Secondary segmented modular bilateral magnetic flux switching linear motor

Abstract

The invention relates to a secondary segmented modular bilateral magnetic flux switching linear motor which comprises a primary rotor and secondary stators located on the two sides of the primary rotor, the length of the secondary stators is far larger than that of the primary rotor, an air gap exists between the primary rotor and the secondary stators, the secondary stators are fixed components, the primary rotor is a moving component, and the secondary stators are fixed components. The primary rotor does linear motion between the secondary stators on the two sides to form the motor of a flat plate structure, the primary rotor comprises six three-phase modules, each three-phase module comprises two side-by-side sub-modules, every two adjacent sub-modules are separated through a magnetic barrier, each sub-module comprises a permanent magnet and magnetic conductive iron cores located on the two sides of the permanent magnet, and the magnetic conductive iron cores are arranged on the two sides of the permanent magnet. The permanent magnet and the two magnetic conductive iron cores form an H-shaped structure, a gap between the two magnetic conductive iron cores in each sub-module is a winding mounting groove, armature windings are wound on the two sides of each three-phase module respectively, and the armature windings are located in the winding mounting grooves of the two sub-modules. According to the invention, stable thrust with extremely low fluctuation can be generated.

Description

Technical Field

[0001] The invention relates to a linear motor, in particular to a secondary segmented modular bilateral magnetic flux switching linear motor. Background Art

[0002] Traditional rotary motors are difficult to meet the needs of many application scenarios due to their reliance on transmission systems. Linear motors do not require transmission mechanisms and have good starting, acceleration and braking performance, showing unique advantages in the traction field. The new type of magnetic field modulation motor, the flux switching linear motor, has the advantages of high efficiency and high thrust density, and has broad application prospects in many fields such as precision lathes, urban smart elevators, and rail transit. Since unilateral permanent magnet linear motors have the universal problem of high normal force, bilateral linear motors have emerged to solve this problem.

[0003] However, the existing bilateral flux switching linear motors still have the problem of high thrust fluctuation, or low thrust fluctuation but low thrust density, which limits the improvement of their electromagnetic performance and practical applications. Summary of the invention

[0004] The purpose of the present invention is to provide a secondary segmented modular bilateral flux switching linear motor to solve the problem of high thrust fluctuation of existing linear motors.

[0005] The present invention is implemented as follows: a secondary segmented modular bilateral flux switching linear motor, including a primary mover and a secondary stator located on both sides of the primary mover, the length of the secondary stator is much greater than the length of the primary mover, there is an air gap between the primary mover and the secondary stator, the secondary stator is a fixed component, the primary mover is a moving component, the primary mover performs a linear motion between the secondary stators on both sides, forming a motor with a flat structure, the primary mover includes 6 three-phase modules, each three-phase module includes two side-by-side sub-modules, two adjacent sub-modules are separated by a magnetic barrier, and the sub-module includes a permanent magnet and a magnetic core located on both sides of the permanent magnet, the permanent magnet and the two magnetic cores form an H-shaped structure, the gap between the two magnetic cores in each submodule is a winding installation slot, and the armature winding is wound on both sides of each three-phase module, and the armature winding is located in the winding installation slots of the two submodules; the 6 three-phase modules of the primary mover are divided into a left ABC module and a right ABC module, and the left ABC module and the right ABC module both include a phase A module, a phase B module, and a phase C module arranged in sequence, a total of 3 three-phase modules; the secondary stator is composed of segmented magnetic strips, and the distance between the center lines of two adjacent magnetic strips is the secondary pitch τ s .

[0006] Furthermore, the centerline spacing between adjacent A-phase modules and B-phase modules and the centerline spacing between adjacent B-phase modules and C-phase modules is (n±1 / 3)τs or (n±1 / 6)τ s , n is any integer.

[0007] Furthermore, the distance between the center line of the C phase module in the left ABC module and the center line of the A phase module in the right ABC module is (n±1 / 3±1 / 12)τ s or (n±1 / 6±1 / 12)τ s , n is any integer.

[0008] Furthermore, the magnetization direction of the permanent magnet is parallel to the running direction of the primary mover, and the polarities of the permanent magnets carried by two submodules belonging to the same three-phase module are arranged in the same direction.

[0009] Furthermore, there are three schemes for arranging the directions of the permanent magnet poles between the three-phase modules. The direction of movement of the permanent magnet N pole is denoted as N, the direction of movement of the permanent magnet S pole is denoted as S, and the permanent magnet poles of adjacent three-phase modules are arranged in opposite directions, i.e., NSN-SNS or SNS-NSN.

[0010] Furthermore, the two secondary stators are staggered from each other by 1 / 2 of the secondary pole pitch τ in the running direction of the primary mover. s .

[0011] Furthermore, the middle portion of the magnetically conductive core protrudes to one side to form a convex structure, and the permanent magnet is located between the protruding portions of the two magnetically conductive cores.

[0012] Furthermore, the magnetic conductive strip is a trapezoidal structure, with the long bottom side located inside and the short bottom side located outside.

[0013] Furthermore, two armature windings carried by two submodules belonging to the same three-phase module adopt the same winding direction.

[0014] Furthermore, the armature winding is powered according to the three-phase module in which it is located, using I d =0 three-phase power supply mode, I d is the d-axis component of the input current.

[0015] The motor of the present invention adopts a primary modular structure, and the modular structure of the primary mover is beneficial to suppressing the end effect, reducing the mutual influence between modules, and improving the safety of motor operation. The secondary stator adopts a segmented structure, the magnetic circuit is simpler, the implementation process of the flux switching principle is good, and the segmented secondary occupies a smaller area than the continuous secondary. The secondary stators on both sides are misaligned by half the secondary pole pitch in the running direction of the primary mover, which can enhance the air gap magnetic field, improve the utilization rate of the permanent magnet, and weaken the effect of thrust fluctuation. Through the above-mentioned two secondary misalignments and segmented secondary, the cooperation of the primary and secondary of the present invention adopts a new way to realize the flux switching principle, and the implementation method of the flux switching principle is simple and efficient.

[0016] In addition, the protrusion of the primary permeable core structure of the present invention can adjust the width of the permanent magnet by adjusting the width of the protrusion without affecting the position and size of other structures, making the adjustment of the permanent magnet material more flexible and achieving an optimal value between the thrust mean, thrust fluctuation, and the cost of the permanent magnet material. The main harmonic component of the positioning force of a single ABC module of the present invention is the sixth harmonic. In view of this feature, a twelfth of the secondary pole pitch τ is added between the two ABC modules. s The misalignment effectively cancels out the six-order components of the positioning force, reducing the positioning force, thereby greatly reducing thrust fluctuations and achieving low thrust fluctuations. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the secondary segmented modular bilateral flux switching linear motor of the present invention.

[0018] Figure 2 It is a schematic diagram of the primary three-phase module unit of the secondary segmented modular bilateral flux switching linear motor of the present invention.

[0019] Figure 3 This is a schematic diagram of the operating principle of the secondary segmented modular bilateral flux switching linear motor of the present invention. When the secondary moves, the position relationship between the secondary and the primary is Figure 3 (a) and Figure 3 (b) Switch between.

[0020] Figure 4 It is a schematic diagram of the alternating magnetization of the permanent magnets of the secondary segmented modular bilateral flux switching linear motor of the present invention.

[0021] Figure 5 It is a positioning force curve diagram of a single ABC module and the entire motor (including two ABC modules, and the distance between the two ABC modules is not adjusted) of the present invention.

[0022] Figure 6 yes Figure 5 Harmonic component analysis diagram of positioning force.

[0023] Figure 7 It is a comparison diagram of the motor thrust before and after the structural optimization of the secondary segmented modular bilateral flux switching linear motor of the present invention.

[0024] In the figure: 1. primary mover; 2. secondary stator; 3. air gap; 4. ABC module; 5. A phase module; 6. B phase module; 7. C phase module; 8. sub-module; 9. magnetic barrier; 10. permanent magnet; 11. magnetic core; 12. winding mounting slot; 13. armature winding; 14. magnetic strip; 15. magnetic circuit. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] like Figure 1 , Figure 2 As shown, a secondary segmented modular bilateral flux switching linear motor of the present invention comprises a primary mover 1 and two secondary stators 2 located on both sides of the primary mover 1. The length of the secondary stator 2 is much greater than the length of the primary mover 1. There is an air gap 3 between the primary mover 1 and the secondary stator 2. The widths of the two air gaps 3 are equal. Among them, the secondary stator 2 is a fixed component, the primary mover 1 is a moving component, and the primary mover 1 performs linear motion between the secondary stators 2 on both sides, forming a motor with a flat structure.

[0027] Among them, a primary mover 1 includes 6 three-phase modules, each of which includes two side-by-side sub-modules 8, and two adjacent sub-modules 8 are separated by a magnetic barrier 9. Each sub-module 8 includes a permanent magnet 10 and a magnetically conductive core 11 located on both sides of the permanent magnet 10, and the permanent magnet 10 is sandwiched between the two magnetically conductive cores 11, and the permanent magnet 10 and the two magnetically conductive cores 11 form an H-shaped structure. In each sub-module 8, the gap between the two magnetically conductive cores 11 forms a winding installation groove 12, and there is a winding installation groove 12 on both sides of the sub-module 8. The armature winding 13 is wound on both sides of each three-phase module, and the armature winding 13 is located in the winding installation grooves 12 of the two sub-modules 8.

[0028] The middle part of the permeable core 11 protrudes to one side to form a convex structure, and the permanent magnet 10 is located between the protruding parts of the two permeable cores 11. Figure 1 , Figure 2 In the up and down direction, the length of the permanent magnet 10 is consistent with the length of the protruding portion.

[0029] The protrusions on the permeable core 11 can adjust the width of the permanent magnet 10 without affecting the fit between the primary mover 1 and the secondary stator 2, so that the material of the permanent magnet 10 takes into account both the thrust mean and thrust fluctuation, and reduces a certain cost. The unique arrangement of the permanent magnet 10 in the primary mover 1 is conducive to achieving a good magnetic field concentration effect, and obtains a lower positioning force level while increasing the no-load back electromotive force. The size of the no-load back electromotive force determines its thrust size, and the positioning force is the main influencing factor of the thrust fluctuation.

[0030] The two armature windings 13 carried by the two submodules 8 belonging to the same three-phase module have the same winding direction.

[0031] like Figure 2 As shown, the six three-phase modules of the primary mover 1 are divided into a left ABC module 4 and a right ABC module 4, and both the left ABC module 4 and the right ABC module 4 include three three-phase modules, namely, an A-phase module 5, a B-phase module 6, and a C-phase module 7, which are arranged in sequence. Therefore, the six three-phase modules of the primary mover 1 are, from left to right, an A-phase module 5, a B-phase module 6, a C-phase module 7, an A-phase module 5, a B-phase module 6, and a C-phase module 7.

[0032] The secondary stator 2 is composed of segmented magnetic strips 14, and the distance between the center lines of two adjacent magnetic strips 14 is the secondary pitch τ s .

[0033] The magnetic conductive strip 14 is a trapezoidal structure, with the long bottom side located inside and the short bottom side located outside.

[0034] The two secondary stators 2 are staggered by 1 / 2 of the secondary pole pitch τ in the running direction of the primary mover 1. s Since the two secondary stators 2 are offset by half of the secondary pole pitch, the magnetic field of the air gap 3 can be enhanced, the utilization rate of the permanent magnet 10 can be improved, and the thrust fluctuation can be weakened.

[0035] The centerline spacing between adjacent A-phase modules 5 and B-phase modules 6 and the centerline spacing between adjacent B-phase modules 6 and C-phase modules 7 is (n±1 / 3)τ s or (n±1 / 6)τ s , n is an arbitrary integer. This ensures that there is a secondary step distance τ of 1 / 3 or 1 / 6 between adjacent three-phase modules. s phase difference to facilitate the generation of no-load back electromotive force corresponding to the three-phase current.

[0036] like Figure 5 , Figure 6As shown in FIG. 1 , before the spacing between the left ABC module 4 and the right ABC module 4 is adjusted, the main harmonic orders of the positioning force of a single module and the entire motor (including two single ABC modules) are 2nd and 6th, among which the 6th order component has a relatively obvious superposition relationship, and the amplitude of the 2nd order component is basically the same. Figure 6 It can be seen that the main harmonic components of the positioning force are even harmonics. This is because there are two working air gaps 3 in the double-sided motor. The secondary staggered design of T / 2 of the present invention effectively offsets the main odd harmonic components.

[0037] The thrust fluctuation is mainly caused by the positioning force. In order to further reduce the positioning force and thus reduce the thrust fluctuation, the distance between the two ABC modules 4 is appropriately reduced to increase the magnetic focusing effect of the two ABC modules 4, thereby offsetting the positioning force caused by the magnetic focusing effect.

[0038] Specifically, the left ABC module 4 is shifted right by τs / 24, and the right ABC module 4 is shifted left by τ s / 24, the initial phase of the supply current remains unchanged. In this way, the electrical phase between the left and right parts is separated by τ s / 12, that is, the positioning forces generated by the left ABC module 4 and the right ABC module 4 are misaligned by T / 12, T is the period of the positioning force fluctuation, and there is an obvious mutual cancellation phenomenon between the positioning forces of the left ABC module 4 and the right ABC module 4, thereby reducing the positioning force of the motor. Finally, the center line spacing between the C phase module 7 in the left ABC module 4 and the A phase module 5 in the right ABC module 4 is (n±1 / 3±1 / 12)τ s or (n±1 / 6±1 / 12)τ s , n is an arbitrary integer. Through this adjustment, the 6th order components of the positioning force are effectively offset each other, and the magnetic aggregation effect of the two ABC modules 4 is increased, thereby offsetting the positioning force caused by the magnetic aggregation effect, thereby reducing the 2nd order positioning force, such as Figure 7 As shown in the figure, the average thrust is slightly reduced compared with before optimization, but the thrust fluctuation is significantly reduced.

[0039] In each submodule 8 , the magnetization direction of the permanent magnet 10 is parallel to the running direction of the primary mover 1 , and the polarities of the permanent magnets 10 carried by two submodules 8 belonging to the same three-phase module are arranged in the same direction.

[0040] Specifically, the direction of movement of the permanent magnet's N pole is denoted as N, and the direction of movement of the permanent magnet's S pole is denoted as S. An alternating magnetization method is adopted in which the permanent magnet poles of adjacent three-phase modules are arranged in opposite directions, i.e., NSN-SNS or SNS-NSN. Figure 4 As shown, the arrow direction indicates the magnetization direction of the permanent magnet 10.

[0041] The permanent magnet pole orientation may also be arranged in other ways, but in the present invention, alternating magnetization and reducing the distance between the two ABC modules are used to better reduce thrust fluctuations.

[0042] The linear motor proposed in the present invention operates based on the principle of minimum magnetic resistance. The working principle of a single three-phase module is as follows: Figure 3 As shown, when in Figure 3 (a) position, the left permanent magnet 10 and the lower trapezoidal magnetic strip 14 generate a closed magnetic circuit 15 with minimum magnetic resistance, and the right permanent magnet 10 and the upper trapezoidal magnetic strip 14 form a closed magnetic circuit 15. At this time, the positive magnetic flux of the armature winding 13 is the largest. Figure 3 (b) When the left permanent magnet 10 and the upper trapezoidal magnetic strip 14 form a closed magnetic circuit 15, the right permanent magnet 10 and the lower trapezoidal magnetic strip 14 form a closed magnetic circuit 15. At this time, the reverse magnetic flux of the armature winding 13 is the largest. It can be seen that with the movement of the secondary mover, the position relationship between the secondary stator 2 and the primary mover 1 is Figure 3 (a) with Figure 3 (b) switching between the two, an alternating magnetic circuit 15 can be formed in the armature winding 13, thereby generating a back electromotive force in the winding. Figure 3 (a) Location and Figure 3 (b) It is zero at position 2 and reaches a peak at its midpoint.

[0043] The armature winding 13 is powered according to the three-phase module in which it is located. d =0 three-phase power supply mode, I d is the d-axis component of the input current. During the control process, the d-axis component of the stator current I d is zero.

[0044] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments may still be modified, or some or all of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A secondary segmented modular bilateral flux switching linear motor, comprising a primary mover and secondary stators located on both sides of the primary mover, wherein the length of the secondary stator is much greater than the length of the primary mover, an air gap exists between the primary mover and the secondary stator, the secondary stator is a fixed component, the primary mover is a moving component, the primary mover performs linear motion between the secondary stators on both sides, and constitutes a motor with a flat structure, characterized in that: The primary mover includes 6 three-phase modules, each of which includes two side-by-side sub-modules, and two adjacent sub-modules are separated by a magnetic barrier. The sub-module includes a permanent magnet and a magnetic core located on both sides of the permanent magnet. The permanent magnet and the two magnetic cores form an H-shaped structure. The gap between the two magnetic cores in each sub-module is a winding installation groove. The armature windings are wound on both sides of each three-phase module, and the armature windings are located in the winding installation grooves of the two sub-modules; the 6 three-phase modules of the primary mover are divided into a left ABC module and a right ABC module. The left ABC module and the right ABC module both include a total of 3 three-phase modules, namely, an A-phase module, a B-phase module, and a C-phase module arranged in sequence; the secondary stator is composed of segmented magnetic strips, and the distance between the center lines of two adjacent magnetic strips is the secondary pitch τ s .

2. The secondary segmented modular bilateral flux switching linear motor according to claim 1, characterized in that: The centerline spacing between adjacent A-phase modules and B-phase modules and the centerline spacing between adjacent B-phase modules and C-phase modules is (n±1 / 3)τ s or (n±1 / 6)τ s , n is any integer.

3. The secondary segmented modular bilateral flux switching linear motor according to claim 2, characterized in that: The distance between the center line of the C phase module in the left ABC module and the center line of the A phase module in the right ABC module is (n±1 / 3±1 / 12)τ s or (n±1 / 6±1 / 12)τ s , n is any integer.

4. The secondary segmented modular bilateral flux switching linear motor according to claim 1, characterized in that: The magnetization direction of the permanent magnet is parallel to the running direction of the primary mover, and the polarities of the permanent magnets carried by two submodules belonging to the same three-phase module are arranged in the same direction.

5. The secondary segmented modular bilateral flux switching linear motor according to claim 4, characterized in that: The direction of movement of the permanent magnet's N pole is denoted as N, and the direction of movement of the permanent magnet's S pole is denoted as S. The permanent magnet poles of adjacent three-phase modules are arranged in opposite directions, i.e., NSN-SNS or SNS-NSN.

6. The secondary segmented modular bilateral flux switching linear motor according to claim 1, characterized in that: The two secondary stators are staggered by 1 / 2 of the secondary pole pitch τ in the running direction of the primary mover. s .

7. The secondary segmented modular bilateral flux switching linear motor according to claim 1, characterized in that: The middle part of the magnetic conductive core protrudes to one side to form a convex structure, and the permanent magnet is located between the protruding parts of the two magnetic conductive cores.

8. The secondary segmented modular bilateral flux switching linear motor according to claim 1, characterized in that: The magnetic conductive strip is a trapezoidal structure, with the long bottom side located inside and the short bottom side located outside.

9. The secondary segmented modular bilateral flux switching linear motor according to claim 1, characterized in that: The two armature windings carried by the two submodules belonging to the same three-phase module adopt the same winding direction.

10. The secondary segmented modular bilateral flux switching linear motor according to claim 1, characterized in that: The armature winding is powered according to the three-phase module in which it is located. d =0 three-phase power supply mode, I d is the d-axis component of the input current.

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