Permanent magnet motor rotor end plate, rotor assembly and permanent magnet motor thereof

Abstract

The invention discloses a permanent magnet motor rotor end plate which is characterized in that the permanent magnet motor rotor end plate comprises an end plate body, the end plate body is an annular non-ferromagnetic metal plate, and a plurality of wind blades distributed in the circumferential direction are arranged on the end face of the end plate body; the wind blades are formed by outwards bending part of the plate body of the end plate body, and the blade main body is integrally connected with the end plate body through a bent connecting part; the blade body protrudes relative to the end face of the end plate body, so that a through hole is formed in the position, corresponding to the blade body, of the end plate body. According to the invention, the annular non-ferromagnetic metal end plate body is integrally stamped and bent to form a plurality of wind blades, so that the rotor end plate has the capability of active heat dissipation on the basis of realizing the basic functions of fixing a permanent magnet and the like, and the wind blades can drive airflow to form forced convection when a rotor rotates, so that the rotor end plate is more energy-saving and environment-friendly. Heat generated by the rotor core and the permanent magnets is effectively taken away, and the heat dissipation performance of the permanent magnet motor rotor is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric machines, in particular to a permanent magnet motor rotor end plate, a rotor assembly and a permanent magnet motor thereof. BACKGROUND

[0002] Permanent magnet motors are widely used in industrial drives and new energy vehicles due to their high efficiency and high power density. Unlike traditional squirrel cage induction motors, the rotor of a permanent magnet motor is composed of a rotor core and permanent magnets arranged therein. In order to prevent axial displacement of the permanent magnets and facilitate dynamic balance adjustment of the rotor, a rotor end plate is usually provided at both ends of the rotor core.

[0003] Currently, the rotor end plate of a permanent magnet motor generally adopts a circular ring flat structure. Although this structure has a simple manufacturing process and low cost, it still has several deficiencies in practical application. On the one hand, during operation of the permanent magnet motor, the temperature of the rotor will continue to rise due to the magnetic hysteresis loss of the rotor core, the eddy current loss of the permanent magnets and the thermal radiation of the stator side. Current thermal management focuses on heat dissipation design within the motor, but this design cannot effectively improve the heat dissipation of the rotor. On the other hand, during dynamic balance verification of the rotor, dynamic balance cement is usually used for weight compensation. However, under the working condition of long-term high-speed operation of the rotor, the dynamic balance cement has the risk of falling off, affecting the long-term stability of the dynamic balance of the rotor.

[0004] Therefore, how to improve the heat dissipation performance of the rotor of a permanent magnet motor and improve the long-term reliability of the dynamic balance while maintaining low manufacturing cost is a technical problem to be solved in the field. SUMMARY

[0005] The main purpose of the present application is to provide a permanent magnet motor rotor end plate, a rotor assembly and a permanent magnet motor thereof to solve the above technical problems.

[0006] In a first aspect, the present application provides a permanent magnet motor rotor end plate, characterized in that it comprises an end plate body, which is an annular non-ferromagnetic metal plate. A plurality of wind blades are distributed circumferentially on the end face of the end plate body. The wind blades are formed by bending part of the plate body of the end plate body outward. The wind blades include a blade body and a bending connection part. The blade body is integrally connected with the end plate body through the bending connection part. The blade body is raised relative to the end face of the end plate body, and a through hole is formed on the end plate body corresponding to the position of the blade body. Release grooves are provided on both sides of the bending connection part, which penetrate the end plate body along the thickness direction of the end plate body.

[0007] In a second aspect, the application further provides a permanent magnet motor rotor assembly, comprising a rotor core, wherein a permanent magnet is arranged in the rotor core, and rotor end plates are arranged at axial ends of the rotor core respectively, and the rotor end plate is the permanent magnet motor rotor end plate as described in the first aspect.

[0008] In a third aspect, the application further provides a permanent magnet motor, comprising a rotor assembly, wherein the rotor assembly is the permanent magnet motor rotor assembly as described in the second aspect.

[0009] The beneficial technical effects of the application are as follows: The application forms multiple fan blades by integrally stamping and bending on the annular non-ferromagnetic metal end plate body, so that the rotor end plate has the ability of active heat dissipation on the basis of realizing the basic functions of fixing the permanent magnet, and the fan blades can drive air flow to form forced convection when the rotor rotates, effectively taking away the heat generated by the rotor core and the permanent magnet, improving the heat dissipation performance of the permanent magnet motor rotor. Meanwhile, the fan blades are integrally formed by bending part of the plate body of the end plate body, without the need for secondary connection processes such as welding or riveting, simplifying the manufacturing process and reducing the production cost. In addition, the release grooves are arranged on both sides of the bending connection part, effectively releasing the bending stress, avoiding stress concentration, improving the structural strength and flatness of the product, and ensuring the long-term reliability of the rotor end plate and dynamic balance. BRIEF DESCRIPTION OF DRAWINGS

[0010] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0011] Figure 1 A three-dimensional schematic diagram of the permanent magnet motor rotor end plate provided by the embodiment of the application; Figure 2 Another schematic diagram of the permanent magnet motor rotor end plate provided by the embodiment of the application; Figure 3 A schematic diagram of the permanent magnet motor rotor assembly provided by the embodiment of the application; Figure 2 An enlarged schematic diagram of A in the figure; Figure 4 A schematic diagram of the permanent magnet motor rotor assembly provided by the embodiment of the application; Figure 5 An assembly schematic diagram of two rotor end plates in the permanent magnet motor rotor assembly provided by the embodiment of the application; Figure 6 A schematic block diagram of the permanent magnet motor provided by the embodiment of the application.

[0012] Explanation of reference signs: In the diagram: 10-End plate body, 11-Through hole, 12-Release groove, 13-Weight reduction groove, 14-Assembly through hole, 20-Wind blade, 21-Blade body, 211-Notch, 22-Bending connection, 30-Rotor core, 31-Permanent magnet, 32-Rotor end plate, 40-Fastener, 50-Permanent magnet motor, 51-Housing, 52-Stator assembly, 53-Rotor assembly. Detailed Implementation

[0013] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0014] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0015] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0016] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0017] like Figures 1 to 3 As shown, this embodiment of the invention provides a permanent magnet motor rotor end plate, which is installed at the axial end of the permanent magnet motor rotor core 30 to limit the axial displacement of the permanent magnet 31 in the rotor core 30 and drive airflow to assist in rotor heat dissipation when the rotor rotates.

[0018] The permanent magnet motor rotor end plate includes an end plate body 10, which is an annular non-ferromagnetic metal plate. Multiple fan blades 20 are provided on the end face of the end plate body 10 in a circumferentially distributed manner. The fan blade 20 is formed by outwardly bending part of the plate body of the end plate body 10. The fan blade 20 comprises a blade body 21 and a bent connecting portion 22, and the blade body 21 is integrally connected with the end plate body 10 through the bent connecting portion 22. The blade body 21 is protruded relative to the end face of the end plate body 10, and a through hole 11 is formed on the end plate body 10 at a position corresponding to the blade body 21. The bent connecting portion 22 is provided with a release groove 12 on each side, and the release groove 12 penetrates the end plate body 10 along the thickness direction of the end plate body 10.

[0019] In the embodiment, the permanent magnet motor rotor end plate comprises an end plate body 10. The end plate body 10 is annular as a whole, has a first end face and a second end face arranged oppositely, and has an inner circumferential edge on the inner side in the radial direction and an outer circumferential edge on the outer side in the radial direction. A central hole surrounded by the inner circumferential edge of the end plate body 10 is used for passing through a rotor shaft.

[0020] The end plate body 10 is made of a non-ferromagnetic metal plate. Specifically, the non-ferromagnetic metal plate can be selected from an aluminum plate or an austenitic stainless steel plate. The purpose of selecting a non-ferromagnetic metal material is to avoid interference of the end plate body 10 with the magnetic circuit of the permanent magnet motor, and at the same time, the non-ferromagnetic metal material usually has good heat conduction performance, which is conducive to heat conduction and dissipation. In the embodiment, the end plate body 10 preferably adopts an aluminum plate to meet the requirements of light weight and heat dissipation performance.

[0021] A plurality of fan blades 20 are arranged on the end face of the end plate body 10. The plurality of fan blades 20 are distributed along the circumferential direction of the end plate body 10. When the rotor rotates at a high speed, the fan blades 20 can push the surrounding air to flow, form forced convection, effectively take away the heat generated by the rotor core 30 and the permanent magnet 31, reduce the working temperature of the rotor, improve the performance of the motor, and reduce the risk of demagnetization of the permanent magnet 31 due to high temperature.

[0022] The fan blade 20 is formed by outwardly bending part of the plate body of the end plate body 10. Specifically, the fan blade 20 is formed by outwardly bending part of the plate body of the end plate body 10 through a sheet metal stamping and bending process. This integrated structure eliminates the need for secondary connection processes such as welding or riveting between the fan blade 20 and the end plate body 10, simplifies the manufacturing process, reduces production costs, and at the same time ensures the structural strength and reliability of the connection.

[0023] The fan blade 20 comprises a blade body 21 and a bending connecting part 22. The blade body 21 is the main working part of the fan blade 20 for pushing air flow. The bending connecting part 22 is connected between the blade body 21 and the end plate body 10, and is a bending transition area formed when the blade body 21 is folded from the end plate body 10. The blade body 21 is integrally connected with the end plate body 10 through the bending connecting part 22, and the three are different regions of the same plate material, having the same material and being continuous without splicing marks.

[0024] The blade body 21 is protruded relative to the end surface of the end plate body 10. In other words, the blade body 21 extends outward from the end surface of the end plate body 10 and protrudes from the surface of the end plate body 10. The surface can be regarded as the first end surface of the end plate body 10, i.e. the end surface away from the rotor core 30. Since the blade body 21 is folded from part of the plate body of the end plate body 10, a through hole 11 is formed on the end plate body 10 corresponding to the original position of the blade body 21. The through hole 11 penetrates the end plate body 10 along the thickness direction of the end plate body 10. The through hole 11 can also be used as part of the air flow channel, further promoting air flow and helping the rotor to dissipate heat.

[0025] The bending connecting part 22 is provided with a release groove 12 on each side. The release groove 12 penetrates the end plate body 10 along the thickness direction of the end plate body 10. In the sheet metal bending process, stress concentration phenomenon is easy to occur at the bending part, and if not handled, fatigue cracks may occur at this part after long-term use. The provision of the release groove 12 can effectively release the internal stress generated in the bending process of the bending connecting part 22, avoid stress concentration, and thus improve the structural reliability and service life of the connection between the fan blade 20 and the end plate body 10. At the same time, the provision of the release groove 12 can also ensure that the plate body around the bending connecting part 22 is not affected during bending, so that the end surface of the end plate body 10 (especially the second end surface, i.e. the surface attached to the rotor core 30) remains flat, facilitating the close installation of the end plate body 10 and the end surface of the rotor core 30.

[0026] In summary, the permanent magnet motor rotor end plate provided by the embodiment has the ability of active heat dissipation based on the basic functions of fixing permanent magnets 31 and facilitating dynamic balance adjustment, etc. At the same time, the blade body 21 of the fan blade 20 is integrally connected with the end plate body 10 through the bending connecting part 22, and the release grooves 12 are provided on both sides of the bending connecting part 22, effectively solving the problem of bending stress concentration and ensuring the structural strength and flatness of the product. The rotor end plate has simple structure, low manufacturing cost, light weight and good heat dissipation effect.

[0027] In an embodiment, the blade body 21 is arranged perpendicularly to the end face of the end plate body 10.

[0028] In the embodiment, the blade body 21 is folded from the bending connecting part 22, and the plate face of the blade body 21 extends in a direction perpendicular to the first end face of the end plate body 10, that is, the included angle between the plate face of the blade body 21 and the first end face of the end plate body 10 is 90 degrees.

[0029] Arranging the blade body 21 perpendicularly to the first end face of the end plate body 10 can maximize the air flow driving efficiency. When the rotor rotates, the perpendicularly arranged blade body 21 can push the surrounding air with the maximum windward area. Compared with the obliquely arranged blade, the perpendicular blade can generate stronger air flow disturbance at the same rotating speed, thereby obtaining better heat dissipation effect. In addition, the folding process can be simplified. In the sheet metal stamping and folding process, 90-degree folding is the most common and easiest to control folding angle. The mold design is simple, and the folding precision is high, which is beneficial to ensure the angle consistency of each fan blade 20 in batch production, thereby ensuring the dynamic balance performance of the rotor end plate.

[0030] In an embodiment, a notch 211 is arranged through the thickness direction of the end of the blade body 21 away from the end plate body 10.

[0031] As shown in Figure 2 In the embodiment, the end of the blade body 21 close to the end plate body 10 is a connecting end, and the free end away from the end plate body 10 is a free end. The connecting end is the end connected with the bending connecting part 22. The free end of the blade body 21 is arranged with a notch 211 through the thickness direction thereof. The notch 211 extends from the edge of the free end of the blade body 21 to the connecting end by a certain depth, and completely penetrates the blade body 21 along the thickness direction of the blade body 21.

[0032] The notch 211 can be arranged at a corner of the free end of the blade body 21. When the rotor rotates at high speed, the notch 211 can form a local air flow disturbance at the free end of the blade body 21, enhance the turbulent effect of the air, and be beneficial to improve the heat dissipation efficiency.

[0033] In an embodiment, the number of fan blades 20 is 2n, where n is a positive integer; and the fan blades 20 are uniformly distributed along the circumferential direction of the end plate body 10.

[0034] As shown in Figure 1As shown, in the embodiment, the number of the wind blades 20 is 2n, where n is a positive integer. That is, the number of the wind blades 20 is even, and can be 8, 10, 12, etc. In the embodiment, the number of the wind blades 20 is preferably 10.

[0035] The wind blades 20 are evenly distributed along the circumference of the end plate body 10. That is, the central angles between adjacent two wind blades 20 are equal. When the number of the wind blades 20 is 10, the central angle between adjacent two wind blades 20 is 36 degrees.

[0036] The number of the wind blades 20 is set to be even, so as to match the number of the magnetic poles of the rotor of the permanent magnet motor. The magnetic poles of the permanent magnet motor are usually arranged in pairs, that is, the number of the magnetic poles is an integer multiple of 2. By setting the number of the wind blades 20 to be equal to the number of the magnetic poles of the rotor, the positions of the wind blades 20 and the positions of the magnetic poles of the rotor form a regular corresponding relationship, which is beneficial to the positioning and installation between the rotor end plate and the rotor core 30.

[0037] The wind blades 20 are evenly distributed along the circumference of the end plate body 10, which can ensure that the mass of the end plate body 10 is evenly distributed along the circumference, so that the end plate body 10 itself has good initial dynamic balance performance. In the process of high-speed rotation of the rotor, the evenly distributed wind blades 20 can generate a circumferentially uniform air flow field, avoiding vibration and noise caused by uneven air flow, thereby ensuring the stability and reliability of the operation of the permanent magnet motor.

[0038] In an embodiment, the shape of the through hole 11 is matched with the profile shape of the blade body 21, and the through hole 11 is in communication with the release groove 12.

[0039] As shown in Figure 1 and Figure 2 In the embodiment, the shape of the through hole 11 is matched with the profile shape of the blade body 21. Since the blade body 21 is formed by outwardly folding the part of the end plate body 10 through the stamping and bending process, the shape of the through hole 11 left on the end plate body 10 after the folding of the blade body 21 is basically consistent with the outer peripheral profile shape of the blade body 21. For example, when the profile shape of the blade body 21 is rectangular, the shape of the through hole 11 is also rectangular corresponding thereto; when the profile shape of the blade body 21 is trapezoidal or other polygonal, the shape of the through hole 11 is also trapezoidal or corresponding polygonal matched therewith.

[0040] The shape of the through hole 11 is adapted to the contour shape of the blade body 21, which is the result of the stamping and bending process. This structural feature has the following advantages: on the one hand, the dimensional matching relationship between the blade body 21 and the through hole 11 is clear, which facilitates mold design and processing precision control; on the other hand, the material of the blade body 21 comes entirely from the plate corresponding to the position of the through hole 11, resulting in high material utilization and no stamping waste, which helps to reduce production costs.

[0041] In this embodiment, the through hole 11 is connected to the release groove 12. As described in the previous embodiment, the release groove 12 is disposed on both sides of the bent connecting portion 22, and the bent connecting portion 22 is located at the connection between the blade body 21 and the end plate body 10. Since the through hole 11 corresponds to the position of the blade body 21 before it is folded, and the release groove 12 is disposed adjacent to the bent connecting portion 22, the release groove 12 naturally extends to the edge of the through hole 11 and communicates with it, forming an integral opening structure.

[0042] The structure in which the through hole 11 is connected to the release groove 12 allows the through hole 11 and the release groove 12 to be formed in one step during the stamping process, simplifying the processing technology. At the same time, the connected opening structure facilitates the flow of air from one side of the end plate body 10 to the other side, enhancing the airflow effect when the rotor rotates and further improving the heat dissipation efficiency. In addition, the connected structure avoids the stress concentration problem that may be caused by closed holes, which helps to improve the overall structural strength of the end plate body 10.

[0043] In one embodiment, the inner circumference of the end plate body 10 is provided with a plurality of weight-reducing grooves 13, which penetrate the end plate body 10 along the thickness direction of the end plate body 10.

[0044] like Figure 1 and Figure 2 As shown, in this embodiment, the inner circumference of the end plate body 10 is recessed with a plurality of weight-reducing grooves 13. The weight-reducing grooves 13 are recessed radially outward from the inner circumference of the end plate body 10, forming a groove-shaped structure extending radially outward. The weight-reducing grooves 13 penetrate the end plate body 10 along the thickness direction, that is, the weight-reducing grooves 13 are through groove structures, and they form openings on both the first end face and the second end face of the end plate body 10.

[0045] The weight-reducing groove 13 can be formed in one step with the end plate body 10 through a stamping process, without the need for additional processing steps, and the manufacturing process is simple.

[0046] The weight-reducing groove 13 can effectively reduce the weight of the end plate body 10. By removing part of the material at the inner circumferential edge, lightweight can be achieved on the premise of ensuring the structural strength of the end plate body 10, thereby saving material cost and reducing the overall weight of the rotor assembly. At the same time, the weight-reducing groove 13 can reduce the moment of inertia of the rotor assembly. The moment of inertia is proportional to the mass and the square of the mass distribution radius. Although the removed material of the weight-reducing groove 13 is close to the rotor shaft center, the cumulative effect of multiple weight-reducing grooves 13 can still significantly reduce the moment of inertia of the rotor assembly, which is beneficial to improve the dynamic response performance of the permanent magnet motor.

[0047] In addition, the weight-reducing groove 13 can play a blocking role when performing rotor dynamic balance verification. During the dynamic balance verification process, it is usually necessary to coat dynamic balance putty on the rotor end plate to adjust the mass distribution. When the putty is filled in the weight-reducing groove 13, the groove wall of the weight-reducing groove 13 can form a block and limit for the dynamic balance putty, so that the adhesion of the dynamic balance putty is more reliable, avoiding the dynamic balance putty from falling off due to centrifugal force when the rotor is rotating at high speed, thereby ensuring the long-term stability of the rotor dynamic balance.

[0048] In the embodiment, the shape of the weight-reducing groove 13 is preferably a fan shape to provide good blocking effect.

[0049] In an embodiment, the number of weight-reducing grooves 13 is equal to the number of fan blades 20, and the weight-reducing grooves 13 are uniformly distributed along the circumference of the end plate body 10.

[0050] As Figure 1 shown, in the embodiment, the number of weight-reducing grooves 13 is equal to the number of fan blades 20. In combination with the description of the foregoing embodiment, when the number of fan blades 20 is 10, the number of weight-reducing grooves 13 is also 10.

[0051] The weight-reducing grooves 13 are uniformly distributed along the circumference of the end plate body 10, that is, the central angles between adjacent two weight-reducing grooves 13 are equal. When the number of weight-reducing grooves 13 is 10, the central angle between adjacent two weight-reducing grooves 13 is 36 degrees.

[0052] Setting the number of weight-reducing grooves 13 to be equal to the number of wind blades 20 and evenly distributed circumferentially allows the end plate body 10 to form a regular structural layout in the circumferential direction. Since the arrangement of the wind blades 20 causes changes in the mass of corresponding positions on the end plate body 10, setting an equal number of evenly distributed weight-reducing grooves 13 can create a regular mass distribution relationship with the wind blades 20, which helps ensure the dynamic balance performance of the end plate body 10 itself. Simultaneously, the evenly distributed weight-reducing grooves 13 also facilitate the flexible arrangement and reliable adhesion of the dynamic balancing putty at different phase angles, further improving the convenience and accuracy of dynamic balance adjustment.

[0053] In practical applications, the weight-reducing groove 13 can be located at the circumferential midpoint between two adjacent fan blades 20, so that the weight-reducing groove 13 and the fan blades 20 are evenly distributed alternately along the circumference. This layout makes the overall structure of the end plate body 10 more regular and the mass distribution more balanced, while also facilitating the positioning and assembly of the end plate body 10 and the rotor core 30.

[0054] In one embodiment, the end plate body 10 is further provided with a plurality of circumferentially distributed mounting through holes 14, which are used for fasteners 40 to pass through to connect the end plate body 10 to the rotor core 30.

[0055] like Figure 1 As shown, in this embodiment, the end plate body 10 is further provided with a plurality of mounting through holes 14. The mounting through holes 14 penetrate the end plate body 10 along the thickness direction of the end plate body 10, forming a channel for the fastener 40 to pass through. The plurality of mounting through holes 14 are distributed circumferentially along the end plate body 10, preferably evenly distributed circumferentially.

[0056] The mounting through hole 14 is used for fasteners 40 to pass through in order to connect the end plate body 10 to the rotor core 30. During the assembly of the rotor assembly, the end plate body 10 is placed on the axial end face of the rotor core 30, aligning the mounting through hole 14 with the corresponding pre-set through hole on the rotor core 30. Then, the fasteners 40 are passed through the mounting through hole 14 and the through hole on the rotor core 30 in sequence, thereby fastening the end plate body 10 to the rotor core 30. The fasteners 40 can be bolts, rivets, or other suitable connecting parts.

[0057] The distribution diameter of the assembly through holes 14 on the end plate body 10 is consistent with the distribution diameter of the corresponding through holes on the rotor core 30, so as to ensure that each through hole can be accurately aligned during assembly. The diameter of the assembly through holes 14 is determined according to the specifications of the selected fasteners 40, so as to ensure that the fasteners 40 can pass through smoothly and achieve reliable connection.

[0058] By providing multiple circumferentially distributed mounting through holes 14, the end plate body 10 and the rotor core 30 can be connected at multiple points using multiple fasteners 40, resulting in high connection strength and uniform stress distribution. During high-speed rotor rotation, this multi-point fastening connection effectively prevents the end plate body 10 from loosening or shifting relative to the rotor core 30, ensuring the stability and reliability of the rotor assembly operation. Furthermore, using fasteners 40 passing through the mounting through holes 14 facilitates the disassembly and replacement of the rotor end plate, which is beneficial for the maintenance of the permanent magnet motor.

[0059] In a specific implementation, the assembly through hole 14 can be set in the area between two adjacent fan blades 20, or can be flexibly arranged according to the specific structure of the rotor core 30, as long as it does not interfere with the fan blades 20, the release groove 12 and the weight reduction groove 13.

[0060] like Figure 4 and Figure 5 As shown, corresponding to the above-mentioned permanent magnet motor rotor end plate, this embodiment of the invention also provides a permanent magnet motor rotor assembly. This rotor assembly is used in a permanent magnet motor to cooperate with the stator to achieve electromagnetic energy conversion. The rotor assembly includes a rotor core 30, in which a permanent magnet 31 is disposed. Rotor end plates 32 are respectively disposed at both axial ends of the rotor core 30, and the rotor end plates 32 are permanent magnet motor rotor end plates as described in the aforementioned embodiment.

[0061] In this embodiment, the permanent magnet motor rotor assembly includes a rotor core 30. The rotor core 30 is cylindrical in shape and has a central hole for mounting the rotor shaft. The rotor core 30 is formed by stacking multiple silicon steel sheets axially, with each silicon steel sheet insulated from the others to reduce eddy current losses generated by the rotor core 30 in an alternating magnetic field.

[0062] A permanent magnet 31 is disposed within the rotor core 30. The permanent magnet 31 is embedded in a magnetic slot within the rotor core 30, forming an internal permanent magnet rotor structure. The number of permanent magnets 31 is determined according to the number of poles of the permanent magnet motor, and multiple permanent magnets 31 are evenly distributed along the circumference of the rotor core 30, forming alternating magnetic poles. The permanent magnets 31 can be made of neodymium iron boron permanent magnet material or ferrite permanent magnet material to provide the excitation magnetic field required for the operation of the permanent magnet motor.

[0063] Rotor end plates 32 are respectively provided at both axial ends of the rotor core 30. The two rotor end plates 32 are respectively fitted onto the two axial end faces of the rotor core 30, clamping the rotor core 30 and its internal permanent magnets 31 between the two rotor end plates 32. The rotor end plates 32 can restrict the axial displacement of the permanent magnets 31, preventing the permanent magnets 31 from dislodging from the rotor core 30 due to vibration or electromagnetic force during motor operation.

[0064] The rotor end plate 32 includes an annular end plate body 10, which is made of non-ferromagnetic metal plate. Multiple wind blades 20 formed by bending the plate are provided on its end face. Each wind blade 20 includes a blade body 21 and a bending connection part 22, and a through hole 11 is formed at the corresponding position. Release grooves 12 are provided on both sides of the bending connection part 22.

[0065] During the assembly of the rotor assembly, the permanent magnet 31 is first installed in the magnetic slot of the rotor core 30. Then, the two rotor end plates 32 are placed at the axial ends of the rotor core 30, so that the end plate body 10 of the rotor end plate 32 is in contact with the end face of the rotor core 30, and the rotor end plate 32 is fixedly connected to the rotor core 30 by fasteners 40. After assembly, the fan blades 20 on the rotor end plate 32 protrude in a direction away from the rotor core 30.

[0066] When the permanent magnet motor is operating, the rotor assembly rotates at high speed under the influence of the stator's rotating magnetic field. During rotation, the rotor core 30 generates heat due to hysteresis losses, and the permanent magnet 31 generates heat due to eddy current losses. Simultaneously, heat radiated from the stator side is also transferred to the rotor. The fan blades 20 on the rotor end plate 32 rotate synchronously with the rotor, driving the surrounding air to form forced convection, effectively carrying away the aforementioned heat and lowering the operating temperature of the rotor core 30 and the permanent magnet 31. This active cooling method improves the overall performance of the permanent magnet motor, reduces the risk of irreversible demagnetization of the permanent magnet 31 due to excessive temperature, and extends the service life of the permanent magnet motor.

[0067] The rotor end plate 32 can also be used for dynamic balancing of the rotor assembly. During the dynamic balancing process, counterweight materials can be added or removed at appropriate positions on the end plate body 10 of the rotor end plate 32, such as the inner wall of the weight reduction groove 13, to adjust the mass distribution of the rotor assembly, eliminate the unbalance of the rotor, and ensure that the rotor assembly runs smoothly, with low vibration and low noise when rotating at high speed.

[0068] like Figure 6As shown, corresponding to the above-described permanent magnet motor rotor assembly, this embodiment of the invention also provides a permanent magnet motor. The permanent magnet motor 50 includes a rotor assembly 53, which is the permanent magnet motor rotor assembly as described in the foregoing embodiments.

[0069] In this embodiment, the permanent magnet motor further includes a stator assembly 52 and a housing 51. The stator assembly 52 is fixedly installed inside the housing 51. The stator assembly 52 includes a stator core and stator windings wound on the stator core. The rotor assembly 53 is disposed radially inside the stator assembly and is rotatably supported on the housing by a shaft and bearings. An air gap is provided between the outer circumferential surface of the rotor assembly and the inner circumferential surface of the stator assembly to allow the rotor assembly to rotate freely relative to the stator assembly.

[0070] During the operation of the permanent magnet motor, current is applied to the stator windings to generate a rotating magnetic field, driving the permanent magnet motor rotor assembly to rotate at high speed. At this time, the rotor end plates located at both axial ends of the rotor assembly rotate synchronously with the rotor core 30. The integrated fan blades 20 on the rotor end plates agitate the air inside the motor during rotation, forming a circulating airflow. This airflow can carry away the heat generated by the rotor core 30, permanent magnets 31, and stator assembly, and dissipate it to the external environment through the casing, thereby effectively controlling the motor's temperature rise and ensuring continuous and stable operation of the motor at its rated power.

[0071] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A rotor end plate for a permanent magnet motor, characterized in that, Includes an end plate body, which is an annular non-ferromagnetic metal plate, and has multiple wind blades distributed circumferentially on its end face. The wind blade is formed by bending a portion of the end plate body outward. The wind blade includes a blade body and a bending connection portion. The blade body is integrally connected to the end plate body through the bending connection portion. The blade body protrudes from the end face of the end plate body to form a through hole on the end plate body at a position corresponding to the blade body. Release grooves are provided on both sides of the bending connection portion, and the release grooves penetrate the end plate body along the thickness direction of the end plate body.

2. The permanent magnet motor rotor end plate according to claim 1, characterized in that, The blade body is vertically disposed on the end face of the end plate body.

3. The permanent magnet motor rotor end plate according to claim 1, characterized in that, The blade body has a notch extending through it along the thickness direction at the end furthest from the end plate body.

4. The permanent magnet motor rotor end plate according to claim 1, characterized in that, The number of wind blades is 2n, where n is a positive integer; the wind blades are evenly distributed along the circumference of the end plate body.

5. The permanent magnet motor rotor end plate according to claim 1, characterized in that, The shape of the through hole is adapted to the outline shape of the blade body, and the through hole is connected to the release groove.

6. The permanent magnet motor rotor end plate according to claim 1, characterized in that, The inner circumference of the end plate body is provided with a plurality of weight-reducing grooves, which penetrate the end plate body along the thickness direction of the end plate body.

7. The permanent magnet motor rotor end plate according to claim 6, characterized in that, The number of weight-reducing grooves is equal to the number of wind blades, and the weight-reducing grooves are evenly distributed along the circumference of the end plate body.

8. The permanent magnet motor rotor end plate according to claim 1, characterized in that, The end plate body is also provided with a plurality of circumferentially distributed assembly through holes, which are used for fasteners to pass through to connect the end plate body to the rotor core.

9. A permanent magnet motor rotor assembly, characterized in that, It includes a rotor core, in which a permanent magnet is disposed, and rotor end plates are respectively disposed at both axial ends of the rotor core, wherein the rotor end plates are permanent magnet motor rotor end plates as described in any one of claims 1 to 8.

10. A permanent magnet motor, characterized in that, Includes a rotor assembly, said rotor assembly being the permanent magnet motor rotor assembly as described in claim 9.

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