Rotor structure and motor

Abstract

The utility model discloses a rotor structure and a motor. The rotor structure comprises a rotor core and magnetic steel. Wherein the rotor iron core is provided with a plurality of groove groups, the plurality of groove groups are arranged at intervals along the circumferential direction of the rotor iron core, and each groove group comprises a first magnetic steel groove and a second magnetic steel groove which are sequentially arranged at intervals along the radial direction of the rotor iron core, the second magnetic steel grooves extend to the outer surface of the rotor core so that the second magnetic steel grooves can be communicated with the outer surface of the rotor core. The plurality of magnetic steels are respectively arranged in the first magnetic steel groove and the second magnetic steel groove. According to the invention, the problem of low motor efficiency and low motor power density of a motor with a surface-mounted structure in the prior art can be solved.

Description

Technical Field

[0001] This application relates to the field of motor technology, and more specifically, to a rotor structure and a motor. Background Technology

[0002] Permanent magnet motors are widely used in the automotive and aerospace industries due to their advantages such as fast response speed and high reliability. Currently, most aerospace motors use a surface-mount structure for their rotors, where the permanent magnets are attached to the outer surface of the rotor core. However, because the d-axis and q-axis inductances of surface-mount motors are close, they cannot provide reluctance torque, resulting in lower motor efficiency and power density. Utility Model Content

[0003] The main objective of this application is to provide a rotor structure and motor to solve the problems of low motor efficiency and low power density of surface-mount motors in the prior art.

[0004] According to one aspect of this application, a rotor structure is provided, comprising:

[0005] A rotor core having multiple slot groups spaced apart along the circumference of the rotor core, and each slot group including a first magnetic slot and a second magnetic slot arranged in a radially spaced manner along the rotor core, wherein the second magnetic slot extends to the outer surface of the rotor core so that each second slot segment communicates with the outer surface of the rotor core.

[0006] The magnets include multiple magnets, which are respectively disposed in the first magnet groove and the second magnet groove.

[0007] Furthermore, the first magnet slot includes two first slot segments arranged in a V shape, and the V-shaped sharp ends of the two first slot segments are arranged close to the center of the rotor core.

[0008] The second magnet slot is located at the V-shaped opening of the first magnet slot. The second magnet slot includes two second slot segments arranged in a V-shape, and the V-shaped sharp ends of the two second slot segments are located close to the center of the rotor core. The V-shaped opening ends of the two second slot segments extend to the outer surface of the rotor core so that each second slot segment communicates with the outer surface of the rotor core.

[0009] Wherein, the V-shaped opening angle A of the first magnet groove is smaller than the V-shaped opening angle B of the second magnet groove.

[0010] Furthermore, the rotor core is provided with an auxiliary groove, which is disposed on the outer surface of the rotor core and located between the end of the first groove segment away from the center of the rotor core and the end of the second groove segment away from the center of the rotor core.

[0011] Furthermore, along the radial direction of the rotor core, the maximum depth H of the auxiliary slot satisfies the relationship: 0.5mm≤H≤1mm.

[0012] Furthermore, the rotor core is provided with an auxiliary hole, which is located near the outer surface of the rotor core and between the end of the first slot segment away from the center of the rotor core and the end of the second slot segment away from the center of the rotor core.

[0013] Furthermore, the diameter D of the auxiliary hole satisfies the following relationship: 1mm≤D≤2mm.

[0014] Furthermore, an auxiliary groove is provided on the outer surface of the rotor core, and a protective sleeve is provided on the outer surface of the rotor core. Pads are provided between the auxiliary groove and the protective sleeve, and between the second magnet groove and the outer surface of the rotor core and the protective sleeve.

[0015] Furthermore, along the radial direction of the rotor core, the thickness T of the sheath satisfies the relationship: 1mm≤T≤3mm.

[0016] Furthermore, the sheath includes a carbon fiber binding sleeve.

[0017] On the other hand, this application also provides an electric motor, which includes the rotor structure described above.

[0018] Compared to surface-mount motors in the prior art, this application features a first magnet slot and a second magnet slot on the rotor core. Magnets are placed within these slots, creating an internal rotor structure that provides higher reluctance torque, overcoming the limitation of surface-mount motors. Furthermore, because the second magnet slot extends to the outer surface of the rotor core, connecting it to the outer surface, the magnetic bridge structure between the second magnet slot and the rotor core is eliminated, reducing magnetic leakage and effectively improving motor efficiency and power density. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0020] Figure 1 This is a schematic diagram of the rotor core structure disclosed in the embodiments of this application;

[0021] Figure 2 The appendices disclosed in the embodiments of this application Figure 1 A partial schematic diagram of the rotor core;

[0022] Figure 3 This is a schematic diagram of the rotor core with magnets and a sheath disclosed in an embodiment of this application;

[0023] Figure 4 The appendices disclosed in the embodiments of this application Figure 3 A partial schematic diagram of the rotor core.

[0024] The above figures include the following reference numerals:

[0025] 10. Rotor core; 20. Slot group; 21. First magnet slot; 211. First slot segment; 22. Second magnet slot; 221. Second slot segment; 222. Connecting point; 30. Magnet; 40. Auxiliary slot; 50. Auxiliary hole; 60. Sheath; 70. Weight reduction hole; 80. Pad; A. V-shaped opening angle of the first magnet slot; B. V-shaped opening angle of the second magnet slot; H. Maximum depth of the auxiliary slot; D. Diameter of the auxiliary hole; T. Thickness of the sheath. Detailed Implementation

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0028] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0029] As mentioned in the background section, most existing aircraft motor rotor structures employ surface-mount designs. However, due to the close proximity of the d-axis and q-axis inductances in surface-mount motors, reluctance torque cannot be provided, resulting in low motor efficiency and power density. To address this, the inventors of this application have designed a novel rotor structure that solves the problems of low motor efficiency and power density in existing surface-mount motors. The rotor structure of this application will be described in detail below with reference to the accompanying drawings.

[0030] See Figures 1 to 4 As shown, according to an embodiment of this application, a rotor structure is provided, which includes a rotor core 10 and a magnet 30.

[0031] The rotor core 10 is provided with a plurality of slot groups 20, which are spaced apart along the circumference of the rotor core 10. Each slot group 20 includes a first magnet slot 21 and a second magnet slot 22 arranged in sequence along the radial direction of the rotor core 10. The second magnet slot 22 extends to the outer surface of the rotor core 10 so that the second magnet slot 22 communicates with the outer surface of the rotor core 10. There are a plurality of magnets 30, which are respectively disposed in the first magnet slot 21 and the second magnet slot 22.

[0032] In this embodiment, multiple slot groups 20 are provided on the rotor core 10. Magnets 30 can be installed in the first magnet slot 21 and the second magnet slot 22 within each slot group 20, thereby forming multiple magnetic poles. These magnetic poles are evenly distributed along the circumference of the rotor core 10, which helps improve the uniformity of the magnetic field distribution inside the motor. Meanwhile, in the prior art, the portion of the magnet slot near the outer edge of the rotor is usually a sealed structure, forming a magnetic isolation bridge. To ensure that the magnetic flux through the magnetic bridge reaches saturation and thus limits magnetic leakage, the magnetic isolation bridge is usually made relatively narrow to achieve the magnetic isolation effect. However, because the magnetic isolation bridge is located near the outer edge of the rotor, it becomes a concentration area of ​​centrifugal force when the motor is running at high speed. The magnetic isolation bridge may undergo mechanical deformation or even break due to excessive centrifugal force. Increasing the width of the magnetic isolation bridge will increase magnetic leakage, affecting the power density of the motor. Therefore, in this embodiment, by extending the second magnet slot 22 to the outer surface of the rotor core 10, the end of the second magnet slot 22 near the rotor core 10 is made into an open structure. This eliminates the leakage magnetic field caused by the magnetic bridge through the non-magnetic bridge structure, effectively improving the motor efficiency and the power density of the motor.

[0033] In other words, compared to the surface-mount motor structure in the prior art, this embodiment has a first magnet slot 21 and a second magnet slot 22 on the rotor core 10. Magnets 30 are placed in the first magnet slot 21 and the second magnet slot 22 respectively, so that the magnets 30 are located inside the rotor, forming an internal rotor structure. This provides higher reluctance torque, compensating for the inability of surface-mount motors to provide reluctance torque. At the same time, since the second magnet slot 22 in this embodiment extends to the outer surface of the rotor core 10, connecting the second magnet slot 22 to the outer surface of the rotor core 10, this configuration eliminates the magnetic bridge structure between the second magnet slot 22 and the outer surface of the rotor core 10, reducing motor leakage and effectively improving motor efficiency and power density.

[0034] Further, see Figures 1 to 2 As shown, in this embodiment, the first magnet slot 21 includes two V-shaped first slot segments 211, with the V-shaped apex ends of the two first slot segments 211 positioned close to the center of the rotor core 10; the second magnet slot 22 is located at the V-shaped opening of the first magnet slot 21, and the second magnet slot 22 includes two V-shaped second slot segments 221, with the V-shaped apex ends of the two second slot segments 221 positioned close to the center of the rotor core 10, and the V-shaped opening ends of the two second slot segments 221 extending to the outer surface of the rotor core 10 so that each second slot segment 221 communicates with the outer surface of the rotor core 10; wherein, the V-shaped opening angle A of the first magnet slot 21 is smaller than the V-shaped opening angle B of the second magnet slot 22.

[0035] Specifically, in this embodiment, both the first magnet slot 21 and the second magnet slot 22 are V-shaped magnet slots, and the V-shaped opening angle A of the first magnet slot 21 is smaller than the V-shaped opening angle B of the second magnet slot 22. This configuration reduces the direct-axis (d-axis) inductance of the motor, making the direct-axis (d-axis) inductance different from the quadrature-axis (q-axis) inductance, thus giving the rotor a larger saliency ratio. While keeping the quadrature-axis inductance constant, this increases the reluctance torque of the motor, effectively improving motor efficiency and power density. This compensates for the deficiency of surface-mount motors where the direct-axis inductance is close to the quadrature-axis inductance and cannot provide reluctance torque. Simultaneously, since the V-shaped opening ends of the two second slot segments 221 in this embodiment extend to the outer surface of the rotor core 10, allowing each second slot segment 221 to communicate with the outer surface of the rotor core 10, this configuration allows each second magnet slot 22 to have an open structure at the end closest to the outer surface of the rotor core 10. This eliminates the leakage flux caused by the magnetic bridge through the absence of a magnetic bridge structure, further improving motor efficiency and power density.

[0036] Further, see Figure 2 As shown, in this embodiment, the rotor core 10 is provided with an auxiliary groove 40. The auxiliary groove 40 is provided on the outer surface of the rotor core 10 and is located between the end of the first groove segment 211 away from the center of the rotor core 10 and the end of the second groove segment 221 away from the center of the rotor core 10.

[0037] Specifically, the auxiliary slot 40 can improve the magnetic flux path, reduce magnetic leakage, and effectively improve the efficiency of the motor. In this embodiment, by placing the auxiliary slot 40 between the end of the first slot segment 211 furthest from the center of the rotor core 10 and the end of the second slot segment 221 furthest from the center of the rotor core 10, the distribution of magnetic flux can be better controlled, thereby improving the performance of the motor. Furthermore, in a motor, cogging torque is a type of uneven torque that causes vibration and noise. In this embodiment, by placing the auxiliary slot 40 on the outer surface of the rotor core 10 and positioning it between the end of the first slot segment 211 furthest from the center of the rotor core 10 and the end of the second slot segment 221 furthest from the center of the rotor core 10, the cogging torque can be effectively reduced, making the motor run more smoothly and significantly reducing motor noise and vibration. For example, the auxiliary slot 40 in this embodiment includes V-shaped slots, U-shaped slots, etc.

[0038] Furthermore, along the radial direction of the rotor core 10, the maximum depth H of the auxiliary slot 40 in this embodiment satisfies the relationship: 0.5mm ≤ H ≤ 1mm. For example, H can be set to 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm, 1mm, etc. When H is less than 0.5mm, the depth of the auxiliary slot 40 is shallow, making it difficult to effectively guide the magnetic flux path, resulting in uneven magnetic flux distribution, thereby reducing motor efficiency. At the same time, it cannot reduce cogging torque, increasing vibration and noise during motor operation. When H is greater than 1mm, the depth of the auxiliary slot 40 is deep. A deeper auxiliary slot 40 tends to increase the air gap in the magnetic circuit, reducing the motor's magnetic flux density, thus affecting the overall performance of the motor. In other words, by ensuring that the maximum depth H of the auxiliary slot 40 satisfies the relationship: 0.5mm ≤ H ≤ 1mm in this embodiment, not only can motor efficiency be increased, but also noise and vibration during motor operation can be reduced.

[0039] Further, see Figure 2 As shown, in this embodiment, the rotor core 10 is provided with an auxiliary hole 50. The auxiliary hole 50 is located near the outer surface of the rotor core 10 and between the end of the first slot segment 211 away from the center of the rotor core 10 and the end of the second slot segment 221 away from the center of the rotor core 10.

[0040] Specifically, the auxiliary hole 50 helps to increase the salient pole ratio of the motor, improve the air gap magnetic field waveform, reduce motor harmonics, lower motor vibration and noise, and also reduce the weight of the rotor core 10, further improving the mechanical performance during high-speed operation. Exemplarily, the auxiliary hole 50 in this embodiment includes structures such as circular holes or oblong holes. Figure 2 The case where the auxiliary hole 50 is set as a circular hole is shown.

[0041] Furthermore, in this embodiment, the aperture D of the auxiliary hole 50 satisfies the relationship: 1mm ≤ D ≤ 2mm. For example, D can be set to 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, etc. When D < 1mm, the aperture of the auxiliary hole 50 is too small, increasing the processing difficulty of the auxiliary hole 50 and easily increasing the air gap in the magnetic circuit, reducing the magnetic flux density, thereby affecting the overall performance of the motor. When D is greater than 2mm, the aperture of the auxiliary hole 50 is too large, increasing electromagnetic interference, thereby affecting the electromagnetic compatibility of the motor. That is to say, in this embodiment, by making the aperture D of the auxiliary hole 50 satisfy the relationship: 1mm ≤ D ≤ 2mm, the magnetic flux density can be improved, effectively ensuring the overall performance of the motor.

[0042] Further, see Figures 3 to 4 As shown, in this embodiment, the outer surface of the rotor core 10 is provided with an auxiliary groove 40, and the outer surface of the rotor core 10 is covered with a protective sleeve 60. A pad 80 is provided between the auxiliary groove 40 and the protective sleeve 60, and between the second magnet groove 22 and the outer surface of the rotor core 10 and the protective sleeve 60.

[0043] Specifically, the sheath 60 enhances the mechanical strength of the rotor core 10, preventing deformation or damage due to centrifugal force and effectively ensuring the stability and reliability of the motor under high speed and high load conditions. Meanwhile, since the outer surface of the rotor core 10 in this embodiment is provided with an auxiliary groove 40, and the second magnet groove 22 connects to the outer surface of the rotor core 10, when the sheath 60 is fitted onto the outer surface of the rotor core 10, the contact area between the sheath 60 and the rotor core 10 is reduced, increasing stress concentration at the auxiliary groove 40 and at the connection point 222 between the second magnet groove 22 and the outer surface of the rotor core 10. Therefore, this embodiment increases the contact area between the sheath 60 and the rotor core 10 by placing a pad 80 between the auxiliary groove 40 and the sheath 60, and between the connection point 222 between the second magnet groove 22 and the outer surface of the rotor core 10 and the sheath 60. This results in a more uniform stress distribution and prevents stress concentration on the outer surface of the rotor core 10 when the sheath 60 is fitted onto it. For example, the pad 80 in this embodiment is made of a low magnetic permeability material. Using a low magnetic permeability material avoids the formation of a closed-loop magnetic circuit, thereby reducing magnetic leakage and effectively improving the efficiency and power density of the motor.

[0044] Furthermore, along the radial direction of the rotor core 10, the thickness T of the sheath 60 in this embodiment satisfies the relationship: 1mm ≤ T ≤ 3mm. For example, T can be set to 1mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2mm, 2.2mm, 2.4mm, 2.6mm, 2.8mm, 3mm, etc. When T is less than 1mm, the thickness of the sheath 60 becomes thinner, thereby reducing the structural strength of the rotor core 10 and making it difficult to guarantee the stability and reliability of the motor under high speed and high load conditions. When T is greater than 3mm, it not only increases the overall weight of the rotor core 10 but also reduces the power density of the motor. That is to say, by ensuring that the thickness T of the sheath 60 satisfies the relationship: 1mm ≤ T ≤ 3mm in this embodiment, not only can the mechanical strength of the rotor core 10 be improved, but the power density of the motor can also be guaranteed, thereby effectively ensuring the stability and reliability of the motor under high speed and high load conditions.

[0045] Furthermore, the sheath 60 in this embodiment includes a carbon fiber binding sleeve. Specifically, since the tensile strength and stiffness of carbon fiber composite materials are 3 to 5 times that of conventional metallic materials (such as steel, aluminum, titanium, etc.), when the carbon fiber binding sleeve is fitted onto the outer surface of the rotor core 10, the structural strength and stiffness of the rotor core 10 can be improved. At the same time, due to the low density of carbon fiber material, the use of carbon fiber binding sleeves can significantly reduce the weight of the rotor core 10, thereby improving the overall efficiency and performance of the motor.

[0046] Further, see Figure 1 as well as Figure 3 As shown, the rotor core 10 in this embodiment is also provided with weight-reduction holes 70. Multiple weight-reduction holes 70 are arranged at intervals along the circumference of the rotor core 10. These holes can be equally spaced or non-equally spaced along the circumference of the rotor core 10. Specifically, the weight-reduction holes 70 are used to reduce the weight of the rotor core 10, thereby achieving a lightweight design of the rotor structure.

[0047] As can be seen from the above embodiments, the rotor structure of this application adopts an inner rotor double V-shaped topology. This rotor structure, due to its large saliency ratio, can provide higher reluctance torque, compensating for the deficiency of surface-mounted motors in providing reluctance torque due to the close proximity of direct-axis and quadrature-axis inductances. Simultaneously, by connecting the second magnet slot 22 to the outer surface of the rotor core 10, this application can further improve motor efficiency and power density based on the inner rotor double V-shaped topology. Furthermore, by providing auxiliary slots 40 and auxiliary holes 50 on the rotor core 10, noise and vibration during motor operation can be significantly reduced. In addition, by covering the outer surface of the rotor core 10 with a sheath 60, this application further enhances the mechanical structural strength of the rotor core 10, effectively ensuring the stability and reliability of the motor under high speed and high load conditions, and extending the motor's service life.

[0048] On the other hand, this application also provides an electric motor that includes the aforementioned rotor structure, and therefore, this motor incorporates all the technical effects of the aforementioned rotor structure. Since the technical effects of the rotor structure have already been described in detail above, they will not be repeated here.

[0049] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0050] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this application.

[0051] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A rotor structure, characterized in that, include: A rotor core (10) is provided with a plurality of slot groups (20). The plurality of slot groups (20) are spaced apart along the circumferential direction of the rotor core (10). Each slot group (20) includes a first magnetic slot (21) and a second magnetic slot (22) arranged in sequence along the radial direction of the rotor core (10). The second magnetic slot (22) extends to the outer surface of the rotor core (10) so that the second magnetic slot (22) communicates with the outer surface of the rotor core (10). The magnet (30) includes a plurality of magnets, and the plurality of magnets (30) are respectively disposed in the first magnet groove (21) and the second magnet groove (22).

2. The rotor structure according to claim 1, characterized in that, The first magnet slot (21) includes two first slot segments (211) arranged in a V shape, and the V-shaped sharp ends of the two first slot segments (211) are arranged close to the center of the rotor core (10); The second magnet slot (22) is located at the V-shaped opening of the first magnet slot (21). The second magnet slot (22) includes two second slot segments (221) arranged in a V-shape. The V-shaped sharp ends of the two second slot segments (221) are arranged close to the center of the rotor core (10). The V-shaped opening ends of the two second slot segments (221) extend to the outer surface of the rotor core (10) so that each second slot segment (221) communicates with the outer surface of the rotor core (10). The V-shaped opening angle A of the first magnet groove (21) is smaller than the V-shaped opening angle B of the second magnet groove (22).

3. The rotor structure according to claim 2, characterized in that, An auxiliary groove (40) is provided on the rotor core (10). The auxiliary groove (40) is provided on the outer surface of the rotor core (10) and is located between the end of the first groove segment (211) away from the center of the rotor core (10) and the end of the second groove segment (221) away from the center of the rotor core (10).

4. The rotor structure according to claim 3, characterized in that, Along the radial direction of the rotor core (10), the maximum depth H of the auxiliary groove (40) satisfies the relationship: 0.5mm≤H≤1mm.

5. The rotor structure according to claim 2, characterized in that, An auxiliary hole (50) is provided on the rotor core (10). The auxiliary hole (50) is located near the outer surface of the rotor core (10) and between the end of the first slot segment (211) away from the center of the rotor core (10) and the end of the second slot segment (221) away from the center of the rotor core (10).

6. The rotor structure according to claim 5, characterized in that, The diameter D of the auxiliary hole (50) satisfies the following relationship: 1mm≤D≤2mm.

7. The rotor structure according to any one of claims 1 to 6, characterized in that, An auxiliary groove (40) is provided on the outer surface of the rotor core (10), and a protective sleeve (60) is provided on the outer surface of the rotor core (10). A pad (80) is provided between the auxiliary groove (40) and the protective sleeve (60), and between the second magnet groove (22) and the outer surface of the rotor core (10) and the protective sleeve (60).

8. The rotor structure according to claim 7, characterized in that, Along the radial direction of the rotor core (10), the thickness T of the sheath (60) satisfies the relationship: 1mm≤T≤3mm.

9. The rotor structure according to claim 7, characterized in that, The sheath (60) includes a carbon fiber binding sleeve.

10. An electric motor, characterized in that, The motor comprises the rotor structure according to any one of claims 1 to 9.

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