A method of producing an electric machine housing and an electric machine housing

Abstract

The application discloses a motor shell and a production method thereof, and comprises the following steps: providing a processing base material, controlling wall thickness tolerance and forming a local thickening structure by adopting a spinning process, obtaining a spinning forming shell with a predetermined curved surface shape, then combining a composite material layer with the shell base body by adopting a laser welding process to form a gradient structure in a preset area, forming a bionic heat dissipation structure on the inner cavity surface by adopting an electrochemical machining process, forming a shell inner cavity with directional heat dissipation characteristics, processing an integrated cooling channel on the outer surface by adopting a composite process of additive manufacturing and subtractive manufacturing, constructing a three-dimensional heat dissipation network for optimization, detecting and feeding back the optimized motor shell by adopting an intelligent detection system, improving shell forming precision and material utilization by adopting a spinning process, improving heat dissipation efficiency by adopting a bionic heat dissipation structure and a three-dimensional heat dissipation network, realizing transient thermal shock buffering by cooperating with latent heat storage characteristics of a phase change material, and providing light shell heat dissipation and mechanical performance.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a method for producing a motor housing and the motor housing itself. Background Technology

[0002] As high-end equipment such as drones and new energy vehicles develop towards higher power density, the power density of motor systems has exceeded 5kW / kg. This places stringent requirements on the casing components: lightweighting (density ≤2.8g / cm³) must be achieved within a limited space. 3 High-efficiency heat dissipation (thermal conductivity > 160W / m·K) and structural load-bearing capacity are also crucial. Especially in the field of drones, every 1kg reduction in shell weight can increase flight time by 8-12 minutes, but every 10°C increase in temperature due to power increase will reduce motor efficiency by 3-5%, posing a severe challenge to the shell's thermal management capabilities.

[0003] Currently, non-cast housings primarily employ a stamping-welding combination process, which uses the plastic deformation of sheet metal to construct the basic structure. However, due to process limitations, stamping results in poor wall thickness uniformity, leading to uneven thermal resistance distribution along the heat dissipation path. Thermal deformation during welding assembly causes coaxiality deviations exceeding 0.1mm, severely impacting bearing positioning accuracy. More critically, traditional processes struggle to form irregularly shaped heat dissipation structures (such as spiral channels with a depth-to-width ratio greater than 1:4), necessitating the use of external heat sinks. This not only increases weight by 20-30% but also reduces actual heat dissipation efficiency by over 40% due to interfacial contact thermal resistance. This structural defect renders existing housings unable to meet the continuous heat dissipation requirements of motors with power densities above 5kW / kg, becoming a major bottleneck restricting the performance improvement of high-end motors.

[0004] Therefore, it is necessary to improve the existing motor housing manufacturing process to resolve the technical contradiction between insufficient mechanical strength and difficulty in forming heat dissipation structures. Summary of the Invention

[0005] The purpose of this invention is to provide a method for producing an electric motor housing and an electric motor housing, thereby solving the above-mentioned technical problems.

[0006] To achieve this objective, the present invention adopts the following technical solution: A method for manufacturing an electric motor housing includes the following steps: Step 1: Provide a processing substrate, use a spinning process to control the wall thickness tolerance and form a locally thickened structure to obtain a spinning-formed shell with a predetermined curved surface shape; Step 2: In the preset area of ​​the spun shell, the composite material layer is bonded to the shell matrix using laser welding technology. The metallurgical bonding of dissimilar material interfaces is achieved through energy control, forming a composite shell matrix with a gradient structure. Step 3: A biomimetic heat dissipation structure is formed on the inner surface of the composite shell substrate using an electrochemical processing technology, and a functional surface layer is deposited simultaneously in key areas to form an inner shell cavity with directional heat dissipation characteristics. Step 4: An integrated cooling channel is fabricated on the outer surface of the composite housing substrate using a combination of additive and subtractive manufacturing processes. The channel is then filled with phase change energy storage material to construct a three-dimensional heat dissipation network, thereby obtaining an optimized motor housing. Step 5: Use an intelligent detection system to perform online geometric measurement and thermal performance verification on the optimized motor housing, and feed the detection data back to the production system for process parameter correction.

[0007] Optionally, the provision of the processing substrate, the control of wall thickness tolerance and the formation of a locally thickened structure using a spinning process to obtain a spinning-formed shell with a predetermined curved surface shape, specifically includes the following steps: Light metal sheet is used as the processing substrate and placed in the dual spindle clamping station of the CNC spinning equipment. The material temperature is monitored by an infrared temperature measurement module and maintained in the plastic processing range of 230-270℃. Start the synchronous spinning program, and drive the light metal sheet to rotate with a preset speed difference between the upper and lower spindles. At the same time, the hydraulic forming roller performs multiple progressive spinning passes along a preset trajectory. During the spinning process, the wall thickness data is fed back in real time by a laser thickness gauge, and the spinning force parameters are dynamically adjusted to control the base wall thickness within a preset range. The first thickness thickening structure is formed by local stacking at the flange mounting part of the shell to obtain the spinning-formed shell base. The spun shell substrate is subjected to aging treatment, and held at 180-200℃ for 2-4 hours to eliminate residual stress and stabilize the curved surface shape with a predetermined axial roundness.

[0008] Optionally, the composite material layer is in a pre-consolidated state before welding, and comprises the following components: The matrix material is selected from aluminum alloy powder, accounting for 65-75% of the layer mass; The reinforcing phase, selected from carbon fiber bundles, comprises 25-35% of the layer mass. An interface modifier, wherein the interface modifier is selected from nano-titanium nitride particles, accounting for 0.5-1.5% of the mass of the layer.

[0009] Optionally, the preparation process of the composite material layer is as follows: Carbon fiber bundles are impregnated in an ethanol dispersion containing nano-titanium nitride and treated with ultrasonic vibration for 30-60 minutes to form a uniform modified coating on the carbon fiber surface, thereby forming modified carbon fibers. Modified carbon fiber and aluminum alloy powder are mixed in a certain mass ratio and a mixer is used to perform spatial gradient mixing at a preset speed to form a preform with axially distributed fibers. The preform is placed into a vacuum hot press mold and held at 480-520℃ and 50-80MPa for 20-40 minutes to completely densify the aluminum alloy powder and combine it with carbon fiber to obtain a thin composite plate. The composite sheet is laser-precision cut into irregular shapes that match the spin-formed shell, in order to obtain the corresponding composite material layer.

[0010] Optionally, the preset area of ​​the spun-formed housing specifically includes a heat dissipation critical area and a flange connection area, wherein the heat dissipation critical area is a strip-shaped area covering the stator winding projection area.

[0011] Optionally, the composite material layer is bonded to the shell substrate using laser welding in a predetermined area of ​​the spun shell. This is achieved through energy control to realize the metallurgical bonding of dissimilar material interfaces, forming a composite shell substrate with a gradient structure. Specifically, this includes the following steps: Laser texturing is performed on the surface of a preset area of ​​the spun shell, and the texturing area is formed by processing a micro-dimple array using a pulsed laser. The composite material layer is pre-installed into the texturing treatment area, and a clamping force of 0.8-1.5MPa is applied by an auxiliary positioning system, while the interface gap is monitored in real time by infrared thermal imaging. A coaxial dual-beam laser welding system is used to simultaneously output continuous wave and pulse wave, controlling the melting depth ratio between the shell matrix and the composite material layer to be 1:0.6~0.8, forming a gradient transition metallurgical bonding interface; During the welding process, Al-Si-Ti composite powder is sprayed simultaneously, and Al3Ti reinforcing phase is generated through in-situ reaction in the molten pool. This causes the hardness of the metallurgical bonding interface to transition from the first hardness gradient of the shell matrix to the second hardness of the composite layer, forming a composite shell matrix with a gradient structure.

[0012] Optionally, a biomimetic heat dissipation structure is formed on the inner surface of the composite shell substrate using an electrochemical processing technology, and a functional surface layer is deposited simultaneously in key areas to form a shell cavity with directional heat dissipation characteristics. This specifically includes the following steps: An elastic silicone mask is attached to the inner surface of the composite shell substrate, and a biomimetic scale pattern is transferred by mechanical imprinting to form a physical shielding layer with anti-electrolytic corrosion properties. The casing is immersed in a high-speed circulating electrolyte, and ultrasonic-assisted electrolytic processing is used to control the current density and form a gradient transition heat dissipation fin substrate. During the electrolytic processing, pulsed composite plating is performed simultaneously, with forward and reverse currents applied alternately to co-deposit Al2O3 nanoparticles and graphene sheets on the surface of the heat dissipation fins, forming a directional heat-conducting layer. A micro-nano composite structure is constructed on the surface of the directional thermally conductive layer by plasma activation treatment. The micro-nano composite structure includes several regularly distributed surface pores. The heat dissipation fins are smoothed using an abrasive flow polishing system to control surface roughness and form an inner cavity in the housing with directional heat dissipation characteristics.

[0013] Optionally, an integrated cooling channel is fabricated on the outer surface of the composite housing substrate using a combination of additive and subtractive manufacturing processes, and the channel is filled with a phase change energy storage material to construct a three-dimensional heat dissipation network, thereby obtaining an optimized motor housing. Specifically, this includes: Titanium alloy powder was deposited on the outer surface of the composite shell substrate by selective laser melting to construct a substrate channel with a preset width and a depth-to-width ratio of 1:4. Ultra-high pressure water jet is used to perform subtractive processing on the sidewalls of the substrate channel to remove slag and control surface roughness, forming a precision flow channel with a preset cross-sectional tolerance; A second-thickness porous ceramic layer is generated by plasma electrolytic oxidation treatment on the inner wall of the precision flow channel, wherein the micropore size distribution of the porous ceramic layer is 50~150nm. The composite phase change material is heated to a molten state, and the porous ceramic layer is filled by a vacuum impregnation process. After cooling and solidification, the phase change enthalpy value is made greater than the preset enthalpy value. Laser micro-cladding technology is used to clad a Ni-based alloy sealing layer at the opening of the precision flow channel to form an airtight closed channel, thereby constructing a three-dimensional heat dissipation network. The equivalent thermal conductivity of a three-dimensional heat dissipation network is detected online using the transient planar heat source method, and the heat dissipation levels of the motor housing are classified and sorted.

[0014] Optionally, the composite phase change material is a composite material of paraffin / expanded graphite / nano Cu, and the mass ratio of paraffin, expanded graphite and nano Cu is 6:3:1.

[0015] The present invention also provides a motor housing, which is manufactured using the motor housing production method described above, characterized in that the motor housing specifically comprises: The shell base is a spin-formed shell with a predetermined curved shape, formed by a spinning process; Gradient composite layer, formed by bonding composite material layer to shell matrix through laser welding; The housing cavity has directional heat dissipation features; Integrated cooling channels are closed flow channels processed on the outer surface of the composite shell substrate using a combination of additive and subtractive manufacturing processes.

[0016] Compared with existing technologies, this invention has the following advantages: First, a shell substrate with precise wall thickness control is prepared by spin forming. Then, a gradient material composite structure is achieved by laser welding in key areas. Next, biomimetic heat dissipation features are formed in the inner cavity and a functional layer is deposited by electrochemical processing. Furthermore, an integrated cooling channel is constructed on the outer surface by additive-subtractive composite process and filled with phase change material. Finally, closed-loop quality control is achieved by intelligent detection system, forming a lightweight motor shell with both high heat dissipation efficiency and structural strength. This solution improves the shell forming accuracy and material utilization rate through spin forming, achieves high-strength bonding of dissimilar materials by laser welding, enhances heat dissipation efficiency by forming a biomimetic heat dissipation structure by electrochemical processing, and improves heat dissipation efficiency by constructing a three-dimensional heat dissipation network by additive-subtractive composite process. Combined with the latent heat storage characteristics of phase change material, transient thermal shock buffering is achieved, providing a production process for a lightweight motor shell that balances heat dissipation and mechanical performance. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] The structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0019] Figure 1 This is one of the flowcharts illustrating the manufacturing method of the motor housing in this embodiment. Figure 2 This is the second schematic diagram of the production method of the motor housing in this embodiment one; Figure 3 This is the third flowchart illustrating the production method of the motor housing in this embodiment. Detailed Implementation

[0020] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0021] In the description of this invention, it should be understood that the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component positioned centrally in the connection.

[0022] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0023] Example 1: Combination Figures 1 to 3 As shown, this embodiment of the invention provides a method for manufacturing a motor housing, comprising the following steps: Step 1: Provide a processing substrate, use a spinning process to control the wall thickness tolerance and form a locally thickened structure to obtain a spinning-formed shell with a predetermined curved surface shape; Spinning is a process that uses spinning to plastically deform lightweight metal sheets, utilizing a rotational pressure gradient to achieve directional material flow. This process controls wall thickness uniformity through multi-pass progressive forming, while simultaneously creating localized thickening structures in load-bearing areas such as flanges. This ensures both overall lightweighting of the shell and enhanced load-bearing capacity in critical areas. The continuous curved surface of the spinning process provides a geometrically accurate foundation for subsequent composite processes, avoiding the stress concentration problems at joints inherent in traditional stamping techniques.

[0024] Step 2: In the preset area of ​​the spun shell, the composite material layer is bonded to the shell substrate using laser welding technology. The metallurgical bonding of dissimilar material interfaces is achieved through energy control, forming a composite shell substrate with a gradient structure. This technology employs adjustable-energy laser welding to achieve metallurgical bonding of dissimilar materials within a pre-defined area. By precisely controlling the heat input and treatment time, a gradient transition interface is formed between the aluminum alloy matrix and the composite material layer, effectively mitigating the difference in thermal expansion coefficients between the different materials. This process overcomes the bottleneck of heat-affected zone embrittlement in traditional welding methods, achieving synergistic optimization of structural strength and functional properties.

[0025] Step 3: A biomimetic heat dissipation structure is formed on the inner surface of the composite shell substrate using an electrochemical processing technology, and a functional surface layer is deposited simultaneously in key areas to form an inner shell cavity with directional heat dissipation characteristics. Based on the principle of electrochemical etching, a biomimetic scale structure is formed by selectively removing material from the inner cavity of the shell. Simultaneously, an electrodeposition process is performed to construct a functional coating on the heat dissipation surface. Through a combination of microstructure design and material modification, the surface thermal radiation efficiency and airflow guidance effect are enhanced. This method solves the problem of machining complex internal cavity structures, achieving a balance between heat dissipation performance and structural integrity.

[0026] Step 4: An integrated cooling channel is fabricated on the outer surface of the composite housing substrate using a combination of additive and subtractive manufacturing processes. The channel is then filled with phase change energy storage material to construct a three-dimensional heat dissipation network, thereby obtaining an optimized motor housing. By combining the spatial free-form advantages of additive manufacturing with the precision machining capabilities of subtractive manufacturing, an integrated cooling channel is constructed on the outer surface of the shell. The phase change energy storage material filled within the channel absorbs transient thermal shocks through solid-liquid phase change, and its porous carrier structure design enhances thermal cycle stability. This three-dimensional heat dissipation system overcomes the volume limitations of traditional heat dissipation solutions, achieving an organic combination of active and passive heat dissipation.

[0027] Step 5: Use an intelligent detection system to perform online geometric measurement and thermal performance verification on the optimized motor housing, and feed the detection data back to the production system for process parameter correction.

[0028] An online inspection system employing multi-sensor fusion is used to simultaneously acquire shell geometric parameters and thermodynamic performance data. A mapping model between process parameters and performance indicators is established using machine learning algorithms, providing real-time feedback to adjust production parameters. This closed-loop quality control mechanism significantly improves the consistency of the manufacturing process, providing technical assurance for the repeatable manufacturing of complex components.

[0029] The working principle of this invention is as follows: First, a shell substrate with precise wall thickness control is prepared by spin forming. Then, a gradient material composite structure is achieved in key areas using laser welding. Next, biomimetic heat dissipation features are formed in the inner cavity and a functional layer is deposited through electrochemical processing. Furthermore, an integrated cooling channel is constructed on the outer surface through an additive-subtractive composite process and filled with phase change material. Finally, a closed-loop quality control is achieved through an intelligent detection system, forming a lightweight motor shell that combines high heat dissipation efficiency and structural strength. This solution improves the shell forming accuracy and material utilization through spin forming, achieves high-strength bonding of dissimilar materials through laser welding, enhances heat dissipation efficiency through the biomimetic heat dissipation structure formed by electrochemical processing, and improves heat dissipation efficiency through the three-dimensional heat dissipation network constructed by the additive-subtractive composite process. Combined with the latent heat storage characteristics of phase change material, it achieves transient thermal shock buffering, providing a production process for a lightweight motor shell that balances heat dissipation and mechanical performance.

[0030] In this embodiment, step S1 specifically includes the following steps: S11 uses light metal sheet as the processing substrate and places it in the dual spindle clamping station of the CNC spinning equipment. The material temperature is monitored by an infrared temperature measurement module and maintained in the plastic processing range of 230-270℃. Lightweight metal sheets are clamped in a dual-spindle spinning machine, and the processing temperature is controlled in real time via infrared thermography. The selected temperature range of 230-270℃ balances the material's plastic deformation capacity and microstructural stability, avoiding both work hardening caused by low temperatures and grain coarsening caused by high temperatures. The dual-spindle clamping design ensures radial constraint of the sheet during the spinning process, laying the foundation for subsequent uniform deformation.

[0031] S12, start the synchronous spinning program. The upper and lower spindles drive the light metal sheet to rotate with a preset speed difference. At the same time, the hydraulic forming roller performs multiple progressive spinning processes along a preset trajectory. The upper and lower spindles are set to rotate at different speeds, driving the sheet metal to rotate. Combined with the progressive multi-pass pressing of the hydraulic forming rollers, controllable material flow is achieved. The shear stress field generated by the speed difference can refine the grain structure, while the multi-pass forming strategy (such as coarse spinning followed by fine spinning) effectively disperses deformation stress, significantly reducing the risk of wrinkling. Preset trajectory programming makes it possible to form complex curved surfaces.

[0032] S13, during the spinning process, the wall thickness data is fed back in real time by a laser thickness gauge, and the spinning force parameters are dynamically adjusted to control the base wall thickness within the preset range. The first thickness thickening structure is formed by local stacking at the flange mounting part of the shell to obtain the spinning-formed shell base. A closed-loop control system, comprised of online monitoring by a laser thickness gauge and dynamic adjustment of spinning pressure, ensures uniform wall thickness. For the localized overlapping design of the flange, increased material buildup enhances the load-bearing capacity of the mounting surface while avoiding overall weight gain. This process overcomes the limitations of traditional spinning for uniform thinning, achieving a function-oriented gradient wall thickness distribution.

[0033] S14. The spun shell substrate is aged by holding it at 180-200℃ for 2-4 hours to eliminate residual stress and stabilize the curved surface shape with a predetermined axial roundness.

[0034] Aging treatment at 180-200℃ promotes uniform distribution of precipitated phases and eliminates residual stress generated by spinning. A holding time of 2-4 hours balances microstructure stabilization with production efficiency, ensuring the shell's axial roundness meets precision assembly requirements. This process effectively suppresses dimensional springback during subsequent processing, guaranteeing the long-term geometric accuracy of the shell.

[0035] In this embodiment, it is further explained that the composite material layer is in a pre-consolidated state before welding, and it includes the following components: The matrix material is aluminum alloy powder, accounting for 65-75% of the layer mass; the reinforcing phase is carbon fiber bundle, accounting for 25-35% of the layer mass; and the interface modifier is nano-titanium nitride particles, accounting for 0.5-1.5% of the layer mass.

[0036] The composite material layer employs a synergistic design of an aluminum alloy matrix (65-75%) and a carbon fiber reinforcing phase (25-35%), supplemented by a nano-titanium nitride interface modifier (0.5-1.5%). The aluminum alloy matrix provides basic thermal conductivity and formability, the carbon fiber enhances axial mechanical properties, and the nano-titanium nitride particles improve the fiber-matrix interface bonding through the pinning effect, while simultaneously inhibiting the aluminum-carbon reaction at high temperatures, forming a lightweight, highly thermally conductive composite system.

[0037] The composite material layer is in a pre-consolidated state before welding, with fiber axial orientation >80%, layer thickness of 0.8±0.05mm, and surface roughness Ra≤1.6μm.

[0038] In this embodiment, the specific process for preparing the composite material layer is as follows: S201 involves impregnating carbon fiber bundles in an ethanol dispersion containing nano-titanium nitride and then treating them with ultrasonic vibration for 30-60 minutes to form a uniform modified coating on the carbon fiber surface, thereby forming modified carbon fibers. A nano-titanium nitride coating is uniformly applied to the surface of carbon fibers using an ultrasonic-assisted impregnation process. The low surface tension of the ethanol dispersion facilitates the penetration of nanoparticles into the interfiber bundles, and 30-60 minutes of ultrasonic treatment ensures high coating coverage. The modified layer improves the wettability between the fiber and the aluminum matrix and reduces interfacial thermal resistance.

[0039] S202 involves mixing modified carbon fiber and aluminum alloy powder in a certain mass ratio, and then using a mixer at a preset speed to perform spatial gradient mixing to form a preform with axially distributed fibers. A three-dimensional mixing strategy is employed, utilizing the coupling effect of centrifugal force and vibration fields to achieve axial orientation distribution of carbon fibers. A preset rotation speed (e.g., 45-60 rpm) controls the uniformity of fiber dispersion, preventing agglomeration damage. Spatial gradient mixing increases the fiber volume fraction along the thickness direction (25%→35%), matching the stress distribution of the shell.

[0040] S203 involves loading the preform into a vacuum hot press mold and holding it under pressure at 480-520℃ and 50-80MPa for 20-40 minutes to completely densify the aluminum alloy powder and combine it with carbon fiber to obtain a thin composite sheet. The hot-pressing temperature range of 480-520℃ is lower than the melting point of aluminum (660℃), avoiding thermal damage to the fibers, while the plastic flow of aluminum powder fills the gaps between the fibers. A pressure of 50-80MPa ensures density, and a holding time of 20-40 minutes balances diffusion bonding efficiency with energy consumption costs.

[0041] S204 involves laser precision cutting of the composite sheet to create an irregular profile that matches the spun shell, thereby obtaining the corresponding composite material layer.

[0042] Laser precision cutting utilizes the non-contact processing characteristics of high-energy beams to avoid interlayer delamination caused by mechanical stress. The cutting path is programmed to match the shell surface parameters (such as radius of curvature R≥5mm), and the heat-affected zone and contour matching accuracy of the cut are controlled, providing a precise alignment reference for subsequent laser welding.

[0043] As a preferred embodiment, the preset area of ​​the spun shell specifically includes a heat dissipation key area and a flange connection area, wherein the heat dissipation key area is a strip-shaped area covering the stator winding projection area.

[0044] By focusing the pre-defined area of ​​the spun housing on the critical heat dissipation area (stator winding projection area) and the flange connection area, "precise functional enhancement" is achieved through localized reinforcement design. The strip-shaped layout of the critical heat dissipation area matches the heat flux density distribution of the motor, ensuring an efficient heat conduction path; the annular reinforcement design of the flange connection area addresses the problem of assembly stress concentration, improving connection reliability while reducing weight, forming a lightweight solution of "thermal-mechanical synergistic optimization".

[0045] In this embodiment, step S2 specifically includes the following steps: S21, Laser texturing is performed on the surface of the preset area of ​​the spin-formed shell, and the texturing area is formed by processing a micro-dimple array with a pulsed laser. Laser processing is employed to create a micro-dimple array (50-80 μm in diameter, 20-40 μm in depth). Short pulse widths reduce heat input, preventing thermal damage to the substrate while precisely controlling the dimple morphology. A moderate energy density, near the ablation threshold, effectively removes the oxide layer while inhibiting excessive molten pool expansion. The micro-dimple array design enhances interfacial bonding strength through a mechanical interlocking effect, and its size and distribution match the subsequent welding penetration requirements, providing a morphological basis for a gradient transition interface.

[0046] S22, the composite material layer is pre-installed into the roughened treatment area, and a clamping force of 0.8-1.5MPa is applied by an auxiliary positioning system, while the interface gap is monitored in real time by infrared thermal imaging. A dynamic clamping force of 0.8-1.5 MPa is applied, combined with real-time monitoring of the interface gap using infrared thermal imaging. The lower limit of the clamping force ensures a tight fit between the material layers, while the upper limit prevents deformation of the thin-walled shell. Infrared thermal imaging detects the interface contact state non-contactly through temperature field differences, significantly improving efficiency and eliminating the risk of scratches compared to traditional contact detection. Dynamic pressure adjustment adapts to changes in the curvature of the shell surface, ensuring uniform bonding across complex surfaces.

[0047] S23 employs a coaxial dual-beam laser welding system to synchronously output continuous and pulsed waves, controlling the melting depth ratio between the shell matrix and the composite material layer to be 1:0.6~0.8, forming a gradient transition metallurgical bonding interface; The combined effect of continuous wave (4kW) and pulsed wave (peak 8kW) is employed to control the weld penetration ratio to 1:0.6-0.8. The continuous wave achieves deep penetration welding of the matrix, ensuring structural strength; the high-frequency modulation of the pulsed wave suppresses overheating at the composite material interface, reducing thermal damage to the carbon fibers. The weld penetration ratio design creates a gentle hardness gradient in the bonding zone (matrix → composite layer), alleviating stress concentration at the interface caused by thermal expansion mismatch between dissimilar materials, while the narrow heat-affected zone ensures controllable welding deformation.

[0048] S24, during the welding process, Al-Si-Ti composite powder is sprayed simultaneously, and Al3Ti reinforcing phase is generated through in-situ reaction in the molten pool. This causes the hardness of the metallurgical bonding interface to transition from the first hardness gradient of the shell matrix to the second hardness of the composite layer, forming a composite shell matrix with a gradient structure.

[0049] Al-Si-Ti composite powder (particle size 10-25 μm, feed rate 15 g / min) is sprayed to induce an in-situ reaction in the molten pool, generating nano-Al3Ti phase. Particle size control ensures complete melting and uniform reaction, while the feed rate matches the dynamic volume changes of the molten pool. The high-temperature stability and dispersed distribution characteristics of the Al3Ti phase significantly improve the high-temperature strength of the interface. Its gradient distribution design (volume fraction 12-15%) allows for a smooth transition of hardness from the matrix to the composite layer, inhibiting fatigue crack initiation and extending the service life of the welded joint.

[0050] In this embodiment, step S3 specifically includes the following steps: S31, an elastic silicone mask is attached to the inner surface of the composite shell substrate, and a biomimetic scale pattern is transferred by mechanical imprinting to form a physical shielding layer with anti-electrolytic corrosion properties. A biomimetic scale pattern is transferred onto the inner cavity of the housing using a flexible silicone mask via mechanical imprinting (pressure 0.3-0.5 MPa). The low hardness of silicone allows it to fit tightly against the curved inner wall, avoiding pattern distortion caused by deformation mismatch in traditional rigid masks. The moderate imprinting pressure ensures pattern transfer accuracy while preventing plastic deformation of the substrate. An electrolytic corrosion-resistant masking layer is achieved through the dense cross-linked structure of the silicone, providing precise boundary control for subsequent selective etching while significantly reducing process costs.

[0051] S32 involves immersing the casing in a high-speed circulating electrolyte (20wt% NaNO3 + 2wt% potassium sodium tartrate), using ultrasonic-assisted electrolytic processing to control the current density and form a gradient transition heat dissipation fin substrate. An electrolyte containing 20 wt% NaNO3 and 2 wt% sodium potassium tartrate is used. NaNO3 provides a high etching rate, while sodium potassium tartrate inhibits intergranular corrosion by complexing aluminum ions. High-speed circulation maintains a uniform concentration of active components in the electrolyte, preventing ion depletion in the processing area. Ultrasonic-assisted cavitation (28 kHz, 15 μm amplitude) breaks up the passivation film and removes etching debris, improving the uniformity of etching depth. The radius of the fin root fillet is controlled to R0.05-0.1 mm. This combination of parameters ensures processing efficiency while forming a clean substrate with a surface roughness Ra≤3.2 μm, providing an ideal interface for subsequent functional coatings.

[0052] S33, during the electrolytic processing, pulse composite plating is performed simultaneously, with alternating application of forward and reverse currents, to co-deposit Al2O3 nanoparticles and graphene sheets on the surface of the heat dissipation fins to form a directional heat conduction layer. Alternating forward current (10 A / dm², 50 ms) and reverse current (3 A / dm², 20 ms) drive the co-deposition of Al₂O₃ nanoparticles (80 nm) and graphene sheets (2-5 nm) during the forward phase, while the reverse phase removes loosely bonded particles. The high hardness of Al₂O₃ (HV≥1500) enhances surface wear resistance, and the layered structure of graphene forms a directional thermal conductivity path. The pulse cycle is matched to the particle settling kinetics, the coating porosity is controlled at 5-8%, and the surface roughness Ra≤1.6 μm, meeting the interface requirements for subsequent plasma activation and simultaneously improving in-plane thermal conductivity.

[0053] S34 uses plasma activation treatment to construct a micro-nano composite structure on the surface of a directional thermally conductive layer. The micro-nano composite structure includes several regularly distributed surface pores. Argon-hydrogen mixed gas (volume ratio 9:1) with a power density of 2W / cm³ was used. 2 Plasma activation treatment reduces surface oxides with hydrogen free radicals, while argon ion bombardment forms micron-sized pores. This balances structure formation efficiency with the risk of thermal damage, and the substrate temperature is kept below 150℃ to prevent coating peeling. The micro-nano composite structure increases the effective heat dissipation area and improves the surface emissivity, while the roughness Ra is increased to 2.5-3.0 μm to enhance airflow disturbance, thus comprehensively improving convective and radiative heat dissipation efficiency.

[0054] The S35 uses an abrasive flow polishing system to smooth the heat dissipation fins, control the surface roughness, and form a housing cavity with directional heat dissipation characteristics.

[0055] A flexible abrasive flow system using SiO2 abrasives at a flow rate of 30 L / min was employed. The hardness and particle size of the abrasives were matched to the gaps between the heat dissipation fins. Microburrs remaining from electrolysis and plating processes were removed through fluid shearing force. After polishing, the surface roughness was reduced to Ra≤0.8μm, reducing airflow resistance while retaining the heat dissipation enhancement characteristics of the micro / nano structure, thus achieving a balance between heat dissipation efficiency and hydrodynamic performance.

[0056] In this embodiment, step S4 specifically includes: S41, titanium alloy powder is deposited on the outer surface of the composite shell substrate by selective laser melting to construct a substrate channel with a preset width and a depth-to-width ratio of 1:4; The matrix channels are formed using titanium alloy powder via selective laser melting (SLM). Synergistic control of laser power (400-600W) and scanning speed (800-1200mm / s) ensures precise forming of the channels with a depth-to-width ratio of 1:4, while avoiding deformation caused by heat accumulation. The high specific strength of titanium alloy achieves lightweighting while maintaining the structural strength of the flow channel, and its corrosion resistance meets the requirements for long-term contact with the cooling medium, providing a geometric benchmark for subsequent functional modifications.

[0057] S42 uses ultra-high pressure water jet to perform subtractive processing on the sidewalls of the substrate channel, removes slag and controls surface roughness, forming a precision flow channel with a preset cross-sectional tolerance; The channel sidewalls are precision machined using a 380MPa ultra-high pressure water jet combined with abrasive. The high pressure effectively removes slag, and the abrasive particle size matches the target surface roughness. The non-contact machining characteristic avoids mechanical stress damage to the thin-walled flow channel, and the micro-pit structure formed by the abrasive impact enhances the adhesion of subsequent coatings. Closed-loop pressure control ensures that the flow channel cross-sectional tolerance reaches ±0.05mm, significantly improving the uniformity of coolant flow.

[0058] S43, a second-thickness porous ceramic layer is generated on the inner wall of the precision flow channel by plasma electrolytic oxidation treatment, wherein the micropore size distribution of the porous ceramic layer is 50~150nm; Plasma electrolytic oxidation was performed under a 450V, 1000Hz AC electric field, with the electrolyte containing phosphates and silicates. High-frequency pulses suppressed arc discharge, and the electrolyte composition regulated the porosity of the ceramic layer, with a pore size distribution of 50-150nm. The porous structure provided a high specific surface area carrier for the phase change material, the nanoscale pores limited the volume expansion of the phase change, the hardness of the ceramic layer improved wear resistance, and phosphate doping enhanced the interlayer bonding force.

[0059] S44, the composite phase change material is heated to a molten state, and a porous ceramic layer is filled by vacuum impregnation process. After cooling and solidification, the phase change enthalpy value is made greater than the preset enthalpy value. A vacuum environment eliminates pore gases, a temperature of 70℃ ensures material fluidity, expanded graphite forms a three-dimensional thermally conductive network and suppresses leakage, and nano-Cu enhances thermal conductivity. The phase transition enthalpy after curing is ≥180J / g, meeting transient heat dissipation requirements.

[0060] S45 uses laser micro-cladding technology to clad a Ni-based alloy sealing layer at the opening of a precision flow channel, forming an airtight closed channel to construct a three-dimensional heat dissipation network. The process employs an 800W laser with a 0.3mm spot diameter to clad a Ni-based alloy (melting point 1450℃). The narrow spot size and high power density enable rapid, localized melting. The high-temperature strength and corrosion resistance of the Ni-based alloy ensure the integrity of the sealing layer under the influence of coolant. Rapid laser solidification forms a fine-grained structure, achieving the required airtightness.

[0061] S46 uses the transient planar heat source method to detect the equivalent thermal conductivity of the three-dimensional heat dissipation network online, and classifies and sorts the heat dissipation levels of the motor housing.

[0062] The equivalent thermal conductivity is detected online using a transient planar heat source method (50W test power, 100Hz sampling frequency). The heat source power is matched to the thermal capacity characteristics of the casing, and high-frequency sampling captures the transient response curve. Based on the thermal conductivity classification, a matching basis is provided for motor assembly. At the same time, the test data is fed back in real time to optimize process parameters and improve batch consistency.

[0063] In this embodiment, it is further explained that the composite phase change material is a composite material of paraffin wax / expanded graphite / nano Cu, and the mass ratio of paraffin wax, expanded graphite and nano Cu is 6:3:1.

[0064] It should be noted that paraffin, as the main body of phase change energy storage, provides high latent heat and a wide phase change temperature range; expanded graphite is used to construct a three-dimensional porous framework, improve the thermal conductivity of the material and suppress leakage in the molten state; nano-Cu is dispersed in the paraffin-graphite system, which enhances the thermal diffusion capability through its high thermal conductivity.

[0065] This formula balances thermal density, structural stability, and cost. The trace addition of nano-Cu improves thermal conductivity while avoiding phase separation problems caused by excessive addition.

[0066] Example 2: The present invention also provides a motor housing, which is manufactured using the motor housing production method of Embodiment 1, characterized in that the motor housing specifically comprises: The shell substrate is a spin-formed shell with a predetermined curved shape, formed by a spinning process.

[0067] The gradient composite layer is formed by bonding the composite material layer to the shell matrix through laser welding.

[0068] The housing cavity has directional heat dissipation features.

[0069] Integrated cooling channels are closed flow channels processed on the outer surface of the composite shell substrate using a combination of additive and subtractive manufacturing processes.

[0070] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for producing an electric motor housing, characterized in that, Includes the following steps: Step 1: Provide a processing substrate, use a spinning process to control the wall thickness tolerance and form a locally thickened structure to obtain a spinning-formed shell with a predetermined curved surface shape; Step 2: In the preset area of ​​the spun shell, the composite material layer is combined with the shell matrix using laser welding technology. The metallurgical bonding of the dissimilar material interface is achieved through energy control, forming a composite shell matrix with a gradient structure. The preset area of ​​the spun shell specifically includes a heat dissipation key area and a flange connection area, wherein the heat dissipation key area is a strip-shaped area covering the stator winding projection area. Step 3: A biomimetic heat dissipation structure is formed on the inner cavity surface of the composite shell substrate using an electrochemical processing technology, and a functional surface layer is deposited simultaneously in key areas to form an inner cavity with directional heat dissipation characteristics; wherein, the simultaneous deposition of the functional surface layer in key areas specifically involves: co-depositing Al2O3 nanoparticles and graphene sheets on the surface of the heat dissipation fins of the biomimetic heat dissipation structure to form a directional heat conduction layer. Step 4: An integrated cooling channel is fabricated on the outer surface of the composite shell substrate using a combination of additive and subtractive manufacturing processes. The channel is then filled with a composite phase change material to construct a three-dimensional heat dissipation network, thus obtaining the motor shell. The composite phase change material is a composite material of paraffin wax, expanded graphite, and nano-Cu, with a mass ratio of 6:3:

1. Step 5: Use an intelligent detection system to perform online geometric measurement and thermal performance verification on the motor housing, and feed the detection data back to the production system for process parameter correction.

2. The method for producing a motor housing according to claim 1, characterized in that, The provision of the processing substrate, the control of wall thickness tolerance and the formation of a locally thickened structure using a spinning process to obtain a spinning-formed shell with a predetermined curved surface shape, specifically includes the following steps: Light metal sheet is used as the processing substrate and placed in the dual spindle clamping station of the CNC spinning equipment. The material temperature is monitored by an infrared temperature measurement module and maintained in the plastic processing range of 230-270℃. Start the synchronous spinning program, and drive the light metal sheet to rotate with a preset speed difference between the upper and lower spindles. At the same time, the hydraulic forming roller performs multiple progressive spinning passes along a preset trajectory. During the spinning process, the wall thickness data is fed back in real time by a laser thickness gauge, and the spinning force parameters are dynamically adjusted to control the base wall thickness within a preset range. The first thickness thickening structure is formed by local stacking at the flange mounting part of the shell to obtain the spinning-formed shell base. The spun shell substrate is subjected to aging treatment, and held at 180-200℃ for 2-4 hours to eliminate residual stress and stabilize the curved surface shape with a predetermined axial roundness.

3. The method for producing a motor housing according to claim 1, characterized in that, The composite material layer is in a pre-consolidated state before welding. Includes the following ingredients: The matrix material is selected from aluminum alloy powder, accounting for 65-75% of the layer mass; The reinforcing phase, selected from carbon fiber bundles, comprises 25-35% of the layer mass. An interface modifier, wherein the interface modifier is selected from nano-titanium nitride particles, accounting for 0.5-1.5% of the mass of the layer.

4. The method for producing a motor housing according to claim 1, characterized in that, The preparation process of the composite material layer is as follows: Carbon fiber bundles are impregnated in an ethanol dispersion containing nano-titanium nitride and treated with ultrasonic vibration for 30-60 minutes to form a uniform modified coating on the carbon fiber surface, thereby forming modified carbon fibers. Modified carbon fiber and aluminum alloy powder are mixed in a certain mass ratio and a mixer is used to perform spatial gradient mixing at a preset speed to form a preform with axially distributed fibers. The preform is placed into a vacuum hot press mold and held at 480-520℃ and 50-80MPa for 20-40 minutes to completely densify the aluminum alloy powder and combine it with carbon fiber to obtain a thin composite plate. The composite sheet is laser-precision cut into irregular shapes that match the spin-formed shell, in order to obtain the corresponding composite material layer.

5. The method for producing a motor housing according to claim 1, characterized in that, The process of bonding the composite material layer to the shell substrate using laser welding in a predetermined area of ​​the spun shell, and achieving metallurgical bonding of dissimilar material interfaces through energy control to form a composite shell substrate with a gradient structure, specifically includes the following steps: Laser texturing is performed on the surface of a preset area of ​​the spun shell, and the texturing area is formed by processing a micro-dimple array using a pulsed laser. The composite material layer is pre-installed into the texturing treatment area, and a clamping force of 0.8-1.5MPa is applied by an auxiliary positioning system, while the interface gap is monitored in real time by infrared thermal imaging. A coaxial dual-beam laser welding system is used to simultaneously output continuous wave and pulse wave, controlling the melting depth ratio between the shell matrix and the composite material layer to be 1:0.6~0.8, forming a gradient transition metallurgical bonding interface; During the welding process, Al-Si-Ti composite powder is sprayed simultaneously, and Al3Ti reinforcing phase is generated through in-situ reaction in the molten pool. This causes the hardness of the metallurgical bonding interface to transition from the first hardness gradient of the shell matrix to the second hardness of the composite layer, forming a composite shell matrix with a gradient structure.

6. The method for producing a motor housing according to claim 1, characterized in that, A biomimetic heat dissipation structure is formed on the inner surface of the composite shell substrate using an electrochemical processing technique, and a functional surface layer is simultaneously deposited in key areas to form an inner shell cavity with directional heat dissipation characteristics. Specifically, this includes the following steps: An elastic silicone mask is attached to the inner surface of the composite shell substrate, and a biomimetic scale pattern is transferred by mechanical imprinting to form a physical shielding layer with anti-electrolytic corrosion properties. The casing is immersed in a high-speed circulating electrolyte, and ultrasonic-assisted electrolytic processing is used to control the current density and form a gradient transition heat dissipation fin substrate. During the electrolytic processing, pulsed composite plating is performed simultaneously, with forward and reverse currents applied alternately to co-deposit Al2O3 nanoparticles and graphene sheets on the surface of the heat dissipation fins, forming a directional heat-conducting layer. A micro-nano composite structure is constructed on the surface of the directional thermally conductive layer by plasma activation treatment. The micro-nano composite structure includes several regularly distributed surface pores. The heat dissipation fins are smoothed using an abrasive flow polishing system to control surface roughness and form an inner cavity in the housing with directional heat dissipation characteristics.

7. The method for producing a motor housing according to claim 1, characterized in that, An integrated cooling channel is fabricated on the outer surface of the composite housing substrate using a combination of additive and subtractive manufacturing processes. The channel is then filled with a composite phase change material to construct a three-dimensional heat dissipation network, resulting in the motor housing. Specifically, the housing includes: Titanium alloy powder was deposited on the outer surface of the composite shell substrate by selective laser melting to construct a substrate channel with a preset width and a depth-to-width ratio of 1:

4. Ultra-high pressure water jet is used to perform subtractive processing on the sidewalls of the substrate channel to remove slag and control surface roughness, forming a precision flow channel with a preset cross-sectional tolerance; A second-thickness porous ceramic layer is generated by plasma electrolytic oxidation treatment on the inner wall of the precision flow channel, wherein the micropore size distribution of the porous ceramic layer is 50~150nm; The composite phase change material is heated to a molten state, and the porous ceramic layer is filled by a vacuum impregnation process. After cooling and solidification, the phase change enthalpy value is made greater than the preset enthalpy value. Laser micro-cladding technology is used to clad a Ni-based alloy sealing layer at the opening of the precision flow channel to form an airtight closed channel, thereby constructing a three-dimensional heat dissipation network. The equivalent thermal conductivity of a three-dimensional heat dissipation network is detected online using the transient planar heat source method, and the heat dissipation levels of the motor housing are classified and sorted.

8. A motor housing, manufactured using the method for producing a motor housing as described in any one of claims 1 to 7, characterized in that, The motor housing specifically includes: The shell base is a spin-formed shell with a predetermined curved shape, formed by a spinning process; Gradient composite layer, formed by bonding composite material layer to shell matrix through laser welding; The housing cavity has directional heat dissipation features; Integrated cooling channels are closed flow channels processed on the outer surface of the composite shell substrate using a combination of additive and subtractive manufacturing processes.

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