Stator structure of air-cooled island permanent magnet direct drive motor

Abstract

The utility model relates to motor technical field discloses a kind of air-cooled island permanent magnet direct drive motor stator structure, including stator core tooth part, stator core yoke part, stator magnetic slot, stator coil;The stator core tooth part is formed by laminating oriented silicon steel sheet, and the direction of silicon steel sheet is along the main magnetic flux direction generated by motor stator winding and rotor permanent magnet;The stator core yoke part is formed by laminating oriented silicon steel sheet, and the direction of silicon steel sheet is along the main magnetic flux direction generated by motor stator winding and rotor permanent magnet;The stator core tooth part and stator core yoke part are spliced to form motor stator core by dovetail groove structure;Complete motor stator core forms 48 stator magnetic slots, and stator coil is embedded in stator magnetic slot;The stator coil is formed by winding rare earth aluminium wire;The utility model stator core tooth part and yoke part are formed by laminating oriented silicon steel sheet, and stator winding is formed by rare earth aluminium wire simultaneously, and the effect of reducing motor weight and improving motor efficiency is realized simultaneously.

Description

Technical Field

[0001] This utility model relates to the field of multipole motor technology, and in particular to a stator structure for an air-cooled island permanent magnet direct drive motor. Background Technology

[0002] Air-cooled islands are widely used in thermal power plants, coal chemical industries, and other sectors, and are key equipment in high-energy-consuming fields. Addressing the unique operating conditions of air-cooled islands, such as low speed and high torque, high temperature, dust, and vibration, a dedicated permanent magnet direct-drive motor has been developed. This motor achieves direct coupling between the motor and the air-cooled island fan, meeting the requirements for efficient drive and stable operation. It replaces the traditional "asynchronous motor + reducer" system, reducing the energy consumption of the air-cooling system and decreasing carbon emissions.

[0003] Currently, the limited space in the steel frame of air-cooled islands and the weight of the original asynchronous motor + reducer represent the maximum weight limit for on-site hoisting of air-cooled islands. Therefore, the development challenges of permanent magnet direct drive motors for air-cooled islands lie in two aspects: high-efficiency motor design and lightweight motor design. Existing technologies for developing permanent magnet direct drive motors for air-cooled islands use non-oriented silicon steel sheets for the stator core. While this technology allows for on-site hoisting capacity, it limits the high-efficiency design; conversely, while meeting the high-efficiency design requirements, the overall motor weight exceeds the on-site hoisting capacity limit. Utility Model Content

[0004] The purpose of this utility model is to provide a stator structure for an air-cooled island permanent magnet direct drive motor, which effectively solves the problem mentioned in the background art that the stator core of the permanent magnet direct drive motor is manufactured by stacking non-oriented silicon steel sheets, which cannot achieve the design requirements of high efficiency and lightweight motor at the same time.

[0005] The technical solution adopted in this utility model is as follows: A stator structure for an air-cooled island permanent magnet direct-drive motor includes stator core teeth, a stator core yoke, stator magnetic slots, and stator coils. The stator core teeth are formed by stacking oriented silicon steel sheets, with the silicon steel sheets oriented along the direction of the main magnetic flux generated by the motor stator windings and the rotor permanent magnets. The stator core yoke is also formed by stacking oriented silicon steel sheets, with the silicon steel sheets oriented along the direction of the main magnetic flux generated by the motor stator windings and the rotor permanent magnets. The stator core teeth and the stator core yoke are joined together by a dovetail groove structure to form the motor stator core. The complete motor stator core forms 48 stator magnetic slots, in which stator coils are embedded. The stator coils are wound using rare-earth aluminum wire. Rare-earth aluminum wire is lighter and lower in cost than copper wire of the same specification, and has good ductility, making it suitable for complex coil formation.

[0006] It also includes stator end baffles for limiting the stator core of the motor, with 48 stator end baffles forming a ring; the complete ring stator end baffle is positioned by 4 arc-shaped pressure plates, the end face of the arc-shaped pressure plates has positioning bosses corresponding to the stator end baffles, and the gap between adjacent positioning bosses forms a wire passage corresponding to the stator magnetic slot; the arc-shaped pressure plates are engaged with the stator limiting ring of the motor housing.

[0007] The stator core yoke is joined to the inner wall of the motor housing by a concave-convex structure.

[0008] The inner wall of the stator limiting ring has 48 first wedge grooves, and a radial locking pin is slidably connected in the first wedge groove; the radial locking pin causes the arc-shaped pressure plate to clamp the motor stator core inward; the tail of the radial locking pin has a striking end.

[0009] The outer wall of the arc-shaped pressure plate has a guide groove; the side wall of the radial locking pin has an anti-rotation guide post that matches the guide groove.

[0010] The beneficial effects of this utility model are as follows: Compared with the prior art, the weight of the motor is reduced by about 40% under the same specifications and performance parameters (such as rated power, rated speed, rated efficiency, rated power factor, maximum torque multiple, etc.). The grains of oriented silicon steel are regularly arranged along the rolling direction, resulting in extremely high permeability in the rolling direction. Under the same magnetic field, the magnetic flux density B is much greater than that of non-oriented silicon steel; while the grains of non-oriented silicon steel are randomly distributed, with uniform permeability in all directions, but the overall permeability is lower. With the same core size, oriented silicon steel can carry a larger magnetic flux, requiring a smaller core cross-sectional area for the motor, which directly reduces the overall size of the machine. For example, the magnetic polarization intensity of 50DW600 non-oriented silicon steel sheet is 1.68T, while that of oriented silicon steel sheet of the same specification is 2.03T, an increase of 20.83%. Under the premise of constant output power, the larger the core magnetic flux density B, the smaller the required core cross-sectional area S and core length Ln can be. After the core size is compressed, the stator frame and the outer shell are reduced in size, and the weight and volume of the whole machine are reduced. Attached Figure Description

[0011] Figure 1 This is a diagram of the stator core of a permanent magnet direct drive motor.

[0012] Figure 2 This is a partial view of the stator core of a permanent magnet direct drive motor.

[0013] Figure 3 This is a partial view of the stator core teeth and yoke.

[0014] Figure 4 This is a schematic diagram showing the magnetic flux direction distribution of the stator teeth and yoke of a permanent magnet direct drive motor.

[0015] Figure 5This is a three-dimensional structural diagram of the stator end baffle.

[0016] Figure 6 This is a three-dimensional structural diagram of the stator limiting ring.

[0017] Figure 7 This is a schematic diagram of the main structure of the arc-shaped pressure plate.

[0018] Figure 8 This is a side cross-sectional view of the radial locking pin.

[0019] Figure 9 This is a three-dimensional structural diagram of the guide groove.

[0020] Figure 10 A schematic diagram of the three-dimensional structure of the guide post.

[0021] Figure 11 This is a diagram showing the magnetic flux distribution of the stator teeth and yoke of a permanent magnet direct drive motor.

[0022] In the diagram: 1. Stator core teeth; 2. Stator core yoke; 3. Stator magnetic slot; 4. Stator coil; 5. Dovetail groove structure; 6. Stator end baffle; 7. Arc-shaped pressure plate; 8. Positioning boss; 9. Wire through hole; 10. Motor housing; 11. Stator limiting ring; 12. Concave-convex structure; 13. First wedge groove; 14. Radial locking pin; 15. Striking end; 16. Guide groove; 17. Anti-rotation guide post. Detailed Implementation

[0023] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings. The following description is only used to illustrate the technical solution of this utility model and is not intended to limit it.

[0024] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "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. They are only for the convenience of describing this utility model 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. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0025] like Figure 1-3 As shown, a stator structure for an air-cooled island permanent magnet direct drive motor includes a stator core tooth section 1, a stator core yoke section 2, a stator magnetic slot 3, and a stator coil 4. The stator core tooth section 1 and the stator core yoke section 2 are spliced ​​together by a dovetail groove structure 5 to form the motor stator core. The overall structure is compact, has high assembly precision, and strong structural stability, and can be adapted to the working environment of long-term continuous operation and slight vibration of the air-cooled island fan.

[0026] In this embodiment, both the stator core tooth section 1 and the stator core yoke section 2 are made of V27QH120 grade oriented silicon steel sheets, which differs from the single non-oriented silicon steel sheet material of traditional motors, thus optimizing the magnetic conductivity of the core from the material source. The V27QH120 grade oriented silicon steel sheets are commercially available oriented electrical steel products, which can be directly purchased by those skilled in the art through conventional commercial channels such as silicon steel manufacturers (Baosteel, Wuhan Iron and Steel Co., Ltd.), Shougang Zhixin Electromagnetic, Wangbian Electric, Baotou Weifeng, steel trading distributors, and online metal material procurement platforms.

[0027] like Figure 4 As shown, in this embodiment, in the direction of the oriented silicon steel sheet arrangement, the oriented silicon steel sheet direction of the stator core teeth 1 and the stator core yoke 2 is along the direction of the main magnetic flux generated by the coupling between the motor stator winding and the rotor permanent magnet. Two adjacent stator core teeth 1 are made by splicing silicon steel sheets with opposite rolling directions, and two adjacent stator core yokes 2 are made by splicing silicon steel sheets with opposite rolling directions. Figure 11 As shown, the magnetic flux flows in opposite directions between adjacent stator teeth. The magnetic flux inside tooth 1 is arranged from the tooth tip to the tooth root, and the magnetic flux of the corresponding yoke segment of tooth 1 is tangentially to the left along the circumference. The magnetic flux inside adjacent tooth 2 is arranged from the tooth root to the tooth tip, and the magnetic flux of the corresponding yoke segment of tooth 2 is tangentially to the right along the circumference. The rolling direction of the oriented silicon steel sheet used in the stator core tooth 1 is consistent with the radial magnetic flux direction of the tooth, and the rolling direction of the oriented silicon steel sheet used in the stator core yoke 2 is consistent with the tangential magnetic flux direction of the yoke. This embodiment of the permanent magnet direct drive motor utilizes the alternating magnetic flux flow characteristics of adjacent stator teeth. It separates and cuts grain-oriented silicon steel sheets into the tooth and yoke sections, arranging them in corresponding rolling directions. This overcomes the limitation of whole-round stamped grain-oriented silicon steel, which only has a single rolling direction and cannot adapt to the radial and circumferential orthogonal magnetic flux of the stator. Leveraging the high permeability and low iron loss of grain-oriented silicon steel during rolling, it reduces the alternating loss of the stator core and improves the overall operating efficiency of the permanent magnet direct drive motor. The grains of the grain-oriented silicon steel sheets are regularly arranged along the rolling direction, and the permeability in the rolling direction is much higher than that of non-oriented silicon steel sheets. The magnetic polarization intensity can reach 2.03T, which is 20.83% higher than the 1.68T magnetic polarization intensity of conventional 50DW600 non-oriented silicon steel sheets, significantly improving the magnetic flux carrying capacity of the core.

[0028] In this embodiment, the motor stator core adopts a split splicing structure, specifically including 48 trapezoidal stator core teeth 1 and 48 stator core yokes 2, with each set of teeth and yokes corresponding one-to-one. The mating ends of the stator core teeth 1 and yokes are equipped with matching dovetail groove structures 5, which are then joined together to form a complete annular stator core. Compared to a monolithic core, the split dovetail groove splicing structure not only reduces processing difficulty and increases stacking accuracy, but also effectively avoids the problems of stress concentration and uneven magnetic conductivity during stamping of a monolithic core, further ensuring stable motor operation.

[0029] In this embodiment, the complete annular stator core forms 48 stator magnetic slots 3. The slot shape is adapted to the concentrated winding process, providing a precise mounting position for the stator coil 4, ensuring uniform winding arrangement and symmetrical magnetic field distribution.

[0030] In this embodiment, the stator coil 4 is embedded inside the stator magnetic slot 3. The stator coil 4 is formed by flat winding of rare-earth aluminum wire and adopts a concentrated winding structure. Rare-earth aluminum wire has excellent ductility and formability, which can perfectly adapt to the complex slot winding forming requirements of air-cooled island motors, resulting in high winding fit and stable winding fill factor. At the same time, compared with traditional pure copper wire of the same specification, rare-earth aluminum wire has significantly reduced weight, lower cost, and conductivity that meets the rated operating requirements of the motor.

[0031] In this embodiment, the motor is a 40-pole, 48-slot low-speed direct-drive structure, suitable for the low-speed, high-torque operation requirements of air-cooled island fans. After assembly, the stator core teeth 1 and stator core yoke 2 corresponding to each stator magnetic slot 3 are magnetically guided along the main magnetic flux direction. The magnetic flux directions of two adjacent stator core teeth 1 are opposite, and the magnetic flux directions of two adjacent stator core yoke 2 are also arranged in opposite directions. The overall magnetic field distribution is uniform and the magnetic flux loss is small, effectively reducing the iron loss of the motor and improving the motor's operating efficiency.

[0032] like Figure 5-7 As shown, in this embodiment, a stator end baffle 6 for limiting the stator core of the motor is also included. 48 stator end baffles 6 form a ring. The shape of the stator end baffle 6 is convex. The lower part of the stator end baffle 6 is adapted to the yoke part 2 of the stator core, and the upper part of the stator end baffle 6 is adapted to the tooth part 1 of the stator core. The complete annular stator end baffle 6 is positioned by 4 arc-shaped pressure plates 7. The end face of the arc-shaped pressure plate 7 has a positioning boss 8 corresponding to the stator end baffle 6. The upper edge of the positioning boss 8 is lower than the upper edge of the stator end baffle 6. The gap between adjacent positioning bosses 8 forms a wire passage 9 corresponding to the stator magnetic groove 3. The angle between the positioning boss 8 and the arc-shaped pressure plate 7 is a rounded corner structure. The arc-shaped pressure plate 7 is engaged with the stator limiting ring 11 of the motor housing 10.

[0033] In this embodiment, the stator core yoke 2 and the inner wall of the motor housing 10 are spliced ​​together by the concave-convex structure 12.

[0034] like Figure 8 As shown, in this embodiment, the inner wall of the stator limiting ring 11 has 48 first wedge-shaped grooves 13, and a radial locking pin 14 is slidably connected in the first wedge-shaped groove 13. The radial locking pin 14 is trapezoidal in shape, and the inclined surface of the radial locking pin 14 is located on one side of the contact surface with the stator limiting ring 11. The radial locking pin 14 causes the arc-shaped pressure plate 7 to clamp the motor stator core inward. The tail of the radial locking pin 14 has a striking end 15, which is located outside the first wedge-shaped groove 13.

[0035] like Figure 9 and 10 As shown, in this embodiment, the outer wall of the arc-shaped pressure plate 7 has a guide groove 16, and the guide groove 16 is semi-circular in shape; the side wall of the radial locking pin 14 has an anti-rotation guide post 17 adapted to the guide groove 16. By setting the anti-rotation guide post 17, the arc-shaped pressure plate 7 can be prevented from deflecting along the inner wall of the housing.

[0036] Test data of the prototype air-cooled island permanent magnet direct drive motor: rated power 110kW, rated voltage 380V, rated speed 77r / min, rated efficiency 95%, weight 1.7T.

[0037] Table 1. Main Design Parameters and Performance Indicators of Motors with Different Silicon Steel Sheet Stator Structures

[0038] The comparison shows that, under the premise that the stator outer diameter, motor rated power and rated speed are exactly the same, this embodiment significantly shortens the core length by optimizing the core material, winding material and structural layout, reducing the overall weight by 39.29%, while increasing the motor rated efficiency by 0.9%, effectively reducing the motor's operating energy consumption.

[0039] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A stator structure for an air-cooled island permanent magnet direct drive motor, comprising a stator core tooth section (1), a stator core yoke section (2), a stator magnetic slot (3), and a stator coil (4), characterized in that, The stator core teeth (1) and stator core yoke (2) are spliced ​​together by a dovetail groove structure (5) to form an annular stator core; the stator core teeth (1) and stator core yoke (2) are both made of oriented silicon steel sheets stacked together, and the rolling direction of the oriented silicon steel sheets is arranged along the direction of the main magnetic flux generated by the coupling between the motor stator winding and the rotor permanent magnet; the annular stator core has 48 stator magnetic slots (3), and the slot shape of the stator magnetic slots (3) is adapted to the concentrated winding; the stator coil (4) is embedded in the stator magnetic slots (3) and adopts a concentrated winding structure, and the stator coil (4) is formed by flat winding of rare earth aluminum wire.

2. The stator structure of the air-cooled island permanent magnet direct drive motor according to claim 1, characterized in that, The oriented silicon steel sheet is a V27QH120 grade silicon steel sheet.

3. The stator structure of the air-cooled island permanent magnet direct drive motor according to claim 1, characterized in that, The stator core teeth (1) and stator core yoke (2) are each 48 pieces, with each set of teeth and yoke corresponding to one another, and the stator core teeth (1) has a trapezoidal structure.

4. The stator structure of the air-cooled island permanent magnet direct drive motor according to claim 1, characterized in that: The two adjacent stator core teeth (1) are made of silicon steel sheets with opposite rolling directions spliced ​​together, and the two adjacent stator core yokes (2) are made of silicon steel sheets with opposite rolling directions spliced ​​together.

5. The stator structure of the air-cooled island permanent magnet direct drive motor according to any one of claims 1 to 4, characterized in that, It also includes 48 stator end baffles (6), which are arranged in a ring. The stator end baffles (6) are convex in shape, with their lower part adapted to the stator core yoke (2) and their upper part adapted to the stator core tooth (1).

6. The stator structure of the air-cooled island permanent magnet direct drive motor according to claim 5, characterized in that, It also includes 4 arc-shaped pressure plates (7) for positioning the annular stator end baffle (6). The end face of the arc-shaped pressure plate (7) has a positioning boss (8) corresponding to the stator end baffle (6). The gap between adjacent positioning bosses (8) forms a wire passage (9) corresponding to the stator magnetic groove (3). The arc-shaped pressure plate (7) is engaged with the stator limiting ring (11) of the motor housing (10).

7. The stator structure of the air-cooled island permanent magnet direct drive motor according to claim 6, characterized in that, The stator core yoke (2) is joined to the inner wall of the motor housing (10) by a concave-convex structure (12).

8. The stator structure of the air-cooled island permanent magnet direct drive motor according to claim 6, characterized in that, The inner wall of the stator limiting ring (11) is provided with 48 first wedge grooves (13), and a radial locking pin (14) is slidably connected in each first wedge groove (13). The radial locking pin (14) is trapezoidal in shape. The radial locking pin (14) is used to drive the arc-shaped pressure plate (7) to clamp the annular stator core inward. The tail of the radial locking pin (14) has a striking end (15).

9. The stator structure of the air-cooled island permanent magnet direct drive motor according to claim 8, characterized in that, The outer wall of the arc-shaped pressure plate (7) has a semi-circular guide groove (16), and the side wall of the radial locking pin (14) has an anti-rotation guide post (17) adapted to the guide groove (16).

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