Rotor structure and motor

Abstract

The invention provides a rotor structure and a motor. The rotor structure comprises a rotor core (2), the rotor core (2) is provided with filling grooves (4) and permanent magnet grooves (5), permanent magnets (6) are installed in the permanent magnet grooves (5), the filling grooves (4) are distributed on the periphery of the rotor core (2), the filling grooves (4) comprise q-axis filling grooves (42) and d-axis filling grooves (41), the q-axis filling grooves (42) comprise connecting filling grooves (43) and independent filling grooves (44), and the d-axis filling grooves (41) comprise connecting filling grooves (43) and independent filling grooves (44). The connecting filling grooves (43) and the permanent magnet grooves (5) are arranged on the same layer and are arranged at the two ends of the permanent magnet grooves (5), the independent filling grooves (44) are located between the adjacent connecting filling grooves (43), and the distances between the independent filling grooves (44) and the connecting filling grooves (43) on the two adjacent sides are different. According to the rotor structure, the efficiency of the motor can be improved, and the performance of the motor is improved.

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] Permanent magnet assisted synchronous reluctance motor has the advantages of high efficiency, high power factor, high torque density, wide response frequency, etc., and is widely used in the field of industrial motors. However, permanent magnet assisted synchronous reluctance motors require inverter control and cannot achieve self-starting. There is a self-starting problem. In addition, the inverter cost is relatively high, and the inverter itself has losses, resulting in reduced system efficiency.

[0003] Based on the permanent magnet assisted synchronous reluctance motor, the self-starting permanent magnet assisted synchronous reluctance motor combines the advantages of the asynchronous motor, realizes self-starting through the asynchronous torque generated by the rotor bars of the squirrel cage structure, and realizes constant speed operation through the permanent magnet torque and reluctance torque. Compared with the asynchronous motor, the motor can run at a constant speed with low rotor loss and high efficiency; compared with the asynchronous starting permanent magnet synchronous motor, the amount of permanent magnets is small and the motor cost is low. Compared with the permanent magnet assisted synchronous reluctance motor, it does not require a frequency converter to start, and the cost is low.

[0004] The current self-starting permanent magnet assisted synchronous reluctance motor has improved the efficiency of the motor due to the use of a permanent magnet assisted synchronous reluctance motor combined with an asynchronous motor. However, the improvement in motor efficiency is still limited, which restricts the performance of the motor. Summary of the invention

[0005] The main purpose of the present invention is to provide a rotor structure and a motor, which can improve the efficiency and performance of the motor.

[0006] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a rotor structure is provided, including a rotor core, on which filling slots and permanent magnet slots are arranged, permanent magnets are installed in the permanent magnet slots, and the filling slots are distributed on the outer circumference of the rotor core. The filling slots include q-axis filling slots and d-axis filling slots, and the q-axis filling slots include connecting filling slots and independent filling slots. The connecting filling slots are arranged on the same layer as the permanent magnet slots and are arranged at both ends of the permanent magnet slots, and the independent filling slots are located between adjacent connecting filling slots, and the spacing between the independent filling slots and the connecting filling slots on both sides are not equal.

[0007] Furthermore, under the same pole, the number of permanent magnet slots is the same as the number of permanent magnets, the number of permanent magnet slots is N, the number of filled slots is M, and 3*N<M<6*N.

[0008] Furthermore, under the same pole, the number of q-axis filling slots is M1, 3*N≤M1≤5*N, and the number of d-axis filling slots is M2, N≤M2≤3*N.

[0009] Furthermore, along the circumferential direction of the rotor core, the thickness between two adjacent connected filling slots is k1, the total thickness of the independent filling slots located on one side of the d-axis is k2, 0.15*k1≤k2≤0.5*k1, and the thickness of the connected filling slots is k3, k2≤k3.

[0010] Furthermore, in a cross section perpendicular to the central axis of the rotor core, the distance between the extension line of the side of the q-axis filling slot close to the d-axis and the center of the rotor core is L, 0.65*R≤L≤0.85*R, where R is the outer radius of the rotor core.

[0011] Furthermore, 0.7*R≤L≤0.8*R.

[0012] Furthermore, the distances between the extension lines of the sides of each q-axis filling slot close to the d-axis and the center of the rotor core are equal.

[0013] Furthermore, the distance between the extension line connecting the side of the filling slot close to the d-axis and the center of the rotor core is L1, the distance between the extension line of the side of the independent filling slot close to the d-axis and the center of the rotor core is L2, and L1≤L2.

[0014] Furthermore, the q-axis filling slot has a cut edge on one side close to the outer circle of the rotor, and the thickness of the cut edge along the circumferential direction is k31. The relationship between the thickness k31 of the cut edge and the thickness k of the q-axis filling slot where the cut edge is located satisfies 0.3*k≤k31≤0.7*k. The angle between the cut edge and the radial side edge of the q-axis filling slot where the cut edge is located is α, 120°≤α≤160°.

[0015] Furthermore, in a cross section perpendicular to the central axis of the rotor core, along the d-axis direction, the distance between the radially innermost permanent magnet slot and the center of the rotor core is H1, the distance between the radially innermost permanent magnet slot and the radially outermost permanent magnet slot is H2, and the distance between the radially outermost permanent magnet slot and the d-axis filling slot is H3, and H3<H2

[0016] Furthermore, 1.5*H2≤H1≤2.5*H2, 1.5*H3≤H2≤2.5*H3.

[0017] Furthermore, 0.82*R≤H1+H2+H3≤0.92*R, wherein R is the outer radius of the rotor core.

[0018] Furthermore, in a cross section perpendicular to the central axis of the rotor core, along the d-axis direction, the distance between the radially innermost permanent magnet slot and the radially outermost permanent magnet slot is H2, the distance between the radially innermost connecting filling slot and the radially outermost connecting filling slot is k6, and 0.8*k6≤H2≤1.2*k6.​

[0019] Furthermore, in a cross section perpendicular to the central axis of the rotor core, along the d-axis direction, the length of the radially innermost permanent magnet is s1 and the thickness is d1, and the length of the radially outermost permanent magnet is s2 and the thickness is d2, s1>s2, d2≥d1.

[0020] Furthermore, there are multiple d-axis filling slots, and in a cross section perpendicular to the central axis of the rotor core, the maximum radial width of the multiple d-axis filling slots is d3, the distance between adjacent d-axis filling slots is d4, and the maximum spacing between the two outermost d-axis filling slots in the circumferential direction is s3, 1.5*d2<d3<3*d2, d2<d4<2*d2, s3>s2.

[0021] Furthermore, there is a dividing rib between the connecting filling slot and the permanent magnet slot in the same layer. In the cross section perpendicular to the central axis of the rotor core, the thickness of the dividing rib is k4, the thickness of the connecting filling slot is k3, and 0.15*k3≤k4≤0.3*k3.

[0022] Furthermore, the distance between two connection filling grooves located on both sides of the q-axis and adjacent to the q-axis is k5, the thickness of the connection filling groove is k3, and k3≤k5≤2*k3.

[0023] Further, in a cross section perpendicular to the central axis of the rotor core, the ratio between the length of at least part of the connected filling slots along the q-axis direction and the length of the corresponding permanent magnets in the same layer is greater than 0.5.

[0024] Further, in a cross section perpendicular to the central axis of the rotor core, a ratio of the length to the thickness of the permanent magnet is less than 0.15.

[0025] Furthermore, the ratio of the length to the thickness of the permanent magnet is in the range of [0.04, 0.14].

[0026] Furthermore, along the d-axis direction, the permanent magnet located radially innermost has a length s1 and a thickness d1, and the permanent magnet located radially outermost has a length s2 and a thickness d2, and d1 / s1<d2 / s2.

[0027] Furthermore, the number of layers of the permanent magnet slots and permanent magnets is two, the permanent magnets are made of rare earth permanent magnet materials, and the permanent magnet slots, permanent magnets and filling slots are arranged symmetrically with respect to the d-axis.

[0028] Furthermore, the filling slots are filled with conductive but non-magnetic materials, and short-circuit end rings are respectively provided at both ends of the rotor core. The short-circuit end rings cover all the filling slots, short-circuit the filling slots, and form a squirrel cage structure.

[0029] Furthermore, there are multiple d-axis filling slots, and in a cross section perpendicular to the central axis of the rotor core, the maximum radial width of the multiple d-axis filling slots is d3, the outer circumference of the short-circuit end ring is an arc structure, and the inner circumference is a polygonal structure composed of straight lines and arcs, the radial width of the short-circuit end ring on the d-axis is dd1, and the radial width of the short-circuit end ring on the q-axis is dq2, and dd1≥1.5*d3.

[0030] Furthermore, dq2≥dd1.

[0031] Furthermore, 1.5*dd1≤dq2≤2*dd1.

[0032] According to another aspect of the present invention, a motor is provided, comprising a stator structure and a rotor structure, wherein the rotor structure is the above-mentioned rotor structure, and the stator structure is sleeved on the outer peripheral side of the rotor structure.

[0033] The technical solution of the present invention is applied, and the rotor structure includes a rotor core, and a filling slot and a permanent magnet slot are arranged on the rotor core. The permanent magnet slot is installed in the permanent magnet slot, and the filling slot is distributed on the outer periphery of the rotor core. The filling slot includes a q-axis filling slot and a d-axis filling slot, and the q-axis filling slot includes a connecting filling slot and an independent filling slot. The connecting filling slot and the permanent magnet slot are arranged in the same layer and arranged at both ends of the permanent magnet slot, and the independent filling slot is located between adjacent connecting filling slots, and the spacing between the independent filling slot and the connecting filling slots on both sides are unequal. The connecting filling slot and the permanent magnet slot of the rotor structure are arranged in the same layer and arranged at both ends of the permanent magnet slot, and the independent filling slot is located between adjacent connecting filling slots, and the spacing between the independent filling slot and the connecting filling slots on both sides are unequal, which can make the magnetic conductive channels on both sides of the independent filling slot have different magnetic conductive areas, so that different magnetic fluxes are allowed to pass through, and this difference can improve the torque pulsation during the operation of the motor, reduce the running noise of the motor, and reduce harmonic losses, and improve the efficiency of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0035] Figure 1 A schematic structural diagram showing a rotor structure of an embodiment of the present invention is shown;

[0036] Figure 2 A partial structural diagram of a rotor structure according to an embodiment of the present invention is shown;

[0037] Figure 3 A partial structural diagram of a rotor structure according to an embodiment of the present invention is shown;

[0038] Figure 4A schematic structural diagram showing a rotor structure of an embodiment of the present invention is shown;

[0039] Figure 5 A comparison diagram of the rotation speeds of the motor of the embodiment of the present invention and the motor of the related art during the starting process is shown;

[0040] Figure 6 A comparison diagram showing the permanent magnet operating point of the motor of the embodiment of the present invention and the motor of the related art during the starting process; and

[0041] Figure 7 The figure shows the efficiency comparison between the motor according to the embodiment of the present invention and the motor according to the related art.

[0042] The above drawings include the following reference numerals:

[0043] 1. Rotor structure; 2. Rotor core; 3. Rotor punching sheet; 4. Filling slot; 41. D-axis filling slot; 42. Q-axis filling slot; 43. Connecting filling slot; 44. Independent filling slot; 45. Cutting edge; 5. Permanent magnet slot; 51. First permanent magnet slot; 52. Second permanent magnet slot; 6. Permanent magnet; 61. First permanent magnet; 62. Second permanent magnet; 7. Shaft hole; 8. Short-circuit end ring; 9. Splitting rib. DETAILED DESCRIPTION

[0044] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0045] See also Figures 1 to 7 As shown, according to an embodiment of the present invention, the rotor structure includes a rotor core 2, on which filling slots 4 and permanent magnet slots 5 are provided, permanent magnets 6 are installed in the permanent magnet slots 5, and the filling slots 4 are distributed on the outer periphery of the rotor core 2. The filling slots 4 include q-axis filling slots 42 and d-axis filling slots 41. The q-axis filling slots 42 include connecting filling slots 43 and independent filling slots 44. The connecting filling slots 43 are arranged on the same layer as the permanent magnet slots 5 and are set at both ends of the permanent magnet slots 5. The independent filling slots 44 are located between adjacent connecting filling slots 43, and the spacing between the independent filling slots 44 and the connecting filling slots 43 on both sides are not equal.

[0046] The connecting filling slots 43 of the rotor structure are arranged on the same layer as the permanent magnet slots 5 and are set at both ends of the permanent magnet slots 5. The independent filling slots 44 are located between adjacent connecting filling slots 43. The spacing between the independent filling slots 44 and the connecting filling slots 43 on both sides are not equal, which can make the magnetic channels on both sides of the independent filling slots 44 have different magnetic conductive areas, so that the magnetic flux allowed to pass through the two sides of the independent filling slots 44 is different. This difference can reduce the cogging torque of the motor, reduce the torque pulsation during the operation of the motor, reduce the operating noise of the motor, and at the same time reduce harmonic losses and improve the motor efficiency.

[0047] The rotor structure can improve the magnetic flux density and magnetic flux utilization of the motor and reduce the cogging torque by optimizing the distribution of the filling slots 4. It is suitable for various application scenarios such as electric vehicles, industrial motors, and household appliance motors, and the performance of the motor is significantly improved.

[0048] In one embodiment, the rotor core 2 is formed by axially stacking a plurality of rotor punchings 3 , on which a plurality of filling slots 4 , a plurality of permanent magnet slots 5 and an axial hole 7 are provided, and permanent magnets 6 are inserted into the permanent magnet slots; the filling slots 4 are distributed on the outer periphery of the rotor punchings 3 .

[0049] In one embodiment, under the same pole, the number of permanent magnet slots 5 is the same as the number of permanent magnets 6 , the number of permanent magnet slots 5 is N, the number of filling slots 4 is M, and 3*N<M<6*N.

[0050] In one embodiment, under the same pole, the number of the q-axis filling slots 42 is M1, 3*N≤M1≤5*N, and the number of the d-axis filling slots 41 is M2, N≤M2≤3*N.

[0051] This design can effectively improve the starting torque of the motor by increasing the number and distribution of the filling slots 4. The filling slots 4 will form a squirrel cage effect during the asynchronous starting stage, generating asynchronous torque to help the motor accelerate from a stationary state to a synchronous speed, thereby improving the starting ability of the motor.

[0052] The number M1 of q-axis filling slots 42 satisfies 3N≤M1≤5N. Under one pole, the number of q-axis filling slots 42 is 3 to 5 times the number of permanent magnet slots 5, which helps to increase the magnetic resistance of the motor in the q-axis direction, thereby increasing the magnetic resistance torque during operation and improving the synchronous operation performance and efficiency of the motor.

[0053] The number M2 of d-axis filling slots 41 satisfies N≤M2≤3*N. At one pole, the number of d-axis filling slots 41 is 1 to 3 times the number of permanent magnet slots. The existence of d-axis filling slots 41 can improve the anti-demagnetization ability of the permanent magnet, and also reduce the amount of permanent magnets used to a certain extent, thereby reducing costs.

[0054] By optimizing the number and layout of the filling slots 4, the high starting torque requirement in the motor starting phase and the high efficiency and low cost requirements in the running phase are taken into account. In the starting phase, the squirrel cage effect is crucial to the improvement of the starting torque, while in the running phase, the rational use of the reluctance torque and permanent magnets helps to improve the efficiency of the motor and reduce the operating cost. By rationally setting the relative number and distribution of the filling slots 4 and the permanent magnet slots 5, the dual improvement of the motor starting capability and operating efficiency can be achieved.

[0055] In one embodiment, along the circumferential direction of the rotor core 2, the thickness between two adjacent connected filling slots 43 is k1, the total thickness of the independent filling slots 44 located on one side of the d-axis is k2, 0.15*k1≤k2≤0.5*k1, and the thickness of the connected filling slots 43 is k3, k2≤k3.

[0056] By adjusting the thickness and spacing of the connecting filling slots 43, the magnetic circuit design of the motor can be optimized, ensuring that an effective magnetic conductive channel is formed between the connecting filling slots 43, improving the magnetic flux density and magnetic flux utilization of the motor, reducing the cogging torque, improving the starting ability and operating efficiency of the motor, and being suitable for industrial motors that require high efficiency and high performance. Precisely limiting the thickness and spacing of the connecting filling slots and the independent filling slots can effectively improve the magnetic flux distribution inside the motor, so that the motor can use the magnetic flux more efficiently during operation, and the reduced cogging torque makes the motor run more smoothly, reduces the noise and vibration during the operation of the motor, and improves the operating efficiency and power performance of the motor.

[0057] In one embodiment, in a cross section perpendicular to the central axis of the rotor core 2 , the distance between the extension line of the side of the q-axis filling slot 42 close to the d-axis and the center of the rotor core 2 is L, 0.65*R≤L≤0.85*R, where R is the outer radius of the rotor core 2 .

[0058] The selection of this range is based on the consideration of the motor's magnetic circuit design and the optimization of the reluctance torque, aiming to ensure that the filling slot has sufficient depth to generate effective asynchronous torque when the motor starts. Specifically, the depth of the filling slot affects its conductivity during the asynchronous starting stage. The greater the depth, the longer the current path that can be formed in the filling slot, which is usually a conductive but non-magnetic material such as aluminum or copper, and the stronger the asynchronous torque generated, which helps the motor start quickly.

[0059] In one embodiment, 0.7*R≤L≤0.8*R. By further reducing the range of L, the filling slot can be designed to be closer to the radius center of the rotor core 2. Such a design can further enhance the effect of the asynchronous torque, while preventing the q-axis filling slot 42 from being too close to the rotor edge, reducing the filling slot loss, and thus maintaining the high efficiency of the motor.

[0060] In one embodiment, the distances between the extension lines of the sides of each q-axis filling groove 42 close to the d-axis and the center of the rotor core 2 are equal.

[0061] In this embodiment, one pole includes two permanent magnet slots 5, namely the first permanent magnet slot 51 and the second permanent magnet slot 52, two permanent magnets 6, namely the first permanent magnet 61 and the second permanent magnet 62, four connected filling slots 43 and two independent filling slots 44, wherein the four connected filling slots 43 are grouped into two groups, the two groups of connected filling slots 43 are symmetrical about the d-axis, and the two independent filling slots 44 are respectively located on both sides of the d-axis and are symmetrical about the d-axis.

[0062] On one side of the d-axis, along the direction away from the q-axis, the distances between the extension lines of the two connecting filling slots 43 and the side of the independent filling slot 44 close to the d-axis and the center of the rotor core 2 are L1, L2 and L3 respectively, and L1=L2=L3. L1=L2=L3 means that the distances between each q-axis filling slot 42 and the center of the rotor core are equal. Such a design can achieve a smoother and more reliable starting process of the motor. Combined with the above-mentioned definition of the relationship between L and R, it can be ensured that the q-axis filling slot 42 has a certain length in the radial direction, thereby effectively improving the starting ability of the motor.

[0063] Through this design, the motor can reach the synchronous state faster during starting, reducing the starting time. At the same time, during the starting process, the squirrel cage effect formed by the material filling the slot can protect the permanent magnet and avoid excessive demagnetization of the permanent magnet under high starting torque, ensuring the stability of the magnetic properties of the motor during starting and operation.

[0064] In one embodiment, the extension direction of the q-axis filling slot 42 is substantially parallel to the q-axis; the permanent magnet slot 5 is perpendicular to the d-axis or the two ends thereof extend substantially parallel to the q-axis.

[0065] In one embodiment, the distance between the extension line of the side of the filling slot 43 close to the d-axis and the center of the rotor core 2 is L1, and the distance between the extension line of the side of the independent filling slot 44 close to the d-axis and the center of the rotor core 2 is L2, L1≤L2.

[0066] On one side of the d-axis, along the direction away from the q-axis, the distances between the extension lines of the sides of the two connecting filling slots 43 and the independent filling slot 44 close to the d-axis and the center of the rotor core 2 are L1, L2 and L3 respectively, and L2 ≥ L1 = L3. By limiting the distances between the independent filling slot 44 and the connecting filling slot 43 and the center of the rotor core 2, a good starting effect can be achieved.

[0067] In one embodiment, the q-axis filling groove 42 has a cut edge 45 on one side close to the outer circle of the rotor, and the thickness of the cut edge 45 along the circumferential direction is k31. The relationship between the thickness k31 of the cut edge 45 and the thickness k of the q-axis filling groove 42 where the cut edge 45 is located satisfies 0.3*k≤k31≤0.7*k, and the angle between the cut edge 45 and the radial side edge of the q-axis filling groove 42 where the cut edge 45 is located is α, 120°≤α≤160°.

[0068] Setting the condition of 0.3*k≤k31≤0.7*k means that the thickness of the trim is controlled between 30% and 70% of the thickness of the filling slot. This design takes into account the balance of two aspects: on the one hand, the trim cannot be too narrow, otherwise it cannot effectively change the shape of the filling slot and has limited effect on improving the magnetic field distribution; on the other hand, the trim cannot be too wide, otherwise it will excessively reduce the magnetic conductivity area of ​​the filling slot, which may affect the starting ability and reluctance torque of the motor. The appropriate proportion of trim thickness helps to adjust the magnetic permeability of the filling slot, optimize the magnetic field distribution, and thus reduce torque pulsation.

[0069] The angle range of 120°≤α≤160° is set to ensure that the cut edge forms an obtuse angle with the edge of the q-axis filling slot, which can avoid sharp transitions of the magnetic field and reduce magnetic field distortion. The obtuse angle design helps to smooth the magnetic field distribution and reduce the sudden change of local magnetic field strength, thereby reducing the torque pulsation caused by the uneven magnetic field.

[0070] In this embodiment, the thickness k of the q-axis filling groove 42 where the cutting edge 45 is located varies according to the different q-axis filling grooves 42. When the q-axis filling groove 42 is a connecting filling groove 43, k takes the value k3, 0.3*k3≤k31≤0.7*k3. When the q-axis filling groove 42 is an independent filling groove 44, assuming that the number of independent filling grooves 44 on one side of the d-axis is one, the thickness of the independent filling groove 44 is k2, 0.3*k2≤k31≤0.7*k2.

[0071] In one embodiment, in a cross section perpendicular to the central axis of the rotor core 2, along the d-axis direction, the distance between the radially innermost permanent magnet slot 5 and the center of the rotor core 2 is H1, the distance between the radially innermost permanent magnet slot 5 and the radially outermost permanent magnet slot 5 is H2, and the distance between the radially outermost permanent magnet slot 5 and the d-axis filling slot 41 is H3, and H3<H2

[0072] In one embodiment, 1.5*H2≤H1≤2.5*H2, 1.5*H3≤H2≤2.5*H3.

[0073] ​The values ​​of H1, H2, and H3 gradually increase, which means that from the center to the periphery of the rotor, the space of the rotor can be fully utilized to avoid excessive compression of the permanent magnet near the center, which will lead to a decrease in the performance of the permanent magnet. At the same time, more filling slots and squirrel cage structures are arranged on the periphery of the rotor to enhance the starting ability and anti-demagnetization ability of the motor. Reluctance torque is an important characteristic of synchronous reluctance motors. It comes from the torque generated by the difference in reluctance between the dq axes when the rotor rotates. By increasing the size difference between H1, H2, and H3, the difference in reluctance between the dq axes can be increased, thereby increasing the reluctance torque, so that the motor has a stronger output capacity during synchronous operation.

[0074] The configuration of H1, H2, and H3 also affects the magnetic circuit design of the motor. Reasonable magnetic circuit design can reduce the loss on the magnetic flux path and improve the utilization rate of the magnetic flux. Furthermore, setting 0.82*R≤H1+H2+H3≤0.92*R ensures that the permanent magnet slots 5 and the filling slots 4 are generally arranged in the appropriate position of the rotor, avoids the magnetic circuit design being too narrow or too wide, reduces magnetic saturation and leakage, and thus improves the overall efficiency of the motor.

[0075] In one embodiment, 0.82*R≤H1+H2+H3≤0.92*R, where R is the outer radius of the rotor core 2. More precise control of the dimensional relationship can further improve the reluctance torque of the motor while maintaining a good magnetic flux distribution.

[0076] In one embodiment, in a cross section perpendicular to the central axis of the rotor core 2, along the d-axis direction, the distance between the radially innermost permanent magnet slot 5 and the radially outermost permanent magnet slot 5 is H2, the distance between the radially innermost connecting filling slot 43 and the radially outermost connecting filling slot 43 is k6, and 0.8*k6≤H2≤1.2*k6.

[0077] In this embodiment, since the connection filling groove 43 has two layers, k6 = k1.

[0078] The area between the permanent magnet slots 5 is the q-axis magnetic channel, and the appropriate thickness avoids oversaturation, which affects the q-axis magnetic field and inductance of the motor, thereby affecting the reluctance torque. The interval thickness H2 between the permanent magnet slots 5 is the magnetic channel of the q-axis of the motor, which is directly related to the reluctance characteristics of the motor. By setting the relationship between H2 and k4, it can be ensured that the thickness of the q-axis magnetic channel is moderate, avoiding oversaturation of the magnetic circuit caused by the channel being too wide, or the inability of the magnetic flux to flow effectively due to being too narrow. Moderate H2 can ensure that the motor has good reluctance torque during operation, thereby improving the output and efficiency of the motor.

[0079] In one embodiment, in a cross section perpendicular to the central axis of the rotor core 2, along the d-axis direction, the length of the permanent magnet 6 located radially innermost is s1, and the thickness is d1, and the length of the permanent magnet 6 located radially outermost is s2, and the thickness is d2, s1>s2, d2≥d1.

[0080] The motor torque is mainly composed of two parts: permanent magnet torque and reluctance torque. In the permanent magnet slot design, the inner permanent magnet length s1 is greater than the outer permanent magnet length s2, which means that the inner permanent magnet has a larger area and can therefore provide more magnetic flux. One part is connected in series with the outer permanent magnet, and the other part passes through the q-axis magnetic channel to increase the q-axis magnetic flux. At the same time, this unequal width design will also affect the torque characteristics of the motor. The outer permanent magnet slot is narrower, and the corresponding outer circle area is also smaller. Narrower permanent magnets can provide permanent magnet utilization.

[0081] The thickness d2 of the outer permanent magnet is set to be greater than or equal to the thickness d1 of the inner permanent magnet. This design can enhance the anti-demagnetization ability of the permanent magnet. The thickness of the permanent magnet is directly related to the anti-demagnetization ability. The greater the thickness, the stronger the anti-demagnetization ability. During the operation of the motor, especially in the startup phase and overload conditions, the permanent magnet is easily affected by the external magnetic field and demagnetized. By increasing the thickness of the outer permanent magnet, the influence of these external magnetic fields can be effectively resisted, and the risk of permanent magnet demagnetization can be reduced, thereby ensuring that the motor can operate stably under various conditions.

[0082] In one embodiment, there are multiple d-axis filling slots 41. In a cross section perpendicular to the central axis of the rotor core 2, the maximum radial width of the multiple d-axis filling slots 41 is d3, the distance between adjacent d-axis filling slots 41 is d4, and the maximum spacing between the two outermost d-axis filling slots 41 in the circumferential direction is s3, 1.5*d2<d3<3*d2, d2<d4<2*d2, s3>s2.

[0083] The thickness of d3 is set between 1.5d2 and 3d2, which can effectively improve the mechanical strength of the rotor and form a magnetic barrier near the permanent magnet, which helps to prevent the magnetic field from directly passing through the permanent magnet when the motor is running, thereby reducing the risk of demagnetization of the permanent magnet. At the same time, the appropriate thickness of d3 can ensure the formation of the squirrel cage structure and improve the self-starting ability of the motor through the asynchronous torque of the squirrel cage.

[0084] The range of d4 is set between 1d2 and 2d2, ensuring that the distribution between the filling slots is neither too dense to cause material waste and reduced mechanical strength, nor too sparse to weaken the squirrel cage effect. Reasonable setting of d4 can form an effective magnetic path, avoid magnetic circuit saturation, and optimize the starting characteristics of the motor.

[0085] s3 is set to be greater than the thickness s2 of the permanent magnet. Such a length setting can ensure that the filling slots are sufficiently distributed in the circumferential direction of the rotor, which not only increases the area of ​​the conductive material and improves the conductivity of the squirrel cage during the starting phase, thereby enhancing the asynchronous starting torque, but also helps to form a more uniform magnetic barrier, thereby better protecting the permanent magnet and preventing demagnetization.

[0086] In one embodiment, a dividing rib 9 is provided between the connecting filling slot 43 and the permanent magnet slot 5 in the same layer. In a cross section perpendicular to the central axis of the rotor core 2 , the thickness of the dividing rib 9 is k4, the thickness of the connecting filling slot 43 is k3, and 0.15*k3≤k4≤0.3*k3.

[0087] Suitable dividing ribs 9 can reduce magnetic leakage and divide the filling slots 4 and the permanent magnet slots 5 at the same time.

[0088] In one embodiment, the distance between two connection filling grooves 43 located on both sides of the q-axis and adjacent to the q-axis is k5, the thickness of the connection filling groove 43 is k3, and k3≤k5≤2*k3.

[0089] Appropriate inter-pole squirrel cage slot setting can not only reduce motor torque pulsation but also improve motor efficiency.

[0090] In one embodiment, in a cross section perpendicular to the central axis of the rotor core 2, the length of the connecting filling slot along the q-axis is more than twice the thickness of the connecting filling slot, that is, s11 / k3>0.5. The q-axis filling slot extending toward the shaft hole 7 can increase the area of ​​the filling slot and improve the starting capability of the motor, and on the other hand, the asynchronous magnetic field generated can increase the anti-demagnetization capability of the permanent magnet.

[0091] In one embodiment, the ratio of the area O1 of the connecting filling groove 43 at both ends of the permanent magnet groove 5 to the area O2 of the permanent magnet groove 5 satisfies: 0.4≤O1 / O2≤1, and the ratio of the area O1 of the outer layer connecting filling groove 43 to the area O2 of the permanent magnet groove 5 is greater than the ratio of the area O1 of the inner layer connecting filling groove 43 to the area O2 of the permanent magnet groove 5.

[0092] In one embodiment, in a cross section perpendicular to the central axis of the rotor core 2 , the ratio between the length of at least part of the connected filling slots 43 along the q-axis direction and the length of the corresponding permanent magnets 6 in the same layer is greater than 0.5.

[0093] In this embodiment, for the innermost connecting filling groove 43, the length is s11, the length of the permanent magnet in the same layer is s1, s11 / s1>0.5, for the outermost connecting filling groove 43, the length is s22, the length of the permanent magnet in the same layer is s2, s22 / s2>0.5.

[0094] The area ratio of the connecting filling slots 43 at both ends of the permanent magnet slots to the permanent magnet slots 5 is designed to be between 0.4 and 1, and the outer layer is larger than the inner layer, so that when the motor is started, the squirrel cage asynchronous torque and the permanent magnet braking torque are well balanced. The squirrel cage asynchronous torque is mainly responsible for the motor starting, while the permanent magnet braking torque contributes to the stability and efficiency of the motor when running at a constant speed.

[0095] The area of ​​the connecting filling groove 43 gradually decreases from the direction away from the q-axis. This gradient design can make the squirrel cage asynchronous torque more concentrated on the rotor surface when the motor starts, thereby enhancing the torque output in the starting stage.

[0096] The ratio of the length of the partially connected filling slot 43 along the q-axis to the length of the same layer of permanent magnets perpendicular to the d-axis is set to be greater than 0.5, ensuring that the squirrel cage structure can effectively generate asynchronous torque while the permanent magnets provide braking torque, thereby improving the starting ability and synchronous operation ability of the motor.

[0097] In one embodiment, under one pole, the ratio of the total area of ​​the permanent magnets 6 to the total area of ​​the corresponding permanent magnet slots 5 is c, and 0.4≤c≤0.7.

[0098] In one embodiment, in a cross section perpendicular to the central axis of the rotor core 2 , a ratio of the length to the thickness of the permanent magnet 6 is less than 0.15.

[0099] In one embodiment, the ratio of the length to the thickness of the permanent magnet 6 is in the range of [0.04, 0.14].

[0100] For the two-layer magnetic barrier structure, the permanent magnet 6 includes a first permanent magnet 61 and a second permanent magnet 62, wherein the length of the first permanent magnet 61 is s1 and the thickness is d1, and the length of the second permanent magnet 62 is s2 and the thickness is d2.

[0101] In one embodiment, along the d-axis direction, the radially innermost permanent magnet 6 has a length s1 and a thickness d1, and the radially outermost permanent magnet 6 has a length s2 and a thickness d2, and d1 / s1<d2 / s2.

[0102] The ratio c of the permanent magnet area to the corresponding permanent magnet slot area is in the range of 0.4 to 0.7, which ensures a good match between the permanent magnet 6 and the permanent magnet slot 5. The area ratio of the permanent magnet 6 in the slot is moderate, which helps to optimize the magnetic circuit design of the motor, improve the magnetic flux utilization of the permanent magnet, reduce the amount of permanent magnets, and thus improve the reluctance torque and overall efficiency of the motor.

[0103] The thickness to length ratios of the permanent magnets d1 / s1 and d2 / s2 are controlled at 0.04 to 0.14, respectively, and d1 / s1 is smaller than d2 / s2. A smaller thickness to length ratio of the permanent magnet means that the permanent magnet has a larger flux area, increasing the motor output torque. The smaller ratio of the inner layer and the larger flux can increase both the permanent magnet torque and the reluctance torque.

[0104] In one embodiment, the number of layers of the permanent magnet slots 5 and the permanent magnets 6 is two, the permanent magnets 6 are made of rare earth permanent magnet material, and the permanent magnet slots 5 , the permanent magnets 6 and the filling slots 4 are arranged symmetrically with respect to the d axis.

[0105] In this embodiment, the number of layers of permanent magnet slots 5 and permanent magnets 6 is 2, the permanent magnet 5 is made of rare earth permanent magnet material, and the filling slots 4, permanent magnet slots 5 and permanent magnet 6 are symmetrically arranged relative to the d-axis or q-axis; the multiple layers of permanent magnet slots 5 and the corresponding connecting filling slots 43 form a magnetic barrier, so that the q-axis and d-axis magnetic fields of the rotor structure are asymmetric, generating a magnetic resistance torque and increasing the motor output.

[0106] By adopting a double-layer permanent magnet design, the reluctance torque of the motor and the torque generated by the permanent magnet can be further improved.

[0107] In one embodiment, the filling slots 4 are filled with conductive non-magnetic material, and short-circuit end rings 8 are respectively provided at both ends of the rotor core 2. The short-circuit end rings 8 cover all the filling slots 4, short-circuit the filling slots 4, and form a squirrel cage structure.

[0108] The conductive but non-magnetic materials include aluminum, aluminum alloy, copper, copper alloy and the like.

[0109] The squirrel cage structure can generate asynchronous torque and realize self-starting of the motor.

[0110] In one embodiment, there are multiple d-axis filling slots 41, and in a cross section perpendicular to the central axis of the rotor core 2, the radial maximum width of the multiple d-axis filling slots 41 is d3, the outer periphery of the short-circuit end ring 8 is an arc structure, and the inner periphery is a polygonal structure composed of straight lines and arcs, the radial width of the short-circuit end ring 8 on the d-axis is dd1, and the radial width of the short-circuit end ring 8 on the q-axis is dq2, and dd1≥1.5*d3.

[0111] This design ensures that the short-circuit end ring can effectively contact each filling groove, reduce the waste of short-circuit end ring material, and achieve better starting ability.

[0112] The radial width dd1 of the short-circuit end ring 8 in the d-axis and the radial width dq2 in the q-axis ensure the conductivity of the squirrel cage structure while satisfying the magnetic resistance constraint. dd1≥1.5*d3 means that the width of the short-circuit end ring 8 in the d-axis direction is at least 1.5 times the maximum radial width d3 of the d-axis filling slot, which ensures sufficient conductive area to reduce resistance, thereby generating greater asynchronous torque at the starting moment.

[0113] In one embodiment, dq2 ≥ dd1.

[0114] In one embodiment, 1.5*dd1≤dq2≤2*dd1.

[0115] By further refining the width requirement of the short-circuit end ring 8 in the q-axis direction, the width of dq2 needs to be not only greater than dd1, but also controlled between 1.5 and 2 times of dd1. This helps to optimize the current path during motor starting while ensuring the strength and stability of the squirrel cage structure, reduce local concentration of current, and improve the uniform distribution of current, thereby enhancing the starting torque.

[0116] By reasonably setting the radial width of the end ring, it can be ensured that the squirrel cage structure can work effectively when the motor starts, generate sufficient asynchronous torque, enable the motor to start smoothly from a stationary state and reach a synchronous state, shorten the starting time, and enhance the motor's starting ability and anti-demagnetization ability.

[0117] Through the above design, the rotor structure provided by the present application can significantly improve the reluctance torque of the motor, reduce the cogging torque, and improve the overall efficiency and operating performance of the motor. At the same time, by filling the filling slot with conductive non-magnetic material and setting a short-circuit end ring to form a squirrel cage structure, additional torque can be provided during motor startup and low-speed operation, thereby enhancing the motor's starting ability and low-speed operation stability. This rotor structure is not only suitable for traditional application fields such as electric vehicles, industrial motors, and household appliances, but can also meet the special needs of emerging fields such as drones, precision instruments, and medical equipment, and has broad application prospects and practical benefits. In practical applications, this rotor structure can significantly improve the energy efficiency ratio of the motor, reduce energy consumption, reduce noise and vibration, and improve the stability and reliability of the equipment.

[0118] According to an embodiment of the present invention, the motor includes a stator structure and a rotor structure 1 . The rotor structure 1 is the above-mentioned rotor structure. The stator structure is sleeved on the outer peripheral side of the rotor structure 1 .

[0119] Figure 5 The comparison of the starting speeds of the technology of the present invention and the prior art shows that after adopting the structure of the present invention, the starting capability of the motor is enhanced and the starting time is significantly shortened. Figure 6The working point of the permanent magnet during the starting process of the technology of the present invention is compared with that of the prior art. By adopting the structure of the present invention and using the filling groove to protect the permanent magnet, the minimum working point of the permanent magnet is significantly improved during the starting process of the motor under harsh working conditions, and the anti-demagnetization ability is enhanced. Figure 7 For the efficiency comparison between the technology of the present invention and the prior art, at the same cost, the rotor structure of the present invention can effectively improve the motor efficiency under various load torques.

[0120] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0121] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0122] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A rotor structure, characterized in that: The invention comprises a rotor core (2), wherein a filling slot (4) and a permanent magnet slot (5) are provided on the rotor core (2), a permanent magnet (6) is installed in the permanent magnet slot (5), the filling slots (4) are distributed on the outer periphery of the rotor core (2), the filling slots (4) comprise a q-axis filling slot (42) and a d-axis filling slot (41), the q-axis filling slot (42) comprises a connecting filling slot (43) and an independent filling slot (44), the connecting filling slot (43) and the permanent magnet slot (5) are arranged in the same layer and are arranged at both ends of the permanent magnet slot (5), the independent filling slot (44) is located between adjacent connecting filling slots (43), and the spacing between the independent filling slot (44) and the connecting filling slots (43) on both sides are unequal.

2. The rotor structure according to claim 1, characterized in that: Under the same pole, the number of the permanent magnet slots (5) is the same as the number of the permanent magnets (6), the number of the permanent magnet slots (5) is N, the number of the filling slots (4) is M, and 3*N<M<6*N.

3. The rotor structure according to claim 2, characterized in that: At the same pole, the number of the q-axis filling grooves (42) is M1, 3*N≤M1≤5*N, and the number of the d-axis filling grooves (41) is M2, N≤M2≤3*N.

4. The rotor structure according to claim 1, characterized in that: Along the circumferential direction of the rotor core (2), the thickness between two adjacent connecting filling grooves (43) is k1, the total thickness of the independent filling grooves (44) located on one side of the d-axis is k2, 0.15*k1≤k2≤0.5*k1, and the thickness of the connecting filling groove (43) is k3, k2≤k3.

5. The rotor structure according to claim 1, characterized in that: In a cross section perpendicular to the central axis of the rotor core (2), the distance between the extension line of the side of the q-axis filling slot (42) close to the d-axis and the center of the rotor core (2) is L, 0.65*R≤L≤0.85*R, where R is the outer radius of the rotor core (2).

6. The rotor structure according to claim 5, characterized in that: 0.7*R≤L≤0.8*R.

7. The rotor structure according to claim 5, characterized in that: The distances between the extension lines of the sides of each q-axis filling groove (42) close to the d-axis and the center of the rotor core (2) are equal.

8. The rotor structure according to claim 5, characterized in that: The distance between the extension line of the side of the connecting filling groove (43) close to the d-axis and the center of the rotor core (2) is L1, and the distance between the extension line of the side of the independent filling groove (44) close to the d-axis and the center of the rotor core (2) is L2, and L1≤L2.

9. The rotor structure according to claim 1, characterized in that: The q-axis filling groove (42) has a cut edge (45) on one side close to the outer circle of the rotor, the thickness of the cut edge (45) along the circumferential direction is k31, the relationship between the thickness k31 of the cut edge (45) and the thickness k3 of the q-axis filling groove (42) where the cut edge (45) is located satisfies 0.3*k≤k31≤0.7*k, and the angle between the cut edge (45) and the radial side of the q-axis filling groove (42) where the cut edge (45) is located is α, and 120°≤α≤160°.

10. The rotor structure according to claim 1, characterized in that: In a cross section perpendicular to the central axis of the rotor core (2), along the d-axis direction, the distance between the permanent magnet slot (5) located at the radial innermost side and the center of the rotor core (2) is H1, the distance between the permanent magnet slot (5) located at the radial innermost side and the permanent magnet slot (5) located at the radial outermost side is H2, and the distance between the permanent magnet slot (5) located at the radial outermost side and the d-axis filling slot (41) is H3, and H3<H2<H1.

11. The rotor structure according to claim 10, characterized in that: 1.5*H2≤H1≤2.5*H2, 1.5*H3≤H2≤2.5*H3.

12. The rotor structure according to claim 11, characterized in that: 0.82*R≤H1+H2+H3≤0.92*R, wherein R is the outer radius of the rotor core (2).

13. The rotor structure according to claim 1, characterized in that: In a cross section perpendicular to the central axis of the rotor core (2), along the d-axis direction, the distance between the permanent magnet slot (5) located radially innermost and the permanent magnet slot (5) located radially outermost is H2, and the distance between the connecting filling slot (43) located radially innermost and the connecting filling slot (43) located radially outermost is k6, and 0.8*k6≤H2≤1.2*k6.

14. The rotor structure according to claim 1, characterized in that: In a cross section perpendicular to the central axis of the rotor core (2), along the d-axis direction, the permanent magnet (6) located radially innermost has a length s1 and a thickness d1, and the permanent magnet (6) located radially outermost has a length s2 and a thickness d2, s1>s2, d2≥d1.

15. The rotor structure according to claim 1, characterized in that: There are a plurality of d-axis filling slots (41), and in a cross section perpendicular to the central axis of the rotor core (2), the maximum radial width of the plurality of d-axis filling slots (41) is d3, the distance between adjacent d-axis filling slots (41) is d4, the maximum spacing between the two outermost d-axis filling slots (41) in the circumferential direction is s3, 1.5*d2<d3<3*d2, d2<d4<2*d2, s3>s2.

16. The rotor structure according to claim 1, characterized in that: A dividing rib (9) is provided between the connecting filling slot (43) and the permanent magnet slot (5) on the same layer. In a cross section perpendicular to the central axis of the rotor core (2), the thickness of the dividing rib (9) is k4, the thickness of the connecting filling slot (43) is k3, and 0.15*k3≤k4≤0.3*k3.

17. The rotor structure according to claim 1, characterized in that: The distance between two connecting filling grooves (43) located on both sides of the q-axis and adjacent to the q-axis is k5, and the thickness of the connecting filling grooves (43) is k3, where k3≤k5≤2*k3.

18. The rotor structure according to claim 1, characterized in that: In a cross section perpendicular to the central axis of the rotor core (2), the ratio between the length of at least part of the connecting filling slots (43) along the q-axis direction and the length of the corresponding permanent magnets (6) in the same layer is greater than 0.

5.

19. The rotor structure according to claim 1, characterized in that: In a cross section perpendicular to the central axis of the rotor core (2), the ratio of the length to the thickness of the permanent magnet (6) is less than 0.

15.

20. The rotor structure according to claim 19, characterized in that The ratio of the length to the thickness of the permanent magnet (6) is in the range of [0.04, 0.14].

21. The rotor structure according to claim 19, characterized in that Along the d-axis direction, the permanent magnet (6) located radially innermost has a length s1 and a thickness d1, and the permanent magnet (6) located radially outermost has a length s2 and a thickness d2, and d1 / s1<d2 / s2.

22. The rotor structure according to claim 1, characterized in that The number of layers of the permanent magnet slots (5) and the permanent magnets (6) is two, the permanent magnets (6) are made of rare earth permanent magnet material, and the permanent magnet slots (5), the permanent magnets (6) and the filling slots (4) are symmetrically arranged relative to the d-axis.

23. The rotor structure according to claim 1, characterized in that The filling slots (4) are filled with conductive but non-magnetic material, and short-circuit end rings (8) are respectively provided at both ends of the rotor core (2). The short-circuit end rings (8) cover all the filling slots (4), short-circuit the filling slots (4) and form a squirrel cage structure.

24. The rotor structure according to claim 23, characterized in that: There are a plurality of d-axis filling grooves (41), and in a cross section perpendicular to the central axis of the rotor core (2), the maximum radial width of the plurality of d-axis filling grooves (41) is d3. The outer circumference of the short-circuit end ring (8) is an arc structure, and the inner circumference is a polygonal structure composed of straight lines and arcs. The radial width of the short-circuit end ring (8) on the d-axis is dd1, and the radial width of the short-circuit end ring (8) on the q-axis is dq2, and dd1≥1.5*d3.

25. The rotor structure according to claim 24, characterized in that dq2≥dd1.

26. The rotor structure according to claim 25, characterized in that 1.5*dd1≤dq2≤2*dd1.

27. An electric motor, comprising a stator structure and a rotor structure (1), characterized in that: The rotor structure (1) is the rotor structure according to any one of claims 1 to 26, and the stator structure is sleeved on the outer peripheral side of the rotor structure (1).

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