Air-cooled high-efficiency permanent magnet motor
Patent Information
- Application Number
- CN202522265213.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-27
- Publication Date
- 2026-09-18
- Estimated Expiration
- 2035-10-27
AI Technical Summary
[0003]目前，热电厂空冷系统中主流采用的驱动设备为励磁电机，这类电机在热电厂实际运行场景中存在以下不足，难以满足热电厂对高效节能、稳定运维的需求：一是励磁电机损耗产热多，而散热有限，温升又加剧损耗，反过来又导致效率降低，影响电机长期稳定运行；二是励磁电机自身低速扭矩输出能力不足，需连接减速机驱动空冷风扇，传动损耗较高，导致能耗提升；三是由于空冷设备通常布置在约40米高的桁架结构上，而增加减速机后设备、零部件增多，设备冗余且布置难度大，且存在运行中振动大等安全隐患问题
本实用新型提供了一种空冷高效永磁电机，在转子铁芯的磁钢槽内嵌装永磁铁，在转子铁芯的线槽内绕设励磁线圈，形成了永磁体和励磁绕组均置于转子上的混合电机，能够在较宽的速度范围内提供稳定的扭矩输出，磁阻损耗小、效率更高。在热电厂空冷岛风机中使用本空冷高效永磁电机后，无需连接减速机，电机可以直接连接驱动空冷风扇，进一步减少能耗、提升效率。
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Figure CN224774750U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of motor technology, specifically relating to an air-cooled high-efficiency permanent magnet motor. Background Technology
[0002] In the daily operation of a combined heat and power (CHP) plant, the air-cooling system is a key piece of equipment ensuring steam circulation and power generation efficiency. It drives air-cooled fans to forcibly cool the exhaust steam from the turbine, condensing it into water which is then returned to the boiler for recycling. Especially in CHP plants in water-scarce regions, the air-cooling system is a core device that replaces traditional water cooling and reduces water consumption. The drive motor of the air-cooled fan, as the power core of the air-cooling system, directly affects the steam circulation efficiency, plant power consumption, and operation and maintenance costs of the CHP plant.
[0003] Currently, the mainstream drive equipment used in the air-cooled systems of thermal power plants is the excitation motor. However, this type of motor has the following shortcomings in actual power plant operation, making it difficult to meet the demands for high efficiency, energy saving, and stable operation and maintenance: First, the excitation motor generates a lot of heat through losses, while heat dissipation is limited. The temperature rise further exacerbates the losses, leading to reduced efficiency and affecting the long-term stable operation of the motor. Second, the excitation motor itself has insufficient low-speed torque output capability, requiring a gearbox to drive the air-cooled fan, resulting in higher transmission losses and increased energy consumption. Third, since air-cooled equipment is usually installed on a truss structure approximately 40 meters high, adding a gearbox increases the number of equipment and components, leading to equipment redundancy, greater installation difficulty, and safety hazards such as significant vibration during operation. Therefore, for the purposes of energy saving, efficiency improvement, and stable and safe system operation, a new type of air-cooled motor is being developed. Summary of the Invention
[0004] The purpose of this invention is to provide an air-cooled, high-efficiency permanent magnet motor with stable torque output, strong heat dissipation and cooling capacity, small size, and high efficiency, which can solve all or part of the technical problems mentioned in the background art.
[0005] This utility model is implemented by the following technical solution: An air-cooled, high-efficiency permanent magnet motor, comprising: Shaft; Rotor assembly; the rotor assembly includes a rotor core, which is sleeved and fixed to the middle of the rotating shaft; Stator assembly; the stator assembly includes a stator core and a stator winding, the stator core is formed by stacking multiple silicon steel sheets, the stator core is disposed outside the rotor core; a first slot is formed on the side of the stator core near the rotor assembly, and the stator winding is wound in the first slot; Motor housing; the motor housing is fitted onto the outside of the stator assembly, and the inner wall of the motor housing is in contact with the outer wall of the stator core; A front cover and a rear cover; the front cover and the rear cover are respectively fixed to both ends of the motor housing, and the front cover and the rear cover are respectively rotatably connected to the rotating shaft; The rotor core has several magnetic slots, several sets of second wire slots, and several cooling slots sequentially formed along its circumference from the outside to the inside. Each magnetic slot contains a permanent magnet, arranged sequentially as N pole, S pole, N pole, ..., S pole. Each set of second wire slots contains two slots in which the excitation coil is wound. This forms a hybrid motor where both the permanent magnet and the excitation winding are located on the rotor. In this structure, the permanent magnet circuit and the electrically excited magnetic circuit are connected in parallel, and the electrically excited magnetic flux path does not pass through the permanent magnet, thus improving the motor's magnetic flux density. This motor features adjustable performance. It utilizes permanent magnet materials to generate a basic air gap magnetic field, and adjusts the magnetic field strength and direction through an additional electrically excited winding. This allows for flexible control of the motor's performance. When the motor's output power needs to be increased, the excitation coil is energized, which enhances the magnetism of the magnet, thereby generating greater torque in the rotor. Therefore, it can provide stable torque output over a wide speed range. Compared to traditional excitation motors, this structure has lower magnetic reluctance loss and higher efficiency. It does not require a speed reducer and can directly drive an air-cooled fan, eliminating the need for a speed reducer, reducing energy consumption, and further improving operating efficiency. The front cover has several air inlet holes along its circumference, and the rear cover has several air outlet holes along its circumference. An air inlet hood is provided on the side of the front cover away from the rear cover, and several ventilation openings are provided on the side wall of the air inlet hood. A guide plate is provided on the front cover between the air inlet holes and the air inlet hood, and a cooling fan is provided on the side of the guide plate near the ventilation openings. The rotor is cooled using a bladeless cooling method. The ventilation opening, air inlet, cooling groove, and air outlet are interconnected to form a cooling channel. During motor operation, airflow enters the air inlet shroud through the ventilation opening under the action of the cooling fan, then is guided by the guide plate, enters the internal cavity of the motor through the air inlet, passes through the cooling groove, and finally is blown out through the air outlet. This air cooling reduces the temperature inside the motor, especially the rotor, thus improving heat dissipation. This helps reduce losses, improve efficiency, extend the life of the permanent magnet, and alleviate the problems mentioned in the background art, such as the impact of temperature rise on the long-term stable operation of the motor. Furthermore, compared with liquid cooling, oil cooling, and other cooling methods, the above cooling method has a simpler structure, lower energy consumption, and lower cost.
[0006] Furthermore, the outer peripheral wall of the motor housing is provided with several axially extending heat dissipation fins, and each heat dissipation fin is equipped with several sets of heat dissipation fins, which helps to increase the heat dissipation area, improve heat dissipation efficiency, and thus alleviate the temperature rise of the motor.
[0007] Furthermore, magnetic deflection slots (also known as magnetic resistance slots, air magnetic isolation slots, etc.) are formed on the outer peripheral sidewall of the rotor core. The magnetic deflection slots are located between the two magnetic steel slots to reduce magnetic loss and further improve efficiency. The magnetic steel slots, the second wire slots, the cooling slots, and the magnetic deflection slots all extend along the axial direction of the rotor core. The number of sets of the second wire slots and the number of cooling slots are the same as the number of magnetic steel slots and correspond one-to-one.
[0008] Furthermore, the circles formed by all the air inlets, all the air outlets, and all the cooling grooves have the same radius and their centers are all located on the axis of the rotating shaft. The cooling channels thus formed allow cold air to flow and cool the inside of the motor, resulting in high cooling efficiency.
[0009] Furthermore, the cooling fan includes an annular fan shaft; an annular groove is provided on the front end cover between the guide plate and the air inlet shroud, and a plurality of coils are disposed in the annular groove; a plurality of grooves are provided at the bottom of the annular fan shaft, and permanent magnets are embedded in the grooves; the bottom of the annular fan shaft is slidably connected to the coils; a plurality of fan blades are provided on the side of the annular fan shaft away from the guide plate.
[0010] Beneficial effects: This invention provides an air-cooled, high-efficiency permanent magnet motor. Permanent magnets are embedded in the magnetic slots of the rotor core, and excitation coils are wound in the wire slots of the rotor core, forming a hybrid motor where both the permanent magnets and excitation windings are located on the rotor. This results in a stable torque output over a wide speed range, with low magnetic reluctance loss and higher efficiency. When this air-cooled, high-efficiency permanent magnet motor is used in the air-cooled island fans of thermal power plants, a speed reducer is eliminated, and the motor can be directly connected to drive the air-cooled fan, further reducing energy consumption and improving efficiency.
[0011] Cooling grooves are opened in the rotor core, an air inlet shroud and air inlet holes are set in the front end cover, and an air outlet hole is set in the rear end cover to form a wind-cooled cooling channel. During the operation of the motor, cold air forms an airflow through the cooling channel under the action of the cooling fan, which can better play the role of heat dissipation, which is conducive to reducing losses, improving efficiency, and extending the life of permanent magnets. Attached Figure Description
[0012] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0013] Figure 1This is a schematic diagram of the overall structure of the air-cooled high-efficiency permanent magnet motor of this utility model. Figure 2 This is a schematic diagram of an air-cooled high-efficiency permanent magnet motor. Figure 3 for Figure 2 AA cross-section view; Figure 4 for Figure 2 BB cross-section; Figure 5 for Figure 2 A left-to-right view of an air-cooled, high-efficiency permanent magnet motor. Figure 6 This is a structural diagram of the motor housing, heat dissipation fins, and rear end cover. Figure 7 This is a structural diagram of the motor housing, heat dissipation fins, heat dissipation plates, stator assembly, and rear end cover. Figure 8 This is a schematic diagram of the rotating shaft. Figure 9 This is a schematic diagram of the rotor core structure; Figure 10 This is a schematic diagram of the radial cross-section of the rotor core; Figure 11 A schematic diagram of the connection structure of the rotating shaft, rotor core, front end cover, and air inlet shroud; Figure 12 This is a cross-sectional schematic diagram of the front cover, air inlet shroud, and cooling fan; Figure 13 A schematic diagram of the cooling fan from one perspective; Figure 14 This is a structural schematic diagram of a cooling fan from another perspective.
[0014] The attached diagram is described below: 1. Shaft; 2. Rotor core; 21. Magnet slot; 22. Second slot; 23. Cooling slot; 24. Magnetic break slot; 3. Stator core; 31. First slot; 4. Motor housing; 41. Heat dissipation fins; 42. Heat dissipation fins; 5. Front cover; 51. Air inlet; 6. Rear cover; 61. Air outlet; 7. Air inlet shroud; 71. Ventilation opening; 8. Guide plate; 9. Cooling fan; 91. Annular fan shaft; 92. Coil; 93. Groove; 94. Fan blade. Detailed Implementation
[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. In the description of the present utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "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 the present 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, and therefore should not be construed as a limitation of the present 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. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0016] Example An air-cooled, high-efficiency permanent magnet motor, such as Figures 1-14 As shown, it includes a rotating shaft 1, a rotor assembly, a stator assembly, a motor housing 4, a front cover 5, a rear cover 6, and an air inlet shroud 7.
[0017] The rotor assembly includes a rotor core 2, which is fixed to the middle of the rotating shaft 1. Along the circumferential direction, the rotor core 2 has several magnetic slots 21, several sets of second wire slots 22, and several cooling slots 23 sequentially formed from the outside to the inside. Each magnetic slot 21 contains a permanent magnet, and each set of second wire slots 22 contains an excitation coil. Magnetic break slots 24 are formed on the outer circumferential sidewall of the rotor core 2, located between two magnetic slots 21. The magnetic slots 21, second wire slots 22, cooling slots 23, and magnetic break slots 24 all extend axially along the rotor core 2. The number of sets of second wire slots 22 and the number of cooling slots 23 correspond one-to-one with the number of magnetic slots 21. Figure 8 , Figure 9 As shown, the rotor core 2 of this embodiment has 18 magnetic steel slots 21, 18 sets of second wire slots 22, and 18 cooling slots 23, and one magnetic steel slot 21 corresponds to one set of second wire slots 22 and one cooling slot 23.
[0018] Permanent magnets are embedded in the magnetic slots 21 of the rotor core 2, and excitation coils are wound in the second slot 22 of the rotor core 2, forming a hybrid motor in which both permanent magnets and excitation windings are placed on the rotor. By superimposing the excitation and permanent magnets, the motor speed and electromagnetic strength are controlled by the frequency converter signal, achieving controllable torque. Compared with traditional excitation motors, this method is more complex and more efficient.
[0019] The stator assembly includes a stator core 3 and a stator winding. The stator core 3 is formed by stacking multiple silicon steel sheets and is located outside the rotor core 2. A first slot 31 is provided on the side of the stator core 3 closest to the rotor assembly, and the stator winding is wound in the first slot 31.
[0020] The motor housing 4 is fitted onto the outside of the stator assembly, and the inner wall of the motor housing 4 is in contact with the outer wall of the stator core 3. The outer peripheral wall of the motor housing 4 is provided with several axially extending heat dissipation fins 41, and each heat dissipation fin 41 is equipped with several sets of heat dissipation fins 42. This increases the heat dissipation area, further improves heat dissipation efficiency, and thus alleviates motor temperature rise.
[0021] The front cover 5 and the rear cover 6 are respectively fixed to both ends of the motor housing 4, and the front cover 5 and the rear cover 6 are rotatably connected to the rotating shaft 1. A first bearing is provided in the middle of the front cover 5, and the front end of the rotating shaft 1 passes through the first bearing and is rotatably connected to the front cover 5. A second bearing is provided in the middle of the rear cover 6, and the rear end of the rotating shaft 1 is rotatably connected to the rear cover 6 through the second bearing.
[0022] The front cover 5 has several air inlet holes 51 circumferentially arranged on its upper edge, and the rear cover 6 has several air outlet holes 61 circumferentially arranged on its upper edge. An air inlet shroud 7 is provided on the side of the front cover 5 away from the rear cover 6, and several ventilation openings 71 are provided on the side wall of the air inlet shroud 7. A guide plate 8 is provided on the front cover 5 between the air inlet holes 51 and the air inlet shroud 7, and a cooling fan 9 is provided on the side of the guide plate 8 near the ventilation openings 71. The cooling fan includes an annular fan shaft 91. An annular groove is provided on the front cover 5 between the guide plate 8 and the air inlet shroud 7, and several coils 92 are provided in the annular groove. Several grooves 93 are provided at the bottom of the annular fan shaft 91, and permanent magnets are embedded in the grooves 93. The bottom of the annular fan shaft 91 is slidably connected to the coils 92. Several fan blades 94 are provided on the side of the annular fan shaft 91 away from the guide plate 8. The circles formed by all air inlets 51, all air outlets 61, and all cooling slots 23 have the same radius and their centers are all located on the axis of the rotating shaft 1.
[0023] To prevent the permanent magnet from demagnetizing due to the high temperature generated after power-on, cooling is required. This utility model sets up a cooling channel formed by the interconnected ventilation port 71, air inlet hole 51, cooling groove 23, and air outlet hole 61. During motor operation, the coil 92 is energized to form a magnetic field that interacts with the permanent magnet in the groove 93, causing the annular fan shaft 91 to rotate and drive the fan blades 94 to rotate. Under the action of the cooling fan 9, the airflow enters the air inlet cover 7 through the ventilation port 71, then is guided by the guide plate 8, enters the internal cavity of the motor through the air inlet hole, is cooled by the cooling groove 23, and finally blown out through the air outlet hole 61. The air cooling reduces the temperature inside the motor, especially the rotor, and can better dissipate heat.
[0024] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. An air-cooled high-efficiency permanent magnet motor, comprising: Shaft; Rotor assembly; The rotor assembly includes a rotor core, which is sleeved and fixed to the middle of the rotating shaft; Stator assembly; the stator assembly includes a stator core and a stator winding, the stator core is formed by stacking multiple silicon steel sheets, the stator core is disposed outside the rotor core; a first slot is formed on the side of the stator core near the rotor assembly, and the stator winding is wound in the first slot; Motor housing; the motor housing is fitted onto the outside of the stator assembly, and the inner wall of the motor housing is in contact with the outer wall of the stator core; A front cover and a rear cover; the front cover and the rear cover are respectively fixed to both ends of the motor housing, and the front cover and the rear cover are respectively rotatably connected to the rotating shaft; Its features are: The rotor core has several magnetic steel slots, several sets of second wire slots, and several cooling slots sequentially opened from the outside to the inside along the circumferential direction. Each magnetic steel slot is embedded with a permanent magnet, and each set of second wire slots is wound with an excitation coil. The front cover has several air inlet holes along its circumference, and the rear cover has several air outlet holes along its circumference. An air inlet hood is provided on the side of the front cover away from the rear cover, and several ventilation openings are provided on the side wall of the air inlet hood. A guide plate is provided on the front cover between the air inlet holes and the air inlet hood, and a cooling fan is provided on the side of the guide plate near the ventilation openings.
2. The air-cooled high-efficiency permanent magnet motor according to claim 1, characterized in that, The outer peripheral wall of the motor housing is provided with several heat dissipation ribs extending along the axial direction, and several sets of heat dissipation fins are installed on each heat dissipation rib.
3. The air-cooled high-efficiency permanent magnet motor according to claim 1, characterized in that, The outer peripheral sidewall of the rotor core is provided with a magnetic break slot, which is located between two magnetic steel slots; the magnetic steel slot, the second wire slot, the cooling slot, and the magnetic break slot all extend along the axial direction of the rotor core; the number of groups of the second wire slot and the number of cooling slots are the same as the number of magnetic steel slots and correspond one-to-one.
4. The air-cooled high-efficiency permanent magnet motor according to claim 1, characterized in that, All the circles formed by the air inlets, the air outlets, and the cooling grooves have the same radius and their centers are all located on the axis of the rotating shaft.
5. The air-cooled high-efficiency permanent magnet motor according to claim 1, characterized in that, The cooling fan includes an annular fan shaft; an annular groove is provided on the front end cover between the guide plate and the air inlet shroud, and a plurality of coils are provided in the annular groove; a plurality of grooves are provided at the bottom of the annular fan shaft, and permanent magnets are embedded in the grooves; the bottom of the annular fan shaft is slidably connected to the coils; a plurality of fan blades are provided on the side of the annular fan shaft away from the guide plate.