electric machine

Abstract

The application provides a motor, and relates to the technical field of motors.The motor comprises a rotor core, a first magnet embedded in the rotor core, N first magnets, N is an integer greater than 1, the N first magnets are distributed at intervals in the circumferential direction of the rotor core, and a second magnet embedded in the rotor core, the second magnet is located between two adjacent first magnets in the circumferential direction of the rotor core; wherein the rotor core is cut by a plane perpendicular to the axis of the rotor core to obtain a cross section; in the cross section, the first magnet extends in the circumferential direction of the rotor core, and the second magnet extends in the radial direction of the rotor core.

Description

Technical Field

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

[0002] In related technologies, permanent magnet motors utilize permanent magnet torque and reluctance torque to synthesize output torque in order to generate high torque over a wide speed range.

[0003] Permanent magnet torque is generated by the orthogonal interaction between the magnet and the armature current. The magnet, placed in the rotor core, produces reluctance torque. However, utilizing reluctance torque increases the angle between the motor current and the induced electromotive force, increasing the current amplitude and angle for the same output torque, thus reducing the magnet's utilization rate. This results in a low power factor in the motor.

[0004] Therefore, overcoming the aforementioned technical deficiencies has become an urgent technical problem to be solved. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art.

[0006] Therefore, the present invention proposes an electric motor.

[0007] In view of the above, a first aspect of the present invention provides an electric motor, the electric motor comprising: a rotor core; a first magnet, embedded in the rotor core, wherein there are N first magnets, the N first magnets being distributed at intervals along the circumferential direction of the rotor core, and N being an integer greater than 1; a second magnet, embedded in the rotor core, wherein the second magnet is located between two adjacent first magnets in the circumferential direction of the rotor core; wherein the rotor core is cut by a plane perpendicular to the axis of the rotor core to obtain a cross section; in the cross section, the first magnet extends in the circumferential direction of the rotor core, and the second magnet extends in the radial direction of the rotor core.

[0008] This application discloses an electric motor comprising a rotor core, a first magnet, and a second magnet. The rotor is made of metal, and the rotor core is cylindrical. The first and second magnets are made of permanent magnet material and are embedded inside the rotor core to form a rotor assembly.

[0009] Based on this, the number of first magnets is N, where N is an integer greater than 1. The rotor core, the first magnets, and the second magnets are cut through a plane perpendicular to the rotor core's axis. In the resulting cross-section, the rotor core is circular, and the N first magnets are located inside the rotor core and spaced apart along its circumference. Specifically, the N first magnets can be evenly distributed on a circle centered on the rotor core. A gap is left between any two adjacent first magnets along the circumference of the rotor core. The first magnets are arranged between any two adjacent first magnets along the circumference of the rotor core, and a second magnet is placed between any two adjacent first magnets.

[0010] The first magnet extends circumferentially along the rotor core in the cross-section, and the second magnet extends along an arc sharing a center with the rotor core within the rotor. The second magnet extends radially along the rotor core in the cross-section, meaning it extends along a straight line that coincides with or is parallel to a certain diameter of the rotor core within the rotor. The directions of extension of the first and second magnets refer to their physical orientation in the cross-section and are unrelated to the shape of the outlines formed by the first and second magnets.

[0011] As can be seen, the stator proposed in this application is embedded with a tile-shaped first magnet with a convex surface facing the outer wall of the rotor core and a concave surface facing the axis of the rotor core, and strip-shaped second magnets extending radially along the rotor core are interspersed among the multiple first magnets.

[0012] In related technologies, to improve the reluctance torque of permanent magnet motors, the circumferential permanent magnets inside the rotor core are often bent towards the outer circumference of the rotor core. However, in this approach, the proportion of permanent magnet torque is relatively small, while the proportion of reluctance torque involving current and voltage is relatively large. As a result, the orthogonality between magnetic flux and torque deteriorates with the increase of the axial inductance within the permanent magnet, leading to a decrease in the motor's power factor. To address this, this application combines the aforementioned first and second magnets to increase the flux linkage per unit area. This increases the proportion of permanent magnet torque in the motor's output torque, reducing the current-voltage angle and thus improving the motor's power factor, thereby solving the technical problems existing in the aforementioned related technologies. This ultimately optimizes the permanent magnet structure layout within the motor, improves the motor's power factor, and enhances the motor's operating efficiency.

[0013] Specifically, the rotor core is made of silicon steel, and the first and second magnets are formed by rare earth sintered magnets, rare earth bonded magnets, ferrite sintered magnets or ferrite bonded magnets.

[0014] In addition, the motor provided by the present invention may also have the following additional technical features:

[0015] In the above technical solution, two second magnets form a group, and the motor includes N groups of second magnets, with two second magnets in the same group arranged side by side; in the circumferential direction of the rotor core, N second magnets and N groups of first magnets are alternately arranged.

[0016] In this technical solution, a set of second magnets is arranged between two circumferentially adjacent first magnets, that is, N second magnets and N sets of first magnets are alternately distributed along the circumferential direction inside the rotor core. Among them, each set of first magnets includes two first magnets, and the two strip-shaped first magnets extend along a straight line parallel to the radial direction of the rotor core, and the two first magnets in the same set are arranged side by side.

[0017] In this structure, a corresponding second magnet is provided at both ends of the tile-shaped first magnet. This structural layout is conducive to increasing the magnetic flux per unit area, which can further enhance the proportion of permanent magnet torque in the motor output torque, thereby achieving the technical effects of optimizing the permanent magnet structure layout inside the motor, improving the motor power factor, and improving the motor working efficiency.

[0018] In any of the above technical solutions, the rotor core includes multiple silicon steel sheets stacked together; the rotor core also includes a shaft hole, which shares an axis with the rotor core, the diameter of the shaft hole is a first diameter, and the diameter of the rotor core is a second diameter; the rotor core also includes N first mounting holes and 2N second mounting holes, the first mounting holes and the second mounting holes are located around the shaft hole, N first magnets are correspondingly disposed in the N first mounting holes, and 2N second magnets are correspondingly disposed in the 2N second mounting holes.

[0019] In this technical solution, the rotor core is composed of multiple silicon steel sheets, which are stacked together to form a columnar rotor core. A shaft hole is machined in the central region of the rotor to mount a rotating shaft, which then outputs power to the outside of the motor. N first mounting holes are machined circumferentially within the rotor core, surrounding the through-hole. The shapes of the first mounting holes are adapted to the shapes of the first magnets, and the N first magnets are inserted one-to-one into each of the N first mounting holes. Correspondingly, 2N second mounting holes are machined radially within the rotor core, surrounding the through-hole. The shapes of the second mounting holes are adapted to the shapes of the second magnets, and the 2N second magnets are inserted one-to-one into each of the 2N second mounting holes to form N magnetic poles.

[0020] By setting the first mounting hole and the second mounting hole, the first magnet and the second magnet can be accurately positioned in the rotor core, ensuring that the relative positions of the first magnet and the second magnet on the rotor core are accurate, reducing the possibility of misalignment or even detachment of the first magnet and the second magnet, thereby achieving the technical effects of improving the stability of the motor structure, improving the reliability of the motor, and reducing the motor failure rate.

[0021] Specifically, each silicon steel sheet has a circular groove in its central area, and arc-shaped grooves and strip-shaped grooves are machined around the circular groove. During assembly, multiple silicon steel sheets are stacked together, and the circular grooves, arc-shaped grooves and strip-shaped grooves on the multiple silicon steel sheets are aligned. Multiple circular grooves are combined to form a through hole, multiple arc-shaped grooves are combined to form a first mounting hole, and multiple strip-shaped grooves are combined to form a second mounting hole.

[0022] In any of the above technical solutions, the distance between the first mounting hole and the adjacent second mounting hole is the first spacing; the width of the adjacent second mounting hole is the first width; and the first spacing is less than the first width.

[0023] In this technical solution, two second mounting holes are respectively provided at both ends of the arc-shaped first mounting hole. The minimum distance between the first mounting hole and the second mounting hole adjacent to it is the first spacing W3, and the width of the second mounting hole adjacent to the first mounting hole is the first width W2. Based on this, the first spacing is less than the first width.

[0024] By controlling the first gap to be smaller than the first width, the saturation magnetic flux density of the rotor core can be designed to be approximately 2.0T. This improves the utilization rate of the rotor core, increases the number of magnetic lines passing through a unit area, and thus meets the high-efficiency design requirements of the motor, achieving the technical effect of improving the motor power factor.

[0025] Specifically, when selecting ferrite permanent magnets as the first and second magnets, the magnetic flux density of the first and second magnets is lower than that of rare earth materials. The structural layout of this technical solution is conducive to improving the utilization rate of the stator core, so as to avoid problems such as oversaturation, magnetic flux deformation and pulsation in the motor.

[0026] In any of the above technical solutions, the distance between the first mounting hole and the shaft hole in the radial direction of the rotor core is the second spacing; the second spacing, the first diameter and the second diameter satisfy the following relationship: RO2≥(D2-D1)÷3; where RO2 is the second spacing, D2 is the second diameter and D1 is the first diameter.

[0027] In this technical solution, the distance between the first mounting hole and the shaft hole in the radial direction of the rotor core is the second spacing RO2, the outer diameter of the rotor core is the second diameter D2, and the inner diameter of the rotor core, i.e., the diameter of the through hole, is the first diameter D1. Based on this, RO2, D1, and D2 satisfy the following relationship: RO2 ≥ (D2 - D1) ÷ 3.

[0028] By limiting the above dimensional relationships, the leakage flux of the motor can be precisely controlled to enhance the motor's output under high-frequency overload, thereby reducing the motor's torque pulsation, enhancing the motor's anti-demagnetization ability, and ultimately achieving the technical effects of improving motor safety and reliability and reducing motor failure rate.

[0029] In any of the above technical solutions, in the radial direction of the rotor core, the distance between the first mounting hole and the outer wall of the rotor core is the third spacing, and the distance between the second mounting hole and the outer wall of the rotor core is the fourth spacing L1; the third spacing is greater than or equal to twice the fourth spacing; the fourth spacing is greater than the thickness of the silicon steel sheet.

[0030] In this technical solution, the distance between the first mounting hole and the outer wall surface of the rotor core in the radial direction is the third spacing L2. The multiple silicon steel sheets that make up the rotor core have the same thickness, and the thickness of each silicon steel sheet is T. Based on this, L1 and T satisfy the following relationship: L1 > T.

[0031] In any of the above technical solutions, the rotor core further includes N through holes, which connect two second mounting holes adjacent to the first mounting hole; the through holes are located between the second mounting holes and the shaft hole.

[0032] In this technical solution, the rotor core also has N through holes. These through holes are located between two second mounting holes on either side of the arc-shaped first mounting hole. The left and right ends of the through holes connect to the two second mounting holes on either side of the first mounting hole. In the radial direction of the rotor core, the through holes are located between the second mounting holes and the shaft hole. That is, the two second mounting holes and one through hole combine to form a U-shaped groove. The opening side of this U-shaped groove faces the circumferential side of the stator core, and the first mounting hole is located within the opening of the U-shaped groove. In this U-shaped groove, the second mounting hole area is used to fill with a second magnet, while the through hole area can be filled with a magnetic material, such as a hyperbolic permanent magnet. However, in this technical solution, the through hole area is not filled with magnetic material, and two rectangular second magnets are inserted into the U-shaped groove to fill the two second mounting holes.

[0033] By incorporating through-holes, motor performance can be improved through optimization of the magnetic pole shape. Furthermore, by limiting the second magnet to avoid the through-holes, an air barrier can be created. This reduces the amount of permanent magnet material needed while still meeting electrode design requirements, thus lowering motor production costs. It also reduces the manufacturing complexity of the second magnet and rotor core. Additionally, the perforated through-holes allow for gas and liquid flow, improving the motor's gas-liquid fluidity.

[0034] In any of the above technical solutions, the distance between the through hole and the shaft hole in the radial direction of the rotor core is the fifth spacing; the fifth spacing, the first diameter and the second diameter satisfy the following relationship: RO1≥(D2-D1)÷2; where RO1 is the fifth spacing, D2 is the second diameter and D1 is the first diameter.

[0035] In this technical solution, the distance between the through hole and the shaft hole in the radial direction of the rotor core is the fifth spacing RO1, the outer diameter of the rotor core is the second diameter D2, and the inner diameter of the rotor core, i.e., the diameter of the through hole, is the first diameter D1. Based on this, RO1, D1, and D2 satisfy the following relationship: RO2 ≥ (D2 - D1) ÷ 2.

[0036] By limiting the above dimensional relationships, the leakage flux of the motor can be precisely controlled to enhance the motor's output under high-frequency overload, thereby reducing the motor's torque pulsation, enhancing the motor's anti-demagnetization ability, and ultimately achieving the technical effects of improving motor safety and reliability and reducing motor failure rate.

[0037] In any of the above technical solutions, the motor further includes: a partition portion disposed within the through hole, the partition portion dividing the through hole in the tangential direction of the rotor core.

[0038] In this technical solution, a partition is provided within the through hole, specifically a horizontal partition located in the middle of the through hole, dividing it into left and right parts. The left through hole connects to the second mounting hole adjacent to the left side of the corresponding first mounting hole, and the right through hole connects to the second mounting hole adjacent to the right side of the corresponding first mounting hole. By providing the partition, the leakage flux of the motor can be reduced while maintaining airflow and ensuring the smooth flow of motor components, thereby improving the motor's energy efficiency ratio and practicality.

[0039] In any of the above technical solutions, the width of the partition is the second width, which is greater than the thickness of the silicon steel sheet.

[0040] In this technical solution, the width of the partition is the second width W5, the thickness of the multiple silicon steel sheets that make up the rotor core is the same, and the thickness of each silicon steel sheet is T. Based on this, W5 and T satisfy the following relationship: W5 > T.

[0041] In any of the above technical solutions, the motor further includes: a stator core, the stator core being cylindrical, and the rotor core passing through the stator core; a plurality of stator teeth, disposed on the inner annular surface of the stator core and extending in the radial direction of the stator core; the plurality of stator teeth being spaced apart on the circumference of the rotor core, and two adjacent stator teeth enclosing a stator slot facing the rotor core.

[0042] In this technical solution, the motor also includes a stator core, which is cylindrical, and the rotor core is housed inside the cylindrical stator core. The inner annular surface of the stator core and the outer annular surface of the rotor core are spaced apart. Furthermore, multiple stator teeth extending towards the rotor core are provided on the inner annular surface of the stator core. These teeth are spaced apart circumferentially around the rotor core. Adjacent stator teeth form a U-shaped stator slot, with the slot opening facing the circumferential surface of the rotor core. The motor also includes windings wound around the circumferential surface of the stator core and in the stator slots to form a stator assembly. When the motor is energized, the stator assembly generates an electromagnetic field, which drives the rotor assembly to rotate synchronously, converting electrical energy into mechanical energy.

[0043] In any of the above technical solutions, the width of the stator slot opening is the third width; the distance between the two second mounting holes corresponding to the two second magnets in the same group is the sixth spacing; the sixth spacing is less than the third width.

[0044] In this technical solution, the width of the stator slot opening is the third width Tb1, and the distance between the two second mounting holes corresponding to the two second magnets in the same group is the sixth spacing W1, wherein Tb1 and W1 satisfy the following relationship: W1 < Tb1.

[0045] By limiting the above dimensional relationships, it is beneficial to accurately control the leakage flux of the motor and enhance the output of the motor under high-frequency overload, thereby reducing the torque pulsation of the motor and enhancing the motor's anti-demagnetization ability.

[0046] In any of the above technical solutions, the distance between the centerlines of two adjacent stator teeth is the seventh spacing; the seventh spacing is greater than the width of the second mounting hole.

[0047] In this technical solution, the distance between the centerlines of two adjacent stator teeth is the seventh distance Tb2, which is the distribution spacing of the stator teeth. The width of the second mounting hole is W2, where Tb2 and W2 satisfy the following relationship: Tb2 > W2.

[0048] By limiting the above dimensional relationships, it is beneficial to accurately control the leakage flux of the motor and enhance the output of the motor under high-frequency overload, thereby reducing the torque pulsation of the motor and enhancing the motor's anti-demagnetization ability.

[0049] In any of the above technical solutions, the surface of the first magnet facing the rotor core axis is the first surface, and the surface away from the rotor core axis is the second surface. The first surface is a concave arc surface or a plane, and the second surface is a convex arc surface.

[0050] In this technical solution, the first magnet extending along the circumferential direction of the rotor core includes a first surface and a second surface. The first surface faces the axis of the rotor core, i.e., towards the inner side of the rotor core, and the second surface faces the outer circumferential surface of the rotor core, i.e. towards the outer side of the rotor core.

[0051] Based on this, the first surface can be a flat surface, or it can be a concave curved surface, while the second surface is a convex curved surface. When a concave curved surface is chosen as the first surface, the first magnet is tile-shaped. When a flat surface is chosen as the first surface, the first magnet is bread-shaped.

[0052] The first magnet protected by this technical solution can, in conjunction with the second magnets on both sides, increase the magnetic flux density per unit area. This increases the proportion of permanent magnet torque in the motor's output torque, thereby reducing the current-voltage angle and improving the motor's power factor. Furthermore, the second magnets protected by this technical solution are easier to manufacture, which helps reduce process complexity and production costs.

[0053] In any of the above technical solutions, the second magnet is rectangular.

[0054] In this technical solution, the second magnet is rectangular, and two rectangular second magnets in the same group are arranged side by side with a gap between them. Using rectangular second magnets helps to reduce the complexity of the manufacturing process and the production cost.

[0055] Additional aspects and advantages of the invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0056] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0057] Figure 1 One of the schematic diagrams of a motor according to an embodiment of the present invention is shown;

[0058] Figure 2 A second schematic diagram of the structure of a motor according to an embodiment of the present invention is shown;

[0059] Figure 3 A third schematic diagram of the structure of a motor according to an embodiment of the present invention is shown;

[0060] Figure 4 A fourth schematic diagram of the structure of a motor according to an embodiment of the present invention is shown;

[0061] Figure 5 A diagram showing the relationship between the phase of the current and the magnetic flux of an electric motor according to an embodiment of the present invention is provided.

[0062] Figure 6 A data comparison diagram of an electric motor according to an embodiment of the present invention and an electric motor in the related art is shown.

[0063] in, Figures 1 to 4 The correspondence between the reference numerals and component names in the attached drawings is as follows:

[0064] 100 Motor, 110 Rotor Core, 1102 Shaft Hole, 1104 First Mounting Hole, 1106 Second Mounting Hole, 1108 Through Hole, 112 Divider, 120 First Magnet, 130 Second Magnet, 140 Stator Core, 142 Stator Tooth, 144 Stator Slot. Detailed Implementation

[0065] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0066] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0067] The following reference Figures 1 to 6A motor is described according to some embodiments of the present invention.

[0068] like Figure 1 and Figure 2 As shown, a first aspect embodiment of the present invention provides an electric motor 100, which includes: a rotor core 110; a first magnet 120 embedded in the rotor core 110, wherein there are N first magnets 120, which are distributed at intervals along the circumferential direction of the rotor core 110, and N is an integer greater than 1; and a second magnet 130 embedded in the rotor core 110, wherein the second magnet 130 is located between two adjacent first magnets 120 in the circumferential direction of the rotor core 110; wherein the rotor core 110 is cut by a plane perpendicular to the axis of the rotor core 110 to obtain a cross section; in the cross section, the first magnets 120 extend in the circumferential direction of the rotor core 110, and the second magnets 130 extend in the radial direction of the rotor core 110.

[0069] This application discloses an electric motor 100, which includes a rotor core 110, a first magnet 120, and a second magnet 130. The rotor is made of metal, and the rotor core 110 is columnar. The first magnet 120 and the second magnet 130 are made of permanent magnet material and are embedded inside the rotor core 110 to form a rotor assembly.

[0070] Based on this, the number of first magnets 120 is N, where N is an integer greater than 1. The rotor core 110, the first magnets 120, and the second magnets 130 are cut through a plane perpendicular to the axis of the rotor core 110. In the resulting cross-section, the rotor core 110 is circular, and the N first magnets 120 are located inside the rotor core 110 and spaced apart along the circumferential direction of the rotor core 110. Specifically, the N first magnets 120 can be evenly distributed on a circle centered on the center of the rotor core 110. A gap is left between any two adjacent first magnets 120 along the circumference of the rotor core 110. The first magnets 120 are arranged between any two adjacent first magnets 120 along the circumference of the rotor core 110, and a second magnet 130 is arranged between any two adjacent first magnets 120.

[0071] The first magnet 120 extends circumferentially along the rotor core 110 in cross-section, and extends along an arc sharing a center with the rotor core 110 within the rotor. The second magnet 130 extends radially along the rotor core 110 in cross-section, meaning it extends along a straight line within the rotor that coincides with or is parallel to a certain diameter of the rotor core 110. The extending directions of the first magnet 120 and the second magnet 130 refer to their physical orientation in cross-section and are unrelated to the shape of the outlines extracted from the first magnet 120 and the second magnet 130.

[0072] As can be seen, the stator proposed in this application is embedded with a tile-shaped first magnet with a convex surface facing the outer wall of the rotor core 110 and a concave surface facing the axis of the rotor core 110, and strip-shaped second magnets extending radially along the rotor core 110 are interspersed among the multiple first magnets.

[0073] In related technologies, to improve the reluctance torque of a permanent magnet motor, the circumferential permanent magnets inside the rotor core are often bent towards the outer circumference of the rotor core. However, in this approach, the proportion of permanent magnet torque is relatively small, while the proportion of reluctance torque involving current and voltage is relatively large. As a result, the orthogonality between magnetic flux and torque deteriorates with the increase of the axial inductance within the permanent magnet, leading to a decrease in the motor's power factor. To address this, this application combines the aforementioned first and second magnets to increase the flux linkage per unit area. This increases the proportion of permanent magnet torque in the output torque of the motor 100, reducing the current-voltage angle of the motor 100 and thus improving the power factor of the motor 100, thereby solving the technical problems existing in the aforementioned related technologies. This ultimately optimizes the permanent magnet structure layout within the motor 100, improves the power factor of the motor 100, and enhances the operating efficiency of the motor 100.

[0074] Specifically, the rotor core 110 is made of silicon steel, and the first magnet 120 and the second magnet 130 are formed by rare earth sintered magnets, rare earth bonded magnets, ferrite sintered magnets or ferrite bonded magnets.

[0075] like Figure 1 and Figure 2 As shown, in the above embodiment, two second magnets 130 form a group, and the motor 100 includes N groups of second magnets 130, with two second magnets 130 in the same group arranged side by side; in the circumferential direction of the rotor core 110, N second magnets 130 and N groups of first magnets 120 are alternately arranged.

[0076] In this embodiment, a set of second magnets 130 is disposed between two circumferentially adjacent first magnets 120, that is, N second magnets 130 and N sets of first magnets 120 are disposed alternately in the circumferential direction inside the rotor core 110. Among them, each set of first magnets 120 includes two first magnets 120, and the two strip-shaped first magnets 120 extend along a straight line parallel to the radial direction of the rotor core 110, and the two first magnets 120 in the same set are arranged side by side.

[0077] In this structure, a corresponding second magnet 130 is provided at both ends of the tile-shaped first magnet 120. This structural layout is conducive to increasing the magnetic flux per unit area, which can further enhance the proportion of permanent magnet torque in the output torque of motor 100, thereby achieving the technical effect of optimizing the permanent magnet structure layout inside motor 100, improving the power factor of motor 100, and improving the working efficiency of motor 100.

[0078] like Figure 1 and Figure 2 As shown, in any of the above embodiments, the rotor core 110 includes a plurality of silicon steel sheets stacked together; the rotor core 110 also includes a shaft hole 1102, the shaft hole 1102 and the rotor core 110 share the same axis, the diameter of the shaft hole 1102 is a first diameter, and the diameter of the rotor core 110 is a second diameter; the rotor core 110 also includes N first mounting holes 1104 and 2N second mounting holes 1106, the first mounting holes 1104 and the second mounting holes 1106 are located around the shaft hole 1102, N first magnets 120 are correspondingly disposed in the N first mounting holes 1104, and 2N second magnets 130 are correspondingly disposed in the 2N second mounting holes 1106.

[0079] In this embodiment, the rotor core 110 is composed of multiple silicon steel sheets, which are stacked together to form a columnar rotor core 110. A shaft hole 1102 is machined into the central region of the rotor core, and the shaft hole 1102 is used to mount a rotating shaft to output power to the motor 100. N first mounting holes 1104 are machined circumferentially within the rotor core 110, surrounding the through hole 1108. The shape of the first mounting holes 1104 is adapted to the shape of the first magnets 120, and the N first magnets 120 are inserted one-to-one into the N first mounting holes 1104. Correspondingly, 2N second mounting holes 1106 are machined radially inside the rotor core 110. The 2N second mounting holes 1106 surround the through hole 1108. The shape of the second mounting holes 1106 is adapted to the shape of the second magnet 130. The 2N second magnets 130 are inserted into the 2N second mounting holes 1106 one by one to form N magnetic poles.

[0080] By setting the first mounting hole 1104 and the second mounting hole 1106, the first magnet 120 and the second magnet 130 can be accurately positioned in the rotor core 110, ensuring that the relative positions of the first magnet 120 and the second magnet 130 on the rotor core 110 are accurate, reducing the possibility of misalignment or even detachment of the first magnet 120 and the second magnet 130, thereby achieving the technical effects of improving the structural stability of the motor 100, improving the reliability of the motor 100, and reducing the failure rate of the motor 100.

[0081] Specifically, each silicon steel sheet has a circular groove in its central area, and arc-shaped grooves and strip-shaped grooves are machined around the circular groove. During assembly, multiple silicon steel sheets are stacked together, and the circular grooves, arc-shaped grooves and strip-shaped grooves on the multiple silicon steel sheets are aligned. Multiple circular grooves are combined to form a through hole 1108, multiple arc-shaped grooves are combined to form a first mounting hole 1104, and multiple strip-shaped grooves are combined to form a second mounting hole 1106.

[0082] like Figure 1As shown, in any of the above embodiments, the distance between the first mounting hole 1104 and the adjacent second mounting hole 1106 is a first spacing; the width of the adjacent second mounting hole 1106 is a first width; and the first spacing is less than the first width.

[0083] In this embodiment, two second mounting holes 1106 are respectively provided at both ends of the arc-shaped first mounting hole 1104. The minimum distance between the first mounting hole 1104 and the second mounting hole 1106 adjacent to it is the first spacing W3, and the width of the second mounting hole 1106 adjacent to the first mounting hole 1104 is the first width W2. Based on this, the first spacing is less than the first width.

[0084] By controlling the first gap to be smaller than the first width, the saturation magnetic flux density of the rotor core 110 can be designed to be approximately 2.0T, thereby improving the utilization rate of the rotor core 110, increasing the number of magnetic lines passing through a unit area, and thus meeting the high-efficiency design requirements of the motor 100, achieving the technical effect of improving the power factor of the motor 100.

[0085] Specifically, when ferrite permanent magnets are selected as the first magnet 120 and the second magnet 130, the magnetic flux density of the first magnet 120 and the second magnet 130 is lower than that of rare earth materials. The structural layout of this embodiment is conducive to improving the utilization rate of the stator core 140, so as to avoid problems such as oversaturation, magnetic flux deformation and pulsation in the motor 100.

[0086] like Figure 1 As shown, in any of the above embodiments, the distance between the first mounting hole 1104 and the shaft hole 1102 in the radial direction of the rotor core 110 is the second spacing; the second spacing, the first diameter and the second diameter satisfy the following relationship: RO2≥(D2-D1)÷3; where RO2 is the second spacing, D2 is the second diameter and D1 is the first diameter.

[0087] In this embodiment, in the radial direction of the rotor core 110, the distance between the first mounting hole 1104 and the shaft hole 1102 is the second spacing RO2, the outer diameter of the rotor core 110 is the second diameter D2, and the inner diameter of the rotor core 110, i.e., the diameter of the through hole 1108, is the first diameter D1. Based on this, RO2, D1, and D2 satisfy the following relationship: RO2 ≥ (D2 - D1) ÷ 3.

[0088] By limiting the above-mentioned dimensional relationships, the leakage flux of motor 100 can be precisely controlled to enhance the output of motor 100 under high-frequency overload, thereby reducing the torque pulsation of motor 100, enhancing the anti-demagnetization capability of motor 100, and thus achieving the technical effect of improving the safety and reliability of motor 100 and reducing the failure rate of motor 100.

[0089] like Figure 1As shown, in any of the above embodiments, in the radial direction of the rotor core 110, the distance between the first mounting hole 1104 and the outer wall of the rotor core 110 is the third spacing L2, and the distance between the second mounting hole 1106 and the outer wall of the rotor core 110 is the fourth spacing L1; the third spacing is greater than or equal to twice the fourth spacing; the fourth spacing is greater than the thickness of the silicon steel sheet.

[0090] In this embodiment, in the radial direction of the rotor core 110, the distance between the first mounting hole 1104 and the outer wall surface of the rotor core 110 is the third spacing. The thickness of the plurality of silicon steel sheets constituting the rotor core 110 is consistent, and the thickness of each silicon steel sheet is T. Based on this, L1 and L2 satisfy the following relationship: L2 > 2 × L1, and L1 and T satisfy the following relationship: L1 > T.

[0091] Specifically, in the radial direction of the rotor core 110, the distance between the second mounting hole 1106 and the shaft hole 1102 is L3, where L1 and L3 satisfy the following relationship: L3≥2×L1.

[0092] like Figure 1 As shown, in any of the above embodiments, the rotor core 110 further includes N through holes 1108, the through holes 1108 connecting two second mounting holes 1106 adjacent to the first mounting hole 1104; the through holes 1108 are located between the second mounting holes 1106 and the shaft hole 1102.

[0093] In this embodiment, the rotor core 110 is further provided with N through holes 1108. The through holes 1108 are located between two second mounting holes 1106 on both sides of the arc-shaped first mounting hole 1104. The left and right ends of the through holes 1108 connect to the two second mounting holes 1106 on both sides of the first mounting hole 1104. In the radial direction of the rotor core 110, the through holes 1108 are located between the second mounting holes 1106 and the shaft hole 1102. That is, the two second mounting holes 1106 and the through hole 1108 are combined to form a U-shaped groove. The opening side of the U-shaped groove faces the peripheral side of the stator core 140. The first mounting hole 1104 is located in the groove opening of the U-shaped groove. In this U-shaped groove, the area of ​​the second mounting hole 1106 is used to fill the second magnet 130, and the area of ​​the through hole 1108 can be filled with magnetic material, for example, by filling the second mounting hole 1106 and the through hole 1108 with a hyperbolic permanent magnet. However, in this embodiment, the through hole 1108 area is not filled with magnetic material, and two rectangular second magnets 130 are inserted into the U-shaped groove to fill the two second mounting holes 1106.

[0094] By setting the through hole 1108, the performance of the motor 100 can be improved by optimizing the shape of the magnetic poles. Furthermore, by limiting the second magnet 130 to avoid the through hole 1108, an air barrier can be formed. This reduces the amount of permanent magnet material used while meeting electrode design requirements, thus lowering the production cost of the motor 100. It also reduces the manufacturing complexity of the second magnet 130 and the rotor core 110. Additionally, the hollowed-out through hole 1108 allows for gas and liquid flow, improving the gas-liquid flowability of the motor 100.

[0095] like Figure 1 As shown, in any of the above embodiments, the distance between the through hole 1108 and the shaft hole 1102 in the radial direction of the rotor core 110 is the fifth spacing; the fifth spacing, the first diameter and the second diameter satisfy the following relationship: RO1≥(D2-D1)÷2; where RO1 is the fifth spacing, D2 is the second diameter and D1 is the first diameter.

[0096] In this embodiment, in the radial direction of the rotor core 110, the distance between the through hole 1108 and the shaft hole 1102 is the fifth spacing RO1, the outer diameter of the rotor core 110 is the second diameter D2, and the inner diameter of the rotor core 110, i.e., the diameter of the through hole 1108, is the first diameter D1. Based on this, RO1, D1, and D2 satisfy the following relationship: RO2 ≥ (D2 - D1) ÷ 2.

[0097] By limiting the above-mentioned dimensional relationships, the leakage flux of motor 100 can be precisely controlled to enhance the output of motor 100 under high-frequency overload, thereby reducing the torque pulsation of motor 100, enhancing the anti-demagnetization capability of motor 100, and thus achieving the technical effect of improving the safety and reliability of motor 100 and reducing the failure rate of motor 100.

[0098] like Figure 3 As shown, in any of the above embodiments, the motor 100 further includes a partition 112 disposed in the through hole 1108, the partition 112 partitioning the through hole 1108 in the tangential direction of the rotor core 110.

[0099] In this embodiment, a partition 112 is provided within the through hole 1108. Specifically, the partition 112 is horizontally disposed in the middle of the through hole 1108 to divide the through hole 1108 into left and right parts. The left through hole 1108 communicates with the second mounting hole 1106 adjacent to the left side of the corresponding first mounting hole 1104, and the right through hole 1108 communicates with the second mounting hole 1106 adjacent to the right side of the corresponding first mounting hole 1104. By providing the partition 112, the leakage flux of the motor 100 can be reduced while forming an air barrier and ensuring the flow of energy within the motor 100, thereby achieving the technical effect of improving the energy efficiency ratio and practicality of the motor 100.

[0100] like Figure 3 As shown, in any of the above embodiments, the width of the partition 112 is a second width, which is greater than the thickness of the silicon steel sheet.

[0101] In this embodiment, the width of the partition 112 is the second width W5, the thickness of the plurality of silicon steel sheets constituting the rotor core 110 is the same, and the thickness of each silicon steel sheet is T. Based on this, W5 and T satisfy the following relationship: W5 > T.

[0102] like Figure 4 As shown, in any of the above embodiments, the motor 100 further includes: a stator core 140, which is cylindrical, and a rotor core 110 passing through the stator core 140; a plurality of stator teeth 142, which are disposed on the inner annular surface of the stator core 140 and extend in the radial direction of the stator core 140; the plurality of stator teeth 142 are spaced apart on the circumference of the rotor core 110, and two adjacent stator teeth 142 enclose a stator slot 144 facing the rotor core 110.

[0103] In this embodiment, the motor 100 further includes a stator core 140, which is cylindrical, and a rotor core 110 passes through the interior of the cylindrical stator core 140. The inner annular surface of the stator core 140 and the outer annular surface of the rotor core 110 are spaced apart. Furthermore, the inner annular surface of the stator core 140 is provided with a plurality of stator teeth 142 extending toward the rotor core 110. The plurality of stator teeth 142 are spaced apart circumferentially around the rotor core 110. Adjacent stator teeth 142 enclose a stator slot 144, which is U-shaped, with its opening facing the circumferential surface of the rotor core 110. The motor 100 also includes windings wound around the circumferential surface of the stator core 140 and in the stator slots 144 to cooperate with the stator core 140 to form a stator assembly. When the motor 100 is powered on, the stator assembly generates an electromagnetic field, and the rotor assembly drives the rotating shaft to rotate synchronously under the action of the electromagnetic field, so as to convert electrical energy into mechanical energy.

[0104] like Figure 1 and Figure 4 As shown, in any of the above embodiments, the width of the slot opening of the stator slot 144 is the third width; the distance between the two second mounting holes 1106 corresponding to the two second magnets 130 in the same group is the sixth spacing; the sixth spacing is less than the third width.

[0105] In this embodiment, the width of the slot opening of the stator slot 144 is the third width Tb1, and the distance between the two second mounting holes 1106 corresponding to the two second magnets 130 in the same group is the sixth spacing W1, wherein Tb1 and W1 satisfy the following relationship: W1 < Tb1.

[0106] By limiting the above-mentioned dimensional relationships, it is beneficial to accurately control the leakage flux of the motor 100 and enhance the output of the motor 100 under high-frequency overload, thereby reducing the torque pulsation of the motor 100 and enhancing the demagnetization resistance of the motor 100.

[0107] like Figure 1 and Figure 4 As shown, in any of the above embodiments, the distance between the centerlines of two adjacent stator teeth 142 is the seventh spacing; the seventh spacing is greater than the width of the second mounting hole 1106.

[0108] In this embodiment, the distance between the centerlines of two adjacent stator teeth 142 is the seventh distance Tb2, which is the distribution spacing of the stator teeth 142. The width of the second mounting hole 1106 is W2, where Tb2 and W2 satisfy the following relationship: Tb2 > W2.

[0109] By limiting the above-mentioned dimensional relationships, it is beneficial to accurately control the leakage flux of the motor 100 and enhance the output of the motor 100 under high-frequency overload, thereby reducing the torque pulsation of the motor 100 and enhancing the demagnetization resistance of the motor 100.

[0110] like Figure 1 and Figure 2 As shown, in any of the above embodiments, the surface of the first magnet 120 facing the axis of the rotor core 110 is the first surface, and the surface away from the axis of the rotor core 110 is the second surface. The first surface is a concave arc surface or a plane, and the second surface is a convex arc surface.

[0111] In this embodiment, the first magnet 120 extending along the circumferential direction of the rotor core 110 includes a first surface and a second surface. The first surface faces the axis of the rotor core 110, i.e., towards the inner side of the rotor core 110, and the second surface faces the outer circumferential surface of the rotor core 110, i.e. towards the outer side of the rotor core 110.

[0112] Based on this, the first surface can be a flat surface, or it can be a concave curved surface, and the second surface can be a convex curved surface. When the concave curved surface is selected as the first surface, the first magnet 120 is tile-shaped. When the flat surface is selected as the first surface, the first magnet 120 is bread-shaped.

[0113] The first magnet 120 protected in this embodiment can, on the one hand, work with the second magnets 130 on both sides to increase the magnetic flux density per unit area. This increases the proportion of permanent magnet torque in the output torque of the motor 100, thereby reducing the current-voltage angle of the motor 100 and improving the power factor of the motor 100. On the other hand, the second magnet 130 with the shape protected in this embodiment is easier to manufacture, which helps to reduce process complexity and production costs.

[0114] like Figure 1As shown, in any of the above embodiments, the second magnet 130 is rectangular.

[0115] In this embodiment, the second magnet 130 is rectangular, and two rectangular second magnets 130 in the same group are arranged side by side with a gap between them. Using rectangular second magnets 130 helps to reduce the process complexity and production cost of the second magnets 130.

[0116] Figure 4 This is a horizontal cross-sectional view of a motor 100 according to one embodiment of this application. The motor 100 includes a rotor core 110 with 6 poles and a stator core 140 with windings. The stator core 140 is nested in a housing made of materials such as iron or aluminum. The rotor core 110 is located on the inner axial side of the stator core 140, and the rotor core 110 is fixed to the housing by bearings, so that the rotor core 110 and the stator core 140 are coaxial.

[0117] The stator core 140 is made of stacked silicon steel sheets, and insulating components are wound around the windings of the stator core 140. Figure 4 The structure shown represents the way the three phases are distributed and wound.

[0118] The rotor core 110, like the stator core 140, is made of stacked silicon steel sheets, and the rotor core 110 is fixed to the rotating shaft. Two or more layers of mounting holes are machined at certain intervals along the circumference of the rotor core 110, and permanent magnets are inserted into each mounting hole to form magnetic poles.

[0119] Figure 4 The example uses a 36-slot stator and a 6-pole rotor, but is not limited to the above slot-pole combination.

[0120] Considering the stamping process of silicon steel sheets and their mechanical strength during use, the first mounting hole 1104 and the second mounting hole 1106 need to be chamfered.

[0121] The first mounting hole 1104 has a certain width reserved relative to the first magnet 120 to form a gap within the first mounting hole 1104. Correspondingly, the second mounting hole 1106 has a certain length reserved relative to the second magnet 130 to form a gap within the first mounting hole 1104. This layout takes into account the influence of magnetic leakage and reduces the demagnetizing effect of the demagnetizing current on the first magnet 120 and the second magnet 130 when the motor 100 outputs magnetic reluctance torque.

[0122] A protruding structure can be provided in the first mounting hole 1104 and the second mounting hole 1106 to position the first magnet 120 and the second magnet 130. Alternatively, the first magnet 120 and the second magnet 130 can be positioned by filling the gaps reserved in the first mounting hole 1104 and the second mounting hole 1106 with resin, or by inserting a non-magnetic pin into the gap.

[0123] The number of layers and whether or not the rotor core is divided are not limited to this example.

[0124] The reason for the above design is that when both the first magnet 120 and the second magnet 130 are arc-shaped facing the rotation axis (two layers of opposite arcs), the inductance Ld of the motor 100 is smaller than that of the two-layer opposite arc structure. By maintaining the gap between the first magnet 120 and the second magnet 130, the size of Lq can be maintained, and the reluctance torque of the motor 100 is also effective. If the inductance Ld is large, while keeping the inductance difference (Ld-Lq) the same as the current and Ld small (the extreme example of Ld=0), the result of calculating the angle β between the phase of the total current I and the total magnetic flux is as follows. Figure 5 As shown. By reducing the inductance Ld, the orthogonality between current and magnetic flux is improved, thereby increasing efficiency.

[0125] Wherein, θ is the angle between the combined current and the magnetic flux of the motor 100 before improvement in the related technology, θ' is the angle between the combined current and the magnetic flux of the motor 100 after improvement in this application, is is the combined current vector before improvement, is' is the combined current vector after improvement, E0 is the induced electromotive force vector, and φf is the magnetic flux vector.

[0126] in, Figure 6 Line 1 shows the induced voltage curve of a motor in the related art, line 2 shows the current curve of a motor in the related art, and line 3 shows the voltage curve of the motor 100 proposed in this application.

[0127] It should be clarified that in the claims, description, and accompanying drawings of this invention, the term "plural" refers to two or more. Unless otherwise explicitly defined, the terms "upper," "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description process, not to indicate or imply that the device or element referred to must have the described specific orientation, or be constructed and operated in a specific orientation. Therefore, these descriptions should not be construed as limiting the invention. The terms "connection," "installation," "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection between multiple objects, a detachable connection between multiple objects, or an integral connection; it can be a direct connection between multiple objects or an indirect connection between multiple objects through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this invention can be understood based on the specific circumstances of the above data.

[0128] In the claims, description, and accompanying drawings of this invention, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In the claims, description, and accompanying drawings of this invention, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0129] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An electric motor, characterized in that, include: Rotor core; The first magnet is embedded in the rotor core. There are N first magnets, which are distributed at intervals along the circumference of the rotor core, where N is an integer greater than 1. The second magnet is embedded in the rotor core, and in the circumferential direction of the rotor core, the second magnet is located between two adjacent first magnets; Specifically, the rotor core is cut off by a plane perpendicular to the axis of the rotor core to obtain a cross section; On the cross-section, the first magnet extends in the circumferential direction of the rotor core, and the second magnet extends in the radial direction of the rotor core; The rotor core also includes a shaft hole, which shares an axis with the rotor core. The diameter of the shaft hole is a first diameter, and the diameter of the rotor core is a second diameter. The rotor core also includes N first mounting holes and 2N second mounting holes, the first mounting holes and the second mounting holes are located on the periphery of the shaft hole, the N first magnets are respectively disposed in the N first mounting holes, and the 2N second magnets are respectively disposed in the 2N second mounting holes; In the radial direction of the rotor core, the distance between the first mounting hole and the shaft hole is the second spacing; The second spacing, the first diameter, and the second diameter satisfy the following relationship: RO2≥(D2-D1)÷3; Wherein, RO2 is the second spacing, D2 is the second diameter, and D1 is the first diameter; The surface of the first magnet facing the rotor core axis is called the first surface, and the surface facing away from the rotor core axis is called the second surface. The first surface is a concave arc surface or a plane, and the second surface is a convex arc surface. The first magnet is tile-shaped or bread-shaped.

2. The motor according to claim 1, characterized in that, Two second magnets form a group, and the motor includes N groups of second magnets, with two second magnets in the same group arranged side by side; In the circumferential direction of the rotor core, N second magnets and N groups of first magnets are alternately arranged.

3. The motor according to claim 2, characterized in that, The rotor core comprises multiple silicon steel sheets, which are stacked together.

4. The motor according to claim 3, characterized in that, The distance between the first mounting hole and the adjacent second mounting hole is the first spacing; The width of the adjacent second mounting hole is the first width; The first spacing is less than the first width.

5. The motor according to claim 3, characterized in that, In the radial direction of the rotor core, the distance between the first mounting hole and the outer wall of the rotor core is the third spacing, and the distance between the second mounting hole and the outer wall of the rotor core is the fourth spacing; The third spacing is greater than or equal to twice the fourth spacing; The fourth spacing is greater than the thickness of the silicon steel sheet.

6. The motor according to claim 3, characterized in that, The rotor core also includes N through holes, which connect to two second mounting holes adjacent to the first mounting hole; The through hole is located between the second mounting hole and the shaft hole.

7. The motor according to claim 6, characterized in that, In the radial direction of the rotor core, the distance between the through hole and the shaft hole is the fifth spacing. The fifth spacing, the first diameter, and the second diameter satisfy the following relationship: RO1≥(D2-D1)÷2; Wherein, RO1 is the fifth spacing, D2 is the second diameter, and D1 is the first diameter.

8. The motor according to claim 6, characterized in that, Also includes: A partition is provided inside the through hole, and the partition separates the through hole in the tangential direction of the rotor core.

9. The motor according to claim 8, characterized in that, The width of the partition is a second width, which is greater than the thickness of the silicon steel sheet.

10. The motor according to claim 3, characterized in that, Also includes: The stator core is cylindrical, and the rotor core is inserted inside the stator core. Multiple stator teeth are disposed on the inner annular surface of the stator core and extend in the radial direction of the stator core; The stator teeth are spaced apart on the circumference of the rotor core, and two adjacent stator teeth enclose a stator slot facing the rotor core.

11. The motor according to claim 10, characterized in that, The width of the stator slot opening is the third width; The distance between the two second mounting holes corresponding to the two second magnets in the same group is the sixth spacing; The sixth spacing is smaller than the third width.

12. The motor according to claim 10, characterized in that, The distance between the centerlines of two adjacent stator teeth is the seventh pitch; The seventh spacing is greater than the width of the second mounting hole.

13. The motor according to any one of claims 1 to 12, characterized in that, The second magnet is rectangular.

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