TW202131602A - Permanent magnet motor capable of reducing torque ripple and increasing output torque to improve performance and stability of permanent magnet motor - Google Patents

Abstract

A permanent magnet motor comprises a stator and a rotor, wherein the rotor is mounted in the stator, and the rotor can rotate relative to the stator. The rotor includes a main body, and the outer side of the main body is formed with an outer peripheral surface. There is an air gap between the outer peripheral surface and the stator. The main body is inserted with a plurality of first magnets, a plurality of second magnets, and a plurality of third magnets, which are arranged radially on the main body. The second magnet and the third magnet are symmetrically disposed on both sides of the first magnet, and the first magnet is located between the outer peripheral surface of the main body, the second magnet and the third magnet.

Description

Permanent magnet motor

The present invention relates to a motor, especially a permanent magnet motor.

The interior permanent magnet motor (Interior Permanent Magnet Motor) has many advantages such as high power density and high efficiency, because the saliency of the rotor makes it not only the Electromagnetic Torque of the motor itself, but also Additional reluctance torque (Reluctance Torque) is obtained. Therefore, the application range in the high-speed region has a better and wider working range than the general surface permanent magnet motor, and it has been widely used in various fields at present. One of the main factors affecting the output characteristics of the built-in permanent magnet motor is the design of the built-in permanent magnet motor rotor.

The ratio of the rotor direct axis inductance to the quadrature axis inductance is the saliency ratio. When the saliency ratio is greater, a greater reluctance torque can be obtained. When the size of the mechanism in the built-in permanent magnet motor is poorly designed, it will cause the output torque to fluctuate, and a large Torque Ripple will result in severe vibration and noise. Therefore, how to improve the structural design of the built-in permanent magnet motor, while increasing the output torque at the same time, reduce the torque fluctuation, effectively suppress vibration and noise, and smooth and stable output torque, which requires in-depth research. Subject.

In view of this, the inventors have actively researched, combined with years of experience in related product research and development, and after continuous experiments and improvements, finally developed the present invention.

In view of the aforementioned problems of the prior art, the present invention provides a permanent magnet motor, including a stator and a rotor, the rotor is installed in the stator, and the rotor can rotate relative to the stator, wherein the rotor It includes a body, an outer peripheral surface is formed on the outside of the body, and an air gap is formed between the outer peripheral surface and the stator; the body is embedded with a plurality of first magnets, a plurality of second magnets, and a plurality of third magnets. Are arranged on the main body in a radial arrangement, the second magnet and the third magnet are symmetrically placed on both sides of the first magnet, and the first magnet is located on the outer peripheral surface of the main body and the second magnet, the third magnet Between magnets.

In the present invention, the air gap is not a fixed size, it has a maximum air gap and a minimum air gap, and the maximum air gap is 2-6 times the minimum air gap.

In the present invention, there is an included angle between the second magnet and the third magnet, and the included angle is 100 to 120 degrees.

In the present invention, the first magnet has a first thickness in the radial direction of the rotor, the second magnet has a second thickness in the radial direction of the rotor, and the third magnet has a thickness in the radial direction of the rotor. It has a third thickness, and both the second thickness and the third thickness are greater than or equal to the first thickness.

In the present invention, the first magnet has a first width in a direction perpendicular to the first thickness, the second magnet has a second width in a direction perpendicular to the second thickness, and the third magnet has a width in a direction perpendicular to the third thickness. The vertical direction of has a third width, and the second width and the third width are both greater than or equal to the first width.

In the present invention, there is a first distance between the outer peripheral surface of the body and the first magnet, and there is a second distance between the first magnet and the second magnet and the third magnet. There is a third distance between the two magnets and the third magnet, and the third distance is smaller than the first thickness.

In order to make the purpose, features and advantages of the present invention easier to understand by those with ordinary knowledge in the field, a preferred embodiment is given below in conjunction with the accompanying drawings and described in detail as follows.

10: Stator

20: Rotor

21: body

211: Outer peripheral surface

30: The first magnet

31: The second magnet

32: The third magnet

gap: air gap

Theta: included angle

T1: first thickness

T2: second thickness

T3: third thickness

W1: first width

W2: second width

W3: third width

D1: First pitch

D2: second spacing

D3: third spacing

Fig. 1 is a schematic diagram of the structure of the permanent magnet motor of the present invention.

Figure 2 is an enlarged schematic diagram of a partial structure of the permanent magnet motor of the present invention.

FIG. 3 is a schematic diagram of torque ripple of the permanent magnet motor of the present invention when the first pitch is 3 to 8 times the air gap, and the second pitch and the first thickness are at different ratios.

4 is a schematic diagram of output torque at different ratios between the second distance and the first thickness when the first distance of the permanent magnet motor of the present invention is 3 to 8 times the air gap.

Please refer to FIGS. 1 to 2. FIG. 1 is a schematic diagram of the structure of a permanent magnet motor of the present invention, and FIG. 2 is an enlarged schematic view of a partial structure of the permanent magnet motor of the present invention. The present invention relates to a permanent magnet motor, including a stator 10 and a rotor 20, the rotor 20 is installed in the stator 10, and the rotor 20 can rotate relative to the stator 10, wherein the rotor 20 includes a body 21. An outer peripheral surface 211 is formed on the outer side of the main body 21, and an air gap is formed between the outer peripheral surface 211 and the stator 10.

The main body 21 is embedded with a plurality of first magnets 30, a plurality of second magnets 31, and a plurality of third magnets 32, which are arranged radially on the main body 21, the second magnet 31 and the third magnet 32 are placed symmetrically on both sides of the first magnet 30, and the first magnet 30 is located Between the outer peripheral surface 211 of the main body 21 and the second magnet 31 and the third magnet 32.

According to an embodiment of the present invention, the air gap gap is not a fixed size, it has a maximum air gap and a minimum air gap, and the maximum air gap is 2-6 times the minimum air gap.

According to the embodiment of the present invention, there is an included angle Theta between the second magnet 31 and the third magnet 32, and the included angle Theta is 100 to 120 degrees.

Following the above, in the preferred embodiment, the included angle Theta is 105 degrees.

According to an embodiment of the present invention, the first magnet 30 has a first thickness T1 in the radial direction of the rotor 20, the second magnet 31 has a second thickness T2 in the radial direction of the rotor 20, and the third The magnet 32 has a third thickness T3 in the radial direction of the rotor 20, and the second thickness T2 and the third thickness T3 are both greater than or equal to the first thickness T1.

Following the above, in the preferred embodiment, the diameter of the body 21 of the rotor 20 is 95mm, the first thickness T1 is 3.5mm, the second thickness T2 is 3.5mm, and the third thickness T3 is 3.5mm. The second thickness T2 and the third thickness T3 may be greater than or equal to the first thickness T1.

According to an embodiment of the present invention, the first magnet 30 has a first width W1 in the vertical direction of the first thickness T1, the second magnet 31 has a second width W2 in the vertical direction of the second thickness T2, and the The third magnet 32 has a third width W3 in the vertical direction of the third thickness T3, and the second width W2 and the third width W3 are both greater than or equal to the first width W1.

Following the above, in the preferred embodiment, the first width W1 is 14mm, the second width W2 is 14mm, and the third width W3 is 14mm. The aforementioned second width W2 and the third width W3 may be greater than or equal to The first width W1.

According to the embodiment of the present invention, there is a first distance D1 between the outer peripheral surface 211 of the main body 21 and the first magnet 30, and the first magnet 30 is connected to the second magnet 31 and the third magnet 32. There is a second distance D2 therebetween, a third distance D3 between the second magnet 31 and the third magnet 32, and the third distance D3 is smaller than the first thickness T1.

FIG. 3 is a schematic diagram of torque ripple of the permanent magnet motor of the present invention when the first pitch is 3 to 8 times the air gap, and the second pitch and the first thickness are at different ratios. In order to analyze the ratio of the first distance D1 to the air gap gap (D1/gap), and the ratio of the second distance D2 to the first thickness T1 (D2/T1), the torque ripple of the permanent magnet motor Influence, in the simulation analysis, the value of the first distance D1 and the second distance D2 is a variable number to observe its influence on the output performance of the permanent magnet motor. After simulation analysis, it is found that when the ratio of the first distance D1 to the air gap gap is greater than 4 (that is, D1/gap=5 or more), the permanent magnet motor will produce a larger torque ripple, and in Fig. 3 Region A has the smallest torque ripple, and its torque ripple is less than 3%. It can be known from the foregoing analysis results that when the first distance D1 is 3 to 4 times the air gap gap, and the second distance D2 is 2.4 to 2.6 times the first thickness T1, the permanent magnet motor can be reduced Torque ripple.

4 is a schematic diagram of output torque at different ratios between the second distance and the first thickness when the first distance of the permanent magnet motor of the present invention is 3 to 8 times the air gap. Following the analysis result of Fig. 3, in the area B of Fig. 4, the output torque can be increased by 3~5% compared with other output torques. Therefore, it can be known that when the first distance D1 is 3 to 4 times of the air gap gap, and the second distance D2 is 2.4 to 2.6 times of the first thickness T1, the output torque of the permanent magnet motor can be improved. .

In summary, when the first distance D1 is 3 to 4 times the air gap gap, and the second distance D2 is 2.4 to 2.6 times the first thickness T1, the generation of torque ripple can be reduced. It can smooth the torque and increase the output torque, thereby improving the performance and stability of the permanent magnet motor.

Although the present invention has been disclosed as above in a preferred embodiment, it is not intended to limit The present invention, anyone who is familiar with this technology, can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to those defined by the appended patent scope.

10: Stator

20: Rotor

21: body

211: Outer peripheral surface

30: The first magnet

31: The second magnet

32: The third magnet

Claims (10)

A permanent magnet motor includes: A stator and a rotor, the rotor is installed in the stator, and the rotor can rotate relative to the stator, wherein the rotor includes a body, and an outer peripheral surface is formed on the outer side of the body, and the outer peripheral surface and the stator Has an air gap; and The main body is embedded with a plurality of first magnets, a plurality of second magnets, and a plurality of third magnets, which are arranged radially on the main body. The second magnet and the third magnet are symmetrically placed on the first magnet. On both sides of the magnet, and the first magnet is located between the outer peripheral surface of the body, the second magnet and the third magnet. The permanent magnet motor according to claim 1, wherein the air gap is not a fixed size, it has a maximum air gap and a minimum air gap, and the maximum air gap is 2-6 times the minimum air gap. The permanent magnet motor according to claim 1, wherein there is an included angle between the second magnet and the third magnet, and the included angle is 100 to 120 degrees. The permanent magnet motor of claim 1, wherein the first magnet has a first thickness in the radial direction of the rotor, the second magnet has a second thickness in the radial direction of the rotor, and the third magnet There is a third thickness in the radial direction of the rotor, and both the second thickness and the third thickness are greater than or equal to the first thickness. The permanent magnet motor according to claim 1, wherein the first magnet has a first width in a direction perpendicular to the first thickness, the second magnet has a second width in a direction perpendicular to the second thickness, and the first magnet The three magnets have a third width in the vertical direction of the third thickness, and the second width and the third width are both greater than or equal to the first width. The permanent magnet motor of claim 1, wherein there is a first distance between the outer peripheral surface of the body and the first magnet, and a second distance is provided between the first magnet, the second magnet, and the third magnet. There is a third distance between the second magnet and the third magnet, and the third distance Less than the first thickness. A permanent magnet motor includes: A stator and a rotor, the rotor is installed in the stator, and the rotor can rotate relative to the stator, wherein the rotor includes a body, and an outer peripheral surface is formed on the outer side of the body, and the outer peripheral surface and the stator Has an air gap; and The main body is embedded with a plurality of first magnets, a plurality of second magnets, and a plurality of third magnets, which are arranged radially on the main body. The second magnet and the third magnet are symmetrically placed on the first magnet. Two sides of the magnet, and the first magnet is located between the outer peripheral surface of the body, the second magnet and the third magnet; Wherein, there is a first distance between the outer peripheral surface of the body and the first magnet, and the first distance is 3 to 4 times the air gap; the first magnet, the second magnet, and the third magnet There is a second distance therebetween, the first magnet has a first thickness in the radial direction of the rotor, and the second distance is 2.4 to 2.6 times the first thickness. The permanent magnet motor according to claim 7, wherein the second magnet has a second thickness in the radial direction of the rotor, the third magnet has a third thickness in the radial direction of the rotor, and the second magnet Both the thickness and the third thickness are greater than or equal to the first thickness. The permanent magnet motor according to claim 7, wherein the first magnet has a first width in a direction perpendicular to the first thickness, the second magnet has a second width in a direction perpendicular to the second thickness, and the first magnet The three magnets have a third width in the vertical direction of the third thickness, and the second width and the third width are both greater than or equal to the first width. The permanent magnet motor according to claim 7, wherein there is a third distance between the second magnet and the third magnet, and the third distance is smaller than the first thickness.

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