A long-life multistage split pump

Abstract

The application discloses a multi-stage middle-open pump with a long service life, which comprises a pump body, wherein a driving side mechanical seal chamber, a first-stage suction chamber, an inducer chamber, a plurality of positive impeller chambers, an impeller pressure relief chamber, a plurality of reverse impeller chambers, a secondary suction chamber, a mechanical seal pressure relief chamber and a high-pressure side mechanical seal chamber are sequentially arranged along a driving end to a high-pressure end of the pump body; an upper end of a last-stage positive impeller chamber is communicated with an upper end of the secondary suction chamber through a pump cover transition channel; a lower end of the last-stage positive impeller chamber is communicated with a lower end of the secondary suction chamber through a pump body transition channel; the impeller pressure relief chamber is communicated with a penultimate positive impeller chamber through a first pressure relief pipeline; and the mechanical seal pressure relief chamber is communicated with the first-stage positive impeller chamber through a second pressure relief pipeline. The pump can eliminate the axial force generated by the impeller during operation, eliminate the radial force generated by high and low pressure liquid in the impeller cavity on the impeller during operation, eliminate the axial stress vibration and the radial stress vibration of the rotor assembly, ensure the stable and reliable operation of the pump, and prolong the operation and service life of the pump.

Description

Technical Field

[0001] This invention belongs to the field of pump technology, specifically relating to a multi-stage split-case pump with a long lifespan. Background Technology

[0002] Multistage split-case pumps are special centrifugal pumps with multiple impeller stages and extremely high heads. Their flow rates reach 5000 m³ / h and above, heads reach 4000 m and above, speeds range from 3000 r / min to 10000 r / min, and power outputs reach 20000 kW and above. They are used in large-scale seawater desalination projects, large-scale coal mining projects, large-scale oilfield water injection projects, large-scale long-distance oil transportation projects, high-pressure pipeline transportation processes in refineries, high-pressure feedwater projects for power plant boilers, LNG cryogenic high-pressure liquid transportation projects, and high-pressure dephosphorization systems in steel plants, among other special heavy-duty industrial applications. These applications cannot be replaced by general split-case or multistage centrifugal pumps. Therefore, the stability, reliability, and safety of multistage split-case pump operation are crucial. Due to the special application areas, the design, development, manufacturing, use, maintenance, and component interchangeability of multistage split-case pumps are also very important; in other words, a long pump lifespan is essential.

[0003] In a spiral volute compression chamber, when the flow coordination between the compression chamber and the impeller is disrupted—that is, when the pump's operating flow rate is less than or greater than the design rated flow rate due to some reason (changes in the operating pressure of the pipeline system, changes in the demand flow rate at the end of the system, changes in the frequency of the power grid, changes in the pump inlet pipeline system head, pump drive system stall or overspeed, etc.)—a sharp contradiction arises between the operating flow rate and the design rated flow rate. This disrupts the condition of symmetrical pressure distribution along the impeller axis within the spiral volute compression chamber. The high and low pressure liquids within the spiral volute compression chamber act on the impeller blades and outer circumference, generating radial force. This radial force is transmitted through the impeller to the pump shaft, causing alternating stress on the pump bearings and resulting in directional deflection. This radial force is then transmitted through the pump shaft to the bearings and acts on the bearing housing, pump body, and pump cover, causing large vibrations in the pump rotor, bearings, and pump body. This damages components such as the pump shaft, bearings, mechanical seals, and impeller, shortening the overall service life of the pump. In existing technologies, the impeller compression chamber of split-case pumps is either a single-channel or double-channel spiral volute compression chamber structure. A single-channel spiral volute compression chamber cannot eliminate the radial force on the pump rotor, while a double-channel spiral volute compression chamber can eliminate most of the radial force but not completely. Because multi-stage split-case pumps have a large number of impeller stages, the resulting radial force is significant. Furthermore, due to the large number of impeller stages, there are also numerous interstage compression and suction chambers. In addition, casting errors in the pump body and cover can cause the flow channel dimensions of the compression and suction chambers to deviate from the design values. Therefore, the radial force acting on the pump shaft alternates multiple times, subjecting the pump bearings to multiple bending stresses and various alternating forces. Shear stress causes irregular and chaotic disturbances and deformations in the pump shaft. These forces and deformations cause friction between the rotating and non-rotating components of the pump, resulting in damage and pump vibration. This frictional vibration causes the pump to generate significant noise during operation, severely affecting the working environment. At the same time, frictional vibration causes severe vibration and shaking of the pump set, loosening of bolts or connections in the pump and pump set, leading to leakage of the conveyed medium or serious damage to the pump set, causing major accidents. Because the friction between the rotating and non-rotating parts of the pump generates multiple frictional stresses, these forces act on the pump shaft and are superimposed with the radial force of the pump rotor, causing the pump bearing to be subjected to greater multiple bending stresses and various alternating shear stresses, resulting in damage to the pump shaft.Furthermore, in multi-stage split-case pumps, the interstage impeller sump chamber, interstage impeller suction chamber, and final stage secondary impeller sump chamber are single-channel or double-channel spiral volute structures. Neither the sump chamber nor the suction chamber has volute guide vanes. When the impeller rotates at high speed in the sump chamber and suction chamber to convert mechanical energy into pressure energy for hydraulic action, pressure fluctuations and pressure vortices occur within the volute flow channel due to the uneven cross-sectional area and shape and the lack of volute guide vanes. Since there are no volute guide vanes to eliminate or balance these pressure fluctuations and vortices, they cause impeller vibration and vortex excitation. These vibrations are transmitted to the pump through the main shaft, increasing the pump's operating noise. Increased vibration, along with pressure fluctuations and pressure vortices, creates high and low pressure differences in the pressure chamber and suction chamber. These pressure differences lead to interstage cavitation in the pressure chambers of the interstage impellers, the suction chambers of the interstage impellers, and the pressure chambers of the final stage secondary impellers. Cavitation generates bubbles that block the interstage flow channels and impeller flow channels, preventing the impellers from performing energy conversion efficiently. This results in low pump efficiency and wasted energy. Furthermore, the bubbles generated by interstage cavitation can explode during medium flow, exacerbating pump operating noise and vibration. They can also cause radial displacement of the impeller, generating radial force and causing radial bending deformation of the pump shaft. This results in rapid cavitation damage to the pump's flow components, severely shortening the pump's service life and reliability.

[0004] Because of the suction inlet, the radial area of ​​the impeller front cover plate is smaller than that of the impeller rear cover plate. This area is exactly the radial area of ​​the impeller suction inlet. When the pump is running, the pressure at the impeller suction inlet is less than the pressure at the impeller rear cover plate, so the pump generates axial force during operation. The split-case pump uses multiple impellers connected in series to superimpose the impeller head to achieve a high head.In existing technologies, due to the operating parameters of the pump, the impellers are asymmetrically distributed on the pump shaft. This causes axial forces to be generated in the impellers during pump operation. Furthermore, due to the special structure of split-case pumps, a significant pressure difference exists between the impeller chambers of the last-stage forward impeller and the last-stage reverse impeller. These two impeller chambers are directly connected by a hub clearance. Because the hub clearance does not completely impede and reduce the pressure of the liquid in the pressure difference, a huge axial force is generated between the last-stage forward and reverse impellers. Sometimes, this axial force can reach tens of tons or even higher. This axial force acts on the last-stage forward impeller, causing axial movement of the pump rotor. In this case, a sliding thrust disc mechanism must be used to withstand the force. Axial force, pump bearings are subjected to enormous axial tensile stress, and the sliding thrust disc is subjected to heavy loads and high-speed rotational friction for a long time, making it prone to overheating and wear damage. Furthermore, the sliding thrust disc mechanism is complex and costly, and the maintenance process is complicated. When the pump's operating pressure fluctuates due to various reasons (changes in pipeline system operating pressure, changes in the flow demand at the end of the system, changes in the power grid frequency, changes in the pump inlet pipeline system head, pump drive system stall or overspeed, etc.), the axial force also fluctuates, causing the pump rotor to move axially left and right dynamically, leading to friction on the sliding thrust disc. This causes disc-shaped vibration of the rotor, resulting in a significant increase in pump vibration, and the pump bearings are subjected to axial tensile stress and compressive stress. Forces cause friction damage to pump bearings and bushings. Severe friction can lead to axial seizure and jamming of the sliding thrust disc, resulting in shaft breakage. Lateral movement of the pump rotor alters the mechanical seal's compression ratio; a low compression ratio causes leakage, while a high ratio can cause it to burn out due to excessive friction. During operation, continuous and overlapping axial and radial forces act on the pump shaft, subjecting the pump bearings to multiple alternating stresses—a combination of axial tensile, compressive, bending, and alternating shear stresses. This causes axial and radial friction between rotating and non-rotating components, damaging bushings, mechanical seals, bearings, impellers, bearing housings, and the pump shaft. Increased operating noise and vibration during pump startup, accompanied by various chaotic and miscellaneous vibration spectra that cannot be eliminated or adjusted to achieve spectral balance, exacerbate the potential risks of leaks in the pump and pump set, leading to leakage of the conveyed medium or serious damage to the pump set and causing major accidents. The continuous and overlapping action of axial and radial forces on the pump shaft accelerates the damage rate of the pump shaft. In severe cases, the pump shaft may undergo multiple alternating fatigue fractures, causing the pump set to stop operating, resulting in serious accidents and irreparable huge losses. This significantly reduces the pump's operational stability, reliability, and safety, shortens the pump's operating and service life, and increases the operating, inspection, and maintenance costs of the pump set.

[0005] The defects of split-case pumps, such as high vibration, noise, and main shaft breakage, are caused not only by axial and radial forces, but also by the mechanical imbalance of the pump rotor assembly and the hydraulic imbalance during pump operation. In the existing technology, the impeller cavity ring of the pump is an integral structure, which cannot be installed independently on the pump body and pump cover, but is fitted onto the impeller cavity ring and installed in conjunction with the pump body and pump cover. When performing dynamic balancing tests on the pump rotor assembly, it is necessary to install the impeller on the main shaft to complete the dynamic balancing test, and then disassemble the impeller, key bar, impeller stage bushing, etc., and reinstall the impeller, key bar, impeller cavity ring, etc. on the main shaft to form the rotor assembly. Assembly, disassembly, and reassembly can cause rotor imbalance and secondary damage to parts, affecting assembly accuracy. This prevents the rotor assembly from achieving overall dynamic balancing, resulting in imbalance defects. When the rotor rotates at high speed, this imbalance causes significant rotor vibration. The force generated by this vibration acts on the main shaft, causing it to bend and deform, leading to increased pump noise and vibration. Furthermore, since the impeller housing ring cannot be independently mounted on the pump body and cover, maintenance requires disassembling the pump rotor assembly, bearing housing, bearings, mechanical seals, bushings, and impeller. Reinstalling these parts on the main shaft after maintenance causes further rotor imbalance and repeated damage to parts, further increasing pump noise and vibration, and increasing maintenance time and costs.

[0006] The defects of multistage split-case pumps, such as high vibration, noise, and main shaft breakage, are also related to the concentricity of the pump rotor assembly with the pump body, pump cover, and other components. In existing technology, due to dimensional errors within tolerance zones during the machining of pump parts, the pump rotor assembly may sag during assembly, causing misalignment between the impeller and the pump body / cover, the impeller and the wear ring, and the main shaft, bearings, and mechanical seals. Furthermore, after long-term use, corrosion can occur on the bearing housing, pump body, and pump cover surfaces, leading to dimensional deviations in the fit between these components. This causes the pump rotor assembly to sag during operation. When the rotor assembly sags, it cannot be lifted as a whole to eliminate the misalignment between the rotor and other components, resulting in misalignment between the rotating parts and the non-rotating parts. Friction in rotating parts causes damage, leading to increased pump vibration and noise. This results in damage to the inducer impeller ring, impeller chamber ring, impeller ring, and hub ring. Furthermore, as the pump rotor sags, the impeller deviates from the center of the interstage impeller pressure chamber, interstage impeller suction chamber, and final stage secondary impeller pressure chamber. This causes an imbalance between the impeller and the flow channel, resulting in pressure fluctuations and vortices during hydraulic energy conversion. These fluctuations, vortexes, and interstage cavitation further damage the pump. Additionally, the pump's bearing housing is typically a single unit, only fitted to the pump body for positioning and not to the pump cover. When the pump is assembled, the bearing housing is a single unit, making it impossible to check the levelness and lateral position of the bearings and shaft on the pump rotor assembly relative to the pump body. This compromises the assembly accuracy of the pump rotor, leading to misalignment, friction damage, and increased pump vibration and noise. Furthermore, during maintenance after a period of operation, the bearing housing requires complete disassembly of the bearing housing and other components for inspection and repair, wasting time and manpower. Reassembly after disassembly can also introduce errors, potentially causing pump vibration. Increased risk: When the bearing housing is only positioned and fixed with the pump body but not with the pump cover, the bearing housing does not simultaneously form a circumferential ring fit with both the pump body and the pump cover. The bearing housing cannot form an integral part with the pump body and the pump cover, making it difficult to guarantee the assembly quality and accuracy of the rotor during assembly. Furthermore, the rigidity of the bearing housing and the pump body is also difficult to guarantee. At the same time, during pump operation, because the upper surface of the end of the bearing housing is radially suspended and does not fit with the pump cover, it cannot form end face support and force bearing. The bearing housing is prone to warping and loosening, and the pump rotor components are prone to "U"-shaped deformation, causing the impeller to deviate from the center of the pump's pressure chamber and suction chamber, which will also increase the pump's operating noise and vibration.

[0007] Furthermore, multi-stage split-case pumps, due to the stacking of multiple secondary positive impellers, experience very high pressure at the primary suction chamber of the secondary reverse impeller. In existing technology, the mechanical seal at the primary suction chamber end of the secondary reverse impeller does not provide pressure relief for the high-pressure liquid entering the mechanical seal chamber. Therefore, the mechanical seal must withstand high pressure, and the high-pressure fluctuations in the pump cavity directly impact and damage the mechanical seal. Simultaneously, to withstand these high-pressure fluctuations, high-load mechanical seals are typically selected, resulting in high selection and maintenance costs. Moreover, during the pump shaft's rotation, the rotating friction pair end face of the mechanical seal easily generates frictional heat, accelerating the aging of the sealing elements. Furthermore, impurities contained in the medium in the pump cavity directly enter the rotating friction pair end face of the mechanical seal, causing damage. This leads to high-pressure liquid leakage, causing environmental pollution and affecting operator safety, reducing the pump's operational stability, reliability, and safety, shortening the pump's operating and service life, and increasing the pump's operation, maintenance, and repair costs. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and provide a multi-stage split-case pump with a long service life. It can eliminate both the axial force generated by the impeller during operation and the radial force generated by the high and low pressure liquid in the impeller cavity on the impeller during operation, thereby eliminating the axial stress vibration and radial stress vibration of the rotor assembly, ensuring stable and reliable pump operation, and extending the pump's operation and service life.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0010] A multi-stage split-case pump with a long lifespan includes a pump body, a pump shaft, a drive-side bearing housing, a high-pressure-side bearing housing, and a pump base. The pump body consists of a pump casing and a pump cover. The pump shaft is rotatably mounted on the pump body, with its two ends extending from both ends of the pump body. The drive-side bearing housing is fixedly installed at the drive end of the pump body and connected to the pump shaft. The high-pressure-side bearing housing is fixedly installed at the high-pressure end of the pump body and connected to the pump shaft. From its drive end to its high-pressure end, the pump body sequentially comprises a drive-side mechanical seal chamber, a first-stage suction chamber, an inducer chamber for housing an inducer, a positive impeller chamber for housing a positive impeller, an impeller pressure relief chamber, and a pump base. The pump body comprises a reverse impeller chamber, a secondary suction chamber, a mechanical seal pressure relief chamber, and a high-pressure side mechanical seal chamber; the inlet of the pump body, the primary suction chamber, and the inducer chamber are sequentially connected; the positive impeller chamber includes a primary positive impeller chamber, several secondary positive impeller chambers, and a final positive impeller chamber sequentially connected; the primary reverse impeller chamber is connected to the secondary suction chamber, the upper end of the final positive impeller chamber is connected to the upper end of the secondary suction chamber through a pump cover transition channel, and the lower end of the final positive impeller chamber is connected to the lower end of the secondary suction chamber through a pump body transition channel; the pump cover transition channel and the pump body transition channel are arranged symmetrically about the pump shaft; the reverse impeller chamber includes... The pump comprises a first-stage reverse impeller chamber, several secondary reverse impeller chambers, and a final-stage reverse impeller chamber, connected sequentially. The first-stage reverse impeller chamber is connected to the secondary suction chamber, and the final-stage reverse impeller chamber is connected to the outlet of the pump body. The inducer, the forward impeller, and the reverse impeller are all fixedly mounted on the pump shaft. The number of forward impellers and the number of reverse impellers are equal and arranged symmetrically about the impeller pressure relief chamber. Flow channels are formed between adjacent forward impeller chambers and between adjacent reverse impeller chambers, and the radial cross-sectional shape of the flow channels is a standard circle. The impeller pressure relief chamber is connected to the last secondary forward impeller chamber through a first pressure relief pipe. The mechanical seal pressure relief chamber is connected to the first-stage positive impeller chamber via a second pressure relief pipe. The inducer chamber, the space between the inducer chamber and the positive impeller chamber, the space between two adjacent positive impeller chambers, the space between the last-stage positive impeller chamber and the impeller pressure relief chamber, the space between the impeller pressure relief chamber and the last-stage reverse impeller chamber, the space between two adjacent reverse impeller chambers, the space between the reverse impeller chamber and the secondary intake chamber, the space between the secondary intake chamber and the mechanical seal pressure relief chamber, and the space between the mechanical seal pressure relief chamber and the high-pressure side mechanical seal chamber are respectively provided with an inducer ring mounting position. The inducer chamber's corresponding ring mounting position is provided with an inducer ring that is clearance-fitted with the inducer.Hub rings, which mate with the clearance between the impeller hubs on both sides, are respectively provided at the following locations: the corresponding mounting position between the inducer chamber and the positive impeller chamber; the corresponding mounting position between two adjacent positive impeller chambers; the corresponding mounting position between the final stage positive impeller chamber and the impeller pressure relief chamber; the corresponding mounting position between the impeller pressure relief chamber and the final stage reverse impeller chamber; the corresponding mounting position between two adjacent reverse impeller chambers; and the corresponding mounting position between the reverse impeller chamber and the secondary suction chamber. A throttling ring, which mates with the clearance between the pump shaft, is provided at the corresponding mounting position between the secondary suction chamber and the mechanical seal pressure relief chamber. A flow-blocking ring, which mates with the clearance between the pump shaft, is provided at the corresponding mounting position between the mechanical seal pressure relief chamber and the high-pressure side mechanical seal chamber.

[0011] In a preferred embodiment of the present invention, a positive impeller pressure chamber, a positive impeller annular chamber, and a positive impeller suction chamber are sequentially connected between two adjacent positive impeller chambers. The positive impeller pressure chamber, the positive impeller annular chamber, and the positive impeller suction chamber constitute the flow channel. The positive impeller annular chamber surrounds the radially outer sides of the positive impeller pressure chamber and the positive impeller suction chamber. The positive impeller pressure chamber and the positive impeller suction chamber are separated by corresponding inlet ring mounting positions. The positive impeller pressure chamber surrounds the previous one... The positive impeller chamber is located on the outer periphery of the next positive impeller chamber and is in communication with it; the positive impeller suction chamber is located on the axial side of the next positive impeller chamber and is in communication with it; the radial outer side of the last-stage positive impeller chamber is surrounded by a positive impeller volute chamber, the upper end of which is in communication with the upper end of the secondary suction chamber through a pump cover transition channel, and the lower end of which is in communication with the lower end of the secondary suction chamber through a pump body transition channel; a series of interconnected reverse impeller volute chambers are formed between two adjacent reverse impeller chambers. The system comprises a water chamber, a reverse impeller annular chamber, and a reverse impeller suction chamber. These three chambers constitute the flow channel. The reverse impeller annular chamber surrounds the radially outer sides of both the reverse impeller pressure chamber and the reverse impeller suction chamber. The pressure chamber and suction chamber are separated by corresponding inlet ring mounting positions. The pressure chamber surrounds and communicates with the preceding reverse impeller chamber. The suction chamber is located on the axis of the next reverse impeller chamber. The impeller is directed to one side and communicates with the reverse impeller chamber; a reverse impeller volute chamber is provided radially outside the final stage reverse impeller chamber, and the reverse impeller volute chamber is communicated with the outlet of the pump body; multiple circumferentially distributed volute chamber guide vanes are formed in both the positive impeller volute chamber and the reverse impeller volute chamber; multiple circumferentially distributed suction chamber guide vanes are formed in both the positive impeller suction chamber and the reverse impeller suction chamber; multiple circumferentially distributed volute chamber guide vanes are formed in both the positive impeller volute chamber and the reverse impeller volute chamber.

[0012] As a preferred embodiment of the present invention, the inducer ring, hub ring, throttling ring, and flow-blocking ring are all composed of two half-rings, which are joined together to form a circular ring. The half-rings have symmetrical radial protrusions on both sides near their open ends. The upper surface of the radial protrusions is flush with the end face of the open end of the half-ring, and the lower surface of the radial protrusions is a horizontal positioning surface. The end face of the radial protrusions away from the half-ring is a radial positioning surface. The outer circumferential surface of the half-ring near the radial protrusions is an anti-rotation surface. The anti-rotation surfaces on both sides of the half-ring are parallel to each other. Each ring mounting position has a mounting base surface that respectively conforms to the horizontal positioning surface, the radial positioning surface, and the anti-rotation surface. The radial protrusions have countersunk holes penetrating their upper and lower surfaces. The mounting base surface conforming to the horizontal positioning surface has a threaded hole opposite to the countersunk hole, and a screw passes through the countersunk hole and connects to the threaded hole.

[0013] In a preferred embodiment of the present invention, a first-stage suction guide cone is formed in the first-stage suction chamber, through which the pump shaft can pass; the outer wall surface of the first-stage suction guide cone smoothly transitions with the inner wall surface of the first-stage suction chamber, and the outer diameter of the first-stage suction guide cone gradually decreases from the first-stage suction chamber to the inducer chamber; a second-stage suction guide cone is formed in the second-stage suction chamber, through which the rotor assembly can pass; the outer wall surface of the second-stage suction guide cone smoothly transitions with the inner wall surface of the second-stage suction chamber, and the outer diameter of the second-stage suction guide cone gradually decreases from the second-stage suction chamber to the first-stage impeller chamber.

[0014] As a preferred embodiment of the present invention, the drive-side mechanical seal chamber and the high-pressure side mechanical seal chamber are respectively connected to a heat exchanger. The heat exchanger is provided with a first heat exchange medium channel and a second heat exchange medium channel. The first heat exchange medium channel is connected to the cooling water pipeline system, and the second heat exchange medium channel is connected to the drive-side mechanical seal chamber or the high-pressure side mechanical seal chamber to form a circulation loop.

[0015] As a preferred embodiment of the present invention, the drive-side mechanical seal chamber is surrounded radially on the outer side by a drive-side mechanical seal cooling chamber that is adjacent to it but not connected thereto, and the drive-side mechanical seal cooling chamber is connected to the cooling water pipeline system; the high-pressure side mechanical seal chamber is surrounded radially on the outer side by a high-pressure side mechanical seal cooling chamber that is adjacent to it but not connected thereto, and the high-pressure side mechanical seal cooling chamber is connected to the cooling water pipeline system.

[0016] In a preferred embodiment of the present invention, the drive-side bearing housing includes a first housing body and a first housing cover, the first housing cover being disposed above the first housing body; the first housing cover and the first housing body together form a first outer shaft seal mounting position, a first sliding bearing lubricating oil chamber, a first sliding bearing mounting position, a first return oil chamber, a first inner shaft seal mounting position, and a first open chamber arranged sequentially from the outside to the inside along the pump shaft direction; a first outer shaft seal assembly is mounted on the first outer shaft seal mounting position, a first sliding bearing assembly is mounted on the first sliding bearing mounting position, and a first inner shaft seal assembly is mounted on the first inner shaft seal mounting position. The side shaft seal assembly includes a first sliding bearing lubricating oil chamber and a first return oil chamber connected by a first return oil channel; the side wall of the first open chamber has a first opening communicating with the outside atmosphere; the bottom of the first sliding bearing lubricating oil chamber is provided with a first corrugated heat exchange plate, and a first cooling cover is provided on the first corrugated heat exchange plate, forming a first lubricating oil cooling chamber between the first cooling cover and the first corrugated heat exchange plate, which is connected to a cooling water pipeline system; the high-pressure side bearing housing includes a second housing body and a second housing cover, with the second housing cover covering the second housing body. The second cover and the second housing together form an outer cover mounting position, a rolling bearing lubricating oil chamber, a rolling bearing mounting position, a second sliding bearing lubricating oil chamber, a second sliding bearing mounting position, a second return oil chamber, a second inner shaft seal mounting position, and a second open chamber arranged sequentially from the outside to the inside along the pump shaft direction. A sealing cover is installed on the outer cover mounting position. A rolling bearing assembly is installed on the rolling bearing mounting position. A second sliding bearing assembly is installed on the second sliding bearing mounting position. A second inner shaft seal assembly is installed on the second inner shaft seal mounting position. The second sliding bearing lubricating oil chamber and the second... The two oil return chambers are connected by a second oil return channel, and the second sliding bearing lubricating oil chamber and the rolling bearing lubricating oil chamber are connected by a third oil return channel; the side wall of the second open chamber is provided with a second opening that communicates with the outside atmosphere; the bottom of the second sliding bearing lubricating oil chamber is provided with a second corrugated heat exchange plate, and a second cooling cover is provided on the second corrugated heat exchange plate, and the second cooling cover and the second corrugated heat exchange plate enclose a second lubricating oil cooling chamber, which is connected to the cooling water pipeline system; the top of both the first oil return chamber and the second oil return chamber is provided with an exhaust hood.

[0017] In a preferred embodiment of the present invention, the first sliding bearing assembly includes a first bearing housing and a first sliding bearing. The first bearing housing is fixed to the first sliding bearing mounting position by screws, and the first sliding bearing is mounted on the first bearing housing. A first oil slinger ring and a first baffle are provided in the lubrication oil chamber of the first sliding bearing. The first oil slinger ring is sleeved on the pump shaft and rotates friably with the pump shaft. The first oil slinger ring is close to the first sliding bearing, and the first baffle is fixed to the first bearing housing by screws and blocks the first oil slinger ring from the side away from the first sliding bearing. The second sliding bearing assembly includes a second bearing housing and a second sliding bearing. The second bearing housing is fixed to the second sliding bearing mounting position by screws, and the second sliding bearing is mounted on the second bearing housing. A second oil slinger ring and a second baffle are provided in the lubrication oil chamber of the second sliding bearing. The second oil slinger ring is sleeved on the pump shaft and rotates friably with the pump shaft. The second oil slinger ring is close to the first sliding bearing. The second sliding bearing has a second baffle fixed to the second bearing housing by screws and blocking the second oil slinger ring away from the second sliding bearing. The rolling bearing assembly includes a rolling bearing and a clamping member. The rolling bearing mounting position forms a limiting convex ring on the side near the lubricating oil chamber of the second sliding bearing. The clamping member is fixed to the side of the rolling bearing mounting position away from the lubricating oil chamber of the second sliding bearing by screws. The outer ring of the rolling bearing is pressed between the limiting convex ring and the clamping member. Two rolling bearings are stacked along the pump shaft direction. The lubricating oil chamber of the rolling bearing is provided with a third oil slinger ring, an oil ring seat, and a clamping nut. The oil ring seat is sleeved on the pump shaft. The clamping nut is threaded to the end of the pump shaft and presses the oil ring seat and the inner ring of the rolling bearing onto the pump shaft shoulder. The third oil slinger ring is sleeved on the oil ring seat and rotates rubbing against the oil ring seat. The outer circumference of the oil ring seat is provided with a limiting groove that cooperates with the third oil slinger ring.

[0018] As a preferred embodiment of the present invention, both the first outer shaft seal assembly and the first inner shaft seal assembly include a first oil baffle ring, a first oil blocking ring, and a first dust cover sleeved on the pump shaft. The first oil baffle ring is fixed to the first outer shaft seal mounting position or the first inner shaft seal mounting position by screws. The first oil baffle ring has a first receiving groove on the side away from the first sliding bearing lubricating oil chamber or the first return oil chamber, into which the first oil blocking ring can be embedded. The first dust cover is disposed on the first receiving groove and fastened to the pump shaft by screws. The second inner shaft seal assembly includes a second oil baffle ring, a second oil blocking ring, and a second dust cover sleeved on the pump shaft. The second oil baffle ring is fixed to the second inner shaft seal mounting position by screws. The second oil baffle ring has a second receiving groove on the side away from the second sliding bearing lubricating oil chamber, into which the second oil blocking ring can be embedded. The second dust cover is disposed on the second receiving groove and fastened to the pump shaft by screws.

[0019] As a preferred embodiment of the present invention, the first housing and the second housing are respectively provided with axially protruding first stop semi-rings on their end faces facing the pump body; the first housing cover and the second housing cover are respectively provided with axially protruding second stop semi-rings on their end faces facing the pump cover; the first stop semi-rings and the second stop semi-rings cooperate to form a stop ring; a lifting mechanism that cooperates with the first stop semi-ring is respectively installed on the end faces of the two ends of the pump body; the end faces of the two ends of the pump cover are provided with semi-ring stopes that cooperate with the second stop semi-ring; the lifting mechanism includes a lifting cone ring and an adjusting screw, the lifting cone ring is provided with a semi-ring connecting part and a semi-ring stop part, the semi-ring stop part is formed on the upper end of the semi-ring connecting part, and the semi-ring stop part is formed on the upper end of the semi-ring connecting part. The bottom of the first stop half-ring abuts against each other; the stop portion of the half-ring has a half-ring protrusion facing the pump body, and the outer peripheral surface of the half-ring protrusion is a first conical surface; the end face of the pump body has a half-ring recess for mounting the lifting cone ring, and the lower side of the half-ring recess is a second conical surface that slides with the first conical surface; the half-ring connecting part has multiple mounting holes evenly distributed, and the end face of the pump body has threaded holes corresponding to the mounting holes one by one. The adjusting screw passes through the mounting hole and connects to the threaded hole; when the adjusting screw is screwed in or out of the threaded hole, it can drive the lifting cone ring to raise or lower the pump bearing housing, change the relative position of the pump bearing housing and the pump body, and thus adjust the height position of the pump shaft.

[0020] As a preferred embodiment of the present invention, the drive-side bearing housing is provided with a first X-axis vibration probe interface, a first Y-axis vibration probe interface, a first Z-axis vibration probe interface, and a first temperature probe interface; a first X-axis vibration probe for detecting X-axis vibration of the drive-side bearing housing is installed on the first X-axis vibration probe interface; a first Y-axis vibration probe for detecting Y-axis vibration of the drive-side bearing housing is installed on the first Y-axis vibration probe interface; a first Z-axis vibration probe for detecting Z-axis vibration of the drive-side bearing housing is installed on the first Z-axis vibration probe interface; and a first temperature probe for detecting the oil temperature in the first return oil chamber is installed on the first temperature probe interface. A temperature probe is provided; the high-pressure side bearing housing is provided with a second X-axis vibration probe interface, a second Y-axis vibration probe interface, a second Z-axis vibration probe interface, and a second temperature probe interface; a second X-axis vibration probe for detecting the X-axis vibration of the drive-side bearing housing is installed on the second X-axis vibration probe interface; a second Y-axis vibration probe for detecting the Y-axis vibration of the drive-side bearing housing is installed on the second Y-axis vibration probe interface; a second Z-axis vibration probe for detecting the Z-axis vibration of the drive-side bearing housing is installed on the second Z-axis vibration probe interface; and a second temperature probe for detecting the oil temperature in the second return oil chamber is installed on the second temperature probe interface.

[0021] As a preferred embodiment of the present invention, the pump body is provided with shaft seal covers at both ends, and the shaft seal covers are respectively provided at the outer port of the drive-side mechanical seal chamber and the outer port of the high-pressure side mechanical seal chamber. At least two O-rings are provided between the shaft seal covers and the pump body. Both the drive-side mechanical seal chamber and the high-pressure side mechanical seal chamber are provided with mechanical seals sleeved on the pump shaft. The mechanical seals can form a sealed connection structure between the pump shaft and the shaft seal covers.

[0022] As a preferred embodiment of the present invention, a throttling sleeve and a flow-blocking sleeve are fixedly sleeved at positions corresponding to the throttling ring, the mechanical seal pressure relief chamber, the flow-blocking ring, the high-pressure side mechanical seal chamber, the mechanical seal, and the shaft seal cover. The throttling ring is sleeved on the throttling sleeve and forms a spiral throttling channel between the throttling sleeve and the throttling sleeve. The flow-blocking ring is sleeved on the flow-blocking sleeve and forms a spiral flow-blocking channel between the flow-blocking sleeve and the flow-blocking sleeve.

[0023] As a preferred embodiment of the present invention, a clamping sleeve, a water-blocking nut, and a locking nut are further fitted onto the end of the pump shaft away from the flow-blocking sleeve. The water-blocking nut and the locking nut are threadedly connected to the pump shaft. When the water-blocking nut and the locking nut are both screwed toward the clamping sleeve, the water-blocking nut presses the clamping sleeve, the flow-blocking sleeve, and the flow-blocking sleeve onto the shoulder of the pump shaft in sequence, and the locking nut presses onto the water-blocking nut. The flow-blocking sleeve passes through the shaft seal cover, and an O-ring is clamped at the joint between the flow-blocking sleeve and the clamping sleeve. The inner ring of the O-ring tightly abuts against the outer circumferential surface of the pump shaft.

[0024] As a preferred embodiment of the present invention, the pump base is provided with a support foot for fixing and supporting the pump body, and the support foot is provided with a support foot cooling chamber, which is connected to the cooling water pipeline system.

[0025] The multi-stage split-case pump with a long lifespan provided by this invention has the following advantages compared with the prior art:

[0026] (1) The present invention adopts a back-to-back double-suction symmetrical structure formed by multiple positive impellers and multiple negative impellers, so that the axial forces generated by the impellers in the rotor components of the pump cancel each other out during operation; at the same time, by setting an impeller pressure relief chamber between the final stage positive impeller chamber and the final stage negative impeller chamber, and the impeller pressure relief chamber is connected to the last secondary positive impeller chamber through the first pressure relief pipe, when the high-pressure liquid in the final stage negative impeller chamber enters the impeller pressure relief chamber through the impeller hub fitting clearance, the high-pressure liquid in the final stage negative impeller chamber flows into the positive impeller annular chamber corresponding to the last secondary positive impeller chamber through the pressure relief pipe for pressure relief, and then flows into the secondary positive impeller. In the pump chamber, the liquid is pressurized again by the secondary positive impeller. After the high-pressure liquid in the impeller pressure relief chamber is released, the liquid pressure in the impeller pressure relief chamber is completely balanced with the liquid pressure in the final stage positive impeller chamber. Therefore, the rear cover plate of the final stage positive impeller is not subjected to liquid pressure and does not generate axial force. This eliminates axial force on the pump rotor components during operation, thereby preventing the bearings from bearing the axial force of the pump and the pump shaft from bearing axial tensile and compressive stress. This eliminates axial stress vibration of the rotor components, prevents the generation of medium vortices, improves hydraulic efficiency, prevents cavitation, ensures stable and reliable pump operation, and extends the pump's operation and service life.

[0027] (2) The present invention uses a pump cover transition channel and a pump body transition channel arranged symmetrically on the upper and lower sides, and forms a flow channel with a standard circular radial cross-section between two adjacent positive impeller chambers and between two adjacent positive impeller chambers. This makes the radial hydraulic impact in the pump body cancel each other out, so as to achieve radial balance. Therefore, the impeller is not affected by the high and low pressure liquid in the impeller chamber during operation and does not generate radial force. This eliminates the radial force in the pump rotor component during operation, thereby preventing the pump shaft from bearing bending stress and alternating shear stress, eliminating the radial stress vibration of the rotor component, ensuring stable and reliable pump operation, and extending the operation and service life of the pump. In addition, the flow channel with a standard circular radial cross-section is simple in structure and has a small volume space compared with the spiral volute flow channel, which is conducive to shortening the axial dimension of the pump body. It can also use a modular form of axial superposition and extension to complete the flow channel design, which is conducive to increasing or decreasing the number of impeller stages. The mold structure is simple and the cost is low. In addition, the pump cover transition channel is formed in the pump cover and the pump body transition channel is formed in the pump body, which is compact and has high strength.

[0028] (3) The present invention sets up a mechanical seal pressure relief chamber between the secondary suction chamber and the high-pressure side mechanical seal chamber, and the mechanical seal pressure relief chamber is connected to the first stage positive impeller chamber through the second pressure relief pipe. When the high pressure liquid in the secondary suction chamber undergoes the first flow restriction and pressure reduction through the gap channel formed between the throttle ring and the pump shaft, it enters the mechanical seal pressure relief chamber. The pressurized liquid in the mechanical seal pressure relief chamber flows into the first stage positive impeller chamber through the second pressure relief pipe for pressure relief, and is pressurized again by the first stage positive impeller. At this time, the pressurized liquid in the mechanical seal pressure relief chamber is completely balanced with the liquid pressure in the first stage positive impeller chamber after pressure relief. The pressurized liquid in the mechanical seal pressure relief chamber undergoes the second flow restriction and pressure reduction through the gap channel formed between the throttle ring and the pump shaft. Finally, the high-pressure side mechanical seal chamber receives a very low pressure liquid, which effectively prevents the high pressure liquid from impacting the mechanical seal in the high-pressure side mechanical seal chamber. At the same time, it can effectively isolate impurities in the pressurized liquid from entering the high-pressure side mechanical seal chamber and damaging the mechanical seal, thereby ensuring the sealing performance of the high-pressure side of the pump body and effectively preventing the pump conveying medium from leaking along the pump shaft. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below.

[0030] Figure 1 This is a schematic diagram of the structure of a multi-stage split-case pump with a long lifespan provided in an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the pump body.

[0032] Figure 3 It is at Figure 2 The structural schematic diagram shown is a view of the pump body from the downward section AA.

[0033] Figure 4 It is at Figure 2 A schematic diagram of the structure shown, with the BB section viewed from below.

[0034] Figure 5 This is a magnified view of a portion of the high-pressure end of the pump body;

[0035] Figure 6 This is a structural schematic diagram of the drive-side bearing housing;

[0036] Figure 7 This is a cross-sectional view of the drive-side bearing housing when the housing and cover are fitted together.

[0037] Figure 8 This is a side view of the drive-side bearing housing when the housing and cover are fitted together.

[0038] Figure 9 This is a structural schematic diagram of the high-pressure side bearing housing;

[0039] Figure 10 This is a structural diagram showing the fit between the housing and the cover of the high-pressure side bearing housing.

[0040] Figure 11 This is a side view of the high-pressure side bearing housing when the housing and cover are fitted together.

[0041] Figure 12 This is a schematic diagram of the lifting mechanism;

[0042] Figure 13 This is the front view of the lifting cone ring;

[0043] Figure 14 This is a cross-sectional view of the lifting cone ring;

[0044] Figure 15 This is a schematic diagram of the oral ring structure;

[0045] Figure 16 This is a schematic diagram of the mouth ring mounting position.

[0046] Marked in the image:

[0047] Pump body 100; Pump body inlet 100a; Pump body outlet 100b; Pump body 101; Pump cover 102; Drive-side mechanical seal chamber 103; First-stage suction chamber 104; Inducer chamber 105; Positive impeller chamber 106; First-stage positive impeller chamber 106a; Second-stage positive impeller chamber 106b; Final-stage positive impeller chamber 106c; Impeller pressure relief chamber 107; Reverse impeller chamber 108; First-stage reverse impeller chamber 108a; Second-stage reverse impeller chamber 108b; Final-stage reverse impeller chamber 108c; Secondary suction chamber 109; Mechanical seal pressure relief chamber 110; High-pressure side mechanical seal chamber 111; Flow passage 112; First pressure relief pipe 113; Second pressure relief pipe 114; Inlet ring mounting position 115; Inducer impeller inlet ring 116; Hub inlet ring 117; Throttling inlet ring 118; Flow obstruction inlet ring 119; Positive impeller water pressure chamber 120; Positive impeller annular chamber 121; Positive impeller suction chamber 122; Positive impeller water pressure volute chamber 123; Pump cover transition passage 124; Pump body transition channel 125; impeller water chamber 126; impeller annular chamber 127; impeller suction chamber 128; impeller water volute chamber 129; water chamber guide vane 130; suction chamber guide vane 131; water volute chamber guide vane 132; half-hole ring 133; radial convex edge 134; horizontal positioning surface 135; radial positioning surface 136; anti-rotation vertical surface 137; first mounting base 138; second mounting base 139; third mounting base 140; countersunk hole 14 1; Threaded hole 142; First-stage suction guide cone 143; Inducer wheel suction chamber 144; Spiral flow obstruction channel 145; Secondary suction guide cone 146; Drive-side mechanical seal cooling chamber 147; High-pressure side mechanical seal cooling chamber 148; Semi-ring stop 149; Semi-ring recess 150; Second conical surface 151; Threaded hole 152; Shaft seal cover 153; Mechanical seal 154; Throttling channel 155; Flow obstruction channel 156; O-ring seal 157; Bolt 158;

[0048] Pump shaft 200; inducer 201; positive impeller 202; negative impeller 203; throttling shaft sleeve 205; flow-blocking shaft sleeve 206; clamping shaft sleeve 206; water-blocking nut 207; lock nut 208; O-ring seal 209;

[0049] Drive-side bearing housing 300; First housing 301; First housing cover 302; First outer shaft seal mounting position 303; First sliding bearing lubrication oil chamber 304; First sliding bearing mounting position 305; First oil return chamber 306; First inner shaft seal mounting position 307; First open chamber 308; First outer shaft seal assembly 309; First sliding bearing assembly 310; First inner shaft seal assembly 311; First oil return channel 312; First opening 313; First corrugated heat exchange plate 314; First cooling cover 315; First lubrication... Oil cooling chamber 316; First bearing housing 317; First sliding bearing 318; First oil slinger ring 319; First baffle 320; First oil baffle ring 321; First oil blocking ring 322; First dust cover 323; First X-axis vibration probe interface 324; First Y-axis vibration probe interface 325; First Z-axis vibration probe interface 326; First temperature probe interface 327; First stop half ring 328; Second stop half ring 329; Reinforcing rib 330; Exhaust hood 331;

[0050] High-pressure side bearing housing 400; second housing 401; second housing cover 402; outer cover mounting position 403; rolling bearing lubricating oil chamber 404; rolling bearing mounting position 405; second sliding bearing lubricating oil chamber 406; second sliding bearing mounting position 407; second oil return chamber 408; second inner shaft seal mounting position 409; second open chamber 410; sealing cover 411; rolling bearing assembly 412; second sliding bearing assembly 413; second inner shaft seal assembly 414; second oil return channel 415; third oil return channel 416; second open opening 417; second corrugated heat exchange plate 418; second cold... Cover 419; Second lubricating oil cooling chamber 420; Second bearing seat 421; Second sliding bearing 422; Second oil slinger ring 423; Second baffle 424; Rolling bearing 425; Clamping part 426; Limiting protrusion ring 427; Third oil slinger ring 428; Oil ring seat 429; Clamping nut 430; Limiting groove 431; Second oil baffle ring 432; Second oil blocking ring 433; Second dust cover 434; Second X-axis vibration probe interface 435; Second Y-axis vibration probe interface 436; Second Z-axis vibration probe interface 437; Second temperature probe interface 438; Reinforcing rib 439; Exhaust hood 440;

[0051] Pump base 500; support foot 501;

[0052] Heat exchanger 600;

[0053] Cooling water piping system 700;

[0054] Lifting mechanism 800; lifting cone ring 801; adjusting screw 802; semi-ring connecting part 803; semi-ring stop part 804; semi-ring protrusion 805; first conical surface 806; mounting hole 807; bolt clearance groove 808. Detailed Implementation

[0055] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0056] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this 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 limiting this invention.

[0057] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. Any mention of "first" is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0058] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0059] Please refer to the following: Figures 1 to 16 The multi-stage split-case pump with a long lifespan provided in the embodiments of the present invention will now be described.

[0060] like Figures 1 to 3 , Figure 5As shown in the preferred embodiment of the present invention, a multi-stage split-case pump with a long lifespan includes a pump body 100, a pump shaft 200, a drive-side bearing housing 300, a high-pressure-side bearing housing 400, and a pump base 500. The pump body 100 is composed of a pump body 101 and a pump cover 102. The pump shaft 200 is rotatably mounted on the pump body 100, with its two ends extending from both ends of the pump body 100. The drive-side bearing housing 300 is fixedly installed at the drive end of the pump body 100 and connected to the pump shaft 200. The high-pressure-side bearing housing 400 is fixedly installed at the high-pressure end of the pump body 100 and connected to the pump shaft 200. The pump body 100 extends from its drive end to its high-pressure end... The pump body 100 is arranged with a drive-side mechanical seal chamber 103, a primary suction chamber 104, an inducer chamber 105 for housing an inducer wheel 201, a positive impeller chamber 106 for housing a positive impeller 202, an impeller pressure relief chamber 107, a negative impeller chamber 108 for housing a negative impeller 203, a secondary suction chamber 109, a mechanical seal pressure relief chamber 110, and a high-pressure side mechanical seal chamber 111. The pump body 100 inlet 100a, the primary suction chamber 104, and the inducer chamber 105 are sequentially connected. The positive impeller chamber 106 includes a primary positive impeller chamber 106a, several secondary positive impeller chambers 106b, and a final positive impeller chamber 106c, all sequentially connected. The primary negative impeller chamber 108 is connected to the secondary suction chamber 109. The upper end of the final stage positive impeller chamber 106c is connected to the upper end of the secondary suction chamber 109 through the pump cover transition channel 124, and the lower end of the final stage positive impeller chamber 106c is connected to the lower end of the secondary suction chamber 109 through the pump body transition channel 125. The pump cover transition channel 124 and the pump body transition channel 125 are arranged symmetrically about the pump shaft 200. The reverse impeller chamber 108 includes a first stage reverse impeller chamber 108a, several secondary reverse impeller chambers 108b, and a final stage reverse impeller chamber 108c connected in sequence. The first stage reverse impeller chamber 108a is connected to the secondary suction chamber 109, and the final stage reverse impeller chamber 108c is connected to the outlet 100b of the pump body 100. The pump shaft 200 is fixedly mounted on the inducer 201, the positive impeller 202, and the negative impeller 203. The number of positive impellers 202 and the number of negative impellers 203 are equal and arranged symmetrically about the impeller pressure relief chamber 107. A flow passage 112 is formed between two adjacent positive impeller chambers 106 and between two adjacent negative impeller chambers 108. The radial cross-sectional shape of the flow passage 112 is a standard circle. The impeller pressure relief chamber 107 is connected to the last secondary positive impeller chamber 106b through a first pressure relief pipe 113. The mechanical seal pressure relief chamber 110 is connected to the first-stage positive impeller chamber 106a through a second pressure relief pipe 114.A mouth ring mounting position 115 is provided in the inducer chamber 105, between the inducer chamber 105 and the positive impeller chamber 106, between two adjacent positive impeller chambers 106, between the final stage positive impeller chamber 106c and the impeller pressure relief chamber 107, between the impeller pressure relief chamber 107 and the final stage reverse impeller chamber 108c, between two adjacent reverse impeller chambers 108, between the reverse impeller chamber 108 and the secondary suction chamber 109, between the secondary suction chamber 109 and the mechanical seal pressure relief chamber 110, and between the mechanical seal pressure relief chamber 110 and the high-pressure side mechanical seal chamber 111. A mouth ring mounting position 115 is provided on the mouth ring mounting position 115 corresponding to the inducer chamber 105, which is clearance-fitted with the inducer 201. A mouth ring 116 is provided on the mouth ring mounting position 115 corresponding to the inducer chamber 105 and the positive impeller chamber 106, and on the mouth ring mounting position 115 corresponding to the positive impeller chamber 106, between two adjacent positive impeller chambers... Hub rings 117, which are clearance fits between the impeller hubs on both sides, are respectively provided on the following mounting positions: the corresponding mounting positions 115 between the final stage positive impeller chamber 106c and the impeller pressure relief chamber 107, the corresponding mounting positions 115 between the impeller pressure relief chamber 107 and the final stage reverse impeller chamber 108c, the corresponding mounting positions 115 between two adjacent reverse impeller chambers 108, and the corresponding mounting positions 115 between the reverse impeller chamber 108 and the secondary suction chamber 109; the corresponding mounting position 115 between the secondary suction chamber 109 and the mechanical seal pressure relief chamber 110 is provided with a throttling ring 118 that is clearance fits between the pump shaft 200; the corresponding mounting position 115 between the mechanical seal pressure relief chamber 110 and the high-pressure side mechanical seal chamber 111 is provided with a flow-blocking ring 119 that is clearance fits between the pump shaft 200.

[0061] Therefore, the key technology of the long-life multi-stage split-case pump provided by the embodiments of the present invention lies in:

[0062] First, the present invention employs a back-to-back double-suction symmetrical structure formed by multiple positive impellers 202 and multiple negative impellers 203, which allows the axial forces generated by the impellers in the pump rotor components to cancel each other out during operation. Simultaneously, by providing an impeller pressure relief chamber 107 between the final-stage positive impeller chamber 106c and the final-stage negative impeller chamber 108c, and connecting the impeller pressure relief chamber 107 to the last secondary positive impeller chamber 106b via a first pressure relief pipe 113, when the high-pressure liquid in the final-stage negative impeller chamber 108c enters the impeller pressure relief chamber 107 through the impeller hub clearance, the high-pressure liquid in the final-stage negative impeller chamber 108c flows through the pressure relief pipe into the annular chamber of the positive impeller 202 corresponding to the last secondary positive impeller chamber 106b for relief. The high-pressure liquid in the impeller pressure relief chamber 107 is released and flows into the secondary positive impeller chamber 106b. After being pressurized again by the secondary positive impeller 202, the high-pressure liquid in the impeller pressure relief chamber 107 is completely balanced with the liquid pressure in the final positive impeller chamber 106c. Therefore, the rear cover plate of the final positive impeller 202 is not subjected to liquid pressure and does not generate axial force. This eliminates axial force on the pump rotor components during operation, thereby preventing the bearings from bearing the axial force of the pump and the pump shaft 200 from bearing axial tensile and compressive stress. This eliminates axial stress vibration of the rotor components, prevents the generation of medium vortices, improves hydraulic efficiency, prevents cavitation, ensures stable and reliable pump operation, and extends the operation and service life of the pump.

[0063] Secondly, the present invention utilizes symmetrically arranged pump cover transition channels 124 and pump body transition channels 125, and forms flow channels 112 with a standard circular radial cross-section between adjacent impeller chambers 106 and between adjacent impeller chambers 106. This allows the radial hydraulic impacts within the pump body 100 to cancel each other out, achieving radial balance. Therefore, the impeller is not affected by the high and low pressure liquids in the impeller chamber during operation, thus preventing the generation of radial forces. This eliminates radial forces on the pump rotor components during operation, thereby preventing the pump shaft 200 from bearing bending stress and alternating shear stress, eliminating... Radial stress vibration of the rotor components ensures stable and reliable pump operation, extending the pump's operation and service life. Furthermore, the standard circular radial cross-section of the flow channel 112, compared to the spiral volute flow channel, has a simpler structure and smaller volume, which helps to shorten the axial dimension of the pump body 100. It also allows for the use of a modular form with axial stacking extension to complete the flow channel design, which is beneficial for increasing or decreasing the number of impeller stages. The mold structure is simple and the cost is low. In addition, the pump cover transition channel 124 is formed inside the pump cover 102, and the pump body transition channel 125 is formed inside the pump body 101, resulting in a compact structure and high strength.

[0064] Third, this invention provides a mechanical seal pressure relief chamber 110 between the secondary suction chamber 109 and the high-pressure side mechanical seal chamber 111, and the mechanical seal pressure relief chamber 110 is connected to the first-stage positive impeller chamber 106a via a second pressure relief pipe 114. When the high-pressure liquid in the secondary suction chamber 109 undergoes a first flow restriction and pressure reduction through the gap channel formed between the throttle ring 118 and the pump shaft 200, it enters the mechanical seal pressure relief chamber 110. The pressurized liquid in the mechanical seal pressure relief chamber 110 flows into the first-stage positive impeller chamber 106a through the second pressure relief pipe 114 for pressure relief, and is then pressurized again by the first-stage positive impeller 202. At this time, the pressurized liquid in the mechanical seal pressure relief chamber 110 flows through the second pressure relief pipe 114 into the first-stage positive impeller chamber 106a for pressure relief, and is then pressurized again by the first-stage positive impeller 202. After depressurization, the liquid pressure in the mechanical seal depressurization chamber 110 reaches complete equilibrium with the liquid pressure in the first-stage positive impeller chamber 106a. The pressurized liquid in the mechanical seal depressurization chamber 110 undergoes a second flow restriction and pressure reduction through the gap channel formed between the flow-blocking ring 119 and the pump shaft 200. Finally, the high-pressure side mechanical seal chamber 111 receives a very low pressure liquid, effectively preventing the high-pressure liquid from impacting the mechanical seal in the high-pressure side mechanical seal chamber 111. At the same time, it can effectively isolate impurities in the pressurized liquid from entering the high-pressure side mechanical seal chamber 111 and damaging the mechanical seal, thereby ensuring the sealing performance of the high-pressure side of the pump body 100 and effectively preventing the pumped medium from leaking along the pump shaft 200.

[0065] For example, such as Figures 1 to 4As shown, a positive impeller pressure chamber 120, a positive impeller annular chamber 121, and a positive impeller suction chamber 122 are sequentially connected between two adjacent positive impeller chambers 106. The positive impeller pressure chamber 120, the positive impeller annular chamber 121, and the positive impeller suction chamber 122 constitute the flow channel 112. The positive impeller annular chamber 121 surrounds the radial outer side of the positive impeller pressure chamber 120 and the radial outer side of the positive impeller suction chamber 122. The positive impeller pressure chamber 120 and the positive impeller suction chamber 122 are connected by corresponding annular openings. The impeller pressure chamber 120 is positioned 115 apart from the previous impeller chamber 106 and is connected to it. The impeller suction chamber 122 is located on the axial side of the next impeller chamber 106 and is connected to it. The radial outer side of the final stage impeller chamber 106c is surrounded by an impeller pressure volute 123. The upper end of the impeller pressure volute 123 is connected to the upper end of the secondary suction chamber 109 through the pump cover transition channel 124. The lower end of the impeller pressure volute 123... The end is connected to the lower end of the secondary suction chamber 109 through the pump body transition channel 125; between two adjacent impeller chambers 108, a reverse impeller pressure chamber 126, a reverse impeller annular chamber 127, and a reverse impeller suction chamber 128 are formed in sequence. The reverse impeller pressure chamber 126, the reverse impeller annular chamber 127, and the reverse impeller suction chamber 128 constitute the flow channel 112. The reverse impeller annular chamber 127 surrounds the radial outer side of the reverse impeller pressure chamber 126 and the radial outer side of the reverse impeller suction chamber 128. The impeller pressure chamber 126 and the reverse impeller suction chamber 128 are separated by corresponding inlet ring mounting positions 115. The reverse impeller pressure chamber 126 surrounds the outer periphery of the previous reverse impeller chamber 108 and communicates with the reverse impeller chamber 108. The reverse impeller suction chamber 128 is located on one axial side of the next reverse impeller chamber 108 and communicates with the reverse impeller chamber 108. The radial outer side of the final stage reverse impeller chamber 108c is surrounded by a reverse impeller pressure volute chamber 129, which communicates with the outlet 100b of the pump body 100. Furthermore, multiple circumferentially distributed pressure chamber guide vanes 130 are formed in both the positive impeller pressure chamber 120 and the negative impeller pressure chamber 126; multiple circumferentially distributed suction chamber guide vanes 131 are formed in both the positive impeller suction chamber 122 and the negative impeller suction chamber 128; and multiple circumferentially distributed pressure volute guide vanes 132 are formed in both the positive impeller pressure volute chamber 123 and the negative impeller pressure volute chamber 129. Thus, the suction chamber guide vanes 131, pressure chamber guide vanes 130, and pressure volute guide vanes 132 further ensure a circumferentially uniform distribution of their respective suction chambers, pressure chambers, and pressure volute chambers, improving the pressure balance around the impeller circumference and preventing radial forces from being transmitted to the rotor components from the blades and outer circumference of each impeller, thereby further eliminating radial forces during pump operation.

[0066] For example, such as Figure 1 , Figure 5 , Figure 15 and Figure 16 As shown, the inducer ring 116, hub ring 117, throttle ring 118, and choke ring 119 are each composed of two half-rings 133, which are joined together to form a circular ring. Each half-ring 133 has symmetrical radial protrusions 134 on both sides near its open end. The upper surface of the radial protrusions 134 is flush with the end face of the open end of the half-ring 133, and the lower surface of the radial protrusions 134 is a horizontal positioning surface 135. The end face of the radial protrusions 134 away from the half-ring 133 is a radial positioning surface 136. The outer circumferential surface of the half-ring 133 near the radial protrusions 134... The anti-rotation facet 137 is located on both sides of the half-ring 133 and is parallel to each other. Each of the ring mounting positions 115 is provided with a first mounting base surface 138, a second mounting base surface 139 and a third mounting base surface 140 that respectively fit with the horizontal positioning surface 135, the radial positioning surface 136 and the anti-rotation facet 137. The radial protrusion 134 is provided with a countersunk hole 141 that penetrates its upper and lower surfaces. The first mounting base surface 138 that fits with the horizontal positioning surface 135 is provided with a threaded hole 142 that is opposite to the countersunk hole 141. The screw passes through the countersunk hole 141 and connects to the threaded hole 142. Therefore, the inducer ring 116, hub ring 117, throttling ring 118, and flow-blocking ring 119 all adopt a split structure, with the two half-rings 133 respectively installed on the pump body 101 and pump cover 102. After the pump body 101 and pump cover 102 are installed together, the two half-rings 133 form a circular ring that mates with the rotor components. By designing the horizontal positioning surface 135, radial positioning surface 136, and anti-rotation vertical surface 137, rapid positioning of the half-rings 133 in the height, horizontal, and circumferential directions is achieved, ensuring the safety of the half-rings 133. The positioning of the two half-rings 133 prevents rotation of the half-ring, thus ensuring the concentricity of the circular ring and the rotor assembly. Since the two half-rings 133 can be directly mounted on the rotor assembly when the pump body 101 and pump cover 102 are installed together, the rings can be replaced independently during maintenance without disassembling the rotor assembly. This makes disassembly and assembly convenient, increases work efficiency, and effectively solves the problems of assembly imbalance and multiple damages to parts affecting assembly accuracy. It achieves independent dynamic balancing of the rotor assembly, ensuring stable and reliable pump operation and reducing pump maintenance time and costs.

[0067] For example, such as Figure 1 and Figure 2As shown, a first-stage suction guide cone 143 is formed in the first-stage suction chamber 104, through which the pump shaft 200 passes; the outer wall surface of the first-stage suction guide cone 143 smoothly transitions with the inner wall surface of the first-stage suction chamber 104, and the outer diameter of the first-stage suction guide cone 143 gradually decreases from the first-stage suction chamber 104 to the inducer chamber 105; an inducer chamber 144 is formed at the junction of the first-stage suction chamber 104 and the inducer chamber 105, and the conical end of the first-stage suction guide cone 143 extends into the inducer chamber 144. This design ensures that the pressurized medium in the first-stage suction chamber 104 will not radially impact the pump shaft 200 and the inducer 201. It smoothly diverts the medium in the first-stage suction chamber 104 from radial to axial flow into the inducer suction chamber 144. Furthermore, the first-stage suction guide cone 143 can form a double anti-cavitation structure with the inducer 201, effectively preventing the generation of medium vortices, improving hydraulic efficiency, and preventing cavitation, radial force generation, and vibration of the rotor assembly.

[0068] It should be noted that, as Figure 1 As shown, a spiral flow-blocking channel 145 is formed between the first-stage suction guide cone 143 and the pump shaft 200. This spiral flow-blocking channel 145 serves to block and reduce pressure, effectively preventing pressurized liquid in the first-stage suction chamber 104 from entering the drive-side mechanical seal chamber 103 and impacting its internal mechanical seal. At the same time, it effectively isolates impurities in the medium in the first-stage suction chamber 104 from entering the drive-side mechanical seal chamber 103 and damaging the mechanical seal, thereby ensuring the sealing of the pump body 100 on the drive side and effectively preventing leakage of the pumped medium along the pump shaft 200.

[0069] For example, such as Figure 1 and Figure 2 As shown, a secondary suction guide cone 146 is formed within the secondary suction chamber 109, through which the rotor assembly can pass. The outer wall of the secondary suction guide cone 146 smoothly transitions to the inner wall of the secondary suction chamber 109, and the outer diameter of the secondary suction guide cone 146 gradually decreases from the secondary suction chamber 109 towards the primary impeller chamber 108a. This design prevents the pressurized medium in the secondary suction chamber 109 from radially impacting the pump shaft 200, smoothly diverting the medium from radial to axial flow into the suction port of the primary impeller 203, preventing medium vortex generation, improving hydraulic efficiency, and preventing cavitation, radial force generation, and vibration of the rotor components.

[0070] For example, such as Figure 1As shown, the drive-side mechanical seal chamber 103 and the high-pressure side mechanical seal chamber 111 are each connected to a heat exchanger 600. The heat exchanger 600 has a first heat exchange medium channel and a second heat exchange medium channel. The first heat exchange medium channel is connected to the cooling water pipeline system 700, and the second heat exchange medium channel is connected to either the drive-side mechanical seal chamber 103 or the high-pressure side mechanical seal chamber 111 to form a circulation loop. During operation, the cooling water pipeline system 700 supplies cooling water to the heat exchanger 600. The mechanical seal is rotated by the pump shaft 200, thereby pressurizing the pumped medium in the drive-side mechanical seal chamber 103 and the high-pressure side mechanical seal chamber 111 and transporting it through pipelines to the heat exchanger 600 to exchange heat with the cooling water. After heat exchange, the pumped medium flows back to the drive-side mechanical seal chamber 103 and the high-pressure side mechanical seal chamber 111, independently flushing and cooling the internal mechanical seals. This effectively prevents damage to the mechanical seals from the pumped medium and ensures that the pumped medium does not mix with the cooling medium during discharge, maintaining a clean environment.

[0071] For example, such as Figure 1 and Figure 2 As shown, the drive-side mechanical seal chamber 103 is radially surrounded by a drive-side mechanical seal cooling chamber 147, which is adjacent to but not connected to it. The drive-side mechanical seal cooling chamber 147 is connected to the cooling water piping system 700. The high-pressure side mechanical seal chamber 111 is radially surrounded by a high-pressure side mechanical seal cooling chamber 148, which is adjacent to but not connected to it. The high-pressure side mechanical seal cooling chamber 148 is connected to the cooling water piping system 700. During operation, the cooling water piping system 700 supplies cooling water to the drive-side mechanical seal cooling chamber 147 and the high-pressure side mechanical seal cooling chamber 148, respectively, and exchanges heat with the pumped medium in the drive-side mechanical seal chamber 103 and the high-pressure side mechanical seal chamber 111, thereby achieving cooling and further improving the cooling effect of the mechanical seal.

[0072] For example, such as Figures 6 to 11As shown, the drive-side bearing housing 300 includes a first housing body 301 and a first housing cover 302, with the first housing cover 302 covering the top of the first housing body 301. The first housing cover 302 and the first housing body 301 together form a first outer shaft seal mounting position 303, a first sliding bearing lubricating oil chamber 304, a first sliding bearing mounting position 305, a first return oil chamber 306, a first inner shaft seal mounting position 307, and a first open chamber 308 arranged sequentially from the outside to the inside along the pump shaft 200 direction. A first outer shaft seal assembly 309 is mounted on the first outer shaft seal mounting position 303, a first sliding bearing assembly 310 is mounted on the first sliding bearing mounting position 305, and a first inner shaft seal assembly 308 is mounted on the first inner shaft seal mounting position 307. The inner shaft seal assembly 311 is connected to the first sliding bearing lubricating oil chamber 304 and the first return oil chamber 306 via a first return oil channel 312; the side wall of the first open chamber 308 is provided with a first open opening 313 communicating with the outside atmosphere; the bottom of the first sliding bearing lubricating oil chamber 304 is provided with a first corrugated heat exchange plate 314, and a first cooling cover 315 is provided on the first corrugated heat exchange plate 314, forming a first lubricating oil cooling chamber 316 between the first cooling cover 315 and the first corrugated heat exchange plate 314, which is connected to the cooling water pipeline system 700; the high-pressure side bearing housing 400 includes a second housing body 401 and a second housing cover 402, the second housing cover 402 covering the... Above the second housing 401; the second housing cover 402 and the second housing 401 together form an outer cover mounting position 403, a rolling bearing lubricating oil chamber 404, a rolling bearing mounting position 405, a second sliding bearing lubricating oil chamber 406, a second sliding bearing mounting position 407, a second return oil chamber 408, a second inner shaft seal mounting position 409, and a second open chamber 410 arranged sequentially from the outside to the inside along the direction of the pump shaft 200. A sealing cover 411 is installed on the outer cover mounting position 403, a rolling bearing assembly 412 is installed on the rolling bearing mounting position 405, a second sliding bearing assembly 413 is installed on the second sliding bearing mounting position 407, and a second inner shaft seal is installed on the second inner shaft seal mounting position 409. Component 414, the second sliding bearing lubricating oil chamber 406 and the second return oil chamber 408 are connected by a second return oil channel 415, and the second sliding bearing lubricating oil chamber 406 and the rolling bearing lubricating oil chamber 404 are connected by a third return oil channel 416; the side wall of the second open chamber 410 is provided with a second open opening 417 that communicates with the outside atmosphere; the bottom of the second sliding bearing lubricating oil chamber 406 is provided with a second corrugated heat exchange plate 418, the second corrugated heat exchange plate 418 is covered with a second cooling cover 419, the second cooling cover 419 and the second corrugated heat exchange plate 418 enclose a second lubricating oil cooling chamber 420, and the second lubricating oil cooling chamber 420 is connected to the cooling water pipeline system 700.

[0073] Therefore, based on the structural design of the drive-side bearing housing 300 and the high-pressure side bearing housing 400, the following advantages are achieved: First, both the drive-side bearing housing 300 and the high-pressure side bearing housing 400 adopt a split structure, consisting of a housing and a cover. This allows for quick inspection of the bearings' integrity without disassembling the entire bearing housing and bearings, saving time during bearing cycle inspections. It also facilitates the detection of the horizontal and lateral positioning of the rotor components and the pump body, ensuring assembly accuracy, stable pump operation, and extended pump lifespan. Furthermore, the housing and cover are processed separately, eliminating the need for a combined bearing housing assembly, reducing processing and inspection difficulties, increasing production speed and processing accuracy, and saving production and procurement costs. Second, by setting lubrication chambers and return oil chambers on both sides of each bearing, the lubrication chamber and return oil chamber... The bearing housing is connected by a return oil channel, allowing lubricating oil in the lubrication chamber to flow into the bearing from one side for lubrication and into the return oil chamber from the other side. The lubricating oil in the return oil chamber then flows back to the lubrication chamber through the return oil channel, forming a circulation that facilitates the renewal of lubricating oil within the bearing. Furthermore, a corrugated heat exchange plate and a cooling cover are installed at the bottom of the lubrication chamber, forming a cooling chamber. This cooling chamber is connected to a cooling water system, allowing cooling water to be injected into it to exchange heat with the lubricating oil in the bearing housing, reducing the oil temperature and thus cooling the bearing and extending its service life. Finally, the open design of the chamber promotes air circulation within the bearing housing, achieving heat dissipation, and also facilitates workers' inspection of leaks in the bearing housing and pump shaft for timely maintenance.

[0074] For example, such as Figure 6 and Figure 7 As shown, the first sliding bearing assembly 310 includes a first bearing housing 317 and a first sliding bearing 318. The first bearing housing 317 is fixed to the first sliding bearing mounting position 305 by screws, and the first sliding bearing 318 is mounted on the first bearing housing 317. The first sliding bearing 318 is mainly used to withstand the large radial load on the pump shaft 200.

[0075] For example, such as Figure 6 and Figure 7As shown, the first sliding bearing lubrication chamber 304 is provided with a first oil slinger ring 319 and a first baffle 320. The first oil slinger ring 319 is sleeved on the pump shaft 200 and rotates in friction with the pump shaft 200. The first oil slinger ring 319 is close to the first sliding bearing 318, and the first baffle 320 is fixed to the first bearing seat 317 by screws and blocks the side of the first oil slinger ring 319 away from the first sliding bearing 318. In this way, when the pump shaft 200 rotates, the friction drives the first oil slinger ring 319 to rotate. At this time, the first oil slinger ring 319 can lift the lubricating oil at the bottom of the first sliding bearing lubrication chamber 304 to the top of the pump shaft 200, so that the lubricating oil flows into the interior of the first sliding bearing 318 to achieve a lubrication effect. At the same time, the first baffle 320 can prevent the first oil slinger ring 319 from moving away from the first sliding bearing 318, ensuring that the lubricating oil can flow smoothly into the interior of the first sliding bearing 318. It should also be noted that since the lubricating oil is carried into the first sliding bearing 318 by the first oil slinger ring 319, the level of the lubricating oil can be lower than the horizontal position of the first sliding bearing 318.

[0076] For example, such as Figure 6 and Figure 7 As shown, in order to form a reliable sealed cavity in the drive-side bearing housing 300, both the first outer shaft seal assembly 309 and the first inner shaft seal assembly 311 include a first oil baffle ring 321, a first oil blocking ring 322, and a first dust cover 323 sleeved on the pump shaft 200. The first oil baffle ring 321 is fixed to the first outer shaft seal mounting position 303 or the first inner shaft seal mounting position 307 by screws. The first oil baffle ring 321 has a first receiving groove on the side away from the first sliding bearing lubricating oil chamber 304 or the first return oil chamber 306, which allows the first oil blocking ring 322 to be embedded. The first dust cover 323 is covered on the first receiving groove and fastened to the pump shaft 200 by screws. The first oil-blocking ring 321 blocks and throttles the lubricating oil for the first time, and the first oil-blocking ring 322 blocks and throttles the lubricating oil for the second time, which can effectively prevent lubricating oil leakage; the first dust cover 323 can effectively prevent external dust and other impurities from entering the sealed cavity of the drive-side bearing housing 300 and contaminating the lubricating oil.

[0077] For example, such as Figures 6 to 8As shown, the drive-side bearing housing 300 is provided with a first X-axis vibration probe interface 324, a first Y-axis vibration probe interface 325, a first Z-axis vibration probe interface 326, and a first temperature probe interface 327. A first X-axis vibration probe for detecting the X-axis vibration of the drive-side bearing housing 300 is installed on the first X-axis vibration probe interface 324; a first Y-axis vibration probe for detecting the Y-axis vibration of the drive-side bearing housing 300 is installed on the first Y-axis vibration probe interface 325; a first Z-axis vibration probe for detecting the Z-axis vibration of the drive-side bearing housing 300 is installed on the first Z-axis vibration probe interface 326; and a first temperature probe for detecting the oil temperature inside the first return oil chamber 306 is installed on the first temperature probe interface 327. Therefore, by installing a first temperature detection probe, a first X-axis vibration detection probe, a first Y-axis vibration probe, and a first Z-axis vibration probe on the drive-side bearing housing 300, the operating temperature of the bearing (which can be reflected by the oil temperature in the first return oil chamber 306) and the vibration of the pump in the X, Y, and Z directions can be detected and monitored in real time, thereby judging the pump's operating status in real time, ensuring the pump's stable operation, and improving the pump's operational safety and reliability.

[0078] For example, such as Figure 9 and Figure 10 As shown, the second sliding bearing assembly 413 includes a second bearing housing 421 and a second sliding bearing 422. The second bearing housing 421 is fixed to the second sliding bearing mounting position 407 by screws, and the second sliding bearing 422 is mounted on the second bearing housing 421. The second sliding bearing 422 is mainly used to withstand the large radial load on the pump shaft 200.

[0079] For example, such as Figure 9 and Figure 10As shown, the second sliding bearing lubrication chamber 406 is provided with a second oil slinger ring 423 and a second baffle 424. The second oil slinger ring 423 is sleeved on the pump shaft 200 and rotates in friction with the pump shaft 200. The second oil slinger ring 423 is close to the second sliding bearing 422. The second baffle 424 is fixed to the second bearing seat 421 by screws and blocks the side of the second oil slinger ring 423 away from the second sliding bearing 422. In this way, when the pump shaft 200 rotates, the friction drives the second oil slinger ring 423 to rotate. At this time, the second oil slinger ring 423 can lift the lubricating oil at the bottom of the second sliding bearing lubrication chamber 406 to the top of the pump shaft 200, so that the lubricating oil flows into the interior of the second sliding bearing 422 to achieve a lubrication effect. At the same time, the second baffle 424 can prevent the second oil slinger ring 423 from moving away from the second sliding bearing 422, ensuring that the lubricating oil can flow smoothly into the interior of the second sliding bearing 422. It should also be noted that since the lubricating oil is carried into the second sliding bearing 422 by the second oil slinger ring 423, the level of the lubricating oil can be lower than the horizontal position of the second sliding bearing 422.

[0080] For example, such as Figure 9 and Figure 10 As shown, the rolling bearing assembly 412 includes a rolling bearing 425 and a clamping member 426. A limiting ring 427 is formed on the side of the rolling bearing mounting position 405 near the lubrication chamber 406 of the second sliding bearing. The clamping member 426 is fixed to the side of the rolling bearing mounting position 405 away from the lubrication chamber 406 of the second sliding bearing by screws. The outer ring of the rolling bearing 425 is pressed between the limiting ring 427 and the clamping member 426, facilitating assembly. The rolling bearing 425 is mainly used to bear the axial and radial loads of the pump shaft 200. Furthermore, to improve the axial and radial load capacity of the rolling bearing 425, two rolling bearings 425 are stacked along the direction of the pump shaft 200.

[0081] For example, such as Figure 9 and Figure 10As shown, the rolling bearing lubrication chamber 404 is provided with a third oil slinger ring 428, an oil ring seat 429, and a clamping nut 430. The oil ring seat 429 is sleeved on the pump shaft 200. The clamping nut 430 is threaded to the end of the pump shaft 200 and presses the oil ring seat 429 and the inner ring of the rolling bearing 425 onto the shoulder of the pump shaft 200. The third oil slinger ring 428 is sleeved on the oil ring seat 429 and rotates rubbing against the oil ring seat 429. The outer circumference of the oil ring seat 429 is provided with a limiting groove 431 that cooperates with the third oil slinger ring 428. Thus, when the pump shaft 200 rotates, friction drives the third oil slinger ring 428 to rotate. At this time, the third oil slinger ring 428 can lift the lubricating oil at the bottom of the rolling bearing lubrication chamber 404 to the top of the oil ring seat 429, so that the lubricating oil flows into the rolling bearing 425 through the oil ring seat 429 to achieve a lubrication effect. At the same time, the limiting groove 431 can prevent the second oil slinger ring 423 from moving away from the rolling bearing 425, ensuring that the lubricating oil can flow smoothly into the rolling bearing 425. It should also be noted that since the lubricating oil is carried into the rolling bearing 425 by the third oil slinger ring 428, the lubricating oil level can be lower than the horizontal position of the rolling bearing 425.

[0082] For example, such as Figure 9 and Figure 10 As shown, to ensure a reliable sealed cavity in the high-pressure side bearing housing 400, the second inner shaft seal assembly 414 includes a second oil baffle ring 432, a second oil blocking ring 433, and a second dust cover 434 fitted onto the pump shaft 200. The second oil baffle ring 432 is fixed to the second inner shaft seal mounting position 409 by screws. The second oil baffle ring 432 has a second receiving groove on the side away from the second sliding bearing lubrication chamber 406, allowing the second oil blocking ring 433 to be embedded. The second dust cover 434 covers the second receiving groove and is fastened to the pump shaft 200 by screws. The second oil baffle ring 432 performs a first-stage blocking and throttling of the lubricating oil, and the second oil blocking ring 433 performs a second-stage blocking and throttling of the lubricating oil, effectively preventing lubricating oil leakage. The second dust cover 434 effectively prevents external dust and other impurities from entering the sealed cavity of the high-pressure side bearing housing 400 and contaminating the lubricating oil.

[0083] For example, such as Figure 9 and Figure 11As shown, the high-pressure side bearing housing 400 is provided with a second X-axis vibration probe interface 435, a second Y-axis vibration probe interface 436, a second Z-axis vibration probe interface 437, and a second temperature probe interface 438. A second X-axis vibration probe for detecting the X-axis vibration of the drive-side bearing housing 300 is installed on the second X-axis vibration probe interface 435; a second Y-axis vibration probe for detecting the Y-axis vibration of the drive-side bearing housing 300 is installed on the second Y-axis vibration probe interface 436; a second Z-axis vibration probe for detecting the Z-axis vibration of the drive-side bearing housing 300 is installed on the second Z-axis vibration probe interface 437; and a second temperature probe for detecting the oil temperature inside the second return oil chamber 408 is installed on the second temperature probe interface 438. Therefore, by installing a second temperature detection probe, a second X-axis vibration detection probe, a second Y-axis vibration probe, and a second Z-axis vibration probe on the high-pressure side bearing housing 400, the operating temperature of the bearing (which can be reflected by the oil temperature in the second return oil chamber 408) and the vibration of the pump in the X, Y, and Z directions can be detected and monitored in real time, thereby judging the pump's operating status in real time, ensuring the pump's stable operation, and improving the pump's operational safety and reliability.

[0084] For example, such as Figures 6 to 11 As shown, both the drive-side bearing housing 300 and the high-pressure-side bearing housing 400 are provided with reinforcing ribs (330, 439) to enhance the structural strength of the bearing housing.

[0085] For example, such as Figure 6 and Figure 9 As shown, the top of the first oil return chamber 306 and the second oil return chamber 408 are both equipped with exhaust hoods (331, 440) to prevent the lubricating oil from leaking due to increased internal pressure caused by the rise in bearing housing temperature.

[0086] For example, such as Figure 6 and Figure 9As shown, the first housing 301 and the second housing 401 have axially protruding first stop half-rings 328 on their end faces facing the pump body 101; the first housing cover 302 and the second housing cover 402 have axially protruding second stop half-rings 329 on their end faces facing the pump cover 102; the first stop half-rings 328 and the second stop half-rings 329 cooperate to form a stop ring; the pump body 101 has lifting mechanisms 800 that cooperate with the first stop half-rings 328 on its two end faces; and the pump cover 102 has mechanisms that cooperate with the second stop half-rings 329 on its two end faces. The semi-circular stop 149; thus, the stop ring formed by the cooperation of the first stop semi-circular stop 328 and the second stop semi-circular stop 329 can form a circumferential ring cooperation with the lifting mechanism 800 on the pump body 100 and the semi-circular stop 149, so that the bearing housing can form an integral part with the pump body 101 and the pump cover 102. During assembly, the assembly quality and assembly accuracy of the rotor components can be guaranteed, and the rigidity of the bearing housing and the pump body 101 is also guaranteed. At the same time, during the operation of the pump, since the upper surface of the end of the bearing housing cooperates with the pump cover 102, it forms an end face support force, which effectively solves the problem that the bearing housing is prone to warping and loosening.

[0087] For example, such as Figures 12 to 14As shown, the lifting mechanism 800 includes a lifting cone ring 801 and an adjusting screw 802. The lifting cone ring 801 is provided with a semi-ring connecting portion 803 and a semi-ring stop portion 804. The semi-ring stop portion 804 is formed at the upper end of the semi-ring connecting portion 803, and the semi-ring stop portion 804 abuts against the bottom of the first stop semi-ring 328. The semi-ring stop portion 804 is provided with a semi-ring protrusion 805 on the side facing the pump body 101, and the outer peripheral surface of the semi-ring protrusion 805 is a first conical surface 806. The end face of the pump body 101 is provided with a semi-ring recess 150 for mounting the lifting cone ring 801. The lower side of the semi-ring recess 150 is a second conical surface 151 that slides with the first conical surface 806. The semi-ring connecting portion 803 is provided with a plurality of mounting holes 807 evenly distributed. The end face of 1 is provided with threaded holes 152 corresponding to the mounting holes 807. The adjusting screw 802 passes through the mounting holes 807 and connects to the threaded holes 152. Thus, through the structural design of the lifting mechanism 800, the semi-circular stop portion 804 on the lifting cone ring 801 abuts against the bottom of the first stop semi-circular 328 on the end face of the housing, so that the first conical surface 806 on the lifting cone ring 801 slides into contact with the second conical surface 151 on the pump body 101. By utilizing the threaded adjustment relationship between the adjusting screw 802 and the threaded hole on the pump body 101, when the adjusting screw 802 is screwed into or out of the threaded hole, it can drive the lifting cone ring 801 to raise or lower the pump bearing housing, change the relative position of the pump bearing housing and the pump body 100, thereby adjusting the height position of the pump shaft 200 and adjusting the concentricity of the rotor and the pump cavity. The lifting mechanism 800 has a simple structure and is easy to operate. It can improve the phenomenon of pump rotor sagging caused by assembly errors due to part machining errors and pump rotor sagging caused by corrosion of the bearing housing stop after long-term use. It ensures the concentricity of the rotor and the pump chamber, while improving the rotor's running friction and misalignment vibration, and extending the pump's service life.

[0088] For example, the mounting hole 807 is a waist-shaped countersunk hole, and the length direction of the waist-shaped countersunk hole is consistent with the height direction of the pump body 100, so as to accommodate the adjustment of the lifting cone ring 801 in the height direction.

[0089] For example, such as Figures 12 to 14 As shown, the pump body 100 and the drive-side bearing housing 300, as well as the pump body 100 and the high-pressure-side bearing housing 400, are connected by multiple bolts 158. At least one of the bolts 158 abuts against the bottom of the lifting cone ring 801 to enhance the supporting capacity of the lifting cone ring 801 for the bearing housing. Furthermore, the lower outer periphery of the semi-ring connecting portion 803 is provided with a bolt clearance groove 808; the bolt clearance groove 808 engages with and abuts against the bolt 158.

[0090] For example, such as Figure 5 As shown, the pump body 100 is provided with shaft seal covers 153 at both ends. The shaft seal covers 153 cover the outer port of the drive-side mechanical seal chamber 103 and the outer port of the high-pressure side mechanical seal chamber 111, respectively. At least two O-rings 157 are provided between the shaft seal cover 153 and the pump body 100. Both the drive-side mechanical seal chamber 103 and the high-pressure side mechanical seal chamber 111 are provided with mechanical seals 154 sleeved on the pump shaft 200. The mechanical seals 154 can form a sealed connection structure between the pump shaft 200 and the shaft seal cover 153.

[0091] For example, such as Figure 5 As shown, to avoid frictional wear on the pump shaft 200 caused by the throttling ring 118 and the flow-blocking ring 119, a throttling sleeve 204 and a flow-blocking sleeve 205 are fixedly sleeved at the corresponding positions of the pump shaft 200 and the throttling ring 118, the mechanical seal pressure relief chamber 110, the flow-blocking ring 119, the high-pressure side mechanical seal chamber 111, the mechanical seal 154, and the shaft seal cover 153. The throttling ring 118 is sleeved on the throttling sleeve 204 and forms a throttling channel 155 between the throttling sleeve 118 and the throttling sleeve 204. The flow-blocking ring 119 is sleeved on the flow-blocking sleeve 205 and forms a flow-blocking channel 156 between the throttling sleeve 205 and the flow-blocking sleeve 205. Furthermore, in order to improve the dual flow-blocking and pressure-reducing effect of the throttling channel 155 and the flow-blocking channel 156, the outer periphery of the throttling sleeve 204 is provided with a spiral groove, which forms a spiral throttling channel 155 with the inner circumferential surface of the throttling port ring 118; the outer periphery of the flow-blocking sleeve 205 is provided with a spiral groove, which forms a spiral flow-blocking channel 156 with the inner circumferential surface of the flow-blocking port ring 119.

[0092] For example, such as Figure 5 As shown, in order to better connect and fix the throttling sleeve 204 and the flow-blocking sleeve 205 to the pump shaft 200, a clamping sleeve 206, a water-blocking nut 207, and a locking nut 208 are also sleeved on the end of the pump shaft 200 away from the throttling sleeve 204. The water-blocking nut 207 and the locking nut 208 are respectively threaded to the pump shaft 200. When the water-blocking nut 207 and the locking nut 208 are both screwed toward the clamping sleeve 206, the water-blocking nut 207 presses the clamping sleeve 206, the flow-blocking sleeve 205, and the throttling sleeve 204 onto the shoulder of the pump shaft 200 in sequence, and the locking nut 208 presses onto the water-blocking nut 207.

[0093] For example, such as Figure 5As shown, in order to prevent the pumped medium in the high-pressure side mechanical seal chamber 111 from leaking from the fitting clearance between the flow-blocking sleeve 205, the clamping sleeve 206 and the pump shaft 200, the flow-blocking sleeve 205 passes through the shaft seal cover 153, and an O-ring seal 209 is clamped at the joint between the flow-blocking sleeve 205 and the clamping sleeve 206, and the inner ring of the O-ring seal 209 abuts tightly against the outer circumferential surface of the pump shaft 200.

[0094] For example, such as Figure 1 As shown, the pump base 500 is provided with support feet 501 for fixing and supporting the pump body 100. A support foot cooling chamber is provided inside the support foot 501, and the support foot cooling chamber is connected to the cooling water pipeline system 700. During operation, the cooling water pipeline system 700 can supply cooling water to the support foot cooling chamber, thereby cooling the pump's support feet and ensuring that the support feet, pump body 101, and support foot mounting surface do not deform when the pump is conveying high-temperature media, thus ensuring stable pump operation and improving pump service life.

[0095] It should also be noted that the cooling water pipeline system 700 mainly includes a cooling water source (such as a water tank or a direct water supply source), an inlet main pipe, an outlet main pipe, and inlet and outlet branch pipes and valves that are respectively connected to the drive-side mechanical seal cooling chamber 147, the high-pressure side mechanical seal cooling chamber 148, the first lubricating oil cooling chamber 316, the second lubricating oil cooling chamber 420, the support foot cooling chamber, and the heat exchanger 600.

[0096] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A multi-stage split-case pump with a long lifespan, comprising a pump body, a pump shaft, a drive-side bearing housing, a high-pressure-side bearing housing, and a pump base; the pump body is composed of a pump body and a pump cover, the pump shaft is rotatably mounted on the pump body with its two ends extending from both ends of the pump body; the drive-side bearing housing is fixedly installed on the drive end of the pump body and connected to the pump shaft; the high-pressure-side bearing housing is fixedly installed on the high-pressure end of the pump body and connected to the pump shaft; characterized in that: The pump body, arranged sequentially from its drive end to the high-pressure end, includes a drive-side mechanical seal chamber, a first-stage suction chamber, an inducer chamber for housing an inducer, a positive impeller chamber for housing a positive impeller, an impeller pressure relief chamber, a negative impeller chamber for housing a negative impeller, a secondary suction chamber, a mechanical seal pressure relief chamber, and a high-pressure side mechanical seal chamber. The pump body inlet, the first-stage suction chamber, and the inducer chamber are sequentially connected. The positive impeller chamber includes a first-stage positive impeller chamber, several secondary positive impeller chambers, and a final-stage positive impeller chamber, all sequentially connected. The first-stage negative impeller chamber is connected to the secondary suction chamber. The upper end of the final-stage positive impeller chamber is connected to the upper end of the secondary suction chamber via a pump cover transition channel, and the lower end of the final-stage positive impeller chamber is connected to the lower end of the secondary suction chamber via a pump body transition channel. The pump cover transition channel and the pump body transition channel are connected to the pump body. The impellers are arranged symmetrically around the shaft. The impeller chamber includes a first-stage impeller chamber, several secondary impeller chambers, and a final-stage impeller chamber connected in sequence. The first-stage impeller chamber is connected to the secondary suction chamber, and the final-stage impeller chamber is connected to the outlet of the pump body. The inducer, the positive impeller, and the impellers are all fixedly mounted on the pump shaft. The number of positive impellers and the number of impellers are equal and arranged symmetrically around the impeller pressure relief chamber. A flow passage is formed between two adjacent positive impeller chambers and between two adjacent impeller chambers. The radial cross-sectional shape of the flow passage is a standard circle. The impeller pressure relief chamber is connected to the last secondary positive impeller chamber through a first pressure relief pipe. The mechanical seal pressure relief chamber is connected to the first-stage positive impeller chamber through a second pressure relief pipe. A wear ring mounting position is provided in the inducer wheel chamber, between the inducer wheel chamber and the positive impeller chamber, between two adjacent positive impeller chambers, between the final stage positive impeller chamber and the impeller pressure relief chamber, between the impeller pressure relief chamber and the final stage reverse impeller chamber, between two adjacent reverse impeller chambers, between the reverse impeller chamber and the secondary suction chamber, between the secondary suction chamber and the mechanical seal pressure relief chamber, and between the mechanical seal pressure relief chamber and the high-pressure side mechanical seal chamber. The wear ring mounting position corresponding to the inducer wheel chamber is provided with an inducer wheel wear ring that is clearance-fitted with the inducer wheel. The wear ring mounting position corresponding to the inducer wheel chamber and the two adjacent positive impeller chambers are provided with... Hub rings that fit with the clearance between the impeller hubs on both sides are respectively provided at the corresponding ring mounting positions between the chambers, between the final stage positive impeller chamber and the impeller pressure relief chamber, between the impeller pressure relief chamber and the final stage reverse impeller chamber, between two adjacent reverse impeller chambers, and between the reverse impeller chamber and the secondary suction chamber; a throttling ring that fits with the pump shaft clearance is provided at the corresponding ring mounting position between the secondary suction chamber and the mechanical seal pressure relief chamber; and a flow-blocking ring that fits with the pump shaft clearance is provided at the corresponding ring mounting position between the mechanical seal pressure relief chamber and the high-pressure side mechanical seal chamber.

2. The multi-stage split-case pump with a long lifespan according to claim 1, characterized in that: Between two adjacent impeller chambers, a sequentially connected impeller pressure chamber, an impeller annular chamber, and impeller suction chamber are formed. These three chambers constitute the flow channel. The impeller annular chamber surrounds the radially outer sides of both the impeller pressure chamber and the impeller suction chamber. The impeller pressure chamber and the impeller suction chamber are separated by corresponding inlet ring mounting positions. The impeller pressure chamber surrounds the outer periphery of the previous impeller chamber and is connected to... The positive impeller chamber is connected; the positive impeller suction chamber is located on the axial side of the next positive impeller chamber and is connected to it; the radial outer side of the last-stage positive impeller chamber is surrounded by a positive impeller volute chamber, the upper end of which is connected to the upper end of the secondary suction chamber through a pump cover transition channel, and the lower end of which is connected to the lower end of the secondary suction chamber through a pump body transition channel; a reverse impeller pressure chamber and a reverse impeller are formed between two adjacent reverse impeller chambers in sequence. The flow passage consists of an annular chamber and a reverse impeller suction chamber. The reverse impeller pressure chamber, the reverse impeller annular chamber, and the reverse impeller suction chamber constitute the flow passage. The reverse impeller annular chamber surrounds the radially outer sides of the reverse impeller pressure chamber and the reverse impeller suction chamber. The reverse impeller pressure chamber and the reverse impeller suction chamber are separated by corresponding inlet ring mounting positions. The reverse impeller pressure chamber surrounds the outer periphery of the previous reverse impeller chamber and communicates with it. The reverse impeller suction chamber is located on one axial side of the next reverse impeller chamber. It is connected to the reverse impeller chamber; the radial outer side of the final stage reverse impeller chamber is surrounded by a reverse impeller volute chamber, which is connected to the outlet of the pump body; both the positive impeller volute chamber and the reverse impeller volute chamber have multiple circumferentially distributed volute chamber guide vanes; both the positive impeller suction chamber and the reverse impeller suction chamber have multiple circumferentially distributed suction chamber guide vanes; both the positive impeller volute chamber and the reverse impeller volute chamber have multiple circumferentially distributed volute chamber guide vanes.

3. The long-life-cycle multi-stage split-case pump according to claim 1, characterized in that: The inducer ring, hub ring, throttling ring, and flow-blocking ring are all composed of two half-rings, which are joined together to form a circular ring. Each half-ring has symmetrical radial protrusions on both sides near its open end. The upper surface of the radial protrusion is flush with the end face of the open end of the half-ring, and the lower surface of the radial protrusion is a horizontal positioning surface. The end face of the radial protrusion away from the half-ring is a radial positioning surface. The outer circumferential surface of the half-ring near the radial protrusion is an anti-rotation surface. The anti-rotation surfaces on both sides of the half-ring are parallel to each other. Each ring mounting position has a mounting base surface that respectively conforms to the horizontal positioning surface, the radial positioning surface, and the anti-rotation surface. The radial protrusion has a countersunk hole penetrating its upper and lower surfaces. The mounting base surface conforming to the horizontal positioning surface has a threaded hole opposite to the countersunk hole, and a screw passes through the countersunk hole and connects to the threaded hole.

4. The long-life-cycle multi-stage split-case pump according to claim 1, characterized in that: A first-stage suction guide cone is formed in the first-stage suction chamber, through which the pump shaft can pass; the outer wall surface of the first-stage suction guide cone smoothly transitions to the inner wall surface of the first-stage suction chamber, and the outer diameter of the first-stage suction guide cone gradually decreases from the first-stage suction chamber to the inducer chamber; a second-stage suction guide cone is formed in the second-stage suction chamber, through which the rotor assembly can pass; the outer wall surface of the second-stage suction guide cone smoothly transitions to the inner wall surface of the second-stage suction chamber, and the outer diameter of the second-stage suction guide cone gradually decreases from the second-stage suction chamber to the first-stage impeller chamber.

5. The long-life-cycle multi-stage split-case pump according to claim 1, characterized in that: The drive-side mechanical seal chamber and the high-pressure side mechanical seal chamber are each connected to a heat exchanger. The heat exchanger is provided with a first heat exchange medium channel and a second heat exchange medium channel. The first heat exchange medium channel is connected to the cooling water pipeline system, and the second heat exchange medium channel is connected to the drive-side mechanical seal chamber or the high-pressure side mechanical seal chamber to form a circulation loop.

6. The long-life-cycle multi-stage split-case pump according to claim 1, characterized in that: The drive-side mechanical seal chamber is surrounded radially by a drive-side mechanical seal cooling chamber that is adjacent to it but not connected to it, and the drive-side mechanical seal cooling chamber is connected to the cooling water pipeline system; the high-pressure side mechanical seal chamber is surrounded radially by a high-pressure side mechanical seal cooling chamber that is adjacent to it but not connected to it, and the high-pressure side mechanical seal cooling chamber is connected to the cooling water pipeline system.

7. The long-life-cycle multi-stage split-case pump according to claim 1, characterized in that: The drive-side bearing housing includes a first housing body and a first housing cover, with the first housing cover covering the top of the first housing body. The first housing cover and the first housing body together form a first outer shaft seal mounting position, a first sliding bearing lubricating oil chamber, a first sliding bearing mounting position, a first return oil chamber, a first inner shaft seal mounting position, and a first open chamber arranged sequentially from the outside to the inside along the pump shaft direction. A first outer shaft seal assembly is installed on the first outer shaft seal mounting position, a first sliding bearing assembly is installed on the first sliding bearing mounting position, and a first inner shaft seal assembly is installed on the first inner shaft seal mounting position. The first sliding bearing lubricating oil chamber and the first return oil chamber are connected through a first return oil channel. The side wall of the first open chamber is provided with a first opening that communicates with the outside atmosphere. A first corrugated heat exchange plate is provided at the bottom of the first sliding bearing lubricating oil chamber. A first cooling cover is provided on the first corrugated heat exchange plate, and the first cooling cover and the first corrugated heat exchange plate enclose a first lubricating oil cooling chamber, which is connected to a cooling water pipeline system. The high-pressure side bearing housing includes a second housing body and a second housing cover, with the second housing cover positioned above the second housing body. The second housing cover and the second housing body together form a series of components arranged sequentially from the outside to the inside along the pump shaft direction: an outer cover mounting position, a rolling bearing lubricating oil chamber, a rolling bearing mounting position, a second sliding bearing lubricating oil chamber, a second sliding bearing mounting position, a second oil return chamber, a second inner shaft seal mounting position, and a second open chamber. A sealing cover is installed on the outer cover mounting position, a rolling bearing assembly is installed on the rolling bearing mounting position, a second sliding bearing assembly is installed on the second sliding bearing mounting position, and the second inner shaft seal... A second inner shaft seal assembly is installed at the mounting position. The second sliding bearing lubricating oil chamber and the second return oil chamber are connected through a second return oil channel, and the second sliding bearing lubricating oil chamber and the rolling bearing lubricating oil chamber are connected through a third return oil channel. The side wall of the second open chamber is provided with a second opening that communicates with the outside atmosphere. The bottom of the second sliding bearing lubricating oil chamber is provided with a second corrugated heat exchange plate. A second cooling cover is provided on the second corrugated heat exchange plate. The second cooling cover and the second corrugated heat exchange plate enclose a second lubricating oil cooling chamber, which is connected to a cooling water pipeline system. Both the first and second oil return chambers are equipped with exhaust hoods at their tops.

8. The long-life-cycle multi-stage split-case pump according to claim 7, characterized in that: The first sliding bearing assembly includes a first bearing housing and a first sliding bearing. The first bearing housing is fixed to the first sliding bearing mounting position by screws, and the first sliding bearing is mounted on the first bearing housing. The lubrication oil chamber of the first sliding bearing is provided with a first oil slinger ring and a first baffle. The first oil slinger ring is sleeved on the pump shaft and rotates in friction with the pump shaft. The first oil slinger ring is close to the first sliding bearing, and the first baffle is fixed to the first bearing housing by screws and blocks the first oil slinger ring from the side away from the first sliding bearing. The second sliding bearing assembly includes a second bearing housing and a second sliding bearing. The second bearing housing is fixed to the second sliding bearing mounting position by screws, and the second sliding bearing is mounted on the second bearing housing. The lubrication oil chamber of the second sliding bearing is provided with a second oil slinger ring and a second baffle. The second oil slinger ring is sleeved on the pump shaft and rotates in friction with the pump shaft. The second oil slinger ring is close to the second sliding bearing, and the second baffle is fixed to the second bearing housing by screws and blocks the second oil slinger ring on the side away from the second sliding bearing. The rolling bearing assembly includes a rolling bearing and a clamping member. A limiting ring is formed on the side of the rolling bearing mounting position near the lubrication chamber of the second sliding bearing. The clamping member is fixed by screws on the side of the rolling bearing mounting position away from the lubrication chamber of the second sliding bearing. The outer ring of the rolling bearing is pressed between the limiting ring and the clamping member. Two rolling bearings are stacked along the pump shaft direction. A third oil slinger ring, an oil ring seat, and a clamping nut are provided in the lubrication chamber of the rolling bearing. The oil ring seat is sleeved on the pump shaft. The clamping nut is threaded to the end of the pump shaft and presses the oil ring seat and the inner ring of the rolling bearing onto the pump shaft shoulder. The third oil slinger ring is sleeved on the oil ring seat and rotates friably with the oil ring seat. The outer circumference of the oil ring seat is provided with a limiting groove that mates with the third oil slinger ring.

9. The long-life-cycle multi-stage split-case pump according to claim 7, characterized in that: Both the first outer shaft seal assembly and the first inner shaft seal assembly include a first oil baffle ring, a first oil blocking ring, and a first dust cover sleeved on the pump shaft. The first oil baffle ring is fixed to the first outer shaft seal mounting position or the first inner shaft seal mounting position by screws. The first oil baffle ring has a first receiving groove on the side away from the first sliding bearing lubricating oil chamber or the first return oil chamber, which allows the first oil blocking ring to be embedded. The first dust cover is placed on the first receiving groove and is fastened to the pump shaft by screws. The second inner shaft seal assembly includes a second oil baffle ring, a second oil blocking ring, and a second dust cover fitted on the pump shaft. The second oil baffle ring is fixed to the second inner shaft seal mounting position by screws. The second oil baffle ring has a second receiving groove on the side away from the lubricating oil chamber of the second sliding bearing, which allows the second oil blocking ring to be embedded. The second dust cover is placed on the second receiving groove and fastened to the pump shaft by screws.

10. The long-life-cycle multi-stage split-case pump according to claim 7, characterized in that: The first housing and the second housing are respectively provided with axially protruding first stop half-rings on their end faces facing the pump body; the first housing cover and the second housing cover are respectively provided with axially protruding second stop half-rings on their end faces facing the pump cover; the first stop half-rings and the second stop half-rings cooperate to form a stop ring; a lifting mechanism that cooperates with the first stop half-ring is respectively installed on the end faces of the pump body; the end faces of the pump cover are provided with half-ring stopes that cooperate with the second stop half-rings; the lifting mechanism includes a lifting cone ring and an adjusting screw, the lifting cone ring is provided with a half-ring connecting part and a half-ring stop part, the half-ring stop part is formed at the upper end of the half-ring connecting part, and the half-ring stop part cooperates with the first stop half-ring. The bottom of the ring abuts against each other; the semi-ring stop portion facing the pump body has a semi-ring protrusion, the outer circumferential surface of which is a first conical surface; the end face of the pump body has a semi-ring recess for mounting the lifting cone ring, the lower side of which is a second conical surface that slides with the first conical surface; the semi-ring connecting portion has multiple mounting holes evenly distributed, and the end face of the pump body has threaded holes corresponding to the mounting holes one by one; the adjusting screw passes through the mounting hole and connects to the threaded hole; when the adjusting screw is screwed in or out of the threaded hole, it can drive the lifting cone ring to raise or lower the pump bearing housing, change the relative position of the pump bearing housing and the pump body, and thus adjust the height position of the pump shaft.

11. The long-life-cycle multi-stage split-case pump according to any one of claims 7 to 10, characterized in that: The drive-side bearing housing is provided with a first X-axis vibration probe interface, a first Y-axis vibration probe interface, a first Z-axis vibration probe interface, and a first temperature probe interface. A first X-axis vibration probe for detecting X-axis vibration of the drive-side bearing housing is installed on the first X-axis vibration probe interface; a first Y-axis vibration probe for detecting Y-axis vibration of the drive-side bearing housing is installed on the first Y-axis vibration probe interface; a first Z-axis vibration probe for detecting Z-axis vibration of the drive-side bearing housing is installed on the first Z-axis vibration probe interface; and a first temperature probe for detecting the oil temperature in the first return oil chamber is installed on the first temperature probe interface. The high-pressure side bearing housing is provided with a second X-axis vibration probe interface, a second Y-axis vibration probe interface, a second Z-axis vibration probe interface, and a second temperature probe interface. A second X-axis vibration probe for detecting X-axis vibration of the drive-side bearing housing is installed on the second X-axis vibration probe interface. A second Y-axis vibration probe for detecting Y-axis vibration of the drive-side bearing housing is installed on the second Y-axis vibration probe interface. A second Z-axis vibration probe for detecting Z-axis vibration of the drive-side bearing housing is installed on the second Z-axis vibration probe interface. A second temperature probe for detecting the oil temperature in the second return oil chamber is installed on the second temperature probe interface.

12. The long-life-cycle multi-stage split-case pump according to claim 1, characterized in that: The pump body has shaft seal covers at both ends, which cover the outer ports of the drive-side mechanical seal chamber and the high-pressure side mechanical seal chamber, respectively. At least two O-rings are provided between the shaft seal covers and the pump body. Both the drive-side mechanical seal chamber and the high-pressure side mechanical seal chamber are provided with mechanical seals fitted onto the pump shaft. The mechanical seals can form a sealed connection structure between the pump shaft and the shaft seal covers.

13. The long-life-cycle multi-stage split-case pump according to claim 12, characterized in that: The pump shaft is fixedly fitted with a throttling sleeve and a flow-blocking sleeve at positions corresponding to the throttling orifice ring, the mechanical seal pressure relief chamber, the flow-blocking orifice ring, the high-pressure side mechanical seal chamber, the mechanical seal, and the shaft seal cover. The throttling orifice ring is fitted onto the throttling sleeve and forms a spiral throttling channel with the throttling sleeve. The flow-blocking orifice ring is fitted onto the flow-blocking sleeve and forms a spiral flow-blocking channel with the flow-blocking sleeve.

14. The long-life-cycle multi-stage split-case pump according to claim 13, characterized in that: The pump shaft is further fitted with a clamping sleeve, a water-blocking nut, and a locking nut at the end of the flow-blocking sleeve away from the throttling sleeve. The water-blocking nut and the locking nut are threaded to the pump shaft. When the water-blocking nut and the locking nut are both screwed toward the clamping sleeve, the water-blocking nut presses the clamping sleeve, the flow-blocking sleeve, and the throttling sleeve onto the shoulder of the pump shaft in sequence, and the locking nut presses onto the water-blocking nut. The flow-blocking sleeve passes through the shaft seal cover, and an O-ring is clamped at the joint between the flow-blocking sleeve and the clamping sleeve. The inner ring of the O-ring tightly abuts against the outer circumferential surface of the pump shaft.

15. The long-life-cycle multi-stage split-case pump according to claim 1, characterized in that: The pump base is provided with support feet for fixing and supporting the pump body. The support feet are provided with support foot cooling chambers, which are connected to the cooling water pipeline system.

Images