Permanent magnet synchronous motor, design method thereof and gyro north seeker

Abstract

The invention discloses a permanent magnet synchronous motor, a design method thereof and a gyro north seeker. The permanent magnet synchronous motor comprises a stator, the stator comprises a stator iron core, N-pole magnets and S-pole magnets, and the N-pole magnets and the S-pole magnets are alternately arranged on the inner side of the stator iron core in the circumferential direction of the stator iron core. The rotor comprises a rotor iron core and a flexible circuit board winding, the rotor iron core and the stator iron core are concentrically arranged, the rotor iron core is located on the inner side of the stator iron core, and the flexible circuit board winding is arranged on the outer side of the rotor iron core in a surrounding mode; the flexible circuit board winding comprises wiring layers stacked in the thickness direction when the flexible circuit board winding is unfolded, each wiring layer comprises a conductive block with a parallelogram plane shape, and the short edge of each conductive block is arranged in the length direction when the flexible circuit board winding is unfolded. And the plurality of conductive blocks are arranged at intervals and in an insulating manner along the length direction of the flexible circuit board winding when the flexible circuit board winding is unfolded.

Description

Technical Field

[0001] The present disclosure relates to the field of electromechanical technology, and in particular to a permanent magnet synchronous motor and a design method thereof, and a gyro north finder. Background Art

[0002] As the driving component of a north-finder based on rotary modulation technology, the motor is one of the key components of the north-finder. The commercial micro motors currently available on the market cannot meet the needs of miniaturized north-finders in terms of volume, so motor miniaturization has also become a very critical design direction for motor design. Summary of the invention

[0003] The present invention provides a permanent magnet synchronous motor and a design method thereof, and a gyro north finder to solve the deficiencies in the related art.

[0004] According to a first aspect of an embodiment of the present disclosure, a permanent magnet synchronous motor is provided, comprising:

[0005] A stator, the stator comprising a stator core, an N-pole magnet and an S-pole magnet, wherein the N-pole magnet and the S-pole magnet are alternately arranged on the inner side of the stator core along the circumferential direction of the stator core;

[0006] A rotor, the rotor comprising a rotor core and a flexible circuit board winding, the rotor core and the stator core are arranged concentrically, the rotor core is located on the inner side of the stator core, and the flexible circuit board winding is arranged around the outer side of the rotor core;

[0007] The flexible circuit board winding includes routing layers stacked along the thickness direction of the flexible circuit board winding when it is unfolded, each routing layer includes a conductive block with a parallelogram planar shape, the short side of the conductive block is arranged along the length direction of the flexible circuit board winding when it is unfolded, and multiple conductive blocks are spaced and insulated along the length direction of the flexible circuit board winding when it is unfolded.

[0008] Optionally, the long sides of the parallelogram are all arranged to be inclined relative to the width direction of the flexible circuit board winding when it is unfolded;

[0009] The number of layers of the routing layers is an even number, and in the stacking direction of the routing layers, the long sides of the conductive blocks of the routing layers arranged as odd numbers have the same inclination direction and the same inclination angle, and the long sides of the conductive blocks of the routing layers arranged as even numbers have the same inclination direction and the same inclination angle;

[0010] The inclination direction of the long sides of the conductive blocks of the wiring layers with even numbers is opposite to the inclination direction of the long sides of the conductive blocks of the wiring layers with odd numbers.

[0011] Optionally, the flexible circuit board winding includes an nth routing layer and an n+1th routing layer, where n is an odd number; the nth routing layer includes a plurality of first conductive blocks, and the n+1th routing layer includes a plurality of second conductive blocks;

[0012] The plurality of second conductive blocks are divided into an overlap area and a first protruding area, wherein the overlap area is located below the nth wiring layer, and the protruding area is partially protruding relative to the nth wiring layer;

[0013] In the overlapped area and the nth wiring layer, the same phase current flows alternately through the first conductive block and the second conductive block;

[0014] The nth wiring layer is provided with a second protruding area protruding relative to the n+1th wiring layer, and the second protruding area is provided with 2m first conductive blocks, the first m first conductive blocks correspond one-to-one to the m input currents of different phases, and the last m first conductive blocks correspond one-to-one to the m output currents of different phases, wherein m is the number of winding phases and is greater than 1;

[0015] Among the 2m second conductive blocks in the first protruding area, the wth second conductive block and the w+mth second conductive block are electrically connected, so that the same-phase current is reversed in the length direction of the flexible circuit board winding when it is unfolded.

[0016] Optionally, the flexible circuit board winding further includes metallized vias, each of which connects a single first conductive block and a single second conductive block.

[0017] Optionally, the flexible circuit board winding is wound around the rotor core K times, where K is greater than or equal to 1;

[0018] The number of conductive blocks in the multiple routing layers of all flexible circuit board windings is equal.

[0019] Optionally, the rotor core comprises multiple layers of concentrically arranged annular silicon steel sheets; and / or,

[0020] The S-pole magnet and the N-pole magnet have the same planar shape and the same corresponding size parameters; the planar shape of the S-pole magnet includes a rectangle and an isosceles trapezoid, and the lower base of the isosceles trapezoid is connected to the long side of the rectangle.

[0021] Optionally, the corners of the S-pole magnet and the N-pole magnet are both provided with arc chamfers; and / or

[0022] The flexible circuit board winding is a two-phase winding.

[0023] According to a second aspect of an embodiment of the present disclosure, a gyro north finder is provided, comprising a permanent magnet synchronous motor as described in any one of the above embodiments.

[0024] According to a third aspect of an embodiment of the present disclosure, a design method for a permanent magnet synchronous motor is provided, which is applied to the permanent magnet synchronous motor as described in any one of the above embodiments, and the design method includes:

[0025] Determine the outer diameter of the stator core, the inner diameter of the rotor core, and the motor torque according to the size of the components to be assembled on the inner ring of the rotor core, the size of the components to be assembled on the outer ring of the stator core, and the load capacity requirements of the permanent magnet synchronous motor;

[0026] According to the motor size and performance requirements of the permanent magnet synchronous motor, determine whether it has brushes, the motor power supply waveform, the number of motor phases and the drive mode;

[0027] Taking the magnetic flux density waveform distortion of the permanent magnet synchronous motor as the optimization objective function, the outer diameter size of the stator core, the inner diameter size of the rotor core and the actual processing and manufacturing requirements as the constraints of the optimization parameters, the static magnetic field simulation is performed on the three-dimensional model of the permanent magnet synchronous motor within the value range of the stator core thickness, the value range of the rotor core thickness, the value range of the air gap thickness, the value range of the winding thickness, the magnet shape and the value range of each magnet size parameter, and the traversal optimization is performed to obtain the optimal solution of the stator core thickness, the optimal solution of the rotor core thickness, the optimal solution of the air gap thickness value, the optimal solution of the winding thickness, the optimal solution of the magnet shape and the optimal solution of each magnet size.

[0028] Optionally, also include:

[0029] Generate a flexible circuit board graphic with positioning lines according to the optimal solution of winding thickness, the optimal solution of rotor core thickness and winding parameters, wherein the positioning lines are used to locate the position of the conductive block after the flexible circuit board winding is wound around the rotor core, and the winding parameters include the number of conductive blocks per pole per phase, the number of winding turns, the insulating gap of the conductive block, the axial margin of the conductive block, the circumferential margin of the conductive block, the inner diameter of the metallized via, the outer diameter of the metallized via, the center distance of the metallized via, the circumferential margin of the metallized via, the axial margin of the inner diameter of the metallized via and the spacing angle of the positioning lines;

[0030] The flexible circuit board pattern is post-processed to obtain a flexible circuit board winding for processing, wherein the post-processing includes setting design rules, batch copper plating of conductive block patterns, adding mechanical layer outlines and design rule checking.

[0031] The technical solution provided by the embodiments of the present disclosure may have the following beneficial effects:

[0032] It can be seen from the above embodiments that the design of the flexible circuit board winding in the present disclosure can be wound around the outside of the rotor core, with light weight, small volume, and is conducive to programmed design and mass production; based on the fact that the inner diameter of the stator core is larger than the outer diameter of the rotor core, more N-pole magnets and S-pole magnets can be embedded to improve the magnetic flux density of the permanent magnet synchronous motor; the flexible circuit board winding can increase the conductive area by setting the conductive block with a parallelogram in the plane shape, increase the force area of ​​the flexible circuit board winding in the magnetic field, improve the space utilization, and based on the permanent magnet synchronous motor of equal volume, it is beneficial to improve the motor torque of the permanent magnet synchronous motor, and under the condition of the same motor torque requirement, it is beneficial to realize the miniaturization of the permanent magnet synchronous motor.

[0033] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0035] Figure 1 is a partial schematic diagram of a permanent magnet synchronous motor according to an exemplary embodiment.

[0036] Figure 2 It is a partial cross-sectional schematic diagram of a permanent magnet synchronous motor according to an exemplary embodiment.

[0037] Figure 3 The figure is a front schematic diagram showing a flexible circuit board winding in an unfolded state according to an exemplary embodiment.

[0038] Figure 4 The figure is a schematic back view of a flexible circuit board winding in an unfolded state according to an exemplary embodiment.

[0039] Figure 5 The diagram is a schematic diagram showing the current flow direction when a flexible circuit board winding is in an unfolded state according to an exemplary embodiment.

[0040] Figure 6 It is a schematic diagram showing the cooperation between an N-pole magnet and a stator core according to an exemplary embodiment.

[0041] Figure 7 The present invention is a flow chart of a design method of a permanent magnet synchronous motor according to an exemplary embodiment.

[0042] Figure 8 The figure is a curve showing the relationship between the circumferential width of a magnet and the average magnetic flux density distortion of a flexible circuit board winding according to an exemplary embodiment.

[0043] Fig. 9 It is a flow chart of another design method of a permanent magnet synchronous motor according to an exemplary embodiment. DETAILED DESCRIPTION

[0044] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0045] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. The singular forms of "a", "said" and "the" used in this disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0046] It should be understood that although the terms first, second, third, etc. may be used in the present disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present disclosure, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0047] Figure 1 is a partial schematic diagram of a permanent magnet synchronous motor according to an exemplary embodiment. Figure 2 FIG. 1 is a partial cross-sectional schematic diagram of a permanent magnet synchronous motor according to an exemplary embodiment. Figure 1 and Figure 2 As shown, the permanent magnet synchronous motor includes a stator and a rotor, wherein the stator includes a stator core 1, an N-pole magnet 3 and an S-pole magnet 4, and the rotor includes a rotor core 2 and a flexible circuit board winding 5. The rotor core 2 is arranged concentrically with the stator core 1, and the rotor core 2 is located on the inner side of the stator core 1. The N-pole magnets 3 and the S-pole magnets 4 are alternately arranged on the inner side of the stator core 1 along the circumferential direction of the stator core 1, and the number of the N-pole magnets 3 and the S-pole magnets 4 are equal. Compared with the solution in the related art in which the magnetic steel is arranged on the rotor and the winding is arranged on the stator, the inner diameter of the stator core 1 in the present disclosure is larger than the outer diameter of the rotor core 2, and more N-pole magnets 3 and S-pole magnets 4 can be embedded to improve the magnetic flux density. For example, if Figure 1 and Figure 2As shown, a plurality of protrusions 11 are provided on the inner side of the stator core 1, and grooves are formed between adjacent protrusions 11, and each groove accommodates a single N-pole magnet 3 or a single S-pole magnet 4. The flexible circuit board winding 5 is arranged around the outer side of the rotor core 2. Through the design of the flexible circuit board winding 5, it can be wound on the outer side of the rotor core, which is light in weight, small in size, and is conducive to programmed design and mass production.

[0048] The flexible circuit board winding 5 includes wiring layers stacked along the thickness direction of the flexible circuit board winding 5 when it is unfolded, and each wiring layer includes a conductive block with a parallelogram shape in the plane, and the short side of the conductive block is arranged along the length direction of the flexible circuit board winding 5 when it is unfolded, and multiple conductive blocks are spaced and insulated along the length direction of the flexible circuit board winding 5 when it is unfolded. Based on this, the conductive blocks arranged in a parallelogram can increase the conductive area, thereby increasing the force area of ​​the flexible circuit board winding 5 in the magnetic field, which is beneficial to improving the motor torque of the permanent magnet synchronous motor based on the permanent magnet synchronous motor of equal volume, and is beneficial to miniaturization of the permanent magnet synchronous motor under the same motor torque requirements. Among them, the number of conductive blocks in multiple wiring layers is equal.

[0049] Among them, the long sides of the parallelogram of the plane shape of the conductive block are all inclined relative to the width direction of the flexible circuit board winding 5 when it is unfolded; the number of routing layers is even, and in the stacking direction of the routing layers, the long sides of the conductive blocks of the routing layers arranged as odd numbers have the same inclination direction and equal inclination angles, and the long sides of the conductive blocks of the routing layers arranged as even numbers have the same inclination direction and equal inclination angles; the long sides of the conductive blocks of the routing layers arranged as even numbers have opposite inclination directions to the long sides of the conductive blocks of the routing layers arranged as odd numbers. For example, the flexible circuit board winding 5 includes four routing layers, then the long sides of the first routing layer and the third routing layer have the same inclination direction and equal inclination angles, the long sides of the second routing layer and the fourth routing layer have the same inclination direction and equal inclination angles, and the long sides of the first routing layer and the second routing layer have opposite inclination directions and equal inclination angles. This is conducive to achieving electrical connection between the first wiring layer and the second wiring layer, and electrical connection between the third wiring layer and the fourth wiring layer, thereby realizing oblique transmission of electrical signals.

[0050] For example, Figure 3 and Figure 4As shown, the flexible circuit board winding 5 includes an nth routing layer 51 and an n+1th routing layer 52, where n is an odd number. The nth routing layer 51 includes a plurality of first conductive blocks 511, and the n+1th routing layer 52 includes a plurality of second conductive blocks 521. The plurality of first conductive blocks 511 are arranged along the length direction of the flexible circuit board winding 5 when it is unfolded, and adjacent first conductive blocks 511 are spaced and insulated. The plurality of second conductive blocks 521 are arranged along the length direction of the flexible circuit board winding 5 when it is unfolded, and adjacent second conductive blocks 521 are spaced and insulated. Figure 3 and Figure 4 As shown, the plane shape of the first conductive block 511 is a parallelogram, the plane shape of the second conductive block 521 is also a parallelogram, and the short side of the parallelogram is arranged along the length direction of the flexible circuit board winding 5, that is, Figure 3 and Figure 4 Arranged in left and right directions.

[0051] In some embodiments, the long sides of the first conductive block 511 and the second conductive block 521 may be arranged parallel to the width direction of the flexible circuit board winding 5 when it is unfolded; in other embodiments, the long sides of the first conductive block 511 and the second conductive block 521 are arranged obliquely relative to the width direction of the flexible circuit board winding 5 when it is unfolded, and the first conductive block 511 and the second conductive block 521 are inclined in opposite directions and have the same inclination angle. Figure 5 As shown in the figure, the first conductive block 511 is tilted to the left relative to the width direction of the flexible circuit board winding 5 when it is unfolded, and the second conductive block 521 is tilted to the right relative to the width direction of the flexible circuit board winding 5 when it is unfolded. Based on this design, it is beneficial to realize the electrical connection between the nth wiring layer 51 and the n+1th wiring layer 52, and the tilted transmission of the electrical signal can be achieved.

[0052] For example, Figure 5 As shown, the plurality of second conductive blocks 521 may be divided into an overlap region 522 and a first protruding region 523, wherein the overlap region 522 is located below the nth wiring layer 51, and the first protruding region is partially protruded relative to the nth wiring layer; for example Figure 5In the figure, the first protruding area 523 is located in the lower right area. In the overlap area 522 of the n+1 routing layer 52 and the n routing layer 51, the same phase current alternately flows through the first conductive block 511 and the second conductive block 521. For example, the flexible circuit board winding 5 also includes a metallized via, each of which connects a single first conductive block 511 and a second conductive block 521 to achieve current transmission between the n routing layer 51 and the n+1 routing layer 52. The n routing layer 511 is provided with a second protruding area 512 protruding relative to the n+1 routing layer 521. The second protruding area 512 is provided with 2m first conductive blocks. The first m first conductive blocks 511 correspond to the m different phase currents input one by one, where m is the number of winding phases and is greater than 1, and the last m first conductive blocks 511 correspond to the m different phase currents output one by one.

[0053] For example, Figure 5 As shown, it is assumed that the flexible circuit board winding 5 is a two-phase winding, for example, the flexible circuit board winding 5 passes the Sin phase current and the Cos phase current, and the phase difference between the Sin phase current and the Cos phase current is 90°. The current indicated by the red line is the Sin phase current, and the current indicated by the green arrow is the Cos phase current. In the direction from left to right, the Sin phase current is input from the first first conductive block 511, transmitted to the fifth first conductive block 511 through the first second conductive block 521, and then transmitted to the ninth first conductive block 511 through the fifth second conductive block 521...; similarly, the Cos phase current is output from the second first conductive block 511, transmitted to the sixth first conductive block 511 through the second second conductive block 521, and then transmitted to the tenth first conductive block 511 after the sixth second conductive block 521..., and so on, the transmission of the first phase current and the second phase current from left to right can be realized.

[0054] It can be seen from the above transmission mode that some of the first conductive blocks 511 and the second conductive blocks 521 are not used to transmit current. Therefore, in order to improve the utilization rate, among the 2m second conductive blocks 521 in the first protruding area 523, the wth second conductive block 521 and the w+mth second conductive block 521 are electrically connected, so that the same-phase current is reversed in the length direction when the flexible circuit board winding 5 is unfolded. That is, Figure 5As shown in , the first second conductive block 521 from right to left is electrically connected to the third second conductive block 521, so that the Sin phase current can flow from right to left, and the second second conductive block 521 from right to left is electrically connected to the fourth second conductive block 521, so that the cos phase current can flow from left to right, so that each first conductive block 511 and each second conductive block 521 are utilized to flow through the current, thereby improving the utilization rate. In addition, the input ends of the m phase currents are arranged side by side in the first m first conductive blocks 511 of the 2m first conductive blocks protruding from the nth wiring layer 51 relative to the n+1th wiring layer 52, and the output ends of the m phase currents are arranged side by side in the last m first conductive blocks 511, so that the input and output pads of the flexible circuit board winding 5 are relatively close in space, which is convenient for wiring and is conducive to realizing the input and output design of the flexible circuit board winding 5, and the input and output ends of the m phase currents are arranged in sequence, which can reduce the probability of short circuit compared to the alternating arrangement.

[0055] Of course, in order to avoid short circuit between the Sin phase current and the Cos phase current, the second second conductive block 521 and the fourth second conductive block 521 from right to left can be connected through the metal part arranged on the n+1th wiring layer 52, and the first second conductive block 521 and the third second conductive block 521 from right to left can be connected through the metallized via and the metal part arranged on the nth wiring layer 51. Alternatively, the second second conductive block 521 and the fourth second conductive block 521 from right to left can be connected through the metallized via and the metal part arranged on the nth wiring layer 51, and the first second conductive block 521 and the third second conductive block 521 from right to left can be connected through the metallized via and the metal part arranged on the nth wiring layer 51.

[0056] The above description is made by taking the nth routing layer 51 and the n+1th routing layer 52 as examples. In other embodiments, the same flexible circuit board winding 5 may also include the pth routing layer and the p+1th routing layer, where p=n+2. In this case, in order to realize the flow of the current path, after the phase current flows back to the left side of the n+1th routing layer 52, the second conductive block 521 of the n+1th routing layer 52 may be electrically connected to the protruding area on the left side of the pth routing layer, and then the circuit between the pth routing layer and the p+1th routing layer may be connected with reference to the routing rules of the nth routing layer 51 and the n+1th routing layer 52. When the flexible circuit board winding 5 includes more layers of routing layers, the above embodiment may be referred to for implementation.

[0057] In each of the above embodiments, the flexible circuit board winding 5 is wound around the rotor core 2 with K turns, K being greater than or equal to 1; in the radially outward direction of the rotor core, in the 1st to Kth turns, the number of first conductive blocks in each turn is equal to the number of second conductive blocks, and the number of first conductive blocks in each turn is equal to the number of motor phases × the number of pole pairs × 2 × the number of bars per phase per pole - the number of motor phases × the number of bars per phase per pole × 2.

[0058] In some embodiments, the rotor core 2 includes multiple layers of concentrically arranged annular silicon steel sheets, which is beneficial to reducing the eddy current loss of the motor, thereby reducing the resistance torque of the motor. In other words, the rotor core 2 is formed by stacking multiple layers of annular silicon steel sheets, and the inner ring space of the rotor core 2 can be used to arrange motor parts or configure mechanical parts or electrical parts of the equipment end of the permanent magnet synchronous motor, thereby improving the compactness of the permanent magnet synchronous motor and the compactness of the equipment end, which is beneficial to miniaturization of the permanent magnet synchronous motor.

[0059] In some embodiments, the S-pole magnet 4 and the N-pole magnet 3 have the same shape and the same corresponding size parameters; Figure 6 As shown, the cross section of the S-pole magnet 4 includes a rectangle and an isosceles trapezoid, the lower base of the isosceles trapezoid is connected to the long side of the rectangle, and the S-pole magnet is a symmetrical structure; the cross-sectional shape and various dimensional parameters of the N-pole magnet are the same as those of the S-pole magnet 4. Through this structural shape design, the magnetic flux density distortion of the permanent magnet synchronous motor can be reduced. Among them, the edges and corners of the S-pole magnet 4 and the N-pole magnet 3 are both provided with arc chamfers to reduce scratching.

[0060] The present disclosure also provides a gyro north finder, which includes the permanent magnet synchronous motor described in any of the above embodiments. The permanent magnet synchronous motor using radial magnetic flux is applied to the gyro north finder, which not only improves the space utilization rate through the inner ring space of the rotor core 2, reduces the motor volume, and meets the needs of miniaturized gyro north finders, but also has a simple motor structure, better dynamic and static performance, adopts a direct drive mode, does not require a reducer, saves space, and ensures the accuracy and reliability of the motor.

[0061] Based on the technical solution of the present disclosure, a design method of a permanent magnet synchronous motor is also provided, which is applied to the permanent magnet synchronous motor described in any of the above embodiments. Figure 7 As shown, the design method includes the following steps:

[0062] In step 701, the outer diameter of the stator core, the inner diameter of the rotor core and the motor torque are determined according to the size of the components required to be assembled on the inner ring of the rotor core, the size of the components assembled on the outer ring of the stator core and the load capacity requirement of the permanent magnet synchronous motor.

[0063] In step 702, whether there are brushes, the motor power supply waveform, the number of motor phases and the driving mode are determined according to the motor size and performance requirements of the permanent magnet synchronous motor.

[0064] In this embodiment, the application of permanent magnet synchronous motor to gyro north finder is taken as an example. In order to improve the space utilization rate, considering that the axial magnetic attraction of the disc motor has an uncontrollable influence on the bearing preload state, a radial flux structure is selected; and since the speed required by the gyro north finder is generally not high, on the other hand, the reducer needs to occupy a certain volume, and there is a transmission gap problem, which reduces the accuracy and reliability of the motor, so a direct drive method is selected; although the structure and control of the brushless DC motor are simple, there is a friction problem, which increases the system noise and reduces the life, so a brushless solution is selected. Common brushless DC motors (brushless direct current motor, referred to as BLDC) and permanent magnet synchronous motors (permanent magnet synchronous motor, referred to as PMSM) are both brushless structures, using sinusoidal wave power supply instead of BLDC square wave power supply, eliminating torque pulsation during commutation, and having more stable running performance, with better static and dynamic characteristics, and the permanent magnet synchronous motor can be powered by a DC power supply in terms of control mode, which is convenient to use.

[0065] Based on this, it can be determined that a radial flux two-phase permanent magnet synchronous motor is used, with a brushless structure, sinusoidal waveform power supply and direct drive power supply. Permanent magnet synchronous motors are powered by sinusoidal current. Compared with brushless DC motors, they omit collector rings and brushes in structure, have a simpler structure, eliminate torque pulsation during commutation, have smoother operating performance, improved operating reliability, and are small in size, making them widely used in miniaturized carrier scenarios.

[0066] In step 703, the magnetic flux density waveform distortion of the permanent magnet synchronous motor is used as the optimization objective function, the outer diameter of the stator core, the inner diameter of the rotor core and the actual processing and manufacturing requirements are used as constraints of the optimization parameters, and within the value range of the stator core thickness, the value range of the rotor core thickness, the value range of the air gap thickness, the value range of the winding thickness, the magnet shape and the value range of each magnet size parameter, the static magnetic field simulation is performed on the three-dimensional model of the permanent magnet synchronous motor, and the optimal solution of the stator core thickness, the optimal solution of the rotor core thickness, the optimal solution of the air gap thickness, the optimal solution of the winding thickness, the optimal solution of the magnet shape and the optimal solution of each magnet size are obtained through traversal optimization.

[0067] In the embodiments of the present disclosure, due to the structure of the motor, the waveform of the magnetic flux density cannot be an ideal sine waveform. The various harmonics contained in the motor will cause torque fluctuations, thereby generating motor noise and vibration problems, resulting in low motor energy efficiency, high power consumption and reduced life. In addition, torque fluctuations will also affect the subsequent high-precision control of the motor. This article introduces distortion to quantitatively describe the maximum distortion degree of the air gap magnetic flux density waveform relative to the standard sine wave.

[0068]

[0069] Among them, r is the calculated air gap flux density, s is the standard sine function value, A s is the amplitude of the standard sine wave. The smaller the maximum distortion is, the closer the magnetic flux density waveform is to the sine wave. Therefore, the magnetic flux density waveform distortion can be used as the optimization objective function.

[0070] For example, the actual processing and manufacturing requirements include: the thickness of the stator core 1 and the rotor core 2 needs to be as large as possible within the allowable range to prevent deformation during processing; the magnet thickness is at least 1.2mm to ensure that the performance of the processed magnet can reach the nominal performance; the depth of the magnet embedded in the stator core 1 is at least half of the magnet thickness to reduce magnetic leakage; the air gap thickness is at least 0.3mm to prevent the air gap thickness from being too small due to processing errors. A too small air gap may cause friction between the stator core 1 and the rotor core 2, which is not conducive to the heat dissipation of the motor; the stator core is made of DT4 material, and its magnetic flux density cannot exceed the threshold to prevent magnetic saturation from causing motor overheating. Of course, there may be other actual processing and manufacturing requirements, which will not be repeated here.

[0071] In this embodiment, multiple parameters such as stator core thickness, rotor core thickness, air gap thickness, winding thickness, magnet shape and various magnet size parameters can be optimized in sequence, and another parameter can be optimized when the previous parameter obtains the optimal solution.

[0072] For example, taking magnet selection as Figure 6 Taking the structure shown in as an example, the optimized parameters of the magnet include the circumferential width L_width of the magnet, the radial thickness L_thick of the magnet, the thickness L_insert of the magnet embedded in the stator core, the circumferential width L_incW of the inclined plane, the radial thickness L_incT of the inclined plane, and the fillet radius at the corners. On the basis of setting the axial length, radial thickness, rotor core thickness, stator core thickness, air gap thickness, winding thickness, magnet thickness embedded in the stator core, radial thickness of the inclined plane, circumferential width of the inclined plane, and fillet radius of the magnet, only the relationship between the circumferential width L_width of the magnet and the average magnetic flux density distortion of the winding is considered as follows: Figure 8As shown. It can be seen that the relationship between the two is V-shaped, and the magnetic flux density distortion has a minimum value within the simulation value range, and the corresponding magnet circumferential width L_width is 3.18mm. After determining the value of the magnet circumferential width L_width parameter, the other shape parameters such as the radial thickness of the inclined surface, the circumferential width of the inclined surface, and the fillet radius are traversed and optimized to obtain the final three-dimensional structural parameters of the motor.

[0073] For another example, multiple possible combinations can be obtained within the parameter range of stator core thickness, rotor core thickness, air gap thickness, winding thickness, magnet shape, magnet circumferential width L_width, magnet radial thickness L_thick, magnet thickness embedded in the core L_insert, inclined surface circumferential width L_incW, inclined surface radial thickness L_incT and fillet radius at corners, and the optimal value of each parameter can be traversed for the multiple possible combinations.

[0074] In this technical solution, the permanent magnet synchronous motor is divided into a stator and a rotor for modular and standardized design. Not only can the permanent magnet synchronous motor be accurately customized according to needs, but the programmed design method also improves design efficiency and facilitates mass production.

[0075] In some other embodiments, Fig. 9 As shown, the design method also includes steps 704 and 705. In step 704, a flexible circuit board pattern with positioning lines is generated according to the optimal solution of the winding thickness, the optimal solution of the rotor core thickness and the winding parameters. The positioning lines are used to locate the position of the conductive block after the flexible circuit board winding is wound on the rotor core. The winding parameters include the number of conductive blocks per pole and per phase, the number of winding turns, the insulating gap of the conductive block, the axial margin of the conductive block, the circumferential margin of the conductive block, the inner diameter of the metallized via hole, the outer diameter of the metallized via hole, the center spacing of the metallized via hole, the circumferential margin of the metallized via hole, the axial margin of the metallized via hole and the spacing angle of the positioning lines. In step 705, the flexible circuit board pattern is post-processed to obtain a flexible circuit board winding for processing. The post-processing includes setting design rules, batch copper plating of the conductive block pattern, adding a mechanical layer outline and design rule checking. The generation of the flexible circuit board winding based on the programmatic design can greatly improve the design efficiency. The axial direction in the above-mentioned dimension definitions refers to the axial direction of the rotor core 2 , and the circumferential direction refers to the circumferential direction of the rotor core 2 .

[0076] The flexible circuit board winding is made of multi-layer flexible PCB and can be wound on the rotor core. It has the advantages of light weight, small size, easy program design and mass production. In order to increase the effective conductor area and reduce the complexity of the winding structure, a two-phase winding is adopted, and the conductive blocks are set at an angle. In order to ensure that each circle of conductive blocks wound on the rotor core is aligned, positioning lines are designed on the surface of the flexible circuit board winding, and the interval between adjacent positioning lines is 360°.

[0077] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the disclosure disclosed herein. The present disclosure is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The description and examples are to be considered exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.

[0078] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A permanent magnet synchronous motor, characterized in that: include: A stator, the stator comprising a stator core, an N-pole magnet and an S-pole magnet, wherein the N-pole magnet and the S-pole magnet are alternately arranged on the inner side of the stator core along the circumferential direction of the stator core; A rotor, the rotor comprising a rotor core and a flexible circuit board winding, the rotor core and the stator core are arranged concentrically, the rotor core is located on the inner side of the stator core, and the flexible circuit board winding is arranged around the outer side of the rotor core; The flexible circuit board winding includes routing layers stacked along the thickness direction of the flexible circuit board winding when it is unfolded, each routing layer includes a conductive block with a parallelogram planar shape, the short side of the conductive block is arranged along the length direction of the flexible circuit board winding when it is unfolded, and multiple conductive blocks are spaced and insulated along the length direction of the flexible circuit board winding when it is unfolded.

2. The permanent magnet synchronous motor according to claim 1, characterized in that: The long sides of the parallelogram are all arranged to be inclined relative to the width direction of the flexible circuit board winding when it is unfolded; The number of layers of the routing layers is an even number, and in the stacking direction of the routing layers, the long sides of the conductive blocks of the routing layers arranged as odd numbers have the same inclination direction and the same inclination angle, and the long sides of the conductive blocks of the routing layers arranged as even numbers have the same inclination direction and the same inclination angle; The inclination direction of the long sides of the conductive blocks of the wiring layers with even numbers is opposite to the inclination direction of the long sides of the conductive blocks of the wiring layers with odd numbers.

3. The permanent magnet synchronous motor according to claim 2, characterized in that: The flexible circuit board winding includes an nth routing layer and an n+1th routing layer, where n is an odd number; the nth routing layer includes a plurality of first conductive blocks, and the n+1th routing layer includes a plurality of second conductive blocks; The plurality of second conductive blocks are divided into an overlap area and a first protruding area, wherein the overlap area is located below the nth wiring layer, and the protruding area is partially protruding relative to the nth wiring layer; In the overlapped area of ​​the n+1th routing layer and the nth routing layer, the same phase current flows alternately through the first conductive block and the second conductive block; The nth wiring layer is provided with a second protruding area protruding relative to the n+1th wiring layer, and the second protruding area is provided with 2m first conductive blocks, the first m first conductive blocks correspond one-to-one to the m input currents of different phases, and the last m first conductive blocks correspond one-to-one to the m output currents of different phases, wherein m is the number of winding phases and is greater than 1; Among the 2m second conductive blocks in the first protruding area, the wth second conductive block and the w+mth second conductive block are electrically connected, so that the same-phase current is reversed in the length direction of the flexible circuit board winding when it is unfolded.

4. The permanent magnet synchronous motor according to claim 3, characterized in that: The flexible circuit board winding further includes metallized vias, each of which connects a single first conductive block and a single second conductive block.

5. The permanent magnet synchronous motor according to claim 1, characterized in that: The flexible circuit board winding is wound around the rotor core K times, where K is greater than or equal to 1; The number of conductive blocks in the multiple routing layers of all flexible circuit board windings is equal.

6. The permanent magnet synchronous motor according to claim 1, characterized in that: The rotor core comprises multiple layers of concentrically arranged annular silicon steel sheets; and / or, The S-pole magnet and the N-pole magnet have the same planar shape and the same corresponding size parameters; the planar shape of the S-pole magnet includes a rectangle and an isosceles trapezoid, and the lower base of the isosceles trapezoid is connected to the long side of the rectangle.

7. The permanent magnet synchronous motor according to claim 1, characterized in that: The corners of the S-pole magnet and the N-pole magnet are both provided with arc chamfers; and / or The flexible circuit board winding is a two-phase winding.

8. A gyro north finder, characterized in that: It comprises a permanent magnet synchronous motor as claimed in any one of claims 1 to 7.

9. A design method for a permanent magnet synchronous motor, characterized in that: Applied to the permanent magnet synchronous motor according to any one of claims 1 to 7, the design method comprises: Determine the outer diameter of the stator core, the inner diameter of the rotor core, and the motor torque according to the size of the components to be assembled on the inner ring of the rotor core, the size of the components to be assembled on the outer ring of the stator core, and the load capacity requirements of the permanent magnet synchronous motor; According to the motor size and performance requirements of the permanent magnet synchronous motor, determine whether it has brushes, the motor power supply waveform, the number of motor phases and the drive mode; Taking the magnetic flux density waveform distortion of the permanent magnet synchronous motor as the optimization objective function, the outer diameter size of the stator core, the inner diameter size of the rotor core and the actual processing and manufacturing requirements as the constraints of the optimization parameters, the static magnetic field simulation is performed on the three-dimensional model of the permanent magnet synchronous motor within the value range of the stator core thickness, the value range of the rotor core thickness, the value range of the air gap thickness, the value range of the winding thickness, the magnet shape and the value range of each magnet size parameter, and the traversal optimization is performed to obtain the optimal solution of the stator core thickness, the optimal solution of the rotor core thickness, the optimal solution of the air gap thickness value, the optimal solution of the winding thickness, the optimal solution of the magnet shape and the optimal solution of each magnet size.

10. The method for designing a permanent magnet synchronous motor according to claim 9, further comprising: Generate a flexible circuit board graphic with positioning lines according to the optimal solution of winding thickness, the optimal solution of rotor core thickness and winding parameters, wherein the positioning lines are used to locate the position of the conductive block after the flexible circuit board winding is wound around the rotor core, and the winding parameters include the number of conductive blocks per pole per phase, the number of winding turns, the insulating gap of the conductive block, the axial margin of the conductive block, the circumferential margin of the conductive block, the inner diameter of the metallized via, the outer diameter of the metallized via, the center spacing of the metallized via, the circumferential margin of the metallized via, the axial margin of the metallized via and the spacing angle of the positioning lines; The flexible circuit board pattern is post-processed to obtain a flexible circuit board winding for processing, wherein the post-processing includes setting design rules, batch copper plating of conductive block patterns, adding mechanical layer outlines and design rule checking.

Images