Surface-mounted rotor and permanent magnet synchronous motor

Abstract

The utility model discloses a surface mount type rotor and permanent magnet synchronous motor, surface mount type rotor and stator cooperation, it includes rotor core, a plurality of permanent magnet, be provided with the circumference cooperation surface with stator on rotor core, be provided with a plurality of installation recess on the circumference cooperation surface, the portion of rotor core between two adjacent installation recess forms a stopper, the cross section of permanent magnet is rectangular, and it includes two end faces and two lateral surface, a plurality of permanent magnet is embedded in a plurality of installation recesses one by one to make a plurality of permanent magnet and rotor core fixed cooperation, the distance between two lateral surface of permanent magnet is greater than the depth of installation recess, and two adjacent permanent magnet and stopper jointly enclose a recess position. The utility model discloses utilize installation recess to position permanent magnet, improved the installation precision of permanent magnet on rotor core, avoided the pole arc coefficient deviation, improved the consistency of motor performance, promoted the cooling effect of permanent magnet synchronous motor simultaneously.

Description

Technical Field

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

[0002] With the continuous development of electric drive technology, permanent magnet synchronous motors are widely used in the joint drive components of humanoid robots. Currently, most permanent magnet synchronous motors used in humanoid robots employ surface-mount rotors, where permanent magnets are glued to the surface of the rotor core to form the rotor. The permanent magnets provide a magnetic field for the rotor, and the interaction between the stator and rotor magnetic fields generates torque, driving the rotor to rotate. In existing surface-mount rotors, the permanent magnets, acting as magnetic poles, are directly glued to the outer circumference of the rotor core. Since the outer circumference of the rotor core is circular, the location where the permanent magnets are glued to the rotor core needs to be planar. When the plane is glued to the permanent magnet, it is impossible to position the permanent magnet, especially in the circumferential direction of the rotor core. This makes it difficult to guarantee the assembly accuracy of the permanent magnets and the rotor core, resulting in a large deviation in the pole arc coefficient of the rotor. 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 surface-mounted rotor and a permanent magnet synchronous motor to solve the problems of poor assembly accuracy of permanent magnets and rotor cores and large deviation of rotor pole arc coefficient in the prior art.

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

[0005] The surface-mounted rotor, which mates with the stator, includes a rotor core and multiple permanent magnets. The rotor core has a circumferential mating surface opposite the stator, and multiple recessed mounting grooves on the circumferential mating surface, extending away from the stator. A stop block is formed on the rotor core between two adjacent mounting grooves. Each permanent magnet has a rectangular cross-section, including two opposite end faces and two opposite side faces. Multiple permanent magnets are correspondingly embedded in the mounting grooves to fix them to the rotor core. The distance between the two side faces of the permanent magnets is greater than the depth of the mounting grooves, causing the side of the permanent magnet closest to the stator to protrude beyond the end face of the stop block facing the stator. Two adjacent permanent magnets and the stop block together form a recess.

[0006] According to the surface-mounted rotor of this utility model embodiment, the permanent magnet is positioned by using the mounting groove provided on the rotor core, which improves the installation accuracy of the permanent magnet on the rotor core, avoids the deviation of the pole arc coefficient, and improves the consistency of motor performance. Adjacent permanent magnets and the stop block form a recess with an opening facing the stator. When the surface-mounted rotor rotates, the uneven structure formed by the recess on the outer edge surface of the surface-mounted rotor has a pumping effect, which drives the air flow between the stator and the surface-mounted rotor, improves the natural cooling effect of the permanent magnet synchronous motor, and the recess can also provide space for heat dissipation oil, so that the heat dissipation oil flowing through the recess can exchange heat with the surface-mounted rotor to remove the heat generated inside the permanent magnet synchronous motor.

[0007] In a preferred embodiment, the side of the permanent magnet furthest from the stator and its two end faces are respectively bonded and fixed to the bottom wall and side walls of the mounting groove. Three faces of the permanent magnet are bonded to the inner wall of the mounting groove. While using the mounting groove to position the permanent magnet, this increases the bonding area between the permanent magnet and the rotor core, thus improving the firmness of the connection between the permanent magnet and the rotor core.

[0008] In a preferred embodiment, the stator is cylindrical, the rotor is placed inside the stator, the circumferential mating surface is the outer edge surface of the rotor core, and a fixed bushing is fitted on the outside of the rotor core. The fixed bushing wraps around the periphery of multiple permanent magnets and clamps the permanent magnets with the bottom wall of the mounting groove, thereby improving the firmness of the connection between the permanent magnets and the rotor core and simplifying the assembly process.

[0009] In a preferred embodiment, the permanent magnet is wrapped with an insulating layer, and adhesive layers covering the insulating layer are provided on the sides of the permanent magnet away from the stator and on the two end faces corresponding to the side walls of the mounting grooves. The insulating layer isolates the permanent magnet from the rotor core, preventing eddy currents from being generated in the rotor core by the alternating magnetic field, thereby reducing the temperature rise and energy loss of the permanent magnet synchronous motor.

[0010] In a preferred embodiment, the distance between the two end faces of the permanent magnet is W1, and the width of the stop is W2, where W1 / W2 is in the range of 2.8 to 3.7. In the circumferential direction of the rotor core, the permanent magnet has a relatively larger size than the stop, allowing it to have a relatively large cross-sectional area within a limited space, increasing the air gap magnetic flux and thus increasing the torque of the permanent magnet synchronous motor.

[0011] In a preferred embodiment, the distance between the two sides of the permanent magnet is D, and the depth of the mounting groove is H, where D / H is in the range of 1.5 to 3.3. While ensuring sufficient contact area between the end face of the permanent magnet and the sidewall of the mounting groove, the thickness of the permanent magnet and the height difference between the stop block are maximized, making the permanent magnet protrude sufficiently from the end face of the stop block. This, in turn, maximizes the depth of the recess 3, enhancing the pumping effect of the recess and further improving the cooling effect.

[0012] In a preferred embodiment, the rotor core includes multiple stacked rotor laminations, each lamination having multiple grooves. These grooves together form the mounting groove of the rotor core. The grooves can be pre-cut around the periphery of the rotor laminations using a stamping die, precisely machining the groove dimensions to achieve high precision in the mounting groove.

[0013] In a preferred embodiment, the rotor core is cylindrical, with a cavity inside that accommodates the stator, and the circumferential mating surface is the inner edge surface of the rotor core.

[0014] In a preferred embodiment, the permanent magnet comprises multiple permanent magnet units arranged circumferentially in the mounting groove along the rotor core. These permanent magnet units have a small surface area, resulting in smaller induced eddy currents in the rotating magnetic field, thus reducing the temperature rise and energy loss of the permanent magnet synchronous motor. Furthermore, the appropriate number and specifications of permanent magnet units can be selected to fill the mounting groove according to its actual dimensions, facilitating the assembly of the surface-mounted rotor.

[0015] Permanent magnet synchronous motors, including the surface-mounted rotors mentioned above.

[0016] 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

[0017] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present utility model;

[0018] Figure 2 for Figure 1 View from direction A;

[0019] Figure 3 for Figure 2 Enlarged view at point B;

[0020] Figure 4 This is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0021] Figure 5 for Figure 4 A magnified view at point C;

[0022] Figure 6 This is a structural schematic diagram of Embodiment 3 of the present invention.

[0023] In the diagram: 100, stator; 200, surface-mounted rotor; 20, rotor core; 21, mounting groove; 211, bottom wall; 212, side wall; 22, stop block; 221, end face; 23, recess; 30, permanent magnet; 31, side; 32, side; 33, end face; 40, fixing bushing; 500, stator; 600, surface-mounted rotor; 60, rotor core; 61, mounting groove; 62, stop block; 70, permanent magnet. Detailed Implementation

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] Figure 1 , 2 Figure 3 illustrates a surface-mount rotor 200 of this invention, which is applied to an electric motor, particularly a permanent magnet synchronous motor. The surface-mount rotor 200 mates with the stator 100 of the motor and includes a rotor core 20 and multiple permanent magnets 30. The stator 100 is cylindrical, forming a space in its middle to accommodate the surface-mount rotor 200. The outer edge of the rotor core 20 forms a circumferential mating surface opposite to the stator 100. Multiple mounting grooves 21 are provided on this circumferential mating surface. The mounting grooves 21 are recessed from the circumferential mating surface towards the inner side of the rotor core 20, i.e., the mounting grooves 21 are recessed from the circumferential mating surface towards the direction away from the stator 100. A stop block 22 is formed on the rotor core 20 between two adjacent mounting grooves 21. The permanent magnets 30 have a rectangular cross-section, including two opposing end faces 33, side faces 31, and side faces 32. Side faces 31 and 32 are opposite each other, and are connected by side faces 31. The permanent magnet 30 is formed into a rectangular structure that is easy to process by means of side 31 and side 32, and two end faces 33 connecting the two ends of side 31 and side 32. The cross-section of the permanent magnet 30 is rectangular. Multiple permanent magnets 30 are embedded in multiple mounting grooves 21 one by one. The mounting grooves 21 are used to position the permanent magnets 30 and fix the permanent magnets 30 to the rotor core 20. The distance between side 31 and side 32 of the permanent magnet 30 is greater than the depth of the mounting groove 21. After the permanent magnet 30 is placed in the mounting groove 21, the side 32 of the permanent magnet 30 near the stator 100 protrudes from the end face 221 of the stop block 22 facing the stator 100. Thus, two adjacent permanent magnets 30 and the stop block 22 together form a recess 23. Specifically, the recess 23 faces the stator 100 and is formed by two end faces 33 of two adjacent permanent magnets 30 that are close to each other and the end face 221 of the stop block 22.

[0029] In this invention, the permanent magnet 30 is positioned using the mounting groove 21 provided on the rotor core 20, which improves the installation accuracy of the permanent magnet 30 on the rotor core 20, avoids pole arc coefficient deviation, and improves the consistency of motor performance. The depth and other dimensions of the mounting groove 21 can be set according to the fixed position and thickness of the permanent magnet 30. In addition, adjacent permanent magnets 30 and the stop block 22 form a recess 23 with an opening facing the stator 100. When the surface-mounted rotor 200 rotates, the recess 23 is positioned on the surface. The uneven structure formed on the outer edge of the rotor 200 has a pumping effect, which drives the air flow between the stator 100 and the surface-mounted rotor 200, improving the natural cooling effect of the permanent magnet synchronous motor. The recess 23 can also provide space for the cooling oil, so that the cooling oil flowing through the recess 23 can exchange heat with the surface-mounted rotor 200 to remove the heat generated inside the permanent magnet synchronous motor. In short, the recess 23 formed by the adjacent permanent magnets 30 and the stop block 22 can improve the heat dissipation performance of the permanent magnet synchronous motor.

[0030] In this invention, the permanent magnet 30 can be fixed to the rotor core 20 by adhesive bonding. Specifically, the side 31 of the permanent magnet 30 is attached to and bonded to the bottom wall 211 of the mounting groove 21, and the two end faces 33 of the permanent magnet 30 are respectively attached to and bonded to the two side walls 212 of the mounting groove 21. In this way, three faces of the permanent magnet 30 are bonded to the inner wall of the mounting groove 21. While positioning the permanent magnet 30 using the mounting groove 21, the bonding area between the permanent magnet 30 and the rotor core 20 is increased, thereby improving the firmness of the connection between the permanent magnet 30 and the rotor core 20.

[0031] To further enhance the robustness of the connection between the permanent magnet 30 and the rotor core 20 and simplify the assembly process, a fixing bushing 40 is provided on the outside of the rotor core 20. This fixing bushing 40 wraps around the periphery of the permanent magnets 30, pressing them tightly against the outer edge. The fixing bushing 40 engages with the bottom wall 211 of the mounting groove 21 to clamp the permanent magnets 30, thus limiting their radial movement relative to the rotor core 20. In some embodiments, the permanent magnets 30 are fixed to the rotor core 20 only by adhesive bonding, or the fixing bushing 40 can be used to clamp them. Alternatively, after bonding the permanent magnets 30 to the rotor core 20, the fixing bushing 40 can be fitted onto the outside of the rotor core 20 to clamp them, resulting in a more stable fit between the permanent magnets 30 and the rotor core 20.

[0032] The permanent magnet 30 is externally wrapped with an insulating layer. An adhesive layer covering the insulating layer is provided on the side 31 and two end faces 33 of the permanent magnet 30, corresponding to the two side walls 212 of the mounting groove 21. The insulating layer covering the permanent magnet 30 can be epoxy resin or other insulating materials. During assembly, epoxy resin is first applied to the outside of the permanent magnet 30 to form an insulating layer. Then, adhesive is applied to the corresponding positions on the side 31 and two end faces 33. The permanent magnet 30 is then inserted into the opening of the mounting groove 21, thus bonding and fixing the permanent magnet 30 within the mounting groove 21. The insulating layer isolates the permanent magnet 30 from the rotor core 20, preventing eddy currents from being generated in the rotor core 20 by the alternating magnetic field, thereby reducing the temperature rise and energy loss of the permanent magnet synchronous motor.

[0033] The distance between the two end faces 33 of the permanent magnet 30 is W1, and the width of the stop block 22 is W2, where W1 / W2 is in the range of 2.8 to 3.7, preferably 3.15. That is, in the circumferential direction of the rotor core 20, the permanent magnet 30 has a relatively larger size than the stop block 22, giving the permanent magnet 30 a relatively large cross-sectional area within a limited space. This is beneficial for increasing the air gap magnetic flux and thus increasing the torque of the permanent magnet synchronous motor.

[0034] The distance between the side surface 31 and the side surface 32 of the permanent magnet 30 is D, and the depth of the groove is H, wherein D / H is in the range of 1.5 to 3.3, preferably D / H is 3. Under the premise of ensuring that the end face 33 of the permanent magnet 30 has sufficient contact area with the side wall 212 of the mounting groove 21, the thickness of the permanent magnet 30 and the height difference of the stop block 22 are increased as much as possible, so that the size of the permanent magnet 30 protruding from the end face 221 of the stop block 22 is large enough, thereby increasing the depth of the recess 23 as much as possible, improving the pumping effect of the recess 23, and further improving the cooling effect.

[0035] The rotor core 20 includes multiple stacked rotor laminations. Each rotor lamination has multiple grooves along its periphery. These grooves, corresponding to each other, together form the mounting groove 21 of the rotor core 20. The grooves can be pre-cut from the periphery of the rotor laminations using a stamping die, precisely machining their dimensions to ensure high precision in the mounting groove 21. The groove size on the rotor laminations can be slightly larger than W1, allowing the permanent magnet 30 to be inserted into the mounting groove 21. The depth of the grooves on the rotor laminations can be controlled according to the thickness of the permanent magnet 30.

[0036] Figure 4 , 5This illustration shows a surface-mounted rotor and a permanent magnet synchronous motor according to Embodiment 2 of the present invention. The permanent magnet synchronous motor includes a surface-mounted rotor 600 and a stator 500. This permanent magnet synchronous motor is an external rotor motor. The rotor core 60 of the surface-mounted rotor 600 is cylindrical, and a cavity for accommodating the stator 500 is formed inside it. The circumferential mating surface is the inner edge surface of the rotor core 60. Multiple mounting grooves 61 arranged circumferentially on the inner edge surface of the rotor core 60 are provided. A stop block 62 is formed between adjacent mounting grooves 61. Multiple permanent magnets 70 of the surface-mounted rotor 600 are embedded in the multiple mounting grooves 61 one-to-one. The permanent magnets 70 protrude from the side facing the stator 500 from the stop block 62. The other structures of the surface-mounted rotor in this Embodiment 2 are the same as those in Embodiment 1 above, and will not be described in detail here.

[0037] Figure 6 The illustration shows a surface-mounted rotor according to Embodiment 3 of this utility model. Unlike Embodiments 1 and 2, the permanent magnets of the surface-mounted rotor comprise multiple permanent magnet units, which are arranged circumferentially in the mounting groove along the rotor core. These multiple permanent magnet units have a smaller surface area, resulting in less induced eddy currents in the rotating magnetic field, thus reducing the temperature rise and energy loss of the permanent magnet synchronous motor. Furthermore, the appropriate number and specifications of permanent magnet units can be selected to fill the mounting groove according to its actual dimensions, facilitating the assembly of the surface-mounted rotor.

[0038] The permanent magnet synchronous motor of this invention includes the surface-mounted 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.

[0039] 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.

[0040] 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 surface-mounted rotor, fitted to a stator, characterized in that, It includes a rotor core and multiple permanent magnets; the rotor core has a circumferential mating surface opposite to the stator, and multiple mounting grooves recessed in the direction away from the stator are provided on the circumferential mating surface. The part of the rotor core located between two adjacent mounting grooves forms a stop block; the cross-section of the permanent magnet is rectangular, which includes two opposite end faces and two opposite side faces. Multiple permanent magnets are embedded in multiple mounting grooves one by one to fix the multiple permanent magnets with the rotor core. The distance between the two side faces of the permanent magnet is greater than the depth of the mounting groove so that the side of the permanent magnet close to the stator protrudes from the end face of the stop block facing the stator. Two adjacent permanent magnets and the stop block together form a recess.

2. The surface-mounted rotor as described in claim 1, characterized in that, The permanent magnet is bonded and fixed to the bottom and side walls of the mounting groove on the side away from the stator and the two end faces, respectively.

3. The surface-mounted rotor as described in claim 1 or 2, characterized in that, The stator is cylindrical, and the rotor is placed inside the stator. The circumferential mating surface is the outer edge surface of the rotor core. A fixed bushing is fitted on the outside of the rotor core. The fixed bushing wraps around the periphery of multiple permanent magnets and clamps the permanent magnets with the bottom wall of the mounting groove.

4. The surface-mounted rotor as described in claim 2, characterized in that, The permanent magnet is wrapped with an insulating layer. An adhesive layer covering the insulating layer is provided on the side of the permanent magnet away from the stator and on the two end faces corresponding to the mounting grooves on both sides.

5. The surface-mounted rotor as described in claim 1, characterized in that, The distance between the two ends of the permanent magnet is W1, and the width of the stop is W2, where W1 / W2 is in the range of 2.8 to 3.

7.

6. The surface-mounted rotor as described in claim 1, characterized in that, The distance between the two sides of the permanent magnet is D, and the depth of the mounting groove is H, where D / H is in the range of 1.5 to 3.

3.

7. The surface-mounted rotor as described in claim 1, characterized in that, The rotor core consists of multiple stacked rotor laminations, each lamination having multiple grooves. These grooves together form the mounting grooves of the rotor core.

8. The surface-mounted rotor as described in claim 1 or 2, characterized in that, The rotor core is cylindrical, and its interior forms a cavity to accommodate the stator. The circumferential mating surface is the inner edge surface of the rotor core.

9. The surface-mounted rotor as described in claim 1, characterized in that, The permanent magnet comprises multiple permanent magnet units, which are arranged circumferentially in the mounting groove along the rotor core.

10. A permanent magnet synchronous motor, characterized in that, Includes the surface-mounted rotor as described in any one of claims 1-9.

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