A stator structure and processing method for stator tooth shearing

Abstract

This invention relates to the field of motor stator core technology, specifically to a stator structure and processing method for stator tooth shearing. The stator structure includes a stator core formed by stacking multiple stator laminations. The inner side of each stator lamination is serrated, including stator teeth and slots. A toothed shoe is provided on each stator tooth, located at the end of the tooth, with its circumferential width greater than the circumferential width of the stator tooth. Each stator tooth includes multiple first teeth and at least one second tooth. Each first tooth includes a first toothed shoe; each second tooth includes a second toothed shoe, located at the end of the second tooth, with its radial width less than the radial width of the first toothed shoe. This invention can solve the problem of excessive electromagnetic force in motors, reducing the electromagnetic force at the breathing mode and decreasing noise across the entire motor speed range.

Description

Technical Field

[0001] This invention relates to the field of motor stator core technology, specifically to a stator structure and processing method for stator tooth shearing. Background Technology

[0002] Permanent magnet synchronous motors (PMSMs) boast advantages such as high efficiency, high reliability, and high power density, making them widely used in various fields including industrial manufacturing, home appliances, shipbuilding, and new energy vehicles. With the continuous development of motor technology, products prioritizing user comfort, such as air conditioner indoor units and drive motors for new energy vehicles, are placing increasingly stringent requirements on electromagnetic noise levels, necessitating the further development of low-noise PMSMs.

[0003] Current permanent magnet synchronous motors primarily address electromagnetic noise through stator tooth shaving or slotting. Without any optimization, connecting the stator teeth creates a complete circle. Stator tooth shaving involves flattening the arc on both sides of each tooth, or making the radius of the arc on the sides larger than the radius of the arc at the center of the tooth. Stator tooth slotting involves creating slots in each stator tooth, breaking up the arc. Both shaving and slotting enlarge the air gap, increasing the magnetic reluctance of the motor's magnetic circuit and reducing its output capacity. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a stator structure and processing method for stator tooth shearing, so as to solve the problem that the optimization of the stator teeth in the prior art will enlarge the air gap of the motor, thereby increasing the magnetic reluctance of the motor magnetic circuit and affecting the output capacity of the motor.

[0005] The technical solution of the present invention is: a stator structure for stator tooth shearing, comprising:

[0006] A stator core is formed by rotating and stacking stator laminations. The inner side of the stator laminations is serrated, including stator teeth and slots. The stator teeth are provided with toothed shoes, which are located at the ends of the stator teeth and have a circumferential width greater than the circumferential width of the stator teeth.

[0007] The stator teeth include a plurality of first teeth and at least one second tooth;

[0008] The first tooth includes a first toothed shoe, which is located at the end of the first tooth and has a circumferential width greater than the circumferential width of the first tooth.

[0009] The second tooth includes a second toothed shoe located at the end of the second tooth, the second toothed shoe having a circumferential width greater than the circumferential width of the second tooth and a radial width less than the radial width of the first toothed shoe.

[0010] According to the stator structure for stator tooth shearing provided in this application, each of the second teeth is evenly distributed in the circumferential direction.

[0011] According to the stator structure for stator tooth shearing provided in this application, in each of the smallest units, the product of the number of the second teeth and the number of motor phases is equal to the total number of stator teeth.

[0012] According to the stator structure for stator tooth shearing provided in this application, the width of the second tooth shoe in the radial direction is between 0.3 and 0.7 times the width of the first tooth shoe in the radial direction.

[0013] According to the stator structure for stator tooth shearing provided in this application, the circle containing the arc at the end of the first tooth shoe and the circle containing the arc at the end of the second tooth shoe are concentric circles.

[0014] According to the present application, a stator structure with stator tooth shearing is provided, the stator structure comprising multiple stator core segments stacked together.

[0015] According to the stator structure with stator tooth shearing provided in this application, the stator core is rotated and stacked around the axial direction at a set angle during stacking, so that the second tooth of the stator core coincides with the first tooth of the stator core adjacent to it in the axial direction.

[0016] Based on the same inventive concept, this application also provides a method for processing a stator core, the method being applicable to any of the stator tooth shearing stator structures described above, comprising:

[0017] Determine the number of the second teeth: at least one second tooth must be machined; the number of the second teeth is negatively correlated with the number of phases of the motor;

[0018] The position of the second tooth is determined as follows: the second tooth is evenly distributed circumferentially;

[0019] Processing the stator teeth: cutting the tooth shoe of the stator teeth, the processed stator teeth are the second teeth, and the unprocessed stator teeth are the first teeth; the radial width of the second tooth shoe of the second teeth is smaller than the radial width of the first tooth shoe of the first teeth.

[0020] Stacked stator laminations: Stator laminations are stacked to form multiple stator core segments;

[0021] Rotary stacking of stator core: The stator core is rotated and stacked around the axial direction at a set angle, so that the stator teeth of the stacked stator core coincide with the stator teeth of the stator core adjacent to it in the axial direction.

[0022] According to the processing method of stator structure for stator tooth shearing provided in this application, the product of the number of the second teeth and the number of motor phases is equal to the total number of stator teeth.

[0023] According to the processing method of stator structure for stator tooth shearing provided in this application, when processing the stator tooth, the shearing is performed parallel to the curvature of the stator tooth shoe, so that the curvature of the second tooth shoe after processing is the same as the curvature of the first tooth shoe before processing.

[0024] According to the processing method of stator structure for stator tooth shearing provided in this application, when processing the tooth shoe of the stator tooth, the radial width of the second tooth shoe after processing is between 0.3 and 0.7 times the radial width of the first tooth shoe of the unprocessed first tooth.

[0025] According to the processing method of stator structure by stator tooth shearing provided in this application, when the stator core is rotated and stacked, the second tooth of the stator core is made to coincide with the first tooth of the stator core adjacent to it in the axial direction.

[0026] The advantages of this application are:

[0027] 1. This application can effectively solve the problem of excessive electromagnetic force in motors, reduce the electromagnetic force at the breathing mode, and reduce the noise of motors across the entire speed range;

[0028] 2. The second teeth of this application are evenly distributed in the circumferential direction, which helps to reduce the noise of the motor in the circumferential direction in a balanced way and avoid excessive local noise affecting the overall noise performance of the motor.

[0029] 3. The number of the second teeth in this application is negatively correlated with the number of phases of the motor. When the total number of stator teeth is constant, the fewer the number of motor phases, the more the number of the second teeth in this application, and the more obvious the noise reduction effect. The more the number of motor phases, the fewer the number of the second teeth in this application, and the weaker the noise reduction effect. This avoids the diminishing marginal effect and can also reduce the number of stator teeth to be processed, saving manufacturing time and costs.

[0030] 4. The circle containing the arc at the end of the first toothed shoe and the circle containing the arc at the end of the second toothed shoe are concentric circles, which can weaken the influence of the effective air gap of the motor, avoid increasing the magnetic resistance of the motor magnetic circuit, and ensure the output capacity of the motor.

[0031] 5. In this application, the stator cores are rotated and stacked around the axial direction at a set angle, so that the second tooth of the adjacent stator cores in the axial direction coincides with the first tooth. This can prevent the effective air gap of the motor from expanding further, and effectively reduce the noise of the motor while ensuring the output capacity of the motor.

[0032] 6. The radial width of the second toothed shoe in this application is controlled between 0.3 and 0.7 times the radial width of the first toothed shoe. If the width of the second toothed shoe is too large, the effective air gap of the motor will be insufficient, resulting in an insignificant noise reduction effect of the motor. If the width of the second toothed shoe is too small, the effective air gap of the motor will be too large, increasing the magnetic resistance of the motor's magnetic circuit and reducing the motor's output capacity. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the stator lamination for this application;

[0034] Figure 2 For this application Figure 1 A magnified schematic diagram of part A;

[0035] Figure 3 This is a schematic diagram of the stator core of this application;

[0036] Wherein: 1-first tooth; 11-first toothed shoe; 2-second tooth; 21-second toothed shoe; 100-first iron core; 200-second iron core; 300-third iron core; Detailed Implementation

[0037] Embodiments of the present invention are described in detail below, 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 intended to explain the present invention, and should not be construed as limiting the present invention.

[0038] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "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 invention 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 invention.

[0039] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0040] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0041] This application relates to a stator structure with stator tooth shearing, which aims to solve the problem of excessive noise during operation of permanent magnet synchronous motor. This application optimizes the teeth of the stator structure to reduce motor operating noise while controlling the effective air gap of the motor, avoiding the increase of magnetic resistance of the motor magnetic circuit due to excessive air gap, which would affect the output capacity of the motor.

[0042] Specifically, such as Figure 1 , 2 As shown, the stator structure of this application includes a stator core, which is formed by stacking multiple stator laminations. The inner side of the stator laminations is serrated, including stator teeth and slots. The stator teeth are provided with toothed shoes, which are located at the ends of the stator teeth and have a circumferential width greater than the circumferential width of the stator teeth.

[0043] The stator teeth include a plurality of first teeth 1 and at least one second tooth 2;

[0044] The first tooth portion 1 includes a first toothed shoe 11, which is located at the end of the first tooth portion 1 and has a circumferential width greater than the circumferential width of the first tooth portion 1.

[0045] The second tooth portion 2 includes a second toothed shoe 21, which is located at the end of the second tooth portion 2. Its circumferential width is greater than the circumferential width of the second tooth portion 2, and its radial width is less than the radial width of the first toothed shoe 11.

[0046] The stator teeth are serrated portions located inside the stator laminations. The ends of the stator teeth extend outwards in the circumferential direction to form toothed shoes. In this application, the toothed shoes of a portion of the stator teeth are processed. The processed stator teeth are the second teeth 2, and the unprocessed stator teeth are the first teeth 1. The radial width of the second toothed shoe 21 of the second teeth 2 is smaller than the radial width of the first toothed shoe 11 of the first teeth 1.

[0047] The effective air gap of an electric motor refers to the gap between the rotor and the stator. The smaller the effective air gap, the greater the noise during operation, the lower the magnetic reluctance of the motor's magnetic circuit, and the greater the output power. Conversely, the larger the effective air gap, the lower the noise during operation, the greater the magnetic reluctance of the motor's magnetic circuit, and the lower the output power.

[0048] Specifically, the radial width of the second toothed shoe 21 is controlled between 0.3 and 0.7 times the radial width of the first toothed shoe 11, ensuring an effective air gap of appropriate size within the motor. This reduces noise generated during motor operation while maintaining the motor's output capacity. If the width of the second toothed shoe 21 is greater than 0.7 times the width of the first toothed shoe 11, the effective air gap within the motor is too small, resulting in insignificant noise reduction. Conversely, if the width of the second toothed shoe 21 is less than 0.3 times the width of the first toothed shoe 11, the effective air gap within the motor is too large, increasing the magnetic reluctance of the motor's magnetic circuit and reducing the motor's output capacity.

[0049] In some embodiments, the stator teeth described above have been optimized, such as... Figure 1 , 2 As shown, in this embodiment, the second tooth 2 in the stator tooth section is evenly distributed in the circumferential direction.

[0050] Specifically, in this embodiment, taking a three-phase motor as an example, a second tooth 2 is provided every two first teeth 1, so that the second teeth 2 are evenly distributed in the circumferential direction of the stator lamination, thereby uniformly expanding the effective air gap of the motor in the circumferential direction and ensuring that the noise reduction effect of the motor is uniform in all parts of the circumferential direction.

[0051] Furthermore, the product of the number of second teeth 2 and the number of motor phases is equal to the total number of stator teeth.

[0052] Specifically, with a fixed total number of stator teeth, the more phases the motor has, the smoother the motor operates, the better the noise performance, the lower the noise reduction requirement, and the fewer the number of second teeth 2 required; the fewer phases the motor has, the greater the noise performance during operation, the higher the noise reduction requirement, and the more the number of second teeth 2 required.

[0053] The number of second teeth 2 is negatively correlated with the number of phases of the motor. When the total number of stator teeth is constant, the fewer the number of motor phases, the more second teeth 2 there are in this application, and the more obvious the noise reduction effect is. The more the number of motor phases, the fewer second teeth 2 there are in this application, and the weaker the noise reduction effect is. This avoids the marginal diminishing effect and can also reduce the number of stator teeth to be processed, saving manufacturing time and costs.

[0054] In this embodiment, a 54-slot three-phase motor is used as an example. The number of second teeth 2 = number of motor slots / number of motor phases = 54 / 3 = 18. According to simulation analysis, when the number of second teeth 2 of the 54-slot three-phase motor is 18, the 12th order electromagnetic force at the breathing mode is reduced from 2700Pa to 2030Pa, and the noise performance across the entire speed range is optimized by a maximum of 8dB.

[0055] Meanwhile, compared with the prior art of arc cutting treatment on stator teeth, the noise optimization performance of this application is improved by 20%-30%; compared with the prior art of slotting treatment on stator teeth, the motor output capacity of this application is improved by 15%-25%.

[0056] In some embodiments, the arc of the stator teeth is optimized, such as... Figure 1 , 2 As shown, in this embodiment, the circle containing the arc at the end of the first toothed shoe 11 and the circle containing the arc at the end of the second toothed shoe 21 are concentric circles.

[0057] In fact, by controlling the circle containing the arc at the end of the first toothed shoe 11 and the circle containing the arc at the end of the second toothed shoe 21 to be concentric circles, the effective air gap of the motor can be kept within a small range. This reduces the noise of the motor during operation while ensuring the output capacity of the motor. It also avoids the situation where the effective air gap of the motor is too large due to the inconsistency between the arc at the end of the first toothed shoe 11 and the arc at the end of the second toothed shoe 21, which would increase the magnetic reluctance of the motor's magnetic circuit and reduce the output capacity.

[0058] In some embodiments, the stator core described above has been optimized, such as... Figure 3 As shown, in this embodiment, the stator structure includes multiple stator cores stacked together. When the stator cores are stacked, they are rotated and stacked around the axial direction at a set angle, so that the second tooth 2 of the stator core coincides with the first tooth 1 of the stator core adjacent to it in the axial direction.

[0059] When the second tooth 2 of two axially adjacent stator cores coincides with the first tooth 1, the second tooth 2 of the axially adjacent stator cores and the first tooth 1 are arranged alternately. This reduces the effect of the motor output capacity being reduced due to the air gap caused by the second tooth shoe 21 being smaller in the radial direction than the first tooth shoe 11. This reduces the noise generated when the motor is working while ensuring the output capacity of the motor.

[0060] Taking a 54-slot three-phase motor as an example, this embodiment includes three stator cores stacked together. The stator core is formed by stacking multiple stator laminations. Each stator lamination includes eighteen second teeth 2 and thirty-six first teeth 1. The eighteen second teeth 2 are evenly distributed in the thirty-six first teeth 1. When stacking the three stator cores, the first core 100 is left stationary; the second core 200 is rotated α (α = (360 / 54) * N°, where N is a non-zero natural number and α < 360°) with respect to the first core 100, so that the second tooth 2 of the second core 200 coincides with the first tooth 1 of the first core 100; then the third core 300 is rotated β (β = (360 / 54) * M°, where M is any non-zero natural number and β < 360°) with respect to the second core 200, so that the second tooth 2 of the third core 300 coincides with the first tooth 1 of the second core 200.

[0061] The processing method of the stator core in this application (taking a 54-slot three-phase motor as an example):

[0062] Determine the number of the second tooth section 2: The total number of stator teeth is equal to the number of motor slots, which is fifty-four. The number of motor phases is three. Therefore, the number of the second tooth section 2 is eighteen, and the number of the first tooth section 1 is thirty-six.

[0063] Determine the position of the second tooth 2: Distribute the eighteen second teeth 2 evenly in the circumferential direction among the thirty-six first teeth 1, that is, set one second tooth 2 every two first teeth 1;

[0064] Machining stator teeth: Cut a tooth shoe for every two stator teeth. The finished stator teeth are called the second tooth 2, and the unmachined stator teeth are called the first tooth 1. The radial width of the second tooth shoe 21 of the second tooth 2 is less than the radial width of the first tooth shoe 11 of the first tooth 1.

[0065] Stacked stator laminations: Stator laminations are stacked to form multiple stator core segments; such as... Figure 3 As shown, this embodiment includes three stator core segments, each stator core segment including multiple stator laminations stacked together; in some embodiments, when stacking the stator laminations, the stator laminations can be rotated and stacked at a set angle, so that the second tooth 2 of two adjacent stator laminations along the axial direction coincides with the first tooth 1.

[0066] Rotary stacking of stator cores: The stator cores are rotated and stacked around their axial direction at a predetermined angle, such that the second tooth 2 of the stator core coincides with the first tooth 1 of its axially adjacent stator core; for example... Figure 3As shown, this embodiment includes three stator cores. When stacking the stator cores, the first core 100 is placed at rest. The second core 200 is rotated by α (α = (360 / 54) * N°, where N is a non-zero natural number and α < 360°) with the first core 100 as the reference, so that the second tooth 2 of the second core 200 coincides with the first tooth 1 of the first core 100. Then, the third core 300 is rotated by β (β = (360 / 54) * M°, where M is any non-zero natural number and β < 360°) with the second core 200 as the reference, so that the second tooth 2 of the third core 300 coincides with the first tooth 1 of the second core 200.

[0067] In some embodiments, the above-described steps for machining stator teeth have been optimized, such as... Figure 1 , 2 As shown, when machining the stator teeth, the cutting is performed parallel to the arc of the stator teeth's tooth shoe, so that the arc of the finished second tooth 2 tooth shoe is the same as the arc of the unmachined first tooth 1 tooth shoe, ensuring that the circle containing the end arc of the first tooth 1 tooth shoe 11 of the first tooth 1 and the circle containing the end arc of the second tooth 2 tooth shoe 21 of the second tooth 2 are concentric circles.

[0068] Furthermore, such as Figure 1 , 2 As shown, when machining the stator teeth, the width of the second tooth 21 after machining is controlled to be between 0.3 and 0.7 times the width of the unmachined first tooth 11. If the width of the second tooth 21 is greater than 0.7 times the width of the first tooth 11, the effective air gap in the motor is too small, and the noise reduction effect is not obvious. If the width of the second tooth 21 is less than 0.3 times the width of the first tooth 11, the effective air gap in the motor is too large, the magnetic resistance of the motor magnetic circuit increases, and the output capacity of the motor decreases.

[0069] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A stator structure for stator tooth shearing, characterized in that, The stator structure includes a stator core consisting of multiple segments stacked together. The stator core is formed by stacking multiple stator laminations. The inner side of each stator lamination is serrated, including stator teeth and slots. A toothed shoe is provided on the stator teeth, which is located at the end of the stator teeth and has a circumferential width greater than the circumferential width of the stator teeth. The stator teeth include a plurality of first teeth (1) and at least one second tooth (2). The first tooth (1) includes a first toothed shoe (11), which is located at the end of the first tooth (1) and has a circumferential width greater than the circumferential width of the first tooth (1). The second tooth (2) includes a second toothed shoe (21), which is located at the end of the second tooth (2). Its circumferential width is greater than the circumferential width of the second tooth (2), and its radial width is 0.3 to 0.7 times the radial width of the first toothed shoe (11). The circle containing the arc of its end is concentric with the circle containing the arc of the end of the first toothed shoe (11). The stator structure includes multiple stator cores stacked together. When stacking, the stator cores are rotated and stacked around the axial direction at a set angle, so that the second tooth (2) of the stator core coincides with the first tooth (1) of the stator core adjacent to it in the axial direction.

2. The stator structure for stator tooth shearing as described in claim 1, characterized in that, The second tooth (2) is evenly distributed in the circumferential direction.

3. The stator structure for stator tooth shearing as described in claim 2, characterized in that, The product of the number of the second tooth (2) and the number of motor phases is equal to the total number of stator teeth.

4. A method for processing a stator structure by shearing stator teeth, characterized in that, The method is used for a stator structure for stator tooth shearing as described in any one of claims 1 to 3, comprising: Determine the number of the second tooth (2): at least one second tooth (2) must be machined; the number of the second tooth (2) is negatively correlated with the number of phases of the motor; Determine the position of the second tooth (2): The second tooth (2) is evenly distributed circumferentially; Processing the stator teeth: shearing the tooth shoe of the stator teeth, the processed stator teeth are the second teeth (2), and the unprocessed stator teeth are the first teeth (1); the width of the second tooth (2) and the second tooth shoe (21) in the radial direction is smaller than the width of the first tooth (1) and the first tooth shoe (11) in the radial direction. Stacked stator laminations: Stator laminations are stacked to form multiple stator core segments; Rotary stacking of stator core: The stator core is rotated and stacked around the axial direction at a set angle, so that the second tooth (2) of the stacked stator core coincides with the first tooth (1) of the stator core adjacent to it in the axial direction.

5. The method for processing a stator structure by shearing stator teeth as described in claim 4, characterized in that, The product of the number of the second tooth (2) and the number of motor phases is equal to the total number of stator teeth.

6. The method for processing a stator structure by shearing stator teeth as described in claim 4, characterized in that, When processing the stator teeth, shearing is performed parallel to the curvature of the stator teeth's tooth shoe, so that the curvature of the second tooth (2) and the second tooth shoe (21) after processing is the same as the curvature of the first tooth (1) and the first tooth shoe (11) before processing.

7. The method for processing a stator structure by shearing stator teeth as described in claim 6, characterized in that, When machining the stator teeth, the width of the second tooth (2) and the second tooth (21) after machining is between 0.3 and 0.7 times the width of the first tooth (1) and the first tooth (11) before machining.

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