Motor stator and rotor assembly and air gap maintenance system and method for permanent magnet suspension hoist

Abstract

The application discloses a permanent magnet suspension type hoist motor stator-rotor assembly and air gap maintaining system and method, which comprises a base platform, a stator support and fine adjustment platform, a rotor hoisting and centering module, an air gap measuring device, a displacement detecting device and a central control module. The air gap measuring device collects multi-point air gap data in real time, and the central control module calculates the real-time eccentricity state of the rotor relative to the stator and generates a control instruction accordingly. In the assembly stage, the stator displacement driving device is driven to adjust the position of the stator, so that the static fine centering of the rotor in the stator cavity is realized; in the simulation load or running stage, the stator is driven to perform a following compensation movement, so that the rotor displacement caused by the load is dynamically offset, and the air gap is automatically kept uniform. The application solves the technical problems of safe assembly and air gap maintaining of the heavy-duty permanent magnet motor in the bearing-free running, and significantly improves the assembly precision, safety and running stability.

Description

Technical Field

[0001] This invention relates to the field of motor manufacturing and assembly technology, and in particular to a system and method for assembling the stator and rotor and maintaining the air gap of a permanent magnet suspended hoist motor. Background Technology

[0002] With the increasing demands for safety and efficiency in heavy-duty applications such as mining and metallurgy, low-speed, high-torque permanent magnet synchronous motors are widely used in permanent magnet suspended hoist systems. These motors typically employ large-diameter stator and rotor structures, resulting in significant overall weight, high magnetic field strength, and a design that eliminates the need for traditional bearing support. Their assembly precision and operational stability directly impact the safe and reliable operation of the entire machine.

[0003] In the manufacturing and assembly of such motors, a uniform and stable radial air gap must be maintained between the stator and rotor to ensure electromagnetic performance, reduce vibration and noise, and avoid the generation of abnormal electromagnetic forces. However, due to the large size and mass of the rotor, it is usually necessary to lift the rotor into the stator cavity during the assembly stage. Without rigid support, it is difficult to accurately control the rotor's attitude and spatial position, resulting in problems such as high alignment difficulty and high safety risks during the assembly process.

[0004] On the other hand, during actual operation, the load on the hoist exhibits significant variation. Under heavy load or fluctuating operating conditions, the rotor inevitably undergoes slight displacement or deformation, altering the originally designed ideal air gap state. Uneven air gap distribution not only affects motor efficiency but may also induce unbalanced electromagnetic forces, thereby exacerbating mechanical vibration and structural fatigue, and reducing the long-term reliability of the system.

[0005] In addition, in the existing assembly and debugging process, the control of the relative position of the stator and rotor and the air gap status mostly relies on offline detection or manual experience judgment. There is a lack of means to continuously sense and finely adjust the air gap status during the assembly stage and operation, making it difficult to simultaneously take into account the requirements of assembly safety, alignment accuracy and air gap stability during operation.

[0006] Therefore, for high-power permanent magnet suspension hoist motors, how to achieve high-precision alignment of the stator and rotor while ensuring safety during assembly and operation, and how to maintain the stability of the air gap state when operating conditions change, remains a key technical problem that urgently needs to be solved. Summary of the Invention

[0007] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a permanent magnet suspended hoist motor stator and rotor assembly and air gap maintenance system and method, which is used to solve the problem of high-precision and safe alignment during the assembly of heavy permanent magnet motors and realize the dynamic automatic maintenance of the air gap during operation.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a permanent magnet suspended hoist motor stator and rotor assembly and air gap maintenance system, comprising:

[0009] Basic platform;

[0010] A stator support and fine-tuning platform is set on the base platform to support and fix the motor stator. The stator support and fine-tuning platform integrates a stator displacement drive device that can drive the stator to make multi-degree-of-freedom precision adjustments in the horizontal plane.

[0011] The rotor hoisting and centering module is used for hoisting, attitude adjustment, and initial positioning of heavy rotors without bearing support.

[0012] The air gap measuring device includes multiple non-contact displacement sensors evenly arranged along the inner circumference of the stator, used to measure the radial air gap value at multiple positions between the stator and rotor in real time and synchronously.

[0013] A displacement detection device is used to monitor the position of the stator support and the fine-tuning platform in real time;

[0014] The central control module is connected to the air gap measuring device, the displacement detection device, and the stator displacement drive device via signals, respectively.

[0015] The central control module is configured to execute the following control procedures:

[0016] The system receives multi-point air gap data collected in real time by the air gap measuring device and calculates the real-time eccentricity state of the rotor relative to the stator based on the multi-point air gap data.

[0017] During the assembly stage, a first control command is generated based on the real-time eccentricity state to drive the stator displacement drive device to adjust the position of the stator support and the fine-tuning platform so that the rotor is statically aligned with the theoretical center of the stator cavity.

[0018] During the simulated load or operation monitoring phase, a second control command is generated based on the dynamic changes in the air gap data. This command drives the stator displacement drive device to control the stator support and fine-tuning platform to perform follow-up compensation movements, thereby offsetting the air gap unevenness caused by rotor displacement and achieving dynamic maintenance of the air gap.

[0019] Furthermore, the stator displacement drive device is a multi-degree-of-freedom micro-motion adjustment mechanism, including a high-precision servo electric cylinder or linear motor arranged in a first direction and a second direction that are perpendicular to each other in the horizontal plane. The drive unit in each direction integrates a force sensor and a position encoder.

[0020] Furthermore, the multiple non-contact displacement sensors in the air gap measuring device are arranged symmetrically and uniformly at N points along the inner circumference of the stator, where N is an even number greater than or equal to 4.

[0021] Each sensor is used to synchronously measure the actual air gap value at its installation location and transmit the actual air gap value to the central control module.

[0022] Furthermore, the central control module is further configured as follows:

[0023] Obtain the target air gap value for the motor;

[0024] Calculate the air gap deviation value at each measurement point based on the actual air gap value and the target air gap value at each measurement point;

[0025] Based on the air gap deviation values ​​measured by at least one set of symmetrically arranged sensors, the real-time eccentricity vector of the rotor center relative to the stator center in the horizontal plane is calculated. The real-time eccentricity vector includes a first eccentricity component in a first direction and a second eccentricity component in a second direction.

[0026] The first control command and the second control command are both generated based on the first eccentric component and the second eccentric component, and are used to control the stator displacement drive device to drive the stator support and fine-tuning platform to move in the direction that cancels the real-time eccentric vector.

[0027] Furthermore, the central control module is further configured to generate displacement commands using a control algorithm that includes proportional and / or derivative elements;

[0028] The formula for calculating the command displacement of the stator support and fine-tuning platform in the first direction is configured as follows:

[0029] ;

[0030] The formula for calculating the command displacement of the stator support and fine-tuning platform in the second direction is configured as follows:

[0031] ;

[0032] in, , These are the command displacement amounts in the first direction and the command displacement amounts in the second direction, respectively. , These are the first eccentric component and the second eccentric component, respectively. , These are the proportional gains in the first and second directions, respectively. , These are the differential gains in the first and second directions, respectively. , These are the rates of change of the eccentric components in the first and second directions, respectively;

[0033] Furthermore, the control algorithm integrates dead zone judgment logic: when the absolute value of any eccentric component is less than a first preset threshold, the eccentric component is set to zero.

[0034] Furthermore, the rotor hoisting and centering module includes a gantry crane, an anti-torsion lifting device, a multi-dimensional attitude adjustment mechanism, and a magnetic balance auxiliary device;

[0035] The magnetic balancing auxiliary device is a movable high-permeability shielding plate or a controllable reverse electromagnetic coil group set between the stator and the rotor, used to partially cancel or shield the strong magnetic attraction between the two during the process of the rotor being hoisted close to the stator.

[0036] Furthermore, the displacement detection device includes a high-precision grating ruler or laser tracker installed between the stator support and fine-tuning platform and the base platform, for providing full closed-loop feedback of the macroscopic displacement of the stator support and fine-tuning platform.

[0037] Furthermore, the stator support and fine-tuning platform is also equipped with a strong magnetic shock protection locking mechanism. During the non-adjustment phase, the strong magnetic shock protection locking mechanism mechanically locks the stator support and fine-tuning platform to the base platform to prevent the stator from moving unexpectedly due to the sudden attraction force generated by the rotor's strong magnetic field.

[0038] A method for assembling the stator and rotor of a permanent magnet suspended hoist motor and maintaining the air gap, applied to the system described above, includes:

[0039] Step S1: Fix the stator to the stator support and fine-tuning platform, and activate the anti-strong magnetic impact locking mechanism to lock the platform position;

[0040] Step S2: Operate the rotor hoisting and centering module to smoothly hoist the rotor to the initial position in the stator cavity. During this process, the magnetic balancing auxiliary device is activated to reduce the influence of strong magnetic attraction.

[0041] Step S3: Release the locking state of the anti-strong magnetic impact locking mechanism and start the air gap measuring device and displacement detection device; the central control module reads the initial air gap data. If the magnitude of the calculated initial eccentric vector is greater than the second preset threshold, the first control command is generated and executed to drive the stator displacement driving device to adjust the stator position until the magnitude of the eccentric vector is less than or equal to the second preset threshold, thus completing the static alignment of the rotor in the stator cavity.

[0042] Step S4: Under simulated rotor loading or actual operating conditions, the central control module continuously monitors the air gap data. When it detects that the air gap changes due to simulated load or operating conditions and the recalculated real-time eccentricity vector exceeds the third preset threshold, it automatically generates and executes the second control command to drive the stator displacement drive device to control the stator support and fine-tuning platform to perform follow-up compensation adjustment, so that the air gap value is restored and kept uniform.

[0043] Furthermore, in step S4, the simulated load is achieved by applying a controllable radial force or torque to the rotor shaft end; the third preset threshold is less than or equal to the second preset threshold.

[0044] The beneficial effects of this invention are:

[0045] 1. Improve the safety and efficiency of heavy permanent magnet motor assembly: This invention constructs an assembly system for coordinated adjustment of stator and rotor, making the hoisting, centering and positioning of heavy strong magnet rotors under bearing-free conditions controllable and adjustable. This effectively reduces the safety risks caused by magnetic attraction and attitude instability during assembly, achieving high safety, high precision and high efficiency in stator and rotor assembly, and significantly improving the reliability and repeatability of traditional assembly operations.

[0046] 2. Achieve dynamic stability of the air gap state between the stator and rotor: This invention is not only applicable to the alignment adjustment during the assembly stage, but also to the responsive adjustment of the air gap changes between the stator and rotor under simulated load or operation monitoring conditions, so that the air gap distribution is maintained within the ideal range under different operating conditions, thereby reducing the air gap unevenness and additional electromagnetic force caused by rotor displacement, and improving the smoothness, reliability and service life of the motor operation.

[0047] 3. Improve the intelligence and consistency of assembly and debugging processes: By systematically integrating detection, adjustment and control functions, this invention reduces the reliance on manual experience and repeated manual calibration, making the stator and rotor position control and air gap adjustment processes more precise, stable and consistent. This is conducive to the standardized assembly and high-quality manufacturing of high-power permanent magnet motors, meeting the requirements for precision and mass production in engineering applications. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of the assembly and air gap retention system of the permanent magnet suspended hoist motor stator and rotor in this invention;

[0049] Figure 2 This is a flowchart of the steps in the method for assembling the stator and rotor of the permanent magnet suspended hoist motor and maintaining the air gap in this invention.

[0050] Reference numerals: 1. Air gap measuring device; 2. Displacement detection device; 3. Central control module; 4. Stator displacement drive device. Detailed Implementation

[0051] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Identical components are denoted by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "upper," and "lower" used in the following description refer to directions in the accompanying drawings, and the terms "bottom surface," "top surface," "inner," and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0052] Example 1, refer to Figure 1 This is the first embodiment of the present invention. This embodiment provides a permanent magnet suspended hoist motor stator and rotor assembly and air gap retention system. This embodiment provides a permanent magnet suspended hoist motor stator and rotor assembly and air gap retention system, which is suitable for high-power, low-speed, large-diameter permanent magnet synchronous motors, and is especially suitable for heavy rotor assembly and operation air gap control scenarios under bearing-free support conditions.

[0053] I. Overall System Structure;

[0054] The entire system is installed on a reinforced equipment foundation, including a foundation platform, a stator support and fine-tuning platform, a rotor hoisting and centering module, an air gap measuring device 1, a displacement detection device 2, and a central control module 3.

[0055] The foundation platform is a reinforced concrete or monolithic cast steel structure, used to provide a stable installation reference and load-bearing capacity for the entire system.

[0056] The stator support and fine-tuning platform is set on the base platform to support and fix the motor stator. Taking this embodiment as an example, the motor stator weighs approximately 18 tons and is rigidly fixed to the stator support and fine-tuning platform by a special stator clamp to ensure that the stator remains relatively fixed to the platform during the adjustment process.

[0057] The stator support and fine-tuning platform integrates a stator displacement drive device 4, used to drive the stator support and fine-tuning platform to perform multi-degree-of-freedom precision adjustments in the horizontal plane. Specifically, the stator displacement drive device 4 consists of four sets of high-precision servo electric cylinders, arranged in a cross shape, corresponding to the X and Y degrees of freedom respectively. Each servo electric cylinder integrates a force sensor and a position encoder to achieve closed-loop control of displacement and force. Through closed-loop control, the stator position can automatically follow and adjust according to the slight displacement of the rotor caused by the load, thereby maintaining a uniform air gap during motor operation.

[0058] A displacement detection device 2 is installed between the stator support and the fine-tuning platform and the foundation platform. In this embodiment, a grating ruler is used as the displacement detection device 2 to detect the actual displacement state of the stator support and the fine-tuning platform relative to the foundation platform in real time, and to feed the displacement data back to the central control module 3.

[0059] The rotor hoisting and alignment module is used for hoisting, attitude adjustment, and initial positioning of heavy rotors without bearing support. In this embodiment, the rotor weighs approximately 12 tons. The rotor hoisting and alignment module adopts a double-beam gantry crane structure, and the lifting device integrates a hydraulic attitude adjustment mechanism for adjusting the rotor's pitch and yaw angles. Simultaneously, the lifting device is also equipped with a retractable silicon steel sheet shielding plate assembly to weaken the magnetic attraction between the stator and rotor during the rotor's entry into the stator cavity, thereby reducing assembly risks.

[0060] The air gap measuring device 1 includes multiple non-contact displacement sensors evenly arranged along the inner circumference of the stator. In this embodiment, an eddy current displacement sensor is set every 90 degrees on the inner circumferential surface of the stator, and the probes of the four eddy current displacement sensors all point to the outer circumferential surface of the rotor, for synchronously measuring the radial air gap value of the stator and rotor at different orientations.

[0061] The central control module 3 is connected to the air gap measuring device 1, the displacement detection device 2, and the stator displacement drive device 4 via signals. In this embodiment, the central control module 3 is composed of a programmable logic controller (PLC) and an industrial control computer, and is used to complete data acquisition, eccentricity calculation, control command generation, and execution control.

[0062] II. Working principle of Example 1;

[0063] The working process of this embodiment includes static alignment control during the assembly stage and dynamic air gap maintenance control during the simulated load or operation monitoring stage.

[0064] (a) The working principle of the assembly stage;

[0065] In the initial stage of assembly, the stator is first fixed to the stator support and fine-tuning platform using a special fixture, and the stator support and fine-tuning platform are locked to keep them stationary relative to the base platform.

[0066] Subsequently, the rotor is hoisted to the stator inlet position using the rotor hoisting and alignment module. As the rotor slowly enters the stator cavity, silicon steel sheet shielding plates are gradually extended to shield the magnetic field between the stator and rotor, thereby weakening most of the magnetic attraction and preventing the rotor from being attracted to the stator inner wall by strong magnetic force and colliding if it is not aligned.

[0067] After the rotor is initially positioned, the locking state of the stator support and fine-tuning platform is released. At this time, the central control module 3 receives multi-point air gap data from the air gap measuring device 1. Since the four eddy current displacement sensors are evenly distributed on the inner circumference of the stator, the central control module 3 can calculate the real-time eccentricity of the rotor relative to the stator based on the air gap values ​​at each measuring point, including the magnitude and direction of the eccentricity.

[0068] In this embodiment, the theoretical air gap value is designed to be 3.0 mm, with an allowable deviation range of ±0.03 mm. When the central control module 3 determines that the current air gap distribution does not meet the above design requirements, it generates a first control command and drives the stator displacement drive device 4 to operate. Specifically, the central control module 3 controls the servo electric cylinder in the corresponding direction to extend or retract according to the eccentricity direction and the magnitude of the eccentricity, so that the stator support and the fine-tuning platform produce a slight displacement in the horizontal plane, thereby driving the stator to move as a whole.

[0069] During the adjustment of the servo electric cylinder, the displacement detection device 2 monitors the actual displacement of the stator support and the fine-tuning platform in real time and feeds the displacement data back to the central control module 3 to form a displacement closed-loop control. Through multiple iterative adjustments, the air gap values ​​at the four measuring points tend to be consistent and stabilize within the range of 3.0mm ± 0.03mm, thereby achieving static alignment of the rotor relative to the stator during the assembly stage.

[0070] (ii) Working principle of the simulated load or operation monitoring phase;

[0071] After static alignment during the assembly phase is completed, the simulated load or operational monitoring phase can begin. In this embodiment, a radial load is applied to the rotor shaft end via a hydraulic loading device to simulate the rotor stress state caused by load changes during actual operation of the hoist.

[0072] When a radial load is applied to the rotor, the rotor may experience a slight sinking or shift, causing a change in the air gap distribution between the stator and rotor. For example, when the rotor shifts downwards under load, the air gap value at the lower measuring point decreases, while the air gap value at the upper measuring point increases.

[0073] At this time, the air gap measuring device 1 feeds back the air gap changes at each measuring point to the central control module 3 in real time. The central control module 3 recalculates the rotor's eccentricity state based on the dynamic changes in the air gap data and generates a second control command. Unlike the assembly stage, the second control command is used to drive the stator displacement drive device 4 to perform a following compensation motion.

[0074] Specifically, the central control module 3 controls the stator support and fine-tuning platform to move slightly in the direction corresponding to the rotor offset direction. For example, when the rotor offsets downward, it drives the stator support and fine-tuning platform to move downward by a corresponding compensation amount, so that the air gap in the vertical direction becomes consistent again, thereby offsetting the influence of rotor displacement on the uniformity of the air gap.

[0075] Through the above control methods, the stator can make follow-up adjustments to the rotor displacement during the simulated load or operation monitoring stage, realize the dynamic maintenance of the air gap, and avoid unilateral magnetic pull and additional vibration caused by uneven air gap.

[0076] III. Technical effects of Example 1;

[0077] Based on the above structure and working principle, this embodiment has at least the following technical effects:

[0078] 1. Under bearingless support conditions, safe and controllable assembly of heavy-duty strong magnetic rotors was achieved, significantly reducing the risk of magnetic collisions during the assembly process;

[0079] 2. By combining multi-point air gap detection with stator position adjustment, high-precision static alignment was achieved during the assembly stage;

[0080] 3. Under simulated load or operation monitoring conditions, the stator can follow the rotor displacement to compensate for the displacement, effectively maintain the uniformity of the air gap between the stator and rotor, and improve the stability and reliability of motor operation.

[0081] 4. Reduces reliance on manual experience, improves the consistency and repeatability of assembly and debugging processes, and is suitable for engineering applications of high-power permanent magnet hoist motors.

[0082] Example 2 is the second embodiment of the present invention. Based on Example 1, this embodiment further provides a more complete intelligent assembly and air gap maintenance system for the stator and rotor of a permanent magnet suspended hoist motor, which is suitable for high-precision assembly and dynamic air gap control scenarios of 30-ton stators and heavy permanent magnet rotors.

[0083] I. System Structure Composition;

[0084] The system structure in this embodiment is basically the same as that in the other embodiment.

[0085] In this embodiment, the stator displacement drive device 4 includes drive units arranged in a horizontal plane along a first direction and a second direction that are perpendicular to each other. Each drive unit can be implemented using a high-precision servo electric cylinder or a linear motor. Each drive unit integrates a force sensor and a position encoder to achieve real-time detection and closed-loop control of the output force and displacement, thereby ensuring that sub-millimeter level or even higher precision position adjustment can still be achieved when driving a large inertia stator platform.

[0086] The air gap measuring device 1 consists of multiple non-contact displacement sensors symmetrically and uniformly arranged at N points along the inner circumference of the stator, where N is an even number greater than or equal to 4, such as a 4-point or 8-point arrangement. Each non-contact displacement sensor is used to synchronously measure the actual air gap value Gi between the stator and rotor at its installation position and transmit the actual air gap value to the central control module 3 in real time.

[0087] The central control module 3 is the core control unit of the system, which is usually composed of a programmable logic controller and an industrial control computer. It is used to collect data from the air gap measuring device 1 and the displacement detection device 2, and generate control commands based on the built-in control algorithm to drive the stator displacement drive device 4 to complete the adjustment and compensation of the stator position.

[0088] II. Working principle of Example 2;

[0089] (I) Principles of air gap data acquisition and eccentric vector calculation;

[0090] During system operation, N non-contact displacement sensors in the air gap measuring device 1 are uniformly arranged along the inner circumference of the stator. Assume the angle corresponding to the installation position of the i-th sensor is... i, the air gap value measured in real time is denoted as Gi, and the unit is millimeters.

[0091] The central control module 3 pre-stores the target air gap value Gtarget for the motor. In this embodiment, the target air gap value Gtarget is set to 3.0 mm. The central control module 3 first calculates the target air gap value Gtarget according to the formula:

[0092] =Gi-Gtarget;

[0093] Calculate the air gap deviation value at each measurement point. .in:

[0094] >0 indicates that the air gap at this measuring point is too large;

[0095] <0 indicates that the air gap at the measuring point is too small.

[0096] When a 4-point symmetrical arrangement is adopted (e.g., 0°, 90°, 180°, 270°), the central control module 3 fits the discrete air gap deviation into an eccentric vector representing the rotor's offset state relative to the stator based on the air gap deviation values ​​of one or more sets of symmetrical sensors.

[0097] Under this simplified model, the eccentricity components of the rotor center relative to the stator center in the first direction (X direction) and the second direction (Y direction) are calculated as follows:

[0098] ;

[0099] in:

[0100] This represents the eccentric component of the rotor in the first direction;

[0101] This represents the eccentric component of the rotor in the second direction.

[0102] This eccentric vector can intuitively reflect the real-time offset and direction of the rotor relative to the stator center, providing a clear physical basis for subsequent control.

[0103] (II) Stator displacement command generation and control algorithm principle;

[0104] The central control module 3 is based on the calculated first eccentricity component. Second eccentric component The system generates a first control command and a second control command, which are used to drive the stator displacement drive device to control the stator support and fine-tuning platform to move in the direction of canceling the real-time eccentricity vector.

[0105] In this embodiment, the central control module 3 uses a control algorithm that includes proportional and / or differential elements to generate displacement commands. Specifically, the commanded displacement of the stator support and fine-tuning platform in the first direction is... Calculate using the following formula:

[0106] ;

[0107] Command displacement in the second direction Calculate using the following formula:

[0108] ;

[0109] in: , These are the proportional gains in the first and second directions, respectively. , These are the differential gains in the first and second directions, respectively. , These are the rates of change of the eccentric components in the first and second directions, respectively.

[0110] The negative sign in the above control formula indicates reverse compensation, that is, when the rotor is detected to deviate in a certain direction, the stator is driven to move in the corresponding direction to reduce or eliminate the eccentricity.

[0111] Furthermore, the central control module 3 integrates dead-zone detection logic. When any eccentric component... or When the absolute value of the eccentricity component is less than a first preset threshold, the eccentricity component is set to zero. In this embodiment, the first preset threshold is set to, for example, 0.01 mm. By setting a dead zone, frequent micro-movements of the actuator under extremely small eccentricity conditions can be avoided, thereby reducing mechanical wear and improving system stability.

[0112] Meanwhile, the central control module 3 also sets amplitude limits for displacement commands, such as limiting the maximum displacement within a single control cycle to 0.1mm, to prevent excessive instantaneous displacement of the stator due to measurement noise or abnormal data.

[0113] (III) A unified working mechanism for the assembly phase and the dynamic following phase;

[0114] During the assembly stage, the central control module 3, based on the aforementioned eccentric vector calculation and control algorithm, drives the stator support and fine-tuning platform to move gradually, aligning the rotor with the theoretical center position of the stator under static conditions. When the air gap values ​​at each measuring point are stable within Gtarget (e.g., 3.0 mm) and its allowable deviation range, the static alignment during the assembly stage is completed.

[0115] During the simulated load or actual operation monitoring phase, when the rotor flexes or displaces due to changes in external load, the air gap measuring device 1 will detect the dynamic changes in the air gap at each measuring point in real time. The central control module 3 does not distinguish the specific cause of the eccentricity, but continuously recalculates the eccentricity vector based on the air gap data and outputs new displacement commands in real time to drive the stator support and fine-tuning platform to perform reverse following compensation.

[0116] In this way, the stator can continuously follow the load displacement of the rotor, thereby maintaining the dynamic uniformity of the air gap between the stator and rotor throughout the entire operation.

[0117] III. Technical Effects of Embodiment 2;

[0118] Through the above structure and working principle, this embodiment achieves at least the following technical effects:

[0119] 1. Through multi-point air gap measurement and eccentric vector modeling, high-precision sensing of the rotor's offset state relative to the stator was achieved;

[0120] 2. Through a multi-degree-of-freedom stator displacement drive device, the large inertia stator can achieve high-precision and controllable micro-compensation in the horizontal plane;

[0121] 3. By introducing proportional and / or derivative control, dead zone and limiting mechanisms, the system response speed is improved while ensuring control stability;

[0122] 4. It can effectively suppress uneven air gap phenomenon during both the assembly stage and the load operation stage, and realize the static alignment and dynamic maintenance of the air gap between the stator and rotor.

[0123] 5. Improved the assembly safety, operational reliability, and service life of high-power permanent magnet suspended hoist motors.

[0124] Example 3 is the third embodiment of the present invention. This embodiment further provides a permanent magnet suspended hoist motor stator and rotor assembly and air gap maintenance system with magnetic balance and anti-impact safety assurance capabilities during the rotor hoisting and assembly stage. It is particularly suitable for high-risk assembly conditions of strong permanent magnet and large-mass rotors.

[0125] I. Further improvements to the system structure;

[0126] The system in this embodiment also includes a base platform, a stator support and fine-tuning platform, a stator displacement drive device 4, a rotor hoisting and centering module, an air gap measuring device 1, a displacement detection device 2, and a central control module 3.

[0127] (a) Rotor hoisting and alignment module;

[0128] The rotor hoisting and centering module includes a gantry crane, anti-torsion lifting device, multi-dimensional attitude adjustment mechanism, and magnetic balance auxiliary device.

[0129] Gantry cranes are used to provide the overall lifting and moving capability of rotors. Anti-torsion spreaders are installed between the rotor and the lifting system to prevent the rotor from rotating uncontrollably around its axis during the lifting process, which would affect the alignment accuracy and assembly safety.

[0130] A multi-dimensional attitude adjustment mechanism is set between the anti-torsion hanger and the rotor, which can adjust the pitch angle, yaw angle and lateral position of the rotor to achieve preliminary alignment of the rotor before entering the stator cavity.

[0131] A magnetic balancing auxiliary device is installed between the stator and the rotor, playing a crucial role during the rotor's hoisting and approach to the stator. This magnetic balancing auxiliary device can take the form of a movable high-permeability shielding plate or a controllable reverse electromagnetic coil assembly.

[0132] When a high-permeability shielding plate is used, it is inserted between the stator and rotor as the rotor gradually approaches the stator cavity. This guides and diverts part of the magnetic flux, thereby reducing the peak magnetic attraction force directly acting on the rotor. When a controllable reverse electromagnetic coil group is used, an excitation current opposite to the magnetic field of the permanent magnet is supplied to the coil, creating a reverse magnetic field in a local area to counteract part of the magnetic attraction force.

[0133] In this way, the magnetic balancing auxiliary device can partially cancel or shield the strong magnetic attraction between the stator and rotor without completely eliminating the magnetic force, so that the rotor is always in a controllable state when approaching the stator, avoiding violent collisions caused by sudden magnetic attraction.

[0134] (ii) Full closed-loop configuration of displacement detection device 2;

[0135] The displacement detection device 2 includes a high-precision grating ruler or laser tracker installed between the stator support and the fine-tuning platform and the foundation platform.

[0136] The displacement detection device 2 is used to measure the macroscopic displacement of the stator support and the fine-tuning platform in real time, and feeds the measurement results back to the central control module 3. Through this closed-loop feedback, the central control module 3 can verify the actual execution effect of the stator displacement drive device 4 in real time, avoiding the problem of inconsistent command displacement and actual displacement caused by elastic deformation of the mechanism, friction or external disturbance.

[0137] (iii) Anti-magnetic impact locking mechanism;

[0138] The stator support and fine-tuning platform is also equipped with a strong magnetic shock protection locking mechanism. This mechanism mechanically locks the stator support and fine-tuning platform to the foundation platform during non-adjustment phases.

[0139] Specifically, before the rotor has completed its initial positioning or before the central control module 3 issues an adjustment command, the anti-magnetic shock locking mechanism is in a locked state, preventing the stator support and fine-tuning platform from shifting relative to the base platform. This locking state prevents the stator from moving unexpectedly due to sudden magnetic attraction or external interference in a strong permanent magnetic field environment, thus avoiding assembly risks.

[0140] When entering the stator fine-tuning stage or the dynamic air gap holding stage, the central control module 3 controls the anti-strong magnetic shock locking mechanism to unlock, so that the stator support and fine-tuning platform can move in a controlled micro-movement under the action of the stator displacement drive device 4.

[0141] II. Working principle of Example 3;

[0142] (I) Principles of safe hoisting and initial alignment of rotor;

[0143] At the beginning of assembly, the anti-magnetic shock locking mechanism is locked, and the stator support and fine-tuning platform are mechanically locked to the foundation platform. The rotor is lifted by a gantry crane and anti-torsion lifting device, and its attitude is corrected by a multi-dimensional attitude adjustment mechanism.

[0144] As the rotor gradually approaches the stator cavity entrance, the magnetic balancing auxiliary device is activated simultaneously. By inserting a high-permeability shielding plate or activating the reverse electromagnetic coil group, the effective magnetic attraction between the stator and rotor is significantly weakened, allowing the rotor to enter the stator cavity in a low-impact and controllable manner.

[0145] During this stage, the stator remains fixed to prevent it from moving unexpectedly under the influence of a strong magnetic field, thus ensuring assembly safety.

[0146] (II) Fine-tuning stage and air gap alignment principle;

[0147] After the rotor has completed its initial positioning, the central control module 3 releases the locking state of the anti-strong magnetic shock locking mechanism. At this time, the air gap measuring device 1 begins to synchronously collect the air gap value Gi at multiple measuring points along the inner circumference of the stator.

[0148] The central control module 3 acquires the design target air gap value Gtarget, for example, set to 3.0 mm, and calculates the air gap deviation at each measuring point. =Gi-Gtarget. Based on at least one set of symmetrically arranged sensors, the central control module 3 calculates the real-time eccentricity vector of the rotor center relative to the stator center, including the first eccentricity component. Second eccentric component .

[0149] Subsequently, the central control module 3 generates control commands based on the eccentric component, and drives the stator displacement drive device 4 to control the stator support and fine-tuning platform to move in the direction of canceling the real-time eccentric vector, thereby achieving static alignment of the rotor relative to the stator.

[0150] During the adjustment process, the displacement detection device 2 provides full closed-loop feedback on the actual displacement of the stator platform, ensuring that the stator movement is consistent with the control command.

[0151] (III) The collaborative working principle of the dynamic maintenance phase;

[0152] During the simulated load or operation monitoring phase, when the rotor experiences a slight displacement due to changes in external load, the air gap measuring device 1 will detect the change in air gap distribution in real time. The central control module 3 continuously updates the eccentricity vector based on the real-time air gap data and drives the stator support and fine-tuning platform to perform reverse follow-up adjustments.

[0153] During this process, the anti-magnetic shock locking mechanism remains unlocked, but is always in a standby state that can respond quickly. When an abnormal impact is detected or the system enters a non-adjustment state, it can quickly relock the stator support and fine-tuning platform to improve the overall system's safety redundancy.

[0154] III. Technical Effects of Embodiment 3;

[0155] Through the above structure and working principle, this embodiment achieves at least the following technical effects:

[0156] 1. By introducing a magnetic balancing auxiliary device in the rotor hoisting and alignment module, the risk of sudden magnetic attraction of the strong permanent magnet rotor during the approach to the stator is effectively reduced, and the safety and controllability of the assembly process are improved.

[0157] 2. The anti-strong magnetic shock locking mechanism mechanically locks the stator support and fine-tuning platform during the non-adjustment stage to prevent the stator from moving unexpectedly due to strong magnetic fields or external disturbances.

[0158] 3. The accuracy and reliability of stator displacement control are improved through the closed-loop feedback of displacement detection device 2;

[0159] 4. Through the synergy of the above multiple safety and control mechanisms, the system possesses technical advantages of high security, high stability, and high consistency in both the assembly and operation monitoring stages.

[0160] Example 4 is the fourth embodiment of the present invention. This embodiment provides a method for assembling the stator and rotor of a permanent magnet suspended hoist motor and maintaining the air gap. This method is applied to the permanent magnet suspended hoist motor stator and rotor assembly and air gap maintenance system described in Examples 1 to 3 above. It is particularly suitable for the assembly and operation air gap control of high-power, strong permanent magnet, bearingless support structure motors.

[0161] I. Overall Methodological Approach;

[0162] The method in this embodiment takes safe assembly, precise alignment, and dynamic holding as its core process. Through strong magnetic shock protection locking, magnetic balance assistance, multi-point air gap measurement, and eccentric vector closed-loop control, it achieves high-precision static alignment of the stator and rotor during the assembly stage, as well as dynamic air gap holding during simulated load or actual operation.

[0163] II. Methods, Steps, and Working Principles;

[0164] Reference Figure 2 The method in this embodiment includes:

[0165] Step S1: Stator fixation and platform locking;

[0166] First, the motor stator is fixed to the stator support and fine-tuning platform, forming a rigid connection between the stator and the stator support and fine-tuning platform. Then, the anti-strong magnetic impact locking mechanism is activated to mechanically lock the stator support and fine-tuning platform to the base platform.

[0167] In this step, the anti-magnetic shock locking mechanism is used to prevent the stator from undergoing unexpected displacement due to the sudden magnetic attraction force generated by the strong permanent magnetic field during the subsequent rotor approaching the stator, thereby providing a safety guarantee for the subsequent assembly process.

[0168] Step S2: Initial positioning of the rotor with the assistance of hoisting and magnetic balancing;

[0169] The rotor hoisting and centering module is operated to smoothly lift the rotor to its initial position in the stator cavity using a gantry crane, anti-torsion lifting device, and multi-dimensional attitude adjustment mechanism.

[0170] As the rotor gradually approaches the stator, a magnetic balancing auxiliary device is activated. This device partially cancels or shields the strong magnetic attraction between the rotor and stator using a movable high-permeability shielding plate or a controllable reverse electromagnetic coil assembly, allowing the rotor to enter the stator cavity under controlled conditions and preventing attraction collisions.

[0171] During this stage, the stator support and fine-tuning platform remain locked to ensure the stator position is stable.

[0172] Step S3: Static alignment and execution of the first control command;

[0173] After the rotor has completed its initial positioning, the anti-strong magnetic shock locking mechanism is released, allowing the stator support and fine-tuning platform to enter an adjustable state. At the same time, the air gap measuring device 1 and the displacement detection device 2 are activated.

[0174] The central control module 3 reads initial air gap data collected from multiple measuring points along the inner circumference of the stator, and calculates the initial eccentricity vector of the rotor center relative to the stator center based on the difference between the actual air gap value and the design target air gap value at each measuring point. The magnitude of the eccentricity vector is used to characterize the degree of rotor eccentricity.

[0175] In this embodiment, a second preset threshold is set to determine whether static alignment adjustment needs to be performed. The second preset threshold is, for example, set to 0.05 mm. When the magnitude of the calculated initial eccentricity vector is greater than the second preset threshold, the central control module 3 generates a first control command.

[0176] The first control command, based on the direction and magnitude of the eccentric vector, drives the stator displacement drive device 4 to control the stator support and fine-tuning platform to move in the direction that counteracts the eccentric vector. By repeatedly executing the first control command, the magnitude of the eccentric vector is gradually reduced until it is less than or equal to a second preset threshold, thereby completing the static alignment of the rotor within the stator cavity.

[0177] Step S4: Dynamic air gap following and maintenance;

[0178] After static alignment is completed, the system enters the dynamic air gap following and holding stage. During this stage, control can be achieved by simulating rotor loading or by operating under actual conditions.

[0179] In this embodiment, the simulated load is achieved by applying a controllable radial force or torque to the rotor shaft end to simulate the rotor stress state caused by load changes during the actual operation of the hoist.

[0180] During this stage, the central control module 3 continuously monitors the multi-point air gap data collected by the air gap measuring device 1 and updates the eccentric vector in real time. When it is detected that the air gap distribution has changed due to changes in simulated load or operating conditions, and the recalculated real-time eccentric vector exceeds the third preset threshold, the central control module 3 automatically generates and executes the second control command.

[0181] The second control command is used to drive the stator displacement drive device 4 to control the stator support and fine-tuning platform to perform follow-up compensation adjustment, so that the stator moves slightly in the opposite direction relative to the rotor, thereby offsetting the influence of rotor displacement on air gap uniformity.

[0182] In this embodiment, the third preset threshold is less than or equal to the second preset threshold; for example, the third preset threshold can be set to 0.02 mm. By setting the third preset threshold to a smaller value, the system becomes more sensitive to changes in the air gap during operation, thereby achieving real-time maintenance of the air gap.

[0183] Through the above continuous closed-loop control, the air gap value of each measuring point is restored and stabilized near the design target air gap value, thereby achieving dynamic uniformity of the air gap.

[0184] III. Technical Effects of Embodiment Four;

[0185] Through the above methods and working principles, this embodiment achieves at least the following technical effects:

[0186] 1. By using a strong magnetic shock-proof locking mechanism and a magnetic balance auxiliary device in the early stage of assembly, the safety and controllability of the strong permanent magnet rotor assembly process are improved.

[0187] 2. By introducing a static alignment criterion with a second preset threshold, high-precision automatic alignment during the stator and rotor assembly stage is achieved;

[0188] 3. By introducing a third preset threshold that is less than or equal to the second preset threshold, the system can have higher sensitivity during operation, enabling dynamic tracking and stable maintenance of the air gap;

[0189] 4. By unifying the assembly and operation phases into the same control logic framework, the overall reliability, consistency, and engineering applicability of the system are improved.

[0190] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A permanent magnet suspended hoist motor stator and rotor assembly and air gap retention system, characterized in that, include: Basic platform; A stator support and fine-tuning platform is set on the base platform to support and fix the motor stator. The stator support and fine-tuning platform integrates a stator displacement drive device that can drive the stator to make multi-degree-of-freedom precision adjustments in the horizontal plane. The rotor hoisting and centering module is used for hoisting, attitude adjustment, and initial positioning of heavy rotors without bearing support. The air gap measuring device includes multiple non-contact displacement sensors evenly arranged along the inner circumference of the stator, used to measure the radial air gap value at multiple positions between the stator and rotor in real time and synchronously. A displacement detection device is used to monitor the position of the stator support and the fine-tuning platform in real time; The central control module is connected to the air gap measuring device, the displacement detection device, and the stator displacement drive device via signals, respectively. The central control module is configured to execute the following control procedures: The system receives multi-point air gap data collected in real time by the air gap measuring device and calculates the real-time eccentricity state of the rotor relative to the stator based on the multi-point air gap data. During the assembly stage, a first control command is generated based on the real-time eccentricity state to drive the stator displacement drive device to adjust the position of the stator support and the fine-tuning platform so that the rotor is statically aligned with the theoretical center of the stator cavity. During the simulated load or operation monitoring phase, a second control command is generated based on the dynamic changes in the air gap data to drive the stator displacement drive device to control the stator support and fine-tuning platform to perform follow-up compensation movement, so as to counteract the air gap unevenness caused by rotor displacement and realize the dynamic maintenance of the air gap. The multiple non-contact displacement sensors in the air gap measuring device are symmetrically and uniformly arranged at N points along the inner circumference of the stator, where N is an even number greater than or equal to 4. Each sensor is used to synchronously measure the actual air gap value at its installation location and transmit the actual air gap value to the central control module; The central control module is further configured as follows: Obtain the target air gap value for the motor; Calculate the air gap deviation value at each measurement point based on the actual air gap value and the target air gap value at each measurement point; Based on the air gap deviation values ​​measured by at least one set of symmetrically arranged sensors, the real-time eccentricity vector of the rotor center relative to the stator center in the horizontal plane is calculated. The real-time eccentricity vector includes a first eccentricity component in a first direction and a second eccentricity component in a second direction. The first control command and the second control command are both generated based on the first eccentric component and the second eccentric component, and are used to control the stator displacement driving device to drive the stator support and fine-tuning platform to move in the direction that cancels the real-time eccentric vector. The central control module is further configured to generate displacement commands using a control algorithm that includes proportional and / or derivative elements. The formula for calculating the command displacement of the stator support and fine-tuning platform in the first direction is configured as follows: ； The formula for calculating the command displacement of the stator support and fine-tuning platform in the second direction is configured as follows: ； in, , These are the command displacement amounts in the first direction and the command displacement amounts in the second direction, respectively. , These are the first eccentric component and the second eccentric component, respectively. , These are the proportional gains in the first and second directions, respectively. , These are the differential gains in the first and second directions, respectively. , These are the rates of change of the eccentric components in the first and second directions, respectively; Furthermore, the control algorithm integrates dead zone judgment logic: when the absolute value of any eccentric component is less than a first preset threshold, the eccentric component is set to zero.

2. The system according to claim 1, characterized in that, The stator displacement drive device is a multi-degree-of-freedom micro-motion adjustment mechanism, including a high-precision servo electric cylinder or linear motor arranged in a first and second direction that are perpendicular to each other in the horizontal plane. The drive unit in each direction integrates a force sensor and a position encoder.

3. The system according to claim 1, characterized in that, The rotor hoisting and centering module includes a gantry crane, an anti-torsion lifting device, a multi-dimensional attitude adjustment mechanism, and a magnetic balance auxiliary device. The magnetic balancing auxiliary device is a movable high-permeability shielding plate or a controllable reverse electromagnetic coil group set between the stator and the rotor, used to partially cancel or shield the strong magnetic attraction between the two during the process of the rotor being hoisted close to the stator.

4. The system according to claim 1, characterized in that, The displacement detection device includes a high-precision grating ruler or laser tracker installed between the stator support and fine-tuning platform and the base platform, used to provide full closed-loop feedback of the macroscopic displacement of the stator support and fine-tuning platform.

5. The system according to claim 3, characterized in that, The stator support and fine-tuning platform is also equipped with a strong magnetic shock protection locking mechanism. During the non-adjustment phase, the strong magnetic shock protection locking mechanism mechanically locks the stator support and fine-tuning platform to the base platform to prevent the stator from moving unexpectedly due to the sudden attraction force generated by the rotor's strong magnetic field.

6. A method for assembling the stator and rotor of a permanent magnet suspended hoist motor and maintaining the air gap, applied to the system of claim 5, characterized in that, include: Step S1: Fix the stator to the stator support and fine-tuning platform, and activate the anti-strong magnetic impact locking mechanism to lock the platform position; Step S2: Operate the rotor hoisting and centering module to smoothly hoist the rotor to the initial position in the stator cavity. During this process, the magnetic balancing auxiliary device is activated to reduce the influence of strong magnetic attraction. Step S3: Release the locking state of the anti-magnetic impact locking mechanism and start the air gap measuring device and displacement detection device; The central control module reads the initial air gap data. If the magnitude of the calculated initial eccentric vector is greater than the second preset threshold, it generates and executes the first control command to drive the stator displacement drive device to adjust the stator position until the magnitude of the eccentric vector is less than or equal to the second preset threshold, thus completing the static alignment of the rotor in the stator cavity. Step S4: Under simulated rotor loading or actual operating conditions, the central control module continuously monitors the air gap data. When it detects that the air gap changes due to simulated load or operating conditions and the recalculated real-time eccentricity vector exceeds the third preset threshold, it automatically generates and executes the second control command to drive the stator displacement drive device to control the stator support and fine-tuning platform to perform follow-up compensation adjustment, so that the air gap value is restored and kept uniform.

7. The method according to claim 6, characterized in that, In step S4, the simulated load is achieved by applying a controllable radial force or torque to the rotor shaft end; the third preset threshold is less than or equal to the second preset threshold.

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