Submersible pump frequency conversion control device

Abstract

The utility model provides a submersible pump frequency conversion control device, and belongs to the technical field of water pumps. The technical problems that an existing submersible pump frequency conversion control device is poor in heat dissipation effect and inconvenient to overhaul are solved. A submersible pump frequency conversion control device comprises a pump assembly, a motor device and a frequency conversion control device, the motor device comprises a cylindrical motor shell and a motor assembly, the frequency conversion control device is arranged on the motor shell, and the frequency conversion control device is provided with a cylindrical shell with a closed containing cavity and a frequency conversion module located in the containing cavity. The shell and the inner wall of the motor shell are in close fit and press fit, the shell is provided with an installation flat plate side wall, the frequency conversion module abuts against the inner side face of the installation flat plate side wall and is detachably and fixedly connected with the installation flat plate side wall, and the closed containing cavity is filled with first cooling oil. According to the utility model, the heat dissipation effect is improved, and detection and maintenance are facilitated.

Description

Technical Field

[0001] The utility model belongs to the technical field of water pumps, in particular to a submersible pump frequency conversion control device. Background Art

[0002] The biggest feature of the submersible pump is that it is a pump that is immersed in water to suck and transport water. It is widely used in farmland irrigation and drainage, industrial and mining enterprises, urban water supply and drainage, and sewage treatment. As the groundwater level continues to drop, the diving depth of the submersible pump is getting deeper and deeper, the water pressure on the motor is getting greater and greater, and the working environment is becoming more and more harsh.

[0003] In the existing technology, submersible pumps generally use ordinary motors and pump bodies. As the diving depth gets deeper, the speed of ordinary motors is low. If a high head is required, the number of impellers in the pump body must be increased. As the number of impellers increases, the efficiency of the water pump will decrease. Therefore, the use of permanent magnet variable frequency motors can increase the speed, reduce the height of the pump body, and make installation more convenient.

[0004] There are also submersible pumps equipped with permanent magnet variable frequency motors in the prior art, but most of them use external variable frequency controllers, separate the variable frequency controller from the motor, and connect the motor with a cable. Due to the high modulation frequency of the variable frequency controller, the cable has distributed inductance, and the motor has distributed capacitance. When the variable frequency controller is working, the cable distributed inductance and the motor distributed capacitance generate a resonant voltage, which affects the motor current and voltage, and in severe cases, the winding will be broken down. The oscillating voltage will generate high-frequency radiation to pollute the electromagnetic spectrum. Due to the distortion of the motor current, the variable frequency controller will be inaccurate in control, and in severe cases, it may even fail to work normally. Therefore, using a built-in frequency converter can solve the side effects caused by the cable.

[0005] However, there are also built-in frequency converters in the prior art, which use epoxy or other methods to seal the frequency converter module. When the water pump is running, the frequency converter heats up, causing the epoxy glue to expand, causing the components to be damaged and fail, shortening the life of the frequency converter, and causing serious direct damage. Due to the poor heat dissipation of epoxy glue, the operating temperature of the components is high, affecting the life of the frequency converter. The frequency converter is directly installed in the inner cavity of the motor. When the water pump is normally filled with water, moisture enters the frequency converter, causing leakage, and in serious cases directly causing damage to the frequency converter. Summary of the invention

[0006] In view of the deficiencies in the prior art, the utility model aims to provide a submersible pump frequency conversion control device.

[0007] The technical problem to be solved by the utility model is: how to better fix the frequency conversion control device and seal it so that it has a good heat dissipation effect and is convenient for later detection and maintenance.

[0008] The purpose of the utility model can be achieved through the following technical solutions: a submersible pump frequency conversion control device, the submersible pump includes a motor device and a frequency conversion control device for driving the pump assembly to work, the motor device includes a cylindrical motor shell and a motor assembly, the frequency conversion control device is arranged in the motor shell and connected to the motor assembly, the frequency conversion control device includes a cylindrical outer shell with a closed accommodating cavity and a frequency conversion module located in the accommodating cavity, the outer shell is tightly fitted and pressed with the inner wall of the motor shell, the outer shell has a mounting plate side wall, the frequency conversion module is against the inner side of the mounting plate side wall and is detachably fixedly connected to the mounting plate side wall, and the closed accommodating cavity of the outer shell is filled with cooling oil.

[0009] Through the above technical solution, the frequency conversion control device is built into the motor shell as a whole and connected to the motor assembly. The connection between the motor assembly and the frequency conversion control device is all in the motor shell, and the frequency conversion module is encapsulated by the shell, which improves the safety of electricity use and avoids electromagnetic interference between the motor assembly and the frequency conversion module; the shell is preferably made of aluminum or aluminum alloy material, because aluminum or aluminum alloy material has good thermal conductivity and is easy to process and form. The frequency conversion module is fixed against the inner side of the side wall of the mounting plate, and the closed accommodating chamber is filled with cooling oil. The cooling oil can better disperse and transfer the heat generated by the frequency conversion control device to the cylindrical shell. After the cylindrical shell and the cylindrical motor shell are tightly fitted and pressed, the heat is transferred from the cylindrical shell to the cylindrical motor shell. The outer periphery of the cylindrical motor shell is all water flow, and the external water flow can effectively take away the heat of the frequency conversion control device. When the frequency conversion control device fails, the cooling oil in the accommodating chamber is poured out, and the detachable frequency conversion module is inspected and repaired. The interaction of the above features allows the frequency conversion module to be firmly fixed on the inner side of the mounting plate side wall and allows the heat generated by the frequency conversion control device to be transferred to the motor housing through the mounting plate side wall, and the external water flow is used to effectively take away the heat of the frequency conversion control device, thereby improving the heat dissipation effect and facilitating detection and maintenance.

[0010] Furthermore, the frequency conversion module includes a power tube and a mounting strip, the side wall of the mounting plate is parallel to the central axis of the shell, and the mounting strip is fastened with the sealing fastening assembly to fix the power tube tightly to the inner surface of the side wall of the mounting plate.

[0011] Through the above technical solution, the power tube is a heating element in the frequency conversion module. After the power tubes are pressed against the side wall of the mounting plate one by one, they are fixed by the mounting strip and the sealing fastening assembly, so that the heat of the power tube can be better transferred to the cylindrical shell and even to the cylindrical motor shell. The side wall of the mounting plate is parallel to the central axis of the shell. The submersible pump is a long cylindrical shape structure so that the longitudinal cross-sectional area of ​​the shell is larger than the transverse cross-sectional area. Therefore, the power tubes can be evenly arranged longitudinally on the side wall of the mounting plate, so that the power tubes have more installation positions and the heat generated by the power tubes can be better transferred.

[0012] Furthermore, the sealing fastening assembly includes a mounting screw and a sealing ring, a plurality of fixing holes 1 are provided on the side wall of the mounting plate, the mounting pressure strip is provided with a threaded hole 1 corresponding to the fixing hole 1, and the mounting screw passes through the sealing ring, the fixing hole 1 and the power tube and is threadedly engaged and fixed with the threaded hole 1. The threaded engagement connects the power tube to the side wall of the mounting plate detachably, and the mounting screw can pass directly through the power tube or between two power tubes. The detachable connection facilitates later maintenance.

[0013] Furthermore, the frequency conversion module also includes a frequency conversion module welded and fixed to the power tube, and the shell also has a large arc-shaped side wall connected end to end to the mounting plate side wall, and the large arc-shaped side wall has an opening with mounting grooves arranged opposite to each other, and the frequency conversion module is snapped into the mounting groove.

[0014] Through the above technical solution, after the frequency conversion module is first clamped in the installation slot for positioning, the installation screws can be conveniently passed through the power tube and screwed and fixed with the installation strip, so that the frequency conversion module will not be displaced during operation.

[0015] Furthermore, the large arc-shaped side wall protrudes inwardly to have a pair of mounting blocks 1 and a pair of mounting blocks 2 that are relatively arranged, and the mounting block 1 and the mounting block 2 are both parallel to the side wall of the mounting plate, and a mounting groove is formed between the mounting block 1 and the mounting block 2, and the frequency conversion module rests on the mounting block 1 and / or the mounting block 2.

[0016] Through the above technical solution, when the frequency conversion module abuts against the mounting block 1 and / or the mounting block 2, the mounting screws can more accurately pass through the power tube and be screwed and fixed with the mounting strip, so that the frequency conversion module does not move during operation.

[0017] Furthermore, the outer shell includes an upper end cover, a lower end cover and a cylindrical body, the cylindrical body includes a mounting plate side wall and a large arc-shaped side wall connected end to end to the mounting plate side wall, the cylindrical body is tightly fitted and pressed against the inner wall of the motor housing, a seal 1 is provided between the upper end cover and the cylindrical body, the upper end cover and the cylindrical body are fixed by a fixing member 1, a seal 2 is provided between the lower end cover and the cylindrical body, the lower end cover and the cylindrical body are fixed by a fixing member 2.

[0018] Through the above technical solution, the upper end cover, the lower end cover, the cylinder, the seal 1, the fixing part 1, the seal 2 and the fixing part 2 together form a closed and sealed shell, and the cooling oil 1 makes the frequency conversion control device as a whole sealed to prevent moisture and other impurities outside the frequency conversion control device from entering.

[0019] Furthermore, the lower part of the upper end cover has an inwardly indented boss 1, a set of the sealing member is arranged outside the boss 1, and the lower part of the boss is embedded in the cylinder, and the upper part of the lower end cover has an inwardly indented boss 2, a set of the sealing member is arranged outside the boss 2, and the upper part of the boss 2 is embedded in the cylinder. The overall sealing performance of the frequency conversion control device is improved to prevent moisture and other impurities outside the frequency conversion control device from entering.

[0020] Furthermore, a cable installation boss protrudes from the upper end cover, a sealing sleeve is arranged inside the cable installation boss, the upper end surface of the cable installation boss is covered with a cable pressure plate, and the cable installation boss, the sealing sleeve and the cable pressure plate are generally penetrated by a wire outlet hole for the cable to pass through.

[0021] Furthermore, the middle of the side wall of the mounting plate is recessed to form an internal wire groove, the internal wire groove is located in the accommodating cavity, the housing further has a small arc-shaped side wall, the middle of the small arc-shaped side wall is connected to the middle of the side wall of the mounting plate, and the two ends of the small arc-shaped side wall and the side wall of the mounting plate form an external wire groove. The internal wire groove and the external wire groove are used to pass the wires.

[0022] Furthermore, an oil filling hole is also provided at the upper end of the shell, and the oil filling hole is sealed and fixed by a screw and a screw sealing gasket.

[0023] Compared with the prior art, the technical effects of the utility model are as follows: the cylindrical shell is tightly fitted and pressed against the inner wall of the cylindrical motor shell, the entire frequency conversion control device is fixed on the inner wall of the motor shell, the frequency conversion module is sealed through the closed accommodating chamber in the cylindrical shell, and cooling oil is injected into the closed accommodating chamber through the oil filling hole to form a closed submersible pump frequency conversion control device as a whole, so that the interior of the frequency conversion control device cannot contact the external environment, thus avoiding water pollution and impurity pollution, greatly increasing the service life, and improving the safety of electricity use; avoiding interference between the motor and the frequency conversion module; and allowing the heat generated during the operation of the frequency conversion module to be completely transferred to the cylindrical shell, so that the frequency conversion module will not be damaged due to external factors, nor will the frequency conversion module be damaged due to overheating due to the inability to completely transfer the dissipated heat, and it is also convenient to disassemble and repair the frequency converter when a fault occurs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The utility model is a cross-sectional view Figure 1 .

[0025] Figure 2 It is an AA enlarged view of the utility model.

[0026] Figure 3 The utility model is a cross-sectional view Figure 2 .

[0027] Figure 4It is a sectional view of the shell of the utility model.

[0028] Figure 5 It is a stereogram of the utility model.

[0029] Figure 6 It is an exploded view of the utility model.

[0030] Description of the figure numbers: 1. Motor housing; 2. Motor assembly; 3. Housing; 30. Cylinder; 301. Installing plate side wall; 301a. Fixing hole 1; 302. Large arc-shaped side wall; 3021. Installing block 1; 3022. Installing block 2; 302a. Installing groove; 303. Small arc-shaped side wall; 31. Upper end cover; 311. Boss 1; 312. Cable installation boss; 32. Lower end cover; 321. Boss 2; 4. Frequency conversion module; 401. Power tube; 4 02, installation strip; 402a, threaded hole 1; 403, frequency conversion module; 404, filter capacitor; 5, cooling oil 1; 6, sealing and fastening assembly; 601, installation screw; 602, sealing ring; 7, seal 1; 8, fixing 1; 9, seal 2; 10, fixing 2; 11, sealing sleeve; 12, cable pressure plate; 13, cable; 14, screw 1; 15, screw sealing gasket; 3a, internal wire duct; 3b, external wire duct; 3c, oil filling hole. DETAILED DESCRIPTION

[0031] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0032] Combination Figures 1 to 3 As shown, a submersible pump frequency conversion control device, wherein the submersible pump includes a motor device and a frequency conversion control device for driving the pump assembly to work, the pump assembly includes a pump body, the pump body is located at the front end of the motor device, the front end of the pump body is provided with a water outlet node, the pump body is connected to the motor assembly 2 and a water inlet node is provided, and the pump body is provided with a plurality of impellers; the motor device is a permanent magnet synchronous motor, the motor device includes a cylindrical motor housing 1 and a motor assembly 2, the motor assembly 2 includes a motor seat, a bearing mounted on the motor seat, an outer stator and an inner rotor and a rotor shaft, when the rotor shaft rotates to drive the impeller to rotate, water can be sucked from the water inlet node, and then transported from the bottom to the top along the pump body, and pumped out from the water outlet node of the pump body. The motor housing 1 also has a motor cavity sealed at both ends, and the motor cavity is filled with cooling oil 2, and the cooling oil 2 is used to transfer heat to the motor assembly 2 and dissipate heat when the motor assembly 2 is working, so the heat generated by the motor assembly 2 will not affect the frequency conversion control device, and the cooling oil 2 can be purchased from the market.

[0033] The frequency conversion control device is arranged in the motor housing 1 and connected to the motor assembly 2. The frequency conversion control device includes a cylindrical housing 3 with a closed accommodating cavity and a frequency conversion module 4 located in the accommodating cavity. The closed accommodating cavity of the housing 3 is filled with cooling oil 1 5. The cooling oil 1 5 can also be purchased from the market. The cooling oil 1 5 and the cooling oil 2 described above can be the same oil or different oils. The cooling oil 1 5 and the cooling oil 2 do not circulate with each other.

[0034] The cylindrical outer shell 3 is tightly fitted and pressed onto the cylindrical motor shell 1, and the motor assembly 2 is also tightly fitted and pressed onto the motor shell 1. The cylindrical motor shell 1 has two outwardly protruding slots, on which pads are placed. The pads limit the motor assembly 2 and the frequency conversion control device, so that the motor assembly 2 and the frequency conversion control device are separated from each other up and down to ensure their normal operation.

[0035] The frequency conversion control device is integrally built into the motor housing 1 and connected to the motor assembly 2. The connection between the motor assembly 2 and the frequency conversion control device is all inside the motor housing 1, and the frequency conversion module 4 is encapsulated by the housing 3, which improves the safety of electricity use and avoids electromagnetic interference between the motor assembly 2 and the frequency conversion module 4.

[0036] Combination Figures 1 to 6 As shown, the shell 3 includes an upper end cover 31, a lower end cover 32 and a cylindrical body 30. The cylindrical body 30 includes a mounting plate side wall 301, a large arc-shaped side wall 302 connected to the mounting plate side wall 301 at both ends, and a small arc-shaped side wall 303 located on the outside of the connecting mounting plate. The cylindrical body 30 is tightly fitted and pressed onto the inner wall of the motor housing 1. The design of the cylindrical body 30 matches the cylindrical shape of the motor housing 1 for better heat dissipation.

[0037] The mounting plate side wall 301 is arranged parallel to the central axis of the outer shell 3, and an internal wire groove 3a is formed in the middle of the mounting plate side wall 301, and the internal wire groove 3a is located in the accommodating cavity. The middle of the small arc-shaped side wall 303 is connected to the middle of the mounting plate side wall 301, and the two ends of the small arc-shaped side wall 303 form an external wire groove 3b with the mounting plate side wall 301. The internal wire groove 3a and the external wire groove 3b are used to pass the motor connecting wires.

[0038] A sealing member 7 is provided between the upper end cover 31 and the cylindrical body 30, and the upper end cover 31 and the cylindrical body 30 are fixed by a fixing member 8. A sealing member 2 9 is provided between the lower end cover 32 and the cylindrical body 30, and the lower end cover 32 and the cylindrical body 30 are fixed by a fixing member 2 10. The housing 3 as a whole forms a closed sealed space to seal the frequency conversion control device as a whole. Since a certain amount of moisture will enter the motor housing 1 during the operation of the motor, the sealed housing 3 prevents moisture and other impurities outside the frequency conversion control device from entering.

[0039] The lower part of the upper end cover 31 has an inwardly indented boss 1 311, the seal 1 7 is sleeved on the outer side of the boss 1 311, and the lower part of the boss 1 311 is embedded in the cylinder 30. The upper part of the lower end cover 32 has an inwardly indented boss 2 321, the seal 2 9 is sleeved on the outer side of the boss 2 321, and the upper part of the boss 2 321 is embedded in the cylinder 30. This method improves the overall sealing of the frequency conversion control device and prevents moisture and other impurities outside the frequency conversion control device from entering.

[0040] A cable 13 mounting boss 312 protrudes from the upper end cover 31, a sealing sleeve 11 is arranged in the cable 13 mounting boss 312, and the upper end surface of the cable 13 mounting boss 312 is covered with a cable 13 pressing plate 12, and the cable 13 mounting boss 312, the sealing sleeve 11 and the cable 13 pressing plate 12 are penetrated by a wire outlet hole for the cable 13 to pass through.

[0041] The upper end of the housing 3 is also provided with an oil filling hole 3c, which is arranged on the upper end cover 31 and is sealed and fixed by a screw 14 and a screw sealing gasket 15.

[0042] Combination Figure 1 and Figure 2 As shown, the frequency conversion module 4 includes a power tube 401, a mounting strip 402, a frequency conversion module 403 and a filter capacitor 404, etc. The power tube 401 and the frequency conversion module 403 are welded and fixed, the frequency conversion module 403 and the filter capacitor 404 are wired and connected, and the frequency conversion module 4 rests on the inner side of the mounting plate side wall 301 and is detachably fixed to the mounting plate side wall 301. The mounting plate side wall 301 is arranged parallel to the central axis of the housing 3, the power tube 401 is a heating element in the frequency conversion module 4, the mounting pressure strip 402 is fastened with the sealing fastening assembly 6 to fix the power tube 401 tightly on the inner surface of the mounting plate side wall 301, and the closed accommodation cavity is filled with cooling oil 5, the cooling oil 5 can better disperse and transfer the heat generated by the frequency conversion control device to the cylindrical housing 3, after the cylindrical housing 3 and the cylindrical motor housing 1 are tightly fitted and pressed, the heat is transferred from the cylindrical housing 3 to the cylindrical motor housing 1, and the outer periphery of the cylindrical motor housing 1 is all water flow, and the external water flow can effectively take away the heat of the frequency conversion control device. When the frequency conversion control device fails, pour out the cooling oil 5 in the accommodation cavity, and then inspect and repair the detachably installed frequency conversion module 4.

[0043] After the power tubes 401 are pressed against the mounting plate side wall 301 one by one, they are fixed through the mounting strip 402 and the sealing and fastening assembly 6, so that the heat of the power tubes 401 can be better transferred to the cylindrical shell 3 and even to the cylindrical motor shell 1. The mounting plate side wall 301 is parallel to the central axis of the shell 3. The submersible pump is a long cylindrical shape structure so that the longitudinal cross-sectional area of ​​the shell 3 is larger than the transverse cross-sectional area. Therefore, the power tubes 401 can be evenly arranged longitudinally on the mounting plate side wall 301, so that the power tubes 401 have more installation positions and the heat generated by the power tubes 401 can be better transferred.

[0044] The filter capacitor 404 is placed on the side of the cylindrical body 30 away from the mounting plate side wall 301, and the frequency conversion module 403 is placed on the side close to the mounting plate side wall 301. The large arc-shaped side wall 302 has a mounting groove 302a with openings arranged opposite to each other, and the frequency conversion module 403 is clamped in the mounting groove 302a. After the frequency conversion module 403 is clamped in the mounting groove 302a for positioning, it is convenient to pass the sealing fastening component 6 through the power tube 401 and screw-thread the mounting pressure strip 402 to fix it, so that the frequency conversion module 403 does not move during operation. Preferably, the large arc-shaped side wall 302 protrudes inwardly with a pair of relatively arranged mounting blocks 1 3021 and a pair of relatively arranged mounting blocks 2 3022, and the mounting blocks 1 3021 and 3022 are both parallel to the mounting plate side wall 301, and the mounting blocks 1 3021 and 3022 form a mounting groove 302a, and the frequency conversion module 403 rests on the mounting blocks 1 3021 and / or 3022.

[0045] The sealing and fastening assembly 6 includes a mounting screw 601 and a sealing ring 602. The mounting plate side wall 301 is provided with a plurality of fixing holes 301a. The mounting pressure strip 402 is provided with a threaded hole 402a corresponding to the fixing hole 301a. The mounting screw 601 passes through the sealing ring 602, the fixing hole 301a and the power tube 401 and then is threadedly engaged and fixed with the threaded hole 402a. The threaded engagement connects the power tube 401 to the mounting plate side wall 301 in a detachable manner. The mounting screw 601 can directly pass through the power tube 401 or pass between two power tubes 401. The detachable connection is convenient for later maintenance.

[0046] The above embodiments are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope defined by the claims of the present invention.

Claims

1. A submersible pump frequency conversion control device, the submersible pump comprising a motor device for driving a pump assembly to work and a frequency conversion control device, the motor device comprising a cylindrical motor housing (1) and a motor assembly (2), characterized in that: The frequency conversion control device is arranged in the motor housing (1) and connected to the motor assembly (2), and comprises a cylindrical housing (3) having a closed accommodating cavity and a frequency conversion module (4) located in the accommodating cavity, the housing (3) being tightly fitted and pressed onto the inner wall of the motor housing (1), the housing (3) having a mounting plate side wall (301), the frequency conversion module (4) being abutted against the inner side surface of the mounting plate side wall (301) and being detachably fixedly connected to the mounting plate side wall (301), and the closed accommodating cavity of the housing (3) being filled with cooling oil (5).

2. A submersible pump frequency conversion control device according to claim 1, characterized in that: The frequency conversion module (4) comprises a power tube (401) and a mounting strip (402); the mounting plate side wall (301) is parallel to the central axis of the housing (3); and the mounting strip (402) is fastened with a sealing fastening assembly (6) to tightly fix the power tube (401) to the inner surface of the mounting plate side wall (301).

3. A submersible pump frequency conversion control device according to claim 2, characterized in that: The sealing and fastening assembly (6) comprises a mounting screw (601) and a sealing ring (602); a plurality of fixing holes (301a) are provided on the side wall (301) of the mounting plate; the mounting pressure strip (402) is provided with a threaded hole (402a) corresponding to the fixing hole (301a); the mounting screw (601) passes through the sealing ring (602), the fixing hole (301a) and the power tube (401) and then is threadedly engaged with the threaded hole (402a) to be fixed.

4. A submersible pump frequency conversion control device according to claim 3, characterized in that: The frequency conversion module (4) also includes a frequency conversion module (403) welded and fixed to the power tube (401), and the housing (3) also includes a large arc-shaped side wall (302) connected end to end to the mounting flat plate side wall (301), and the large arc-shaped side wall (302) has mounting grooves (302a) with openings arranged opposite to each other, and the frequency conversion module (403) is snap-fitted into the mounting grooves (302a).

5. A submersible pump frequency conversion control device according to claim 4, characterized in that: The large arc-shaped side wall (302) protrudes inwardly to have a pair of mounting blocks 1 (3021) and a pair of mounting blocks 2 (3022) arranged opposite to each other, the mounting blocks 1 (3021) and the mounting blocks 2 (3022) are both parallel to the mounting plate side wall (301), a mounting groove (302a) is formed between the mounting blocks 1 (3021) and the mounting blocks 2 (3022), and the frequency conversion module (403) rests on the mounting blocks 1 (3021) and / or the mounting blocks 2 (3022).

6. A submersible pump frequency conversion control device according to any one of claims 1 to 5, characterized in that: The housing (3) comprises an upper end cover (31), a lower end cover (32) and a cylindrical body (30); the cylindrical body (30) comprises a mounting plate side wall (301) and a large arc-shaped side wall (302) connected end to end to the mounting plate side wall (301); the cylindrical body (30) is tightly fitted and press-fitted with the inner wall of the motor housing (1); a sealing member (7) is provided between the upper end cover (31) and the cylindrical body (30); the upper end cover (31) and the cylindrical body (30) are fixed by a fixing member (8); a sealing member (9) is provided between the lower end cover (32) and the cylindrical body (30); the lower end cover (32) and the cylindrical body (30) are fixed by a fixing member (10).

7. A submersible pump frequency conversion control device according to claim 6, characterized in that: The upper end cover (31) has a boss 1 (311) that is indented inwardly at the lower part, the seal 1 (7) is sleeved on the outside of the boss 1 (311), and the lower part of the boss 1 (311) is embedded in the cylindrical body (30), and the lower end cover (32) has a boss 2 (321) that is indented inwardly at the upper part, the seal 2 (9) is sleeved on the outside of the boss 2 (321), and the upper part of the boss 2 (321) is embedded in the cylindrical body (30).

8. A submersible pump frequency conversion control device according to claim 7, characterized in that: A cable installation boss (312) protrudes from the upper portion of the upper end cover (31), a sealing sleeve (11) is arranged inside the cable installation boss (312), the upper end surface of the cable installation boss (312) is covered with a cable pressing plate (12), and the cable installation boss (312), the sealing sleeve (11) and the cable pressing plate (12) are all penetrated by a wire outlet hole for the cable (13) to pass through.

9. A submersible pump frequency conversion control device according to claim 6, characterized in that: The middle of the mounting plate side wall (301) is recessed to form an internal wire groove (3a), and the internal wire groove (3a) is located in the accommodating cavity. The shell (3) also has a small arc-shaped side wall (303), and the middle of the small arc-shaped side wall (303) is connected to the middle of the mounting plate side wall (301), and the two ends of the small arc-shaped side wall (303) form an external wire groove (3b) with the mounting plate side wall (301).

10. A submersible pump frequency conversion control device according to claim 1, characterized in that: The upper end of the housing (3) is also provided with an oil filling hole (3c), and the oil filling hole (3c) is sealed and fixed by a screw (14) and a screw sealing gasket (15).

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