Permanent magnet composite array configuration and permanent magnet motor

Abstract

According to the permanent magnet composite array configuration and the permanent magnet motor, a rotor magnet yoke and a permanent magnet pole matrix composed of a plurality of permanent magnet poles are arranged, the magnetization directions of the two permanent magnet poles adjacent in the transverse direction of the rotor magnet yoke are opposite, and the magnetization directions of the two permanent magnet poles adjacent in the axial direction of the rotor magnet yoke are opposite; the distribution mode that the magnetization directions of the permanent magnet poles change periodically is formed, the expected single-side magnetic field enhancement effect can be further achieved on the basis of achieving a closed magnetic circuit, the magnetic field utilization rate is effectively improved through the permanent magnet composite array structure, back magnetic leakage is reduced, the air gap flux density and the smoothness of the magnetic field gradient are improved, and the magnetic field enhancement effect is improved. Therefore, the thrust density or the torque density of the motor is obviously improved.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to a permanent magnet composite array configuration and a permanent magnet motor. Background Art

[0002] Currently, permanent magnet motors used in humanoid robot linear actuators typically adopt conventional slotted permanent magnet motors. The magnetic saturation of the slotted iron core severely restricts the instantaneous high overload capacity of the permanent magnet motor. When the permanent magnet motor runs at high speed, the core loss of the teeth will become the main source of energy consumption. In addition, the large motor winding inductance of the slotted permanent magnet motor leads to a large electrical time constant, which also affects the dynamic response performance of the permanent magnet motor.

[0003] The slotless permanent magnet motor eliminates the magnetic teeth on the stator. This type of permanent magnet motor has undergone major changes in structural principles, design and analysis, and manufacturing processes. Compared with traditional permanent magnet motors, it has the following advantages: the stator tooth core loss is greatly reduced when the motor is in high-speed state; the armature winding inductance is generally in the microhenry level, with small inductance and small electrical time constant, so the dynamic response is fast; under the condition of good heat dissipation of the stator winding, the motor has a strong overload capacity, and the current can reach more than 10 times the rated value without causing magnetic saturation.

[0004] However, in general, the slotless permanent magnet motor has a larger air gap and increased magnetic resistance due to the lack of teeth, resulting in a small air gap magnetic density. The current density of the winding required to produce the same motor torque is large. Therefore, it is necessary to use special permanent magnet motor design methods and special manufacturing processes to improve the motor air gap magnetic density.

[0005] The Halbach permanent magnet array is a common permanent magnet array structure. It has the characteristics of sinusoidal and magnetic shielding. It can also provide a larger air gap magnetic flux density fundamental wave amplitude and a lower air gap magnetic flux density harmonic distortion rate, significantly improving the power density of the permanent magnet motor, reducing torque fluctuations, and reducing harmonic losses. Therefore, it can be used preferentially in high power density permanent magnet motors.

[0006] The Halbach array structure works by combining tangentially and normally magnetized permanent magnets, converging magnetic field lines on one side and weakening them on the other, thereby achieving a relatively ideal unilateral magnetic field. Applying this structure to motor rotor design not only increases air gap magnetic field strength but also reduces core losses and yoke thickness, thereby increasing the motor's torque density and improving its dynamic response. However, the Halbach array, composed of rectangular permanent magnets, has limited shielding effectiveness, still experiencing significant magnetic flux leakage and high magnetic field losses. Summary of the Invention

[0007] The technical problem to be solved by the present invention is how to overcome the technical shortcomings of existing Halbach permanent magnet arrays, which suffer from significant magnetic flux leakage and high magnetic field losses. To overcome these shortcomings of the prior art, the present invention provides a permanent magnet composite array configuration and a permanent magnet motor, specifically comprising a permanent magnet composite array configuration and a permanent magnet motor.

[0008] The present invention provides a permanent magnet composite array configuration, including a rotor yoke and a magnetic pole array arranged on the rotor yoke. The magnetic pole array is a permanent magnet pole matrix composed of a plurality of permanent magnet poles arranged at equal intervals. The magnetization directions of two permanent magnet poles adjacent to each other in the transverse direction of the rotor yoke are arranged in opposite directions, and the magnetization directions of two permanent magnet poles adjacent to each other in the axial direction of the rotor yoke are arranged in opposite directions.

[0009] The permanent magnet composite array configuration disclosed in the present invention, by providing a rotor yoke and a permanent magnet pole matrix composed of multiple permanent magnet poles, wherein the magnetization directions of two adjacent permanent magnet poles along the rotor yoke are opposite, and the magnetization directions of two adjacent permanent magnet poles along the axial direction of the rotor yoke are opposite, forming a distribution pattern in which the magnetization directions of the permanent magnet poles vary periodically. On the basis of achieving a closed magnetic circuit, the desired unilateral magnetic field enhancement effect can be further achieved. This permanent magnet composite array configuration effectively improves the magnetic field utilization rate, reduces back leakage, and improves the smoothness of the air gap flux density and magnetic field gradient, thereby significantly improving the thrust density or torque density of the motor. The overall structure has the advantages of optimized magnetic properties and high structural stability, and is suitable for various high-performance permanent magnet motors, especially for coreless structures with high requirements for flux density and sensitive dynamic performance.

[0010] In a possible implementation, the rotor yoke and the permanent magnet poles are connected by gluing or magnetic slot pressing, thereby being able to withstand the centrifugal force or reaction force during the operation of the motor.

[0011] In a possible implementation, the rotor yoke is made of a magnetically conductive material; thereby not only the permanent magnetic poles can be fixedly installed, but also the magnetic circuit can be closed.

[0012] In a possible implementation, the cross-section of the rotor yoke is rectangular, arcuate, or annular; thus, it can serve as an inner layer structure of the rotor to implement and guide an internal magnetic flux circuit of the rotor portion.

[0013] In one possible embodiment, the permanent magnetic pole includes a first main magnetic pole, a second main magnetic pole and an auxiliary magnetic pole, the first main magnetic pole and the second main magnetic pole are both arranged with an inclined magnetization direction, and the magnetization directions of the first main magnetic pole and the second main magnetic pole are mirror reflections of each other, and the magnetization direction of the auxiliary magnetic pole is arranged horizontally; since the first and second main magnetic poles can concentrate the magnetic flux in the radial outward direction of the rotor yoke through a symmetrically inclined arrangement, and the auxiliary magnetic pole strengthens the magnetic flux directionality and continuity through its horizontal magnetization direction, a high-intensity, low-harmonic magnetic field distribution is formed on one side of the radial outward direction of the rotor yoke, and the magnetic flux is offset on the other side, that is, close to the rotor yoke. This structure can realize the generation of a periodically arranged magnetic field by the permanent magnetic pole matrix, while not only effectively improving the magnetic field utilization rate and reducing back leakage, but also further improving the air gap magnetic density and the smoothness of the magnetic field gradient, thereby significantly improving the thrust density or torque density of the motor.

[0014] In a possible implementation manner, an angle between the magnetization directions of the first main magnetic pole and the second main magnetic pole is 60° to 90°.

[0015] In a possible implementation, the cross-sections of the first main magnetic pole and the second main magnetic pole are both trapezoidal in shape.

[0016] Using trapezoidal permanent magnet main poles and setting a certain magnetizing angle helps to improve the output torque capability while reducing the high-order harmonics of the air gap flux density, while meeting the linear actuator's requirements for motor output torque and torque ripple.

[0017] Another technical solution of the present invention is to provide a permanent magnet motor, wherein the rotor of the permanent magnet motor has the permanent magnet composite array configuration described in the present invention.

[0018] The permanent magnet motor disclosed in this application has a rotor with the permanent magnet composite array configuration described in the present invention. When the motor is running, the permanent magnet pole matrix mounted on the rotor yoke generates a periodically arranged magnetic field, thereby forming a high-intensity, low-harmonic magnetic field distribution on one side of the rotor radially outward, and achieving magnetic flux cancellation on the other side, i.e., near the rotor yoke. This effectively improves magnetic field utilization, reduces back leakage, and increases the smoothness of the air gap flux density and magnetic field gradient, thereby significantly improving the thrust density or torque density of the motor. The overall structure has the advantages of optimized magnetic properties and high structural stability, and is suitable for various high-performance permanent magnet motors, especially for coreless structures with high requirements for flux density and sensitive dynamic performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the permanent magnetic composite array configuration structure disclosed in Example 1 of the present application;

[0020] Figure 2Schematic diagram of the 12-pole motor rotor disclosed in Example 1 of the present application;

[0021] Figure 3 Schematic diagram of magnetic field distribution vector of the permanent magnetic composite array configuration disclosed in Example 1 of the present application;

[0022] Figure 4 A comparison diagram of the back electromotive force between the permanent magnet composite array configuration disclosed in Example 1 of the present application and the traditional rectangular Halbach array;

[0023] Figure 5 A comparison diagram of the air gap magnetic flux density between the permanent magnet composite array configuration disclosed in Example 1 of the present application and the traditional rectangular Halbach array;

[0024] Figure 6 This is a comparison chart of the air gap magnetic flux density harmonic analysis between the permanent magnet composite array configuration disclosed in Example 1 of the present application and the traditional rectangular Halbach array;

[0025] Figure 7 This is a comparison chart of the torque output of the permanent magnet composite array configuration disclosed in Example 1 of the present application and the traditional rectangular Halbach array.

[0026] Description of reference numerals:

[0027] 1. Permanent magnet pole, 11. First main magnet pole, 12. Second main magnet pole, 13. Auxiliary magnet pole, 2. Rotor yoke. DETAILED DESCRIPTION

[0028] First, those skilled in the art should understand that these embodiments are merely used to explain the technical principles of the embodiments of the present application and are not intended to limit the scope of protection of the embodiments of the present application. Those skilled in the art may adjust them as needed to suit specific application scenarios.

[0029] In the description of the embodiments of this application, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of this application based on the specific circumstances.

[0030] In the embodiments of the present application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," and "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0031] Two embodiments will be used below to further illustrate this application in detail in conjunction with the accompanying drawings and specific embodiments.

[0032] Example 1:

[0033] See also Figures 1 to 7 , the present application embodiment discloses a permanent magnetic composite array configuration, see Figure 1 and Figure 2 The permanent magnet composite array configuration includes a rotor yoke 2 and a magnetic pole array arranged on the rotor yoke 2. The magnetic pole array is composed of a plurality of permanent magnet poles 1 arranged at equal intervals, and has a permanent magnet pole matrix with at least one row and multiple columns. The magnetization directions of two permanent magnet poles 1 adjacent to each other in the transverse direction of the rotor yoke 2 (i.e., in the same row) are set in opposite directions, and the magnetization directions of two permanent magnet poles 1 adjacent to each other in the axial direction of the rotor yoke 2 are set in opposite directions.

[0034] In this embodiment, the rotor yoke 2 is used to fix the permanent magnet pole matrix and close the magnetic circuit. The rotor yoke 2 and the permanent magnet pole 1 are connected by gluing or magnetic slot pressing to withstand the centrifugal force or reaction force during the operation of the motor. The rotor yoke 2 is made of magnetic conductive material to guide the magnetic flux. The cross-section of the rotor yoke 2 is rectangular (such as Figure 1 As shown), bow (as Figure 2 shown) or annular.

[0035] The permanent magnet pole 1 is the core functional component of the structure. Figure 1 and Figure 2 In this embodiment, the permanent magnet pole 1 includes a first main magnetic pole 11, a second main magnetic pole 12 and an auxiliary magnetic pole 13 which are arranged in sequence from left to right along the transverse direction of the rotor yoke 2. The first main magnetic pole 11 and the second main magnetic pole 12 are both arranged with their magnetization directions inclined, and the magnetization directions of the first main magnetic pole 11 and the second main magnetic pole 12 are mirror-reflected to each other. Figure 1 and Figure 2 The direction indicated by the arrow in the figure is the magnetization direction. The angle between the magnetization directions of the first main magnetic pole 11 and the second main magnetic pole 12 is 60° to 90° (including the end values). The cross-sections of the first main magnetic pole 11 and the second main magnetic pole 12 are both trapezoidal. Figure 1 and Figure 2 As shown, in this embodiment, the cross-sections of the first and second main magnetic poles 11, 12 are both rectangular trapezoidal. Meanwhile, the magnetization direction of the auxiliary magnetic pole 13 is horizontal, and in this embodiment, the cross-section of the auxiliary magnetic pole 13 is triangular. Using trapezoidal permanent magnet main magnetic poles and setting a specific magnetization angle helps improve output torque capability while reducing high-order harmonics of the air gap magnetic flux density, thereby meeting the linear actuator's requirements for motor output torque and torque ripple.

[0036] Figure 3 Figure 2 is a schematic diagram of the magnetic field distribution vector of the permanent magnetic composite array configuration. Figure 3 As shown in the figure, the permanent magnet composite array configuration adopts a modular combination of main magnetic poles and auxiliary magnetic poles. The magnetization direction is reasonably designed, which effectively organizes the magnetic lines of force to form a continuous and stable magnetic flux path, thereby improving the magnetic circuit efficiency.

[0037] Figure 4 and Figure 5 Simulations of the inter-line back EMF and air gap flux density of a motor using this permanent magnet composite array configuration and a traditional rectangular Halbach array revealed that both the back EMF and air gap flux peaks of the composite permanent magnet array configuration were higher than those of the traditional rectangular Halbach permanent magnet array. The magnitude of the fundamental wave of the air gap flux density directly affects the electromagnetic torque generated by the motor. The third harmonic, a zero-sequence harmonic, is automatically suppressed and has a minimal impact. The fifth and seventh harmonics are typically the main sources of torque ripple. A larger fundamental wave of the air gap flux density results in greater torque, while smaller higher harmonics of the air gap flux density result in less torque ripple.

[0038] Figure 6 This is a comparison chart of the fundamental wave and harmonic size of the permanent magnet composite array configuration and the traditional rectangular Halbach permanent magnet array. It can be seen from the figure that the fundamental wave of the air gap magnetic density of the permanent magnet composite array configuration is significantly higher than that of the traditional rectangular Halbach permanent magnet array, and the fifth harmonic of the air gap magnetic density is significantly lower than that of the traditional rectangular Halbach array. Figure 7 The figure shows a comparison of the torque output of the motor using this permanent magnet composite array configuration and the traditional rectangular Halbach permanent magnet array. It can be seen from the figure that the output torque of the permanent magnet composite array configuration is significantly improved compared with the traditional rectangular Halbach permanent magnet array, and the torque fluctuation is significantly reduced.

[0039] In summary, the permanent magnet composite array configuration disclosed in this embodiment, by providing a rotor yoke 2 and a permanent magnet pole matrix composed of multiple permanent magnet poles 1, the magnetization directions of two permanent magnet poles 1 adjacent to each other along the lateral direction of the rotor yoke 2 are opposite, and the magnetization directions of two permanent magnet poles 1 adjacent to each other along the axial direction of the rotor yoke 2 are opposite, forming a distribution mode in which the magnetization directions of the permanent magnet poles change periodically. On the basis of achieving a closed magnetic circuit, the expected unilateral magnetic field enhancement effect can be further achieved. This permanent magnet composite array configuration effectively improves the magnetic field utilization rate, reduces back leakage, and improves the smoothness of the air gap magnetic flux and magnetic field gradient, thereby significantly improving the thrust density or torque density of the motor. The overall structure has the advantages of optimized magnetic properties and high structural stability. It is suitable for various types of high-performance permanent magnet motors, especially for coreless structures with high requirements for magnetic flux density and sensitive dynamic performance.

[0040] Example 2:

[0041] This embodiment discloses a permanent magnet motor, the rotor of which is a permanent magnet composite array configuration disclosed in one embodiment of the present invention. Slotless motors are used in humanoid robot linear actuators. Due to the lack of teeth, the air gap is large, the magnetic resistance increases, and the air gap magnetic flux density is small, making it difficult to meet the high torque required by the linear actuator. However, the rotor of the permanent magnet motor in this embodiment is a permanent magnet composite array configuration disclosed in one embodiment of the present invention. The use of trapezoidal permanent magnet main poles and the setting of a certain magnetization angle help to reduce the high harmonics of the air gap magnetic flux density while improving the output torque capacity, while meeting the linear actuator's requirements for motor output torque and torque pulsation.

[0042] In the description of the embodiments of the present application, it should be noted that in the description of the present application, terms such as "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or component must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present application.

[0043] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "in the present embodiment", "specific example", or "some examples" means that the specific features, mechanisms, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, mechanisms, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are mutually inconsistent.

[0044] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A permanent magnetic composite array configuration, characterized in that: The invention comprises a rotor yoke (2) and a magnetic pole array arranged on the rotor yoke (2), wherein the magnetic pole array is a permanent magnetic pole matrix composed of a plurality of permanent magnetic poles (1) arranged at equal intervals, wherein the magnetization directions of two permanent magnetic poles (1) adjacent to each other in the transverse direction of the rotor yoke (2) are arranged in opposite directions, and the magnetization directions of two permanent magnetic poles (1) adjacent to each other in the axial direction of the rotor yoke (2) are arranged in opposite directions.

2. The permanent magnetic composite array configuration according to claim 1, characterized in that: The rotor yoke (2) and the permanent magnetic pole (1) are connected by gluing or magnetic slot pressing.

3. The permanent magnetic composite array configuration according to claim 1 or 2, characterized in that: The rotor yoke (2) is made of magnetic conductive material.

4. The permanent magnetic composite array configuration according to claim 3, characterized in that: The cross-section of the rotor yoke (2) is in the shape of a rectangle, an arc or a ring.

5. The permanent magnetic composite array configuration according to claim 1, 2 or 4, characterized in that: The permanent magnetic pole (1) comprises a first main magnetic pole (11), a second main magnetic pole (12) and an auxiliary magnetic pole (13); the first main magnetic pole (11) and the second main magnetic pole (12) are both arranged with their magnetization directions tilted, and the magnetization directions of the first main magnetic pole (11) and the second main magnetic pole (12) are mirror-reflected and correspond to each other; the magnetization direction of the auxiliary magnetic pole (13) is arranged horizontally.

6. The permanent magnetic composite array configuration according to claim 5, characterized in that: The angle between the magnetization directions of the first main magnetic pole (11) and the second main magnetic pole (12) is 60° to 90°.

7. The permanent magnetic composite array configuration according to claim 6, characterized in that: The cross-sections of the first main magnetic pole (11) and the second main magnetic pole (12) are both trapezoidal in shape.

8. A permanent magnet motor, characterized in that: The rotor of the permanent magnet motor is of the permanent magnet composite array configuration described in any one of claims 1-7.

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