Combined permanent magnet synchronous linear motor with end permanent magnet assistance

Abstract

The invention provides an end permanent magnet assisted combined permanent magnet synchronous linear motor. The end permanent magnet assisted combined permanent magnet synchronous linear motor comprises a combined primary, a combined secondary and an air gap, the combined primary is formed by continuously installing a plurality of unit primary bodies end to end, and each unit primary body comprises a primary iron core and an armature winding installed in a unit primary body groove; end magnetism adjusting blocks are arranged at the two ends of the combined primary, and each end magnetism adjusting block comprises end iron cores fixed to the two ends of the combined primary and a plurality of end permanent magnets embedded into the lower surfaces of the end iron cores; the end magnetism adjusting blocks generate enhanced end effect force which is consistent with the cogging effect force in harmonic amplitude and opposite to the cogging effect force in phase, and magnetic resistance caused by the cogging effect of the combined primary is offset on the whole. The installation space is effectively utilized, and the power is improved; and the thrust fluctuation is reduced by adopting the end magnetism adjusting blocks designed in a targeted manner, and the comprehensive requirements of power improvement and thrust fluctuation suppression are met.

Description

Technical Field

[0001] This application relates to the field of permanent magnet linear synchronous motor technology, and in particular to a combined permanent magnet synchronous linear motor with end permanent magnet assistance. Background Technology

[0002] Permanent magnet synchronous linear motors (PMSMs) are widely used in high-power applications such as vertical lifting and electromagnetic catapults due to their advantages of high thrust density, good power performance, and simple structure. However, a single PMSM is insufficient to meet the ever-increasing power and thrust demands of these applications. Therefore, multi-module PMSMs are often required to meet these high-power requirements. Existing technologies for improving output power and suppressing thrust fluctuations in multi-module PMSMs include spacing between multiple moving units, optimization of unit motor end teeth, and displacement of bilateral moving unit modules. For example, invention CN115995934B proposes a multi-moving unit combined linear motor with a long primary and short secondary. By setting the spacing between adjacent moving units, their positioning force fluctuations cancel each other out, thereby suppressing overall thrust fluctuations. However, in applications such as vertical lifting, the installation space for PMSMs is limited. While the aforementioned multi-module PMSM spacing strategy can improve power and suppress thrust fluctuations, it significantly increases the total length of the motor, increases the complexity of assembly and manufacturing, and reduces space utilization.

[0003] To address this issue, a continuous, seamless installation of closely spaced moving parts is an effective solution. However, the combined permanent magnet synchronous motor (PMSM) constructed by continuously installing unit module PMSM linear motors results in significant changes in the thrust fluctuation composition. Thrust fluctuation primarily originates from magnetic drag, including end effect forces (…). (abbreviated as end force) and cogging effect force ( (Also known as cogging force). In modular motors, end forces usually dominate; however, when N modules are arranged consecutively, the end effect of the intermediate motor module is eliminated due to the continuity of the magnetic field, and the total end force is still approximately equal to the end force of a single module. Conversely, the cogging force of each module ( Due to phase consistency, they almost completely superimpose, increasing the total cogging force to The total magnetic reluctance of the system can be expressed as: ; Clearly, as the number of modules N increases, cogging force becomes the primary source of thrust fluctuation. Existing thrust fluctuation suppression methods for single motors typically rely on end forces, primarily focusing on reducing or balancing cogging forces by adjusting the primary core length or adding auxiliary teeth to weaken the end forces, thereby suppressing overall thrust fluctuation. For example, the positioning force suppression method for permanent magnet synchronous linear motors proposed in invention CN116961514A suppresses thrust fluctuation by balancing the fundamental component of the end forces with the optimized cogging force component. However, in combined permanent magnet synchronous linear motors with multiple unit motors installed consecutively, cogging forces dominate, and using weakening end forces to compensate for or balance cogging forces is insufficient to effectively address the thrust fluctuation problem of combined permanent magnet synchronous linear motors. Summary of the Invention

[0004] The purpose of this application is to provide a combined permanent magnet synchronous linear motor with end permanent magnet assistance to solve or alleviate the problems existing in the prior art.

[0005] To achieve the above objectives, this application provides the following technical solution: This application provides a combined permanent magnet synchronous linear motor with end permanent magnet assistance, including a combined primary and a combined secondary located directly below the combined primary, with an air gap between the combined primary and the combined secondary; the combined primary is formed by continuously installing several unit primarys end to end, each unit primary including a primary core and an armature winding installed in a slot of the unit primary; end magnetic adjustment blocks are provided at both ends of the combined primary, each end magnetic adjustment block including end cores fixed at both ends of the combined primary and several end permanent magnets embedded in the lower surface of the end cores; the end magnetic adjustment blocks generate an enhanced end effect force with the same amplitude and opposite phase as the cogging effect force harmonic, thereby canceling out the magnetic resistance caused by the cogging effect of the combined primary as a whole.

[0006] Furthermore, the number of end permanent magnets embedded in each end core is one or more; the end core is a rectangular block, and the end permanent magnet is a rectangular strip or an arc-shaped strip.

[0007] Furthermore, the end core is solid or has one or more cavities extending in the front-to-back direction.

[0008] Furthermore, each of the end cores has an end permanent magnet attached to or embedded on its lower surface, and the magnetization direction of the end permanent magnets on the two end cores is vertical, and the magnetization directions are the same or opposite.

[0009] Furthermore, each of the ends of the lower surface of the end core has a permanent magnet attached to or embedded at both ends. The magnetization directions of the two permanent magnets in the same end core are vertical, and the magnetization directions are the same or opposite.

[0010] Furthermore, the cavity is composed of one or more unit cavities; the shape and position of the cavity are obtained through finite element simulation analysis.

[0011] Furthermore, the cavity is located at one or more positions on the left side, right side, and lower surface of the end core, such that the surface of the end core with the cavity is recessed inward.

[0012] Furthermore, the design steps for the end magnetic adjustment block are as follows: S1. Using the single-variable scanning method, the influence of changes in the end core structural parameters on the end effect force is analyzed, and the maximum range of the end effect force adjusted by the key structural parameters of the end core is determined. Based on the characteristic that the combined permanent magnet synchronous linear motor has only two ends, the cogging force of different numbers of combined permanent magnet synchronous linear motors is analyzed by finite element simulation. If the cogging force exceeds the maximum end effect force, an end magnet adjustment block with end permanent magnet assistance is required. S2. Add end permanent magnets to the finite element simulation model. Similarly, perform parametric scanning through finite element simulation to determine the size, quantity, and position of the end permanent magnets that satisfy the condition that the amplitude of the end effect force after adding permanent magnets is equal to the amplitude of the cogging effect force of the combined linear motor.

[0013] Furthermore, the design steps for the end-mounted magnetic adjustment block include: The magnetic reluctance of a combined permanent magnet synchronous linear motor can be quickly solved using a finite element simulation model. Based on the cogging force amplitude, the height, width, and position of the end permanent magnet are determined using a single-parameter scanning method. Different digital matrices are used to characterize the material composition and shape of the end magnetizer. The thrust and thrust fluctuation under different end magnetizer shapes are used as optimization objectives. A genetic algorithm is used to quickly find the optimal shape, and the optimal shape is selected based on the obtained Pareto front plot.

[0014] To address the issue of low space utilization, this application employs a method of tightly arranged, seamless mounting of linear motors using mover modules. By first uniformly designing and fabricating the unit motor modules, and then separately designing and fabricating the end areas, the overall assembly difficulty of the combined motors is reduced, and the total length of the movers is further shortened, significantly improving space utilization and structural compactness.

[0015] In response to the problem that the cogging force is dominant in combined permanent magnet synchronous linear motors with multiple unit motors installed continuously, and that the method of weakening the end force to compensate for or balance the cogging force cannot effectively deal with the thrust fluctuation of the combined permanent magnet synchronous linear motor, this invention proposes an end permanent magnet auxiliary method to balance the cogging force.

[0016] Its working principle is as follows: By extending permanent magnet-assisted end-mounted magnetic adjustment blocks at the ends of the combined permanent magnet synchronous linear motor, the amplitude of the end force is increased. Based on this, according to the harmonic order, amplitude, and phase of the cogging force, the structural parameters of the permanent magnet-assisted end-mounted magnetic adjustment blocks are optimized using a finite element method and a genetic algorithm. This includes adjusting the size and position of the end permanent magnets, as well as the position, size, and shape of the cavities, to achieve phase offset modulation of the end force. Ultimately, an actively enhanced end force with an amplitude essentially consistent with but opposite phase to the cogging force is generated, thereby suppressing the magnetic reluctance of the combined permanent magnet synchronous linear motor. This method can significantly improve the smoothness and stability of motor operation, which is beneficial for improving control accuracy, reducing vibration and noise, and effectively reducing thrust fluctuations in the combined linear motor.

[0017] The technical solution of this application has the following beneficial effects: This application utilizes a multi-mover continuous installation method to arrange permanent magnet synchronous linear motors, reducing the installation space with the shortest continuous mover length, thus achieving efficient use of installation space and increased power. At the same time, by using end-mounted permanent magnet-assisted end-mounted magnetic adjustment blocks, an active enhancement modulation end-mounted effect method is used to suppress the increased magnetic resistance due to the combination of unit motor modules. This effectively solves the problem of large thrust fluctuation caused by the multiplication of cogging force when the combined permanent magnet synchronous linear motor is continuously installed, significantly reducing thrust fluctuation and meeting the comprehensive requirements of power increase and thrust fluctuation suppression. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. Wherein: Figure 1 This is a schematic diagram of the structure of a combined permanent magnet synchronous linear motor according to an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of the structure of a unit motor module of a combined permanent magnet synchronous linear motor according to an embodiment of the present invention.

[0020] Figure 3 This is a performance analysis diagram of the unit motor module in an embodiment of the present invention.

[0021] Figure 4 The diagram shows the end effect force waveform when the number of unit motor modules is different in an embodiment of the present invention.

[0022] Figure 5 The diagram shows the cogging force waveform when the number of unit motor modules is different in an embodiment of the present invention.

[0023] Figure 6The diagram shows the reluctance waveforms when the number of unit motor modules varies in an embodiment of the present invention.

[0024] Figure 7 This is a waveform diagram of the end effect force when the length of the primary core is different in an embodiment of the present invention.

[0025] Figure 8 This is a schematic diagram of the end magnetic adjustment block in an embodiment of the present invention; wherein (a)-(h) are end magnetic adjustment blocks with different structures.

[0026] Figure 9 The finite element optimization method is used for the combined motor with end permanent magnet assistance in the embodiment.

[0027] Figure 10 This is a comparison diagram of the end effect force before and after the installation of the end magnetic adjustment block in an embodiment of the present invention.

[0028] Figure 11 This is a comparison diagram of thrust fluctuations before and after the installation of the end magnetic adjustment block in an embodiment of the present invention.

[0029] Explanation of reference numerals in the attached figures: 1-Primary unit, 11-Primary core, 12-Armature winding, 13-Secondary unit, 21-Secondary core, 22-Secondary permanent magnet, 3-Air gap, 4-End adjustment block, 41-End core, 42-End permanent magnet, 43-Cavity. Detailed Implementation

[0030] The present application will now be described in detail with reference to the accompanying drawings and embodiments. Various examples are provided by way of explanation and not by way of limitation. In fact, those skilled in the art will recognize that modifications and variations can be made to the present application without departing from the scope or spirit thereof. For example, a feature shown or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is desirable that the present application encompass such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing embodiments of this disclosure only and is not intended to limit this disclosure.

[0032] In the description of this application, the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and do not require this application to be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0033] like Figure 1 , Figure 2 As shown, a combined permanent magnet synchronous linear motor with end permanent magnet assistance includes a combined primary and a combined secondary located directly below the combined primary, with an air gap 3 between the combined primary and the combined secondary. The combined primary is formed by continuously installing several unit primary 1s end to end, each unit primary 1 consisting of a primary iron core 11 and an armature winding 12 installed in a slot of the unit primary 1. The combined secondary is formed by connecting several unit secondary 13s end to end, each unit secondary 13 consisting of a secondary iron core 21 and a secondary permanent magnet 22. The unit primary 1s adopt an alternating N / S structure, and the width of each secondary permanent magnet 22 is the same (width refers to...). Figure 1 (The width in the left and right directions); one primary unit 1 and one secondary unit 13 constitute one unit motor module. Figure 2 The diagram schematically depicts a unit motor module; the two ends of the combined primary are provided with end adjustment blocks 4, the end adjustment blocks 4 include end iron cores 41 fixed at both ends of the combined primary and several end permanent magnets 42 embedded in the lower surface of the end iron cores 41; the end adjustment blocks 4 generate an enhanced end effect force with the same amplitude and opposite phase as the cogging effect force harmonic, which cancels out the magnetic resistance caused by the cogging effect of the combined primary as a whole.

[0034] like Figure 1 , Figure 8As shown, the number of end permanent magnets 42 embedded in one end core 41 is one or more; the overall shape of the end core 41 is a rectangular block, and the end permanent magnets 42 are rectangular or arc-shaped blocks for ease of manufacture and installation. When one end permanent magnet 42 is embedded or surface-mounted on the lower surface of one end core 41, the magnetization direction of the end permanent magnets 42 on two end cores 41 is vertical, and the magnetization directions are the same or opposite; when one end permanent magnet 42 is surface-mounted or embedded at each end of the lower surface of each end core 41, the size and shape of the two end permanent magnets 42 in the same end core 41 can be different, such as one being a rectangular block and the other an arc-shaped block, or rectangular / arc blocks with different widths / heights. According to simulation results, there is no significant difference in the effect of using end forces of the same polarity and opposite polarity in the structure described in this application. When an end permanent magnet 42 is embedded or surface-mounted at both ends of the lower surface of one of the end cores 41, the magnetization directions of the two end permanent magnets 42 are vertical, and the magnetization directions are the same or opposite. The end core 41 is solid or has one or more cavities 43 extending in the front-back direction. The cavity 43 is composed of one or more unit cavities, and the vertical cross-section of the unit cavity can be rectangular, preferably square. The unit cavities can be obtained by processing the silicon steel sheets that make up the core. Specifically, the end core 41 and the end permanent magnet 42 are both optimized in shape using the finite element method and intelligent optimization algorithm. Combined with the position and shape of the cavity 43, the open boundary is smoothed to determine the final shape and position of the end magnetizing block 4. The finite element method can refer to the method of suppressing the magnetic resistance of a permanent magnet linear synchronous motor using an end magnetizing module in patent CN118611496A.

[0035] Figure 8 In (a)-(h), the end magnetizing blocks 4 have different structures; in (a)-(d), each end core 41 has one end permanent magnet 42 embedded or surface-mounted; in (e)-(h), each end core 41 has two end permanent magnets 42 embedded or surface-mounted; in (a), (c), (e), and (g), the end core 41 is a solid rectangle; in (b), the cavity 43 is located on the left and right sides of the end core 41 and is open on the sides, and the open boundary of the cavity 43 is smoothly treated, so that the left and right sides of the end core 41 form an arc shape. The depressions in (b), (d), (f), and (h) are achieved by optimizing the end magnetic adjustment blocks 4 of linear motors with different combinations. The end iron core 41 and the end permanent magnet 42 are improved by driving the intelligent optimization algorithm. Since it is a point-spreading method, there will be a structure with a cavity 43 inside the end iron core 41. In this embodiment, the end magnetic adjustment blocks 4 on the left and right are symmetrically arranged. In other cases, the optimized structures of the end magnetic adjustment blocks 4 on the left and right may also be asymmetrical.

[0036] The modular permanent magnet synchronous linear motor achieves a combined connection of multiple unit motor modules by closely arranging and continuously installing the primary unit 1 and the secondary unit 13 without gaps. In one embodiment, such as... Figure 2 The 3-slot 4-pole linear motor shown is a single motor module. Figure 3 This is a performance analysis diagram of the 3-slot, 4-pole unit motor module, mainly analyzing its magnetic reluctance, cogging force, end force, and thrust. The diagram shows that the end force (black square curve) and cogging force (red dot curve) fluctuate significantly. The magnetic reluctance (blue triangle curve) is a combined curve of the two forces. The fluctuations of the magnetic reluctance (blue triangle curve) and the motor thrust (green triangle curve) are consistent, exhibiting obvious alternating positive and negative changes. This indicates that the end force and cogging force are the main factors causing the thrust fluctuation. To reduce thrust fluctuation, it is necessary to focus on optimizing and controlling the end force and cogging force.

[0037] During assembly, the required number of unit motor modules is selected based on the preset thrust requirements and the thrust magnitude of the unit motor module itself. Without changing the connection method of the armature winding 12 of the unit motor module, the right side of the primary iron core 11 of one unit motor module is connected to the left side of the next unit motor module for assembly. Specifically, the combined permanent magnet synchronous linear motor with end permanent magnet assistance includes a back plate. The combined primary is fixed to the primary back plate with bolts. The end magnet adjustment module is installed on both sides of the combined primary iron core 11 and is fixed to the primary back plate with bolts after being aligned with the combined primary.

[0038] Figure 4 , Figure 5 , Figure 6 The waveforms of cogging force, magnetic resistance, and end force of the combined permanent magnet synchronous linear motor are shown for the number of unit motor modules being 1, 2, 3, 5, and 10, respectively. It can be seen that, since the shape of the end adjusting block 4 remains unchanged, as the number of unit motor modules increases, the number of cogging teeth in the combined linear motor increases exponentially. The cogging force of the combined linear motor is superimposed to n times the cogging force of the unit motor modules, causing an increase in the magnetic resistance of the combined linear motor and resulting in significant thrust fluctuations. Therefore, changing only the length of the primary iron core 11 has a limited effect on the change in end force of the combined linear motor; for example... Figure 7 The diagram shows the change in end force when the width of the end core 41 varies from 1 to 10 mm. The width of the primary core 11 is as follows: Figure 1 The width w1 of the end core 41 shown is shown, and the height h1 is shown. Figure 5 , Figure 7 The comparison of cogging forces shows that the change in end force caused by simply changing the length of the primary iron core 11 cannot cancel out the increased cogging force amplitude after the combination of the combined permanent magnet synchronous linear motor.

[0039] To further increase the end force amplitude, this application proposes to use an end adjustment block 4 with an end permanent magnet 42 as an auxiliary. By adding an extra permanent magnet, the magnetic field on both sides of the end can be further adjusted, increasing the end force on both sides of the combined permanent magnet synchronous linear motor, so that the end force amplitude is comparable to the cogging force amplitude of the combined permanent magnet synchronous linear motor.

[0040] The structure of the end-mounted magnetic adjustment block 4 needs to be specifically designed for each type of combined permanent magnet synchronous linear motor. For example... Figure 9 As shown, firstly, based on the preset thrust requirements, the required number of motor modules is selected according to the thrust magnitude of the unit motor module. Then, using an improved finite element simulation model, the combined PMSLM magnetoresistive system is quickly solved. Different digital matrices are used to represent different shapes of the end magnetizing block 4. With the thrust and thrust fluctuation under different shapes as optimization objectives, optimization algorithms such as genetic algorithms and intelligent optimization algorithms are used to quickly find the optimal shape. The optimal shape is selected based on the obtained Pareto front diagram. (If the end permanent magnet is an arc-shaped block, it is done as needed.) The boundary between the end permanent magnet 42 and the end iron core 41 is smoothed. Specifically, the finite element method includes the following steps: First, based on the actual dimensions of the combined permanent magnet synchronous motor, a suitable area to be processed is selected (the area to be processed is the range of the combined permanent magnet synchronous linear motor with end permanent magnet assistance of this application plus the range of a surrounding air bag, the length of the air bag is about 10mm longer than the linear motor, and the height is about 5mm higher). The preset area to be processed is divided using square grids of the same shape and size, where each square grid contains four triangles of the same shape; the four nodes and the intersection of the diagonals of the square grid are numbered and used as global numbers; the number of triangular grids contained inside the square grid and the internal nodes are numbered respectively, where the number of triangular grids is the global number, and the number of nodes inside the triangular grids is the local number, and the numbering is all in a counterclockwise direction; The process involves inputting the motor's geometric model, three-phase power supply, and required material properties using low-level code programming. Interpolation is performed based on pre-defined numbering information to establish matrix equations. The incomplete Choreski decomposition conjugate gradient method is used to solve for the vector magnetomotive force of the square grid nodes. The Newton-Rafaelsen method is used to iteratively solve the nonlinear problem. In each iteration, the matrix obtained in step 17 is used to solve for the matrix (step 17 involves reconstructing the mathematical model of the entire physical field (system matrix) based on the permeability of the end magnets of the current structure, and then iteratively solving it using the Newton-Rafaelsen method to obtain a more accurate magnetomotive force distribution). The nodal force method is used to calculate the electromagnetic force acting on the entire magnetic body by determining the electromagnetic force acting on each vertex within the magnetic body. Depending on the different magnetic permeability characteristics of different materials, such as Figure 9As shown, the end core 41 and cavity 43 (air) are represented by the numbers "1", "0" and "2" respectively, and the actual end permanent magnet assisted structure is characterized by a topological matrix composed of "1", "0" and "2". By arbitrarily arranging and combining the "1", "0", and "2" elements in the topological matrix, the complex and varied end-mounted permanent magnet assisted structure can be characterized. The goal is to obtain an enhanced end-mounted force with the same amplitude and opposite phase as the primary dominant cogging force, so that the cogging force of the combined PMSLM cancels out the adjusted end-mounted force, thereby reducing the overall magnetic drag and thrust fluctuation of the combined PMSLM and quickly solving for the optimal shape. In this embodiment, the unit motor module is 3 slots and 4 poles. The combined permanent magnet synchronous linear motor consists of 10 unit motor modules. By changing the shape of the end iron core 41, a corresponding magnetic resistance can be generated. The same magnetic resistance may correspond to several shapes of the end iron core 41. The length of the iron core that can generate the maximum end force is selected through finite element analysis. The height ratio of the end iron core 41 to the end permanent magnet 42 is 9:1. By changing the length of the end permanent magnet 42 ( Figure 1 Finite element simulation was performed on the length w1 in the left-right direction of the cavity 43 to determine the left-right length and position of the end permanent magnet 42. The shape of the cavity 43 is not necessarily rectangular; it can be regular or irregular, and the specific shape is determined through finite element analysis. Analysis showed that the permanent magnet embedded in the end core 41 performs better than the end permanent magnet 42 adhered to the surface. For this embodiment, Figure 8 The end-mounted adjusting block 4 in (e) works best. Afterwards, it is... Figure 8 Explanation of the finite element analysis of the structure in (e): Figure 8 (e) The middle permanent magnet 42 is located on the side of the end core 41 closest to the air gap 3. The end core 41 is rectangular in shape. The cogging force of the combined permanent magnet synchronous linear motor using this type of end adjusting magnet block 4 is shown in the figure. Figure 10 The green triangle in the image represents the end force curves before and after installation of the end adjusting magnetic block 4. Figure 10 The black square lines and red dot lines in the middle, and the thrust before and after optimization of the end-mounted magnetic block 4 are shown in the figure. Figure 11 The red and black lines clearly show that the end force increases after installing the end adjusting block 4, and the increase is greater than when only the primary iron core 11 is adjusted, indicating that the thrust fluctuation is smaller after optimization with the end adjusting block 4.

[0041] Figure 10The black square line represents the end force of the combined motor without the end adjusting magnetic block 4 installed. The blue triangle line represents the optimized situation when only the end core 41 is adjusted to increase the end force. After optimization, the maximum end force is achieved when the end core 41 is 10mm long and 18mm high, and the primary core 11 is 92mm long (the lengths of the end core 41 and the primary core 11 refer to...). Figure 1 As shown in the diagram (left and right lengths), comparing the cogging force (green triangles), it can be seen that although this method can increase the end force to some extent, the increase is less than that of the end force increase of the end adjusting block 4 with permanent magnets in this application, and is insufficient to suppress the cogging force. This application increases the end force by adding end permanent magnets 42. Based on the aforementioned embodiments, the added end permanent magnets 42 are all 2mm high and 2mm and 3mm long. Figure 10 The red dotted line represents the end force of the combined linear motor with the end adjusting magnetic block 4 fully installed. Compared to the previous two cases, the end force is significantly increased in this case, which can effectively counteract the cogging force.

[0042] This application adjusts the end magnetic field through an end-magnetic modulation module. Based on the harmonic order, amplitude, and phase of the cogging force, it modulates the end structural parameters to achieve end force phase shift, generating an actively enhanced end force with an amplitude essentially the same as but opposite in phase to the cogging force. This achieves reluctance suppression in the combined permanent magnet synchronous linear motor, making the motor operation smoother and more stable. It also improves the motor's control accuracy, reduces vibration and noise, and reduces thrust fluctuations in the combined linear motor. Figure 11 As shown.

[0043] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A combined permanent magnet synchronous linear motor with end permanent magnet assistance, characterized in that: The primary assembly includes a combined primary and a combined secondary located directly below the combined primary, with an air gap (3) between the combined primary and the combined secondary. The combined primary is formed by continuously installing several unit primarys (1) end to end. Each unit primary (1) includes a primary iron core (11) and an armature winding (12) installed in the slot of the unit primary (1). The combined primary is provided with end adjustment blocks (4) at both ends. The end adjustment blocks (4) include end iron cores (41) fixed at both ends of the combined primary and several end permanent magnets (42) embedded in the lower surface of the end iron cores (41). The end adjustment blocks (4) generate an enhanced end effect force with the same amplitude and opposite phase as the cogging effect force harmonic, which cancels out the magnetic resistance caused by the cogging effect of the combined primary as a whole.

2. The combined permanent magnet synchronous linear motor with end permanent magnet assistance according to claim 1, characterized in that: The number of the end permanent magnets (42) embedded in each end core (41) is one or more; the end core (41) is a rectangular block, and the end permanent magnets (42) are rectangular strips or arc-shaped strips.

3. The combined permanent magnet synchronous linear motor with end permanent magnet assistance according to claim 2, characterized in that: The end core (41) is solid or has one or more cavities (43) that run through it in the front-back direction.

4. The combined permanent magnet synchronous linear motor with end permanent magnet assistance according to claim 2, characterized in that: Each of the end cores (41) has an end permanent magnet (42) attached to or embedded on its lower surface. The magnetization direction of the end permanent magnets (42) on the two end cores (41) is vertical, and the magnetization directions are the same or opposite.

5. The combined permanent magnet synchronous linear motor with end permanent magnet assistance according to claim 2, characterized in that: Each of the two ends of the lower surface of the end core (41) has an end permanent magnet (42) attached to or embedded in it. The magnetization direction of the two end permanent magnets (42) in the same end core (41) is vertical, and the magnetization directions are the same or opposite.

6. The combined permanent magnet synchronous linear motor with end permanent magnet assistance according to claim 3, characterized in that: The cavity (43) is composed of one or more unit cavities; the shape and position of the cavity (43) are obtained through finite element simulation analysis.

7. The combined permanent magnet synchronous linear motor with end permanent magnet assistance according to claim 3, characterized in that: The cavity (43) is located at one or more of the left side, right side, and lower surface of the end core (41), such that the surface of the end core (41) with the cavity (43) is recessed inward.

8. The combined permanent magnet synchronous linear motor with end permanent magnet assistance according to claim 1, characterized in that: The design steps for the end magnetic adjustment block (4) are as follows: S1. Using the single-variable scanning method, the influence of the change of the end core (41) structural parameters on the end effect force is analyzed, and the maximum range of the end effect force adjusted by the key structural parameters of the end core (41) is determined. Based on the characteristic that the combined permanent magnet synchronous linear motor has only two ends, the cogging effect force of the combined permanent magnet synchronous linear motor with different numbers is analyzed by finite element simulation. If the cogging effect force exceeds the maximum end effect force, it indicates that the end magnet adjustment block (4) with end permanent magnet assistance needs to be used. S2. Add end permanent magnets (42) to the finite element simulation model. Similarly, perform parametric scanning through finite element simulation to determine the size, quantity, and position of the end permanent magnets (42) that satisfy the condition that the amplitude of the end effect force after adding permanent magnets is equal to the amplitude of the cogging effect force of the combined linear motor.

9. The combined permanent magnet synchronous linear motor with end permanent magnet assistance according to claim 8, characterized in that: The design steps of the end magnetic adjustment block (4) include: The magnetic reluctance of a combined permanent magnet synchronous linear motor can be quickly solved using a finite element simulation model. Based on the cogging force amplitude, the height, width, and position of the end permanent magnet (42) are determined using a single-parameter scanning method. Different digital matrices are used to characterize the material composition and shape of the end magnetizing block (4). The thrust and thrust fluctuation under different end magnetizing block (4) shapes are used as optimization targets. The genetic algorithm is used to quickly find the optimal shape and the optimal shape is selected based on the obtained Pareto front diagram.

Images