 30. Each arc plate 30 is connected to a radial moving mechanism, which includes a servo drive 9. The servo drive 9 is connected to the arc plate 30 and drives the arc plate 30 to move radially back and forth. The spacing can be synchronously adjusted by the control system 5 according to the magnitude of the excitation current. Although this structure is more complex and slightly more expensive than the overall modular design, it can avoid mutual interference of the magnetic fields of the radially opposite winding cores 10 by adjusting the spacing, prevent uneven force caused by magnetic crosstalk, and flexibly adapt to various working conditions such as low speed, high speed, and deceleration.

[0043] In low-speed operation: the required centrifugal force is small, the corresponding excitation current is reduced, the electromagnetic force is weak, and the magnetic field radiation range is small. The control system 5 controls the radial movement mechanism to drive each arc plate 30 to move towards the rotor, so that the winding core 10 is slightly closer to the inner A magnet 80. At this time, the electromagnetic force only acts on the directly opposite A magnet 80, the magnetic field radiation range is small, and it will not extend to the B magnet 80 on the same radial direction, thus avoiding cross-pulling.

[0044] When switching to high-speed operation: the required centrifugal force is large, the excitation current is increased, the electromagnetic force is enhanced, and the magnetic field radiation range will expand accordingly. At this time, the control system 5 synchronously controls the radial movement mechanism, driving each arc plate 30 to move outward radially, increasing the distance between the winding core 10 and the inner A magnet 80. This can limit the enhanced magnetic field radiation range, prevent the magnetic field from extending to the B magnet 80 on the outer side of the same radial direction, and avoid the cross-entanglement problem of A winding pulling B magnet 80 and B winding pulling A magnet 80. This ensures that the electromagnetic force only acts precisely on the corresponding magnet 80, matching the centrifugal force requirements at high speed.

[0045] By adjusting the current and thus the spacing, the centrifugal force at different speeds can be matched to achieve centrifugal force simulation under all working conditions. This adapts to the stress release and position setting requirements of rotors at different speeds, making it more versatile and adaptable, and able to meet diverse test scenarios.

[0046] Furthermore, the circumferential magnetic shielding plate 6 and the upper and lower axial magnetic shielding plates 7 are both fixedly connected to the corresponding arc-shaped plates 30 and move radially synchronously with the arc-shaped plates 30. This ensures that the magnetic field is effectively isolated and cross-contamination is avoided during the movement of the arc-shaped plates 30, guaranteeing that the magnetic field acts directionally on the target magnet 80. At the same time, the distance between the arc-shaped plates 30 and the rotor needs to be limited, with a reasonable gap reserved. This gap must allow the electromagnetic heating coil to smoothly extend and carry out heating work. It should not be too close, preventing the heating coil from entering, nor too far, affecting the heating effect and electromagnetic force transmission. This ensures that heating, electromagnetic force action, and magnetic shielding do not interfere with each other and operate normally.

[0047] See Figure 1 The induction heating coil 20 is connected to the coil base 21, and the coil base 21 is connected to the lifting mechanism 22. The lifting mechanism 22 drives the coil base 21 to move vertically up and down, causing the electromagnetic heating coil to extend into or move out of the annular gap between the rotor assembly and the winding core 10.

[0048] Furthermore, a temperature detection probe is arranged inside the heating cylinder, and the induction heating coil 20 is connected to the parameterized temperature control system. Before the test, the rotor diameter and permanent magnet 80 specifications are input. The temperature control system matches the critical demagnetization temperature of the magnet 80 and sets the upper limit threshold for heating. The heating power and heating time are controlled in a closed loop to prevent the magnet 80 from losing magnetism at high temperature.

[0049] Example: Rotor outer diameter: 127.6 mm; Rotor stack height: 110.7 mm; The dimensions of the large magnet 80 are 20mm*18.45mm*4mm, with a center of gravity of 53.2mm. The dimensions of the small magnet 80 are: 10mm*18.45mm*2.8mm, with a center of gravity of 59.0mm. When the motor speed is 15,000 rpm, the centrifugal force on the large magnet 80 is approximately 1450 N; the centrifugal force on the small magnet 80 is approximately 560 N. The grade 80 large and small magnets are 48UH, and the long-term allowable operating temperature is 180℃. In the equipment of this application, the temperature of the rotor electric heating should be controlled below 180℃ and should not exceed the long-term allowable operating temperature of the magnet 80 to prevent the magnet 80 from demagnetizing; current should be passed through the electromagnetic winding 11 to generate a magnetic field of about 10T; after the rotor has been subjected to multiple electric heating and electromagnetic centrifugal force, the rotor stress can be released and the dynamic balance can be stabilized.

[0050] The method of using the electromagnetic centrifuge with motor rotor includes the following steps: S1. Pre-processing test: The rotor assembly is placed in the rotor dynamic balancing equipment for initial dynamic balancing test. The initial dynamic balance value of the rotor assembly is accurately measured and recorded as a reference for subsequent comparison. S2. Rotor positioning and installation: The rotor assembly that has completed the initial test is assembled on the rotor support plate 40 of the equipment. The rotor support plate 40 has a positioning hole in the center that matches the rotor assembly shaft 81. The rotor assembly shaft 81 is inserted into the positioning hole for precise positioning, so that each magnet 80 on the rotor assembly corresponds one-to-one with each winding core 10 of the equipment, ensuring the precise action of subsequent electromagnetic force. S3. Heating treatment: The lifting mechanism 22 drives the coil base 21 and the heating cylinder connected to it to descend vertically, so that the heating cylinder extends into the annular gap between the rotor assembly and the winding core 10; the induction heating coil 20 is started, and according to the pre-input rotor diameter and permanent magnet 80 specifications, the temperature control system automatically matches the critical demagnetization temperature of the magnet 80 and sets the upper limit threshold of heating, and controls the induction heating coil 20 to heat the rotor assembly according to the set temperature and heating time, thus completing the core stress pretreatment; S4. Electromagnetic centrifugal simulation: After heating is completed, the coil base 21 and heating cylinder are driven to rise vertically by the lifting mechanism 22, so that the heating cylinder moves out of the annular gap; the excitation system of the winding core 10 is started, the control system 5 adjusts the excitation current according to the preset centrifugal force parameters, and simultaneously controls the radial movement mechanism to adjust the distance between the winding core 10 and the magnet 80, applying a radially outward electromagnetic centrifugal force to the rotor assembly, maintaining the electromagnetic centrifugal force for a preset duration, simulating the centrifugal force condition when the rotor is running at high speed; S5. Secondary dynamic balancing test: After the electromagnetic centrifugal simulation is completed, the excitation system is turned off, the rotor assembly is removed, and it is placed in the rotor dynamic balancing equipment again for dynamic balancing test. The dynamic balancing values ​​are accurately measured and recorded. S6. Cyclic Detection: Repeat steps S3 to S5 to continuously heat, simulate electromagnetic centrifugation, and perform dynamic balance detection on the rotor assembly until the dynamic balance values ​​measured at least twice in a row tend to be stable without significant fluctuations. S7. Dynamic Balance Correction: Based on the stable dynamic balance values ​​in step S6, perform dynamic balance correction on the rotor assembly to ensure that the dynamic balance accuracy of the rotor assembly reaches the preset standard, thus completing the centrifugal stress release and dynamic balance pretreatment of the rotor.

[0051] For any parts not mentioned in this invention, existing technologies can be used or referenced.

[0052] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in the present invention, and these should all be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An electromagnetic centrifuge device for an electric motor rotor, characterized in that, It includes a centrifugal force simulation module for simulating the centrifugal force of a rotor rotating at high speed and a stress relief module for releasing the residual stress in the rotor core; The centrifugal force simulation module includes a winding core and an electromagnetic force winding wound around the winding core. The winding core is arranged around the rotor assembly and is correspondingly set with the magnets on the rotor assembly. By energizing the electromagnetic force winding, a radially outward electromagnetic force is applied to the magnets, causing the magnets to displace along the bonding interface. The stress relief module is equipped with an induction heating coil that can be adjusted up and down. The induction heating coil is arranged coaxially around the rotor assembly. It acts on the rotor assembly through induction heating to reduce the stress threshold of the rotor core material and promote the release of residual processing and assembly stress inside the rotor core.

2. The electromagnetic centrifuge with motor rotor according to claim 1, characterized in that, The outer end of the winding core is assembled to the outer ring of the winding core through a fixed structure. The outer ring of the winding core is installed on the upper end of the support base. The rotor support disk is coaxially arranged at the center of the support base. The rotor assembly is coaxially positioned and installed at the center of the rotor support disk.

3. The electromagnetic centrifuge with motor rotor according to claim 2, characterized in that, The outer ring of the winding core is made of non-magnetic material, and a circumferential magnetic shield is fixedly installed between adjacent winding cores. An axial magnetic shield is provided at both the upper and lower ends of the winding core. The winding core retains a magnetic working surface only on the side facing the rotor magnet.

4. The electromagnetic centrifuge with motor rotor according to claim 1, characterized in that, It also includes a control system and an adjustable output power supply, which is electrically connected to the centrifugal force simulation module. The control system changes the output current of the electromagnetic force winding to change the magnitude of the electromagnetic force.

5. The electromagnetic centrifuge for motor rotors according to claim 3, characterized in that, The outer ring of the winding core is composed of multiple sets of independent arc plates. Each arc plate is slidably assembled on the upper end of the support base and connected to the radial moving mechanism. The control system synchronously controls the radial moving mechanism to move and adjust the distance between the winding core and the rotor magnet according to the magnitude of the excitation current.

6. The electromagnetic centrifuge for motor rotors according to claim 5, characterized in that, The circumferential magnetic shielding plate and the upper and lower axial magnetic shielding plates are all fixedly connected to the corresponding arc-shaped plates and move radially synchronously with the arc-shaped plates.

7. The electromagnetic centrifugal device for motor rotors according to claim 5, characterized in that, The radial movement mechanism includes a servo drive component, which is connected to an arc-shaped plate. The servo drive component drives the arc-shaped plate to move radially back and forth.

8. The electromagnetic centrifuge for motor rotors according to claim 1, characterized in that, The induction heating coil is connected to a coil base, and the coil base is connected to a lifting mechanism; the lifting mechanism drives the coil base to move vertically up and down, causing the electromagnetic heating coil to extend into or move out of the annular gap between the rotor assembly and the winding core.

9. The electromagnetic centrifuge for motor rotors according to claim 8, characterized in that, A temperature detection probe is arranged inside the heating cylinder, and the induction heating coil is connected to a parameterized temperature control system. Before the test, the rotor diameter and permanent magnet specifications are input. The temperature control system matches the critical demagnetization temperature of the magnet and sets the upper limit threshold for heating. The heating power and heating time are controlled in a closed loop to prevent the magnet from losing its magnetism at high temperatures.

10. A method of using the electromagnetic centrifugal device with motor rotor according to any one of claims 1 to 9, characterized in that, Includes the following steps: S1. Pre-processing test: The rotor assembly is placed in the rotor dynamic balancing equipment for initial dynamic balancing test. The initial dynamic balance value of the rotor assembly is accurately measured and recorded as a reference for subsequent comparison. S2. Rotor positioning and installation: Assemble the rotor assembly, which has completed the initial test, in the center of the equipment, so that each magnet on the rotor assembly corresponds to each winding core of the equipment to ensure the subsequent electromagnetic force. S3. Heating treatment: The drive coil base and the heating cylinder connected to it are lowered vertically, so that the heating cylinder extends into the annular gap between the rotor assembly and the winding core; The induction heating coil is started. Based on the pre-input rotor diameter and permanent magnet specifications, the temperature control system automatically matches the critical demagnetization temperature of the magnet and sets the upper limit threshold for heating. The induction heating coil is then controlled to heat the rotor assembly according to the set temperature and heating time to complete the core stress pretreatment. S4. Electromagnetic centrifugal simulation: After heating is completed, the drive coil base and heating cylinder are raised vertically, so that the heating cylinder moves out of the annular gap; the excitation system of the winding core is started, and the excitation current is adjusted according to the preset centrifugal force parameters to apply radial outward electromagnetic centrifugal force to the rotor assembly, maintain the electromagnetic centrifugal force for a preset duration, and simulate the centrifugal force condition when the rotor is running at high speed. S5. Secondary dynamic balancing test: After the electromagnetic centrifugal simulation is completed, the excitation system is turned off, the rotor assembly is removed, and it is placed in the rotor dynamic balancing equipment again for dynamic balancing test. The dynamic balancing values ​​are accurately measured and recorded. S6. Cyclic Detection: Repeat steps S3 to S5 to continuously heat, simulate electromagnetic centrifugation, and perform dynamic balance detection on the rotor assembly until the continuously measured dynamic balance values ​​tend to stabilize without significant fluctuations. S7. Dynamic Balance Correction: Based on the stable dynamic balance values ​​in step S6, perform dynamic balance correction on the rotor assembly to ensure that the dynamic balance accuracy of the rotor assembly reaches the preset standard.

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