Marine explosion-proof variable frequency motor

Abstract

The invention relates to the technical field of variable frequency motors, and discloses a marine anti-explosion variable frequency motor which comprises a motor shell, a heat conduction ring is fixedly connected to the front end of the outer wall of the motor shell, a heat conduction shell is fixedly connected to the outer wall of the heat conduction ring, and a limiting column is rotationally connected to the outer wall of the heat conduction ring. The outer wall of the limiting column is fixedly connected with a gear, the tooth end of the gear is in meshed connection with a gear ring, the outer wall of the limiting column is fixedly connected with a heat conduction rod, the outer wall of the heat conduction rod is attached to the inner wall of the heat conduction shell, heat dissipation fins are arranged on the outer wall of the heat conduction rod, and the outer wall of the gear ring is fixedly connected with a fixing column. The stirring column is pulled to drive the fixing column to rotate, through cooperation of the gear ring, the heat conduction shell, the gear and the limiting column, the heat conduction rod and the heat dissipation fins are screwed out of the interior of the heat conduction shell, the heat dissipation fins take away heat through convection, the heat dissipation fins are unfolded at the high temperature to increase the working heat dissipation area of the motor shaft body, and the fluid resistance is reduced when the motor shaft body is closed in the sailing process.

Description

Technical Field

[0001] The invention relates to the technical field of variable frequency motors, in particular to a marine explosion-proof variable frequency motor. Background Art

[0002] In the field of ships, with the rapid development of the shipping industry and the continuous emergence of various new types of ship equipment, extremely stringent requirements are placed on the performance and safety of marine motors. The operating environment of ships is complex, and often involves the transportation or storage of flammable and explosive goods, such as crude oil and natural gas. At the same time, the internal space of the ship is relatively closed and the ventilation conditions are limited. Once the motor generates electric sparks or overheats, it is very easy to cause serious safety accidents such as explosions. Traditional marine motors have certain limitations in explosion-proof performance and are difficult to meet the growing safety needs of current ship operations. Against this background, marine explosion-proof variable frequency motors came into being. They combine advanced explosion-proof technology with variable frequency speed regulation technology. They can effectively avoid the generation of dangerous factors that may cause explosions during operation, and can accurately adjust the motor speed according to different working conditions of the ship to achieve energy saving and efficiency improvement, becoming a key equipment to ensure the safe and efficient operation of ships.

[0003] The heat dissipation method of traditional marine explosion-proof variable frequency motors is to dissipate heat by adding cooling fins. When the motor is in the shutdown state, the cooling fins cannot be retracted, which will increase fluid resistance during navigation. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a marine explosion-proof variable frequency motor to solve the problem that the cooling fins cannot be folded up when the motor is in a shutdown state, which increases the fluid resistance during navigation.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: a marine explosion-proof variable frequency motor, comprising a motor housing, a heat-conducting ring is fixedly connected to the front end of the outer wall of the motor housing, the outer wall of the heat-conducting ring is fixedly connected to the heat-conducting shell, the outer wall of the heat-conducting ring is rotatably connected to a limiting column, the outer wall of the limiting column is fixedly connected to a gear, the tooth end of the gear is meshingly connected with a gear ring, the outer wall of the limiting column is fixedly connected to a heat-conducting rod, the outer wall of the heat-conducting rod is attached to the inner wall of the heat-conducting shell, the outer wall of the heat-conducting rod is provided with cooling fins, the outer wall of the gear ring is fixedly connected to a fixing column, the outer wall of the fixing column is fixedly connected to a positioning column, both sides of the outer wall of the fixing column are fixedly connected to baffle rods, the outer wall of the baffle rod is slidably connected to a toggle column, the outer wall of the toggle column is fixedly connected to a tension spring, and the outer wall of the heat-conducting shell is provided with a limiting groove.

[0006] Preferably, the outer wall of the gear ring is rotatably connected to the inner wall of the heat-conducting shell, the outer wall of the tension spring is fixedly connected to the outer wall of the heat-conducting ring, and the outer wall of the toggle column is attached to the inner wall of the limiting groove.

[0007] Preferably, a driving assembly is provided inside the motor housing. The driving assembly includes a motor body and a motor shaft. The motor body is disposed inside the driving assembly, and the outer wall of the motor shaft is rotatably connected to the inner wall of the motor housing.

[0008] Preferably, the method for manufacturing the motor housing includes the following steps: S1. Material preparation: Select alloy steel plates as the raw materials for the motor housing. S2. Housing forming: Cut through a cutting device, and then adopt a pressure forming process to initially form each module of the main shape of the motor housing. S3. Housing welding: Weld the initially formed modules of the motor housing by using an inert gas shielded welding process to form the modules into the motor housing. S4. Machining: Machine the welded motor housing. S5. Surface treatment: Perform surface treatment on the machined motor housing. S6. Inspection step: Perform explosion-proof performance inspection and mechanical performance inspection on the motor housing after step S5.

[0009] Preferably, the chemical composition of the alloy steel plates in S1, by mass percentage, includes: carbon 0.15% - 0.25%, silicon 0.2% - 0.5%, manganese 0.6% - 1.0%, chromium 1.0% - 1.5%, nickel 0.5% - 1.0%, and the rest is iron and inevitable impurities. Preferably, S2 includes the following steps: S201. First, apply a lubricant on the surface of the plate. The lubricant is a graphite-based lubricant to completely cover the surface of the plate. S202. Cut the alloy steel plate coated with the graphite-based lubricant through a cutting device into plates of each part that meet the design dimensions of the motor housing. S203. Hydraulically form the cut alloy plates by using a press. Perform stamping and bending operations on the cut plates on the press to initially form the main shape of the motor housing.

[0010] Preferably, the inert gas in S3 is helium. Weld each module of the initially formed motor housing main body. First, perform preheating treatment on the parts to be welded of the two modules. The preheating temperature is 100 - 120°C. During the welding process, control the welding current at 120 - 150A, the welding voltage at 20 - 22V, and the welding speed at 15 - 20 cm / min.

[0011] Preferably, in S4, the drawing data is imported into a control terminal of a numerically controlled machine tool, and drilling and boring operations are performed on the welded motor housing by the numerically controlled machine tool.

[0012] Preferably, S5 comprises the following steps: S501, soaking the processed motor housing in a solution containing 5% to 10% sodium hydroxide to cause a saponification reaction, decomposing the grease on the motor housing into water-soluble substances, and the soaking time is 10 to 30 minutes; S502, immersing the degreased motor housing into molten zinc liquid, wherein the thickness of the hot-dip galvanizing coating is between 30 and 100 μm; S503, immersing the galvanized shell in a passivation solution, wherein the components of cerium nitrate in the passivation solution include, by mass ratio, 0.5% to 3% cerium nitrate, 0.5% to 2% hydrogen peroxide, 0.5% to 2% citric acid, and the rest is deionized water.

[0013] Preferably, the explosion-proof performance test in S6 adopts a simulated explosion test, in which a mixture of methane and air is ignited inside the motor housing, with the volume ratio of methane being 5% to 15%, and whether there is a flame coming out of the outside of the housing. The mechanical property inspection is carried out using a Rockwell hardness tester, and the test part is the welding part of the motor housing, to detect whether the Rockwell hardness reaches 90HRB or above.

[0014] The present invention provides a marine explosion-proof variable frequency motor, which has the following beneficial effects: 1. In the present invention, the fixed column is driven to rotate by pulling the toggle column, and the heat-conducting rod and the heat-dissipating fins are rotated out from the inside of the heat-conducting shell through the cooperation of the gear ring, the heat-conducting shell, the gear, and the limit column. The heat-dissipating fins take away the heat through convection, and are expanded at high temperatures to increase the working heat dissipation area of ​​the motor shaft, and are closed during navigation to reduce the effect of fluid resistance.

[0015] 2. In the present invention, the motor housing is immersed in a solution containing 5% to 10% sodium hydroxide for 10 to 30 minutes to remove grease on the surface, a 30 to 100 μm galvanized layer is formed by hot-dip galvanizing, and the galvanized housing is immersed in a passivation solution to form a dense passivation film on the surface of the galvanized layer, thereby preventing external oxygen, moisture and corrosive media from contacting the galvanized layer, further enhancing the corrosion resistance of the motor housing and extending the service life.

[0016] 3. In the present invention, a graphite-based lubricant is first applied to the surface of the alloy steel plate to reduce friction, and then the plate is precisely cut with a cutting device. Due to the effect of the lubricant, the cutting surface is smooth. The plate is punched and bent, and its internal grains are refined, and its toughness and fatigue resistance are improved, so that the molded motor housing is strong and can withstand the effects of various forces during motor operation.

[0017] 4. In the present invention, alloy plates are selected, cut, stamped and bent by a press, and then the modules are welded into a motor housing under the protection of an inert gas. The surface of the motor housing is passivated and then inspected to achieve the effect of improving the overall performance of the motor housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A perspective view of the present invention; Figure 2 It is an exploded schematic diagram of the drive assembly structure of the present invention; Figure 3 It is a schematic diagram of the partial structure of the gear of the present invention; Figure 4 It is a schematic diagram of the partial structure of the gear ring of the present invention; Figure 5 It is a schematic diagram of the local structure of the toggle column of the present invention; Figure 6 for Figure 5 A magnified schematic diagram of point A; Figure 7 It is a schematic diagram of the process of the present invention.

[0019] Among them, 1. Motor housing; 2. Drive assembly; 201. Motor body; 202. Motor shaft; 3. Heat-conducting ring; 4. Heat-conducting housing; 5. Limiting column; 6. Gear; 7. Gear ring; 8. Heat-conducting rod; 9. Cooling fins; 10. Fixed column; 11. Positioning column; 12. Stop lever; 13. Toggle column; 14. Tension spring; 15. Limiting groove. DETAILED DESCRIPTION

[0020] The technical solution of the present invention will be described clearly and completely below in conjunction with the drawings of the specification. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Please see attached Figure 1 ~Attached Figure 6The embodiment of the present invention provides a marine explosion-proof variable frequency motor, including a motor housing 1, a heat-conducting ring 3 is fixedly connected to the front end of the outer wall of the motor housing 1, a heat-conducting shell 4 is fixedly connected to the outer wall of the heat-conducting ring 3, a limiting column 5 is rotatably connected to the outer wall of the heat-conducting ring 3, a gear 6 is fixedly connected to the outer wall of the limiting column 5, a gear 6 is meshingly connected to the tooth end of the gear 6 with a gear ring 7, a heat-conducting rod 8 is fixedly connected to the outer wall of the limiting column 5, the outer wall of the heat-conducting rod 8 is attached to the inner wall of the heat-conducting shell 4, and the outer wall of the heat-conducting rod 8 is provided with cooling fins 9, a fixing column 10 is fixedly connected to the outer wall of the gear ring 7, a positioning column 11 is fixedly connected to the outer wall of the fixing column 10, both sides of the outer wall of the fixing column 10 are fixedly connected to the blocking rod 12, the outer wall of the blocking rod 12 is slidably connected to the toggle column 13, the outer wall of the toggle column 13 is fixedly connected to the tension spring 14, and a limiting groove 15 is provided on the outer wall of the heat-conducting shell 4.

[0022] Specifically, by pulling the toggle post 13 outward and then pulling the toggle post 13 toward the other side of the limit slot 15, the tension spring 14 is stretched when the toggle post 13 is pulled outward, wherein due to the action of the blocking rod 12, the toggle post 13 will not rotate around the fixed post 10, so that the fixed post 10 is driven to rotate when the toggle post 13 rotates, and the positioning post 11 prevents the toggle post 13 from falling off. When the toggle post 13 is pulled to the other side of the limit slot 15, the gear ring 7 is synchronously driven to rotate inside the heat-conducting housing 4. Since the heat-conducting housing 4 and the gear 6 are meshed, the gear 6 is driven to rotate. The rotation of the gear 6 drives the limit post 5 to rotate, and then the heat-conducting rod 8 and the heat-dissipating fins 9 are driven to rotate around the limit post 5, so that the heat-conducting rod 8 and the heat-dissipating fins 9 are rotated around the limit post 5, so that the heat-conducting rod 8 and the heat-dissipating fins 9 are rotated outward, and the heat-conducting rod 8 is exposed to the flowing air. The heat conduction of the heat-conducting ring 3 is used to dissipate the heat generated when the motor body 201 drives the motor shaft 202 to rotate The heat generated by the friction between the motor shaft 202 and the motor housing 1 is conducted to the inside of the heat-conducting housing 4, and the heat conducted by the heat-conducting ring 3 is partially transmitted to the inside of the heat-conducting rod 8 and the heat dissipation fins 9 through the gear 6. Since the heat-conducting rod 8 fits with the heat-conducting housing 4 and the heat-conducting housing 4 contacts with the heat-conducting ring 3, the heat of the heat-conducting ring 3 and the limiting column 5 is conducted to the inside of the heat dissipation fins 9, and contacts with air molecules through the heat dissipation fins 9, thereby taking away the heat by convection. When the heat-conducting rod 8 is completely screwed out of the heat-conducting housing 4, the toggle column 13 is pulled inward so that the toggle column 13 is stuck on the inner wall of the limiting groove 15. Due to the tension of the tension spring 14 and the gravity of the heat dissipation fins 9 themselves, the gear ring 7 is pushed to rotate in the opposite direction, so that the toggle column 13 is tightly fitted to the inner wall of the limiting groove 15 without loosening, thereby achieving the effect of expanding at high temperature to increase the working heat dissipation area of ​​the motor shaft 202 and closing during navigation to reduce fluid resistance.

[0023] Please see attached Figure 1 ~Attached Figure 6, the outer wall of the gear ring 7 is rotatably connected to the inner wall of the heat-conducting housing 4, the outer wall of the tension spring 14 is fixedly connected to the outer wall of the heat-conducting ring 3, and the outer wall of the shifting column 13 is fitted to the inner wall of the limiting groove 15.

[0024] Specifically, through the limitation of the heat-conducting housing 4, the gear ring 7 is prevented from falling off, ensuring the normal operation of the whole. By arranging the outer wall of the tension spring 14 on the outer wall of the heat-conducting ring 3, it ensures the function that the heat-conducting ring 3 can normally pull the shifting column 13 to move. By fitting the shifting column 13 with the limiting groove 15, the shifting column 13 is prevented from rotating in the reverse direction, ensuring the stability of the whole device.

[0025] Please refer to the appendix Figure 2 , a driving component 2 is arranged inside the motor housing 1. The driving component 2 includes a motor body 201 and a motor shaft body 202. The motor body 201 is arranged inside the driving component 2, and the outer wall of the motor shaft body 202 is rotatably connected to the inner wall of the motor housing 1.

[0026] Specifically, the driving component 2 is divided into two modules, and the motor shaft body 202 is separately separated into an independent component, achieving the effect of modular maintenance and reducing the downtime. Among them, the motor housing 1 is used to fix the position of the motor body 201 and also provides basic support for the motor shaft body 202.

[0027] Please refer to the appendix Figure 7 , the manufacturing method of the motor housing 1 includes the following steps: S1. Material preparation: Select alloy steel plate as the raw material of the motor housing 1; S2. Housing forming: Cut through a cutting device, and then adopt a pressure forming process to initially form each module of the main shape of the motor housing 1; S3. Housing welding; Adopt an inert gas shielded welding process to weld the initially formed modules of the motor housing 1, so that the modules are formed into the motor housing 1; S4. Machining: Machine the welded motor housing 1; S5. Surface treatment: Perform surface treatment on the machined motor housing 1; S6. Inspection step: Inspect the explosion-proof performance and mechanical performance of the motor housing 1 after step S5.

[0028] Specifically, in step S1, the alloy steel plate has high strength and toughness. The high strength can withstand various stresses generated during operation and possible external impacts, ensuring that the housing will not easily deform or break during long-term use. The good toughness enables it to absorb energy without brittle fracture when subjected to impact or vibration, improving the reliability and safety of the housing; In step S2, the cutting device can perform precise cutting according to preset dimensions and shapes, ensuring high dimensional accuracy for each module. The pressure forming process shapes the cut material to be closer to the final design shape. In step S3, the inert gas can form a protective gas shield around the arc during the welding process, effectively isolating the air, preventing harmful gases such as oxygen and nitrogen from contacting the high-temperature metal, avoiding metal oxidation and nitridation, reducing welding defects such as pores and slag inclusions, and improving the quality and performance of the welded joint. In step S4, the motor housing 1 is processed to achieve the dimensional accuracy required by the design, ensuring the fitting accuracy between the motor housing 1 and the internal components, and guaranteeing the normal assembly and operation of the motor. In step S5, through surface treatment, a dense protective film can be formed on the surface of the motor housing 1, isolating the metal matrix from the external corrosive medium, effectively preventing corrosion from occurring, and extending the service life of the motor housing 1. In step S6, through the explosion-proof performance inspection, it can be ensured that the motor housing 1 can prevent the internal explosion flame from spreading to the external environment under conditions such as the designed pressure and temperature, avoiding the occurrence of explosion accidents, and ensuring the safety of the ship and personnel. The mechanical performance inspection can evaluate the mechanical performance indicators of the strength, stiffness, and toughness of the motor housing to ensure that the motor housing 1 can withstand these external forces without deformation, rupture, or damage.

[0029] In S1, the chemical composition of the alloy steel plate by mass percentage includes: carbon 0.15% - 0.25%, silicon 0.2% - 0.5%, manganese 0.6% - 1.0%, chromium 1.0% - 1.5%, nickel 0.5% - 1.0%, and the rest is iron and inevitable impurities.

[0030] Specifically, carbon can dissolve into the lattice of iron to form an interstitial solid solution, causing lattice distortion, thereby increasing the strength and hardness of the steel. Manganese forms manganese sulfide with sulfur, reducing the harmful effects of sulfur, improving the hot working performance of the steel, and also increasing the hardenability of the steel, enabling the steel to obtain better mechanical properties after heat treatment. Chromium can form a dense oxide film on the surface of the steel, improving the corrosion resistance of the steel. Nickel can dissolve into the lattice of iron, increasing the lattice stability and reducing the dissolution rate of the steel in the corrosive medium. Silicon can increase the strength and hardness of the steel without reducing its toughness and plasticity, which is beneficial to the processing and forming of the steel.

[0031] S2 includes the following steps: S201. First, apply a lubricant on the surface of the plate. The lubricant is a graphite-based lubricant, and the graphite-based lubricant completely covers the surface of the plate. S202. Cut the alloy steel plates coated with graphite-based lubricant into plates of various parts that meet the design dimensions of the motor housing 1 through a cutting device; S203. Hydraulically form the cut alloy plates using a press. Perform stamping and bending operations on the cut plates on the press to initially form the main shape of the motor housing 1.

[0032] Specifically, in step S201, graphite has good lubricating properties and can form a lubricating film on the surface of the plates, reducing the friction coefficient between the plates and the molds or processing equipment. In the subsequent processing, it makes the plates easier to deform in the molds, improves the processing accuracy, and reduces surface scratches and wear caused by friction; In step S202, due to the action of the lubricant, the cutting process is more stable, which can effectively reduce burrs, cracks and roughness on the cutting surface, make the cutting surface smoother and flatter, and improve the overall performance of the motor housing 1; In step S203, through stamping and bending processes, the cut modules are plastically deformed under pressure, and the internal grain structure is refined and optimized, improving the toughness and fatigue resistance of the material, making the motor housing more robust and durable, and capable of withstanding various forces and vibrations during the operation of the motor.

[0033] In S3, the inert gas is helium. Weld the various modules of the preliminarily formed main body of the motor housing 1. First, preheat the parts to be welded of the two modules. The preheating temperature is 100 - 120 °C. During the welding process, control the welding current to be 120 - 150 A, the welding voltage to be 20 - 22 V, and the welding speed to be 15 - 20 cm / min.

[0034] Specifically, helium can make the arc burn more stably, reduce the drift and fluctuation of the arc, and make the weld formation good. Preheating can make the metal at the welding part reach a certain temperature before welding, reduce the temperature difference of the welded parts during the welding process, thereby reducing the welding stress and improving the structural stability of the motor housing. The welding current of 120 - 150 A, voltage of 20 - 22 V and welding speed of 15 - 20 cm / min match each other, which can ensure that the energy of the arc is moderate, and make the base metal and the filler metal fully melt and fuse well during the welding process.

[0035] In S4, import the drawing data into the control terminal of the numerical control machine tool, and perform drilling and boring operations on the welded and formed motor housing 1 through the numerical control machine tool.

[0036] Specifically, the numerical control machine tool can operate according to accurate drawing data, ensure that the position and dimension accuracy of drilling and boring are within a very small error range, ensure the accurate installation and fit of the internal components of the motor housing 1, and improve the overall stability.

[0037] S5 includes the following steps; S501. Immerse the processed motor housing 1 in a solution containing 5% - 10% sodium hydroxide for saponification reaction to decompose the grease on the motor housing 1 into water-soluble substances, and the immersion time is 10 - 30 minutes; S502. Immerse the degreased motor housing 1 into the molten zinc solution, and the thickness of the hot-dip galvanized coating is between 30 - 100 μm; S503. Immerse the galvanized housing in the passivation solution. The components of cerium nitrate in the passivation solution, by mass ratio, include: cerium nitrate 0.5% - 3%, hydrogen peroxide 0.5% - 2%, citric acid 0.5% - 2%, and the rest is deionized water.

[0038] Specifically, in step S501, the grease on the surface of the motor housing 1 during the machining process of the CNC machine tool in S4 can be decomposed into water-soluble substances, thereby removing the contaminated lubricating oil and cutting oil, and ensuring the cleanliness of the housing surface; In step S502, place the already cleaned motor housing 1 in the molten zinc solution, so that a layer of hot-dip galvanized coating is formed on the surface of the motor housing 1. The thickness of the hot-dip galvanized coating is between 30 - 100 μm, and it is firmly bonded to the matrix of the motor housing 1, which can provide long-term protection, reducing the cost and workload of later maintenance and repair; In step S503, cerium nitrate, hydrogen peroxide and citric acid interact with each other to form a dense passivation film on the surface of the galvanized coating, preventing the external oxygen, moisture and corrosive media from contacting the galvanized coating, enhancing the corrosion resistance of the motor housing 1 and prolonging its service life.

[0039] In S6, the explosion-proof performance test adopts a simulated explosion test. Ignite the mixture of methane and air inside the motor housing 1, and the volume ratio of methane is 5% - 15%. Observe whether there is flame transmission outside the housing. The mechanical property inspection is carried out using a Rockwell hardness tester, and the test location is the welding part of the motor housing 1 to detect whether the Rockwell hardness reaches above 90 HRB.

[0040] Specifically, through the simulated explosion test, it is checked whether the motor housing 1 can effectively prevent the flame and high-temperature gas generated by the internal explosion from spreading out, thereby avoiding triggering an explosion in the external environment and ensuring the safety of personnel and equipment. Use a Rockwell hardness tester to test the hardness of the welding part to check whether the hardness can reach above 90 HRB, so as to avoid the effect of damaging the motor housing 1 by various forces generated during operation.

[0041] The following is introduced in combination with specific embodiments: Example 1 The preparation method of the motor housing 1 includes the following steps: S1. Material preparation: Select alloy steel plates. The chemical composition is by mass percentage: carbon 0.25%, silicon 0.5%, manganese 1.0%, chromium 1.5%, nickel 1.0%, and the rest is iron and inevitable impurities.

[0042] S2. Shell forming: Apply graphite-based lubricant on the surface of the plate to completely cover the surface of the plate. Cut the alloy steel plate coated with lubricant into individual plate parts that meet the design dimensions of the motor shell through a cutting device. Perform stamping and bending operations on the cut plates on a press to initially form the main shape of the motor shell 1.

[0043] S3. Shell welding: Preheat the welding parts before welding. The preheating temperature is 120°C. Use helium as the shielding gas. The welding current during welding is 150 A, the welding voltage is 22 V, and the welding speed is 20 cm / min.

[0044] S4. Machining: Import the drawing data into the control terminal of the numerical control machine tool, and perform drilling and boring operations on the welded motor shell 1 through the numerical control machine tool.

[0045] S5. Surface treatment: Immerse the processed motor shell 1 in a solution containing 10% sodium hydroxide for 30 minutes to carry out saponification reaction to remove the grease during the processing. Immerse the degreased motor shell 1 in molten zinc solution. The thickness of the hot-dip galvanized coating is 100 μm. Immerse the galvanized motor shell 1 in the passivation solution. The composition of the passivation solution is by mass ratio: cerium nitrate 3%, hydrogen peroxide 2%, citric acid 2%, and the rest is deionized water.

[0046] S6. Inspection steps: Ignite the methane-air mixture inside the motor shell 1 that has been passivated and formed. The volume ratio of methane is 15%. Observe whether there is any flame coming out of the outside of the motor shell 1. Use a Rockwell hardness tester to test the hardness of the welding part of the motor shell 1 to check whether it reaches above 90 HRB.

[0047] Example 2 S1. Material preparation: Select alloy steel plates. The chemical composition is by mass percentage: carbon 0.2%, silicon 0.35%, manganese 0.8%, chromium 1.25%, nickel 0.75%, and the rest is iron and inevitable impurities.

[0048] S2. Shell forming: Apply graphite-based lubricant on the surface of the plate to completely cover the surface of the plate. Cut the alloy steel plate coated with lubricant into individual plate parts that meet the design dimensions of the motor shell through a cutting device. Perform stamping and bending operations on the cut plates on a press to initially form the main shape of the motor shell 1.

[0049] S3. Shell Welding: Preheat the welding area to 110°C before welding. Use helium as the shielding gas. The welding current during welding is 135 A, the welding voltage is 21 V, and the welding speed is 17 cm / min.

[0050] S4. Machining: Import the drawing data into the control terminal of the numerical control machine tool, and perform drilling and boring operations on the welded motor shell 1 through the numerical control machine tool.

[0051] S5. Surface Treatment: Immerse the processed motor shell 1 in a solution containing 7% sodium hydroxide for 20 minutes to carry out saponification reaction to remove the grease during the processing. Immerse the degreased motor shell 1 in molten zinc solution, and the thickness of the hot-dip galvanized coating is 65 μm. Immerse the galvanized motor shell 1 in the passivation solution. The composition of the passivation solution is by mass ratio, cerium nitrate 1.75%, hydrogen peroxide 1.25%, citric acid 1.25%, and the rest is deionized water.

[0052] S6. Inspection Procedure: Ignite the methane-air mixture inside the motor shell 1 that has been passivated and formed. The volume ratio of methane is 10%. Observe whether there is any flame coming out from the outside of the motor shell 1. Use a Rockwell hardness tester to test the hardness of the welding area of the motor shell 1 and check whether it reaches above 90 HRB. Example 3 S1. Material Preparation: Select alloy steel plates. The chemical composition is by mass percentage, carbon 0.15%, silicon 0.2%, manganese 0.6%, chromium 1.0%, nickel 0.5%, and the rest is iron and unavoidable impurities.

[0053] S2. Shell Forming: Apply graphite-based lubricant on the surface of the plate to completely cover the surface of the plate. Cut the alloy steel plate coated with lubricant into various parts of the plate that meet the design dimensions of the motor shell through cutting equipment. Perform stamping and bending operations on the cut plate on the press to initially form the main shape of the motor shell 1.

[0054] S3. Shell Welding: Preheat the welding area to 100°C before welding. Use helium as the shielding gas. The welding current during welding is 120 A, the welding voltage is 20 V, and the welding speed is 15 cm / min.

[0055] S4. Machining: Import the drawing data into the control terminal of the numerical control machine tool, and perform drilling and boring operations on the welded motor shell 1 through the numerical control machine tool.

[0056] S5. Surface treatment: Immerse the processed motor housing 1 in a solution containing 5% sodium hydroxide for 10 minutes to carry out saponification reaction to remove the grease during the processing. Immerse the degreased motor housing 1 in molten zinc liquid, and the thickness of the hot-dip galvanized coating is 30 μm. Immerse the galvanized motor housing 1 in a passivation solution. The composition of the passivation solution is by mass ratio: cerium nitrate 0.5%, hydrogen peroxide 0.5%, citric acid 0.5%, and the rest is deionized water.

[0057] S6. Inspection steps: Ignite the methane-air mixture inside the motor housing 1 that has been passivated and formed. The volume ratio of methane is 5%. Observe whether there is a flame coming out of the outside of the motor housing 1. Use a Rockwell hardness tester to test the hardness of the welding part of the motor housing 1 and check whether it reaches above 90 HRB.

[0058] Experimental table: Attribute Example 1 Example 2 Example 3 Prior Art Tensile Strength 500 - 55 (MPa) 480 - 52 (MPa) 450 - 50 (MPa) 400 - 45 (MPa) Salt Spray Test Time ≥1000(h) ≥800(h) ≥500(h) 500～700(h) Service Life ≥15 (years) ≥12 (years) ≥10 (years) 8 - 10 (years) Elongation 12～15％ 14～16％ 16～18％ 10～12％ Through the comparison of the above data, the method for preparing the motor housing 1 can comprehensively improve the performance of the motor housing 1.

[0059] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A marine explosion-proof variable frequency motor, comprising a motor housing (1), characterized in that: The front end of the outer wall of the motor housing (1) is fixedly connected to a heat-conducting ring (3), the outer wall of the heat-conducting ring (3) is fixedly connected to a heat-conducting housing (4), the outer wall of the heat-conducting ring (3) is rotatably connected to a limiting column (5), the outer wall of the limiting column (5) is fixedly connected to a gear (6), the tooth end of the gear (6) is meshingly connected to a gear ring (7), the outer wall of the limiting column (5) is fixedly connected to a heat-conducting rod (8), the outer wall of the heat-conducting rod (8) is attached to the inner wall of the heat-conducting housing (4), The outer wall of the heat-conducting rod (8) is provided with a heat dissipation fin (9), the outer wall of the gear ring (7) is fixedly connected to a fixing column (10), the outer wall of the fixing column (10) is fixedly connected to a positioning column (11), both sides of the outer wall of the fixing column (10) are fixedly connected to a blocking rod (12), the outer wall of the blocking rod (12) is slidably connected to a toggle column (13), the outer wall of the toggle column (13) is fixedly connected to a tension spring (14), and the outer wall of the heat-conducting housing (4) is provided with a limiting groove (15).

2. A marine explosion-proof variable frequency motor according to claim 1, characterized in that: The outer wall of the gear ring (7) is rotatably connected to the inner wall of the heat-conducting housing (4), the outer wall of the tension spring (14) is fixedly connected to the outer wall of the heat-conducting ring (3), and the outer wall of the toggle column (13) is fitted to the inner wall of the limiting groove (15).

3. A marine explosion-proof variable frequency motor according to claim 1, characterized in that: A drive assembly (2) is arranged inside the motor housing (1), and the drive assembly (2) comprises a motor body (201) and a motor shaft (202); the motor body (201) is arranged inside the drive assembly (2), and the outer wall of the motor shaft (202) is rotatably connected to the inner wall of the motor housing (1).

4. The marine explosion-proof variable frequency motor according to claim 1, characterized in that: The method for preparing the motor housing (1) comprises the following steps: S1. Material preparation: selecting alloy steel plate as the raw material of the motor housing (1); S2, shell molding: cutting by cutting equipment, and then using a pressure molding process to preliminarily form various modules of the main shape of the motor shell (1); S3, casing welding; welding the modules of the initially formed motor casing (1) by using an inert gas shielded welding process, so that the modules are formed into the motor casing (1); S4, machining: machining the motor housing (1) after welding; S5, surface treatment: performing surface treatment on the motor housing (1) after machining; S6. Inspection step: After step S5, the motor housing (1) is inspected for explosion-proof performance and mechanical properties.

5. A marine explosion-proof variable frequency motor according to claim 4, characterized in that: The chemical composition of the alloy steel plate in S1, calculated by mass percentage, includes: 0.15% to 0.25% carbon, 0.2% to 0.5% silicon, 0.6% to 1.0% manganese, 1.0% to 1.5% chromium, 0.5% to 1.0% nickel, and the rest is iron and unavoidable impurities.

6. A marine explosion-proof variable frequency motor according to claim 4, characterized in that: The S2 comprises the following steps: S201, firstly applying a lubricant on the surface of the plate, wherein the lubricant is a graphite-based lubricant, so that the graphite-based lubricant completely covers the surface of the plate; S202, cutting the alloy steel plate coated with the graphite-based lubricant into plates of various parts conforming to the design dimensions of the motor housing (1) by means of a cutting device; S203, the cut alloy plates are hydraulically formed using a press, and the cut plates are punched and bent on the press, so that each plate is initially formed into the main shape of the motor housing (1).

7. The marine explosion-proof variable frequency motor according to claim 4, characterized in that: The inert gas in S3 is helium. The modules of the preliminarily formed motor housing (1) body are welded. First, the parts of the two modules to be welded are preheated at a temperature of 100 to 120° C. During the welding process, the welding current is controlled to be 120 to 150 A, the welding voltage is 20 to 22 V, and the welding speed is 15 to 20 cm / min.

8. The marine explosion-proof variable frequency motor according to claim 4, characterized in that: In S4, the drawing data is imported into the control end of the CNC machine tool, and the CNC machine tool performs drilling and boring operations on the welded motor housing (1).

9. The marine explosion-proof variable frequency motor according to claim 4, characterized in that: The S5 comprises the following steps: S501, soaking the processed motor housing (1) in a solution containing 5% to 10% sodium hydroxide to cause a saponification reaction, thereby decomposing the grease on the motor housing (1) into a water-soluble substance, and the soaking time is 10 to 30 minutes; S502, immersing the degreased motor housing (1) into molten zinc liquid, wherein the thickness of the hot-dip galvanizing coating is between 30 μm and 100 μm; S503, immersing the galvanized shell in a passivation solution, wherein the components of cerium nitrate in the passivation solution include, by mass ratio, 0.5% to 3% cerium nitrate, 0.5% to 2% hydrogen peroxide, 0.5% to 2% citric acid, and the rest is deionized water.

10. The marine explosion-proof variable frequency motor according to claim 4, characterized in that: The flameproof performance test in S6 adopts a simulated explosion test, in which a mixture of methane and air is ignited inside the motor housing (1), with the volume ratio of methane being 5% to 15%, and whether there is flame coming out of the outside of the housing. The mechanical performance test is carried out using a Rockwell hardness tester, and the test part is the welding part of the motor housing (1), to detect whether the Rockwell hardness reaches 90HRB or above.

Images