A strong magnetic field-concentrating double-sided excitation magnetic field modulation permanent magnet cutting motor for coal mine excavation robots

Abstract

The present invention belongs to the technical field of coal mine excavation robots, and discloses a strong magnetic field concentration type double-sided excitation magnetic field modulation permanent magnet cutting motor for coal mine excavation robots. The motor adopts an outer stator and inner rotor structure, and permanent magnets are arranged on both the stator side and the rotor side, thereby forming a bidirectional magnetic field modulation effect, generating a large number of air gap magnetic field harmonics, and thus greatly improving the torque density. In addition, the permanent magnets on the stator side form a Halbach array arrangement and a double-spoke array arrangement. While the permanent magnets arranged in the Halbach array have a magnetic field concentration effect, the two side permanent magnets of the Halbach array are respectively connected to the stator permanent magnets at the side positions corresponding to the inner ends of the stator teeth to form a spoke array arrangement of permanent magnets, thereby introducing another two magnetic field concentration effects. This new strong magnetic field concentration type permanent magnet arrangement method can greatly improve the magnetomotive force of the permanent magnets on the stator side and improve the torque density. At the same time, the stator permanent magnets at the inner end edge positions of the stator teeth also have a pole-changing effect, thereby increasing the torque density.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mine excavation robots, and in particular relates to a strong magnetic concentration type double-sided excitation magnetic field modulation permanent magnet cutting motor for coal mine excavation robots. Background Art

[0002] Coal mine excavation robots are specialized industrial robots capable of autonomously completing excavation operations in harsh mine environments. They are crucial for achieving unmanned, intelligent, and safer excavation work faces. The cutting unit is the core actuator for coal mine excavation robots and also the most energy-intensive component of the entire machine. Its transmission system currently utilizes an "asynchronous motor + gear mechanism + cutting drum" structure. However, this transmission system suffers from long transmission lines, low efficiency, and poor reliability. Therefore, achieving a direct-drive transmission system for coal mine excavation robots is imperative.

[0003] Coal mining robots require high cutting torque, but the cutting unit space is limited. Therefore, direct-drive cutting motors have very demanding requirements for torque density. However, traditional low-speed, high-torque permanent magnet direct-drive motors are limited by the number of pole pairs between the permanent magnets and the armature windings, resulting in bulky design and insufficient torque density. Therefore, improving the torque density of cutting motors in coal mining robots has become a research hotspot and a pressing issue in the field of coal mining robot technology. Summary of the Invention

[0004] In response to the above technical problems existing in the prior art, the present invention proposes a strong magnetic field-concentrating double-sided excitation magnetic field modulation permanent magnet cutting motor for a coal mine tunneling robot, so as to greatly improve the torque density of the cutting motor.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0006] A strong magnetic field-concentrated double-sided excitation magnetic field modulation permanent magnet cutting motor for a coal mine excavation robot comprises a stator, a rotor and an armature winding. The stator is located outside the rotor, and an air gap is left between the stator and the rotor.

[0007] The stator includes a stator yoke and stator teeth; wherein the stator yoke is annular; there are multiple stator teeth, and each stator tooth is arranged in sequence in the inner circumferential direction of the stator yoke;

[0008] Five stator permanent magnets are provided at the inner end of each stator tooth;

[0009] The five stator permanent magnets are arranged in sequence along the tangential direction, wherein three stator permanent magnets are located in the middle of the inner end, and the remaining two stator permanent magnets are located at an edge position of the inner end respectively;

[0010] three stator permanent magnets located at the middle of the inner end, including a middle permanent magnet and two side permanent magnets, wherein the two side permanent magnets are located on opposite sides of the middle permanent magnet in the tangential direction;

[0011] Each side permanent magnet is separated from the stator permanent magnet at an edge position on the corresponding side by an iron pole;

[0012] The three stator permanent magnets located in the middle of the inner end form a Halbach array arrangement; each side permanent magnet of the Halbach array, the iron pole on the corresponding side, and the stator permanent magnet at the edge position on the corresponding side form a spoke array arrangement;

[0013] The magnetization direction of the central permanent magnet of the Halbach array is radially outward; the magnetization direction of a side permanent magnet and a stator permanent magnet at an edge position in the same spoke array are both tangential, and the magnetization directions of the two are opposite;

[0014] A plurality of rotor permanent magnets are arranged on the rotor along its circumferential direction; and the armature winding is wound on the stator teeth.

[0015] In addition, the present invention also provides a coal mine excavation robot, which includes a cutting part. The cutting motor in the cutting part adopts the strong magnetic concentration type double-sided excitation magnetic field modulation permanent magnet cutting motor for coal mine excavation robots as described above.

[0016] The present invention has the following advantages:

[0017] As described above, the present invention relates to a strong magnetic focusing type bilateral excitation magnetic field modulation permanent magnet cutting motor for a coal mine excavation robot. The motor adopts an outer stator and inner rotor structure. Permanent magnets are arranged on both the stator side and the rotor side, wherein the magnetic field of the permanent magnet on the stator side is modulated by the rotor teeth, and the magnetic field of the permanent magnet on the rotor side is modulated by the stator teeth, thereby forming a bidirectional magnetic field modulation effect, generating a large number of air gap magnetic field harmonics, and thus greatly improving the torque density. The present invention produces a strong magnetic focusing effect through the special arrangement of the permanent magnets on the stator side, thereby greatly improving the magnetomotive force of the permanent magnet on the stator side. Specifically, five stator permanent magnets are arranged at the inner end of each stator tooth; the five stator permanent magnets are arranged in sequence along the tangential direction, of which three stator permanent magnets are located in the middle position of the inner end, and the remaining two stator permanent magnets are respectively located at an edge position of the inner end. The three stator permanent magnets located in the middle of the inner end form a Halbach array arrangement; at the same time, each side permanent magnet of the Halbach array forms a spoke array arrangement with the permanent magnets at the side positions corresponding to the inner end of the stator teeth, thereby introducing another two-fold magnetic focusing effect, wherein the permanent magnets arranged in the Halbach array in the middle of the stator teeth and the double-spoke array at the edge of the stator teeth both have magnetic focusing effects. This new type of strong magnetic focusing permanent magnet arrangement can greatly improve the air gap magnetic density of the motor, thereby improving the torque density. In addition, the stator permanent magnets arranged at the edge positions of the inner end of the stator teeth in the present invention also have a pole-changing effect, that is, when there are no stator permanent magnets at the edge positions, the pole pair number of the stator side permanent magnets is Z. s Pole pairs: When the stator permanent magnets are placed at the edge, the number of stator permanent magnet pole pairs becomes 2Z s Pole pairs. For magnetic field modulation motors, after the number of permanent magnet pole pairs on the stator side increases, the low-order harmonic components of the air gap magnetic field generated by the rotor side modulation increase, so that the number of armature winding pole pairs is lower and the pole ratio increases. The torque is proportional to the pole ratio. Therefore, the pole-changing effect of the stator permanent magnets at the inner end edge of the stator teeth can effectively increase the pole ratio, thereby further improving the torque density. In addition, the rotor structure of the motor in the present invention adopts an alternating pole permanent magnet arrangement, so it has a simple structure, high mechanical strength, and a low risk of permanent magnet demagnetization, which is particularly suitable for tunneling occasions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a cross-sectional view of a strong magnetic field-concentrating double-sided excitation magnetic field modulation permanent magnet cutting motor for a coal mine excavation robot in an embodiment of the present invention, wherein the direction of the arrow in the figure indicates the magnetization direction of the permanent magnet.

[0019] Figure 2 for Figure 1 Enlarged view of part A in .

[0020] Figure 3This is a no-load magnetic field line distribution diagram of a strong magnetic focusing double-sided excitation magnetic field modulation permanent magnet cutting motor used in a coal mine excavation robot in an embodiment of the present invention.

[0021] Figure 4 2 is a comparison diagram of the magnetomotive force distribution of the motor under different stator-side permanent magnet excitations in an embodiment of the present invention.

[0022] Figure 5 1 is a comparison diagram of the Fourier harmonic analysis of the magnetomotive force of the motor under different stator-side permanent magnet excitations in an embodiment of the present invention.

[0023] Figure 6 1 is a comparison diagram of the air gap flux density distribution of the motor under different stator side permanent magnet excitations in an embodiment of the present invention.

[0024] Figure 7 1 is a comparison diagram of the Fourier harmonic analysis of the air gap flux density of the motor under different stator-side permanent magnet excitations in an embodiment of the present invention.

[0025] Figure 8 1 is a comparison diagram of the air gap flux density distribution of the motor under different permanent magnet excitations in an embodiment of the present invention.

[0026] Figure 9 1 is a comparison diagram of the air gap flux Fourier harmonic analysis of the motor under different permanent magnet excitations in an embodiment of the present invention.

[0027] Figure 10 2 is a comparison diagram of the reverse electromotive force waveforms of the motor under different permanent magnet excitations in an embodiment of the present invention.

[0028] Figure 11 1 is a comparison diagram of the Fourier harmonic analysis of the opposite electromotive force of the motor under different permanent magnet excitations in an embodiment of the present invention.

[0029] Figure 12 2 is a comparison diagram of the torque waveforms generated by the motor under different permanent magnet excitations in an embodiment of the present invention.

[0030] Figure 13 This is a comparison chart of the proportion of the air gap flux harmonic contribution to torque of the motor of each order under different permanent magnet excitations in an embodiment of the present invention.

[0031] Among them, 1-stator, 2-rotor, 3-armature winding, 4-rotor permanent magnet, 5-stator yoke, 6-stator teeth, 7-stator permanent magnet, 8-middle permanent magnet, 9-side permanent magnet, 10-edge permanent magnet, 11-iron pole. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0033] Example 1

[0034] like Figure 1 As shown, this embodiment 1 describes a strong magnetic field concentrated double-sided excitation magnetic field modulation permanent magnet cutting motor for a coal mine excavation robot, which includes a stator 1, a rotor 2 and an armature winding 3.

[0035] The stator 1 is located outside the rotor 2, with an air gap between the stator 1 and the rotor 2. The length of the air gap is related to the power level of the motor, the selected permanent magnet material, and the processing and assembly process of the stator 1 and the rotor 2.

[0036] The cores of the stator 1 and the rotor 2 are both made of laminated silicon steel sheets.

[0037] Among them, the thickness of the silicon steel sheet is usually selected between 0.35mm and 0.5mm, and the stacking coefficient is 0.95.

[0038] The stator 1 includes a stator yoke 5 and stator teeth 6 ; the stator yoke 5 is annular; there are a plurality of stator teeth 6 , and each stator tooth 6 is sequentially arranged in the inner circumferential direction of the stator yoke 5 .

[0039] The outer ends of the stator teeth 6 are connected to the inner side of the stator yoke 5 , and the inner ends thereof extend to the outer side of the rotor 2 .

[0040] Five stator permanent magnets 7 are provided at the inner end of each stator tooth 6 .

[0041] The five stator permanent magnets 7 are arranged in sequence along the tangential direction, wherein three stator permanent magnets 7 are located at the middle position O of the inner end, and the remaining two stator permanent magnets 7 are located at an edge position A and B of the inner end, respectively. Figure 2 shown.

[0042] The tangential direction here refers to the direction perpendicular to the radial direction described below. The radial direction refers to the direction pointing outward along the radial direction from the center of the motor, and the direction perpendicular to the radial direction is defined as the tangential direction.

[0043] Permanent magnet materials can be selected based on motor performance requirements, operating temperature, and cost. For example, NdFeB or ferrite magnets can be used. Permanent magnets can be made of the same material or different materials, creating a hybrid permanent magnet configuration.

[0044] The three stator permanent magnets located in the middle of the inner end include a middle permanent magnet 8 and two side permanent magnets 9. The two side permanent magnets 9 are located on the opposite sides of the middle permanent magnet 8 along the tangential direction (i.e. Figure 2 left and right sides of the display).

[0045] Among them, the edge position A is Figure 2 The left side position, side position B is Figure 2 Middle right side position.

[0046] Each side permanent magnet 9 is separated from a stator permanent magnet at a side position on the corresponding side by an iron pole 11. For the convenience of description, the stator permanent magnet at the side position is defined as a side permanent magnet 10.

[0047] Specifically, the left side permanent magnet 9 is separated from the side permanent magnet 10 at the side position A by an iron pole 11. Similarly, the right side permanent magnet 9 is separated from the side permanent magnet 10 at the side position B by an iron pole 11.

[0048] The three stator permanent magnets located at the middle position O of the inner end form a Halbach array arrangement. Each side permanent magnet 9 of the Halbach array forms a spoke array arrangement with the iron pole 11 and the edge permanent magnet 10 on the corresponding side.

[0049] Specifically, the left side permanent magnet 9 , the iron pole 11 (between the left side permanent magnet 9 and the side permanent magnet 10 at the side position A), and the side permanent magnet 10 at the side position A form a spoke array arrangement.

[0050] Similarly, the right side permanent magnet 9, the iron pole 11 (between the right side permanent magnet 9 and the side permanent magnet 10 at the side position B), and the side permanent magnet 10 at the side position B form a spoke array arrangement.

[0051] The magnetization direction of the middle permanent magnet 8 of the Halbach array is radially outward.

[0052] The magnetization directions of a side permanent magnet 9 and a stator permanent magnet at an edge position (i.e., the edge permanent magnet 10) in the same spoke array are both along the tangential direction, and the magnetization directions of the two are opposite, such as Figure 2 shown.

[0053] While the permanent magnets arranged in the Halbach array have a magnetic focusing effect, each side permanent magnet 9 of the Halbach array forms a spoke array arrangement of permanent magnets with the edge permanent magnet 10 on the corresponding side, introducing another two magnetic focusing effects. This new strong magnetic focusing permanent magnet arrangement method greatly improves the magnetomotive force of the permanent magnets on the stator side and improves the torque density.

[0054] At the same time, the edge permanent magnets 10 in this embodiment also have a polarity-changing function.

[0055] Specifically, when there is no edge permanent magnet 10, the number of pole pairs of the stator side permanent magnet is Z s After the edge permanent magnet 10 is placed, the number of pole pairs of the stator side permanent magnet becomes 2Z s The magnetomotive force waveform and harmonic distribution generated by the stator side permanent magnet are as follows: Figure 4 、 Figure 5 As shown. It can be seen that the number of stator magnetomotive force pole pairs generated by the permanent magnets arranged in the Halbach array is 6 (that is, Z in this case s =6), and the number of stator magnetomotive force pole pairs generated by the permanent magnets arranged in the spoke array is also 6. When the two groups of array-arranged permanent magnets together form the stator side permanent magnet structure, the number of stator magnetomotive force pole pairs becomes 12.

[0056] For magnetic field modulation motors, when the number of permanent magnet pole pairs on the stator side increases, the low-order harmonic components of the air gap magnetic field generated by the rotor side modulation increase, such as Figure 6 、 Figure 7 As shown. Figure 6 and Figure 7 It can be seen that the number of armature winding pole pairs is lower than that before the pole change. r -Z s |Decrease to|Z r -2Z s |, the pole ratio is Z before the pole change r / |Z r -Z s | Increase to Z r / |Z r -2Z s |, and the torque is proportional to the pole ratio, so the pole-changing effect of the permanent magnet at the inner end of the stator teeth can effectively increase the pole ratio, thereby further improving the torque density, where Z s is the number of permanent magnet teeth, where Z r Indicates the number of rotor pole pairs.

[0057] Rotor 2 is circumferentially equipped with multiple rotor permanent magnets 4, magnetized radially outward. This rotor utilizes an alternating-pole permanent magnet arrangement, resulting in a simple structure, high mechanical strength, and a low risk of permanent magnet demagnetization, making it suitable for tunneling applications.

[0058] Permanent magnets are placed on both the stator and rotor sides of the motor. The magnetic field of the stator permanent magnet is modulated by the rotor teeth, and the magnetic field of the rotor permanent magnet is modulated by the stator teeth, thus forming a bidirectional magnetic field modulation effect and generating a large number of air gap magnetic field harmonics, thereby greatly improving the torque density.

[0059] The armature winding 3 is arranged on the stator teeth 6. In this embodiment, the armature winding 3 adopts a concentrated winding structure, which can effectively reduce the length of the winding end and reduce copper loss, which is beneficial to improving the operating efficiency of the motor.

[0060] The operating principle of the strong magnetic field-concentrating double-sided excitation magnetic field modulation permanent magnet cutting motor used in the coal mine excavation robot in this embodiment can be explained from the perspectives of flux change and magnetic field modulation, as follows:

[0061] From the perspective of magnetic field modulation, since both the motor's stator 1 and rotor 2 are salient pole structures and both are equipped with permanent magnets, the stator 1 and rotor 2 can simultaneously provide permanent magnet excitation magnetic fields and magnetic field modulation functions. By simultaneously utilizing the stator teeth to modulate the magnetic field generated by the rotor permanent magnets 4 on the rotor, and the rotor teeth to modulate the magnetic field generated by the stator permanent magnets 7 on the stator, a "bidirectional magnetic field modulation" effect, the motor can obtain richer and higher-amplitude air gap magnetic field operating harmonics than traditional stator permanent magnet or rotor permanent magnet magnetic field modulation motors, including the 1st harmonic, 5th harmonic, 7th harmonic, 11th harmonic, 25th harmonic, etc., thereby significantly improving the motor's torque density.

[0062] At the same time, the middle permanent magnet 8 and the two side permanent magnets 9 form a Halbach array arrangement. At the same time, each side permanent magnet 9 in the Halbach array arrangement forms a spoke array arrangement with a side permanent magnet 10 on the corresponding side, thereby introducing two more concentrated magnetisms, so that the stator side permanent magnet forms a new type of strong concentrated magnetism structure, and thus has a multiple concentrated magnetism effect, which greatly improves the magnetomotive force of the stator side permanent magnet, thereby improving the torque density. In particular, the pole pair number of the Halbach array arrangement composed of the middle permanent magnet 8 and the two side permanent magnets 9 is Ns, and the pole pair number of the spoke array composed of each side permanent magnet 9 and the corresponding side permanent magnet 10 in the Halbach array arrangement is also Ns. Due to the setting of the magnetization direction, the side permanent magnet 10 has a pole-changing effect on the magnetic field of the Halbach array arrangement, so that the pole pair number of the magnetic field generated by the stator side permanent magnet 7 becomes 2Ns, thereby improving the pole ratio of the magnetic field modulation and further improving the torque density. The motor torque formula can be written as:

[0063]

[0064] Where T avg 、T avgs and T avgr are the total average torque generated by the motor's bilateral permanent magnet excitation, the average torque generated by the stator-side permanent magnet excitation only, and the average torque generated by the rotor-side permanent magnet excitation only; r g 、l st 、N t , I m are the stator air gap radius, the effective length of the core, the number of series turns per phase, and the phase current amplitude respectively; Λ s0 , Λ sn , Λ r1 are the stator permeability harmonic average value, stator permeability nth harmonic amplitude, and rotor fundamental permeability harmonic amplitude respectively; F msi 、F mr1 are the amplitude of the stator magnetomotive force i-th harmonic and the amplitude of the rotor magnetomotive force fundamental wave respectively; k whis the winding coefficient of the hth harmonic.

[0065] It can be seen from the torque formula that the bilateral excitation structure of the present invention can simultaneously generate an average torque T by generating a bidirectional magnetic field modulation effect on the stator side and the rotor side. avgs and T avgr , the torque density is improved. At the same time, the stator side adopts a strong magnetic concentration type permanent magnet arrangement method, which effectively improves the stator magnetomotive force F msi In addition, the pole changing effect produced by the edge permanent magnet 10 increases the pole ratio Z r / |Z r -2Z s |, further improving the torque density.

[0066] Figure 4 This is a comparison diagram of the magnetomotive force distribution of the motor in an embodiment of the present invention under the permanent magnet excitation of the Halbach array arrangement on the stator side only, the permanent magnet excitation of the spoke array arrangement on the stator side, and the total permanent magnet excitation on the stator side. Figure 5 The following is a comparison diagram of the Fourier harmonic analysis of the magnetomotive force of the motor under the permanent magnet excitation of the stator side Halbach array arrangement, the stator side spoke array arrangement and the total permanent magnet excitation of the stator side in the embodiment of the present invention. Figure 4 and Figure 5 It is not difficult to see that the present invention adopts a strong magnetic concentration structure composed of a stator-side Halbach array and a spoke array permanent magnet, and introduces magnetic concentration and pole changing effects at the same time, thereby greatly improving the amplitude of the magnetomotive force, weakening the Zs subharmonic, greatly enhancing the 2Zs subharmonic, and thus improving the torque density.

[0067] Figure 6 This is a comparison diagram of the air gap flux density distribution of the motor under the permanent magnet excitation of the Halbach array arrangement on the stator side only, the permanent magnet excitation of the spoke array arrangement on the stator side, and the total permanent magnet excitation on the stator side in an embodiment of the present invention. Figure 7 The following is a comparison chart of the air gap flux Fourier harmonic analysis of the motor in the embodiment of the present invention under the conditions of permanent magnet excitation of the stator side Halbach array arrangement, permanent magnet excitation of the stator side spoke array arrangement and total permanent magnet excitation of the stator side. Figure 6 and Figure 7 It can be seen that the present invention adopts a strong magnetic concentration structure composed of a Halbach array on the stator side and a spoke array permanent magnet. Through the pole-changing effect of the spoke array permanent magnet and the modulation effect of the rotor teeth on the magnetomotive force on the stator side, the low-order air gap magnetic flux amplitude is greatly improved, thereby improving the torque density.

[0068] like Figure 8Figure 9 shows a comparison of the air gap flux density distribution of the motor under the conditions of only stator side permanent magnet excitation, only rotor side permanent magnet excitation, and bilateral permanent magnet excitation in the embodiment of the present invention. Figure 9 shows a comparison of the air gap flux density distribution of the motor under the conditions of only stator side permanent magnet excitation, only rotor side permanent magnet excitation, and bilateral permanent magnet excitation in the embodiment of the present invention. Figure 8 and Figure 9 It is not difficult to see that the present invention adopts simultaneous excitation of the stator and rotor sides (bilateral permanent magnet), introduces a bidirectional magnetic field modulation effect, greatly improves the air gap magnetic density amplitude, enriches the air gap magnetic density working harmonics, and thus improves the motor torque density.

[0069] like Figure 10 The figure shows the contrasting waveforms of the reverse electromotive force of the motor under the conditions of the permanent magnet excitation of the stator side Halbach array arrangement, the permanent magnet excitation of the stator side spoke array arrangement, the permanent magnet excitation of the rotor side only and the permanent magnet excitation of both sides in the embodiment of the present invention. Figure 11 The following is a comparison of the reverse electromotive force Fourier harmonic analysis of the motor in the embodiment of the present invention under the conditions of permanent magnet excitation of the stator side Halbach array arrangement, permanent magnet excitation of the stator side spoke array arrangement, permanent magnet excitation of the rotor side only, and permanent magnet excitation of both sides. Figure 10 and Figure 11 It can be seen that the stator side of the present invention uses Halbach array and spoke array to produce multiple magnetic field concentration effects, and at the same time, permanent magnets are placed on both the stator and rotor sides to generate bidirectional magnetic field modulation effects, thereby effectively improving the opposite electromotive force.

[0070] Figure 12 A comparison diagram of the torque waveforms generated by the motor in an embodiment of the present invention under the conditions of permanent magnet excitation with Halbach array arrangement on the stator side only, permanent magnet excitation with spoke array arrangement on the stator side, permanent magnet excitation on the rotor side only, and permanent magnet excitation on both sides is shown. Figure 13 The figure shows the proportion of the air gap flux harmonic contribution to torque of the motor in each order under the conditions of permanent magnet excitation of the stator side Halbach array arrangement, permanent magnet excitation of the stator side spoke array arrangement, permanent magnet excitation of the rotor side only and permanent magnet excitation of both sides in the embodiment of the present invention. Figure 12 and Figure 13 It can be seen that the torque generated by the simultaneous excitation of the stator and rotor sides (i.e., bilateral permanent magnets) in the present invention is approximately equal to the sum of the torques generated by the Halbach array permanent magnet excitation on the stator side only, the spoke array permanent magnet excitation on the stator side, and the permanent magnet excitation on the rotor side only, and the torque fluctuation is greatly improved.

[0071] Example 2

[0072] This embodiment provides a coal mine excavation robot, which includes a cutting part, wherein the cutting motor in the cutting part adopts the strong magnetic field concentration type double-sided excitation magnetic field modulation permanent magnet cutting motor used in the coal mine excavation robot in the above embodiment 1.

[0073] By applying the motor in the above-mentioned embodiment 1 to the coal mine excavation robot in this embodiment, the problem of motor torque density can be well solved, thereby improving the adaptability of the coal mine excavation robot to the working environment.

[0074] Of course, the above description is only a preferred embodiment of the present invention, and the present invention is not limited to the above-mentioned embodiments. It should be noted that all equivalent substitutions and obvious deformation forms made by any technician familiar with this field under the guidance of this specification fall within the substantive scope of this specification and should be protected by the present invention.

Claims

1. A strong magnetic field-concentrating double-sided excitation magnetic field modulation permanent magnet cutting motor for a coal mine excavation robot, comprising a stator, a rotor, and an armature winding, wherein the stator is located outside the rotor, and an air gap is left between the stator and the rotor; characterized in that: The stator includes a stator yoke and stator teeth; wherein the stator yoke is annular; there are multiple stator teeth, and each of the stator teeth is arranged in sequence in the inner circumferential direction of the stator yoke; Five stator permanent magnets are provided at the inner end of each stator tooth; The five stator permanent magnets are arranged in sequence along the tangential direction, wherein three stator permanent magnets are located in the middle of the inner end, and the remaining two stator permanent magnets are located at an edge position of the inner end respectively; Three stator permanent magnets located at the middle of the inner end, including a middle permanent magnet and two side permanent magnets, wherein the two side permanent magnets are located on opposite sides of the middle permanent magnet in the tangential direction; Each side permanent magnet is separated from the stator permanent magnet at an edge position on the corresponding side by an iron pole; The three stator permanent magnets located in the middle of the inner end form a Halbach array arrangement; each side permanent magnet of the Halbach array, the iron pole on the corresponding side, and the stator permanent magnet at the edge position on the corresponding side form a spoke array arrangement; The magnetization direction of the central permanent magnet of the Halbach array is radially outward; the magnetization directions of a side permanent magnet and a stator permanent magnet at an edge position in the same spoke array are both tangential, and the magnetization directions of the two are opposite; The rotor is provided with a plurality of rotor permanent magnets along its circumferential direction; the armature winding is wound on the stator teeth.

2. The strong magnetic concentration type double-sided excitation magnetic field modulation permanent magnet cutting motor for coal mine excavation robot according to claim 1 is characterized in that: The process of improving the torque density of the motor is as follows: While the permanent magnets arranged in the Halbach array have a magnetic focusing effect, the two side permanent magnets of the Halbach array form a spoke array arrangement of permanent magnets with the stator permanent magnets at the side positions corresponding to the inner ends of the stator teeth, thereby introducing another two-fold magnetic focusing effect to increase the magnetomotive force of the stator side permanent magnets and improve the torque density; At the same time, the stator permanent magnets at the inner end edge of the stator teeth have a pole-changing effect, that is, when there are no stator permanent magnets at the edge, the number of pole pairs of the stator side permanent magnets is Z s Pole pairs: When the stator permanent magnets are placed at the edge, the number of stator permanent magnet pole pairs becomes 2Z s For magnetic field modulation motors, when the number of permanent magnet pole pairs on the stator side increases, the low-order harmonic components of the air gap magnetic field generated by the rotor side modulation increase, so the number of armature winding pole pairs is lower, that is, from |Z before pole change r -Z s |Decrease to|Z r -2Z s |, the pole ratio is Z before the pole change r / |Z r -Z s | Increase to Z r / |Z r -2Z s The torque is proportional to the pole ratio, so the pole-changing effect of the stator permanent magnets at the inner edge of the stator teeth can effectively increase the pole ratio and further improve the torque density. where Z s is the number of permanent magnet teeth, Z r Indicates the number of rotor pole pairs; Permanent magnets are placed on both the stator and rotor sides. The magnetic field of the permanent magnets on the stator side is modulated by the rotor teeth, and the magnetic field of the permanent magnets on the rotor side is modulated by the stator teeth, forming a bidirectional magnetic field modulation effect and generating a large number of air gap magnetic field harmonics to improve torque density.

3. The strong magnetic concentration type double-sided excitation magnetic field modulation permanent magnet cutting motor for coal mine excavation robot according to claim 1 is characterized in that: The magnetizing direction of the rotor permanent magnet is radially outward.

4. The strong magnetic concentration type double-sided excitation magnetic field modulation permanent magnet cutting motor for a coal mine excavation robot according to claim 1 is characterized in that: The armature winding adopts a concentrated winding structure.

5. A coal mine excavation robot, comprising a cutting part, characterized in that: The cutting motor in the cutting part adopts the strong magnetic concentration type double-sided excitation magnetic field modulation permanent magnet cutting motor for the coal mine excavation robot as described in any one of claims 1 to 4.

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