Rotor structure and motor

Abstract

The present invention provides a rotor structure and motor. The rotor structure includes a body having a slot group, the slot group including at least three mounting slots, the multiple mounting slots of the slot group being spaced apart radially along the body, and the area between any two adjacent mounting slots of the slot group forming a magnetic channel. The body has a preset symmetric centerline that divides each mounting slot into two symmetrical parts. On the symmetric centerline and in the direction from the axial hole toward the outer edge of the body, the widths of the multiple mounting slots of the slot group are L1, L2…L(n), and the widths of the multiple magnetic channels are W1, W2…W(n-1), respectively. 1.5≤(L1+L2+…+L(n)) / (W1+W2+…+W(n-1))≤1.7. This solution, through the rational configuration of different mounting slot and magnetic channel widths, not only achieves higher efficiency under light loads, but also overcomes the oversaturation of the cross-axis magnetic channels caused by high current under heavy loads, thereby improving the motor's overload capacity and efficiency under various operating conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to a rotor structure and a motor. Background Art

[0002] The existing two-layer magnetic barrier permanent magnet assisted synchronous reluctance motor has the characteristics of high efficiency due to the extensive use of reluctance torque. However, under high torque conditions, the cross-axis inductance drops sharply due to the saturation of the cross-axis magnetic conduction channel, resulting in low overload capacity and rapid efficiency decay, resulting in low heavy load efficiency. Summary of the Invention

[0003] The present invention provides a rotor structure and a motor to improve the efficiency of the motor.

[0004] To achieve the above-mentioned objective, according to one aspect of the present invention, a rotor structure is provided, comprising: a body, the body having a slot group, the slot group comprising at least three mounting slots, the multiple mounting slots of the slot group being spaced apart along the radial direction of the body, both ends of the mounting slot extending toward the outer edge of the body, the middle of the mounting slot protruding toward the axial hole of the body, and the area between any two adjacent mounting slots of the slot group being a magnetic conductive channel; the body having a preset symmetry center line, the symmetry center line dividing each mounting slot into two symmetrical parts; on the symmetry center line and in the direction from the axial hole to the outer edge of the body, the widths of the multiple mounting slots of the slot group are L1, L2…L(n) in sequence, and the widths of the multiple magnetic conductive channels are W1, W2…W(n-1) in sequence; 1.5≤(L1+L2+…+L(n)) / (W1+W2+…+W(n-1))≤1.7.

[0005] Furthermore, each of the mounting grooves has an inner arc line and an outer arc line, the inner arc line is arranged close to the axial hole relative to the outer arc line, and the centers of each inner arc line and each outer arc line are located on the symmetry center line; on the symmetry center line and in the direction from the axial hole to the outer edge of the main body, the inner arc line radius of the x-th mounting groove is r(2x-1), and the outer arc line radius is r(2x); the size of the x-th mounting groove satisfies: r(2x)<r(2x-1), x=1, 2…(n-1); on the symmetry center line and in the direction from the axial hole to the outer edge of the main body, the inner arc line radius of the mounting groove farthest from the axial hole is r(2n-1), and the outer arc line radius is r(2n), and r(2n-1)<r(2n).

[0006] Furthermore, the radius of the body is R, and the rotor structure satisfies: 0.35R≤(L1+L2+…+L(n)+W1+W2+…+W(n-1))≤0.5R.

[0007] Furthermore, the widths of the plurality of magnetic conductive channels satisfy: W1≥W2≥…≥W(n-1).

[0008] Furthermore, among the widths of the plurality of mounting slots of the slot group, L1 has the largest value and L(n) has the smallest value.

[0009] Furthermore, the magnetic conductive channel closest to the axial hole and the mounting grooves on both sides thereof satisfy: 0.3≤W1 / (L1+L2)≤0.5; and / or, the magnetic conductive channel farthest from the axial hole and the mounting grooves on both sides thereof satisfy: 0.3≤W(n-1) / (L(n-1)+L(n))≤0.5.

[0010] Furthermore, the number of the mounting slots in the slot group is 3 to 6.

[0011] Furthermore, the rotor structure further includes: a plurality of ferrite permanent magnets, and the plurality of ferrite permanent magnets are arranged in the plurality of mounting slots in a one-to-one correspondence.

[0012] Furthermore, the main body has a plurality of the groove groups, and the plurality of the groove groups are distributed in a one-to-one correspondence on a plurality of fan-shaped areas of the main body, and the arc of each fan-shaped area is a minor arc.

[0013] According to another aspect of the present invention, a motor is provided, comprising the above-mentioned rotor structure.

[0014] The technical solution of the present invention is applied to provide a rotor structure, which includes a body, a slot group, and the slot group includes at least three mounting slots. The multiple mounting slots of the slot group are arranged at intervals along the radial direction of the body, and both ends of the mounting slots are extended toward the outer edge of the body. The middle of the mounting slot is protruded toward the axial hole of the body, and the area between any two adjacent mounting slots of the slot group is a magnetic channel; the body has a preset symmetry center line, and the symmetry center line divides each mounting slot into two symmetrical parts; on the symmetry center line and in the direction from the axial hole to the outer edge of the body, the widths of the multiple mounting slots of the slot group are L1, L2...L(n) in sequence, and the widths of the multiple magnetic channels are W1, W2...W(n-1) in sequence; 1.5≤(L1+L2+...+L(n)) / (W1+W2+...+W(n-1))≤1.7. By adopting this solution, through the reasonable configuration of different installation slots and magnetic channel widths, it not only has higher efficiency under light load, but also overcomes the oversaturation phenomenon of the cross-axis magnetic channel caused by large current under heavy load, thereby improving the motor's overload capacity and the efficiency of the motor in various working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0016] Figure 1 A schematic structural diagram of a rotor structure provided by an embodiment of the present invention is shown;

[0017] Figure 2 Shown Figure 1 A partial enlarged view of the rotor structure;

[0018] Figure 3 The relationship between the inductance of the quadrature and direct axes and the number of mounting slot layers (i.e., the number of mounting slots) is shown;

[0019] Figure 4 The relationship between the number of installation slot layers and the main parameters is shown.

[0020] The above drawings include the following reference numerals:

[0021] 10. Main body; 11. Mounting slot; 12. Magnetic channel; 20. Ferrite permanent magnet. DETAILED DESCRIPTION

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative work are within the scope of protection of the present invention.

[0023] As shown in the accompanying drawings, an embodiment of the present invention provides a rotor structure, comprising: a body 10, the body 10 having a slot group, the slot group including at least three mounting slots 11, the multiple mounting slots 11 of the slot group being spaced apart along the radial direction of the body 10, both ends of the mounting slots 11 extending toward the outer edge of the body 10, the middle portion of the mounting slot 11 protruding toward the axial hole of the body 10, and the area between any two adjacent mounting slots 11 of the slot group being a magnetic conductive channel 12; the body 10 having a preset symmetry centerline, the symmetry centerline dividing each mounting slot 11 into two symmetrical parts; on the symmetry centerline and in the direction from the axial hole toward the outer edge of the body 10, the widths of the multiple mounting slots 11 of the slot group are L1, L2...L(n), and the widths of the multiple magnetic conductive channels 12 are W1, W2...W(n-1), respectively; 1.5≤(L1+L2+...+L(n)) / (W1+W2+...+W(n-1))≤1.7.

[0024] The technical solution of the present invention is applied to provide a rotor structure, which includes a body 10, the body 10 has a slot group, the slot group includes at least three mounting slots 11, the multiple mounting slots 11 of the slot group are arranged at intervals along the radial direction of the body 10, both ends of the mounting slots 11 extend toward the outer edge of the body 10, the middle of the mounting slot 11 protrudes toward the axial hole of the body 10, and the area between any two adjacent mounting slots 11 of the slot group is a magnetic channel 12; the body 10 has a preset symmetry center line, which divides each mounting slot 11 into two symmetrical parts; on the symmetry center line and in the direction from the axial hole to the outer edge of the body 10, the widths of the multiple mounting slots 11 of the slot group are L1, L2...L(n) in sequence, and the widths of the multiple magnetic channels 12 are W1, W2...W(n-1) in sequence; 1.5≤(L1+L2+...+L(n)) / (W1+W2+...+W(n-1))≤1.7. By adopting this solution, through the reasonable configuration of different installation slots 11 and the width of the magnetic channel 12, not only can it have higher efficiency under light load, but it can also overcome the oversaturation phenomenon of the cross-axis magnetic channel 12 caused by large current under heavy load, thereby improving the motor's overload capacity and the efficiency of the motor in various working conditions.

[0025] In this embodiment, each mounting groove 11 has an inner arc and an outer arc, the inner arc is arranged close to the axial hole relative to the outer arc, and the centers of each inner arc and each outer arc are located on the symmetric center line; on the symmetric center line and in the direction from the axial hole to the outer edge of the main body 10, the inner arc radius of the x-th mounting groove 11 is r(2x-1), and the outer arc radius is r(2x); the size of the x-th mounting groove 11 satisfies: r(2x)<r(2x-1), x=1, 2…(n-1); on the symmetric center line and in the direction from the axial hole to the outer edge of the main body 10, the inner arc radius of the mounting groove 11 farthest from the axial hole is r(2n-1), and the outer arc radius is r(2n), r(2n-1)<r(2n).

[0026] In this embodiment, the radius of the body 10 is R, and the rotor structure satisfies: 0.35R≤(L1+L2+…+L(n)+W1+W2+…+W(n-1))≤0.5R.

[0027] In this embodiment, the widths of the plurality of magnetic conductive channels 12 satisfy: W1 ≥ W2 ≥ . . . ≥ W(n-1).

[0028] In this embodiment, among the widths of the plurality of mounting slots 11 of the slot group, L1 has the largest value and L(n) has the smallest value.

[0029] In this embodiment, the magnetic conductive channel 12 closest to the axial hole and the mounting grooves 11 on both sides thereof satisfy: 0.3≤W1 / (L1+L2)≤0.5; and / or, the magnetic conductive channel 12 farthest from the axial hole and the mounting grooves 11 on both sides thereof satisfy: 0.3≤W(n-1) / (L(n-1)+L(n))≤0.5.

[0030] In this embodiment, the rotor structure further includes: a plurality of ferrite permanent magnets 20, which are disposed in a one-to-one correspondence within a plurality of mounting slots 11. The ferrite permanent magnets 20 embedded in the mounting slots 11 have low remanence and thus generate low permanent magnet torque. The multi-layer structure formed by the multiple mounting slots significantly increases the reluctance torque of the motor, thereby increasing the output torque and achieving higher motor efficiency.

[0031] In order to facilitate understanding of this solution, a detailed description is given below.

[0032] Under high torque conditions, excessive operating current causes the magnetic field of the magnetic channel 12 formed by the mounting slots 11 to saturate, causing the motor's quadrature-axis inductance to drop sharply, resulting in excessive current, increased motor copper loss, rapid motor efficiency decay, and low efficiency under heavy loads. Generally, as the number of mounting slots 11 increases, the number of magnetic channels 12 also increases. The saturation of a magnetic channel 12 reduces the impact on the inductance of the entire motor, limiting the increase in motor current, and improving the motor's efficiency when the motor is overloaded. The magnetic channel 12 can also be understood as a magnetic circuit.

[0033] like Figure 3 As shown, under the action of the same large current, the saturation degree of the corresponding magnetic channel 12 of different layers of mounting slots 11 is different, which is manifested as the difference in salient pole ratio (the difference between the quadrature-axis inductance and the direct-axis inductance). A large salient pole ratio can produce a larger output torque and improve the efficiency of the motor. As can be seen from the figure, the number of layers n of the mounting slots 11 is preferably between 3 and 6. Compared with the traditional two-layer mounting slot 11 structure rotor, the use of this rotor structure can greatly improve the heavy-load efficiency of the motor. This solution rationally configures the width of the mounting slot 11 and the corresponding width of the magnetic channel 12, maximizes the improvement of the heavy-load efficiency of the motor, improves the overall efficiency of the motor, and reduces the amount of permanent magnets, saving costs.

[0034] In a motor using this rotor structure, the magnetic field generated by the stator passes through the rotor structure and interacts with the magnetic field of the permanent magnet embedded in the mounting slot 11 to generate a permanent magnet torque; due to the position and shape of the mounting slot 11, the inductance in different flow directions is different, resulting in a magnetic resistance torque. Therefore, the width of the magnetic channel 12 and the width of the mounting slot 11 directly affect the inductance in different flow directions. The direction along the permanent magnet, that is, the direction of the symmetrical midline from inside to outside is defined as the direct axis, and the direction along the magnetic channel 12 from inside to outside is defined as the quadrature axis. The inductance generated by the stator magnetic field flowing through the direct axis and quadrature axis is the direct-axis inductance and the quadrature-axis inductance. The difference between them is called the salient pole ratio, which determines the motor efficiency.

[0035] In the rotor structure, the width of the magnetic channel 12 and the mounting slot 11 need to be reasonably chosen to obtain a higher salient pole ratio. If the width of the magnetic channel 12 is too small, it is easy to cause its magnetic density distribution to be excessive, resulting in magnetic saturation, thereby reducing the quadrature-axis inductance and the salient pole ratio. If the magnetic channel 12 is too large, it will naturally cause the width of the mounting slot 11 to be too small, increase the direct-axis inductance, and reduce the salient pole ratio. Therefore, there is an optimal range for the motor salient pole ratio. Figure 4 It can be seen that for a rotor structure with n layers of mounting slots 11, 1.5≤(L1+L2+…+L(n)) / (W1+W2+…+W(n-1))≤1.7 must be satisfied. The effects of both factors can be combined to improve the efficiency of the motor under heavy load.

[0036] In the present application, the rotor structure has a multi-layer mounting groove 11, and its mounting groove 11 is based on a certain rotor size. The width of the mounting groove 11 and the magnetic channel 12 is restricted by the rotor diameter. In the magnetic field flow area on the entire rotor, the area other than the magnetic channel 12 has little effect on the quadrature and direct axes. Therefore, in order to obtain a better salient pole ratio and higher motor efficiency, the part of the mounting groove 11 dividing the entire rotor radius satisfies 0.35R≤(L1+L2+…+L(n)+W1+W2+…+W(n-1))≤0.5R, where R is the outer diameter of the body.

[0037] Furthermore, under the action of large current, the corresponding magnetic conductive channel 12 undergoes magnetic saturation. As the number of layers increases, the magnetic field shared by the newly formed magnetic conductive channel 12 gradually weakens. Therefore, the width of the newly formed magnetic conductive channel 12 is set to be smaller and smaller, that is, W1≥W2≥…≥W(n-1) is satisfied, which can reasonably share the overall magnetic field of the motor in the stator magnetic field runoff rotor path, and minimize the attenuation of the salient pole ratio.

[0038] Furthermore, the rotor structure has corresponding embedded ferrite permanent magnets, which are connected in series in the motor magnetic channel 12 from the inside to the outside. For a certain layer of permanent magnets, the vast majority of its magnetic field is connected in series with the permanent magnets outside it and interlinks with the stator magnetic field; a small portion of the magnetic field directly enters the air gap and interlinks with the stator magnetic field. In order to adjust the permanent magnets in two adjacent installation slots 11 and the magnetic channel 12 formed by them to achieve a reasonable configuration of the series magnetic field distribution, there is a better, for n-layer structure, satisfying 0.3≤W(n-1) / (L(n-1)+L(n))≤0.5.

[0039] Optionally, to improve motor efficiency, the mounting slot 11 and its corresponding permanent magnet are configured as an arc-shaped structure, wide in the middle and narrow at the ends. Specifically, the radial width of the mounting slot 11 is greatest at its midline of symmetry, gradually decreasing toward its ends. Specifically, for the mounting slot 11 numbered x, the corresponding inner arc radius is r(2x-1), and the outer arc radius is r(2x), where x = 1, 2, ... (n-1). To reduce costs and the number of permanent magnets used, the arc radius of the outermost mounting slot 11 satisfies the following: r(2n-1) < r(2n).

[0040] In this embodiment, the main body 10 has a plurality of slot groups, and the plurality of slot groups are distributed in a one-to-one correspondence on a plurality of sector-shaped areas of the main body 10 , and the arcs of each sector-shaped area are all minor arcs.

[0041] Another embodiment of the present invention provides a motor, which includes the above-mentioned rotor structure. The motor adopting this solution has a reasonable configuration of the width of the installation slots 11 with different layers, which not only has a higher efficiency under light load, but also overcomes the oversaturation phenomenon of the cross-axis magnetic channel 12 caused by large current under heavy load, thereby improving the motor overload capacity and the efficiency of each working condition of the motor. At the same time, it saves the amount of permanent magnets and reduces costs. The motor and equipment using the patented technology propose a configuration relationship between the magnetic channel 12 and the magnetic isolation bridge part, which can effectively improve the defect of easy demagnetization due to the use of ferrite permanent magnets, improve the reliability of the motor, and further reduce the electromagnetic force of the motor, reduce the electromagnetic vibration caused by the excessive amplitude of the electromagnetic force, and reduce electromagnetic noise.

[0042] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A rotor structure, characterized in that: include: A body (10), wherein the body (10) has a slot group, the slot group includes at least three mounting slots (11), the plurality of mounting slots (11) of the slot group are arranged at intervals along the radial direction of the body (10), both ends of the mounting slots (11) are extended toward the outer edge of the body (10), the middle of the mounting slot (11) is protruded toward the axial hole of the body (10), and the area between any two adjacent mounting slots (11) of the slot group is a magnetic conductive channel (12); The body (10) has a preset symmetrical center line, and the symmetrical center line divides each of the mounting slots (11) into two symmetrical parts; On the symmetrical midline and in the direction from the axial hole to the outer edge of the body (10), the widths of the plurality of mounting slots (11) of the slot group are sequentially L1, L2...L(n), and the widths of the plurality of magnetic conductive channels (12) are sequentially W1, W2...W(n-1); 1.5≤(L1+L2+…+L(n)) / (W1+W2+…+W(n-1))≤1.7; The magnetic conductive channel (12) closest to the shaft hole and the mounting grooves (11) on both sides thereof satisfy: 0.3≤W1 / (L1+L2)≤0.5; and / or the magnetic conductive channel (12) farthest from the shaft hole and the mounting grooves (11) on both sides thereof satisfy: 0.3≤W(n-1) / (L(n-1)+L(n))≤0.

5.

2. The rotor structure according to claim 1, characterized in that: Each of the mounting grooves (11) has an inner arc line and an outer arc line, the inner arc line is arranged close to the shaft hole relative to the outer arc line, and the centers of each of the inner arc line and each of the outer arc lines are located on the symmetry center line; On the symmetric midline and in the direction from the axial hole to the outer edge of the body (10), the inner arc radius of the x-th installation groove (11) is r(2x-1), and the outer arc radius is r(2x); the size of the x-th installation groove (11) satisfies: r(2x)<r(2x-1), x=1, 2...(n-1); On the symmetry center line and in the direction from the axial hole to the outer edge of the body (10), the inner arc radius of the mounting groove (11) farthest from the axial hole is r(2n-1), and the outer arc radius is r(2n), and r(2n-1)<r(2n).

3. The rotor structure according to claim 1, characterized in that: The radius of the body (10) is R, and the rotor structure satisfies: 0.35R≤(L1+L2+…+L(n)+W1+W2+…+W(n-1))≤0.5R.

4. The rotor structure according to claim 1, characterized in that The widths of the plurality of magnetic conductive channels (12) satisfy: W1≥W2≥…≥W(n-1).

5. The rotor structure according to claim 1, characterized in that: Among the widths of the plurality of mounting slots (11) of the slot group, L1 has the largest value and L(n) has the smallest value.

6. The rotor structure according to claim 1, characterized in that The number of the mounting slots (11) in the slot group is 3 to 6.

7. The rotor structure according to claim 1, characterized in that The rotor structure further comprises: A plurality of ferrite permanent magnets (20) are arranged in a one-to-one correspondence within the plurality of mounting slots (11).

8. The rotor structure according to claim 1, characterized in that The body (10) has a plurality of groove groups, and the plurality of groove groups are distributed one-to-one on a plurality of fan-shaped areas of the body (10), and the arc of each fan-shaped area is a minor arc.

9. A motor, characterized in that: The electric motor comprises the rotor structure according to any one of claims 1 to 8.

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