Rotor assembly and motor

Abstract

This application provides a rotor assembly and a motor. The rotor assembly includes a rotor body, a plurality of first permanent magnets, a plurality of second permanent magnets, and a plurality of third permanent magnets. The plurality of first permanent magnets are disposed between the outer surface of the rotor body and the wall of the shaft hole, and are arranged sequentially at intervals along the circumference of the shaft hole. The plurality of second permanent magnets are disposed on the outer surface of the rotor body and are arranged sequentially at intervals along the circumference of the rotor body. Each second permanent magnet corresponds to at least one first permanent magnet, and each second permanent magnet and its corresponding first permanent magnet form a magnet group. Any two adjacent magnet groups constitute a first series magnetic pole circuit structure. The plurality of third permanent magnets are disposed between the outer surface of the rotor body and the wall of the shaft hole, and are arranged sequentially at intervals along the circumference of the shaft hole. A third permanent magnet is provided between two adjacent magnet groups. Any third permanent magnet and the second permanent magnets of two adjacent magnet groups constitute a second series magnetic pole circuit structure, thereby balancing power density and response speed.

Description

Technical Field

[0001] This application relates to the field of motor technology, and in particular to a rotor assembly and a motor. Background Technology

[0002] Servo permanent magnet motors possess advantages such as small size, light weight, high torque density, high efficiency, and high power factor. Servo permanent magnet motors can be categorized into surface-mount motors and internally mounted motors based on the arrangement of the permanent magnets in the rotor. However, surface-mount motors have lower power density, while internally mounted motors have lower response speeds. Therefore, there is an urgent need for a motor that can balance power density and response speed. Utility Model Content

[0003] This application provides a rotor assembly and a motor that enable the motor to have good power density and response speed.

[0004] In a first aspect, embodiments of this application provide a rotor assembly, including:

[0005] The rotor body is provided with a shaft hole;

[0006] Multiple first permanent magnets are disposed between the outer surface of the rotor body and the wall of the shaft hole, and are arranged sequentially at intervals along the circumference of the shaft hole;

[0007] Multiple second permanent magnets are disposed on the outer surface of the rotor body and arranged sequentially at intervals along the circumference of the rotor body. Each second permanent magnet corresponds to at least one first permanent magnet. Each second permanent magnet and its corresponding first permanent magnet form a magnet group. Any two adjacent magnet groups constitute a first series magnetic pole circuit structure.

[0008] Multiple third permanent magnets are disposed between the outer surface of the rotor body and the wall of the shaft hole, and are arranged sequentially at intervals along the circumference of the shaft hole. A third permanent magnet is provided between two adjacent magnet groups, and any third permanent magnet and the second permanent magnets of the two adjacent magnet groups form a second series magnetic pole circuit structure.

[0009] In some embodiments, the outer surface of the rotor body is provided with a plurality of limiting protrusions, which are arranged sequentially at intervals along the circumference of the rotor body. Two adjacent limiting protrusions cooperate with the rotor body to form a mounting groove. Each mounting groove corresponds to a second permanent magnet, and each second permanent magnet is embedded in the corresponding mounting groove.

[0010] In some embodiments, the bottom wall of the mounting groove is provided with multiple adhesive-containing grooves, which are arranged opposite to the corresponding second permanent magnets; adhesive-containing grooves are provided at the connection between the side wall and the bottom wall of the mounting groove.

[0011] In some embodiments, the cross-section of the first permanent magnet is one of a rectangle, an ellipse, a bread shape, a circle, a triangle, or a trapezoid.

[0012] And / or, the cross-section of the second permanent magnet is one of a rectangle, an ellipse, a bread shape, a circle, a triangle, or a trapezoid;

[0013] And / or, the cross-section of the third permanent magnet is one of a rectangle, an ellipse, a bread shape, a circle, a triangle, or a trapezoid.

[0014] In some embodiments, the rotor body is provided with a plurality of first mounting holes, each first mounting hole corresponding to a first permanent magnet, and each first permanent magnet is installed in the corresponding first mounting hole;

[0015] The rotor body is provided with multiple second mounting holes, each second mounting hole corresponds to a third permanent magnet, and each third permanent magnet is installed in the corresponding second mounting hole;

[0016] Multiple second mounting holes and multiple first mounting holes are set independently.

[0017] In some embodiments, each first permanent magnet is clearance-fitted with a corresponding first mounting hole;

[0018] And / or, each third permanent magnet is clearance-fitted with the corresponding second mounting hole.

[0019] In some embodiments, each first mounting hole has two first magnetic isolation holes on its wall, and the two first magnetic isolation holes are respectively disposed on opposite sides of the first permanent magnet along the width direction of the first permanent magnet.

[0020] And / or, each second mounting hole has two second magnetic isolation holes on its wall, and the two second magnetic isolation holes are respectively located on opposite sides of the third permanent magnet along the width direction of the third permanent magnet.

[0021] In some embodiments, the first permanent magnet extends along the axial direction of the rotor body, and the length of the first permanent magnet is the same as the length of the rotor body;

[0022] And / or, the second permanent magnet extends along the axial direction of the rotor body, and the length of the second permanent magnet is the same as the length of the rotor body.

[0023] And / or, the third permanent magnet extends along the axial direction of the rotor body, and the length of the third permanent magnet is the same as the length of the rotor body.

[0024] In some embodiments, the first permanent magnet is bonded to the rotor body by a first adhesive;

[0025] And / or, the second permanent magnet is bonded to the rotor body by a second adhesive component;

[0026] And / or, the third permanent magnet is bonded to the rotor body by a third adhesive.

[0027] Secondly, embodiments of this application provide a motor, including:

[0028] case;

[0029] Stator assembly, the stator assembly is fixed inside the housing;

[0030] In any of the above embodiments, the rotor assembly is rotatably mounted within the housing via a rotating shaft.

[0031] The rotor assembly and motor provided in this application include a rotor body, a plurality of first permanent magnets, a plurality of second permanent magnets, and a plurality of third permanent magnets. The plurality of first permanent magnets are disposed between the outer surface of the rotor body and the wall of the shaft hole, and are arranged sequentially at intervals along the circumference of the shaft hole. The plurality of second permanent magnets are disposed on the outer surface of the rotor body and are arranged sequentially at intervals along the circumference of the rotor body. Each second permanent magnet corresponds to at least one first permanent magnet, and each second permanent magnet and its corresponding first permanent magnet form a magnet group. Any two adjacent magnet groups constitute a first series magnetic pole circuit structure. The plurality of third permanent magnets are disposed between the outer surface of the rotor body and the wall of the shaft hole, and are arranged sequentially at intervals along the circumference of the shaft hole. A third permanent magnet is provided between two adjacent magnet groups, and any third permanent magnet and the second permanent magnets of two adjacent magnet groups constitute a second series magnetic pole circuit structure. Compared to rotor assemblies in related technologies, the rotor assembly of this application, with a second permanent magnet arranged on the outer surface of the rotor, retains the low Q-axis (Quadrature Axis) inductance characteristic of traditional surface-mount motors. Simultaneously, the built-in structure of the first and third permanent magnets provides controllable reluctance torque, avoiding the problem of decreased response speed caused by excessive Q-axis inductance in traditional built-in motors. This allows the motor to maintain good dynamic response performance while increasing power density. Furthermore, it helps to increase the fundamental amplitude of the air gap magnetic flux density, effectively enhancing the air gap magnetic field strength, thereby increasing the motor's output torque and power density, while reducing harmonic components and improving the smoothness and efficiency of motor operation. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0033] Figure 1 This is a schematic diagram of the rotor assembly provided in an embodiment of this application.

[0034] Figure 2 for Figure 1 A schematic diagram of the main body of the rotor.

[0035] Figure 3 for Figure 1 A schematic diagram of the exploded structure of the rotor assembly.

[0036] Figure 4 A schematic diagram of the magnetic circuit of the rotor assembly provided in the embodiments of this application.

[0037] Explanation of icon numbers:

[0038] 10. Rotor assembly; 100. Rotor body; 101. Shaft hole; 102. Mounting groove; 103. Adhesive groove; 104. First mounting hole; 105. Second mounting hole; 106. First magnetic isolation hole; 107. Second magnetic isolation hole; 110. Limiting protrusion; 200. First permanent magnet; 300. Second permanent magnet; 400. Third permanent magnet; 500. Magnet assembly. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0040] The following disclosure provides numerous different embodiments or examples for implementing various structures of the present invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0041] In related technologies, servo permanent magnet motors possess advantages such as small size, light weight, high torque density, high efficiency, and high power factor. Servo permanent magnet motors can be categorized into surface-mounted motors and internally mounted motors based on the arrangement of the permanent magnets in the rotor. However, the inventors have discovered that surface-mounted motors have lower power density, while internally mounted motors have lower response speeds. Therefore, there is an urgent need for a motor that can balance power density and response speed.

[0042] In view of this, please refer to Figure 1This application provides a rotor assembly 10, which includes a rotor body 100, a plurality of first permanent magnets 200, a plurality of second permanent magnets 300, and a plurality of third permanent magnets 400. The plurality of first permanent magnets 200 are disposed between the outer surface of the rotor body 100 and the wall of the shaft hole 101, and are arranged sequentially at intervals along the circumference of the shaft hole 101. The plurality of second permanent magnets 300 are disposed on the outer surface of the rotor body 100 and are arranged sequentially at intervals along the circumference of the rotor body 100. Each second permanent magnet 300 corresponds to at least one first permanent magnet 200, and each second permanent magnet 300 and its corresponding first permanent magnet 200 form a magnet group 500. Any two adjacent magnet groups 500 constitute a first series magnetic pole circuit structure. Multiple third permanent magnets 400 are disposed between the outer surface of the rotor body 100 and the hole wall of the shaft hole 101, and are arranged sequentially at intervals along the periphery of the shaft hole 101. A third permanent magnet 400 is provided between two adjacent magnet groups 500. Any third permanent magnet 400 and the second permanent magnets 300 of the two adjacent magnet groups 500 form a second series magnetic pole circuit structure.

[0043] Specifically, the rotor body 100 is a rotor core. The shaft hole 101 of the rotor body 100 can be used to mate with the motor shaft for installation. It has an overall cylindrical structure and is adapted to the stator structure to form a closed magnetic circuit. Multiple first permanent magnets 200 are embedded inside the rotor body 100 to enhance the main magnetic field and participate in forming a controllable reluctance torque path.

[0044] Each second permanent magnet 300 corresponds to one first permanent magnet 200, and the two together form a magnet group 500. Adjacent magnet groups 500 form a first series magnetic pole loop structure, making the magnetic flux path more concentrated and further enhancing the magnetomotive force output capability. Each third permanent magnet 400 is located between two adjacent magnet groups 500 and, together with the second permanent magnet 300 in the adjacent magnet group 500, forms a second series magnetic pole loop structure, further optimizing the magnetic flux path distribution and improving the overall output torque of the motor. All permanent magnets (e.g., the first permanent magnet 200, the second permanent magnet 300, and the third permanent magnet 400) are made of high-energy-level rare-earth permanent magnet materials, such as neodymium iron boron, which have excellent remanence and coercivity characteristics and can provide a stable strong magnetic field.

[0045] Regarding the magnetic pole arrangement, the polarities of the second permanent magnet 300, the first permanent magnet 200, and the third permanent magnet 400 are arranged in an alternating N and S pole pattern, forming a complete closed-loop magnetic circuit to ensure the uniformity and stability of the magnetic field during motor operation. In other words, along the radial direction of the rotor body 100, the polarities of the second permanent magnet 300 and the first permanent magnet 200 in each magnet group 500 are arranged in an alternating N and S pole pattern. Along the circumferential direction of the rotor body 100, the polarities of multiple third permanent magnets 400 are arranged in an alternating N and S pole pattern.

[0046] Thus, compared to rotor assemblies in related technologies, the rotor assembly 10 of this application, with the second permanent magnet 300 arranged on the outer surface of the rotor, retains the low Q-axis (Quadrature Axis) inductance characteristic of traditional surface-mount motors. Simultaneously, the built-in structure of the first permanent magnet 200 and the third permanent magnet 400 provides controllable reluctance torque, avoiding the problem of decreased response speed caused by excessive Q-axis inductance in traditional built-in motors. This allows the motor to maintain good dynamic response performance while increasing power density. Furthermore, it helps to increase the fundamental amplitude of the air gap magnetic flux density, effectively enhancing the air gap magnetic field strength, thereby increasing the motor's output torque and power density, while reducing harmonic components and improving the smoothness and efficiency of motor operation.

[0047] Moreover, by rationally arranging three types of permanent magnets inside and outside the rotor body 100 and constructing a first series magnetic pole circuit structure and a second series magnetic pole circuit structure, this application effectively enhances the air gap magnetic field strength, improves the output torque of the motor, and thus significantly improves the power density of the motor.

[0048] Meanwhile, the rotor assembly 10 of this application, by employing a composite permanent magnet layout on the surface and inside the rotor body 100, helps to optimize the magnetic field distribution, reduce cogging torque fluctuations, reduce vibration and noise during motor operation, and improve the overall machine's operational stability.

[0049] Secondly, from an electromagnetic design perspective, since only one slot is set between each adjacent magnet group 500 for installing the third permanent magnet 400, the magnetic resistance path in this area is shorter, the magnetic circuit is more concentrated, and it helps to reduce magnetic resistance, thereby significantly improving the efficiency of magnetic flux passage.

[0050] Please see Figure 1 and Figure 4In some embodiments, the magnetic flux loop path of the first series magnetic pole loop structure passes through the following structures in sequence: second permanent magnet 300 (the second permanent magnet 300 of one of the magnet groups 500), rotor body 100, first permanent magnet 200 (the first permanent magnet 200 of one of the magnet groups 500), rotor body 100, first permanent magnet 200 (the first permanent magnet 200 of another magnet group 500), rotor body 100, second permanent magnet 300 (the second permanent magnet 300 of another magnet group 500), and air gap (the external environment of rotor body 100), thereby forming a closed magnetic pole loop.

[0051] Please continue reading. Figure 1 and Figure 4 In some embodiments, the magnetic flux loop path of the second series magnetic pole loop structure passes through the following structures in sequence: second permanent magnet 300 (the second permanent magnet 300 of one of the magnet groups 500), rotor body 100, third permanent magnet 400, rotor body 100, second permanent magnet 300 (the second permanent magnet 300 of another magnet group 500), and air gap, thereby forming a closed magnetic pole loop.

[0052] Please see Figure 1 and Figure 2 In some embodiments, a plurality of limiting protrusions 110 are provided on the outer surface of the rotor body 100. The plurality of limiting protrusions 110 are arranged sequentially at intervals along the circumference of the rotor body 100. Two adjacent limiting protrusions 110 cooperate with the rotor body 100 to form a mounting groove 102. Each mounting groove 102 corresponds to a second permanent magnet 300. Each second permanent magnet 300 is embedded in the corresponding mounting groove 102.

[0053] Each second permanent magnet 300 is embedded in the corresponding mounting groove 102 and is positioned by the limiting protrusion 110 to prevent the permanent magnet from shifting or falling off due to centrifugal force during high-speed rotation of the motor, thereby improving the overall structural strength and operational stability of the rotor assembly 10.

[0054] Furthermore, the height and width of the limiting protrusion 110 are optimized based on the dimensions of the second permanent magnet 300 and the mechanical stress distribution during motor operation to ensure reliable mechanical fixation without affecting the magnetic field distribution. In addition, the limiting protrusion 110 also provides a certain degree of magnetic shielding, helping to guide the magnetic flux path, reduce magnetic flux leakage, and improve the electromagnetic performance of the motor.

[0055] Please see Figure 2In some embodiments, the bottom wall of the mounting groove 102 is provided with an adhesive-containing groove 103, which is disposed opposite to the corresponding second permanent magnet 300. The adhesive-containing groove 103 is a recessed structure, formed on the bottom wall surface of the mounting groove 102, for accommodating adhesive materials, such as high-strength epoxy resin or other structural adhesives suitable for motors operating in high-temperature and high-humidity environments.

[0056] By setting the adhesive reservoir 103 so that it faces the mounting position of the second permanent magnet 300, adhesive can be injected into the reservoir 103 during assembly, allowing the adhesive to fully fill the gap between the permanent magnet and the rotor body 100, thereby enhancing the bonding area and adhesion between the two. This structure not only improves the centrifugal resistance of the second permanent magnet 300 under high-speed rotation conditions, but also effectively prevents loosening or detachment caused by vibration or temperature changes, thus improving the overall structural stability and service life of the rotor assembly 10.

[0057] In addition, the design of the adhesive groove 103 can also play a certain role in stress buffering, absorbing some of the mechanical stress caused by the difference in thermal expansion during motor operation, avoiding the problem of the second permanent magnet 300 failing to be fixed due to the brittleness of the adhesive layer, and further enhancing the reliability of motor operation under complex working conditions.

[0058] In some embodiments, there are multiple adhesive receiving grooves 103, and adhesive receiving grooves 103 are provided at the connection between the side wall and the bottom wall of the mounting groove 102.

[0059] The design of multiple adhesive reservoirs 103 not only increases the storage space for adhesive and improves the bonding area, but also allows the adhesive to be more evenly distributed between the permanent magnet and the rotor body 100 during the curing process, thereby improving the overall bonding strength and enhancing the second permanent magnet 300's resistance to detachment under high-speed operation.

[0060] Secondly, the adhesive groove 103 located at the junction of the side wall and bottom wall of the mounting groove 102 helps to remove metal burrs or processing residues in the corners of the mounting groove 102 during the processing, improves assembly accuracy, reduces bonding failure caused by foreign objects, and further enhances the manufacturing consistency and long-term operational stability of the motor.

[0061] Please see Figure 2 and Figure 3 In some embodiments, the rotor body 100 is provided with a plurality of first mounting holes 104, each first mounting hole 104 corresponding to a first permanent magnet 200, and each first permanent magnet 200 is installed in the corresponding first mounting hole 104, such that each first permanent magnet 200 is embedded and fixed in the corresponding first mounting hole 104.

[0062] The rotor body 100 is provided with a plurality of second mounting holes 105, each second mounting hole 105 corresponds to a third permanent magnet 400, each third permanent magnet 400 is installed in the corresponding second mounting hole 105, and each third permanent magnet 400 is embedded and fixed in the corresponding second mounting hole 105.

[0063] Multiple second mounting holes 105 and multiple first mounting holes 104 are independently provided. That is, they do not share the same set of holes in terms of spatial layout, nor are they directly connected. This design not only facilitates processing and manufacturing, but also provides each permanent magnet with its own dedicated mounting path for different positions and functions, which is conducive to achieving precise control of magnetic circuit distribution.

[0064] Specifically, multiple first mounting holes 104 are typically evenly distributed circumferentially within the rotor body 100 along the shaft hole 101, and are used to install multiple first permanent magnets 200 respectively. Their main function is to enhance the main magnetic field and participate in the formation of a controllable reluctance torque path. The second mounting holes 105 are located in the area between adjacent magnet groups 500 and are used to install third permanent magnets 400 to construct a second series magnetic pole circuit structure, thereby further improving the overall output performance of the motor.

[0065] The first mounting hole 104 and the second mounting hole 105 are set independently, which can effectively avoid magnetic circuit disorder caused by structural interference and ensure a clearer and more orderly magnetic field distribution among the permanent magnets. In addition, this structure can also improve assembly accuracy and process flexibility, and facilitate local structural adjustments for different application requirements without affecting the magnetic circuit performance of other parts.

[0066] Please see Figure 2 and Figure 3 In some embodiments, each first permanent magnet 200 is clearance-fitted with its corresponding first mounting hole 104, meaning a small gap is left between the outer contour of the first permanent magnet 200 and the inner wall of the first mounting hole 104. During assembly, the clearance fit can effectively reduce the assembly difficulty between the first permanent magnet 200 and the rotor body 100, reduce problems such as jamming and scratching caused by machining errors or geometric tolerances, and improve assembly efficiency and yield.

[0067] Furthermore, by reasonably controlling the size of the gap between the first permanent magnet 200 and the hole wall of the first mounting hole 104, sufficient space can be provided for subsequent injection of adhesive materials (such as epoxy resin) without affecting the magnetic field distribution. This allows the adhesive to fully fill the gap between the first permanent magnet 200 and the hole wall of the first mounting hole 104, thereby enhancing the adhesion and shear resistance between the two and improving the structural stability of the first permanent magnet 200 under high-speed rotation.

[0068] Furthermore, the clearance fit between the first permanent magnet 200 and the wall of the first mounting hole 104 provides a certain degree of thermal expansion adaptability. During motor operation, due to temperature rise, the first permanent magnet 200 and the rotor core may experience varying degrees of thermal expansion. The clearance fit between the first permanent magnet 200 and the wall of the first mounting hole 104 provides a buffer space for this thermal expansion, preventing structural failures caused by differences in material expansion, thereby extending the motor's service life.

[0069] In some embodiments, each third permanent magnet 400 is clearance-fitted with the corresponding second mounting hole 105, meaning that a small gap is left between the outer contour of the third permanent magnet 400 and the inner wall of the second mounting hole 105. During assembly, the clearance fit can effectively reduce the assembly difficulty between the third permanent magnet 400 and the rotor body 100, reduce problems such as jamming and scratching caused by machining errors or geometric tolerances, and improve assembly efficiency and yield.

[0070] Furthermore, by reasonably controlling the gap between the third permanent magnet 400 and the hole wall of the second mounting hole 105, sufficient space can be provided for subsequent injection of adhesive materials (such as epoxy resin) without affecting the magnetic field distribution. This allows the adhesive to fully fill the gap between the third permanent magnet 400 and the hole wall of the second mounting hole 105, thereby enhancing the adhesion and shear resistance between the two and improving the structural stability of the third permanent magnet 400 under high-speed rotation.

[0071] Furthermore, the clearance fit between the third permanent magnet 400 and the wall of the second mounting hole 105 provides a certain degree of thermal expansion adaptability. During motor operation, due to temperature rise, the third permanent magnet 400 and the rotor core may experience varying degrees of thermal expansion. The clearance fit between the third permanent magnet 400 and the wall of the second mounting hole 105 provides a buffer space for this thermal expansion, preventing structural failures caused by differences in material expansion, thereby extending the motor's service life.

[0072] In some embodiments, each first mounting hole 104 has two first magnetic isolation holes 106 on its wall. The two first magnetic isolation holes 106 are respectively disposed on opposite sides of the first permanent magnet 200 along the width direction of the first permanent magnet 200. Specifically, the first magnetic isolation hole 106 is a through-hole structure opened inside the rotor body 100. Its shape can be designed as circular, elliptical, or polygonal according to the processing requirements, and its position is directly opposite the edge area of ​​the corresponding first permanent magnet 200. Since the permeability of air is low, the first magnetic isolation hole 106 can be used as a non-magnetic area. It can effectively block the magnetic coupling effect between adjacent magnetic poles without significantly affecting the main magnetic flux path, reduce the magnetic flux short circuit phenomenon, and improve the main magnetic flux utilization rate.

[0073] Furthermore, the first magnetic flux isolation holes 106 located on both sides of the first permanent magnet 200 can guide the magnetic flux to flow in a concentrated manner towards the air gap, thereby enhancing the fundamental amplitude of the air gap magnetic flux density and improving the motor's output torque and power density. At the same time, the first magnetic flux isolation holes 106 can also optimize the magnetic field distribution, reduce cogging torque fluctuations, improve the smoothness of motor operation, and reduce vibration and noise.

[0074] Furthermore, under high-speed or high-frequency operating conditions, the first magnetic isolation through-hole 106 also has the function of suppressing eddy current losses. Since the iron core area around the first permanent magnet 200 is prone to eddy current heating due to harmonic magnetic fields, the presence of the first magnetic isolation through-hole 106 can effectively cut off the eddy current loop path, thereby reducing local temperature rise and improving motor efficiency and reliability.

[0075] Please continue reading. Figure 2 and Figure 3 In some embodiments, each second mounting hole 105 has two second magnetic isolation holes 107 on its hole wall, and the two second magnetic isolation holes 107 are respectively disposed on opposite sides of the third permanent magnet 400 along the width direction of the third permanent magnet 400.

[0076] Specifically, the second magnetic isolation through-hole 107 is a through-hole structure opened inside the rotor body 100. Its shape can be designed as circular, elliptical, or polygonal, etc., according to the processing requirements, and its position is directly opposite the edge area of ​​the corresponding permanent magnet. Since the permeability of air is low, the second magnetic isolation through-hole 107 can be used as a non-magnetic area. It can effectively block the magnetic coupling effect between adjacent magnetic poles without significantly affecting the main magnetic flux path, reduce the phenomenon of magnetic flux short circuit, and improve the utilization rate of main magnetic flux.

[0077] Furthermore, the second magnetic flux isolation holes 107 located on both sides of the third permanent magnet 400 can guide the magnetic flux to flow in a concentrated manner towards the air gap, thereby enhancing the fundamental amplitude of the air gap magnetic flux density and improving the motor's output torque and power density. At the same time, the second magnetic flux isolation holes 107 can also optimize the magnetic field distribution, reduce cogging torque fluctuations, improve the smoothness of motor operation, and reduce vibration and noise.

[0078] Furthermore, under high-speed or high-frequency operating conditions, the second magnetic isolation hole 107 also has the function of suppressing eddy current losses. Since the iron core area around the third permanent magnet 400 is prone to eddy current heating due to harmonic magnetic fields, the presence of the second magnetic isolation hole 107 can effectively cut off the eddy current loop path, thereby reducing local temperature rise and improving motor efficiency and reliability.

[0079] In some embodiments, the first permanent magnet 200 extends along the axial direction of the rotor body 100, and the length of the first permanent magnet 200 is the same as the length of the rotor body 100. That is, the length of the first permanent magnet 200 is equal to or approximately equal to the length of the rotor body 100, so that the first permanent magnet 200 can participate in the establishment of the magnetic field and the formation of the magnetic circuit throughout the axial range of the entire rotor body 100, thereby ensuring the uniformity and continuity of the magnetic field distribution, improving the effective magnetic flux density of the motor, and thus enhancing the output torque and power density of the motor.

[0080] In some embodiments, the second permanent magnet 300 extends along the axial direction of the rotor body 100, and the length of the second permanent magnet 300 is the same as the length of the rotor body 100. That is, the length of the second permanent magnet 300 is equal to or approximately equal to the length of the rotor body 100, so that the second permanent magnet 300 can participate in the establishment of the magnetic field and the formation of the magnetic circuit throughout the entire axial range of the rotor body 100, thereby ensuring the uniformity and continuity of the magnetic field distribution, improving the effective magnetic flux density of the motor, and enhancing the output torque and power density.

[0081] In some embodiments, the third permanent magnet 400 extends along the axial direction of the rotor body 100, and the length of the third permanent magnet 400 is the same as the length of the rotor body 100. That is, the length of the third permanent magnet 400 is equal to or approximately equal to the length of the rotor body 100, so that the third permanent magnet 400 can participate in the establishment of the magnetic field and the formation of the magnetic circuit throughout the axial range of the entire rotor body 100, thereby ensuring the uniformity and continuity of the magnetic field distribution, improving the effective magnetic flux density of the motor, and enhancing the output torque and power density.

[0082] In some embodiments, the first permanent magnet 200 is bonded to the rotor body 100 by a first adhesive. The first adhesive is preferably a structural adhesive with high strength and good temperature resistance, such as an epoxy resin adhesive, which can effectively withstand the centrifugal force, thermal stress and mechanical vibration generated during motor operation.

[0083] Furthermore, the first adhesive not only firmly bonds the first permanent magnet 200 to the rotor body 100, but also fills the tiny gap between the first permanent magnet 200 and the first mounting hole 104, improving the bonding strength of the contact surface and preventing loosening due to assembly errors or deformation. In addition, this adhesive material has a certain buffering performance, which helps absorb the internal stress caused by the difference in thermal expansion coefficients between different materials under conditions of frequent motor start-stop or load changes, thereby extending the service life of the permanent magnet.

[0084] In terms of assembly process, the first bonding component uses an adhesive fixing method, which avoids the problems of magnet damage or local demagnetization that may occur with traditional pressing or welding processes, thus ensuring the integrity of the magnetic properties of the permanent magnet material. At the same time, this method also simplifies the overall structural design of the rotor assembly 10, reduces processing difficulty and manufacturing costs, and is conducive to mass production.

[0085] In some embodiments, the second permanent magnet 300 is bonded to the rotor body 100 by a second adhesive. The second adhesive is preferably a structural adhesive with high strength and good temperature resistance, such as an epoxy resin adhesive, which can effectively withstand the centrifugal force, thermal stress and mechanical vibration generated during motor operation.

[0086] Furthermore, the second adhesive not only firmly bonds the second permanent magnet 300 to the rotor body 100, but also fills the tiny gaps between the second permanent magnet 300 and the mounting groove 102, improving the bonding strength of the contact surfaces and preventing loosening due to assembly errors or deformation. In addition, this adhesive material has a certain buffering performance, which helps absorb the internal stress caused by the difference in thermal expansion coefficients between different materials under conditions of frequent motor start-stop or load changes, thereby extending the service life of the permanent magnet.

[0087] In terms of assembly process, the second adhesive component, by adopting an adhesive fixing method, avoids the problems of magnet damage or local demagnetization that may occur with traditional pressing or welding processes, ensuring the integrity of the magnetic properties of the permanent magnet material. At the same time, this method also simplifies the overall structural design of the rotor assembly 10, reduces processing difficulty and manufacturing costs, and is conducive to achieving mass production.

[0088] In some embodiments, the third permanent magnet 400 is bonded to the rotor body 100 by a third adhesive. The third adhesive is preferably a structural adhesive with high strength and good temperature resistance, such as an epoxy resin adhesive, which can effectively withstand the centrifugal force, thermal stress and mechanical vibration generated during motor operation.

[0089] Furthermore, the third adhesive not only firmly bonds the third permanent magnet 400 to the rotor body 100, but also fills the tiny gap between the third permanent magnet 400 and the second mounting hole 105, improving the bonding strength of the contact surface and preventing loosening due to assembly errors or deformation. In addition, this adhesive material has a certain buffering performance, which helps absorb the internal stress caused by the difference in thermal expansion coefficients between different materials under conditions of frequent motor start-stop or load changes, thereby extending the service life of the permanent magnet.

[0090] In terms of assembly process, the third adhesive component, by adopting an adhesive fixing method, avoids the problems of magnet damage or local demagnetization that may occur with traditional press-fitting or welding processes, ensuring the integrity of the magnetic properties of the permanent magnet material. At the same time, this method also simplifies the overall structural design of the rotor assembly 10, reduces processing difficulty and manufacturing costs, and is conducive to achieving mass production.

[0091] In some embodiments, the cross-section of the first permanent magnet 200 is one of a rectangle, ellipse, bread shape, circle, triangle, or trapezoid. Specifically, the first permanent magnet 200 is embedded inside the rotor body 100, and its cross-section can be selected from any of the above shapes according to the magnetic circuit design objectives. For example, using a rectangular cross-section can increase the magnet filling rate and enhance the main magnetic flux output; using an ellipse or bread shape helps to reduce the risk of local magnetic saturation and improve the uniformity of the magnetic field; while using a circular or trapezoidal cross-section is more conducive to assembly positioning and stress dispersion.

[0092] In some embodiments, the cross-section of the second permanent magnet 300 is one of a rectangle, ellipse, bread shape, circle, triangle, or trapezoid. Specifically, the second permanent magnet 300 is arranged on the outer surface of the rotor body 100, and its cross-section also adopts one of the above-mentioned shapes. Since the second permanent magnet 300 directly participates in the construction of the air gap magnetic field, its shape selection has a direct impact on the motor output torque and power density. For example, using an ellipse or bread shape can improve the magnetic flux distribution and reduce cogging torque fluctuations; using a triangle or trapezoid can optimize the magnet layout within a limited space and improve utilization.

[0093] In some embodiments, the cross-section of the third permanent magnet 400 is one of a rectangle, ellipse, bread shape, circle, triangle, or trapezoid. Specifically, as an important component of the series magnetic pole circuit, the cross-section of the third permanent magnet 400 can also be selected from the above shapes. By reasonably matching the shape combination between the third permanent magnet 400 and the adjacent second permanent magnet 300, the magnetic flux path can be effectively guided, the coupling effect between magnetic poles can be enhanced, and thus the overall performance of the motor can be further improved.

[0094] This application also provides an electric motor, which may include a housing, a stator assembly, and a rotor assembly 10. The rotor assembly 10 can be implemented with reference to the above embodiments. The rotor assembly 10 is rotatably disposed within the housing via a rotating shaft.

[0095] The stator assembly is fixedly installed inside the housing and typically consists of a stator core and windings. The stator core is formed by a stamping and lamination process and has multiple stator teeth evenly distributed circumferentially for winding electromagnetic coils; the windings are wound on the stator teeth according to a predetermined number of turns and wiring method. When energized, they generate an alternating magnetic field, driving the rotor to rotate.

[0096] The rotor assembly 10 is rotatably mounted in the housing via a shaft and maintains a certain air gap with the stator assembly. The rotor assembly 10 includes a rotor body 100, multiple first permanent magnets 200, second permanent magnets 300, and third permanent magnets 400. The permanent magnets are arranged on the rotor body 100 in a specific pattern to form multiple cooperating magnetic pole circuits, thereby significantly improving the power density and response speed of the motor.

[0097] Furthermore, the rotating shaft is tightly fitted to the rotor body 100 and supported by bearings within the end caps of the housing, ensuring good rotational stability of the rotor assembly 10 during high-speed operation. In addition, the motor can be equipped with auxiliary components such as encoders, fans, or cooling systems according to actual application requirements to meet the control accuracy and heat dissipation requirements under different operating conditions.

[0098] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0099] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “” used herein may also mean including the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof.

[0100] The above are merely specific embodiments of this utility model, enabling those skilled in the art to understand or implement it. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this utility model. Therefore, this utility model is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A rotor assembly, characterized in that, include: The rotor body is provided with a shaft hole; Multiple first permanent magnets are disposed between the outer surface of the rotor body and the wall of the shaft hole, and are arranged sequentially at intervals along the circumference of the shaft hole; Multiple second permanent magnets are disposed on the outer surface of the rotor body and arranged sequentially at intervals along the circumference of the rotor body. Each second permanent magnet corresponds to at least one first permanent magnet. Each second permanent magnet and its corresponding first permanent magnet form a magnet group. Any two adjacent magnet groups constitute a first series magnetic pole circuit structure. as well as Multiple third permanent magnets are disposed between the outer surface of the rotor body and the wall of the shaft hole, and are arranged sequentially at intervals along the circumference of the shaft hole. A third permanent magnet is provided between two adjacent magnet groups, and any third permanent magnet and the second permanent magnets of the two adjacent magnet groups form a second series magnetic pole circuit structure.

2. The rotor assembly according to claim 1, characterized in that, The outer surface of the rotor body is provided with a plurality of limiting protrusions, which are arranged sequentially at intervals along the circumference of the rotor body. Two adjacent limiting protrusions cooperate with the rotor body to form a mounting groove. Each mounting groove corresponds to a second permanent magnet, and each second permanent magnet is embedded in the corresponding mounting groove.

3. The rotor assembly according to claim 2, characterized in that, The bottom wall of the mounting groove is provided with a plurality of adhesive-containing grooves, and the adhesive-containing grooves are arranged opposite to the corresponding second permanent magnets; The adhesive groove is provided at the connection between the side wall and the bottom wall of the mounting groove.

4. The rotor assembly according to claim 1, characterized in that, The cross-section of the first permanent magnet is one of a rectangle, an ellipse, a bread shape, a circle, a triangle, or a trapezoid; And / or, the cross-section of the second permanent magnet is one of a rectangle, an ellipse, a bread shape, a circle, a triangle, or a trapezoid; And / or, the cross-section of the third permanent magnet is one of a rectangle, an ellipse, a bread shape, a circle, a triangle, or a trapezoid.

5. The rotor assembly according to claim 1, characterized in that, The rotor body is provided with a plurality of first mounting holes, each first mounting hole corresponding to a first permanent magnet, and each first permanent magnet is installed in the corresponding first mounting hole; The rotor body is provided with a plurality of second mounting holes, each second mounting hole corresponding to one third permanent magnet, and each third permanent magnet is installed in the corresponding second mounting hole; The plurality of second mounting holes and the plurality of first mounting holes are provided independently.

6. The rotor assembly according to claim 5, characterized in that, Each of the first permanent magnets is clearance-fitted with the corresponding first mounting hole; And / or, each of the third permanent magnets is clearance-fitted with the corresponding second mounting hole.

7. The rotor assembly according to claim 5, characterized in that, Each of the first mounting holes has two first magnetic isolation holes on its wall, and the two first magnetic isolation holes are respectively arranged on opposite sides of the first permanent magnet along the width direction of the first permanent magnet. And / or, each of the second mounting holes has two second magnetic isolation holes on its wall, and the two second magnetic isolation holes are respectively disposed on opposite sides of the third permanent magnet along the width direction of the third permanent magnet.

8. The rotor assembly according to claim 1, characterized in that, The first permanent magnet extends along the axial direction of the rotor body, and the length of the first permanent magnet is the same as the length of the rotor body; And / or, the second permanent magnet extends along the axial direction of the rotor body, and the length of the second permanent magnet is the same as the length of the rotor body; And / or, the third permanent magnet extends along the axial direction of the rotor body, and the length of the third permanent magnet is the same as the length of the rotor body.

9. The rotor assembly according to claim 1, characterized in that, The first permanent magnet is bonded to the rotor body by a first adhesive component; And / or, the second permanent magnet is bonded to the rotor body by a second adhesive; And / or, the third permanent magnet is bonded to the rotor body by a third adhesive.

10. An electric motor, characterized in that, include: case; A stator assembly, the stator assembly being fixed within the housing; as well as The rotor assembly according to any one of claims 1 to 9 is rotatably disposed within the housing via a rotating shaft.

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