Permanent magnet synchronous motor and method for manufacturing stator of permanent magnet synchronous motor

Abstract

The present disclosure relates to a permanent magnet synchronous motor. The permanent magnet synchronous motor comprises a rotor and a stator; the rotor comprises a first permanent magnet and second permanent magnets; the first permanent magnet is configured as a cylinder and is integrally formed; ten spacing grooves are formed in the first permanent magnet in the circumferential direction; the second permanent magnets are arranged in the spacing grooves; the rotor is provided with ten alternating magnetic poles; and the spacing grooves are used for accommodating a magnetic field applying device during orientation and magnetizing, so that the first permanent magnet obtains permanent magnetism; the stator is constructed as a hollow cylinder; twelve groove portions are arranged in the circumferential direction of the stator; the groove portions are used for accommodating a stator winding; and a tooth portion is formed between every two adjacent groove portions, a tooth shoe is formed at an end of the tooth portion, and a notch is formed between every two adjacent tooth shoes. Compared with traditional permanent magnet synchronous motors, the present permanent magnet synchronous motor involves lower manufacturing costs and has high power and energy efficiency levels. In addition, the present disclosure further relates to a method for manufacturing a stator of a permanent magnet synchronous motor.

Description

Permanent magnet synchronous motor and method for manufacturing a stator of the same

[0001] This application claims priority to Chinese Patent Application No. 202410163746.8 and No. 202420282608.7 filed on February 5, 2024, and the contents of the above-mentioned Chinese patent application disclosures are hereby incorporated by reference in their entirety as part of this application. Technical Field

[0002] The present disclosure relates to a permanent magnet synchronous motor and a method for manufacturing a stator of the permanent magnet synchronous motor. Background Art

[0003] A permanent magnet synchronous motor consists of a rotor and a stator. In some cases, the rotor consists of a magnetizer and a permanent magnet. The magnetizer is usually made of a stack of stamped silicon steel sheets. When non-oriented silicon steel sheets are used, the magnetization depth of the magnetizer is not deep enough. When oriented silicon steel sheets are used, the magnetization of the magnetizer will be uneven due to the specific orientation of the silicon steel sheets. In addition, the magnetizer itself is non-magnetic, which results in a waste of rotor space for the magnetizer, resulting in insufficient utilization of the rotor space and an inability to maximize the magnetic flux of the rotor. Permanent magnets can be attached to the surface of the magnetizer or embedded inside the magnetizer. In order to obtain greater magnetism and magnetic flux, permanent magnets are usually made of rare earth materials, such as neodymium iron boron. Rare earth materials are very expensive, so the cost of such a rotor is very high, and the diameter of a rotor with such a permanent magnet is not suitable for being designed too large.

[0004] To increase motor power, given a given rotor diameter and magnetic flux, the common approach is to increase the number of coils in the stator, for example by increasing the stator's cross-sectional area and slot fill ratio. This leads to higher copper and silicon steel sheet usage, resulting in higher stator costs.

[0005] In order to reduce the cost of permanent magnet synchronous motors and at the same time improve the efficiency of permanent magnet synchronous motors and make them comply with the energy efficiency levels promoted by the country, it is necessary to design a new type of permanent magnet synchronous motor.

[0006] Summary of the Invention

[0007] The present disclosure provides a permanent magnet synchronous motor, wherein the permanent magnet includes a rotor and a stator, wherein the rotor includes a first permanent magnet and a second permanent magnet, the first permanent magnet is constructed as a cylinder and is integrally formed, ten spacing slots are arranged in the circumferential direction inside the first permanent magnet, the second permanent magnet is arranged in the spacing slots, and the rotor has ten alternating magnetic poles, wherein the spacing slots are used to accommodate a magnetic field application device during the orientation and magnetization process so that the first permanent magnet obtains permanent magnetism, wherein the stator is constructed as a hollow cylinder, and twelve slots are arranged in the circumferential direction of the stator, the slots are used to accommodate stator windings, a tooth portion is formed between two adjacent slot portions, a tooth shoe is formed at the end of the tooth portion, and a slot is formed between adjacent tooth shoes.

[0008] In an embodiment according to the present disclosure, the first permanent magnet is made of plastic ferrite.

[0009] In an embodiment according to the present disclosure, the second permanent magnet is made of one or more of ferrite, neodymium iron boron, samarium iron nitrogen, and samarium cobalt.

[0010] In an embodiment according to the present disclosure, a ratio of an outer diameter to an inner diameter of the stator is in a range of 1.34 to 1.53.

[0011] In an embodiment of the present disclosure, the stator is divided into a plurality of stator sub-sections along the center lines of the slots, each stator sub-section has one tooth portion, and the cross section of the stator sub-section is an arc-shaped I-section.

[0012] In an embodiment according to the present disclosure, a width of the notch is in the range of 0.6 to 2 mm.

[0013] In an embodiment according to the present disclosure, a ratio of an outer diameter arc length of the stator sub-portion to an arc length of the tooth shoe is in a range of 1.42 to 1.60.

[0014] In an embodiment according to the present disclosure, a ratio of an inter-pole arc length between adjacent poles of the rotor to an outer diameter arc length between adjacent slot portions of the stator is in a range of 0.77 to 0.90.

[0015] In an embodiment according to the present disclosure, a ratio of an arc length of a tooth shoe of the stator to an arc length between poles of adjacent poles of the rotor is in a range of 0.78 to 0.81.

[0016] In an embodiment according to the present disclosure, the groove portion is designed as a pear-shaped groove or a flat-bottomed groove.

[0017] The present disclosure also provides a method for manufacturing the stator of the motor in the above embodiment, wherein the stator is divided into a plurality of stator sub-sections along the center lines of each of the slot portions, each stator sub-section has a tooth portion, and the cross-section of the stator sub-section is an I-shape with a curvature; the method comprises: arranging the stator sub-sections in a straight line; arranging stator conductors between the stator sub-sections; and connecting the stator sub-sections into the stator. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] To more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some exemplary embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0019] FIG1 shows a schematic cross-sectional view of a permanent magnet synchronous motor according to an embodiment of the present disclosure;

[0020] FIG2 shows an exploded perspective view of a rotor of a permanent magnet synchronous motor according to an embodiment of the present disclosure;

[0021] FIG3 shows a schematic cross-sectional view of a stator of a permanent magnet synchronous motor according to an embodiment of the present disclosure;

[0022] FIG4 shows a schematic cross-sectional view of a rotor of a permanent magnet synchronous motor according to an embodiment of the present disclosure;

[0023] FIG5 shows a schematic diagram of a magnetic circuit of a rotor of a permanent magnet synchronous motor according to an embodiment of the present disclosure;

[0024] FIG6 shows a partial schematic diagram of a magnetic circuit of a permanent magnet synchronous motor according to an embodiment of the present disclosure;

[0025] FIG7 shows a schematic diagram of stator subsections arranged in line according to an embodiment of the present disclosure;

[0026] FIG8 shows a schematic diagram of a linearly arranged stator subsection after arranging the stator conductors according to an embodiment of the present disclosure;

[0027] FIG9 shows a schematic diagram of a stator formed by joining stator subsections according to an embodiment of the present disclosure;

[0028] 10 is a perspective view of a terminal of a stator of a motor according to an embodiment of the present disclosure;

[0029] FIG11 is a six-view diagram of a terminal of a stator of a motor according to an embodiment of the present disclosure;

[0030] 12 is a top view of a wire slot portion of a terminal of a stator of a motor according to an embodiment of the present disclosure;

[0031] 13A and 13B are respectively a rear view and a top view of the straight bar stator of the motor in a straight line state according to an embodiment of the present disclosure;

[0032] 14 is a perspective view of a portion of a straight bar stator of a motor in accordance with an embodiment of the present disclosure in a straight line state;

[0033] FIG15A is a top view of a stator unit of a straight stator of a motor according to an embodiment of the present disclosure;

[0034] FIG15B is a top view of a terminal according to the present disclosure, and illustrates a wire guide direction;

[0035] FIG. 16 is a schematic diagram showing a process of fixing the end of the magnet wire to the terminal. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the technical solution of the present disclosure clearer, the technical solution of the embodiment of the present disclosure will be clearly and completely described below in conjunction with the drawings of the specific embodiments of the present disclosure. The same figure marks in the drawings represent the same parts. It should be noted that the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0037] Compared to the embodiments shown in the drawings, feasible embodiments within the scope of protection of the present disclosure may have fewer components, additional components not shown in the drawings, different components, differently arranged components, or differently connected components, etc. In addition, two or more components in the drawings may be implemented in a single component, or a single component shown in the drawings may be implemented as multiple separate components.

[0038] FIG1 shows a schematic cross-sectional view of a permanent magnet synchronous motor 100 according to an embodiment of the present disclosure. The permanent magnet synchronous motor 100 includes a rotor 110 and a stator 120. The rotor 110 has five pairs of magnetic poles (ten poles) and provides a constant magnetic field. Stator windings are arranged in the slots of the stator 120, and twelve slots are provided in the present disclosure. The stator windings are applied with three-phase alternating current or more-phase alternating current to generate a rotating magnetic field. The rotating magnetic field of the stator interacts with the magnetic field of the rotor and generates torque on the rotor and causes the rotor to rotate at a synchronous speed.

[0039] When the motor size or stator diameter is constant, in order to improve the power and torque of the motor, the number of rotor poles and the number of stator slots can be increased. However, the number of rotor poles and the number of stator slots cannot be increased indefinitely. The optimal motor power and torque correspond to a specific number of rotor poles, the number of stator slots, and the ratio of the number of stator slots to the number of rotor poles. For example, when the number of rotor poles is too large or the ratio of the number of stator slots to the number of rotor poles is too small, the surface area of ​​each rotor pole is too small and will negatively affect the back electromotive force and the motor torque. When the number of stator slots is too large, the space of each stator slot will be too small and the number of coil turns will be reduced. This will also negatively affect the back electromotive force and the motor torque. According to the experience of the inventors of the present disclosure, when the stator diameter is less than or equal to 175 mm, the permanent magnet synchronous motor 100 adopts a ten-pole twelve-slot design to achieve optimal performance.

[0040] The rotor 110 includes a first permanent magnet 111 and a second permanent magnet 112. FIG2 shows an exploded perspective view of the rotor 110 of a permanent magnet synchronous motor according to an embodiment of the present disclosure. FIG2 more clearly illustrates the shape, structure, and assembly relationship of the first permanent magnet 111 and the second permanent magnet 112. The first permanent magnet 111 is constructed as a cylinder and is integrally formed. In the present disclosure, the first permanent magnet 111 being constructed as a cylinder is particularly understood to mean that the outer contour of the first permanent magnet 111 is a cylinder. In the present disclosure, the first permanent magnet 111 being constructed as a cylinder is particularly understood to mean that the outer contour of the first permanent magnet 111 is a cylinder. In an embodiment of the present disclosure, the outer circumferential surface of the first permanent magnet 111 can be, for example, a closed surface to provide greater structural strength. Ten spacing slots 113 are arranged circumferentially within the first permanent magnet 111, dividing the first permanent magnet 111 into ten first permanent magnet sub-segments by the spacing slots. In an embodiment according to the present disclosure, the spacing slots 113 penetrate the first permanent magnet 111 in the longitudinal direction, that is, the axial direction of the first permanent magnet 111. The second permanent magnets 112 are respectively arranged in the ten spacing slots 113, and in particular, are inserted into the spacing slots 113. The rotor 110 has ten alternating magnetic poles, that is, alternating N poles and S poles, as shown in FIG1. ​​The spacing slots 113 are configured to accommodate a magnetic field applying device during the orientation process, so that the first permanent magnet 111 obtains a deeper orientation, and also to accommodate another magnetic field applying device during the magnetization process, so that the first permanent magnet 111 obtains a stronger permanent magnetism.

[0041] In an embodiment of the present disclosure, the first permanent magnet 111 of the rotor 110 can be made of a material with a low magnetic energy product, such as plastic ferrite. Plastic ferrite is a mixture of ferrite and nylon. During the injection molding process of the plastic ferrite into the first permanent magnet 111, a magnetic field application device, i.e., a strong magnetic orientation device, is placed in the spacing slots 113 of the first permanent magnet 111 to orient the first permanent magnet 111. After orientation, the small magnetic poles in the first permanent magnet 111 are aligned in the desired magnetic field direction. This results in a stronger magnetism for the magnetized first permanent magnet 111. During the magnetization process, a magnetic field application device, i.e., a strong magnetic magnetization device, is placed in the spacing slots 113 of the first permanent magnet 111 to magnetize the first permanent magnet 111, thereby imparting permanent magnetism to the first permanent magnet 111. The provision of the spacing slots 113 allows the first permanent magnet 111 to achieve a deep magnetization depth and magnetization depth. Furthermore, plastic ferrite has a lower density than silicon steel, which reduces the weight of rotors made from it, thereby improving the power and energy efficiency of motors. Furthermore, plastic ferrite has a higher resistivity than silicon steel, so rotors made from plastic ferrite can effectively reduce eddy current losses compared to rotors made from silicon steel.

[0042] The stator 120 is constructed as a hollow cylinder. This is particularly understood to mean that the outer contour of the stator 120 is a hollow cylinder. In the present disclosure, the stator 120 is constructed as a hollow cylinder, in particular, it is understood that the outer contour of the stator 120 is a hollow cylinder. The stator 120 is arranged with twelve slots 121 in the circumferential direction. The slots 121 respectively have radially inward slots 1211. The slots 121 are used to accommodate stator windings, and the stator windings are used to generate a rotating magnetic field. In an embodiment according to the present disclosure, a tooth portion 122 is formed between two adjacent slot portions 121, and a tooth shoe 1221 is formed at the end of the tooth portion 122. A slot 1211 is respectively formed between adjacent tooth shoes 1221. In an embodiment according to the present disclosure, the slot portion 121 can be designed as a pear-shaped slot or a flat-bottomed slot, for example.

[0043] In some cases, the traditional permanent magnet rotor in a permanent magnet synchronous motor is composed of a permanent magnet and a magnetizer, wherein the permanent magnet is made of rare earth material and the magnetizer is made of stacked silicon steel sheets. The permanent magnet can be attached to the surface of the magnetizer to form a surface-mounted rotor, or the permanent magnet can be inserted into the magnetizer to form an embedded rotor. The disadvantage of this rotor is that the magnetizer itself takes up space in the rotor but cannot provide magnetic flux. It only serves as a magnetic conductor, and the process of stamping silicon steel sheets is complicated and the cost of silicon steel sheets is high. Compared with the above situation, a first permanent magnet is used in the rotor of the motor according to the present disclosure to replace the magnetizer. The first permanent magnet itself can provide magnetic force, and its magnetic permeability is much higher than that of the silicon steel sheet magnetizer. Therefore, the rotor of the motor according to the present disclosure has a higher power density. In addition, the first permanent magnet according to the present disclosure can be injection molded from a plastic magnetic material, so it can be very conveniently prepared through an integrated molding process. The integrated molding process of the first permanent magnet is simple, efficient, precise and low-cost compared to the process of stamping and stacking silicon steel sheets.

[0044] In some cases, the permanent magnets in the rotor are made of rare earth materials with high magnetic energy product, such as neodymium iron boron. Rare earth materials, as national strategic resources, are very expensive, resulting in high costs for permanent magnets made from rare earth materials. In addition, when the size or volume of permanent magnets made from rare earth materials is large, the permanent magnet cannot be magnetized very deeply, resulting in its magnetism being concentrated on the surface of the permanent magnet. For these two reasons, traditional rotors are not designed to be too large. When permanent magnets are made from rare earth, an oversized rotor is not only expensive but also wastes expensive rare earth materials. The first permanent magnet in the rotor of the motor according to the present disclosure can provide a magnetic field and magnetic flux, so the second permanent magnet can be made using less rare earth material, or the second permanent magnet can also be made of sintered ferrite. According to some embodiments of the present disclosure, the second permanent magnet is made of one or more of ferrite, neodymium iron boron, samarium iron nitrogen, and samarium cobalt. In either case, the rotor of the motor according to the present disclosure has a lower cost.

[0045] In general, the rotor of the permanent magnet synchronous motor according to the present disclosure is mainly made of ferrite, without using silicon steel sheets, using only a small amount of rare earth materials or not using any rare earth materials at all. The rotor of the motor according to the present disclosure can also provide the same magnetic flux as a traditional permanent magnet rotor.

[0046] Plastic ferrite is a material with low magnetic energy product. While the rotor according to the present disclosure provides the same magnetic flux as a conventional permanent magnet rotor, the rotor of the motor according to the present disclosure has a larger diameter. In practical applications, permanent magnet synchronous motors typically have standard sizes to facilitate application in different devices and scenarios. This standard size is reflected in a specific radius size or a specific shaft center height of the permanent magnet synchronous motor as a whole. Therefore, when the radius of the motor as a whole is constant and the radius of the rotor is larger, the outer diameter of the stator remains unchanged and the inner diameter of the stator increases. In other words, the stator of the permanent magnet synchronous motor according to the present disclosure becomes thinner. Figure 3 shows a schematic cross-sectional view of the stator 120 of the permanent magnet synchronous motor 100 according to an embodiment of the present disclosure. Figure 3 specifically shows the outer diameter D of the stator 120 and the inner diameter d of the stator 120. In an embodiment according to the present disclosure, the ratio of the outer diameter to the inner diameter (D / d) of the stator 120 is in the range of 1.34 to 1.53. This ratio varies within the above range as the motor size, such as the stator diameter, changes. Compared to the stator of the synchronous motor according to the present disclosure, the stator of a conventional permanent magnet synchronous motor, i.e., a permanent magnet synchronous motor whose rotor uses rare earth materials for its permanent magnets, has a thicker stator, with an outer diameter to inner diameter ratio (D / d) ranging from 2.10 to 2.25. Due to the thinner stator design, the stator of the permanent magnet synchronous motor according to the present disclosure uses less silicon steel sheets and less stator coils, i.e., less copper. This further reduces the cost of manufacturing the permanent magnet synchronous motor according to the present disclosure.

[0047] In an embodiment of the present disclosure, the stator 120 can be divided into a plurality of stator sub-segments 310 along the centerline of each slot 121. Each stator sub-segment 310 has a tooth portion 122, and the cross-section of the stator sub-segment 310 is a curved "I" shape, as shown in FIG3 . In other words, the cross-section of the stator 120 is annular, and the stator 120 is divided into a plurality of sector ring segments along the centerline of each slot 121. In this embodiment, the stator 120 is divided into twelve sector ring segments, i.e., twelve stator sub-segments 310. Because each sector ring segment contains a tooth portion 122 and a tooth shoe 1221, the cross-section of the sector ring segment is a curved "I" shape. The ratio of the arc length of the outer diameter to the arc length of the inner diameter of the stator sub-segment 310 or sector ring segment is equal to the ratio of the outer diameter to the inner diameter of the stator 120. In an embodiment of the present disclosure, the ratio of the outer diameter arc length to the inner diameter arc length of the stator sub-section 310 is in the range of 1.34 to 1.53.

[0048] Slots 1211 are formed between adjacent tooth shoes 1221. In embodiments of the present disclosure, the width H of slots 1211 can be, for example, in the range of 0.6 to 2 mm. The width H of slots 1211 increases, for example, as the stator outer diameter increases. Compared to the slots of conventional permanent magnet synchronous motor stators, the slot width in embodiments of the present disclosure is significantly smaller, even smaller than the diameter or side length of the stator conductors arranged in the slots.

[0049] In an embodiment of the present disclosure, based on a very small slot width, the ratio of the outer diameter arc length L of the stator subsection 310 to the tooth shoe arc length k (L / k) can be, for example, in the range of 1.42 to 1.60. This ratio varies within the above range as the motor size, such as the stator diameter, changes. Compared to the stator of the synchronous motor according to the present disclosure, the stator of a conventional permanent magnet synchronous motor, i.e., a permanent magnet synchronous motor in which the permanent magnets in the rotor are made of rare earth materials, has a thicker stator and a larger slot width. Therefore, the ratio of the outer diameter arc length of the stator subsection to the tooth shoe arc length (L / k) thereof is in the range of 2.50 to 3.30.

[0050] This very small slot width reduces the gap between adjacent tooth shoes. This reduces stator magnetic flux leakage, thereby reducing motor losses and improving motor power and efficiency. This very small slot width also increases the overlap area between the arcuate surface of the stator tooth shoe and the circumferential surface of the rotor, thereby increasing the motor's power density and torque.

[0051] The large overlap area between the tooth shoe arc surface of the stator tooth portion and the rotor circumferential surface can be reflected, for example, by the ratio of the interpole arc length of adjacent poles of the rotor to the outer diameter arc length of the stator sub-portion, or by the ratio of the interpole arc length of adjacent poles of the rotor to the tooth shoe arc length. Figure 4 shows a cross-sectional schematic diagram of the rotor 110 of the permanent magnet synchronous motor 100 according to an embodiment of the present disclosure. The interpole arc length J of adjacent poles of the rotor 110 can be, for example, the arc length from the S pole to the adjacent N pole on the outer circumference of the rotor, or it can be the outer diameter arc length between the second permanent magnets 112, and the arc lengths of the two are equal.

[0052] In an embodiment according to the present disclosure, the ratio (J / L) of the interpole arc length J between adjacent poles of the rotor 110 to the outer diameter arc length L between adjacent slots 121 of the stator 120 (i.e., the outer diameter arc length L of the stator subsection 310) can be, for example, in the range of 0.77 to 0.90. This ratio varies within the aforementioned range as the motor size, such as the stator diameter, changes. Compared to the stator of the synchronous motor according to the present disclosure, the stator of a conventional permanent magnet synchronous motor, i.e., a permanent magnet synchronous motor in which the permanent magnets in the rotor are made of rare earth materials, has a thicker stator and a larger slot width. Therefore, the ratio (J / L) of the interpole arc length J between adjacent poles of the rotor to the outer diameter arc length L between adjacent slots 121 of the stator 120 is in the range of 0.52 to 0.55.

[0053] In an embodiment according to the present disclosure, the ratio (k / J) of the arc length k of the tooth shoe of the stator 120 to the arc length J between the poles of the adjacent poles of the rotor 110 can be, for example, in the range of 0.78 to 0.81. This ratio varies within the above range as the motor size, such as the stator diameter, changes. Compared with the stator of the synchronous motor according to the present disclosure, the stator of a conventional permanent magnet synchronous motor, i.e., a permanent magnet synchronous motor in which the permanent magnets in the rotor are made of rare earth materials, has a thicker size and a larger slot width. Therefore, the ratio (k / J) of the arc length k of the tooth shoe of the stator to the arc length J between the poles of the adjacent poles of the rotor is in the range of 0.56 to 0.73.

[0054] The permanent magnet synchronous motor according to the present disclosure has a larger rotor diameter than conventional permanent magnet synchronous motors. Given a given overall motor diameter, the permanent magnet synchronous motor according to the present disclosure has a thinner stator. Therefore, the size of the rotor and stator of the permanent magnet synchronous motor according to the present disclosure differs significantly from that of conventional permanent magnet synchronous motors. Because the rotor of the permanent magnet synchronous motor according to the present disclosure has a larger diameter, the overlap area between the rotor and stator is larger, which improves the motor's power density and torque. The thinner stator of the permanent magnet synchronous motor according to the present disclosure reduces the amount of silicon steel sheets used and the amount of wire, i.e., copper, used in the stator, further reducing the motor's manufacturing cost. The smaller difference between the stator's inner and outer diameters shortens the magnetic circuit in the stator and reduces magnetic losses, thereby improving the motor's power and efficiency. Furthermore, the stator of the permanent magnet synchronous motor according to the present disclosure has a narrower slot, which reduces the gap between the tooth shoes and increases the overlap area between the rotor and stator, thereby improving the motor's power density and torque.

[0055] In general, the permanent magnet synchronous motor disclosed herein reduces the use of rare earth elements, copper, and silicon steel sheets, while also offering lower manufacturing costs. However, due to its structure, the synchronous motor disclosed herein can achieve very high power and energy efficiency levels. Therefore, the synchronous motor disclosed herein can be more easily and cost-effectively applied in a variety of equipment and applications.

[0056] FIG5 shows a schematic diagram of the magnetic circuit of the rotor 110 of the permanent magnet synchronous motor 100 according to an embodiment of the present disclosure. The rotor 110 has alternating north and south poles, forming a rotor with five pole pairs (10 poles). Within the rotor 110, the first permanent magnet subsegments corresponding to the south poles have a magnetic field direction extending radially inward, while the first permanent magnet subsegments corresponding to the north poles have a magnetic field direction extending radially outward. Between adjacent south and north poles, the magnetic field originates from the south pole, transitions through the second permanent magnet along the shortest path, and reaches the north pole. The magnetic field in the second permanent magnet extends circumferentially. FIG5 shows second permanent magnets 511, 512, and 513. The magnetic field direction of the second permanent magnet 513 extends along the circumference of the rotor 110 and is opposite to the magnetic field direction of the adjacent second permanent magnet 512. Flanking the second permanent magnet 512 are the first permanent magnet subsegments 521 and 522, and flanking the second permanent magnet 513 are the first permanent magnet subsegments 522 and 523. As can be seen in FIG5 , the magnetic field originates from the south pole corresponding to the first permanent magnet subsection 522 and extends inward in the radial direction of the first permanent magnet 111 within the first permanent magnet subsection 522. The magnetic field then splits, with one portion bending through the second permanent magnet 512 and the other portion bending through the second permanent magnet 513. The magnetic field extends counterclockwise in the circumferential direction of the rotor 110 within the second permanent magnet 512. After passing through the second permanent magnet 512, the magnetic field bends and extends outward in the radial direction of the first permanent magnet 111 through the first permanent magnet subsection 521, reaching the north pole corresponding to the first permanent magnet subsection 521. The magnetic field extends clockwise in the circumferential direction of the rotor 110 within the second permanent magnet 513. After passing through the second permanent magnet 513, the magnetic field bends and extends outward in the radial direction of the first permanent magnet 111 through the first permanent magnet subsection 523, reaching the north pole corresponding to the first permanent magnet subsection 523. Based on the above description of the directions and orientations of the magnetic fields in the first permanent magnet sub-portions 521 , 522 and 523 and the second permanent magnets 512 and 513 , the directions and orientations of the magnetic fields in the other first permanent magnet sub-portions and second permanent magnets can be understood by comparison.

[0057] Figure 6 shows a partial schematic diagram of the magnetic circuit of a permanent magnet synchronous motor 100 according to an embodiment of the present disclosure. Figure 6 illustrates the closed magnetic circuit formed by the magnetic field within the rotor 110 and stator 120. For example, the magnetic field originates from the first permanent magnet subsection 521 of the rotor 110 and extends radially outward within the first permanent magnet subsection 521. This magnetic field passes through the air gap and slot gap between the rotor 110 and the stator 120 and reaches the tooth shoe of the stator 120. Specifically, the majority of the magnetic field passes through the air gap and reaches the tooth shoe 6121, while a smaller portion passes through the air gap and reaches the tooth shoe 6221, passing through the slot 6121 and also reaching the tooth shoe 6211. The magnetic field then extends radially outward within the corresponding tooth portion 621 and reaches the stator yoke 620. The stator yoke 620 is formed at the outermost periphery of the stator 120 and is a hollow cylinder. The stator yoke 620 is used to guide the magnetic field or magnetic flux through and form a closed magnetic circuit. After reaching the stator yoke 620, a portion of the magnetic field bends and extends clockwise to the teeth 622. This portion of the magnetic field extends radially inward within the teeth 622 to the tooth shoe 6221, passing through the air gap and the slot 6131 of the slot 613 to reach the first permanent magnet sub-segment 522 of the rotor 110. In other words, this portion of the magnetic field extends clockwise around the slot 612. Another portion of the magnetic field bends and extends counterclockwise to the teeth 623. This portion of the magnetic field extends radially inward within the teeth 623 to the tooth shoe 6231, passing through the air gap to reach the first permanent magnet sub-segment 524 of the rotor 110. In other words, this other portion of the magnetic field extends counterclockwise around the slot 611. The magnetic field direction and magnetic path extension of the stator 120 around the slots 612 and 611 described above can be used to understand the magnetic field direction and magnetic path extension of the stator 120 around other slots. The magnetic circuit of stator 120 forms a closed magnetic circuit together with the magnetic circuit of rotor 110. The rotating magnetic field of stator 120 interacts with the magnetic field of rotor 110 and generates torque on rotor 110, causing rotor 110 to rotate at a synchronous speed.

[0058] Compared to the slots in conventional permanent magnet synchronous motor stators, the slot width of the stator slots of the permanent magnet synchronous motor according to the present disclosure is significantly smaller, even smaller than the diameter or side length of the stator conductors arranged in the slots. To arrange the stator coils or stator conductors in the slots, a new method for manufacturing a motor stator is required. This method includes: arranging the stator subsections in a straight line; arranging the stator conductors between the stator subsections; and joining the stator subsections to form the stator. Figures 7, 8, and 9 collectively illustrate a method for manufacturing a motor stator.

[0059] Figure 7 shows a schematic diagram of stator subsections 710 arranged in a straight line according to an embodiment of the present disclosure. The stator subsections 710 arranged in a straight line comprise a straight stator 700. The twelve stator subsections 710 shown in Figure 7 can be wound into a circle and welded to form a hollow cylindrical stator with twelve slots. When the stator subsections 710 are arranged in a straight line, the width of the slots 721 is very large, making it very easy to arrange the stator conductors in the slots 720. Figure 8 shows a schematic diagram of the stator subsections 710 arranged in a straight line after stator conductors 730 are arranged in the slots 720 according to an embodiment of the present disclosure. As shown in Figure 8, the stator conductors 730 can be arranged in the slots 720 through the slots 721. After the stator conductors 730 are arranged in the slots 720, the individual stator subsections 710 are wound into a circle and joined, for example, by welding, to form a hollow cylindrical stator. Figure 9 shows a schematic diagram of a stator 900 formed by joining the stator subsections according to an embodiment of the present disclosure. As can be seen in Figure 9 , the resulting stator 900 has a very small slot width H. This slot width H is significantly smaller than the width or diameter of the stator conductor. This very small slot width reduces the gap between adjacent tooth shoes. This reduces stator magnetic flux leakage, thereby reducing losses and improving motor power and efficiency. This very small slot width also increases the overlap area between the arcuate surfaces of the stator tooth shoes and the circumferential surface of the rotor, thereby increasing the motor's power density and torque. In embodiments according to the present disclosure, the slot width H can be, for example, in the range of 0.6 to 2 mm, and increases with increasing stator outer diameter. For example, when the stator outer diameter is 78 mm, the slot width is, for example, 0.6 mm; when the stator outer diameter is 90 mm, the slot width is, for example, 1.2 mm; when the stator outer diameter is 110 mm, the slot width is, for example, 1.5 mm; and when the stator outer diameter is 175 mm, the slot width is, for example, 2 mm. Under these conditions, the motor stator can meet the mold strength when the stator is punched, and the motor with such a stator can achieve the best efficiency, the lowest noise and the largest torque.

[0060] According to an embodiment of the present disclosure, in the above-mentioned method for manufacturing a motor stator, during the process of arranging the stator conductor 730 on the straight stator 700, the stator manufacturing process can be improved by utilizing the terminal 8100 shown in Figures 10 and 11. Traditionally, in terms of stator manufacturing, the stator winding process itself can be completed on an automatic winding machine. However, after the winding is completed, it is necessary to manually straighten the lead wires and insert the terminals on the stator, and then fix the lead wires to the terminals to facilitate subsequent stator wiring.

[0061] As will be described in detail later, according to an embodiment of the present disclosure, terminals 8100 are provided on a plurality of stator subsections 710 configured as outlet wires of a straight stator 700. According to this embodiment, the terminals 8100 are configured such that, during the process of placing the wires of the stator conductors 730 in the slots 720, a section of the wire is guided through a wire passing space 8150 formed by the terminals 8100 at an appropriate time so that the section can subsequently be fixed to the terminals 8100.

[0062] The terminal 8100 shown in Figures 10 and 11 facilitates directing the stator conductor wires to the terminal during stator winding, making it suitable for automated winding and wire securing, significantly simplifying and accelerating the stator manufacturing process. For example, when using enameled wire as the stator conductor, the stator manufacturing process is further accelerated, and the stator conductor wire securing process is further improved.

[0063] Figure 10 is a perspective view of the terminal 8100. Figure 11 is a six-view view of the terminal 8100. As shown in Figures 10 and 11, the terminal 8100 includes a terminal body 8110 and a terminal head 8120 and a terminal tail 8130 connected to the terminal body 8110. The terminal 8100 is configured to be attached to the stator through the terminal tail 8130, as described in detail later. A first direction 8111 is defined from the terminal tail 8130 to the terminal head 8120, and a second direction 8112 opposite to the first direction 8111 is defined from the terminal head 8120 to the terminal tail 8130. The terminal body 8110, the terminal head 8120 and the terminal tail 8130 can be made of a single sheet and are located in the same plane. Figure 10 shows a third direction 8113 and a fourth direction 8114 located in the plane, which are orthogonal to the first direction 8111 and the second direction 8112.

[0064] As shown in FIG10 , the terminal head 8120 includes a through hole 8121 for improving the fixation between the terminal and a wire (not shown) connected externally to the stator. Furthermore, the distal end of the terminal head 8120 may also have a plurality of chamfered portions 8122 (see also FIG11 ) to facilitate handling when connecting and fixing the wires.

[0065] As shown in Figures 10 and 11, terminal 8100 further includes a wire channel 8140 connected to terminal body 8110. Wire channel 8140 includes a first pressing piece 8300 and a second pressing piece 8400. The first pressing piece 8300 and the second pressing piece 8400 are connected to each other at their respective sides 8320 and 8420 via a connecting portion 8155. In Figures 10 and 11, connecting portion 8155 is shown as a segment connecting the first pressing piece 8300 and the second pressing piece 8400 and having an arcuate cross-section. This reduces the risk of accidental damage to connecting portion 8155 and simplifies the manufacturing process of terminal 8100. However, in embodiments not shown, connecting portion 8155 may have other specific configurations. For example, the sides 8320 and 8420 of the first pressing piece 8300 and the second pressing piece 8400 may be substantially directly connected, thereby having a narrower cross-section.

[0066] As shown in Figures 10 and 11, the second pressing piece 8400 extends at an angle relative to the first pressing piece 8300, thereby forming a wire passing space 8150 open along the first direction 8111 between the first pressing piece 8300 and the second pressing piece 8400. As a result, the wire passing space 8150 can receive the enameled wire placed between the first pressing piece 8300 and the second pressing piece 8400 along the second direction 8112, and then, the first pressing piece 8300 and the second pressing piece 8400 can be pressed toward each other by an external force (for example, an external force in a direction perpendicular to the plane where the terminal body 8110 is located) to fix the enameled wire. To this end, for example, the first pressing piece 8300 and the second pressing piece 8400 can form an acute angle between them, and the angle can be, for example, between 10° and 80°, for example, between 30° and 60°, for example, between 40° and 50°. Thus, a wire-passing guiding direction 8151 (which is substantially parallel to the third direction 8113 and the fourth direction 8114 in FIG. 10 ) is defined between the first pressing piece 8300 and the second pressing piece 8400, wherein the enameled wire is configured in the wire-passing space 8150 to be guided by the first pressing piece 8300 and the second pressing piece 8400, thereby extending along the wire-passing guiding direction 8151. For example, in FIG. 10 and FIG. 11 , the wire-passing guiding direction 8151 may be specifically defined by the connecting portion 8155 between the first pressing piece 8300 and the second pressing piece 8400.

[0067] In Figures 10 and 11, the first pressing piece 8300 of the wire groove portion 8140 extends from the terminal body 8110, the connecting portion 8155 extends from the first pressing piece 8300, and the second pressing piece 8400 extends from the connecting portion 8155, so that the first pressing piece 8300 and the second pressing piece 8400 roughly form a V-shape. As a result, the entire terminal 8100 can be made of a single sheet, simplifying the manufacturing process. For example, the first pressing piece 8300 and the terminal body 8110 are in the same plane, so that the terminal 8100 can smoothly receive the enameled wire in the wire groove portion 8140, and has a further simplified manufacturing process. Of course, the present disclosure is not limited to the specific formation method of the first pressing piece 8300 and the second pressing piece 8400, and it is only necessary to form a wire space 8150 open along the first direction 8111 between them.

[0068] 10 and 11 , the first pressing piece 8300 may have a first side 8310 away from the connecting portion 8155, and the second pressing piece 8400 may have a second side 8410 away from the connecting portion 8155. An anti-slip beam 8361 extending along the first side 8310 and protruding from the first pressing piece 8300 is provided at an end of the first side 8310, and an anti-slip beam 8461, 8462 extending along the second side 8410 and protruding from the second pressing piece 8400 is provided at an end of the second side 8410. These anti-slip beams 8361, 8461, 8462 are configured to prevent the enameled wire 8251 (see also FIG. 14 and FIG. 15A ) located in the wire passing space 8150 from escaping from the wire passing space 8150, for example, during an automatic winding process.

[0069] In addition, as shown in Figures 10 and 11, the surface of the first pressing piece 8300 facing the second pressing piece 8400 is provided with a fixing rib 8350, and the surface of the second pressing piece 8400 facing the first pressing piece 8300 is provided with a fixing rib 8450. These fixing ribs 8350 and 8450 are used to further secure the enameled wire between the first pressing piece 8300 and the second pressing piece 8400. According to Figures 10 and 11, the first pressing piece 8300 is provided with multiple fixing ribs 8350 (for example, four fixing ribs 8350), and the fixing ribs 8350 extend from the connecting portion 8155 toward the free end of the first pressing piece 8300 that is not connected to the connecting portion 8155 or the terminal body 8110, for example, toward the first side 8310. For example, the multiple fixing ribs 8350 are arranged parallel to each other and extend from the connecting portion 8155 to the first side 8310. The second pressing piece 8400 is provided with a plurality of fixing ribs 8450 (e.g., three fixing ribs 8450), and the fixing ribs 8450 extend from the connecting portion 8155 toward a free end of the second pressing piece 8400 that is not connected to the connecting portion 8155, for example, toward the second side 8410. For example, the plurality of fixing ribs 8450 are arranged parallel to each other and extend from the connecting portion 8155 to the second side 8410.

[0070] 12 , the plurality of fixing ribs 8350 of the first pressing plate 8300 and the plurality of fixing ribs 8450 of the second pressing plate 8400 are alternately arranged along the wire-passing guide direction 8151. This allows the enameled wire to be more securely secured between the first pressing plate 8300 and the second pressing plate 8400, and reduces the likelihood of the enameled wire being pinched off between the first pressing plate 8300 and the second pressing plate 8400. For example, in FIG12 , the fixing ribs 8350 and 8450 are arranged parallel to each other, thereby forming a staggered arrangement. This allows the enameled wire to be particularly securely secured between the first pressing plate 8300 and the second pressing plate 8400.

[0071] Continuing with reference to FIG12 , each fixing rib 8350 has a cross-section with respect to the surface of the first pressing plate 8300 having a raised portion 8351 and a recessed portion 8352 (for clarity of the drawing, only a portion of the raised portions 8351 and recessed portions 8352 are shown). For example, in FIG12 , the cross-section of each fixing rib 8350 has two raised portions 8351 and a recessed portion 8352 located between the two raised portions 8351. Each fixing rib 8450 has a cross-section with respect to the surface of the second pressing plate 8400 having a raised portion 8451 and a recessed portion 8452 (for clarity of the drawing, only a portion of the raised portions 8451 and recessed portions 8452 are shown). For example, in FIG12 , the cross-section of each fixing rib 8450 has two raised portions 8451 and a recessed portion 8452 located between the two raised portions 8451.

[0072] As shown in Figure 12, when the enameled wire is clamped between the first pressing plate 8300 and the second pressing plate 8400, at least the tip portion of the fixing ribs 8350 and 8450 (the tip portion corresponds to the tip portion of the raised portion 8351 and 8451 in the cross section of the fixing ribs 8350 and 8450) can contact the conductive inner core of the enameled wire in the section 8251 located in the wire passing space 8150, and can ensure close contact and prevent loosening. In addition, by providing the recessed portion 8452, the contact area between the terminal 8100 and the conductive inner core of the enameled wire can be further increased, depending on the materials of the terminal 8100 and the conductive inner core of the enameled wire. For example, the contact area may include the tip portion of the fixing ribs 8350 and 8450, the portion near the tip portion closer to the pressing plate surface, and even a portion of the surface of the recessed portion 8452. Furthermore, by providing the cross-sectional shape of the fixing ribs 8350 and 8450 with alternating raised and recessed portions (e.g., forming the M-shaped cross-sectional profile shown in FIG. 12 ), the fixing ribs 8350 and 8450 can be formed using a convenient manufacturing process (e.g., stamping), while significantly improving the contact quality between the fixing ribs 8350 and 8450 and the conductive inner core of the enameled wire. This reduces vibration of the enameled wire during motor operation, thereby reducing high-frequency harmonics and lowering losses.

[0073] FIG13A and FIG13B illustrate the structure of a wound straight stator 8020 according to the present disclosure. Referring to FIG8 , in a wound straight stator, a stator conductor is wound around a stator subsection. For example, FIG13B schematically illustrates, in a top view, an enameled wire segment 8252 on straight stator 8020, which is a portion of the stator conductor.

[0074] Figures 13A and 13B are rear and top views, respectively, of a straight stator 8020 in an inline configuration. Straight stator 8020 includes a plurality of stator units 8200, which are sequentially connected to form the straight stator shown in Figures 13A and 13B. The straight stator 8020 shown in Figures 13A and 13B includes 12 sequentially connected stator units 8200. Therefore, according to an embodiment of the present disclosure, the stator units 8200 of Figures 13A and 13B may correspond to the stator subsection 710 shown in Figure 8.

[0075] As shown in Figures 13A and 13B, for example, the straight stator 8020 may include a straight stator core (e.g., a straight stator core, or a plurality of silicon steel sheet laminates arranged in a straight line) formed by sequentially connecting a plurality of stator core monomers (e.g., a plurality of stator iron core monomers, or a plurality of silicon steel sheet laminates). For example, each stator core monomer may also be coated with a stator skeleton 8212, such as a stator skeleton 8212 made of a polymer. In addition, the enameled wire is configured to be wound around the outer periphery of each stator monomer 8200. In the perspective shown in Figure 13A, the plane formed by the winding of the enameled wire can be roughly parallel to the paper surface, that is, when the enameled wire is wound, the extension direction of the enameled wire is always roughly parallel to the paper surface. As described above, generally, after winding, the straight stators in the straight state are connected end to end to form a circular stator, that is, the state of being installed in the housing is roughly formed by winding (hereinafter referred to as the "rolled state").

[0076] Figure 13A is a rear view of the straight stator 8020 in an inline state. For ease of explanation, the opposite axial end faces of the straight stator 8020 in the rolled state are referred to as the first axial end face and the second axial end face. Thus, each stator cell has a stator cell first side face 8221 (also referred to as the stator sub-section first side face) corresponding to the first axial end face and a stator cell second side face 8222 (also referred to as the stator sub-section second side face) corresponding to the second axial end face (indicated by arrows in Figure 13A , respectively). Figure 13B is a top view of the straight stator 8020 in an inline state. The straight stator 8020 in the rolled state has a radially outer side face and a radially inner side face. Thus, each stator cell has a stator cell outer side face 8223 (also referred to as the stator sub-section outer side face) corresponding to the radially outer side face and a stator cell inner side face 8224 (also referred to as the stator sub-section inner side face) corresponding to the radially inner side face (indicated by arrows in Figure 13B , respectively).

[0077] Figures 13A and 13B also show four terminal stator monomers 8201, 8202, 8203, and 8204. These four terminal stator monomers 8201, 8202, 8203, and 8204 are provided with terminals 8100 of the aforementioned structure. The straight stator 8020 is connected to a wire (not shown) via the terminals 8100 provided on these four terminal stator monomers, and is then connected to, for example, an external power supply or other connections via each wire. It should be noted that the selection of terminal stator monomers in Figures 13A and 13B is merely an example, and the present disclosure is not intended to limit the specific selection of terminal stator monomers, but rather can be adjusted according to the predetermined wiring conditions of the stator. For example, other stator monomers 8200 among the 12 stator monomers 8200 can be selected as terminal stator monomers according to specific circumstances such as the application. As mentioned above, the terminal stator monomers can also be referred to as terminal stator sub-parts 8201, 8202, 8203, and 8204.

[0078] As shown in Figures 13A and 13B, and also referring to Figures 14 and 15A, each terminal 8100 is configured to be inserted into the stator frame 8212 of the corresponding terminating stator cell 8201, 8202, 8203, and 8204, and to be mounted on the stator cell first side 8221 of the corresponding terminating stator cell. For example, the terminal 8100 can be inserted into the terminal notch 8213 on the corresponding stator frame 8212. According to an embodiment of the present disclosure, for example, the terminal tail 8130 of the terminal 8100 can be inserted into the terminal notch 8213. The terminal notch 8213 is open in a direction from the stator cell second side 8222 to the stator cell first side 8221. In addition, the terminal 8100 and the stator frame 8212 can be configured so that the terminal slot 8213 is open along the first direction 8111 of the terminal 8100, thereby facilitating the insertion of the terminal 8100 into the terminal slot 8213 and facilitating the automation of the terminal insertion process.

[0079] Furthermore, the configuration of the terminal 8100 and the stator frame 8212 is such that the wire passage space 8150 of the terminal 8100 is open in a direction pointing from the second side surface 8222 of the stator unit to the first side surface 8221 of the stator unit. This orientation and positional arrangement of the terminal 8100 and the corresponding terminating stator unit is particularly suitable for the automated manufacturing of the entire straight stator 8020, because an automatic winding machine can guide the enameled wire through the wire passage space 8150 of the terminal 8100 (see FIG. 15A ) along a motion path similar to the motion path used when winding the wire on the first side surface 8221 of the stator unit, and in a motion direction similar to or identical to the winding direction 8255 (i.e., the wire passage guiding direction 8151). This arrangement significantly improves the degree of automation of the manufacturing process, as described in detail below.

[0080] In addition, according to an unillustrated embodiment of the present disclosure, the stator frame 8212 may not be provided on the stator unit 8200 (i.e., the stator sub-section), and the terminal 8100 may be fixed to the stator unit 8200 in another manner. For example, the terminal 8100 may be directly inserted into and fixed to the slot of the stator unit core of the stator unit 8200. On the other hand, the structure of the terminal 8100 itself and its position and orientation relative to the stator unit 8200 are the same as those in the aforementioned embodiment. Alternatively, in the absence of the stator frame 8212, the terminal 8100 may be fixed to the stator unit 8200 in another manner. In other words, a stator sub-section may be formed in which only the terminal 8100 is provided.

[0081] In addition, referring to Figures 13A to 15B , each terminal 8100 can be positioned on the first side surface 8221 of the stator unit such that its second pressing piece 8400 extends toward the outer side surface 8223 of the stator unit and extends across the outer side surface 8223 of the stator unit when the second pressing piece 8400 is not pressed against the first pressing piece 8300. For example, each terminal 8100 can be positioned such that its wire guide direction 8151 is parallel to the extension direction 8255 of the enameled wire on the first side surface 8221 of the stator unit. In other words, the wire guide direction 8151 can be parallel to the in-line direction of the straight stator 8020, that is, the tangential direction of the straight stator 8020 in the rolled state. The above-mentioned various orientations and positional arrangements of the terminal 8100 and the corresponding terminating stator unit are further suitable for automated manufacturing of the entire straight stator 8020, as described in detail below.

[0082] In the traditional manufacturing process for straight stators 8020, wire winding is first performed on each stator. The subsequent steps of straightening the outgoing wires, inserting the terminals, and securing the enameled wire to the terminals all require manual operation. However, the solution disclosed herein can significantly improve the level of automation. For example, an automatic terminal insertion machine can first insert each terminal 8100 into the corresponding terminal stator unit 8201, 8202, 8203, and 8204. Then, an automatic winding machine can perform the winding. Unlike traditional manufacturing processes, according to the present disclosure, the automatic winding machine can guide the enameled wire through each terminal 8100 at the appropriate time during the winding process, thereby placing the enameled wire segment 8251 configured as the outgoing wire into the wire passage space 8150 of the terminal 8100. After the winding is completed, an automatic welding machine can press the first pressing plate 8300 and the second pressing plate 8400 against each other and apply heat, causing the lacquer on the enameled wire segment 8251 located in the wire passage space 8150 to melt. Afterwards, the automatic welding machine further presses the first pressing sheet 8300 and the second pressing sheet 8400 against each other, thereby pressing and fixing the enameled wire segment 8251 between the first pressing sheet 8300 and the second pressing sheet 8400, and forming a strong conductive connection with the first pressing sheet 8300 and the second pressing sheet 8400. Finally, the enameled wire 8250 can be appropriately sheared by an automatic wire cutting machine (for example, when the entire straight stator 8020 is wound with continuous enameled wire) to complete the winding and enameled wire outlet fixing process. Among them, the automatic winding machine used for the above-mentioned fully automated process does not require at least hardware modifications to existing machines, thereby significantly reducing application costs. In particular, the above process forms a complete automation of the terminal plug-in process, simplifies the process, and is therefore suitable for large-scale industrial manufacturing.

[0083] 13A to 15B , the terminal 8100 can be configured such that, when the first pressing piece 8300 and the second pressing piece 8400 of the terminal 8100 are pressed against each other (e.g., the second pressing piece 8400 moves closer to the first pressing piece 8300 due to plastic deformation of the connection portion 8155), the first pressing piece 8300 and the second pressing piece 8400, which are close to each other, are positioned between the stator unit outer side surface 8223 and the enameled wire segment 8252 located on the stator unit first side surface 8221 in a direction perpendicular to the stator unit outer side surface 8223. Thus, after the straight stator 8020 is wound, terminated, and rolled, it can be placed in the stator housing without any other shape modifications, thereby saving manufacturing steps.

[0084] Next, referring to Figure 16 , a device for securing the ends of the enameled wires used in the aforementioned terminals 8100 and the straight stator 8020 will be described. As previously described, after winding, the enameled wire segments 8251 in the wire passage spaces 8150 can be secured between the first pressing plate 8300 and the second pressing plate 8400 using an automatic welding machine. The welding machine can include a first electrode rod 8801 and a second electrode rod 8802 arranged horizontally in Figure 16 . The first electrode rod 8801 and the second electrode rod 8802 can also be positioned horizontally relative to each other. Therefore, when the first electrode rod 8801 and the second electrode rod 8802 are arranged on either side of the wire slot 8140 of the terminal 8100 (i.e., the two electrode rods are respectively close to the first pressing plate 8300 and the second pressing plate 8400), the first electrode rod 8801 and the second electrode rod 8802 move toward each other to contact the first pressing plate 8300 and the second pressing plate 8400, respectively. Then, an electric current is applied to heat the first pressing plate 8300 and the second pressing plate 8400, thereby melting the varnish on the surface of the enameled wire segment 8251. Thereafter, the first electrode rod 8801 and the second electrode rod 8802 further move toward each other to compress the first pressing plate 8300 and the second pressing plate 8400. Thus, according to the present disclosure, at least the tip portion of the raised portions 8351 and 8451 in the cross-section of the fixing ribs 8350 and 8450 of the terminal 8100 can directly contact the conductive inner core of the enameled wire segment 8251. And due to the structure of terminal 8100, the contact has an increased contact area and the contact is firm.

[0085] Furthermore, for example, by controlling the current to control the heating temperature of the enameled wire segment 8251, the varnish on the surface of the enameled wire segment 8251 can be melted. After the first pressing piece 8300 and the second pressing piece 8400 are pressed against each other, and the fixing ribs 8350 and 8450 contact and compress the conductive inner core of the enameled wire 8251, the varnish covers the fixing ribs 8350 and 8450 and the conductive inner core of the enameled wire segment 8251. This effectively isolates the conductive inner core of the enameled wire from the air, preventing oxidation of the conductive inner core.

[0086] In this document, unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by persons of ordinary skill in the field to which the present disclosure belongs. The words "first", "second" and similar terms used in the patent application specification and claims of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "a" do not necessarily indicate a quantity limitation. Words such as "include" or "comprising" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0087] The exemplary implementation schemes proposed in the present disclosure are described in detail above with reference to preferred embodiments. However, it will be understood by those skilled in the art that, without departing from the concept of the present disclosure, various modifications and variations can be made to the above-mentioned specific embodiments, and various technical features and structures proposed in the present disclosure can be combined in various ways without exceeding the scope of protection of the present disclosure, which is determined by the appended claims.

Claims

1. A permanent magnet synchronous motor comprising a rotor and a stator, in, The rotor includes a first permanent magnet and a second permanent magnet. The first permanent magnet is configured as a cylinder and is integrally formed. Ten spacing slots are arranged in the circumferential direction inside the first permanent magnet. The second permanent magnet is arranged in the spacing slots. The rotor has ten alternating magnetic poles. The spacing groove is used to accommodate a magnetic field applying device during the orientation and magnetization process, so that the first permanent magnet obtains permanent magnetism. The stator is constructed as a hollow cylinder, and twelve slots are arranged in the circumferential direction. The slots are used to accommodate stator windings, a tooth portion is formed between two adjacent slots, a tooth shoe is formed at the end of the tooth portion, and a slot is formed between adjacent tooth shoes.

2. The motor according to claim 1, wherein The first permanent magnet is made of plastic ferrite.

3. The motor according to claim 1, wherein The second permanent magnet is made of one or more of ferrite, neodymium iron boron, samarium iron nitrogen and samarium cobalt.

4. The motor according to claim 1, wherein A ratio of an outer diameter to an inner diameter of the stator is in a range of 1.34 to 1.

53.

5. The motor according to claim 1, wherein The stator is divided into a plurality of stator sub-sections along the center lines of the slots. Each stator sub-section has one tooth portion. The cross section of the stator sub-section is an I-shape with a curvature.

6. The motor according to claim 1, wherein The width of the notch is in the range of 0.6 to 2 mm.

7. The motor according to claim 5, wherein A ratio of an outer diameter arc length of the stator subsection to an arc length of the tooth shoe is in a range of 1.42 to 1.

60.

8. The motor according to claim 1, wherein A ratio of an inter-pole arc length between adjacent poles of the rotor to an outer diameter arc length between adjacent slot portions of the stator is in a range of 0.77 to 0.

90.

9. The motor according to claim 1, wherein A ratio of an arc length of a tooth shoe of the stator to an arc length between adjacent poles of the rotor is in a range of 0.78 to 0.

81.

10. The motor according to claim 1, wherein The groove portion is designed as a pear-shaped groove or a flat-bottomed groove.

11. The motor according to claim 1, wherein The stator is divided into a plurality of stator sub-sections along the center lines of the slots, and the stator is formed by rolling a straight stator bar. A portion of the plurality of stator sub-sections is provided with terminals to form terminal stator sub-sections. Wherein, the terminal includes: Terminal body; a terminal head and a terminal tail, the terminal head and the terminal tail being connected to the terminal body, the terminal being configured to be attached to the stator via the terminal tail, a first direction being defined from the terminal tail to the terminal head; A wire-passing groove portion is connected to the terminal body and includes a first pressing piece and a second pressing piece extending at an angle relative to the first pressing piece, wherein a wire-passing space open along the first direction is formed between the first pressing piece and the second pressing piece. Wherein, a surface of the first pressing sheet facing the second pressing sheet and a surface of the second pressing sheet facing the first pressing sheet are both provided with fixing ribs.

12. The electric machine according to claim 11, wherein The first pressing plate is provided with a plurality of fixing ribs, and the plurality of fixing ribs of the first pressing plate extend from the connecting portion between the first pressing plate and the second pressing plate toward the free end of the first pressing plate. The second pressing plate is provided with a plurality of fixing ribs, and the plurality of fixing ribs of the second pressing plate extend from the connecting portion between the first pressing plate and the second pressing plate toward the free end of the second pressing plate. A wire-passing guiding direction is defined between the first pressing plate and the second pressing plate, and the plurality of fixing ribs of the first pressing plate and the plurality of fixing ribs of the second pressing plate are alternately arranged along the wire-passing guiding direction.

13. The motor according to claim 11, wherein The cross section of the fixing rib of the first pressing sheet has a convex portion and a concave portion relative to the surface of the first pressing sheet, and the cross section of the fixing rib of the second pressing sheet has a convex portion and a concave portion relative to the surface of the second pressing sheet.

14. The motor according to claim 11, wherein The first pressing sheet has a first side away from the connection portion between the first pressing sheet and the second pressing sheet, the second pressing sheet has a second side away from the connection portion, the end of the first side is provided with an anti-slip beam portion extending along the first side and protruding from the first pressing sheet, the end of the second side is provided with an anti-slip beam portion extending along the second side and protruding from the second pressing sheet, wherein the anti-slip beam portion is configured to prevent the enameled wire located in the wire passing space from escaping from the wire passing space.

15. The motor according to claim 11, wherein The stator frame terminating each of the stator sub-sections includes a terminal notch opened in the first direction, and the terminal tail portion of the terminal is inserted into the terminal notch.

16. The electric machine according to claim 11, wherein Each of the terminal stator subsections has a stator subsection first side surface and a stator subsection second side surface, the stator subsection first side surface and the stator subsection second side surface corresponding to a first axial end surface and a second axial end surface of the stator facing oppositely to each other, respectively. The terminal terminating each stator sub-section is mounted on the first side surface of the stator sub-section, and the wire guiding direction of the terminal is parallel to the extension direction of the enameled wire on the first side surface of the stator sub-section.

17. The electric machine according to claim 16, wherein Each of the terminating stator subsections has a stator subsection outer side surface corresponding to a radially outer side surface of the stator, Wherein, for each of the terminated stator sub-sections, when the first pressing piece and the second pressing piece of the terminal are pressed against each other, the first pressing piece and the second pressing piece are positioned between the outer side surface of the stator sub-section and the enameled wire segment located on the first side surface of the stator sub-section in a direction orthogonal to the outer side surface of the stator sub-section.

18. The electric machine according to claim 11, wherein The protruding portion in the cross section of the fixing rib of the terminal defines a tip portion of the fixing rib, and the fixing rib contacts the conductive inner core of the enameled wire section located in the wire passing space at least with the tip portion.

19. The electric machine according to claim 18, wherein The varnish on the surface of the enameled wire section located in the wire passing space of the terminal is melted due to heating to cover the fixing rib and the conductive inner core of the enameled wire section.

20. A method for producing a stator for an electric machine according to any one of the preceding claims, wherein: The stator is divided into a plurality of stator sub-sections along the center lines of the slots, each stator sub-section has one tooth portion, and the cross section of the stator sub-section is an I-shape with a curvature; The method comprises: arranging the stator subsections in a straight line; arranging stator conductors between the stator subsections; and The stator subsections are joined to form the stator.

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