A noise reduction structure for magnetic tiles and a diaphragm pump motor

Abstract

This utility model provides a magnetic tile noise reduction structure, including a magnetic tile body. The cross-section of the magnetic tile body is arc-shaped, having an outer arc-shaped surface and an inner arc-shaped surface. The outer arc-shaped surface and the two sides of the inner arc-shaped surface are connected by side surfaces. The centers of the outer arc-shaped surface and the inner arc-shaped surface are eccentrically positioned, and the distance from the center of the inner arc-shaped surface to the magnetic tile body is greater than the distance from the center of the outer arc-shaped surface to the magnetic tile body. The thickness of the magnetic tile body gradually decreases from the middle to both sides. The two sides of the inner arc-shaped surface are provided with first chamfers to form first inclined surfaces, and the inner arc-shaped surface is connected to the side surfaces through the first inclined surfaces. This utility model's magnetic tile noise reduction structure and diaphragm pump motor effectively reduce motor cogging torque and torque pulsation, making the air gap magnetic flux density sinusoidal, reducing harmonic content and electromagnetic noise, resulting in good performance.

Description

Technical Field

[0001] This utility model relates to the field of motors, and in particular to a magnetic tile noise reduction structure and a diaphragm pump motor. Background Technology

[0002] As the noise requirements for diaphragm pumps used in water purifiers become increasingly stringent, the noise requirements for diaphragm pump motors also increase accordingly. Among various types of motor noise, electromagnetic noise is a significant component. The magnetic circuit design of the motor (such as the magnet structure design) has a substantial impact on electromagnetic noise. Currently, most diaphragm pump motors on the market use a concentric, equal-thickness magnet structure design. This magnet structure design generates significant cogging torque and torque pulsation, resulting in a rectangular wave distribution of the air gap magnetic flux density. This rectangular wave contains a large number of odd harmonics, leading to increased electromagnetic noise and a less than ideal user experience. Summary of the Invention

[0003] The technical problem to be solved by this utility model is to provide a magnetic tile noise reduction structure and diaphragm pump motor that can effectively reduce motor cogging torque and torque pulsation, make the air gap magnetic flux density present as a sinusoidal waveform, effectively reduce harmonic content and reduce electromagnetic noise.

[0004] This utility model provides a magnetic tile noise reduction structure, including a magnetic tile body 2. The cross-section of the magnetic tile body 2 is arc-shaped and has an outer arc-shaped surface 21 and an inner arc-shaped surface 22. The outer arc-shaped surface 21 and the two sides of the inner arc-shaped surface 22 are connected by side surfaces 23. The centers of the outer arc-shaped surface 21 and the inner arc-shaped surface 22 are eccentrically set, and the distance from the center O' of the inner arc-shaped surface 22 to the magnetic tile body 2 is greater than the distance from the center O of the outer arc-shaped surface 21 to the magnetic tile body 2. The thickness of the magnetic tile body 2 gradually decreases from the middle to both sides. The two sides of the inner arc-shaped surface 22 are provided with first chamfers to form first inclined surfaces 24. The inner arc-shaped surface 22 is connected to the side surfaces 23 through the first inclined surfaces 24.

[0005] This application optimizes the design of the magnetic tile structure, achieving the following effects:

[0006] To reduce torque pulsation, the eccentric design makes the magnetic field waveform sinusoidal and reduces harmonics. At the same time, the weak magnetic field at the edge of the magnetic tile reduces torque abrupt changes during rotor rotation, which improves motor control accuracy and reduces operating noise.

[0007] To reduce electromagnetic noise in motors, sinusoidalization of the air gap magnetic field reduces high-order harmonics of radial electromagnetic force waves, thus suppressing electromagnetic vibration at its source.

[0008] By optimizing the air gap magnetic field distribution to approximate a sine wave, the traditional uniform thickness magnetic tiles generate an air gap magnetic field that is close to a trapezoidal wave with high harmonic content, leading to increased motor torque pulsation and iron loss. The proposed solution adopts an eccentric structure and a chamfered design on both sides. The eccentric design makes the magnetic tile thicker in the center and thinner on both sides, resulting in high magnetic flux in the central area and low magnetic flux in the edge area. This flattens the magnetic field distribution from a "trapezoidal" shape to a quasi-sine wave, reducing high-order harmonics and lowering motor electromagnetic noise.

[0009] The cogging torque, caused by the interaction between the rotor slots and the stator permanent magnets, is reduced. The eccentric design weakens the magnetic field strength on both sides of the magnet, minimizing the sudden magnetic force change when the rotor slots pass the edge of the magnet. This reduces the cogging torque amplitude by 20%–40%, resulting in smoother motor start-up and low-speed operation.

[0010] Furthermore, the magnetic tile body 2 has a symmetrical structure with the line connecting the center of the inner arc surface 22 and the center of the outer arc surface 21 as the axis of symmetry, which has a strong assembly fault tolerance and stable magnetic field symmetry, thus balancing the torque.

[0011] Furthermore, the outer arc-shaped surface 21 has a second chamfer on both sides to form a second inclined surface 26. The outer arc-shaped surface 21 is connected to the side surface 23 through the second inclined surface 26, which further suppresses the cogging torque, reduces torque pulsation, and lowers working noise.

[0012] Furthermore, a third chamfer is provided between the two ends of the side surface and the two end faces of the magnetic tile body to form a third inclined surface 25.

[0013] Furthermore, the center O of the outer arc surface 21 is located in the plane where the side surface 23 is located, ensuring the symmetry and orientation accuracy of the magnetic field and improving the operating accuracy of the motor.

[0014] Furthermore, the central angle α of the magnetic tile body 2 is greater than or equal to 70 degrees and less than or equal to 90 degrees.

[0015] Furthermore, the distance between the center O of the outer arc surface 21 and the center O' of the inner arc surface 22 is 0.5-1 times the difference in radius between the outer arc surface 21 and the inner arc surface 22; this standardizes the air gap magnetic field into a sinusoidal shape, reduces the cogging torque, makes the motor start and stop more smoothly, and reduces operating noise.

[0016] Furthermore, the distance between the center O of the outer arc surface 21 and the center O' of the inner arc surface 22 is 3mm.

[0017] Furthermore, the angle β between the first inclined surface 24 and the width of the magnetic tile body 2 is greater than or equal to 10 degrees and less than or equal to 15 degrees; the cogging torque is caused by the sudden change in the magnetic field between the stator teeth and the edge of the magnetic tile. The above angle causes the magnetic field strength at the edge of the magnetic tile to decrease gradually rather than drop sharply, weakening the magnetic force step when the stator teeth pass through the boundary of the magnetic tile, thus reducing the amplitude of the cogging torque; at the same time, the inclined angle makes the magnetic flux at the edge of the magnetic tile transition linearly, reducing the high-order harmonics in the air gap magnetic field, thereby suppressing the sudden change in torque during current commutation.

[0018] Furthermore, the angle γ between the second inclined surface 26 and the width of the magnetic tile body is greater than or equal to 50 degrees and less than or equal to 70 degrees.

[0019] Meanwhile, this utility model also provides a diaphragm pump motor that uses the above-mentioned magnetic tile noise reduction structure.

[0020] This utility model relates to a magnetic tile noise reduction structure and a diaphragm pump motor. The optimized magnetic tile structure reduces torque pulsation, and the eccentric design sinusoidally shapes the magnetic field waveform, reducing harmonics. Simultaneously, the weak magnetic field at the edge of the magnetic tile reduces torque abrupt changes during rotor rotation, improving motor control accuracy and reducing operating noise. It also reduces motor electromagnetic noise; the sinusoidal air gap magnetic field reduces high-order harmonics of radial electromagnetic force waves, suppressing electromagnetic vibration at its source. Furthermore, the optimized air gap magnetic field distribution approximates a sine wave. Traditional uniform-thickness magnetic tiles generate air gap magnetic fields that are close to trapezoidal waves with high harmonic content, leading to increased motor torque pulsation and iron losses. This application employs an eccentric structure and beveled corners on both sides. The eccentric design results in a magnetic tile structure that is thicker in the center and thinner on both sides, with high magnetic flux in the central area and low magnetic flux in the edge area. This flattens the magnetic field distribution from a "trapezoidal" shape to a quasi-sine wave, reducing high-order harmonics and lowering motor electromagnetic noise. This utility model relates to a magnetic tile noise reduction structure and a diaphragm pump motor, which effectively reduces motor cogging torque and torque pulsation, makes the air gap magnetic flux density present as a sinusoidal waveform, reduces harmonic content and electromagnetic noise, and has good performance. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the diaphragm pump motor of this utility model;

[0022] Figure 2 This is a cross-sectional view of the diaphragm pump motor of this utility model;

[0023] Figure 3 This is a schematic diagram of the magnetic tile noise reduction structure of this utility model;

[0024] Figure 4 This is a front view of the magnetic tile noise reduction structure of this utility model;

[0025] Figure 5 for Figure 3 Enlarged view of section A in the middle;

[0026] Figure 6 The noise value spectrum of the existing magnetic tile simulation test;

[0027] Figure 7 The noise value spectrum of the magnetic tile noise reduction structure of this utility model is obtained from the simulation test.

[0028] Figure 8 The noise frequency spectrum of the existing magnetic tile simulation test;

[0029] Figure 9 The noise frequency spectrum is obtained from the simulation test of the magnetic tile noise reduction structure of this utility model. Detailed Implementation

[0030] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0031] See Figures 3-5 This utility model provides a magnetic tile noise reduction structure, including a magnetic tile body 2. The cross-section of the magnetic tile body 2 is arc-shaped, having an outer arc-shaped surface 21 and an inner arc-shaped surface 22. The outer arc-shaped surface 21 and the inner arc-shaped surface 22 are connected on both sides by side surfaces 23, thereby forming a fan-shaped ring structure. In this application, the centers of the outer arc-shaped surface 21 and the inner arc-shaped surface 22 are eccentrically set, i.e., they are not on the same axis. The distance from the center O' of the inner arc-shaped surface 22 to the magnetic tile body 2 is greater than the distance from the center O of the outer arc-shaped surface 21 to the magnetic tile body 2. This makes the thickness of the magnetic tile body 2 gradually decrease from the middle to both sides. The magnetic flux is high in the central area and low in the edge area, which flattens the magnetic field distribution from a "trapezoidal" shape to a quasi-sine wave, reducing higher harmonics. A first chamfer is provided on both sides of the inner arc-shaped surface 22 to form a first inclined surface 24. The inner arc-shaped surface 22 is connected to the side surfaces 23 through the first inclined surface 24.

[0032] The angle β between the first inclined plane 24 and the width of the magnetic tile body 2 is greater than or equal to 10 degrees and less than or equal to 15 degrees. The cogging torque is caused by the interaction between the rotor cogging and the stator permanent magnet. The above angle makes the magnetic field strength at the edge of the magnetic tile decrease gradually rather than drop sharply, weakening the magnetic force step when the rotor cogging passes the boundary of the magnetic tile, thus reducing the amplitude of the cogging torque. At the same time, the angle makes the magnetic flux at the edge of the magnetic tile transition linearly, reducing the high-order harmonics in the air gap magnetic field, thereby reducing the electromagnetic noise of the motor.

[0033] This application optimizes the design of the magnetic tile structure, achieving the following effects:

[0034] To reduce torque pulsation, the eccentric design makes the magnetic field waveform sinusoidal and reduces harmonics. At the same time, the weak magnetic field at the edge of the magnetic tile reduces torque abrupt changes during rotor rotation, which improves motor control accuracy and reduces operating noise.

[0035] To reduce electromagnetic noise in motors, sinusoidalization of the air gap magnetic field reduces high-order harmonics of radial electromagnetic force waves, thus suppressing electromagnetic vibration at its source.

[0036] By optimizing the air gap magnetic field distribution to approximate a sine wave, the traditional uniform thickness magnetic tiles generate an air gap magnetic field that is close to a trapezoidal wave with high harmonic content, leading to increased motor torque pulsation. The proposed solution adopts an eccentric structure and a chamfered design on both sides. The eccentric design makes the magnetic tile thicker in the center and thinner on both sides, resulting in high magnetic flux in the central area and low magnetic flux in the edge area. This flattens the magnetic field distribution from a "trapezoidal" shape to a quasi-sine wave, reducing high-order harmonics and lowering the electromagnetic noise of the motor.

[0037] The cogging torque, caused by the interaction between the rotor cogging teeth and the stator permanent magnets, is reduced by the eccentric and chamfered design of the magnet tiles, which weakens the magnetic field strength on both sides of the magnet tiles. This reduces the cogging torque amplitude by 20% to 40%, resulting in smoother motor start-up and low-speed operation.

[0038] The magnetic tile body 2 in this application has a symmetrical structure, with the line connecting the center of the inner arc surface 22 and the center of the outer arc surface 21 as the axis of symmetry. It has a strong assembly fault tolerance, stable magnetic field symmetry, and balanced torque.

[0039] In this embodiment, the distance between the center O of the outer arc surface 21 and the center O' of the inner arc surface 22 is 0.5-1 times the difference in radius between the outer arc surface 21 and the inner arc surface 22; this makes the air gap magnetic field standard sinusoidal, reduces the cogging torque, makes the motor start and stop more smoothly, and reduces operating noise; preferably, it is 0.7-0.8 times, achieving better operating performance.

[0040] In this embodiment, the radius R of the outer arc surface 21 is 30-31 mm, the radius r of the inner arc surface 22 is 23-24 mm, and the distance between the center O of the outer arc surface 21 and the center O' of the inner arc surface 22 is 3 mm.

[0041] To further reduce operating noise, in this application, the outer arc surface 21 is provided with second chamfers on both sides to form a second inclined surface 26. The outer arc surface 21 is connected to the side surface 23 through the second inclined surface 26, which further reduces the cogging torque, reduces torque pulsation, and reduces operating noise. In this embodiment, the angle γ between the second inclined surface 26 and the width of the magnetic tile body is greater than or equal to 50 degrees and less than or equal to 70 degrees. The width of the magnetic tile is a chord perpendicular to the axis of symmetry of the magnetic tile body, which is the direction of the line connecting the two sides of the magnetic tile body 2.

[0042] In addition, this utility model also provides a diaphragm pump motor, see reference. Figures 1-2 It includes a motor housing 1, with a mounting cavity inside the motor housing 1. Magnetic tile bodies 2 are arranged in multiple units and evenly distributed circumferentially within the mounting cavity. A rotor 3 is located at the center of the mounting cavity. After optimization design, the magnetic tiles spatially modulate the air gap magnetic field, making the magnetic field sinusoidal, thereby reducing harmonic losses; weakening the edge magnetic field, thereby suppressing cogging torque / torque pulsation; and thus improving the motor's working efficiency, smoothness, and quietness.

[0043] Meanwhile, noise simulation tests were conducted on traditional magnetic tile structures and the magnetic tile of this application, and the results were compared.

[0044] See Figure 6 and Figure 7 As can be seen from the figure, the average sound power level of the existing magnetic tile structure is 53.49 dB, while the average sound power level of the magnetic tile with the optimized structure is 49.84 dB, a reduction of 3.65 dB. This reduction from 53.49 dB to 49.84 dB crosses the watershed between "acceptable noise" and "excellent quietness" (50 dB is the psychoacoustic threshold), significantly improving the quietness of motor operation.

[0045] See Figure 8 and Figure 9 The existing magnetic tile structure has a noise frequency of 10,000 Hz, while the optimized magnetic tile has a noise frequency of 5,000-6,000 Hz, which is a significant reduction in frequency. The human ear is most sensitive to 4-8 kHz, but its tolerance to 5-6 kHz is better than that to 10 kHz. The optimized thickness reduces the harshness of high frequencies, improves the subjective sense of quietness, enhances the ear's perceived comfort, and provides a better user experience.

[0046] This utility model relates to a magnetic tile noise reduction structure and a diaphragm pump motor. The optimized magnetic tile structure reduces torque pulsation, and the eccentric design sinusoidally shapes the magnetic field waveform, reducing harmonics. Simultaneously, the weak magnetic field at the edge of the magnetic tile reduces torque abrupt changes during rotation, improving motor control accuracy and reducing operating noise. It also reduces motor electromagnetic noise; the sinusoidal air gap magnetic field reduces high-order harmonics of radial electromagnetic force waves, suppressing electromagnetic vibration at its source. Furthermore, the optimized air gap magnetic field distribution approximates a sine wave. Traditional uniform-thickness magnetic tiles generate air gap magnetic fields that are close to trapezoidal waves with high harmonic content, leading to increased motor torque pulsation. This application employs an eccentric structure and beveled corners on both sides. The eccentric design results in a magnetic tile that is thicker in the center and thinner on both sides, with high magnetic flux in the central area and low magnetic flux in the edge area. This flattens the magnetic field distribution from a "trapezoidal" shape to a quasi-sine wave, reducing high-order harmonics and lowering motor electromagnetic noise. This utility model relates to a magnetic tile noise reduction structure and a diaphragm pump motor, which effectively reduces motor cogging torque and torque pulsation, makes the air gap magnetic flux density present as a sinusoidal waveform, reduces harmonic content and electromagnetic noise, and has good performance.

[0047] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A magnetic tile noise reduction structure, characterized in that: The device includes a magnetic tile body with an arc-shaped cross-section having an outer arc surface and an inner arc surface. The outer arc surface and the two sides of the inner arc surface are connected by side surfaces. The centers of the outer arc surface and the inner arc surface are eccentrically positioned, and the distance from the center of the inner arc surface to the magnetic tile body is greater than the distance from the center of the outer arc surface to the magnetic tile body. The thickness of the magnetic tile body gradually decreases from the middle to both sides. The two sides of the inner arc surface are provided with first chamfers to form first inclined surfaces, and the inner arc surface is connected to the side surfaces through the first inclined surfaces.

2. The magnetic tile noise reduction structure of claim 1, wherein: The outer arc-shaped surface has a second chamfer on both sides to form a second inclined surface, and the outer arc-shaped surface is connected to the side surface through the second inclined surface.

3. The magnetic tile noise reduction structure as described in claim 1, characterized in that: A third chamfer is provided between the two ends of the side surface and the two end faces of the magnetic tile body, forming a third inclined surface.

4. The magnetic tile noise reduction structure of claim 1, wherein: The center of the outer arc surface lies within the plane containing the side surface.

5. The magnetic tile noise reduction structure of claim 1, wherein: The central angle α of the magnetic tile body is greater than or equal to 70 degrees and less than or equal to 90 degrees.

6. The magnetic tile noise reduction structure of claim 1, wherein: The distance between the center of the outer arc surface and the center of the inner arc surface is 0.5 to 1 times the difference in radii between the outer arc surface and the inner arc surface.

7. The magnetic tile noise reduction structure of claim 1, wherein: The distance between the center of the outer arc surface and the center of the inner arc surface is 3mm.

8. The magnetic tile noise reduction structure of claim 1, wherein: The angle β between the first inclined plane and the width of the magnetic tile body is greater than or equal to 10 degrees and less than or equal to 15 degrees.

9. The magnetic tile noise reduction structure of claim 2, wherein: The angle γ between the second inclined plane and the width of the magnetic tile body is greater than or equal to 50 degrees and less than or equal to 70 degrees.

10. A diaphragm pump motor characterized by: The magnetic tile noise reduction structure as described in any one of claims 1-9 is used.

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