Rotor and permanent magnet synchronous motor

Abstract

This utility model discloses a rotor and a permanent magnet synchronous motor. The rotor, which is coupled to a stator, includes a rotor core and multiple magnetic poles. The rotor core has a circumferential mating surface opposite to the stator. Multiple attachment regions are formed on the circumferential mating surface, arranged in an array around the central axis of the rotor core. The multiple magnetic poles are correspondingly placed on the multiple attachment regions. Each magnetic pole includes two or more permanent magnets arranged circumferentially along the rotor core. The permanent magnets have rectangular cross-sections and include a first end face and a second end face opposite to the first end face. The first end face faces and connects to the attachment regions. The permanent magnets on the rotor have rectangular cross-sections that are easy to process and have low processing costs, reducing the difficulty and cost of processing the permanent magnets and improving material utilization. The second end face of each permanent magnet has a small surface area, resulting in smaller induced eddy currents in the rotating magnetic field, thus making the permanent magnet synchronous motor more efficient.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, specifically to a rotor and permanent magnet synchronous motor. Background Technology

[0002] With the continuous development of electric drive technology, permanent magnet synchronous motors (PMSMs) are widely used in the joint drive components of humanoid robots. Currently, most PMSMs used in humanoid robots employ surface-mounted rotors, where permanent magnets are glued to the surface of the rotor core to form the rotor. The permanent magnets provide the magnetic field for the rotor, and the interaction between the stator and rotor magnetic fields generates torque, driving the rotor to rotate. Typically, both the stator and rotor are cylindrical with circular cross-sections. To fit the circular surface of the rotor, the permanent magnets need to be machined into matching arc shapes, increasing the difficulty and cost of manufacturing them. Furthermore, because each pole has only one permanent magnet, the air gap in the PMSM is uneven, resulting in severe distortion of the air gap magnetic flux density waveform and increased torque fluctuations. Additionally, the large surface area of ​​each permanent magnet leads to significant eddy currents on the magnet surface, increasing motor losses. Utility Model Content

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the purpose of the present invention is to provide a rotor and a permanent magnet synchronous motor to solve the problems of high processing difficulty and cost of permanent magnets, large torque fluctuation of motors, and large motor losses in the prior art.

[0004] The objective of this utility model is achieved through the following technical solution:

[0005] The rotor, which cooperates with the stator, includes a rotor core and multiple magnetic poles. The rotor core has a circumferential mating surface opposite to the stator. Multiple attachment regions are formed on the circumferential mating surface, arranged in an array around the central axis of the rotor core. The multiple magnetic poles are placed on the multiple attachment regions one by one. The magnetic poles include two or more permanent magnets arranged circumferentially along the rotor core. The cross-section of the permanent magnet is rectangular. The permanent magnet includes a first end face and a second end face opposite to the first end face. The first end face faces the attachment region and is connected to the attachment region. According to the rotor of this utility model embodiment, each permanent magnet on the rotor can be a rectangular cross-section that is easy to process and has low processing cost. It is not necessary to process the permanent magnet into difficult-to-process shapes such as arc, bow, or bread shape, thereby reducing the difficulty and cost of permanent magnet processing, improving material utilization, and the regular shape of the permanent magnet can be easily mass-produced in the industrial sector. In addition, the second end face of each permanent magnet has a small surface area, resulting in smaller induced eddy currents in the rotating magnetic field, less heat generation of the permanent magnet, and less loss of the permanent magnet synchronous motor, making the permanent magnet synchronous motor more efficient.

[0006] In a preferred embodiment, an adhesive layer is filled between the first end face of the permanent magnet and the attachment area. The adhesive layer is used to fix the first end face of the permanent magnet to the attachment area. Using adhesive bonding facilitates the assembly of the permanent magnet and the rotor core, and allows for the bonding of a corresponding number of permanent magnets of appropriate sizes and specifications on the attachment area as needed.

[0007] In a preferred embodiment, a gap is formed between two adjacent permanent magnets in the magnetic pole to insulate and isolate them. During assembly, two or more permanent magnets on the magnetic pole are sequentially bonded to the attachment area. It is only necessary to control the spacing between two adjacent permanent magnets to form the aforementioned gap. In this way, the magnetic poles can be adapted according to actual needs.

[0008] In a preferred embodiment, the gap is filled with an insulating layer, or an insulating wrapping layer filled with the gap is covered on the outer surface of the permanent magnet. This ensures better insulation and isolation between adjacent permanent magnets while preventing magnetic field interference, thus improving the stability of the permanent magnet synchronous motor.

[0009] In a preferred embodiment, among two adjacent permanent magnets on the same magnetic pole, the second end face of one permanent magnet is offset by a distance Δd from the second end face of the other permanent magnet in the direction away from the central axis of the rotor core, where Δd > 0. The second end faces of the two adjacent permanent magnets have a certain height difference, which is equivalent to forming a step structure on the magnetic pole. During rotor rotation, this step structure of the magnetic pole acts as a pump, driving airflow between the rotor and stator. This allows the flowing air to carry away heat from the magnetic pole surface, enhancing the natural cooling effect of the permanent magnet synchronous motor.

[0010] In a preferred embodiment, the permanent magnet includes two sides, which are respectively connected between the two sides of the first end face and the second end face. In two adjacent permanent magnets of the same magnetic pole, the distance between the two sides of one permanent magnet is W1, and the distance between the two sides of the other permanent magnet is W2, where W1 > W2. Adjacent permanent magnets use different widths, and permanent magnets with different heights and widths are used at different pole arc positions to reduce the air gap magnetic flux density distortion and reduce the excitation of torque fluctuations.

[0011] In a preferred embodiment, the magnetic pole comprises three or more permanent magnets, with the height of the middle permanent magnet being greater than that of the two outer permanent magnets. This creates a surface on the magnetic pole that is concave in the center towards the central axis of the rotor core. By setting the surface of the magnetic pole to a concave shape, as the magnetic pole rotates with the rotor core, the airflow between the rotor and stator can form vortices at the concave position of the magnetic pole, allowing for more thorough heat exchange between the air and the magnetic pole surface, thus improving the natural cooling effect. Alternatively, the magnetic pole comprises three or more permanent magnets, with the height of the middle permanent magnet being less than that of the two outer permanent magnets. This creates a surface on the magnetic pole that is convex in the center away from the central axis of the rotor core. Setting the surface of the magnetic pole to a convex shape allows for smooth agitation of the airflow between the rotor and stator as the magnetic pole rotates with the rotor core, making the pumping effect of the magnetic pole more pronounced.

[0012] In a preferred embodiment, the magnetic pole comprises three or more permanent magnets, the height of which increases sequentially along the circumference of the rotor core, so that the surface of the magnetic pole forms at least two stepped structures. The use of multiple sizes and specifications of permanent magnets in the magnetic pole creates a stepped surface structure, further enhancing the pumping effect and natural cooling effect of the magnetic pole.

[0013] The permanent magnet synchronous motor includes a stator and the aforementioned rotor. The rotor core is cylindrical, and the circumferential mating surface is the outer edge surface of the rotor core. The stator is arranged around the outer periphery of the rotor core.

[0014] The permanent magnet synchronous motor includes a stator and the aforementioned rotor. The rotor core is cylindrical, with the circumferential mating surface being the inner edge surface of the rotor core. The stator is placed inside the rotor core.

[0015] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present utility model;

[0017] Figure 2 for Figure 1 View from direction A;

[0018] Figure 3 for Figure 2 Enlarged view at point B;

[0019] Figure 4 This is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0020] Figure 5This is a structural schematic diagram of Embodiment 3 of the present invention;

[0021] Figure 6 This is a structural schematic diagram of Embodiment 4 of the present invention;

[0022] Figure 7 This is a structural schematic diagram of Embodiment 5 of the present utility model;

[0023] Figure 8 for Figure 7 A magnified view of point C in the middle.

[0024] In the diagram: 100, stator; 200, rotor; 20, rotor core; 201, circumferential mating surface; 202, attachment area; 30, magnetic pole; 31, permanent magnet; 311, first end face; 312, second end face; 313, side face; 32, permanent magnet; 321, first end face; 322, second end face; 323, side face; 33, permanent magnet; 34, permanent magnet; 400, stator; 500, rotor; 50, rotor core; 60, magnetic pole. Detailed Implementation

[0025] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments. Unless otherwise specified, the materials and equipment used in this embodiment are all commercially available. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0026] In the description of this application, it should be understood that the terms "upper," "lower," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In the description of this application, "a plurality of" means two or more, unless otherwise precisely specified.

[0027] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected," "linked," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a connection through an intermediary, or a connection within two elements or an interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0028] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such process, method, product, or apparatus.

[0029] Figure 1 , 2Figure 3 illustrates the rotor of Embodiment 1 of this utility model and a permanent magnet synchronous motor having the rotor, which includes a rotor 200 and a stator 100. The rotor 200 and the stator 100 are coupled. Specifically, both the rotor 200 and the stator 100 are cylindrical, and the rotor 200 is located inside the hollow cavity of the stator 100. The rotor 200 includes a rotor core 20 and multiple magnetic poles 30. The rotor core 20 is cylindrical, and its outer periphery forms a circumferential mating surface 201 opposite to the stator 100. Multiple magnetic poles are formed around the rotor core 201 on the circumferential mating surface. The core 20 has attachment regions 202 arranged in an array along its central axis, with multiple magnetic poles 30 correspondingly placed on each attachment region 202. Each magnetic pole 30 includes two or more permanent magnets, which are arranged circumferentially along the attachment region 202. All permanent magnets have rectangular cross-sections. Each permanent magnet includes a first end face and a second end face opposite to the first end face. The first end face faces the attachment region 202 and is connected to it, while the second end face faces the stator 10. The inner edge of the rotor core 20; the attachment region 202 is part of the circumferential mating surface 201. Since it extends a certain dimension in the circumferential direction of the rotor core 20, the attachment region 202 has an arc-shaped structure. The magnetic pole 30 connected to the attachment region 202 is composed of two or more permanent magnets. Each permanent magnet has a relatively small width dimension. Therefore, when multiple permanent magnets on the magnetic pole 30 are individually connected to the attachment region 202, they can adapt to the arc-shaped structure of the attachment region 202. Thus, each permanent magnet can be a rectangular cross-section that is easy to process and has a low processing cost. There is no need to process the permanent magnet into difficult-to-process shapes such as arc, bow, or bread shapes, thereby reducing the difficulty and cost of permanent magnet processing, improving material utilization, and the regular shape of the permanent magnet can be easily mass-produced in the industrial industry. In addition, the second end face of each permanent magnet has a small surface area, resulting in a smaller induced eddy current in the rotating magnetic field, less heat generation of the permanent magnet, and less loss of the permanent magnet synchronous motor, making the permanent magnet synchronous motor more efficient.

[0030] In this invention, the magnetic pole 30 can be composed of two or more permanent magnets of the same size and specifications, or it can be composed of two or more permanent magnets of different sizes and specifications. In short, the cross-section of the permanent magnets should be rectangular. For example, there is a certain height difference between two adjacent permanent magnets in the same magnetic pole 30. This height difference specifically refers to the difference in the radial dimensions of the permanent magnets in the rotor core 20. Figure 3As shown, the magnetic pole 30 includes adjacent permanent magnets 31 and 32. The permanent magnet 31 includes a first end face 311 and a second end face 312 opposite to the first end face 311. The first end face 311 is connected to the attachment region 202, and the second end face 312 faces the stator 100. The permanent magnet 32 ​​includes a first end face 321 and a second end face 322 opposite to the first end face 321. The first end face 321 is connected to the attachment region 202, and the second end face 322 faces the stator 100. The height of permanent magnet 31 (i.e., the distance between the first end face 311 and the second end face 312) is d1, and the height of permanent magnet 32 ​​(i.e., the distance between the first end face 321 and the second end face 322) is d2. The difference between d2 and d1 is Δd, and Δd > 0. There is a certain height difference between the second end face 312 of permanent magnet 31 and the second end face 322 of permanent magnet 32, which is equivalent to forming a step structure on the magnetic pole 30. During the rotation of rotor 200, the above-mentioned step structure of magnetic pole 30 has the function of pumping air, driving the air flow between rotor 200 and stator 100, so that the flowing air can carry away the heat on the surface of magnetic pole 30 and enhance the natural cooling effect of permanent magnet synchronous motor.

[0031] In this invention, an adhesive layer is filled between the first end face of the permanent magnet and the attachment area 202. The permanent magnet and the attachment area 202 are bonded and fixed together by the adhesive layer. This adhesive fixing method facilitates the assembly of the permanent magnet and the rotor core 20, and allows for the bonding of a corresponding number of permanent magnets and permanent magnets of corresponding sizes and specifications to the attachment area 202 according to actual needs. The adhesive layer can be a glue containing glass beads, ensuring high bonding strength between the first end face of the permanent magnet and the attachment area 202 while ensuring insulation between the permanent magnet and the rotor core 20.

[0032] A gap is formed between two adjacent permanent magnets in the magnetic pole 30. The gap insulates and isolates the two adjacent permanent magnets. During assembly, two or more permanent magnets on the magnetic pole 30 are sequentially bonded to the attachment area 202. It is only necessary to control the spacing between the two adjacent permanent magnets to form the gap mentioned above. In this way, the magnetic pole 30 can be adapted according to actual needs.

[0033] In some preferred embodiments, an insulating layer can be filled in the gap between two adjacent permanent magnets. For example, insulating adhesive can be filled in the gap to insulate the two permanent magnets from each other while bonding and fixing them together. During assembly, the insulating adhesive can be used to bond two or more permanent magnets together to form magnetic poles 30, and then the magnetic poles 30 can be bonded to the attachment area 202. Alternatively, the surface of the permanent magnets can be insulated. For example, epoxy resin can be sprayed onto the surface of the permanent magnets to form an insulating wrapping layer attached to the outer surface of the permanent magnets. The insulating wrapping layer located on the side of the permanent magnets can be used to fill the gap between two adjacent permanent magnets. In addition to epoxy resin, other insulating materials can be used to cover the outer surface of the permanent magnets. During assembly, after covering the surface of a single permanent magnet with an insulating wrapping layer, two or more permanent magnets are bonded to the attachment area 202. Filling the gap between two adjacent permanent magnets with an insulating layer can effectively insulate and isolate the two adjacent permanent magnets while avoiding magnetic field interference between them, thereby improving the stability of the permanent magnet synchronous motor.

[0034] Adjacent permanent magnets of the same magnetic pole 30 are set to different widths; see details below. Figure 3 As shown, the permanent magnet 31 includes two opposing side surfaces 313, which are respectively connected between the two sides of the first end face 311 and the second end face 312. The two side surfaces 313, together with the first end face 311 and the second end face 312, form a rectangular cross-section for the permanent magnet 31. Similarly, the permanent magnet 32 ​​includes two opposing side surfaces 323, which are respectively connected between the two sides of the first end face 321 and the second end face 322. The two side surfaces 323, together with the first end face 321 and the second end face 322, form a rectangular cross-section for the permanent magnet 31. The width of the permanent magnet 31 (i.e., the distance between the two side surfaces 313) is W1, and the width of the permanent magnet 32 ​​(i.e., the distance between the two side surfaces 323) is W2, where W1 > W2, meaning the width of the permanent magnet 31 is greater than the width of the permanent magnet 32. Adjacent permanent magnets use different widths, and permanent magnets with different heights and widths are used at different pole arc positions to reduce the air gap magnetic flux density distortion and decrease the excitation of torque fluctuations.

[0035] In Embodiment 1 of this utility model, the magnetic pole 30 includes four permanent magnets, specifically two permanent magnets 31 and two permanent magnets 32. The height of the two permanent magnets 32 located in the middle of the magnetic pole 30 is greater than the height of the permanent magnets 31 located on both sides of the magnetic pole 30, so that the surface of the magnetic pole 30 forms a structure in which the middle protrudes away from the central axis of the rotor core 20. Of course, the two permanent magnets 32 can also be set as a whole, or a single permanent magnet 32 ​​can be set, so that the magnetic pole 30 includes three permanent magnets, which can also form a structure in which the middle of the magnetic pole 30 protrudes. Setting the surface of the magnetic pole 30 to have a structure in which the middle protrudes allows the magnetic pole 30 to smoothly agitate the airflow between the rotor 200 and the stator 100 when the magnetic pole 30 rotates with the rotor core 20, making the pumping effect of the magnetic pole 30 more obvious.

[0036] Figure 4 The rotor of Embodiment 2 of this utility model is shown, wherein the magnetic pole 30 includes two permanent magnets 33 and two permanent magnets 34. The two permanent magnets 34 are located in the middle of the magnetic pole 30, and the two permanent magnets 33 are located on both sides of the magnetic pole 30. The height of the two permanent magnets 34 in the middle is less than the height of the two permanent magnets 33 on both sides, thereby forming a structure in which the surface of the magnetic pole 30 is concave towards the central axis of the rotor core. Of course, the two permanent magnets 34 can also be set as a whole, or a single permanent magnet 34 can be used, so that the magnetic pole 30 includes three permanent magnets, which can also form a concave structure on the surface of the magnetic pole 30. With the surface of the magnetic pole 30 set as concave in the middle, as the magnetic pole 30 rotates with the rotor core, the airflow between the rotor 200 and the stator 100 can form vortices at the concave position in the middle of the magnetic pole 30, so that the air can more fully exchange heat with the surface of the magnetic pole 30, improving the natural cooling effect.

[0037] like Figure 5 As shown, this is the rotor of Embodiment 3 of the present invention. The magnetic poles include six permanent magnets, with three permanent magnets forming a group. The height of the three permanent magnets in each group increases sequentially along the circumference of the rotor core, creating at least two stepped structures on the surface of the magnetic poles. The magnetic poles utilize permanent magnets of multiple sizes and specifications, resulting in a stepped surface structure that further enhances the pumping and natural cooling effects of the magnetic poles. Furthermore, because the magnetic poles are composed of a greater number of permanent magnets, each permanent magnet has a smaller second end face, further reducing the induced eddy currents generated in the rotating magnetic field. In the rotor of this Embodiment 3, the height of the other group of three permanent magnets is arranged irregularly, causing the multiple permanent magnets on the magnetic poles to be asymmetrically distributed along the center of the pole.

[0038] Figure 6The rotor of Embodiment 4 of this utility model has six permanent magnets on the magnetic poles. Each group consists of three permanent magnets. The height of the three permanent magnets in each group gradually changes along the circumference of the rotor core, so that the multiple permanent magnets on the magnetic poles are arranged symmetrically along the center of the magnetic poles.

[0039] Figure 7 , 8 The present invention illustrates a rotor and a permanent magnet synchronous motor having the rotor according to Embodiment 5. The rotor includes a stator 400 and a rotor 500. The rotor 500 includes a rotor core 50 and a plurality of magnetic poles 60. The rotor core 50 is cylindrical, and its inner edge forms a circumferential mating surface. The stator 400 is placed inside the rotor core 50. The magnetic poles 60 include two or more permanent magnets. The size, specifications and arrangement of the two or more permanent magnets are the same as those in Embodiments 1 to 4 above, and will not be repeated here.

[0040] The permanent magnet synchronous motor of this invention includes the rotor described above. Other structures of the permanent magnet synchronous motor are the same as those in the prior art and will not be described in detail here.

[0041] Although only certain components and embodiments of this application have been illustrated and described, many modifications and alterations will be apparent to those skilled in the art without actually departing from the scope and spirit of the claims, such as variations in the size, dimensions, structure, shape and proportion of the various elements, installation arrangement, material use, color, orientation, etc.

[0042] The above embodiments are merely preferred embodiments of the present utility model and should not be construed as limiting the scope of protection of the present utility model. Any non-substantial changes and substitutions made by those skilled in the art based on the present utility model shall fall within the scope of protection claimed by the present utility model.

Claims

1. A rotor, cooperating with a stator, characterized in that It includes a rotor core and multiple magnetic poles. The rotor core has a circumferential mating surface opposite to the stator. Multiple attachment regions are formed on the circumferential mating surface, arranged in an array around the central axis of the rotor core. The multiple magnetic poles are placed on the multiple attachment regions one by one. The magnetic pole includes two or more permanent magnets arranged circumferentially along the rotor core. The cross-section of the permanent magnet is rectangular. The permanent magnet includes a first end face and a second end face opposite to the first end face. The first end face is directly opposite to the attachment region and connected to the attachment region.

2. The rotor of claim 1, wherein An adhesive layer is filled between the first end face of the permanent magnet and the attachment area, and the adhesive layer is used to fix the first end face of the permanent magnet and the attachment area together.

3. The rotor of claim 1, wherein A gap is formed between two adjacent permanent magnets in a magnetic pole to insulate and isolate the two adjacent permanent magnets.

4. The rotor of claim 3, wherein The gap is filled with an insulating layer, or the outer surface of the permanent magnet is covered with an insulating wrapping layer that fills the gap.

5. The rotor as claimed in claim 1, characterized in that, In two permanent magnets with the same magnetic pole that are adjacent to each other, the distance by which the second end face of one permanent magnet is offset from the second end face of the other permanent magnet in the direction away from the central axis of the rotor core is Δd, where Δd > 0.

6. The rotor as described in claim 1 or 5, characterized in that, The permanent magnet has two sides, which are respectively connected between the two sides of the first end face and the second end face. In two permanent magnets with the same magnetic pole, the distance between the two sides of one permanent magnet is W1, and the distance between the two sides of the other permanent magnet is W2, where W1 > W2.

7. The rotor as claimed in claim 1, characterized in that, The magnetic pole comprises three or more permanent magnets, with the height of the middle permanent magnet being greater than that of the two outer permanent magnets, so that the surface of the magnetic pole has a structure that is concave in the middle towards the central axis of the rotor core; or The magnetic pole comprises three or more permanent magnets, with the height of the middle permanent magnet being less than the height of the permanent magnets on both sides, so that the surface of the magnetic pole forms a structure that protrudes from the center axis away from the rotor core.

8. The rotor as claimed in claim 1, characterized in that, The magnetic pole comprises three or more permanent magnets, the height of which increases sequentially along the circumference of the rotor core, so that the surface of the magnetic pole forms at least two stepped structures.

9. A permanent magnet synchronous motor, characterized in that, It includes a stator and a rotor as described in any one of claims 1-8, wherein the rotor core is cylindrical, the circumferential mating surface is the outer edge surface of the rotor core, and the stator is arranged around the outer periphery of the rotor core.

10. A permanent magnet synchronous motor, characterized in that, It includes a stator and a rotor as described in any one of claims 1-8, wherein the rotor core is cylindrical, the circumferential mating surface is the inner edge surface of the rotor core, and the stator is placed inside the rotor core.

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