Electromagnetic isolation device based on composite shielding

Abstract

The application relates to a composite shielding-based electromagnetic isolation device, the inner wall of a torus-shaped shell is provided with an axial positioning groove, the outer peripheral surface is provided with an annular positioning boss and a mounting boss, the positioning boss is formed into multi-stage embedding with a magnetic conductive material layer through a stepped groove, and the wedge-shaped pressing block bidirectional locking enhances vibration stability. The electromagnetic shielding assembly is composed of alternately stacked magnetic conductive material layers and conductive material layers, the radial thickness of the magnetic conductive layer is gradiently decreased, the composite shielding layer is arranged between a motor and a driving module group, the thickness of the magnetic conductive layer is gradiently increased along the electromagnetic propagation direction to form impedance matching. The driving module group is arranged in a circumferential deflection mode, the mounting boss establishes a directional heat dissipation path through a heat-conducting pad containing a metal mesh, and a signal connector is welded with a ferrite shielding ring outside the periphery to form a continuous magnetic flux path. The end cover heat dissipation fins and the flow guide holes are arranged in an orthogonal mode, electromagnetic shielding, heat management and mechanical stability can be effectively coordinated, and the needs of aerospace equipment for high-reliability electromagnetic isolation can be met.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic isolation of motors in aerospace equipment, and in particular to electromagnetic isolation devices based on composite shielding. Background Technology

[0002] In the field of electric propulsion and control for aerospace equipment, the traditional integrated design of motors and electronic control devices has many drawbacks. The typical layout, where the electronic control components are mounted at one end of the motor, increases installation space, manufacturing costs, and overall weight. Furthermore, with increasing integration, high-density integration easily leads to increased electromagnetic interference, particularly affecting signal transmission between the drive module group and the main control board. Although some devices incorporate filters, further optimized layouts or shielding measures are needed to reduce interference. These problems reduce the reliability of the equipment and make it difficult to meet the high-performance, lightweight, and high-stability requirements of aerospace equipment. Therefore, an innovative design is urgently needed to solve these problems.

[0003] In the field of electromagnetic equipment integration, traditional electromagnetic isolation devices generally adopt a layered shielding structure, simply superimposing conductive and magnetic layers onto the equipment shell. This type of structure suffers from drawbacks such as a single electromagnetic wave reflection path, insufficient broadband interference suppression, eddy current losses at high frequencies, and significant magnetic leakage at low frequencies. Modular components often employ an axial stacking layout, resulting in low radial space utilization, increased electromagnetic coupling between the drive unit and the motor body, and spatial interference between the heat dissipation channel and the shielding layer, affecting thermal management efficiency. During mechanical assembly, the shielding layer is fixed using adhesives or welding, which easily leads to stress concentration and interface delamination, resulting in a significant decrease in shielding effectiveness after long-term operation.

[0004] Electromagnetic isolation devices play a crucial role in power electronic equipment, suppressing electromagnetic interference and maintaining system stability. In existing technologies, shielding structures using single-layer magnetic or conductive materials struggle to simultaneously suppress broadband electromagnetic interference. While magnetic materials significantly attenuate low-frequency magnetic fields, their high-frequency shielding effectiveness is insufficient. Conductive materials, although capable of reflecting high-frequency electromagnetic waves, are prone to inducing eddy current losses. When drive modules and motor components are arranged in a compact layout, transient electromagnetic fields generated during the switching process of power devices can couple to sensitive circuits via common-mode paths. Simultaneously, the skin effect caused by high-frequency current exacerbates field distortion at the shielding layer edges. In traditional solutions, space competition between the shielding layer and heat dissipation structures leads to thermal stress concentration, and changes in interlayer contact impedance caused by mechanical vibration further reduce shielding stability. Summary of the Invention

[0005] To address the above problems, the present invention provides an electromagnetic isolation device based on composite shielding, comprising:

[0006] An annular cylindrical shell, wherein electromagnetic shielding components and a drive module group are distributed on the outer circumferential surface of the annular cylindrical shell;

[0007] The end cover is detachably connected to both ends of the annular housing, and a heat dissipation structure corresponding to the drive module group is formed on the inner side of the end cover.

[0008] An electromagnetic shielding component constitutes a ring-shaped electromagnetic barrier, comprising alternating layers of a first magnetically conductive material layer and a first conductive material layer. The first magnetically conductive material layer is fixed to the annular shell by a mechanical connection structure, and the first conductive material layer is bonded to the outer surface of the first magnetically conductive material layer by a conductive connection layer. A contact surface is formed between the first magnetically conductive material layer and the first conductive material layer.

[0009] A composite shielding layer, forming an axial electromagnetic isolation zone, is positioned between the motor assembly and the drive module assembly. It consists of alternating layers of a second magnetically conductive material and a second electrically conductive material. The thickness of the second magnetically conductive material layer varies gradient along the electromagnetic radiation direction, and its interlayer impedance varies gradient along the electromagnetic propagation path.

[0010] The drive module group includes multiple drive units distributed circumferentially, each drive unit being fixed to the outer circumferential surface of the annular shell and spaced apart from the electromagnetic shielding component;

[0011] The motor assembly is coaxially disposed within the inner cavity of the annular housing, and includes a fixedly connected stator assembly and a rotatable rotor assembly;

[0012] A signal connector penetrates the side wall of the annular cylindrical housing and connects the drive module group and the motor assembly. An electromagnetic shielding ring is provided on the outer periphery of the signal connector.

[0013] Furthermore, the annular cylindrical shell is made of high-strength aviation aluminum alloy 7075. The inner wall is provided with an axial positioning structure, and the outer circumferential surface is provided with an annular positioning structure and an installation structure. The axial positioning structure is an axial positioning groove, and the annular positioning structure is an annular positioning boss. The first magnetic material layer and the annular positioning structure form a multi-level stepped assembly relationship. The inner edge of the first magnetic material layer is provided with a stepped groove that matches the annular positioning structure. The side wall of the stepped groove is provided with anti-slip texture, and bidirectional locking is achieved by a wedge-shaped pressure block. The installation structure is an installation boss.

[0014] Furthermore, the first magnetic material layer is an annular thin sheet made of FeSiAl soft magnetic alloy, the first conductive material layer is a woven conductive cloth, the mechanical connection structure is a snap-fit ​​structure, the conductive connection layer is a conductive adhesive layer, and the contact surface is formed by a wavy pleated structure.

[0015] Furthermore, the electromagnetic shielding assembly includes at least two sets of alternating stacked structures of first magnetic material layers and first conductive material layers. The first magnetic material layer is connected to the annular shell through a mechanical connection structure and is disposed in an interface coupling structure between adjacent layers. The interface coupling structure forms a continuous wave-shaped contact surface. The interface coupling structure is a wave-shaped pleated structure with an amplitude of 0.5-1.2 mm and a wavelength of 3-5 mm. The peaks and troughs of adjacent first magnetic material layers and first conductive material layers are staggered to form multiple contact interfaces. The first conductive material layer is conformally covered to the first magnetic material layer through a first conductive connection layer. The thickness of the first magnetic material layer decreases radially. The coverage area of ​​the first conductive material layer extends at least 2 mm beyond the edge of the first magnetic material layer to form an edge-wrapping structure.

[0016] Furthermore, the drive module group includes an electrically interconnected filter module, power conversion module, and control module. The mounting axis of each drive unit in the drive module group forms an angle of 55 to 85 degrees with the radial center line of the first magnetic material layer, and the circumferential spacing angle between adjacent drive units is 30 to 60 degrees.

[0017] Furthermore, the second magnetic material layer of the composite shielding layer is a FeSiAl soft magnetic alloy layer, the thickness of which gradually increases from 0.3mm near the motor assembly to 0.8mm near the drive module assembly, and the second conductive material layer is a conductive cloth layer.

[0018] Furthermore, the heat dissipation structure includes axially extending heat dissipation fins and radially penetrating flow guide holes, and the end cover is fixed by a flange connection.

[0019] Furthermore, the electromagnetic shielding ring is made of ferrite material and welded to the second magnetic material layer of the composite shielding layer.

[0020] Furthermore, the inner wall of the axial positioning groove of the axial positioning structure forms an interference fit or a positioning pin insertion with the outer peripheral surface of the stator module.

[0021] The bottom of the axial positioning groove is provided with an anti-rotation protrusion that matches the shape of the stator module core teeth, and the axial end face of the annular positioning boss forms a stepped fit with the stepped groove of the first magnetic material layer.

[0022] The radial side of the annular positioning boss is locked to the first magnetic material layer by a wedge-shaped pressure block, and the outer surface of the wedge-shaped pressure block is covered by the edge-wrapping structure of the first conductive material layer.

[0023] The top surface of the mounting boss is rigidly connected to the base of the drive unit by bolts, and the bottom surface is thermally connected to the outer circumferential surface of the annular shell through a heat-conducting medium layer. The heat-conducting medium layer includes a metal reinforcing mesh embedded inside the mounting boss, which extends to the heat dissipation structure of the annular shell to form a thermal bridge connection.

[0024] Furthermore, the mounting structure is provided with a thermally conductive pad containing a metal reinforcing mesh, and the bottom of the drive unit of the drive module group is thermally connected to the mounting structure through the thermally conductive pad. The connection surface between the annular shell and the end cover is provided with a sealing groove filled with conductive sealant.

[0025] The beneficial effects of this invention are:

[0026] This invention effectively improves the overall performance of electromagnetic isolation devices through a composite shielding architecture and multi-physics field collaborative design. A ring-shaped electromagnetic barrier is constructed by alternating layers of magnetic and conductive materials. The gradient thickness distribution of the magnetic layers and the edge-wrapping structure of the conductive layers form an impedance-matching transition. In the low-frequency band, the high permeability of the magnetic materials attenuates magnetic field interference, while in the high-frequency band, the skin effect of the conductive materials achieves electromagnetic wave reflection. Combined with a wave-shaped contact interface, the interlayer current conduction capability is enhanced, thereby covering the shielding requirements of a wide electromagnetic spectrum and reducing high-frequency eddy current losses and edge field distortion.

[0027] To address the near-field coupling issue between the drive module assembly and the motor components, the composite shielding layer employs an alternating layering design of magnetic and conductive materials. The interlayer impedance varies gradient along the electromagnetic propagation path, forming a gradual electromagnetic attenuation mechanism. The circumferential spacing of the drive module assembly, combined with the deflection of the mounting angle, deflects the main lobe direction of electromagnetic radiation away from the sensitive area. This, along with the orthogonal distribution of axial fins and radial flow holes in the heat dissipation structure, decouples the electromagnetic wave propagation path from the heat flow direction, suppressing common-mode interference transmission while optimizing heat dissipation efficiency.

[0028] The multi-level positioning structure of the annular shell achieves three-dimensional constraint of the stator assembly through axial positioning grooves and anti-rotation protrusions. The stepped fitting and wedge-shaped pressure blocks enhance the vibration stability of the electromagnetic shielding assembly. The metal reinforcement mesh of the heat-conducting medium layer establishes a directional heat conduction path, and the elastic damping structure compensates for assembly tolerances and thermal deformation, ensuring that the contact pressure of the shielding layer remains uniformly distributed under mechanical vibration and temperature cycling conditions, maintaining the stability of the grounding circuit impedance, and improving the long-term reliability of the device in complex electromagnetic environments. Attached Figure Description

[0029] Figure 1 An exploded view of the overall structure of an electromagnetic isolation device based on composite shielding. Figure 1 ;

[0030] Figure 2 An exploded view of the overall structure of an electromagnetic isolation device based on composite shielding. Figure 2 ;

[0031] Figure 3 This is a side view of an electromagnetic isolation device based on composite shielding.

[0032] The components include: 1. Ring-shaped housing; 2. End cover; 3. Motor assembly; 4. Signal connector; 5. Drive unit; 6. Filtering module; and 7. Control module. Detailed Implementation

[0033] The following is in conjunction with the appendix Figure 1-3 The preferred embodiments of the present invention will be described in detail so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more explicit definition of the scope of protection of the present invention.

[0034] The electromagnetic isolation device based on composite shielding of the present invention is mainly used for electromagnetic isolation of motors in aerospace equipment, so as to solve the problems of large installation space, high processing cost, large overall weight and electromagnetic interference in the traditional integrated design of motors and electronic control equipment.

[0035] The axial positioning groove of the annular cylindrical housing 1 forms an interference fit with the stator assembly, and the stator core teeth and the anti-rotation protrusions on the inner wall of the positioning groove form a circumferential constraint. The stepped end face of the annular positioning boss forms an axial fit with the stepped groove of the first magnetic material layer, and the anti-slip texture on the inner edge of the magnetic material layer frictionally locks it with the serrated surface of the wedge-shaped pressure block. The wedge-shaped pressure block is distributed circumferentially, and its outer surface is covered by the extended edge of the first conductive material layer. The edge of the edge is bonded to the outer circumferential surface of the annular cylindrical housing 1 with conductive adhesive to form a continuous conductive interface. The annular cylindrical housing 1 is made of high-strength aerospace aluminum alloy 7075. This material has high strength and good heat dissipation performance, which is suitable for the requirements of lightweight and high performance in aerospace equipment. Its inner wall is provided with an axial positioning structure, specifically an axial positioning groove. The inner sidewall of the axial positioning groove forms an interference fit or a positioning pin insertion with the outer peripheral surface of the stator module, which can realize the axial positioning of the stator module within the annular cylindrical housing 1. The bottom of the axial positioning groove is provided with an anti-rotation protrusion that matches the shape of the stator module core teeth, which can prevent the stator module from rotating within the annular cylindrical housing 1. The outer peripheral surface of the annular cylindrical housing 1 is provided with an annular positioning structure and an installation structure. The annular positioning structure is an annular positioning boss. The first magnetic material layer and the annular positioning structure form a multi-level stepped assembly relationship. The inner edge of the first magnetic material layer is provided with a stepped groove that matches the annular positioning structure. The sidewall of the stepped groove is provided with anti-slip texture, and bidirectional locking is achieved by a wedge-shaped pressure block to ensure a reliable connection between the first magnetic material layer and the annular cylindrical housing 1. The installation structure is an installation boss. The installation boss is provided with a heat-conducting pad containing a metal reinforcement mesh. The bottom of the drive unit 5 of the drive module group is thermally connected to the installation structure through the heat-conducting pad, which can conduct the heat generated by the drive unit 5 to the annular cylindrical housing 1 to achieve heat dissipation.

[0036] The top surface of the mounting boss is rigidly connected to the base of drive unit 5 via bolts, with insulating sleeves fitted over the bolts for electrical isolation. A thermally conductive medium layer containing a metal reinforcing mesh is placed between the bottom surface of the mounting boss and the housing. The extended ends of the reinforcing mesh form a heat conduction path with the guide holes of the heat dissipation structure. The compression deformation of the thermally conductive medium layer absorbs the assembly tolerances between the drive module assembly and the housing while maintaining thermal resistance stability.

[0037] In the electromagnetic shielding assembly, the first magnetic material layer and the first conductive material layer are mechanically interlocked through a wavy, corrugated interface. Contact pressure at the crest enhances the conductive connection, while deformation space at the trough compensates for thermal expansion differences. The radially decreasing thickness distribution of the magnetic material layer, in conjunction with the edge-wrapping structure of the conductive material layer, achieves a radial gradient attenuation of the electromagnetic field strength. The electromagnetic shielding assembly is distributed on the outer periphery of the annular cylindrical shell 1, forming an annular electromagnetic barrier. It comprises alternating layers of a first magnetic material layer and a first conductive material layer. The first magnetic material layer is a ring-shaped thin sheet made of FeSiAl soft magnetic alloy, possessing excellent magnetic permeability; the first conductive material layer is a woven conductive cloth, possessing excellent conductivity. The first magnetic material layer is fixed to the annular cylindrical shell 1 via a mechanical connection structure, which is a snap-fit ​​structure—a simple and reliable connection method. The first conductive material layer is bonded to the outer surface of the first magnetic material layer via a conductive bonding layer, which is a conductive adhesive layer, achieving a good conductive connection between the first conductive material layer and the first magnetic material layer. A contact surface is formed between the first magnetic material layer and the first conductive material layer. This contact surface is formed by a wavy, pleated structure, which increases the contact area and improves the electromagnetic shielding effect. The electromagnetic shielding assembly includes at least two sets of alternating stacked structures of the first magnetic material layer and the first conductive material layer. An interface coupling structure between adjacent layers forms a continuous wavy contact surface. The interface coupling structure is a wavy, pleated structure with an amplitude of 0.5-1.2 mm and a wavelength of 3-5 mm. The peaks and troughs of adjacent first magnetic material layers and first conductive material layers are staggered to form multiple contact interfaces. The first conductive material layer conformally covers the surface of the first magnetic material layer through a first conductive connecting layer. The thickness of the first magnetic material layer decreases radially. The coverage area of ​​the first conductive material layer extends at least 2 mm beyond the edge of the first magnetic material layer to form an edging structure, which further improves the electromagnetic shielding effect.

[0038] The composite shielding layer features a gradient thickness of the second magnetic material layer, creating an impedance matching transition. A thinner magnetic layer near the motor improves low-frequency magnetic shielding effectiveness, while a thicker layer near the drive module enhances high-frequency eddy current losses. The second conductive material layer covers the surface of the magnetic layer and extends to the housing mounting surface, establishing an equipotential connection with the end cover 2 via a conductive sealant. The composite shielding layer is positioned between the motor assembly 3 and the drive module assembly, forming an axial electromagnetic isolation zone. It consists of alternating layers of a second magnetic material layer and a second conductive material layer. The second magnetic material layer is a FeSiAl soft magnetic alloy layer, with its thickness gradually increasing from 0.3 mm near the motor assembly 3 to 0.8 mm near the drive module assembly. This gradient optimizes the electromagnetic isolation effect based on varying electromagnetic radiation intensity. The second conductive material layer is a conductive cloth layer.

[0039] The axial fins of the heat dissipation structure are arranged parallel to the heating surface of the drive module assembly, and the radial direction of the guide holes is consistent with the natural convection airflow direction. The labyrinthine sealing groove on the flange face of the end cover 2 is filled with conductive sealant, achieving airtight protection while forming a ring-shaped grounding loop. The electromagnetic shielding ring of the signal connector 4 and the magnetic material layer of the composite shielding layer are laser-welded to form a continuous magnetic path. A uniform air gap is maintained between the inner wall of the shielding ring and the connector conductor to control distributed capacitance. The end cover 2 is detachably connected to both ends of the annular housing 1 and fixed by a flange connection. This connection method facilitates installation and disassembly, and makes it convenient for internal maintenance and repair. The inner side of the end cover 2 forms a heat dissipation structure corresponding to the drive module assembly. This heat dissipation structure includes axially extending heat dissipation fins and radially penetrating guide holes. The heat dissipation fins increase the heat dissipation area, and the guide holes allow air to circulate within the end cover 2, improving heat dissipation efficiency.

[0040] In the assembly relationship between the stator and rotor assemblies, the stator core is pressed into the axial positioning groove through an interference fit, and the rotor drive shaft forms a double-support structure with the housing through angular contact bearings. The outer ring of the bearing has an interference fit with the stepped surface of the housing, while the inner ring has a transition fit with the drive shaft. Oil reservoirs are provided on the mating surfaces to maintain the integrity of the lubricating film. A carbon fiber sheath wraps around the outer periphery of the stator core, with its fiber layup direction orthogonal to the electromagnetic field direction to suppress eddy current generation.

[0041] The input terminal of the filter module 6 in the drive module group is spatially orthogonal to the output terminal of the power module, and the control module 7 is arranged in the shielded area between adjacent drive units 5. The heat dissipation substrate of the power module and the heat-conducting medium layer of the mounting boss form surface contact, and heat is guided to the heat dissipation structure of the housing through the metal reinforcement mesh. The deflection angle of the drive units 5 causes the electromagnetic radiation main lobe direction to deviate from the sensitive element, and the spacing angle between adjacent units creates an electromagnetic wave interference cancellation effect. The drive module group includes multiple drive units 5 distributed circumferentially, and each drive unit 5 is fixed to the outer circumferential surface of the annular cylindrical housing 1 and spaced apart from the electromagnetic shielding components. The drive module group includes an electrically interconnected filter module 6, power conversion module, and control module 7. The mounting axis of each drive unit 5 in the drive module group forms an angle of 55 degrees to 85 degrees with the radial center line of the first magnetic material layer, and the circumferential spacing angle between adjacent drive units 5 is 30 degrees to 60 degrees. This layout can reduce electromagnetic interference between drive units 5.

[0042] The axial positioning groove of the annular housing 1 forms an interference fit with the outer edge of the stator assembly core. The stator teeth are embedded in the groove to prevent rotation and achieve circumferential limiting. The stepped end face of the annular positioning boss is axially fitted with the stepped groove of the first magnetic material layer. The anti-slip texture on the inner edge of the magnetic layer contacts and locks with the sawtooth surface of the wedge-shaped pressure block. The wedge-shaped pressure blocks are distributed circumferentially, and their outer surface is covered by an extended edge of conductive material layer. The edge of the edge is bonded to the housing surface with conductive adhesive to form a continuous conductive interface. The top surface of the mounting boss is fixed to the base of the drive unit 5 with high-strength bolts. The bolts are fitted with polytetrafluoroethylene insulating sleeves to isolate the potential. The bottom surface forms a heat conduction path with the housing through a thermally conductive silicone pad containing copper wire mesh. The extended end of the copper wire mesh is welded to the edge of the heat dissipation hole to establish a directional heat dissipation channel.

[0043] The first magnetic material layer in the electromagnetic shielding assembly is a FeSiAl soft magnetic alloy annular sheet with a radial thickness decreasing from the inside to the outside. Adjacent magnetic and conductive layers are mechanically interlocked through a wavy, pleated interface with an amplitude of 0.8 mm and a wavelength of 4 mm. The conductive material layer is made of silver fiber woven fabric, with its edge extending 2.5 mm beyond the edge of the magnetic layer and bonded to the conductive adhesive on the shell surface. The thickness of the second magnetic material layer in the composite shielding layer increases from 0.3 mm on the motor side to 0.8 mm on the drive module side. The surface of the conductive material layer is coated with a nano-alumina insulating coating, and its edges are equipotentially connected to the flange face of the end cover 2 through a conductive sealant. The drive module group is arranged with a 55° mounting angle and circumferential deflection, with adjacent units spaced 45° apart. The power module heat dissipation substrate and the mounting boss thermal pad form surface contact, and heat is guided to the axial heat dissipation fins through a copper wire mesh.

[0044] The stator core of motor assembly 3 is pressed into the axial positioning groove using a liquid nitrogen cooling shrinkage process. The rotor drive shaft adopts a double-support structure with angular contact bearings. The outer ring of the bearing is interference-fitted with the housing and has an oil reservoir. The carbon fiber sheath wraps the stator core in an orthogonal layup manner, with the fiber direction perpendicular to the main direction of the magnetic field. The ferrite shielding ring of signal connector 4 is connected to the magnetic material layer of the composite shielding layer by laser welding, and a uniform air gap of 0.2mm is maintained between the inner wall of the ring and the conductor. The labyrinth-type sealing groove of the end cover 2 flange is filled with silver powder conductive adhesive, with a groove depth of 1.2mm, forming a three-level tortuous path with the housing boss. The drive module group control board is arranged in the shielding area of ​​the adjacent unit, and its wiring direction is at a 55° angle to the axis of the power module. The signal line adopts a twisted pair shielding structure when passing through the electromagnetic shielding ring. Motor assembly 3 is coaxially set in the inner cavity of the annular cylindrical housing 1, including a fixedly connected stator assembly and a rotatable rotor assembly. The stator assembly is positioned with the annular cylindrical housing 1 by an axial positioning structure, and the rotor assembly can rotate under the action of the magnetic field generated by the stator assembly. The signal connector 4 penetrates the side wall of the annular housing 1 and connects the drive module assembly and the motor assembly 3. An electromagnetic shielding ring, made of ferrite material and welded to the second magnetic material layer of the composite shielding layer, is provided on its outer periphery to prevent electromagnetic interference during signal transmission. Furthermore, the connection surface between the annular housing 1 and the end cover 2 is provided with a sealing groove filled with conductive sealant to prevent electromagnetic leakage and further improve electromagnetic isolation.

[0045] In the field of electric propulsion and control of aerospace equipment, the electromagnetic isolation device of the present invention optimizes the layout of the equipment, reduces installation space and overall weight through the design of the above-mentioned structures and connections, while effectively reducing electromagnetic interference, improving the reliability of the equipment, and meeting the requirements of aerospace equipment for high performance, lightweight and high stability.

[0046] Any embodiment of the present invention can be used as an independent technical solution or in combination with other embodiments. All patents and publications mentioned in this specification represent publicly available technologies that can be used with the present invention. All patents and publications cited herein are also listed in the references as if each publication were individually referenced. The present invention can be implemented in the absence of any one or more elements, or one or more limitations, which are not specifically stated herein. The terminology and expressions used herein are descriptive methods and are not intended to be limiting, nor is there any intention to exclude any equivalent features from the terms and interpretations described herein; however, it is understood that any suitable changes or modifications can be made within the scope of the invention and the claims. It is understood that the embodiments described herein are embodiments and features in some examples, and any modifications and variations can be made by those skilled in the art based on the spirit of the description, and such modifications and variations are also considered to fall within the scope of the invention and the limitations of the independent and appended claims.

Claims

1. An electromagnetic isolation device based on composite shielding, characterized in that, include: An annular cylindrical shell, wherein electromagnetic shielding components and a drive module group are distributed on the outer circumferential surface of the annular cylindrical shell; The end cover is detachably connected to both ends of the annular housing, and a heat dissipation structure corresponding to the drive module group is formed on the inner side of the end cover. An electromagnetic shielding component constitutes a ring-shaped electromagnetic barrier, comprising alternating layers of a first magnetically conductive material layer and a first conductive material layer. The first magnetically conductive material layer is fixed to the annular shell by a mechanical connection structure, and the first conductive material layer is bonded to the outer surface of the first magnetically conductive material layer by a conductive connection layer. A contact surface is formed between the first magnetically conductive material layer and the first conductive material layer. A composite shielding layer, forming an axial electromagnetic isolation zone, is disposed between the motor assembly and the drive module assembly. It is composed of alternating layers of a second magnetic material layer and a second conductive material layer, with the thickness of the second magnetic material layer varying in a gradient along the electromagnetic radiation direction. The drive module group includes multiple drive units distributed circumferentially, each drive unit being fixed to the outer circumferential surface of the annular shell and spaced apart from the electromagnetic shielding component; The motor assembly is coaxially disposed within the inner cavity of the annular housing, and includes a fixedly connected stator assembly and a rotatable rotor assembly; A signal connector penetrates the side wall of the annular cylindrical housing and connects the drive module group and the motor assembly. An electromagnetic shielding ring is provided on the outer periphery of the signal connector.

2. The electromagnetic isolation device based on composite shielding according to claim 1, characterized in that, The annular cylindrical shell is made of high-strength aviation aluminum alloy 7075. The inner wall is provided with an axial positioning structure, and the outer circumference is provided with an annular positioning structure and an installation structure. The axial positioning structure is an axial positioning groove, and the annular positioning structure is an annular positioning boss. The first magnetic material layer and the annular positioning structure form a multi-level stepped assembly relationship. The inner edge of the first magnetic material layer is provided with a stepped groove that matches the annular positioning structure. The side wall of the stepped groove is provided with anti-slip texture, and bidirectional locking is achieved by a wedge-shaped pressure block. The installation structure is an installation boss.

3. The electromagnetic isolation device based on composite shielding according to claim 1, characterized in that, The first magnetic material layer is a ring-shaped thin sheet made of FeSiAl soft magnetic alloy, the first conductive material layer is a woven conductive cloth, the mechanical connection structure is a snap-fit ​​structure, the conductive connection layer is a conductive adhesive layer, and the contact surface is formed by a wavy pleated structure.

4. An electromagnetic isolation device based on composite shielding according to claim 1, characterized in that, The electromagnetic shielding assembly includes at least two sets of alternating stacked structures of first magnetic material layers and first conductive material layers. The first magnetic material layer is connected to the annular shell through a mechanical connection structure and is disposed in an interface coupling structure between adjacent layers. The interface coupling structure forms a continuous wave-shaped contact surface. The interface coupling structure is a wave-shaped pleated structure with an amplitude of 0.5-1.2 mm and a wavelength of 3-5 mm. The peaks and troughs of adjacent first magnetic material layers and first conductive material layers are staggered to form multiple contact interfaces. The first conductive material layer is conformally covered to the first magnetic material layer through a first conductive connection layer. The thickness of the first magnetic material layer decreases radially. The coverage area of ​​the first conductive material layer extends at least 2 mm beyond the edge of the first magnetic material layer to form an edge-wrapping structure.

5. An electromagnetic isolation device based on composite shielding according to claim 1, characterized in that, The drive module group includes an electrically interconnected filter module, a power conversion module, and a control module. The mounting axis of each drive unit in the drive module group forms an angle of 55 to 85 degrees with the radial center line of the first magnetic material layer, and the circumferential spacing angle between adjacent drive units is 30 to 60 degrees.

6. An electromagnetic isolation device based on composite shielding according to claim 1, characterized in that, The second magnetic material layer of the composite shielding layer is a FeSiAl soft magnetic alloy layer, the thickness of which gradually increases from 0.3mm near the motor assembly to 0.8mm near the drive module assembly, and the second conductive material layer is a conductive cloth layer.

7. An electromagnetic isolation device based on composite shielding according to claim 1, characterized in that, The heat dissipation structure includes axially extending heat dissipation fins and radially penetrating guide holes. The end cover is detachably connected to both ends of the annular shell and fixed by flange connection.

8. An electromagnetic isolation device based on composite shielding according to claim 1, characterized in that, The electromagnetic shielding ring is made of ferrite material and is welded to the second magnetic material layer of the composite shielding layer.

9. An electromagnetic isolation device based on composite shielding according to claim 2, characterized in that, The inner wall of the axial positioning groove of the axial positioning structure forms an interference fit or a positioning pin insertion with the outer peripheral surface of the stator assembly. The bottom of the axial positioning groove is provided with an anti-rotation protrusion that matches the shape of the iron core teeth of the stator assembly, and the axial end face of the annular positioning boss forms a stepped fit with the stepped groove of the first magnetic material layer. The radial side of the annular positioning boss is locked to the first magnetic material layer by a wedge-shaped pressure block, and the outer surface of the wedge-shaped pressure block is covered by the edge-wrapping structure of the first conductive material layer. The top surface of the mounting boss is rigidly connected to the base of the drive unit by bolts, and the bottom surface is thermally connected to the outer circumferential surface of the annular shell through a heat-conducting medium layer. The thermally conductive medium layer includes a metal reinforcing mesh embedded inside the mounting boss, which extends to the heat dissipation structure of the annular housing to form a thermal bridge connection.

10. An electromagnetic isolation device based on composite shielding according to claim 2, characterized in that, The mounting structure is equipped with a thermally conductive pad containing a metal reinforcing mesh. The bottom of the drive unit of the drive module group is thermally connected to the mounting structure through the thermally conductive pad. The connection surface between the annular shell and the end cover is equipped with a sealing groove filled with conductive sealant.

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