A high-speed disc permanent magnet motor and a preparation method of a hybrid magnetic excitation composite rotor

Abstract

The application belongs to the technical field of high-speed disc type permanent magnet motor, in order to solve the problem that the existing high-speed disc type permanent magnet motor cannot fully utilize the mechanical properties of composite magnetic material, a high-speed disc type permanent magnet motor and a preparation method of hybrid magnetic excitation composite rotor are provided, the high-speed disc type permanent magnet motor comprises a stator core, a winding and a hybrid magnetic excitation composite rotor; the hybrid magnetic excitation composite rotor is composed of a sintered permanent magnet, a composite magnetic material, a rotor support and a magnetic separation ring; the sintered permanent magnet is built-in in the rotor support, the composite magnetic material is wound around the rotor support, the composite magnetic material is combined with the sintered permanent magnet, the high tensile strength characteristics of the composite magnetic material are utilized, the outer diameter size of the sintered permanent magnet is shortened, and the outer diameter linear velocity of the sintered permanent magnet is reduced; the composite magnetic material provides a radial pre-tightening force, and the mechanical reliability of the hybrid magnetic excitation composite rotor under high-speed rotation is improved.

Description

Technical Field

[0001] This invention belongs to the technical field of high-speed disc permanent magnet motors, and particularly relates to a method for preparing a high-speed disc permanent magnet motor and a hybrid magnetic excitation composite rotor. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] High-speed disc permanent magnet motors have advantages such as high power density and compact structure, and are widely used in flywheel energy storage, aerospace and other fields. While the large diameter-to-length ratio of disc permanent magnet motors brings higher torque performance, their rotor linear velocity is also limited by the mechanical properties of the materials, making it difficult to develop them to higher speeds.

[0004] Existing technologies include a layered rotor structure for high-speed permanent magnet motors, which incorporates multiple magnetic materials such as sintered permanent magnets, ferrites, and composite magnetic materials. The rotor topology is a radial flux motor, and the disc-type permanent magnet motor has a higher torque density. Another proposed high-speed surface-mount permanent magnet motor rotor structure uses an inner carbon fiber layer, a hybrid layer, a copper shielding layer, and an outer carbon fiber layer to ensure the rotor's mechanical strength. While this provides a solution to the strength problem of radial flux permanent magnet rotors, it lacks universality for high-speed disc-type permanent magnet motor rotors and cannot fully utilize the mechanical properties of composite magnetic materials to achieve higher power and higher speed development of high-speed permanent magnet motor rotors. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention provides a method for preparing a high-speed disc permanent magnet motor and a hybrid magnetic excitation composite rotor, which reduces the outer diameter linear velocity of the sintered permanent magnet and improves the mechanical reliability of the composite rotor under high-speed rotation.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a high-speed disc-type permanent magnet motor, comprising: a stator core, windings and a hybrid magnetic excitation composite rotor;

[0008] The hybrid magnetically excited composite rotor includes a sintered permanent magnet, a magnetically shielding ring, a rotor support, and a composite magnetic material;

[0009] The rotor support and the sintered permanent magnet are symmetrically distributed on both sides of the magnetic isolation ring with the magnetic isolation ring as the central axis.

[0010] The sintered permanent magnet is placed inside the rotor support, and the composite magnetic material is wound around the surface of the rotor support.

[0011] Secondly, the present invention provides a method for preparing a hybrid magnetically excited composite rotor, applied to the above-mentioned high-speed disc permanent magnet motor, comprising:

[0012] The composite magnetic material is wound onto the surface of the rotor support and then cured.

[0013] Halbach magnetization was performed on sintered permanent magnets according to the magnetization direction, and Halbach magnetization was performed on composite magnetic materials, with the magnetization sectors marked.

[0014] The magnetized sintered permanent magnet is assembled with the rotor support and the magnetic shielding ring.

[0015] The above one or more technical solutions have the following beneficial effects:

[0016] In this invention, a high-speed disc-type permanent magnet motor includes a stator core, windings, and a hybrid magnetic excitation composite rotor. The hybrid magnetic excitation composite rotor consists of a sintered permanent magnet, a composite magnetic material, a rotor support, and a magnetic shielding ring. The sintered permanent magnet is placed inside the rotor support, and the composite magnetic material is wound around the rotor support, combining the composite magnetic material with the sintered permanent magnet. Utilizing the high tensile strength of the composite magnetic material, on the one hand, the outer diameter of the sintered permanent magnet is shortened, reducing the outer diameter linear velocity of the sintered permanent magnet; on the other hand, the composite magnetic material provides radial preload, improving the mechanical reliability of the hybrid magnetic excitation composite rotor under high-speed rotation. This solves the bottleneck problem of disc-type permanent magnet motors, where the mechanical strength reliability of the rotor is difficult to guarantee and the allowable linear velocity is low, thus limiting their development towards high speed.

[0017] In this invention, with the magnetic shielding ring as the center of symmetry, the structural components on the left and right sides of the hybrid magnetic excitation composite rotor are axially symmetrical, so as to avoid the unbalanced magnetic pull causing the hybrid magnetic excitation composite rotor to deflect or tilt.

[0018] In this invention, composite magnetic materials and sintered permanent magnets are bonded to the surface of a magnetic isolation ring, and rotor supports are bonded or mechanically installed to both sides of the magnetic isolation ring. The surface of the magnetic isolation ring is subjected to friction treatment to increase the contact friction between the magnetic materials and rotor supports and the surface of the magnetic isolation ring, thereby stabilizing the mechanical structure of the hybrid magnetic excitation composite rotor.

[0019] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0021] Figure 1This is a schematic diagram of the structure of a high-speed disc permanent magnet motor in an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the structure of the hybrid magnetic excitation assembly in an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the composite magnetic material winding process in an embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of the crimping assembly process of the sintered permanent magnet and rotor support in an embodiment of the present invention;

[0025] Figure 5 Schematic diagram of the NN-type magnetic pole assembly structure of the hybrid magnetic excitation composite rotor in an embodiment of the present invention;

[0026] Figure 6 Schematic diagram of the NS-type magnetic pole assembly structure of the hybrid magnetic excitation composite rotor in this embodiment of the invention;

[0027] Figure 7 A flowchart of the method for preparing a hybrid magnetically excited composite rotor in an embodiment of the present invention;

[0028] In the figure, 1. First stator, 2. Second stator, 3. First winding, 4. Second winding, 5. First composite magnetic material ring, 6. Second composite magnetic material ring, 7. First rotor support, 8. Second rotor support, 9. First sintered permanent magnet, 10. Second sintered permanent magnet, 11. Magnetic isolation ring, 12. Carbon fiber, 13. Magnetic powder film, 14. Metal transition piece. Detailed Implementation

[0029] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0030] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations of the present invention.

[0031] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0032] Example 1

[0033] like Figure 1As shown, this embodiment discloses a high-speed disc-type permanent magnet motor, including a stator core, windings, and a hybrid magnetic excitation composite rotor. The hybrid magnetic excitation composite rotor is composed of sintered permanent magnets, composite magnetic materials, a rotor support, and a magnetic isolation ring 11. The hybrid magnetic excitation composite rotor is symmetrically distributed on both sides with the magnetic isolation ring as the central axis. The sintered permanent magnets are placed inside the rotor support, and the composite magnetic materials are wound on the surface of the rotor support. The composite magnetic materials are layered strip magnetic materials made of magnetic powder, epoxy resin, and carbon fiber.

[0034] The stator core includes a first stator 1 and a second stator 2;

[0035] The windings include a first winding 3 and a second winding 4;

[0036] The rotor support includes a first rotor support 7 and a second rotor support 8;

[0037] The sintered permanent magnet includes a first sintered permanent magnet 9 and a second sintered permanent magnet 10.

[0038] The magnetic field direction of the high-speed disc permanent magnet motor proposed in this embodiment is along the axial direction. The magnetic circuit of the sintered permanent magnet does not pass through the composite magnetic material, and the magnetic field of the composite magnetic material does not pass through the sintered permanent magnet, which greatly improves the utilization rate of each magnetic material and the magnetic field strength of the motor can be greatly improved.

[0039] like Figure 2 As shown, the hybrid magnetic excitation assembly consists of a first composite magnetic material ring 5, a second composite magnetic material ring 6, a first rotor support 7, a second rotor support 8, a first sintered permanent magnet 9, and a second sintered permanent magnet 10.

[0040] Understandably, the composite magnetic material is wound around the surface of the rotor support to form a composite magnetic material ring.

[0041] The composite magnetic material ring is a ring made by winding composite magnetic material. Its main functions include two aspects: First, the composite magnetic material ring has the same function as the sintered permanent magnet, which is to provide a magnetic field. The composite magnetic material ring and the sintered permanent magnet work together to generate torque in the motor. Second, because the composite magnetic material contains carbon fiber, it has high tensile strength, which can protect the sintered permanent magnet inside the rotor from compressive stress and can improve the rotor linear speed.

[0042] The winding process of composite magnetic material and rotor support assembly is as follows: Figure 3 As shown.

[0043] In this embodiment, the sintered permanent magnet, rotor support, and composite magnetic material ring are symmetrically distributed on both sides of the magnetic isolation ring 11 with the magnetic isolation ring 11 as the central axis. The thickness of the structural components on both sides is the same. The sintered permanent magnet with a single pole, i.e., N pole or S pole, is installed in a segmented topology inside the rotor support.

[0044] In this embodiment, magnetic powder and epoxy resin form a magnetic powder film 13, and the composite magnetic material is formed by mixing and stacking the magnetic powder film 13 and carbon fiber 12, with the metal transition piece 14 as support to complete the cyclic winding on both sides.

[0045] This embodiment shortens the outer diameter of the sintered permanent magnet body by winding composite magnetic material around the surface of the rotor support, compared with the traditional disc motor rotor structure, while maintaining the same electromagnetic performance of the motor. It also considers the tensile strength limit of the sintered permanent magnet and increases the linear speed of the high-speed disc permanent magnet motor rotor.

[0046] In this embodiment, the sintered permanent magnet is installed into the rotor support in two ways. The first way is a cold pressing process, in which the sintered permanent magnet is inserted into the rotor support after being subjected to low-temperature treatment; for example... Figure 4 As shown, the second method is a pressing process. The sintered permanent magnets present a trapezoidal structure along the axial direction and are pasted onto the surface of the magnetic shielding ring in a distributed manner. The rotor support is internally machined. The sintered permanent magnets present a complementary trapezoidal mechanical structure with a draft angle of 1~3°.

[0047] In this embodiment, the assembly method of the sintered permanent magnet and rotor support assembly and the magnetic shielding ring 11 using cold pressing or crimping processes is divided into two types. The first method of cold pressing is to bond the sintered permanent magnet and rotor support assembly and the magnetic shielding ring 11 with resin adhesive, and to supplement the gap between the sintered permanent magnet and the magnetic shielding ring 11 with resin adhesive. The second method of crimping is to drill threaded holes between the rotor support and mechanically assemble the sintered permanent magnet and the magnetic shielding ring 11 with screws, with the drilling positions being symmetrical.

[0048] In this embodiment, both the sintered permanent magnet and the composite magnetic material are magnetized using Halbach magnetization. The sintered permanent magnet and the composite magnetic material are magnetized first, and then the rotor support is assembled and installed with the magnetic isolation ring.

[0049] The sintered permanent magnet and the composite magnetic material have the same magnetic field direction in the same sector. The magnetic field direction is alternating N and S poles along the circumference. The magnetic pole orientation on both sides of the magnetic isolation ring 11 is divided into two forms. Form one is the NN type magnetic pole assembly, such as... Figure 5As shown, specifically: the N pole position of the first sintered permanent magnet 9 on the left corresponds to the N pole position of the second sintered permanent magnet 10 on the right; the S pole position of the first sintered permanent magnet 9 on the left corresponds to the S pole position of the second sintered permanent magnet 10 on the right; Form II NS type magnetic pole assembly, as shown... Figure 6 As shown, specifically: the N pole position of the first sintered permanent magnet 9 on the left corresponds to the S pole position of the second sintered permanent magnet 10 on the right, and the S pole position of the first sintered permanent magnet 9 on the left corresponds to the N pole position of the second sintered permanent magnet 10 on the right.

[0050] Example 2

[0051] like Figure 7 As shown, the purpose of this embodiment is to provide a method for preparing a hybrid magnetically excited composite rotor, including the following steps:

[0052] S1: Install 10mm metal transition pieces 14 on both sides of the rotor support, wind the composite magnetic material onto the surface of the rotor support, cure the composite magnetic material after winding, remove the metal transition pieces 14, and remove the excess composite magnetic material by mechanical turning to obtain a structural component containing a ring of composite magnetic material and a rotor support.

[0053] Specifically, the outer diameter of the metal transition piece is consistent with the outer diameter of the rotor support. The composite magnetic material is wound from one side of the metal transition piece to the other side. At the beginning of the winding, a thin layer of carbon fiber is wound for pre-tightening treatment. The thickness of the carbon fiber is 0.5~1mm. After the composite magnetic material is wound, the carbon fiber layer is wound.

[0054] Specifically, the rotor support and the surface of the magnetic shielding ring are sanded, and the composite magnetic material is kept under tension throughout the entire process from the rotor support surface. As the number of winding layers increases, the winding tension decreases linearly.

[0055] Specifically, in the composite magnetic material, the magnetic powder film is made by mixing multi-level magnetic powder with epoxy resin. The magnetic powder gradation size is selected as 50μm, 100μm and 150μm. The magnetic powder film is laid on the surface of the carbon fiber prepreg tape in a semi-cured state. The thickness of the magnetic powder film is controlled at 0.25~0.30mm and the thickness of the carbon fiber prepreg tape is 0.07~0.1mm.

[0056] Specifically, the composite magnetic material is wound on the surface of the metal transition part for a length of 5-8 mm, and a carbon fiber layer with a thickness of 1-2 mm is reserved on the outer diameter of the composite magnetic material for mechanical turning.

[0057] Specifically, the curing temperature of the composite magnetic material is 110~120℃.

[0058] S2: Place the sintered permanent magnet inside the rotor support. Perform Halbach magnetization on the segmented sintered permanent magnet according to the magnetization direction. Perform Halbach magnetization on the composite magnetic material. Mark the magnetization sector. According to the assembly method, the first method is to place the sintered permanent magnet in a low-temperature environment, with the temperature controlled at -15-20℃, and cold press the sintered permanent magnet into the rotor support. After each structural component is at room temperature for 30-45 minutes, it is pasted or mechanically installed on both sides of the magnetic isolation ring. The second method is to paste the sintered permanent magnet onto the surface of the magnetic isolation ring in a fixed position. Apply resin glue to the surface of each reinforcing rib of the rotor support and the surface of the sintered permanent magnet, align the magnetization sector, and press it onto the sintered permanent magnet. It is then pasted or mechanically installed on both sides of the magnetic isolation ring to obtain a hybrid magnetic excitation composite rotor.

[0059] The following is a detailed description of the specific implementation of the hybrid magnetic excitation composite rotor preparation method provided in this embodiment through a concrete example:

[0060] Step 1: Wind carbon fiber onto the surface of the rotor support with a winding thickness of 0.5 mm and a single winding bandwidth of 4 mm. The axial advance speed of the spiral winding is 0.002 m / s, the circumferential advance speed is 0.12 m / s, the magnetic powder film thickness is 0.3 mm, the carbon fiber thickness is 0.1 mm, and after winding, a 1.5 mm carbon fiber layer is wound. The curing temperature is selected as 110℃.

[0061] Step 2: The composite magnetic material and rotor support assembly after curing are machined, the metal transition parts are removed, and the left and right end faces of the composite magnetic material are machined by 5mm each, and the outer diameter is machined by 0.5mm.

[0062] Step 3: Frost the left and right end faces of the magnetic shielding ring. Perform Halbach magnetization on the segmented sintered permanent magnets according to the magnetization direction. Perform Halbach magnetization on the composite magnetic material. Mark the magnetization sectors. Depending on the assembly method, the first method is to place the sintered permanent magnets in a low-temperature environment, with the temperature controlled at -20°C, and cold press the sintered permanent magnets into the rotor support. After each structural component is at room temperature for 45 minutes, it is pasted or mechanically installed onto both sides of the magnetic shielding ring. The second method is to paste the sintered permanent magnets onto the surface of the magnetic shielding ring in a fixed position. Apply resin glue to the surface of each reinforcing rib of the rotor support and the surface of the sintered permanent magnets, align the magnetization sectors, and press them onto the sintered permanent magnets. Then, paste or mechanically install them onto both sides of the magnetic shielding ring to complete the preparation of the composite rotor.

[0063] This embodiment provides a method for manufacturing a high-speed disc-type permanent magnet motor and a hybrid magnetic excitation composite rotor. The motor structure includes a stator core, windings, and a hybrid magnetic excitation composite rotor. The hybrid magnetic excitation composite rotor consists of sintered permanent magnets, composite magnetic materials, a rotor support, and a magnetic isolation ring. The composite magnetic material is a layered strip magnetic material made of magnetic powder, epoxy resin, and carbon fiber, with alternating layers along the radial direction. Linear tension is maintained during the winding process to avoid the relaxation effect caused by the strip winding. The composite magnetic material is wound on the surface of the rotor support, with metal transition pieces on both sides to assist in the winding of the composite magnetic material. This provides a margin for machining the ends and avoids unevenness of the magnetic powder film layer at the beginning and end of the winding, which could affect the circumferential magnetic field symmetry of the composite rotor. The sintered permanent magnets can be installed into the rotor support using a cold pressing or crimping process. The composite magnetic material and the sintered permanent magnets have the same magnetic field direction in the same sector. The magnetic pole distribution on both sides of the magnetic isolation ring includes two forms: N-N pole correspondence and N-S pole correspondence. Composite magnetic materials and sintered permanent magnets are bonded to the surface of the magnetic isolation ring. The rotor support is bonded or mechanically installed to both sides of the magnetic isolation ring. The surface of the magnetic isolation ring is subjected to friction treatment to increase the contact friction between the magnetic materials and the rotor support and the surface of the magnetic isolation ring, thereby stabilizing the mechanical structure of the hybrid magnetic excitation composite rotor.

[0064] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for preparing a hybrid magnetically excited composite rotor, applied to a high-speed disc-type permanent magnet motor, comprising: Stator core, windings, and hybrid magnetically excited composite rotor; The hybrid magnetically excited composite rotor includes a sintered permanent magnet, a magnetically shielding ring, a rotor support, and a composite magnetic material; the rotor support and the sintered permanent magnet are symmetrically distributed on both sides of the magnetically shielding ring with the magnetically shielding ring as the central axis; the sintered permanent magnet is placed inside the rotor support, and the composite magnetic material is wound around the surface of the rotor support; Its features include: Metal transition pieces are installed on both sides of the rotor support. Composite magnetic material is wound onto the surface of the rotor support and then cured. After curing, the metal transition pieces are removed. Halbach magnetization was performed on sintered permanent magnets according to the magnetization direction, and Halbach magnetization was performed on composite magnetic materials, with the magnetization sectors marked. The magnetized sintered permanent magnet is assembled with the rotor support and the magnetic shielding ring.

2. The method for preparing the hybrid magnetically excited composite rotor as described in claim 1, characterized in that, The magnetized sintered permanent magnet is then assembled with the rotor support and the magnetic shielding ring, specifically as follows: The magnetized sintered permanent magnet is cold-pressed into the rotor bracket, and the rotor bracket is glued or mechanically installed on the side of the magnetic shielding ring.

3. The method for preparing the hybrid magnetically excited composite rotor as described in claim 1, characterized in that, The magnetized sintered permanent magnet is then assembled with the rotor support and the magnetic shielding ring, specifically as follows: The magnetized sintered permanent magnet is attached to the surface of the magnetic isolation ring. Resin adhesive is applied to the rotor support and the surface of the sintered permanent magnet. The magnetized sectors are aligned, and the rotor support is pressed onto the sintered permanent magnet.

4. The method for preparing the hybrid magnetically excited composite rotor as described in claim 1, characterized in that, The composite magnetic material is made by mixing and laminating magnetic powder, epoxy resin and carbon fiber; a magnetic powder film is obtained by mixing multi-level magnetic powder and epoxy resin, and the magnetic powder film is laid on the surface of carbon fiber prepreg tape in a semi-cured state.

5. The method for preparing the hybrid magnetically excited composite rotor as described in claim 1, characterized in that, The sintered permanent magnet is installed onto the rotor support by a cold pressing process or a crimping process.

6. The method for preparing a hybrid magnetically excited composite rotor as described in claim 1 or 5, characterized in that, The sintered permanent magnet has a trapezoidal structure along the axial direction and is attached to the surface of the magnetic isolation ring in a distributed manner; the rotor support and the sintered permanent magnet have a complementary trapezoidal mechanical structure.

7. The method for preparing the hybrid magnetically excited composite rotor as described in claim 1, characterized in that, Both the sintered permanent magnet and the composite magnetic material are magnetized using Halbach magnetization; the sintered permanent magnet and the composite magnetic material have the same magnetic field direction in the same sector, and the magnetic field direction is alternating between the N and S poles along the circumference.

8. The method for preparing the hybrid magnetically excited composite rotor as described in claim 1, characterized in that, The N / S pole position of the first sintered permanent magnet on one side of the magnetic isolation ring corresponds to the N / S pole position of the second sintered permanent magnet on the other side of the magnetic isolation ring.

9. The method for preparing the hybrid magnetically excited composite rotor as described in claim 1, characterized in that, The N-pole position of the first sintered permanent magnet on one side of the magnetic isolation ring corresponds to the S-pole position of the second sintered permanent magnet on the other side of the magnetic isolation ring, and the S-pole position of the first sintered permanent magnet on one side of the magnetic isolation ring corresponds to the N-pole position of the second sintered permanent magnet on the other side of the magnetic isolation ring.

10. The method for preparing the hybrid magnetically excited composite rotor as described in claim 1, characterized in that, The composite magnetic material is a layered tape magnetic material made by mixing and laminating magnetic powder, epoxy resin, and carbon fiber.

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