A split-type alternating-pole permanent magnet motor based on dual magnetic field modulation effect

Abstract

The present invention discloses a split-type alternating-pole permanent magnet motor based on a dual-magnetic field modulation effect. This motor belongs to the field of motor design and is composed of a rotor core, split-type permanent magnets, stator permanent magnets, a stator core, and windings. It is characterized by the use of split-type alternating-pole permanent magnet excitation on the rotor. The radially magnetized surface-mounted permanent magnets based on the motor's initial design are separated along their radial and circumferential centerlines into three permanent magnets: one outer permanent magnet of full width and two inner permanent magnets of half width and equal height. The two inner permanent magnets rotate toward the inner surface of the rotor with the circumferential outer separation point of the permanent magnets as the center point, and can form a split-type permanent magnet structure with the outer permanent magnets in an isosceles trapezoidal, rectangular, or triangular-rectangular combination. This permanent magnet structure has high excitation capability at the same permanent magnet dosage, and regulates the air gap magnetic field distribution within the motor, reducing harmonic distortion. The motor disclosed in the present invention has the advantages of high power factor, high torque density, and high efficiency.

Description

Technical Field

[0001] The invention belongs to the field of motor design and relates to a separated alternating-pole permanent magnet motor based on a dual-magnetic field modulation effect. Background Art

[0002] Among existing technologies, the development of the new energy vehicle industry is an important engine for the transformation and development of the automotive industry. Through the development of the new energy vehicle industry, the electrification of transportation and the transformation of new energy vehicles to pure electric drive have been promoted; and motors play an important role in modern industry; in addition, due to their theoretical zero emissions, motors are particularly popular in clean energy systems, such as electric vehicles and wind turbines, which aim to solve energy crises and environmental pollution problems.

[0003] Permanent magnet synchronous motors (PMSMs), with their high efficiency and high power density, are being widely researched as a viable alternative to conventional electrically excited motors in various applications. Currently, most motor drive systems typically utilize a "motor + mechanical reduction gearbox" combination to achieve high torque output from the entire motor system. However, this approach inevitably leads to a number of issues, including bulk, low reliability, and high friction and noise. To address these issues, the magnetic gearing effect has been introduced into PMSMs, creating field-modulated motors. Currently, field-modulated motors mostly utilize a single-sided permanent magnet excitation structure, consisting of a rotor permanent magnet structure and a stator permanent magnet structure. In rotor PMSMs, the spatial harmonics generated by the rotor permanent magnet excitation are modulated by the stator-side modulation poles and then interact with the spatial harmonics generated by the energized armature winding to generate electromagnetic torque. In stator PMSMs, the spatial harmonics of the magnetic field excited by the stator permanent magnets are first modulated by the rotor modulation poles and then interact with the spatial harmonics generated by the energized armature field to generate electromagnetic torque. However, conventional field-modulated motors utilize a single permanent magnet excitation, resulting in low internal motor space utilization.

[0004] To address this issue, motor researchers have adopted a permanent magnet motor structure that uses both stator and rotor permanent magnet excitation, known as a dual-field modulation motor. This motor utilizes a dual-field modulation effect, where the stator and rotor permanent magnet excitation fields are modulated by the rotor and stator core poles, respectively. This creates a bilateral magnetic field modulation, increasing the number and amplitude of operating harmonics and improving the motor's torque output.

[0005] The invention discloses a separated alternating-pole permanent magnet motor based on a dual-magnetic field modulation effect. The motor has large output torque, high internal space utilization, high torque density and high permanent magnet utilization. Summary of the Invention

[0006] In response to the above problems, the present invention aims to further improve the torque output capability of magnetic field modulation motors. Based on the exploration of new rotor permanent magnet arrays and dual magnetic field modulation motor technologies, the present invention discloses a split-type alternating-pole permanent magnet motor based on the dual magnetic field modulation effect.

[0007] The rotor adopts a split-type alternating-pole permanent magnet excitation, wherein the radially magnetized surface-mounted permanent magnet based on the initial design of the motor is separated into three permanent magnets along its radial centerline and circumferential centerline, namely, an outer permanent magnet of full width and two inner permanent magnets of half width and equal height. The two inner permanent magnets are rotated toward the inner surface of the rotor with the circumferential outer separation point of the permanent magnet as the circle point. The angle value is calculated based on the optimal air gap magnetic field distribution required by the initial design and is less than 90 degrees, so as to ensure magnetic concentration and magnetic field regulation capabilities and reduce the harmonic distortion rate of the air gap magnetic field;

[0008] The permanent magnet excitation magnetic field on the rotor and the permanent magnet excitation magnetic field on the stator are modulated by the stator teeth and the rotor core respectively and then coupled with the armature winding, and electromechanical energy conversion is performed in the air gap magnetic field based on the dual magnetic field modulation effect;

[0009] The present invention has the characteristics of strong rotor permanent magnet excitation capability, a large number of working harmonics in the air gap magnetic field and high amplitude, and based on the dual magnetic field modulation effect, the motor has the advantages of high output torque, high torque density, high space utilization, high efficiency, high power factor, low harmonic distortion rate, low cogging torque, low torque pulsation, etc. It is suitable for occasions requiring high output torque and high efficiency such as electric vehicles and more electric aircraft drives, and has good development prospects.

[0010] The technical solution of the present invention: The present invention provides a split-type alternating-pole permanent magnet motor based on a dual magnetic field modulation effect, comprising a rotor and a stator;

[0011] The rotor includes a rotating shaft, bearings, a rotor core, separate permanent magnets and rotor core poles.

[0012] The stator includes a stator permanent magnet, a stator tooth top, a stator core and an armature winding;

[0013] The stator adopts a stator alternating pole permanent magnet structure composed of stator permanent magnets and stator tooth tops to assist excitation and adjust the magnetic field distribution inside the motor;

[0014] The rotor uses split-type alternating-pole permanent magnet excitation. The radially magnetized surface-mounted permanent magnets (SPMs) based on the motor's initial design are separated along their radial and circumferential centerlines into three permanent magnets: one full-width outer permanent magnet and two half-width inner permanent magnets of equal height. The two inner permanent magnets are rotated toward the rotor's inner surface at an angle calculated based on the optimal air-gap magnetic field distribution required by the initial design and less than 90 degrees, ensuring magnetic field concentration and magnetic field regulation capabilities while reducing the air-gap magnetic field harmonic distortion.

[0015] The stator side permanent magnet excitation magnetic field (stator permanent magnet) and the rotor side permanent magnet excitation magnetic field (external permanent magnet) are modulated by the rotor core pole and the stator tooth top respectively, forming a bilateral magnetic field modulation, which increases the number and amplitude of the working harmonics and improves the motor torque output capacity.

[0016] The two inner permanent magnets of the rotor rotate toward the inner surface of the rotor with the circumferential outer separation point of the surface-mounted permanent magnet as the center point. The separation point is radially away from the upper and lower surfaces of the surface-mounted permanent magnet by more than 1 / 4 of the height of the permanent magnet, and circumferentially away from the circumferential center line of the surface-mounted permanent magnet by more than 1 / 8 of the width of the permanent magnet.

[0017] Furthermore, the rotation angle of the two inner permanent magnets toward the inner surface of the rotor with the circumferential outer separation point of the permanent magnets as the circle point is calculated based on the optimal air gap magnetic field distribution required by the initial design and is less than 90 degrees, so as to ensure the magnetic field concentration and magnetic field regulation capabilities and reduce the air gap magnetic field harmonic distortion rate.

[0018] Furthermore, the widths of the two inner permanent magnets must be equal, the maximum width of the two inner permanent magnets is the width of the outer permanent magnets, and the minimum width is 1 / 8 of the width of the outer permanent magnets.

[0019] Furthermore, the separation point is on the circumferential outside of the surface-mounted permanent magnet, the rotation angle of the inner permanent magnet is less than 90 degrees, and the separated permanent magnet is an isosceles trapezoidal structure;

[0020] The separation point is on the outer side of the surface-mounted permanent magnet, the rotation angle of the inner permanent magnet is equal to 90 degrees, and the separated permanent magnet has a rectangular structure;

[0021] The separation point is not on the circumferential outside of the permanent magnet, the rotation angle of the inner permanent magnet is less than 90 degrees, and the separation type permanent magnet is a triangular-rectangular structure.

[0022] The stator permanent magnet and the stator tooth top form a stator alternating pole permanent magnet structure to assist in excitation and adjust the magnetic field distribution in the motor; the separated permanent magnet and the rotor core pole form a rotor alternating pole permanent magnet structure to serve as the main excitation source to establish the main magnetic circuit in the motor;

[0023] The permanent magnet excitation magnetic field on the rotor (inner permanent magnet) and the permanent magnet excitation magnetic field on the stator (stator permanent magnet) are modulated by the stator teeth and rotor core poles respectively, and then coupled with the armature winding. Electromechanical energy conversion is performed in the air gap magnetic field based on the dual magnetic field modulation effect.

[0024] Due to the above two-layer modulation effect, the motor has a higher operating harmonic amplitude than the traditional single-field modulation motor.

[0025] Furthermore, according to the magnetic field modulation theory, when a three-phase sinusoidal alternating current is injected into the armature winding to generate a pole pair number P aWhen the armature magnetic field is in the space, the number of pole pairs of the rotor surface-mounted permanent magnet is P r , the number of stator permanent magnet pole pairs is P s , the number of rotor core poles N r , the number of stator core poles N s , satisfying the following relationship: P a =|P r -P s |,P s =N s , P r =N r .

[0026] The beneficial effects of the present invention are as follows: The characteristics of the present invention are: 1. On the basis of a single magnetic field modulation motor, by applying permanent magnets at the stator slots, a compact motor topology structure is obtained, which further improves the internal space utilization of the motor; 2. The relative movement of the stator alternating pole permanent magnet array and the rotor alternating pole permanent magnet array increases the working harmonic amplitude through the dual magnetic field modulation effect, improves the air gap magnetic field utilization, reduces the leakage flux, and thus further improves the torque density; 3. The rotor built-in permanent magnet array constitutes the main magnetic circuit, the air gap magnetic density is high, the harmonic distortion is small, and the electromechanical energy conversion rate is high; 4. The stator armature adopts a fractional slot concentrated winding connection method, and the motor has the advantages of low loss, high efficiency, short winding ends, and small cogging torque. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0028] Figure 2 Schematic diagram of a separated permanent magnet structure in which two inner permanent magnets and an outer permanent magnet form an isosceles trapezoid, a rectangle, and a triangle-rectangle combination;

[0029] Figure 3 Schematic diagram of a motor in which the permanent magnet and the external permanent magnet form an isosceles trapezoidal structure;

[0030] Figure 4 This is a schematic diagram of the motor structure in which the permanent magnet and the external permanent magnet form a rectangular structure;

[0031] Figure 5 This is a schematic diagram of the motor structure in which the permanent magnet and the external permanent magnet form a triangle-rectangle structure;

[0032] Figure 6 is a schematic diagram of the stator and its magnetization direction in the present invention;

[0033] Figure 7 This is a schematic diagram of the rotor and its magnetization direction in the present invention;

[0034] Figure 8is a two-dimensional cross-sectional view of the present invention;

[0035] Figure 9 This is a diagram of the rotor hybrid permanent magnet excitation structure in the present invention;

[0036] Figure 10-11 is a structural diagram of a dual-field modulation motor with other stator alternating pole structures according to an embodiment of the present invention;

[0037] In the figure: 1 is a rotor, 101 is a rotor core, 102 is a split permanent magnet, 102-1 is an outer permanent magnet, 102-2 is an inner permanent magnet, and 103 is a rotor core pole;

[0038] 2 is the stator, 201 is the stator permanent magnet, 202 is the stator tooth top, 203 is the stator core, and 204 is the armature winding;

[0039] 401 is the housing, 402 is the shaft, 403 is the bearing,

[0040] 601 is a high energy product permanent magnet, and 602 is a low energy product permanent magnet. DETAILED DESCRIPTION

[0041] In order to more clearly illustrate the technical solution of the present invention, the technical solution of the present invention is further described in detail below with reference to the accompanying drawings:

[0042] As shown in the figure, the present invention describes a separated alternating-pole permanent magnet motor based on a dual magnetic field modulation effect, comprising a stator 2, a rotor 1, an armature winding 204, a stator permanent magnet array (stator permanent magnet 201, stator tooth top 202, stator core 203), a rotor outer permanent magnet array (outer permanent magnet 102-1) and a rotor inner permanent magnet array (inner permanent magnet 102-2), wherein an air gap is left between the stator 2 and the rotor 1.

[0043] The stator armature (armature winding 204 ) adopts a fractional slot concentrated winding connection mode, and a three-phase sinusoidal alternating current is passed through the corresponding stator slots to the armature winding 204 to generate a rotating armature magnetic field.

[0044] Furthermore, the present invention adopts a stator alternating-pole permanent magnet structure composed of stator permanent magnets and stator tooth tops; a separated alternating-pole permanent magnet excitation (separate permanent magnet 102) is adopted on the rotor 1, wherein the radially magnetized surface-mounted permanent magnet based on the initial design of the motor is separated into three permanent magnets along its radial center line and circumferential center line, namely, an outer permanent magnet 102-1 of full width and two inner permanent magnets 102-2 of half width and equal height. The two inner permanent magnets 102-2 rotate toward the inner surface of the rotor 1 with the circumferential outer separation point of the surface-mounted permanent magnet as the center point, and can form a separated permanent magnet structure with the outer permanent magnet 102-1 in the form of an isosceles trapezoid, a rectangle, or a triangle-rectangle combination.

[0045] The two inner permanent magnets 102 - 2 are arranged to form an optimized magnetic field concentration structure. The excitation direction of this structure is the same as that of the outer permanent magnet 102 - 1 , which improves the excitation and optimizes the air gap magnetic field distribution.

[0046] This permanent magnet excitation structure has high excitation capability under the same permanent magnet dosage, and adjusts the air gap magnetic field distribution in the motor to reduce the harmonic distortion rate;

[0047] The separated permanent magnets 102 and the rotor core poles 103 form a rotor alternating pole permanent magnet structure, which serves as a main excitation source to establish a main magnetic circuit in the motor.

[0048] Since the stator 2 and the outer layer of the rotor 1 have alternately arranged split permanent magnets 102, and the stator tooth tops 202 and the stator permanent magnets 201 form an alternating pole structure, the outer permanent magnets 102-1 in the split permanent magnets 102 and the rotor core poles 103 form an alternating pole structure;

[0049] When the motor is working, the permanent magnet excitation magnetic field on the rotor 1 (external permanent magnet 102-1) and the permanent magnet excitation magnetic field on the stator (stator permanent magnet 201) are modulated by the stator teeth (stator tooth top 202) and the rotor core pole 103 respectively to produce a dual magnetic field modulation effect, that is, the rotor permanent magnet excitation magnetic field (external permanent magnet 102-1) is modulated by the stator tooth top 202,

[0050] The stator permanent magnet excitation magnetic field (stator permanent magnet 201) is modulated by the rotor core pole 103 to produce a bidirectional modulation effect, forming an effective harmonic component of a certain pole pair number and rotation speed in the air gap, and using this harmonic component to effectively couple with the armature winding, thereby realizing electromechanical energy conversion.

[0051] The number of stator tooth tops 202 is N s , the number of rotor core poles 103 is N r , the number of pole pairs of the stator permanent magnet 201 is P s The number of pole pairs of the rotor surface-mounted permanent magnet (external permanent magnet 102-1) is P r , a three-phase sinusoidal alternating current is passed into the stator d armature winding 204 to generate a pole pair number P a The space armature magnetic field satisfies the following relationship: P a =|P r -P s |,P s =N s , P r =N r .

[0052] The present invention has the advantages of high output torque, high torque density, high space utilization, high efficiency, high power factor, low harmonic distortion, low cogging torque, and low torque pulsation. It is suitable for electric vehicles, multi-electric aircraft drives and other occasions requiring high output torque and high efficiency and has good development prospects.

[0053] Example 1

[0054] like Figure 1 、 Figure 2 As shown, the present invention discloses a separated alternating pole permanent magnet motor based on the dual magnetic field modulation effect, which includes a stator 2, a rotor 1, an armature winding 204, a stator permanent magnet array (stator permanent magnet 201, stator tooth top 202, stator core 203), a rotor outer layer permanent magnet array (outer permanent magnet 102-1) and a rotor inner layer permanent magnet array (inner permanent magnet 102-2), wherein an air gap is left between the stator 2 and the rotor 1. Stator teeth are evenly distributed along the circumference of the stator core 203, and a stator permanent magnet 201 is applied between two adjacent stator tooth tops 202; the separated permanent magnets 102-1 and the core poles 103 constitute a rotor alternating pole permanent magnet structure, and the stator permanent magnets 201 and the stator tooth tops 202 constitute a stator alternating pole permanent magnet structure, and the armature winding 204 is embedded in radially oriented stator slots; the outer surface of the rotor 1 is evenly attached with radially magnetized and alternately arranged permanent magnets 102-1 along the circumference, and two inner permanent magnets 102-2 of equal height and half the width are rotated toward the inner surface of the rotor 1 with the circumferential outer separation point of the surface-mounted permanent magnets as the center point to form a rotor inner permanent magnet array (inner permanent magnet 102-2);

[0055] The rotating shaft 402 , the rotor 1 , the rotor permanent magnets 102 , and the rotor core poles 103 are all coaxially sleeved.

[0056] Specifically, such as Figure 1 As shown, the present invention includes a rotor 1 and a stator 2, wherein the rotor 1 includes a rotating shaft 402, a bearing 403, a split permanent magnet 102, and a rotor core pole 103;

[0057] The separated permanent magnet 102 of the rotor 1 is an isosceles trapezoidal permanent magnet excitation structure composed of three permanent magnets separated from a surface-mounted permanent magnet, wherein a full-width outer permanent magnet 102-1 is alternately arranged with the rotor core pole 103 to form an outer permanent magnet array of the rotor; two half-width and equal-height inner permanent magnets 102-2 rotate toward the inner surface of the rotor with the circumferential outer separation point of the surface-mounted permanent magnet as the circle to form an inner permanent magnet array of the rotor; the permanent magnet excitation magnetic field on the rotor and the permanent magnet excitation magnetic field on the stator are modulated by the stator teeth and the rotor core 101 respectively and then coupled with the armature winding 204, and electromechanical energy conversion is carried out in the air gap magnetic field based on the dual magnetic field modulation effect; only a single-layer air gap between the stator 2 and the rotor 1 is involved, and the motor has a compact topology structure.

[0058] like Figure 6 As shown, the stator permanent magnet 201 and the stator tooth top 202 form a stator alternating pole permanent magnet structure to assist in excitation and adjust the magnetic field distribution in the motor;

[0059] The rotor 1 adopts a split-type alternating-pole permanent magnet excitation. The permanent magnet structure has high excitation capability under the same permanent magnet dosage, and adjusts the air gap magnetic field distribution in the motor to reduce the harmonic distortion rate.

[0060] Among them, the stator and rotor permanent magnets can adopt hybrid permanent magnet excitation, the rotor permanent magnets are replaced by permanent magnets with higher remanence, and the stator permanent magnets are replaced by permanent magnets with lower remanence, forming a hybrid permanent magnet excitation structure, which reduces the manufacturing cost of the motor and avoids magnetic saturation of the rotor when running at high speed.

[0061] like Figure 7 As shown, the rotor 1 adopts a split-type alternating-pole permanent magnet excitation, wherein the radially magnetized surface-mounted permanent magnet based on the initial design of the motor is separated into three permanent magnets along its radial centerline and circumferential centerline, namely, an outer permanent magnet 102-1 of full width and two inner permanent magnets 102-2 of half width and equal height. The two inner permanent magnets 102-2 rotate toward the inner surface of the rotor with the circumferential outer separation point of the permanent magnet as the center point, forming a split-type permanent magnet 102 structure with the outer permanent magnet 102-1 in an isosceles trapezoidal structure. This permanent magnet structure has high excitation capability under the same permanent magnet dosage, optimizes the air gap magnetic field distribution in the motor, and reduces the harmonic distortion rate.

[0062] like Figure 9 As shown, the rotor 1 adopts a separated alternating-pole permanent magnet excitation, and the radially magnetized surface-mounted permanent magnet based on the initial design of the motor is separated into three permanent magnets along its radial center line and circumferential center line, namely, an outer permanent magnet 102-1 of full width and two inner permanent magnets 102-2 of half width and equal height. The two inner permanent magnets 102-2 rotate toward the inner surface of the rotor 1 with the circumferential outer separation point of the permanent magnet as the center point, forming an isosceles trapezoidal separated permanent magnet structure with the outer permanent magnet 102-1. The two inner permanent magnets 102-2 can be replaced by low magnetic energy product permanent magnets with lower remanence values ​​than the outer permanent magnets 102-1 to form a hybrid permanent magnet excitation structure, thereby reducing the air gap magnetic field harmonic distortion rate.

[0063] like Figure 10 、 Figure 11 As shown, the stator permanent magnet 201 and the stator tooth top 202 disclosed in the present invention form an alternating pole permanent magnet structure, which can also be evolved into two other structures: each stator permanent magnet 201 and its adjacent stator tooth top 202 form an alternating pole structure, which not only saves a large amount of permanent magnets, but also the stator tooth top 202 can be used as a modulation pole to adjust the air gap magnetic field; each stator tooth top 202 has several sub-teeth, and the stator permanent magnet 201 and the adjacent stator tooth top 202 form an alternating pole structure.

[0064] Finally, it should be understood that the embodiments described in the present invention are only used to illustrate the principles of the embodiments of the present invention; other variations may also fall within the scope of the present invention; therefore, as examples rather than limitations, alternative configurations of the embodiments of the present invention may be considered consistent with the teachings of the present invention; accordingly, the embodiments of the present invention are not limited to the embodiments explicitly introduced and described herein.

Claims

1. A split-type alternating-pole permanent magnet motor based on dual magnetic field modulation effect, characterized in that: It comprises a rotor (1) and a stator (2); The rotor (1) comprises a rotor core (101) and a plurality of separate permanent magnets (102) mounted on the rotor core (101); The stator (2) comprises a stator permanent magnet (201), a stator tooth top (202), a stator core (203) and an armature winding (204); The split permanent magnet (102) is a radially magnetized surface-mounted permanent magnet that is separated into three permanent magnets along its radial centerline and circumferential centerline, namely, an outer permanent magnet (102-1) of full width and two inner permanent magnets (102-2) of half width and equal height. The two inner permanent magnets (102-2) rotate toward the inner surface of the rotor (1) with the outer separation point of the surface-mounted permanent magnet as the center point. After rotation, the inner permanent magnets (102-2) can form a separated permanent magnet structure with the outer permanent magnet (102-1) in the form of an isosceles trapezoid, a rectangle, or a triangle-rectangle combination. The two inner permanent magnets (102-2) are arranged to form an optimized magnetic field concentration structure, and the excitation direction of the structure is the same as that of the outer permanent magnet (102-1); The separation point is radially spaced from the upper and lower surfaces of the surface-mounted permanent magnet by more than 1 / 4 of the height of the surface-mounted permanent magnet, and circumferentially spaced from the circumferential center line of the surface-mounted permanent magnet by more than 1 / 8 of the width of the surface-mounted permanent magnet; When the separation point is outside the circumference of the surface-mounted permanent magnet and the rotation angle of the inner permanent magnet (102-2) is less than 90 degrees, the separation-type permanent magnet (102) is an isosceles trapezoidal structure; When the separation point is outside the circumference of the surface-mounted permanent magnet and the rotation angle of the inner permanent magnet (102-2) is equal to 90 degrees, the separation-type permanent magnet (102) is a rectangular structure; When the separation point is not on the circumferential outer side of the surface-mounted permanent magnet and the rotation angle of the inner permanent magnet (102-2) is less than 90 degrees, the separation-type permanent magnet (102) is a triangle-rectangular structure.

2. A split-type alternating-pole permanent magnet motor based on dual magnetic field modulation effect according to claim 1, characterized in that: A rotor core pole (103) is connected between the outer permanent magnets (102-1) of two adjacent separated permanent magnets (102) and between the inner permanent magnet (102-2) and another inner permanent magnet (102-2) spaced apart.

3. The split-type alternating-pole permanent magnet motor based on the dual magnetic field modulation effect according to claim 1, characterized in that: A stator permanent magnet (201) is disposed between two adjacent stator tooth tops (202), and an alternating pole structure is formed by alternatingly arranging the stator tooth tops (202) and the stator permanent magnet (201); An armature winding (204) is installed on the other side of the stator permanent magnet (201).

4. The split-type alternating-pole permanent magnet motor based on the dual magnetic field modulation effect according to claim 1, characterized in that: A housing (401) is installed outside the stator (2), a rotating shaft hole is opened on the housing (401), a rotating shaft (402) is installed in the rotating shaft hole, and the rotating shaft (402) passes through the rotating shaft hole and is installed on the rotor (1).

5. The split-type alternating-pole permanent magnet motor based on the dual magnetic field modulation effect according to claim 4, characterized in that: A bearing (403) is installed in the rotating shaft hole and outside the rotating shaft (402).

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