Novel sealing structure of pump shell middle opening face and machining method of novel sealing structure

Abstract

The invention discloses a novel sealing structure of a pump shell split face and a machining method of the novel sealing structure, and relates to the technical field of pump shells, and the novel sealing structure of the pump shell split face comprises a finish machining belt and a sinking area; the finish machining belt is arranged on the side, close to the runner, of the middle opening face and used for being matched with the sealing element to form sealing. The sinking area is located on the middle opening face part outside the finish machining belt, and the casting surface is reserved in the sinking area. The machining method comprises the steps that the pump shell is cast, and the machining allowance of the sinking area is reserved; the finishing strip is subjected to finishing, the finishing being selected from milling or grinding, while retaining the casting surface of the sinker zone. The finish machining belt is arranged on the side close to the flow channel, only a key sealing area is subjected to finish machining, the machining time is remarkably shortened, and tool abrasion is reduced; a casting surface is reserved in the sinking area, secondary machining is not needed, the bolt pre-tightening force requirement is reduced, and therefore the buckling risk of the combination face is reduced, the assembly stability of the pump shell is improved, and the service life of the pump shell is prolonged.

Description

Technical Field

[0001] This invention relates to the field of pump casing technology, and in particular to a novel sealing structure with an open face in a pump casing and its processing method. Background Technology

[0002] In traditional split-case pumps, the split surface (i.e., the mating surface where the pump body splits along the axis) typically requires precision machining of the entire contact surface to ensure sealing performance. However, this full-area precision machining method is time-consuming, leading to rapid tool wear; furthermore, the machining of non-critical areas is less necessary, resulting in redundant material and labor costs; and excessively large contact surfaces require higher bolt preload, which can easily cause deformation of the mating surface, affecting sealing performance and assembly efficiency. Summary of the Invention

[0003] To solve the above-mentioned technical problems, the present invention provides a novel sealing structure with an open face in the pump casing and its processing method, the specific technical solution being as follows:

[0004] A novel sealing structure with a split-face in the pump casing, wherein the pump casing is formed by splitting a pump body along its axis, and a flow channel is provided through the pump body along its axial direction; the novel sealing structure with a split-face in the pump casing includes:

[0005] A finishing strip is disposed on the side of the open face near the flow channel, and the surface roughness of the finishing strip is...

[0006] ≤Ra3.2μm, used to form a seal when used with sealing elements;

[0007] The sunken area is located outside the center section of the finishing zone, and the sunken area retains the casting surface.

[0008] Preferably:

[0009] The width of the finishing strip is 5% to 15% of the flow channel diameter;

[0010] And / or the sinking depth of the sinking area is 3-8 mm;

[0011] And / or the surface roughness of the sunken area is Ra12.5~25μm.

[0012] Preferably, the sealing element is selected from flexible graphite gaskets, metal gaskets, or O-rings.

[0013] The present invention also provides a processing method for processing the novel open-face sealing structure of the pump casing as described in any one of the above claims, the processing method comprising:

[0014] Cast the pump casing, reserving machining allowance for the sinking area;

[0015] The finishing strip is finished by milling or grinding, while preserving the casting surface of the sunken area.

[0016] Preferably, the finishing method is grinding, and the grinding is electrochemical grinding, wherein the electrochemical grinding adopts the following parameters:

[0017] Current density 5–10 A / cm 2 ;

[0018] The electrolyte is a NaNO3 aqueous solution with a mass fraction of 10% to 12%;

[0019] Electrolyte flow rate: 0.5–1.5 m / s;

[0020] The grinding head speed is 1500-2500 rpm.

[0021] Preferably, a variable magnetic field is applied during the electrochemical grinding process, wherein the strength of the variable magnetic field is 0.1 to 0.3 T and the frequency is 0.5 to 2 Hz.

[0022] Preferably, the electrolyte contains 0.01% to 0.3% of a magnetically sensitive material by total mass, wherein the magnetically sensitive material has a particle size of 20 to 100 nm.

[0023] Preferably, the magnetic sensitive material is a surface-coated nano-scale carbonyl iron powder, and the surface coating material is selected from silicon dioxide, alumina, or polyethylene glycol.

[0024] Preferably, the surface-coated nanoscale carbonyl iron powder is prepared by the following steps:

[0025] Nanoscale carbonyl iron powder was prepared by decomposing carbonyl iron compounds via a carbonylation method.

[0026] Under inert gas protection, the nano-scale carbonyl iron powder is dispersed in an organic solvent, and a silica precursor, alumina precursor or polyethylene glycol is added. A coating layer is formed by sol-gel method or chemical precipitation method.

[0027] The coated nano-sized carbonyl iron powder was separated by centrifugation, washed sequentially with ethanol and deionized water to remove unreacted substances, and dried to obtain surface-coated nano-sized carbonyl iron powder.

[0028] Preferably, the method further includes a waste liquid recovery step, the waste liquid recovery step comprising:

[0029] Collect waste liquid generated during electrochemical grinding;

[0030] The waste liquid is passed through a magnetic separator to separate the magnetically sensitive material under a magnetic field strength of 0.5 to 1.0 T;

[0031] The recovered magnetic sensitive material is cleaned, and residual electrolyte on the surface is removed with deionized water and ethanol. After drying, it is reused.

[0032] The remaining waste liquid is neutralized.

[0033] The novel open-face sealing structure for pump casing provided by this invention has the following beneficial effects:

[0034] 1. By setting a finishing strip on the side near the flow channel, finishing is performed only on the critical sealing area, reducing the machining area by 50% to 80% (compared to the traditional full machining surface), significantly shortening the machining time and reducing tool wear.

[0035] 2. The surface roughness of the precision-machined strip is ≤Ra3.2μm, ensuring efficient contact with the sealing element. By utilizing the pressure concentration effect of the narrow contact surface, it achieves sealing performance equivalent to that of traditional fully machined surfaces, avoiding the risk of leakage.

[0036] 3. The sinking area retains the cast surface, eliminating the need for secondary processing and reducing the bolt preload requirement (by up to 20%), thereby reducing the risk of warping at the joint surface and improving the assembly stability and service life of the pump casing.

[0037] 4. The precision-machined strip is designed to be flexible and can be adapted to various sealing elements (such as flexible graphite gaskets, metal gaskets or O-rings) to meet the needs of different working conditions and enhance the versatility of the structure. Attached Figure Description

[0038] 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 recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 A three-dimensional structural schematic diagram of a novel open-face sealing structure for a pump casing provided in an embodiment of the present invention;

[0040] Figure 2 A top view of a novel sealing structure with an open face in the pump casing provided in an embodiment of the present invention.

[0041] Figure Labels

[0042] 10 - Pump casing; 20 - Split surface; 30 - Flow channel;

[0043] 1-Finishing zone; 2-Sinking zone. Detailed Implementation

[0044] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings. The description in this part is only exemplary and explanatory, and should not be used to limit the scope of protection of the present invention in any way.

[0045] It should be noted that similar labels in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0046] It should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use. They 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. Therefore, they should not be construed as limitations on the invention. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0047] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0048] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0049] Please see Figure 1 and Figure 2 This embodiment provides a novel sealing structure with a split face in the pump casing. The pump casing 10 is formed by splitting the split face 20 along the axis of the pump body. A flow channel 30 is provided through the pump body along its axial direction. The novel sealing structure with a split face in the pump casing includes a precision-machined zone 1 and a sinking zone 2.

[0050] The finishing strip 1 is located on the side of the open face 20 near the flow channel 30. The surface roughness of the finishing strip 1 is ≤Ra3.2μm, and it is used to cooperate with the sealing element to form a seal.

[0051] The sunken area 2 is located in the open face 20 outside the finishing zone 1, and the sunken area 2 retains the casting surface.

[0052] The novel open-face sealing structure for the pump casing provided in this embodiment has the following beneficial effects:

[0053] 1. By setting a finishing strip on the side near the flow channel, finishing is performed only on the critical sealing area, reducing the machining area by 50% to 80% (compared to the traditional full machining surface), significantly shortening the machining time and reducing tool wear.

[0054] 2. The surface roughness of the precision-machined strip is ≤Ra3.2μm, ensuring efficient contact with the sealing element. By utilizing the pressure concentration effect of the narrow contact surface, it achieves sealing performance equivalent to that of traditional fully machined surfaces, avoiding the risk of leakage.

[0055] 3. The sinking area retains the cast surface, eliminating the need for secondary processing and reducing the bolt preload requirement (by up to 20%), thereby reducing the risk of warping at the joint surface and improving the assembly stability and service life of the pump casing.

[0056] 4. The precision-machined strip is designed to be flexible and can be adapted to various sealing elements (such as flexible graphite gaskets, metal gaskets or O-rings) to meet the needs of different working conditions and enhance the versatility of the structure.

[0057] Furthermore:

[0058] The width of the finishing strip 1 is 5% to 15% of the diameter of the flow channel 30; preferably in the range of 10 to 30 mm.

[0059] And / or the sinking depth of sinking zone 2 is 3-8 mm.

[0060] The surface roughness of the subsidence zone 2 is Ra12.5~25μm.

[0061] Furthermore, the sealing element is selected from flexible graphite gaskets, metal gaskets, or O-rings.

[0062] This embodiment also provides a processing method for processing the novel open-face sealing structure of the pump casing as described in any of the above embodiments. The processing method includes:

[0063] Step 1. Cast the pump casing 10, leaving a machining allowance for the sinking zone 2.

[0064] Step 2. Perform finishing on the finishing zone 1. The finishing method is selected from milling or grinding, while preserving the casting surface of the sinking zone 2.

[0065] The processing method provided in this embodiment has the following beneficial effects:

[0066] 1. By milling or grinding only the finishing strip, the machining area is reduced by 50% to 80%, significantly shortening the machining time and reducing tool wear.

[0067] 2. During casting, a machining allowance is reserved for the sinking area, and the sinking area retains the casting surface, eliminating the need for secondary machining, simplifying the process and improving production efficiency.

[0068] 3. The surface roughness of the finished annular strip is ≤Ra3.2μm, ensuring efficient contact with the sealing element. The narrow contact surface achieves pressure concentration, forming a reliable seal, which is equivalent to the sealing effect of a traditional fully machined surface.

[0069] 4. Since only critical areas are machined, the bolt preload requirement can be reduced by 20% (compared to traditional full-machined surfaces), which reduces the risk of deformation of the mating surfaces during assembly, and improves assembly efficiency and the structural stability of the pump casing.

[0070] Furthermore, the finishing method is grinding, specifically electrochemical grinding, which employs the following parameters:

[0071] Current density 5–10 A / cm 2 .

[0072] The electrolyte is a NaNO3 aqueous solution with a mass fraction of 10% to 12%.

[0073] Electrolyte flow rate: 0.5–1.5 m / s.

[0074] The grinding head speed is 1500-2500 rpm.

[0075] Electrochemical grinding is a hybrid processing technology that combines electrochemical dissolution and mechanical grinding. Specified parameters ensure high surface quality of the annular precision-machined belt. Electrochemical grinding removes material through electrochemical action, and combined with mechanical grinding, the surface roughness can reach ≤Ra1.6μm, improving the fit between the precision-machined belt and the sealing element and enhancing the sealing performance.

[0076] Furthermore, a variable magnetic field is applied during the electrochemical grinding process, with an intensity of 0.1–0.3 T and a frequency of 0.5–2 Hz.

[0077] The variable magnetic field can be generated by an electromagnetic coil, and the Lorentz force can be used to regulate the flow of ions in the electrolyte, optimize the uniformity of the electrochemical reaction, thereby reducing local current density unevenness and stabilizing the surface roughness below Ra1.6μm, thus improving flatness.

[0078] Furthermore, 0.01% to 0.3% of a magnetically sensitive material by total mass is added to the electrolyte, and the particle size of the magnetically sensitive material is 20 to 100 nm.

[0079] Among them, the magnetic sensitive material can form a chain structure under the action of a variable magnetic field, which further optimizes the electrolyte flow trajectory and enhances the efficiency of electrochemical reaction.

[0080] Furthermore, the magnetic sensitive material is a surface-coated nano-scale carbonyl iron powder, and the surface coating material is selected from silicon dioxide, alumina or polyethylene glycol to improve chemical stability and prevent particle oxidation or agglomeration.

[0081] Furthermore, the surface-coated nanoscale carbonyl iron powder is prepared through the following steps:

[0082] Step 1. Prepare nano-sized carbonyl iron powder by decomposing carbonyl iron compounds via the carbonylation method.

[0083] Step 2. Under inert gas protection, disperse nano-sized carbonyl iron powder in an organic solvent, add silica precursor, alumina precursor or polyethylene glycol, and form a coating layer using sol-gel method or chemical precipitation method.

[0084] Step 3. The coated nano-sized carbonyl iron powder is separated by centrifugation, washed sequentially with ethanol and deionized water to remove unreacted substances, and dried to obtain surface-coated nano-sized carbonyl iron powder.

[0085] Among them, the silica precursor can be tetraethoxysilane, methyl orthosilicate, etc., with tetraethoxysilane being preferred; the alumina precursor can be aluminum isopropoxide and aluminum chloride, etc., with aluminum isopropoxide being preferred.

[0086] Furthermore, it also includes a waste liquid recovery step, which includes:

[0087] Step 1. Collect the waste liquid generated by electrochemical grinding.

[0088] Step 2. Pass the waste liquid through a magnetic separator to separate the magnetic sensitive material under a magnetic field strength of 0.5 to 1.0 T.

[0089] Step 3. Clean the recovered magnetic sensitive material, remove residual electrolyte from the surface with deionized water and ethanol, and reuse it after drying.

[0090] Step 4. Neutralize the remaining waste liquid.

[0091] Specific embodiments are provided below. These embodiments are intended to enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way.

[0092] Example 1

[0093] The pump casing is made of gray cast iron, with a flow channel diameter of 200mm. The casting mold design includes a 5mm allowance for the settling zone. A CNC surface grinder equipped with a diamond wheel (120# grit) is used. The machining area is a finishing zone with a width of 20mm.

[0094] Fix the pump housing to the grinding machine table and adjust the grinding wheel to align with the finishing zone. Set the grinding parameters: grinding wheel speed 2000 rpm, feed rate 0.5 mm / min, and water-based emulsion coolant. Grind until the surface roughness is ≤ Ra 3.2 μm, and measure the width and roughness. Preserve the cast surface of the sunken area.

[0095] A flexible graphite gasket (1 mm thick) is laid on the finishing strip. M12 bolts are used for assembly, with a preload set to approximately 30 kN.

[0096] The surface roughness of the finished strip was measured using a surface roughness meter. The width of the finished strip and the depth of the recess were measured using a coordinate measuring machine. A sealing performance test was performed (water pressure 0.5 MPa, 30 minutes). The machining time and tool wear were recorded.

[0097] The test data is as follows:

[0098] Finished strip width: 20.1±0.2mm. Surface roughness: Ra3.0μm.

[0099] Depth of the sunken area: 5.0±0.1mm. Surface roughness: Ra24.8μm.

[0100] Processing time: 15 minutes / piece (40% shorter than 25 minutes for full surface processing).

[0101] Grinding wheel wear: minor.

[0102] Water pressure test: No leakage at 0.5MPa, sealing performance is equivalent to the entire machined surface.

[0103] Bolt preload: approximately 30kN, compared to 37.5kN for conventional fully machined surfaces, representing a 20% reduction.

[0104] Deformation of the mating surface: No obvious warping (CMM detected deformation <0.05mm).

[0105] Example 1 achieves a surface roughness of Ra3.0μm through mechanical grinding, meeting sealing requirements, reducing the processing area by 60%, shortening the processing time by 40%, and reducing the bolt preload by 20%.

[0106] Example 2

[0107] The pump casing is made of gray cast iron, with a flow channel diameter of 200mm. The casting mold design includes a 5mm allowance for the settling area.

[0108] Electrolyte preparation: 11% NaNO3 aqueous solution (mass fraction), prepared with deionized water, pH value 7.0-7.2.

[0109] The electrochemical grinding equipment uses a self-made electrolytic cell and is equipped with a diamond grinding head (cathode, grit size 150#), with the pump casing fixed as the anode.

[0110] The power supply uses a DC power supply (output current 0-100A, voltage 0-30V).

[0111] The electrolyte circulation system uses a peristaltic pump, with the flow rate controlled at 1 m / s.

[0112] Fix the pump casing inside the electrolytic cell, adjust the grinding head to align with the finishing strip, and ensure a machining width of 20mm.

[0113] Electrochemical grinding parameters: Current density 8A / cm² 2 The electrolyte flow rate is 1 m / s, the circulation system ensures uniform flow, and the grinding head speed is 2000 rpm.

[0114] Power on and start the grinding head, and process until the surface roughness is ≤Ra1.6μm, with a processing time of approximately 12 minutes. Preserve the cast surface of the sunken area. After processing, rinse the pump housing with deionized water and blow dry.

[0115] A flexible graphite gasket (1 mm thick) is laid on the finishing strip. M12 bolts are used for assembly, with a preload set to approximately 29.3 kN.

[0116] The surface roughness of the finished strip was measured using a surface roughness meter.

[0117] The width of the finishing strip and the depth of the sinking zone were measured using a coordinate measuring machine.

[0118] Conduct a sealing performance test (water pressure 0.5MPa, 30 minutes).

[0119] Record processing time, energy consumption, and grinding head wear.

[0120] The test data is as follows:

[0121] Finished strip width: 20.0±0.15mm. Surface roughness: Ra1.55μm.

[0122] Depth of the sunken area: 5.0±0.1mm. Surface roughness: Ra24.7μm.

[0123] Processing time: 12 minutes / piece.

[0124] Energy consumption: approximately 0.8 kWh / unit.

[0125] Grinding head wear: slight.

[0126] Water pressure test: No leakage at 0.5MPa, excellent sealing performance, equivalent to the entire machined surface.

[0127] Bolt preload: approximately 29.3 kN, a reduction of approximately 22%.

[0128] Deformation of the mating surface: CMM detected deformation <0.03mm.

[0129] Example 2 achieves a surface roughness of Ra 1.55 μm through electrochemical grinding, reducing processing time by 20%. Bolt preload is reduced by 22%, mating surface deformation is reduced, and sealing performance is equivalent to that of the entire machined surface.

[0130] Example 3

[0131] The pump casing is made of gray cast iron, with a flow channel diameter of 200mm. The casting mold design includes a 5mm allowance for the settling area.

[0132] Electrolyte preparation: 11% NaNO3 aqueous solution, prepared with deionized water, pH 7.0–7.2.

[0133] The magnetic sensitive material is selected from nano-sized carbonyl iron powder (particle size 50nm), with a mass fraction of 0.2%, and is added to the electrolyte by ultrasonic dispersion.

[0134] The electrochemical grinding equipment uses a self-made electrolytic cell equipped with a diamond grinding head (cathode, 150# grit), with the pump casing fixed as the anode. A DC power supply is used (output current 0–100A, voltage 0–30V). The electrolyte circulation system uses a peristaltic pump, controlling the flow rate at 1 m / s. The magnetic field device uses an electromagnetic coil, set at an intensity of 0.2T and a frequency of 1 Hz.

[0135] Fix the pump casing inside the electrolytic cell, adjust the grinding head to align with the finishing strip, and ensure a machining width of 20mm.

[0136] Prepare the electrolyte by adding 0.2% nano-sized carbonyl iron powder and ultrasonically dispersing for 10 minutes to ensure uniformity.

[0137] Set the electrochemical grinding parameters:

[0138] Current density: 8A / cm 2 .

[0139] Electrolyte flow rate: 1 m / s.

[0140] Grinding head speed: 2000 rpm.

[0141] Start the electromagnetic coil, apply a variable magnetic field (0.2T, 1Hz), energize and start the grinding head, and process until the surface roughness is ≤Ra1.5μm, with a processing time of approximately 11 minutes. Preserve the cast surface of the sunken area.

[0142] After processing, rinse the pump casing with deionized water and blow it dry.

[0143] A flexible graphite gasket (1 mm thick) is laid on the finishing strip. M12 bolts are used for assembly, with a preload set to approximately 28.1 kN.

[0144] The surface roughness of the finished strip was measured using a surface roughness meter.

[0145] The width of the finishing strip and the depth of the sinking zone were measured using a coordinate measuring machine.

[0146] Conduct a sealing performance test (water pressure 0.5MPa, 30 minutes).

[0147] Record processing time, energy consumption (power supply), grinding head wear, and electrolyte stability.

[0148] The test data are as follows: Finished strip width: 20.0±0.12mm; Surface roughness: Ra1.48μm.

[0149] Depth of the sunken area: 5.0±0.1mm. Surface roughness: Ra24.6μm.

[0150] Processing time: 11 minutes / piece.

[0151] Energy consumption: approximately 0.75 kWh / unit.

[0152] Grinding head wear: slight.

[0153] Water pressure test: No leakage at 0.5MPa, excellent sealing performance, equivalent to the entire machined surface.

[0154] Bolt preload: approximately 28.1 kN, a reduction of 25%.

[0155] Deformation of the mating surface: CMM detected deformation <0.02mm.

[0156] Electrolyte stability: pH value decreased slightly after processing (7.0→6.8), and particle deposition slightly agglomerated (a small amount of deposition at the bottom of the electrolytic cell).

[0157] Example 3 achieved a surface roughness of Ra 1.48 μm in the finished band by combining electrochemical grinding with a variable magnetic field and nano-scale carbonyl iron powder, reducing processing time by 26.7% and energy consumption by 12%. Bolt preload was reduced by 25%, and the deformation of the mating surface was further reduced (<0.02 mm), with sealing performance equivalent to the entire machined surface.

[0158] Example 4

[0159] The pump casing is made of gray cast iron, with a flow channel diameter of 200mm. The casting mold design includes a 5mm allowance for the settling area.

[0160] Electrolyte preparation: 11% NaNO3 aqueous solution (mass fraction), prepared with deionized water, pH value 7.0-7.2.

[0161] The magnetic sensitive material was prepared using SiO2-coated nano-sized carbonyl iron powder (70 nm particle size) with a mass fraction of 0.2%, through the following steps:

[0162] Carbonyl iron compound (Fe(CO)5) was decomposed and carbonyl iron powder with a particle size of 50-70 nm was prepared at 300℃ and 2MPa.

[0163] Under nitrogen protection, carbonyl iron powder was dispersed in ethanol (mass ratio 1:10), TEOS (TEOS:ethanol volume ratio 1:6) was added, 0.2 mol / L ammonia water was added dropwise, and the mixture was stirred for 4 hours (pH 3-4) to form a SiO2 coating layer.

[0164] Centrifuge (8000 rpm, 10 minutes), wash three times each with ethanol and deionized water, and vacuum dry at 80°C for 2 hours to obtain SiO2-coated carbonyl iron powder.

[0165] After the magnetic sensitive material is added to the electrolyte, it is ultrasonically dispersed for 10 minutes to ensure uniformity.

[0166] The electrochemical grinding equipment uses a self-made electrolytic cell and is equipped with a diamond grinding head (cathode, grit size 150#), with the pump casing fixed as the anode.

[0167] The power supply should be a DC power supply (output current 0-100A, voltage 0-30V).

[0168] The electrolyte circulation system uses a peristaltic pump, with the flow rate controlled at 1 m / s.

[0169] The magnetic field device uses an electromagnetic coil with a strength of 0.2T and a frequency of 1Hz.

[0170] Fix the pump casing inside the electrolytic cell, adjust the grinding head to align with the finishing strip, and ensure a machining width of 20mm.

[0171] Prepare the electrolyte by adding 0.2% SiO2-coated carbonyl iron powder and ultrasonically dispersing for 10 minutes.

[0172] Set the electrochemical grinding parameters:

[0173] Current density: 8A / cm 2 .

[0174] Electrolyte flow rate: 1 m / s.

[0175] Grinding head speed: 2000 rpm.

[0176] Start the electromagnetic coil, apply a variable magnetic field (0.2T, 1Hz), energize and start the grinding head, and machine until the surface roughness is ≤Ra1.5μm, the machining time is about 11 minutes. Preserve the cast surface of the sunken area. After machining, rinse the pump housing with deionized water and blow dry.

[0177] A flexible graphite gasket (1 mm thick) is laid on the finishing strip. M12 bolts are used for assembly, with a preload set to approximately 28.1 kN.

[0178] The surface roughness of the finished strip was measured using a surface roughness meter.

[0179] The width of the finishing strip and the depth of the sinking zone were measured using a coordinate measuring machine.

[0180] Conduct a sealing performance test (water pressure 0.5MPa, 30 minutes).

[0181] Record processing time, energy consumption, grinding head wear, and electrolyte stability.

[0182] The test data is as follows:

[0183] Finished strip width: 20.0±0.10mm. Surface roughness: Ra1.47μm.

[0184] Depth of the sunken area: 5.0±0.1mm. Surface roughness: Ra24.6μm.

[0185] Processing time: 11 minutes / piece.

[0186] Energy consumption: approximately 0.74 kWh / unit.

[0187] Grinding head wear: Very slight.

[0188] Water pressure test: No leakage at 0.5MPa, excellent sealing performance, equivalent to the entire machined surface.

[0189] Bolt preload: approximately 28.1 kN, compared to 37.5 kN for conventional fully machined surfaces, a reduction of 25%.

[0190] Deformation of the mating surface: CMM detected deformation <0.015mm.

[0191] Electrolyte stability: pH value remained stable before and after processing (7.0–7.1) with no significant change. No obvious agglomeration or deposition (no residue at the bottom of the electrolytic cell).

[0192] Example 4 demonstrates how electrochemical grinding combined with a variable magnetic field and SiO2-coated nano-carbonyl iron powder achieves a surface roughness of Ra 1.47 μm in the finished band, reducing processing time by 26.7% and energy consumption by 13%. Bolt preload is reduced by 25%, and deformation of the mating surface is further reduced (<0.015 mm), resulting in sealing performance equivalent to the entire machined surface.

[0193] Example 5

[0194] After the electrochemical grinding in Example 4 was completed, approximately 10 L of waste liquid discharged from the electrolytic cell was collected. The initial pH of the waste liquid was 7.0–7.2.

[0195] The waste liquid is passed through a high-gradient magnetic separator, where a magnetic field of 0.8T is applied, and SiO2-coated carbonyl iron powder is adsorbed onto the filter screen of the magnetic separator.

[0196] Collect the adsorbed carbonyl iron powder and record the recovery quality.

[0197] The recovered carbonyl iron powder was placed in a cleaning tank and rinsed first with deionized water (5L, 3 times), and then with ethanol (2L, 3 times) to remove residual NaNO3 and impurities.

[0198] Drying in a vacuum drying oven at 80℃ for 2 hours yields dried SiO2-coated carbonyl iron powder.

[0199] The remaining waste liquid, approximately 9.8 L, was collected and titrated with 0.1 mol / L NaOH solution to adjust the pH to 7.2.

[0200] The recovered carbonyl iron powder was re-added to an 11% NaNO3 electrolyte and subjected to electrochemical grinding tests (with the same parameters as in Example 4). The surface roughness and sealing performance of the finished strip were then tested.

[0201] Weigh the recovered carbonyl iron powder and calculate the recovery rate.

[0202] Evaluate the performance stability of the recycled particles during reprocessing.

[0203] The pH of the neutralized waste liquid was measured using a pH meter.

[0204] After reusing the recycled granules, the roughness and sealing performance of the finished belt were measured.

[0205] The test data is as follows:

[0206] Waste liquid volume: 10L / piece.

[0207] Recovery weight: 19.2g (recovery rate 96%).

[0208] Electrolyte stability: pH remains stable (7.0-7.1) after repeated use, with no deposition or aggregation.

[0209] Repeated processing effect: Finished band roughness: Ra1.49μm.

[0210] No leakage was observed during the water pressure test (0.5MPa, 30 minutes), which is equivalent to the entire machined surface.

[0211] Processing time: 11 minutes / piece.

[0212] Example 5, based on the electrochemical grinding process of Example 4, utilizes a high-gradient magnetic separator to recover SiO2-coated nanoscale carbonyl iron powder. After neutralization, the pH of the waste liquid stabilizes at 7.2, meeting environmental standards. The recovered particles are reused, maintaining stable processing quality (roughness Ra 1.49 μm, leak-free sealing performance), with processing time and energy consumption consistent with Example 4. This waste liquid recovery process can reduce material costs by 20% and processing costs by 20%, achieving the goal of green manufacturing.

[0213] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0214] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. The above are only preferred embodiments of the present invention. It should be noted that due to the limitations of textual expression, and the objective existence of infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other occasions without modification, should all be considered within the scope of protection of the present invention.

Claims

1. A novel sealing structure with a split-face in a pump casing, wherein the pump casing (10) is formed by splitting a split-face (20) along the axis of the pump body, and a flow channel (30) is provided through the pump body along its axial direction, characterized in that, The novel open-face sealing structure in the pump casing includes: A finishing strip (1) is disposed on the side of the open face (20) near the flow channel (30), and the surface roughness of the finishing strip (1) is ≤Ra3.2μm, which is used to cooperate with the sealing element to form a seal; The sunken area (2) is located outside the center face (20) portion of the finishing zone (1), and the sunken area (2) retains the casting surface.

2. The novel sealing structure with an open face in the pump casing according to claim 1, characterized in that: The width of the finishing strip (1) is 5% to 15% of the diameter of the flow channel (30); And / or the sinking depth of the sinking area (2) is 3-8 mm; And / or the surface roughness of the sunken area (2) is Ra12.5~25μm.

3. The novel sealing structure with an open face in the pump casing according to claim 1, characterized in that, The sealing element is selected from flexible graphite gaskets, metal gaskets, or O-rings.

4. A processing method for processing the novel open-face sealing structure of a pump casing as described in any one of claims 1 to 3, characterized in that, The processing method includes: Cast pump casing (10), with machining allowance reserved for the sinking area (2); The finishing strip (1) is finished by milling or grinding, while the casting surface of the sinking area (2) is preserved.

5. The processing method according to claim 4, characterized in that, The finishing method is grinding, and the grinding is electrochemical grinding, which uses the following parameters: Current density 5–10 A / cm 2 ; The electrolyte is a NaNO3 aqueous solution with a mass fraction of 10% to 12%; Electrolyte flow rate: 0.5–1.5 m / s; The grinding head speed is 1500-2500 rpm.

6. The processing method according to claim 5, characterized in that, A variable magnetic field is applied during the electrochemical grinding process. The strength of the variable magnetic field is 0.1 to 0.3 T, and the frequency is 0.5 to 2 Hz.

7. The processing method according to claim 6, characterized in that, The electrolyte contains 0.01% to 0.3% of a magnetically sensitive material by mass, the magnetically sensitive material having a particle size of 20 to 100 nm.

8. The processing method according to claim 7, characterized in that, The magnetic sensitive material is a surface-coated nano-scale carbonyl iron powder, and the surface coating material is selected from silicon dioxide, alumina, or polyethylene glycol.

9. The processing method according to claim 8, characterized in that, The surface-coated nanoscale carbonyl iron powder is prepared by the following steps: Nanoscale carbonyl iron powder was prepared by decomposing carbonyl iron compounds via a carbonylation method. Under inert gas protection, the nano-scale carbonyl iron powder is dispersed in an organic solvent, and a silica precursor, alumina precursor or polyethylene glycol is added. A coating layer is formed by sol-gel method or chemical precipitation method. The coated nano-sized carbonyl iron powder was separated by centrifugation, washed sequentially with ethanol and deionized water to remove unreacted substances, and dried to obtain surface-coated nano-sized carbonyl iron powder.

10. The processing method according to claims 7-9, characterized in that, It also includes a waste liquid recovery step, which includes: Collect waste liquid generated during electrochemical grinding; The waste liquid is passed through a magnetic separator to separate the magnetically sensitive material under a magnetic field strength of 0.5 to 1.0 T; The recovered magnetic sensitive material is cleaned, and residual electrolyte on the surface is removed with deionized water and ethanol. After drying, it is reused. The remaining waste liquid is neutralized.

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