Modular stator and preparation method thereof, and axial magnetic field permanent magnet motor

Abstract

The invention discloses a modular stator, a preparation method thereof and an axial magnetic field permanent magnet motor. The axial magnetic field permanent magnet motor comprises a modular stator, and rotors are arranged on the two axial sides of the modular stator respectively. The modularized stator comprises a plurality of skewed slot stator units which are spliced in the circumferential direction, each skewed slot stator unit comprises a skewed slot stator iron core and an armature winding coil wound on the skewed slot stator iron core, and each skewed slot stator iron core is provided with a right-angle wall and an oblique-angle wall which are opposite in the circumferential direction. The oblique angle wall gradually deviates from the central axis of the skewed slot stator core in the direction from the radial inner side to the radial outer side. By optimizing the appearance of the skewed slot stator iron core, the processing technology of the modular stator is simplified, stray loss is reduced, and the cogging torque and torque pulsation of the motor are reduced at the same time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor equipment, in particular to an axial magnetic field permanent magnet motor, and especially to a modular stator and a preparation method thereof. BACKGROUND

[0002] With the increasingly prominent energy and environmental problems, the gradually urgent demand of intelligent society, and the rapid development of electric drive technology, high-performance motor drive systems are paid more and more attention in today's society. Electric vehicle drive, robot servo drive, electric aircraft propulsion and other application occasions put forward higher requirements on the core indicators such as torque density and efficiency of motor systems. Permanent magnet synchronous motor has become the research focus of high-performance motor systems due to its high torque density, high efficiency, high design freedom, low vibration and noise and other advantages. Axial magnetic field permanent magnet motor has large air gap area, compact axial size and high torque density, and has natural adaptability under the constraint of flat shape. In particular, single-stator double-rotor axial magnetic field permanent magnet motor has extremely high torque density, and is an important research direction of high-performance electric drive occasions. Among them, the single-stator double-rotor axial magnetic field permanent magnet motor with two rotors axially opposite and permanent magnets of opposite magnetization polarity can adopt a yokeless stator structure, further reducing the weight and iron loss of the motor stator, and improving the torque density and efficiency of the motor. The stator core of the yokeless single-stator double-rotor axial magnetic field permanent magnet motor is composed of a plurality of independent modular stator core units. The modular stator structure utilizes product batch manufacturing and transportation, and is beneficial to improving the slot fill rate. However, the modular stator core unit has a symmetrical trapezoidal structure, and the two tangential end faces are both bevel structures, which are difficult to process and can easily cause excessive additional stray loss during processing. In addition, the single-stator double-rotor axial magnetic field permanent magnet motor has high air gap magnetic flux density and large harmonic content, resulting in high motor torque ripple. SUMMARY

[0003] The present application aims to provide a modular stator and a preparation method thereof, and an axial magnetic field permanent magnet motor, to solve at least one problem existing in the prior art.

[0004] To achieve the above-mentioned purpose, based on one aspect of the present application, a modular stator applied to an axial magnetic field permanent magnet motor is provided, which comprises a plurality of slotted stator units spliced in the circumferential direction; each slotted stator unit comprises a slotted stator core and an armature winding coil wound on the slotted stator core; each slotted stator core has a right-angle wall and an oblique-angle wall opposite in the circumferential direction; and the oblique-angle wall gradually deviates from the center axis of the slotted stator core in the direction from the radially inner side to the radially outer side.

[0005] In some embodiments, the right-angle wall and the oblique-angle wall of adjacent slotted stator cores remain parallel.

[0006] In some embodiments, each of the skew-slot stator core is formed by radially stacking a plurality of silicon steel sheets.

[0007] In some embodiments, a plurality of the skew-slot stator units are mechanically connected into one whole by at least one of an insulating material, a potting material and a retaining bracket.

[0008] In some embodiments, the armature winding coil is a concentrated winding structure.

[0009] To achieve the above-mentioned purpose, based on another aspect of the present application, a preparation method of a modular stator is provided, comprising:

[0010] Preparation of a skew-slot stator core, the skew-slot stator core has circumferentially opposite right-angle walls and skew-angle walls, the skew-angle walls gradually deviate from the central axis of the skew-slot stator core in the direction from the radially inner side to the radially outer side;

[0011] Winding an armature winding coil on the skew-slot stator core to form a skew-slot stator unit;

[0012] A plurality of the skew-slot stator units are circumferentially spliced to form one whole.

[0013] In some embodiments, the preparation method further comprises:

[0014] A plurality of the skew-slot stator units are mechanically connected into one whole by at least one of an insulating material, a potting material and a retaining bracket.

[0015] In some embodiments, the step of preparing the skew-slot stator core comprises:

[0016] Radially stacking a plurality of rectangular silicon steel sheets to form a primary structure;

[0017] Using a tool to limit a right-angle wall of the primary structure, and processing another right-angle wall of the primary structure to form a skew-angle wall.

[0018] To achieve the above-mentioned purpose, based on still another aspect of the present application, an axial magnetic field permanent magnet motor is provided, comprising the modular stator of any one of the above-mentioned embodiments, and a rotor is arranged on each axial side of the modular stator.

[0019] In some embodiments, each of the rotors comprises a rotor core and a plurality of rotor permanent magnets; a plurality of the rotor permanent magnets are installed on the side of the rotor core close to the modular stator; at least part of the rotor permanent magnets on at least one of the rotors is in a skew-pole structure; when the rotor permanent magnet is in a skew-pole structure, the inclination angle of the central axis of the rotor permanent magnet is consistent with the inclination angle of the central axis of the skew-slot stator core, and the inclination directions are the same.

[0020] Compared with the prior art, the modular stator and the preparation method thereof and the axial magnetic field permanent magnet motor provided by the application have at least the following beneficial effects:

[0021] In the modular stator provided by the application, a plurality of skew-slot stator units are spliced in the circumferential direction; each skew-slot stator unit comprises a skew-slot stator core and an armature winding coil wound on the skew-slot stator core; each skew-slot stator core has a circumferentially opposite right-angle wall and an oblique-angle wall; and the oblique-angle wall gradually deviates from the central axis of the skew-slot stator core in the direction of pointing from the radially inner side to the radially outer side. In this way, the profile of the stator core is optimized, the processing technology of the modular stator is simplified, the tooling is also simplified, the stray loss in the processing process is reduced, and the cogging torque and torque ripple are inhibited.

[0022] Since the preparation method of the modular stator and the axial magnetic field permanent magnet motor provided by the application belong to the same inventive concept as the modular stator provided by the application, the preparation method of the modular stator and the axial magnetic field permanent magnet motor provided by the application have at least all the beneficial effects of the modular stator provided by the application, and thus the beneficial effects of the preparation method of the modular stator and the axial magnetic field permanent magnet motor provided by the application will not be described one by one here. BRIEF DESCRIPTION OF DRAWINGS

[0023] The accompanying drawings serve to better understand the application and do not constitute an improper limitation on the application.

[0024] Figure 1 The exploded structural schematic diagram of the axial magnetic field permanent magnet motor provided by the embodiment of the application;

[0025] Figure 2 The two-dimensional plane schematic diagram of a single skew-slot stator core provided by the embodiment of the application;

[0026] Figure 3 The two-dimensional plane schematic diagram of two circumferentially adjacent rotor permanent magnets adopting an oblique pole structure provided by the embodiment of the application;

[0027] Figure 4 The two-dimensional plane schematic diagram of a rotor permanent magnet not adopting an oblique pole structure provided by the embodiment of the application;

[0028] Figure 5 The load torque curve diagram of the embodiment and the comparative embodiment of the application, in which the horizontal coordinate is the rotor position (i.e. the electrical angle, unit °) and the vertical coordinate is the motor torque unit.

[0029] Explanation of reference signs:

[0030] 1 - modular stator, 2 - first rotor, 3 - second rotor, 11 - skewed stator core, 111 - right angle wall, 113 - bevel wall, 11a - radial inner side, 11b - radial outer side, 101 - center axis of skewed stator core, 102 - center ray of modular stator, 12 - armature winding coil, 21 - first rotor permanent magnet, 22 - first rotor core, 201 - center axis of first rotor permanent magnet, 202 - center ray of first rotor, 31 - second permanent magnet, 32 - second rotor core, a - angle of center axis of skewed stator core or bevel of permanent magnet inclined circumferentially, b - included angle of right angle wall and bevel wall. DETAILED DESCRIPTION

[0031] The above objects and advantages of the present application are achieved by the following embodiments. Other advantages of the present application will be readily appreciated by those skilled in the art from the following detailed description, when taken in connection with the drawings, wherein:

[0032] In addition, each of the embodiments described below has one or more technical features. However, this does not mean that all technical features in any embodiment must be implemented simultaneously, or that only one or more technical features in different embodiments can be implemented separately. In other words, under the premise of implementation, those skilled in the art can selectively implement some or all of the technical features in any embodiment, or selectively implement a combination of some or all of the technical features in multiple embodiments, according to the disclosure of the present application, based on design specifications or actual needs, thereby increasing the flexibility of the implementation of the present application.

[0033] As used in this specification, the singular forms "a," "an" and "the" include plural referents unless the context clearly dictates otherwise. As used in this specification, the term "or" is generally employed in its sense of "and / or" unless the content clearly dictates otherwise, and the term "have" or "has" is generally employed in its sense of "have or has at least one" or "having or having at least one." The term "connected" or "coupled" is used broadly and encompass both direct and indirect connections, as well as fixed and removable connections. It is to be further understood that the terms "connected" and "coupled" and the like are used herein to refer to one element or component (including any intervening elements or components) that is either directly connected or coupled to another element or component or that is so associated with another element or component that the other element or component, so associated, can be said to be in contact with, or connected or coupled to, the first element or component. The terms "first," "second," and other such relative terms are used only to distinguish one element or action from another, but do not otherwise limit the elements or actions, nor any of the uses thereof, described or claimed herein. It is to be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," "circumferential," and the like, merely describe the orientation or position of an element if the specification so states and are not intended to limit the scope of the application to any specific spatial or temporal arrangement of elements. Unless otherwise defined, all terms used herein have the same meaning as they would to one of ordinary skill in the art in the field of the application.

[0034] For the purpose of clarity, the present application will be further described with reference to the accompanying drawings. It is to be understood that the drawings are not to scale and are merely intended to be illustrative and not limiting of the present application.

[0035] The purpose of the present application is to provide a modular stator and a preparation method thereof, and an axial magnetic field permanent magnet motor, at least to solve the problems of large machining difficulty and large stray loss in the machining process of the existing modular stator core of the axial magnetic field permanent magnet motor. It should be noted that the axial magnetic field permanent magnet motor provided by the present application includes but is not limited to a single-stator double-rotor basic configuration, and in other cases, it can also be extended to a multi-stator configuration, and one rotor is arranged on each axial side of each stator.

[0036] The following is described in conjunction with the accompanying drawings.

[0037] Figure 1 The exploded structural schematic diagram of the axial magnetic field permanent magnet motor provided by the present application is shown in FIG. 1. As shown in FIG. 1, the axial magnetic field permanent magnet motor provided by the present application includes a stator 1 and a rotor 2. Figure 1As shown, the axial magnetic field permanent magnet motor provided by the embodiment of the present application comprises a modular stator 1, one rotor (reference numeral 2 and 3) is arranged on each axial side of the modular stator 1, each rotor comprises a rotor core and a plurality of rotor permanent magnets; the plurality of rotor permanent magnets are installed on the rotor core on the side close to the modular stator 1.

[0038] In the embodiment of the present application, the rotor on each axial side of the modular stator 1 is defined as a first rotor 2 and a second rotor 3, the rotor core of the first rotor 2 is a first rotor core 22, the rotor permanent magnet of the first rotor 2 is a first rotor permanent magnet 21, the rotor core of the second rotor 3 is a second rotor core 32, and the rotor permanent magnet of the second rotor 3 is a second rotor permanent magnet 31.

[0039] The plurality of first rotor permanent magnets 21 are installed on the first rotor core 22 on the side close to the modular stator 1, that is, on the side close to the air gap; the plurality of first rotor permanent magnets 21 are sequentially arranged along the circumference of the first rotor core 22, and the polarity (N or S) alternates. Similarly, the plurality of second rotor permanent magnets 31 are installed on the second rotor core 32 on the side close to the modular stator 1, that is, on the side close to the air gap; the plurality of second rotor permanent magnets 31 are sequentially arranged along the circumference of the second rotor core 32, and the polarity (N or S) alternates.

[0040] In the embodiment of the present application, the magnetic pole directions of the first rotor permanent magnet 21 and the second rotor permanent magnet 31 are both along the axial direction, the pole pairs of the first rotor permanent magnet 21 and the second rotor permanent magnet 31 are equal, and the first rotor permanent magnet 21 and the second rotor permanent magnet 31 axially face each other one by one, but the magnetic pole directions of the two corresponding permanent magnets in the axial facing relationship are opposite, for example, the magnetic pole of the first rotor permanent magnet 21 in the axial facing relationship is N pole, and the magnetic pole of the corresponding second rotor permanent magnet 31 is S pole. In addition, the first rotor permanent magnet 21 and the second rotor permanent magnet 31 can have the same shape and size, or different shape and size.

[0041] In the embodiment of the present application, the axial magnetic field permanent magnet motor only comprises one modular stator 1 and two rotors. However, in other embodiments, the axial magnetic field permanent magnet motor can further comprise more modular stators 1. Whether the modular stator 1 is one or more, one rotor is arranged on each axial side of the modular stator 1.

[0042] As an example, the axial magnetic field permanent magnet motor adopts stator skew slot, permanent magnet skew pole, single stator double rotor without yoke, and is formed into a double air gap circumferential magnetic field permanent magnet motor structure.

[0043] As an example, the axial magnetic field permanent magnet motor is a three-phase stator 18 slot, rotor 20 pole structure, that is, 18 slot 20 pole matching, which belongs to fractional slot winding, but in fact can not be limited thereto.

[0044] The number of phases of the axial magnetic field permanent magnet motor is not particularly limited in the embodiments of the present application. In general, the axial magnetic field permanent magnet motor of the present application is applicable to different number of phases, and the axial magnetic field permanent magnet motor can use the same or different number of stator and rotor poles and slots.

[0045] The axial magnetic field permanent magnet motor of the embodiments of the present application can load sinusoidal current, and through electromagnetic induction and interaction with the rotor permanent magnet magnetic field, a continuous rotating torque is generated.

[0046] With reference to Figure 1 The embodiments of the present application also provide a modular stator 1, which includes a plurality of circumferentially spliced skew-slot stator units; each of the skew-slot stator units includes a skew-slot stator core 11 and an armature winding coil 12 wound on the skew-slot stator core 11. It should be noted that the plurality of skew-slot stator units have the same structure and are independent of each other, and since a modular design is adopted, each skew-slot stator core 11 adopts a yoke-free design. The plurality of skew-slot stator cores 11 have the same shape and size, and they are circumferentially spliced to form a complete stator core without yoke connection.

[0047] Figure 2 A two-dimensional plane schematic diagram of the skew-slot stator core 11 provided in the embodiments of the present application is provided to describe the orthographic projection of the skew-slot stator core 11 in the axial direction perpendicular to the modular stator 1. As shown in Figure 2 each of the skew-slot stator cores 11 has circumferentially opposite right-angle walls 111 and skew-angle walls 113, wherein the skew-angle walls 113 gradually deviate from the central axis 101 of the skew-slot stator core 11 in the direction from the radial inner side 11a to the radial outer side 11b. In other words, along the radial direction from the inside to the outside, the skew-angle walls 113 are inclined in the direction away from the right-angle walls 111, so that the width of the lower bottom wall corresponding to the radial inner side 11a on the skew-slot stator core 11 in the circumferential direction is smaller than the width of the upper bottom wall corresponding to the radial outer side 11b in the circumferential direction. Therefore, each of the skew-slot stator cores 11 has a right-angle trapezoidal structure, which is different from the symmetrical trapezoidal structure of the conventional modular stator core.

[0048] In this article, the center axis 101 of the skew-slot stator core 11 refers to the connection between the midpoints of the upper bottom wall and the lower bottom wall of the skew-slot stator core 11. The center axis 101 of the skew-slot stator core 11 does not pass through the center axis of the entire modular stator 1 and does not intersect the center axis of the modular stator 1. Therefore, the center axis 101 of the skew-slot stator core 11 is inclined by a predetermined angle a in the circumferential direction compared to the center axis 102 of the modular stator 1. Here, the center axis 102 of the modular stator 1 passes through the center of the modular stator 1 and is perpendicular to the center axis of the modular stator 1, and the center axis 102 corresponds to the diameter direction of the modular stator 1. Since the value of the predetermined angle a needs to be determined according to factors such as motor specifications / type, etc., the present application does not limit this. And the inclination angle (i.e. the included angle β) of the oblique wall 113 relative to the right-angle wall 111 satisfies: tan β = 2*tan a.

[0049] In this way, by tilting the center axis 101 of the skew-slot stator core 11 by a fixed angle in the circumferential direction compared to the center axis 102 of the modular stator, the present application ensures that one circumferential end face of the skew-slot stator core 11 has a right-angle edge shape and the other circumferential end face has an oblique edge shape, and finally forms a right-angle trapezoidal structure, which is different from the symmetric trapezoidal structure of the traditional modular stator core unit. This structural design of the skew-slot stator core 11 is beneficial to suppressing cogging torque and torque ripple, and more importantly, the processing technology of the skew-slot stator core 11 can be optimized, the number of circumferential end faces that need to be precisely machined to an oblique edge is reduced from 2 to 1, and a simpler processing tool can be used, thereby simplifying the processing process and processing cost, reducing stray loss in the processing process, and helping to improve motor efficiency.

[0050] In some embodiments, the right-angle wall 111 and the oblique wall 113 of adjacent skew-slot stator cores 11 maintain a parallel relationship. In this way, it is ensured that any two adjacent skew-slot stator units can be attached to form an integrated structure in the circumferential direction.

[0051] In some embodiments, a plurality of skew-slot stator units are mechanically connected into a whole by at least one of an insulating material, a potting material, and a retaining bracket.

[0052] The insulating material includes but is not limited to insulating glue and insulating paint, and can also be other insulating materials commonly used in the art. After the insulating material is provided, the armature winding coil 12 is wound on the skew-slot stator core 11, so that the adjacent skew-slot stator units are kept insulated from each other and the mechanical fixation of the modular stator 1 is achieved.

[0053] The potting material includes but is not limited to epoxy resin, and the specific material selection needs to be determined according to the process requirements and material properties. The potting material can fix the modular stator 1, provide insulation protection, improve stability, and improve heat conduction and heat dissipation.

[0054] The retaining bracket can mechanically fix the chute stator unit through various measures such as interference fit, male-female fit, keyway fit, and latch fit, and the specific implementation mode can be realized by a person skilled in the art based on conventional knowledge.

[0055] In addition, the application does not particularly limit the processing mode of the chute stator core 11, especially the processing mode of the bevel wall 113.

[0056] In some embodiments, at least one of laser cutting and wire cutting can be used for processing to obtain the chute stator core 11 with the required shape. During the processing, the positioning of the tooling can be used to assist in finishing to ensure the processing accuracy.

[0057] As an example, a certain number of rectangular silicon steel sheets are prepared, and several rectangular silicon steel sheets are stacked in the radial direction to form a primary structure. Then, the right-angle wall 111 of the primary structure is positioned by the tooling, and the other right-angle wall of the primary structure is processed, so that the bevel wall 113 is formed, and the chute stator core 11 with the required shape is obtained.

[0058] Therefore, in some embodiments, a plurality of rectangular silicon steel sheets can be stacked in the radial direction to form a primary structure, and then finished to form the chute stator core 11 with the right-angle wall 111 and the bevel wall 113. This process avoids the complexity of single-piece processing of silicon steel sheets and improves production efficiency.

[0059] After the chute stator core 11 is completed and formed, the armature winding coil 12 can be nested respectively to form a chute stator unit, and the armature winding coil 12 can be nested before or after being spliced in the circumferential direction, which is not limited.

[0060] In some embodiments, the armature winding coil 12 adopts a concentrated winding structure. In this way, the length of the winding end is reduced, the copper loss of the coil is reduced, and the motor power density is improved.

[0061] Figure 3 A two-dimensional plane schematic diagram of the rotor permanent magnet with a skew pole structure is provided for the embodiments of the application, which describes the orthogonal projection of the rotor permanent magnet in the axial direction perpendicular to the rotor. Taking the first rotor 2 as an example, as shown in Figure 3As shown, in some embodiments, the first rotor permanent magnets 21 are arranged in a skew structure on the first rotor core 22, that is, all the first rotor permanent magnets 21 are arranged in a circumferential direction on the first rotor core 22, and at this time, the central axis 201 of each first rotor permanent magnet 21 is inclined by a predetermined angle a compared to the central ray 202 of the first rotor 2.

[0062] If applied to the second rotor 3, the second rotor permanent magnets 31 are arranged in a skew structure on the second rotor core 32, so that the central axis of the second rotor permanent magnet 31 is inclined by a predetermined angle a compared to the central ray of the second rotor 3. Preferably, all the second rotor permanent magnets 31 are arranged in a skew structure on the second rotor core 32.

[0063] In fact, at least part of the rotor permanent magnets on at least one of the rotors can be arranged in a skew structure, and it is only necessary to ensure that the inclination angle of the central axis (indicated by 201) of the rotor permanent magnet is consistent with the inclination angle of the central axis (indicated by 101) of the skew-slot stator core 11, and the inclination directions are the same. Herein, the central axis of the rotor permanent magnet refers to the connecting line between the radial inner and outer circumferences of the rotor permanent magnet. If a skew structure is adopted, the central axis of the rotor permanent magnet does not pass through the central axis of the rotor, and does not intersect the central axis of the rotor.

[0064] Figure 4 A two-dimensional planar schematic diagram of the rotor permanent magnet provided by the embodiments of the present application does not adopt a skew structure. Taking the first rotor 2 as an example for further description, as shown in Figure 4 As shown, in some embodiments, all the first rotor permanent magnets 21 do not adopt a skew structure on the first rotor core 22, and at this time, the central ray 202 of the first rotor 2 is the central axis of the first rotor permanent magnet 21, so that the first rotor permanent magnet 21 is arranged in a circumferential direction about the central ray 202.

[0065] If applied to the second rotor 3, all the second rotor permanent magnets 31 do not adopt a skew structure on the second rotor core 32, so that the second rotor permanent magnet 31 is arranged in a circumferential direction about the central ray 202 of the second rotor 3.

[0066] As an example, the first rotor permanent magnet 21 and the second rotor permanent magnet 31 do not adopt a skew structure.

[0067] As an example, one of the first rotor permanent magnet 21 and the second rotor permanent magnet 31 adopts a skew structure, and the other does not adopt a skew structure.

[0068] As an example, the first rotor permanent magnet 21 and the second rotor permanent magnet 31 both adopt a skew structure.

[0069] Further, in order to avoid the average torque reduction caused by the stator skew (i.e. the skew stator core 1 is in a right trapezoidal structure), in the embodiment of the present application, at least part of the rotor permanent magnets on at least one rotor are arranged in a skew pole structure; when the rotor permanent magnets adopt the skew pole structure, they present an asymmetric fan-shaped structure that is inclined in the circumferential direction, i.e. the rotor permanent magnet skew pole structure. Therefore, for the same rotor, part or all of the rotor permanent magnets can be in the skew pole structure (i.e. the asymmetric fan-shaped structure).

[0070] Specifically, in the embodiment of the present application, the permanent magnets on the rotors on the two axial sides of the modular stator 1 all adopt the skew pole structure, which has a better effect.

[0071] Therefore, while the skew stator core 11 proposed in the embodiment of the present application is adopted, the skew pole permanent magnet structure shown in Figure 3 can be adopted, and the center axis inclination angle of the skew pole permanent magnet is consistent with the center axis inclination angle of the skew stator core 11, i.e. the skew stator and the skew pole rotor are synchronous, thereby avoiding the average torque reduction problem caused by the stator skew. It should be understood that if any one rotor adopts the non-skew pole permanent magnet structure shown in Figure 4 , although the stator skew structure can suppress the cogging torque and torque ripple, the average torque is reduced. Therefore, the embodiment of the present application significantly improves the average torque reduction problem caused by the stator skew by cooperatively adopting the stator skew structure and the rotor permanent magnet skew pole design.

[0072] Then, as shown in Figure 5 , the load torque of the embodiment of the present application is basically consistent with that of the comparative embodiment (the traditional modular non-skew stator core and the non-skew pole permanent magnet structure), which proves that the average torque loss caused by the stator skew is effectively compensated by the cooperative effect of the stator skew structure and the rotor permanent magnet skew pole. As can be understood by those skilled in the art, the motor torque per unit value is usually based on the rated torque and is defined as the ratio of the actual torque to the rated torque, so the motor performance is evaluated by the motor torque per unit value, and the load torque loss is illustrated

[0073] It should be pointed out that theoretically, the skew only needs to be applied to either side of the stator and rotor, i.e. the effect of suppressing the cogging torque and torque ripple can be achieved, and the permanent magnet skew pole technology can also effectively suppress the cogging torque, but the average torque is also reduced synchronously. In view of the contradiction between the cogging torque / torque ripple suppression and the average torque maintenance, based on the proposed modular skew stator structure, the rotor skew pole structure is further matched, i.e. the stator slot and the rotor permanent magnet pole are synchronously inclined, and the center axes of the two remain parallel, thereby achieving the average torque maintenance. In this way, the processing technology of the modular stator core can be simplified, and the average torque sacrifice problem caused by the stator skew can be avoided.

[0074] Based on the same inventive concept, the application further provides a preparation method of the modular stator, comprising:

[0075] The skew-slot stator core 11 is prepared to have circumferentially opposite right-angle walls 111 and skew-angle walls 113, the skew-angle walls 113 gradually deviate from the central axis 101 of the skew-slot stator core 11 in a direction from the radially inner side 11a to the radially outer side 11b;

[0076] The armature winding coil 12 is wound on the skew-slot stator core 11 to form a skew-slot stator unit;

[0077] The skew-slot stator units are circumferentially spliced to form an integral whole.

[0078] In some embodiments, the preparation method further comprises:

[0079] The skew-slot stator units are mechanically connected to form an integral whole by using at least one of the insulating material, the potting material and the retaining bracket.

[0080] In some embodiments, the step of preparing the skew-slot stator core 11 comprises:

[0081] The primary structure is formed by radially stacking a plurality of rectangular silicon steel sheets;

[0082] The straight-angle wall 111 of the primary structure is limited by a tool, and the other straight-angle wall of the primary structure is processed to form the skew-angle wall 113.

[0083] Finally, it should be noted that the shape and size of the rotor and the modular stator 1 of the application can be changed, and the pole pair number, magnetization method, block number, permanent magnet material of the rotor permanent magnet, and the phase number, slot number, core shape, winding configuration of the modular stator 1 can be flexibly designed according to actual needs, in addition, a plurality of silicon steel sheets can be cut or stamped into the required shape, including but not limited to rectangular silicon steel sheets, and the circumferential side of all silicon steel sheets is positioned by a tool to ensure a right-angle edge, then a plurality of silicon steel sheets are stacked in the radial direction, which can constitute a skew-slot stator core 11 without a yoke, so that the skew-slot stator core 11 presents an asymmetric skew-slot structure.

[0084] The technical solution provided by the application has at least the following advantages:

[0085] 1) By designing the skew-slot stator core 11 as a right-angle trapezoidal structure, the processing tool is simplified, the number of finish machining end faces is reduced, the stray loss caused by finish machining is reduced, and since the skew-slot stator core 11 adopts a structure connected without a yoke part, batch processing production is easy, and the slot fill factor and core utilization rate are also improved;

[0086] 2) The stator skew structure is realized by the skew stator core 11, which is beneficial to inhibit the motor tooth slot torque and torque ripple. On the basis of the skew stator core 11, the skew pole structure is implemented on the rotor permanent magnet, and the stator skew and the rotor permanent magnet skew pole are kept synchronous, so that the average torque sacrifice caused by the stator skew can be avoided, that is, the design breaks through the inherent technical contradiction that the skew needs to compromise between harmonic suppression and torque loss;

[0087] 3) The armature winding coil 12 can adopt a concentrated armature winding structure, which reduces the winding end length, reduces the coil copper loss, improves the motor torque density, and the concentrated winding can be directly embedded on the modular stator core, simplifies the embedding process, and improves the slot fill rate. The motor has strong applicability, and the number of motor phases, slot pole number matching, core material and permanent magnet material can be flexibly selected.

[0088] Although the present application is disclosed as above, it is not limited thereto. Those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the present application specification and its equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A modular stator for use in an axial magnetic field permanent magnet motor, characterized in that, It includes several circumferentially spliced ​​skewed stator units; each skewed stator unit includes a skewed stator core and an armature winding coil wound on the skewed stator core; each skewed stator core has circumferentially opposite right-angled walls and oblique-angled walls; the oblique-angled walls gradually deviate from the central axis of the skewed stator core in a direction from the radially inner side to the radially outer side.

2. The modular stator according to claim 1, characterized in that, The right-angled walls and the beveled walls of adjacent skewed stator cores remain parallel.

3. The modular stator according to claim 1, characterized in that, Each of the aforementioned skewed stator cores is formed by stacking multiple silicon steel sheets radially.

4. The modular stator according to claim 1, characterized in that, Several of the skewed stator units are mechanically connected into a whole by at least one of an insulating material, a potting material, and a retaining bracket.

5. The modular stator according to claim 1, characterized in that, The armature winding coil has a concentrated winding structure.

6. A method for fabricating a modular stator, characterized in that, include: A skewed stator core is prepared such that the skewed stator core has circumferentially opposite right-angled walls and chamfered walls, and the chamfered walls gradually deviate from the central axis of the skewed stator core in the direction from the radial inner side to the radial outer side. An armature winding coil is wound on the skewed stator core to form a skewed stator unit; Several of the aforementioned inclined slot stator units are spliced ​​together circumferentially to form a whole.

7. The method for preparing a modular stator according to claim 6, characterized in that, Also includes: The plurality of said inclined slot stator units are mechanically connected into a whole using at least one of insulating material, potting material and retaining bracket.

8. The method for preparing a modular stator according to claim 6, characterized in that, The steps for preparing the skewed slot stator core include: Several rectangular silicon steel sheets are stacked radially to form a primary structure; The tooling is used to limit the right-angled wall of the primary structure, and the other right-angled wall of the primary structure is processed to form an oblique wall.

9. An axial magnetic field permanent magnet motor, characterized in that, The modular stator as described in any one of claims 1-5 is provided with a rotor on each of its axial sides.

10. The axial magnetic field permanent magnet motor according to claim 9, characterized in that, Each rotor includes a rotor core and a plurality of rotor permanent magnets; the plurality of rotor permanent magnets are mounted on the rotor core on one side near the modular stator; at least a portion of the rotor permanent magnets on at least one rotor are of skewed pole structure; when the rotor permanent magnet is of skewed pole structure, the tilt angle of the central axis of the rotor permanent magnet is consistent with the tilt angle of the central axis of the skewed stator core, and the tilt directions are the same.

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