Suspension direct-drive portal crane system

Abstract

The invention relates to the technical field of electric vehicle power devices, in particular to a suspension direct-drive portal crane system. A fractional slot magnetic conductance modulation module adopts fractional slot magnetic conductance modulation to reduce pulsation of cogging force; the cogging force calculation module carries out periodic continuation on a primary iron core of the permanent magnet linear motor by taking the existing cogging number as the basic length; the end part acting force calculation and optimization module obtains the magnitude of the end part acting force when the primary lengths are different by using a finite element; a magnetic resistance calculation module of the permanent magnet linear motor establishes a slotted model and a slotless model, changes the primary length and then parameterizes the secondary position; the permanent magnet linear motor rotor potting module uses a potting material and performs potting treatment on a permanent magnet linear motor through a potting process, adopts a magnetic suspension linear motor for direct driving, and has the advantages of few transmission parts, compact structure, high reliability, small size, small track abrasion, long service life and low operation noise.

Description

Technical Field

[0001] This invention relates to the field of electric vehicle power unit technology, and in particular to a suspended direct-drive gantry system. Background Technology

[0002] With the advancement of technology and the acceleration of the pace of life, automatic doors have gradually become an important functional component of various buildings, vehicles, and automated equipment, possessing a huge market size and development prospects.

[0003] Currently, conventional sliding door operators often use indirect drive technology with a rotary motor and belt to convert the rotational motion of the motor into the linear motion of the door leaf.

[0004] Due to wear in the intermediate transmission links, the transmission efficiency, speed and life are limited, making it unsuitable for high-speed or heavy-load applications. It also has a high failure rate, is prone to slippage, and requires frequent maintenance or replacement of components such as belts and pulleys. Summary of the Invention

[0005] The purpose of this invention is to provide a suspended direct-drive door operator system, which adopts a magnetic levitation linear motor for direct drive, with fewer transmission components, compact structure, high reliability, small size, low track wear, long service life, and low operating noise.

[0006] To achieve the above objectives, the present invention provides a suspended direct-drive gantry crane system, comprising:

[0007] The fractional slot magnetic permeability modulation module uses fractional slot magnetic permeability modulation to reduce the pulsation of cogging force, so as to ensure that the back electromotive force of the motor has a good sinusoidal waveform and weaken the cogging force of the motor.

[0008] The cogging force calculation module extends the primary core of the permanent magnet linear motor with the existing number of cogging teeth as the basic length, transforming the model of the permanent magnet linear motor into a motor model with infinite lengths for both the primary and secondary windings, and then analyzes only one cycle.

[0009] The end force calculation and optimization module uses finite element method to obtain the magnitude of the end force when the primary length is different.

[0010] The reluctance calculation module for permanent magnet linear motors is developed by establishing slotted and slotless models and changing the primary length, and then parameterizing the secondary position.

[0011] The permanent magnet linear motor mover potting module uses potting materials and a potting process to pot the permanent magnet linear motor.

[0012] The fractional slot magnetic permeability modulation module adopts a winding design of a seven-stage six-slot permanent magnet linear motor.

[0013] The end force calculation and optimization module calculates every 4 mm between 650 and 670 mm of core length.

[0014] The potting materials for the permanent magnet linear motor mover potting module include epoxy resin, vinyl ester resin, unsaturated polyester, and phenolic resin.

[0015] The specific steps of the potting process for the permanent magnet linear motor mover potting module are as follows:

[0016] Selecting matrix materials and reinforcing fibers;

[0017] The permanent magnet linear motor is subjected to preheating, vacuuming, potting and curing processes in sequence.

[0018] Cool the potted permanent magnet linear motor;

[0019] After performance testing, the finished permanent magnet linear motor was obtained.

[0020] This invention discloses a suspended direct-drive gantry motor system. A fractional-slot magnetic permeability modulation module reduces cogging force pulsation to ensure a good sinusoidal waveform for the motor's back electromotive force and weakens the cogging force. A cogging force calculation module extends the primary core of the permanent magnet linear motor periodically using the existing number of slots as the basic length, converting the permanent magnet linear motor model into a model with infinitely long primary and secondary windings, and then analyzes only one cycle. An end-force calculation and optimization module uses finite element analysis to determine the magnitude of the end-force when the primary winding length varies. A permanent magnet linear motor reluctance calculation module establishes slotted and slotless models and changes the primary winding length, then parameterizes the secondary winding position. A permanent magnet linear motor mover potting module uses potting material and a potting process to pot the permanent magnet linear motor. The system employs a magnetically levitated linear motor for direct drive, resulting in fewer transmission components, a compact structure, high reliability, small size, low track wear, long lifespan, and low operating noise. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0022] Figure 1 This is a magnetic permeation distribution diagram of a 7-pole, 6-slot permanent magnet linear motor in a suspended direct-drive door operator system according to the present invention.

[0023] Figure 2 This is a diagram of the tooth groove force analysis model of a suspended direct drive gantry system according to the present invention.

[0024] Figure 3 This is a magnetic field distribution diagram of a suspended direct-drive door operator system according to the present invention.

[0025] Figure 4 This is a waveform diagram of the end force applied at 650-670mm in a suspended direct drive door operator system according to the present invention.

[0026] Figure 5 This is a waveform diagram of the end force applied at 655-661 mm in a suspended direct drive door operator system according to the present invention.

[0027] Figure 6 This is a curve showing the variation of the peak value of the end force of a suspended direct drive gantry crane system of the present invention with the length of the iron core.

[0028] Figure 7 This is a calculation curve of the tooth groove force, end force and magnetic resistance of a suspended direct drive gantry system of the present invention.

[0029] Figure 8 This is a schematic diagram of thrust fluctuation values ​​for different end sizes of a suspended direct-drive gantry crane system according to the present invention.

[0030] Figure 9 This is a test diagram of the magnetic resistance of a suspended direct-drive gantry system according to the present invention.

[0031] Figure 10 This invention relates to a tile-shaped magnetic pole structure (left) for a suspended direct-drive gantry crane system.

[0032] Figure 11 This is a sinusoidal magnetic pole structure (right) of a suspended direct-drive door operator system according to the present invention.

[0033] Figure 12 This is a flow chart of the glue-filling process for a suspended direct-drive gantry crane system according to the present invention. Detailed Implementation

[0034] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0035] Please see Figures 1-12 , Figure 1 This is a magnetic permeation distribution diagram of a 7-pole, 6-slot permanent magnet linear motor in a suspended direct-drive gantry crane system according to the present invention. Figure 2 This is a diagram of the cogging force analysis model of a suspended direct-drive gantry crane system according to the present invention. Figure 3 This is a magnetic field distribution diagram of a suspended direct-drive gantry system according to the present invention. Figure 4 This is a waveform diagram of the end force applied at 650-670mm in a suspended direct-drive gantry crane system according to the present invention. Figure 5 This is a waveform diagram of the end force applied at 655-661 mm in a suspended direct-drive gantry crane system according to the present invention. Figure 6This is a curve showing the peak-to-peak value of the end force of a suspended direct-drive gantry crane system according to the present invention as a function of the core length. Figure 7 This is a calculation curve of the cogging force, end force, and magnetic resistance of a suspended direct-drive gantry crane system according to the present invention. Figure 8 This is a schematic diagram illustrating the thrust fluctuation values ​​of a suspended direct-drive gantry crane system of the present invention at different end dimensions. Figure 9 This is a test diagram of the magnetic resistance of a suspended direct-drive gantry crane system according to the present invention. Figure 10 This invention relates to a tile-shaped magnetic pole structure (left) for a suspended direct-drive gantry crane system. Figure 11 This invention relates to a sinusoidal magnetic pole structure (right) for a suspended direct-drive gantry system. Figure 12 This is a flow chart of the potting process for a suspended direct-drive gantry crane system according to the present invention. The present invention provides a suspended direct-drive gantry crane system, comprising:

[0036] The fractional-slot magnetic permeability modulation module reduces cogging force pulsation to ensure a good sinusoidal waveform for the motor's back EMF and weaken the cogging force. Considering manufacturing processes and economics, many techniques are rarely used in actual motor designs. It should also be noted that while many measures reduce cogging force, they also reduce electromagnetic force, but electromagnetic force pulsation increases accordingly. Therefore, a comprehensive consideration of thrust pulsation is necessary, taking into account both cogging force and electromagnetic force pulsation. By comprehensively considering various factors, fractional-slot magnetic permeability modulation reduces cogging force pulsation, ensuring a good sinusoidal waveform for the motor's back EMF while weakening the cogging force. The advantages of using a multi-pole, low-tooth structure are also discussed. Figure 1 The winding design and connection of a 7-pole 6-slot permanent magnet linear motor are presented. Through winding calculation, it is found that the motor has a high fundamental winding factor and a small harmonic winding factor. The back EMF waveform of the motor is analyzed and calculated by finite element method, and a back EMF waveform with good sinusoidal characteristics is obtained, which ensures very small electromagnetic force pulsation and weakens cogging force.

[0037] The cogging force calculation module extends the primary core of the permanent magnet linear motor periodically using the existing number of slots as the basic length, transforming the model into a motor model with infinitely long primary and secondary windings. Only one cycle is analyzed. Since the designed permanent magnet linear motor uses a concentrated winding with fractional slots, analytical methods are extremely difficult; therefore, finite element numerical analysis of cogging force is employed. Because the linear motor has a discontinuous structure, appropriate processing of the permanent magnet linear motor model is necessary when analyzing only the cogging force caused by the cogging effect. Therefore, the primary core of the permanent magnet linear motor is periodically extended using the existing number of slots as the basic length, transforming the model into a motor model with infinitely long primary and secondary windings, and then analyzing only one cycle. The boundary conditions on the top and bottom sides are zero magnetomotive force, while the left and right sides are periodic boundary conditions. Figure 2 and Figure 3 As shown.

[0038] The end force calculation and optimization module uses the finite element method (FEM) to determine the magnitude of the end force for different primary core lengths. The phase difference of the end force has a subtle relationship with the primary core length, and its regular variation is difficult to derive analytically. The FEM method can then be used to determine the magnitude of the end force for different primary core lengths. To reduce the computational workload, calculations are performed every 4 mm within the 650–670 mm core length range. Figure 4 As shown. From Figure 6 As can be seen, the amplitude is smallest when the primary core length is 658 mm. To further refine the influence of end length on thrust fluctuation, finite element analysis was performed within the range of small amplitude. Figure 5 Finite element analysis (FEM) models of core lengths ranging from 655 to 661 mm are presented. To clearly illustrate the influence of core length on thrust fluctuation, Figure 6 The peak-to-peak value within a pair of pole gaps is given as a function of core length. Clearly, there exists a minimum value of 193 N, at which point the core length is 658 mm.

[0039] The reluctance calculation module for permanent magnet linear motors (PMLMs) establishes slotted and slotless models, modifies the primary winding length, and then parameterizes the secondary winding position. One of the main sources of thrust fluctuation in PMLMs is reluctance. The calculation and optimization of cogging force and end force in PMLMs have been discussed previously; based on this, thrust fluctuations can be analyzed. This is achieved by establishing slotted and slotless models, changing the primary winding length, and then parameterizing the secondary winding position. Figure 7 The magnetic reluctance, cogging force, and end force fluctuations were obtained, and then the case with the smaller magnetic reluctance was selected. Since the changes in the length and height of the end directly affect the changes in the end magnetic permeability, the length and height of the end were parameterized using finite element method. By comparing and optimizing the primary length, shape, and slot size, the magnetic reluctance was minimized, and the cogging force fluctuation was 3.2%. Figure 8 The graph shows the maximum thrust fluctuation variation when the end dimensions change. It can be seen that changes in the width and height of both ends significantly affect the maximum thrust fluctuation, and there is a minimum value for optimization. Simulations show that the maximum thrust fluctuation reaches its minimum of 130N when the end width is 30mm and the bottom is 2mm from the air gap. To verify the effectiveness of the analysis, a permanent magnet linear motor with an end width of 7mm and a bottom distance of 4mm from the air gap was tested for magnetic resistance. During the magnetic resistance test, the motor's three-phase power was not supplied. The motion table moved left and right via a servo motor and lead screw transmission. Force sensors collected data at various points during the motor's movement, and the force fluctuation was shown below. Figure 9As shown in Table 1, the maximum magnetic resistance during the entire test process is given. Other methods, including permanent magnet segmentation and skewed pole methods, can also suppress torque pulsation. Changing the shape of the permanent magnet weakens or cancels the Nth harmonic in the cogging torque, thereby reducing the sinusoidal distortion rate of the magnetic flux density waveform in the motor air gap, and thus suppressing the cogging torque.

[0040] Test parameters unit positive Reverse friction N -264.37 284.24 Alveolar force N -320.69 328.03 STD 71.83 75.09

[0041] Table 1 Magnetic Resistivity Test Table

[0042] The permanent magnet linear motor mover potting module uses potting materials and a potting process to pot the permanent magnet linear motor. During linear motor operation, ohmic losses in the stator windings generate heat, and eddy current losses in the mover also generate heat; therefore, the potting material should have good thermal conductivity. Potting matrix materials include epoxy resin, vinyl ester resin, unsaturated polyester, and phenolic resin. Reinforcing fibers such as glass fiber, carbon fiber, boron fiber, aramid fiber, and silicon carbide fiber can be used to improve strength and thermal conductivity. The construction process affects the potting quality and performance, and the process varies depending on the protective material. Vacuuming is particularly important during encapsulation. Before vacuuming, the following parameters must be strictly controlled: sealant preparation, sealant viscosity, effective working time of the sealant, air gap between the stator / rotor and the tooling, workpiece dehumidification, workpiece preheating to ensure the fluidity of the sealant, and preheating temperature and time. During vacuuming, the following parameters must be strictly controlled: vacuuming temperature, vacuuming speed, final vacuum level, vacuum holding time, and number of vacuuming cycles. After vacuuming, the workpiece levelness, workpiece pre-baking, and final drying temperature and time must be controlled. Epoxy resin can be injection molded. The stator is placed in a mold, epoxy is injected, and air is removed by vacuuming to increase the insulation and thermal conductivity of the epoxy resin. The final encapsulated workpiece is inspected for air bubbles using ultrasonic testing technology.

[0043] This invention discloses a suspended direct-drive gantry crane system, employing optimized design technology for high thrust density, low thrust fluctuation, and low cost permanent magnet linear motors. Based on the performance requirements of high integration, lightweight, high precision, and near-zero heat dissipation in the gantry crane motion system, it proposes applying high-abundance rare-earth permanent magnet materials with high remanence, low coercivity, and low cost to the linear motor, thereby reducing its cost. To overcome the limitations of low-cost, high-thrust, and low-thrust-fluctuation permanent magnet linear motors, the topology of permanent magnet linear motors based on high-abundance rare-earth permanent magnet materials is studied. An accurate electromagnetic model is constructed, and the Maxwell tensor method is used to accurately calculate the three-dimensional forces of the permanent magnet linear motor, including electromagnetic thrust, lateral force, and normal force, and to deeply analyze their coupling mechanism. The electromagnetic design of the permanent magnet linear motor is based on a field-circuit combination method using vector control. To effectively suppress high-order harmonics, reduce thrust fluctuation, and maintain high thrust, a combination of the fast non-dominated sorting genetic algorithm NSGA-II and the support vector machine (SVM) model is proposed to perform multi-objective optimization of thrust density and thrust fluctuation for the high-abundance rare-earth permanent magnet linear motor, achieving high-thrust, high-precision, and stable operation. Simultaneously employing a multi-objective electromagnetic optimization design technique for both horizontal thrust and vertical normal attraction: This requires not only meeting the speed and acceleration requirements for linear drive of a specific load, i.e., satisfying the required horizontal thrust, but also adjusting and optimizing the permanent magnet normal attraction of the linear motor for that specific load. This aims to balance the weight of all moving parts as much as possible through normal attraction while ensuring horizontal electromagnetic thrust, thereby minimizing the load on the guide rail support. Therefore, it is essential to overcome the limitations of multi-objective electromagnetic optimization design techniques for both horizontal thrust and vertical normal attraction. Combining analytical and finite element methods, this project completed the multi-objective electromagnetic optimization design of the linear motor's horizontal thrust and vertical normal attraction, ensuring that the vertical normal attraction of the linear motor equals the expected total weight of the moving parts, while simultaneously satisfying the horizontal thrust requirement. In addition, high dynamic response gantry crane linear motor servo drive technology is adopted: To meet the project requirements of ultra-fast linear drive, in addition to strengthening hardware aspects such as fast signal detection and AD conversion, high-speed network communication, and electromagnetic compatibility design, the focus is on innovation in the drive algorithm. This is mainly reflected in: using an extended Kalman filter algorithm to achieve online identification of motor resistance and flux linkage and dynamically adjust controller parameters, improving the adaptability to environmental changes such as temperature and enhancing servo performance; using the least squares method to estimate parameters such as motor mass and viscous friction system, automatically adjusting the speed loop gain, reducing servo configuration complexity, and improving the system's anti-interference capability; employing position domain-based thrust fluctuation compensation to accurately eliminate the influence of thrust fluctuations at different motor positions, improving control accuracy; using a fuzzy interference observer to observe and compensate for motor thrust in real time, improving the system's dynamic response and servo accuracy; and using a state feedback prediction algorithm to predict, correct, and compensate for time-delay disturbances such as measurement and transmission, increasing the system's phase margin and improving the stability and dynamic response speed of the servo drive.

[0044] The above-disclosed embodiments are merely one or more preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art can understand that implementing all or part of the above embodiments and making equivalent changes in accordance with the claims of this application still fall within the scope of this application.

Claims

1. A suspended direct-drive gantry crane system, characterized in that, include: The fractional slot magnetic permeability modulation module uses fractional slot magnetic permeability modulation to reduce the pulsation of cogging force, so as to ensure that the back electromotive force of the motor has a good sinusoidal waveform and weaken the cogging force of the motor. The cogging force calculation module extends the primary core of the permanent magnet linear motor with the existing number of cogging teeth as the basic length, transforming the model of the permanent magnet linear motor into a motor model with infinite lengths for both the primary and secondary windings, and then analyzes only one cycle. The end force calculation and optimization module uses finite element method to obtain the magnitude of the end force when the primary length is different. The reluctance calculation module for permanent magnet linear motors is developed by establishing slotted and slotless models and changing the primary length, and then parameterizing the secondary position. The permanent magnet linear motor mover potting module uses potting materials and a potting process to pot the permanent magnet linear motor.

2. The suspended direct-drive gantry crane system as described in claim 1, characterized in that, The fractional slot magnetic permeability modulation module adopts a winding design of a seven-stage, six-slot permanent magnet linear motor.

3. The suspended direct-drive gantry crane system as described in claim 2, characterized in that, The end force calculation and optimization module performs calculations every 4 mm between 650 and 670 mm of core length.

4. The suspended direct-drive gantry crane system as described in claim 3, characterized in that, The potting materials for the permanent magnet linear motor mover potting module include epoxy resin, vinyl ester resin, unsaturated polyester, and phenolic resin.

5. The suspended direct-drive gantry crane system as described in claim 4, characterized in that, The specific steps of the potting process for the permanent magnet linear motor mover potting module are as follows: Selection of matrix materials and reinforcing fibers; The permanent magnet linear motor is subjected to preheating, vacuuming, potting and curing processes in sequence. Cool the potted permanent magnet linear motor; After performance testing, the finished permanent magnet linear motor was obtained.

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