Pressure-adjustable centrifugal pump

Abstract

The application relates to the technical field of centrifugal pumps, in particular to a pressure-adjustable centrifugal pump which comprises a motor and a pump base, the inside of the pump base is hollow, the bottom of the pump base is open, a bottom shell is arranged at the open end of the bottom of the pump base, a main shaft is coaxially arranged on the output shaft of the motor, the main shaft penetrates into the pump base and rotates, a plurality of booster pipes are coaxially arranged on the main shaft between the pump base and the bottom shell, a partition ring is coaxially arranged in the booster pipe, a booster chamber is formed between two adjacent partition rings, an impeller is rotationally arranged in the booster chamber, the impeller rotates coaxially and is sleeved on the main shaft, a spacing ring is coaxially arranged on the main shaft between two adjacent impellers, a plurality of shaft pins are slidingly arranged on the main shaft, the shaft pins are in one-to-one correspondence with the impellers, a linkage groove for inserting the shaft pins is formed in the impeller, and a linkage assembly for driving the plurality of shaft pins to sequentially slide and separate from the linkage groove is arranged on the pump base. The application has the effect of prolonging the service life of the centrifugal pump.

Description

Technical Field

[0001] This application relates to the field of centrifugal pump technology, and in particular to a pressure-adjustable centrifugal pump. Background Technology

[0002] A centrifugal pump is a mechanical device that converts mechanical energy into liquid kinetic or potential energy for conveying or pressurizing liquids. Centrifugal pumps utilize the centrifugal force generated by the high-speed rotating impeller to throw liquid out of the impeller, forming a low-pressure zone and drawing in new liquid, thereby achieving continuous conveying.

[0003] Currently, when it is necessary to change the pressure of the liquid being pumped during the operation of some centrifugal pumps, a frequency converter is usually used to change the speed of the motor output shaft, thereby changing the pressure of the liquid being pumped. However, the following problems may occur when changing the speed of the motor output shaft using a frequency converter for a long time: 1. When the motor output shaft rotates at high speed, the frequency converter will generate high-frequency harmonics. The electromagnetic force of high-frequency harmonics can easily cause bearing lubrication failure, generate electrical spark corrosion (washboard pattern), and aggravate the resonance of the motor structure, resulting in noise and vibration. At the same time, high-frequency voltage spikes (up to twice the rated voltage) and shaft voltage (exceeding the insulation capacity of bearing grease) will damage the insulation effect of the coil ends and bearings, which will greatly shorten the service life of the centrifugal pump. 2. When the motor output shaft rotates at low speed, the cubic volume of the motor's self-cooling ventilation decreases, and the motor's self-cooling effect deteriorates sharply, which significantly increases the risk of motor overheating and greatly shortens the service life of the centrifugal pump, thus presenting a drawback. Summary of the Invention

[0004] To address the problems caused by altering the motor output shaft of a centrifugal pump via a frequency converter, this application provides a pressure-adjustable centrifugal pump.

[0005] The pressure-adjustable centrifugal pump provided in this application adopts the following technical solution: An adjustable pressure centrifugal pump includes a motor and a pump base. The pump base is hollow inside and open at the bottom. A water outlet pipe is connected to the top of the pump base. A bottom shell is provided at the open bottom end of the pump base. Several filter holes are formed between the inner and outer walls of the bottom shell. A main shaft is coaxially arranged on the output shaft of the motor. The main shaft rotatably passes through the pump base. The end of the main shaft facing away from the motor is rotatably arranged on the bottom shell. Multiple pressure boosting pipes are coaxially sleeved on the main shaft between the pump base and the bottom shell. The multiple pressure boosting pipes are evenly arranged along the axial direction of the main shaft. A spacer ring is coaxially arranged inside the pipe. There is a gap between the inner diameter sidewall of the spacer ring and the outer diameter sidewall of the main shaft. A pressurization chamber is formed between two adjacent spacer rings. An impeller is rotatably arranged in the pressurization chamber. The impeller rotates coaxially and is sleeved on the main shaft. A spacer ring is coaxially sleeved on the main shaft between two adjacent impellers. Multiple shaft pins are slidably arranged on the main shaft. Each shaft pin corresponds to one of the impellers. A linkage groove is opened on the impeller for the shaft pins to be inserted. A linkage assembly is provided on the pump base for driving the multiple shaft pins to slide out of the linkage groove in sequence.

[0006] By adopting the above technical solution, when it is necessary to reduce the pressure of the liquid being pumped, the linkage component causes the shaft pins corresponding to some impellers to disengage sequentially from the linkage grooves on the impellers. This causes the linkage between these impellers and the main shaft to be lost. In other words, the impellers that are no longer linked cannot pressurize the liquid, but can only allow the liquid to flow. Therefore, the pressure of the pumped liquid will decrease. Similarly, the pressure of the pumped liquid can be increased. However, during the increase and decrease of the pumped liquid pressure, the speed of the motor driving the main shaft will not change. This solves the problem caused by the excessively high and low speed of the motor output shaft due to traditional frequency converters, and helps to extend the service life of the motor.

[0007] Optionally, a support bar is provided on the partition ring, and a flow-encircling ring plate coaxial with the partition ring is provided on the support bar. The flow-encircling ring plate is coaxially sleeved on the main shaft and is located between the spacing ring and the impeller. There is a gap between the outer circumferential wall of the flow-encircling ring plate and the inner circumferential wall of the booster tube. A section tube is provided between two adjacent booster tubes. A middle plate ring is coaxially provided on the inner wall of the section tube. The middle plate ring is located between the flow-encircling ring plate and the impeller and is attached to the side of the impeller facing away from the motor.

[0008] By adopting the above technical solution, the centrifuged liquid at the impeller edge flows back into the inlet end of the next stage impeller through the flow channel between the flow ring plate and the partition ring, thereby achieving the effect of step-by-step pressurization. The flow ring plate and the middle plate ring make it easier for the rotating impeller to form a pressurized environment, which is beneficial to improving the pressurization effect on the liquid.

[0009] Optionally, the linkage assembly includes a torque shaft slidably arranged between the motor output shaft and the main shaft. A sliding member is provided on the pump base to drive the torque shaft to slide. A polygonal sliding column is provided at the top of the torque shaft. A torque tube is coaxially arranged on the motor output shaft. The torque tube is slidably sleeved on the sliding column. The outer circumferential wall of the sliding column is attached to the inner circumferential wall of the torque tube. A drive rod is slidably arranged along the axial direction of the main shaft. A drive groove is provided on the main shaft for the drive rod to slide. Both the drive rod and the drive groove have polygonal cross-sections. The drive rod is arranged at the bottom of the torque shaft. An end-sealing plate is coaxially arranged at the top of the main shaft. The torque shaft slides through the end-sealing plate. A drive pin member is provided on the drive rod to drive multiple shaft pins to slide sequentially.

[0010] By adopting the above technical solution, during the sliding process of the sliding member driving the torque shaft, the torque on the output shaft of the motor is transmitted to the main shaft through the torque tube, sliding shaft column, torque shaft and drive rod. This allows the main shaft to maintain synchronous rotation with the output shaft of the motor during the sliding process of the drive rod. During the sliding process of the drive rod, the drive pin can drive the shaft pin to slide in sequence, thereby realizing the linkage and disconnection between the main shaft and the impeller. This achieves the effect of changing the pressure of the conveyed liquid without changing the speed of the motor output shaft.

[0011] Optionally, the sliding member includes a torque ring plate coaxially disposed on the torque shaft, an electric cylinder electrically connected to the control system is disposed on the pump base, a C-shaped locking block is disposed on the piston rod of the electric cylinder, and the edge of the torque ring plate is located on the concave side of the C-shaped locking block.

[0012] By adopting the above technical solution, the control system starts the electric cylinder. The output shaft of the electric cylinder drives the torque ring plate to slide synchronously through the locking block. During the process of the torque ring plate driving the torque shaft to slide synchronously, the torque shaft and the torque ring plate can maintain the effect of synchronous rotation, and the electric cylinder can achieve the effect of precise control of the torque shaft sliding distance.

[0013] Optionally, the drive pin includes multiple engagement and disengagement slots formed on the drive rod, each slot corresponding to a shaft pin. A mounting block is detachably mounted on the main shaft, and a guide post is provided on the mounting block. A pin groove is formed on the shaft pin, and the guide post is inserted into the pin groove of the shaft pin. A compression spring supports the mounting block and the shaft pin. A drive pin block is provided on the shaft pin, and a drive inclined surface is formed on the drive pin block. The drive inclined surface is inclined away from the mounting block along the direction from the torque ring plate to the main shaft. The drive rod... A stop bar is provided in the engagement groove. The stop bar is located on the side of the drive pin block facing away from the mounting block. The stop bar is used to prevent the drive pin block from disengaging from the engagement groove. A grading rod is provided on the stop bar along the axis of the main shaft. The length of the multiple grading rods along the torque ring plate to the main shaft gradually decreases. The end of the grading rod near the drive pin block is used to abut against and slide against the drive inclined surface. The width of the grading rod along the axis of the shaft pin is less than the distance between the drive pin block and the mounting block.

[0014] By adopting the above technical solution, when it is necessary to reduce the pressure of the conveyed liquid, the piston rod of the electric cylinder will retract, and the torque shaft will drive the drive rod to slide along the direction away from the torque ring plate. During this process, the classifying rod in the dividing groove closest to the torque shaft on the drive rod will first approach and abut against the drive pin block corresponding to the classifying rod. As the drive rod continues to slide, the end of the classifying rod will abut against the drive inclined surface of the drive pin block and slide relative to the drive inclined surface. Under the action of the drive inclined surface, the drive pin block will gradually move away from the stop bar until the drive pin block abuts against the side of the classifying rod near the mounting block. At this time, the shaft pin separates from the linkage groove on the impeller. During this process, the compression spring is continuously compressed. As the drive rod continues to slide, the shaft pin corresponding to this impeller will not continue to slide until the bottom end of another adjacent classifying rod along the sliding direction of the drive rod abuts against the drive inclined surface on the drive pin block corresponding to the classifying rod again. This achieves the effect of linkage and disconnection between the impeller and the main shaft, thereby achieving the effect of changing the pressure of the conveyed liquid without changing the motor speed.

[0015] Optionally, a sealing ring is provided between each of the two adjacent booster pipes.

[0016] By adopting the above technical solution, it is beneficial to improve the sealing performance between two adjacent booster pipes.

[0017] Optionally, a fixing strip is detachably provided on the pump base, and a hook is provided at one end of the fixing strip near the bottom shell. A hook groove is provided on the bottom shell for the hook to be hooked into.

[0018] By adopting the above technical solution, workers can quickly assemble and fix multiple booster pipes by hooking the hook end of the fixing strip into the hook groove on the bottom shell and fixing the other end to the pump base.

[0019] Optionally, a sealing ring is provided between the end sealing plate and the torque shaft.

[0020] By adopting the above technical solution, it is beneficial to reduce the possibility of liquid leakage between the end sealing plate and the torque shaft.

[0021] In summary, this application includes at least one of the following beneficial technical effects: 1. When it is necessary to reduce the pressure of the liquid being pumped, the linkage component causes the shaft pins corresponding to some impellers to disengage from the linkage grooves on the impellers in sequence. This causes the linkage between these impellers and the main shaft to be lost. In other words, the impellers that are no longer linked cannot pressurize the liquid, but can only allow the liquid to flow. Therefore, the pressure of the pumped liquid will decrease. Similarly, the pressure of the pumped liquid can be increased. However, during the increase and decrease of the pumped liquid pressure, the speed of the motor driving the main shaft will not change. This solves the problem caused by the excessively high or low speed of the motor output shaft caused by traditional frequency converters, and helps to extend the service life of the motor. 2. During the sliding process of the sliding component driving the torque shaft, the torque on the motor output shaft is transmitted to the main shaft through the torque tube, sliding shaft column, torque shaft and drive rod. This allows the main shaft to maintain synchronous rotation with the motor output shaft during the sliding process of the drive rod. During the sliding process of the drive rod, the drive pin component can drive the shaft pin to slide in sequence, thereby realizing the linkage and disconnection between the main shaft and the impeller. This achieves the effect of changing the pressure of the conveyed liquid without changing the speed of the motor output shaft. 3. When it is necessary to reduce the pressure of the conveyed liquid, the piston rod of the electric cylinder will retract, and the torque shaft will drive the drive rod to slide along the direction away from the torque ring plate. During this process, the classifying rod in the dividing groove closest to the torque shaft on the drive rod will first approach and abut against the drive pin block corresponding to the classifying rod. As the drive rod continues to slide, the end of the classifying rod will abut against the drive inclined surface of the drive pin block and slide relative to the drive inclined surface. Under the action of the drive inclined surface, the drive pin block will gradually move away from the stop bar until the drive pin block abuts against the side of the classifying rod near the mounting block. At this time, the shaft pin separates from the linkage groove on the impeller. During this process, the compression spring is continuously compressed. As the drive rod continues to slide, the shaft pin corresponding to this impeller will not continue to slide until the bottom end of another adjacent classifying rod along the sliding direction of the drive rod abuts against the drive inclined surface on the drive pin block corresponding to the classifying rod again. This achieves the effect of linkage and disconnection between the impeller and the main shaft, thereby achieving the effect of changing the pressure of the conveyed liquid without changing the motor speed. Attached Figure Description

[0022] Figure 1 This is a structural schematic diagram of an embodiment of this application.

[0023] Figure 2 This is a cross-sectional view used in the embodiments of this application to illustrate the positional relationship between the impeller, the booster tube, and the main shaft.

[0024] Figure 3 yes Figure 2 Enlarged view of section A.

[0025] Figure 4 yes Figure 2 Enlarged view of section B.

[0026] Explanation of reference numerals in the attached drawings: 1. Motor; 2. Pump base; 3. Outlet pipe; 4. Bottom shell; 5. Filter hole; 6. Main shaft; 7. Booster pipe; 8. Spacer ring; 9. Booster chamber; 10. Impeller; 11. Spacing ring; 12. Shaft pin; 13. Linkage groove; 14. Linkage assembly; 141. Torque shaft; 142. Sliding component; 1421. Torque ring plate; 1422. Electric cylinder; 1423. Clamping block; 143. Sliding shaft column; 144. Torque tube; 145. Drive rod; 146. 147. Drive slot; 15. End sealing plate; 16. Support bar; 17. Flow ring plate; 18. Section pipe; 19. Middle plate ring; 10. Drive pin; 191. Dividing and distributing slot; 192. Mounting block; 193. Guide column; 194. Pin groove; 195. Compression spring; 196. Drive pin block; 197. Drive inclined surface; 198. Stop bar; 199. Grader rod; 20. Sealing ring; 21. Fixing strip; 22. Hook; 23. Hook groove; 24. Sealing ring; 25. Base. Detailed Implementation

[0027] The following is in conjunction with the appendix Figures 1-4 This application will be described in further detail.

[0028] This application discloses a pressure-adjustable centrifugal pump.

[0029] Reference Figure 1 An adjustable pressure centrifugal pump includes a motor 1 and a pump base 2. A base 25 is bolted between the motor 1 and the pump base 2. The motor 1 is bolted to the top of the base 25, and the pump base 2 is bolted to the bottom of the base 25. The pump base 2 is hollow inside and open at the bottom. A water outlet pipe 3 is connected to the top of the pump base 2. A bottom shell 4 is arranged at the open end of the bottom of the pump base 2. Several filter holes 5 are opened between the inner and outer walls of the bottom shell 4.

[0030] Reference Figure 2A main shaft 6 is coaxially arranged on the output shaft of motor 1. The main shaft 6 rotates through the pump base 2. The end of the main shaft 6 facing away from motor 1 is rotated and arranged on the bottom shell 4. Multiple booster pipes 7 are coaxially sleeved on the main shaft 6 between pump base 2 and bottom shell 4. The multiple booster pipes 7 are evenly arranged along the axial direction of the main shaft 6.

[0031] Reference Figure 1 and Figure 2 A sealing ring 20 is arranged between each of the two adjacent booster pipes 7. The sealing ring 20 can be made of rubber material in the existing technology. A fixing strip 21 is bolted to the pump base 2. A hook 22 is integrally formed at one end of the fixing strip 21 near the bottom shell 4. A hook groove 23 is opened on the bottom shell 4 for the hook 22 to be hooked into.

[0032] Reference Figure 2 A spacer ring 8 is integrally formed and coaxially arranged inside the booster pipe 7. There is a gap between the inner diameter sidewall of the spacer ring 8 and the outer diameter sidewall of the main shaft 6. A booster chamber 9 is formed between the spacer rings 8 on two adjacent booster pipes 7. An impeller 10 is rotatably arranged inside the booster chamber 9. The impeller 10 rotates coaxially and is sleeved on the main shaft 6. A spacer ring 11 is coaxially sleeved on the main shaft 6 between two adjacent impellers 10.

[0033] Reference Figure 2 and Figure 3 A support bar 15 is welded on the partition ring 8, and a flow ring plate 16 coaxial with the partition ring 8 is welded on the support bar 15. The flow ring plate 16 is coaxially sleeved on the main shaft 6. The flow ring plate 16 is located between the spacing ring 11 and the impeller 10. There is a gap between the outer circumferential wall of the flow ring plate 16 and the inner circumferential wall of the booster pipe 7.

[0034] Reference Figure 2 , Figure 3 and Figure 4 A section pipe 17 is arranged between two adjacent booster pipes 7. The section pipe 17 is coaxially inserted into the booster pipe 7. The outer circumferential wall of the section pipe 17 is attached to the inner circumferential wall of the booster pipe 7. A middle plate ring 18 is coaxially and integrally formed on the inner wall of the section pipe 17. The middle plate ring 18 is located between the flow ring plate 16 and the impeller 10. The middle plate ring 18 is attached to the side of the impeller 10 facing away from the motor 1.

[0035] When the output shaft of motor 1 drives the main shaft 6 to rotate, the main shaft 6 drives multiple impellers 10 to rotate synchronously. External liquid flows into the bottom inlet of impeller 10 through filter hole 5. The impeller 10 rotating below squeezes the liquid into the pressurization chamber 9 through centrifugal force. The liquid flows along the liquid flow formed by the flow ring plate 16, the partition ring 8 and the middle plate ring 18 in the pressurization chamber 9 to the bottom inlet of the impeller 10 located at the top. This process is repeated, and the liquid is continuously pressurized and finally discharged quickly from the outlet pipe 3 at the top of the pump base 2.

[0036] Reference Figure 2 and Figure 4 Multiple shaft pins 12 are slidably arranged on the main shaft 6. Each shaft pin 12 corresponds to an impeller 10. The impeller 10 is provided with a linkage groove 13 for the shaft pins 12 to be inserted. The pump base 2 is provided with a linkage assembly 14 for driving the multiple shaft pins 12 to slide out of the linkage groove 13 in sequence.

[0037] Reference Figure 2 and Figure 4 The linkage assembly 14 includes a torque shaft 141 slidably arranged between the output shaft of the motor 1 and the main shaft 6. A sliding member 142 is arranged on the pump base 2 to drive the torque shaft 141 to slide. The sliding member 142 includes a torque ring plate 1421 coaxially welded to the torque shaft 141. An electric cylinder 1422 electrically connected to the control system is bolted to the pump base 2. A C-shaped locking block 1423 is bolted to the piston rod of the electric cylinder 1422. The edge of the torque ring plate 1421 is located on the C-shaped concave side of the locking block 1423.

[0038] Reference Figure 2 and Figure 4 The top of the torque shaft 141 is welded with a sliding shaft column 143 with a regular hexagonal cross section. A torque tube 144 is coaxially bolted to the output shaft of the motor 1. The torque tube 144 is slidably sleeved on the sliding shaft column 143. The outer circumferential wall of the sliding shaft column 143 is attached to the inner circumferential wall of the torque tube 144. A drive rod 145 is slidably arranged in the axial direction of the main shaft 6. The drive rod 145 is welded and assembled from multiple parts.

[0039] Reference Figure 2 , Figure 3 and Figure 4 The main shaft 6 has a drive groove 146 for the drive rod 145 to slide. The cross-section of both the drive rod 145 and the drive groove 146 is polygonal. The drive rod 145 is welded to the bottom of the torque shaft 141. An end sealing plate 147 is coaxially welded to the top of the main shaft 6. A sealing ring 24 is arranged between the end sealing plate 147 and the torque shaft 141. The torque shaft 141 slides through the end sealing plate 147. The drive rod 145 is provided with drive pin parts 19 for driving multiple shaft pins 12 to slide sequentially.

[0040] Reference Figure 2 and Figure 3 The drive pin 19 includes multiple engagement and disengagement slots 191 formed on the drive rod 145, each corresponding to a shaft pin 12. A mounting block 192 is bolted to the main shaft 6, and a guide post 193 is welded to the mounting block 192. A pin groove 194 is coaxially formed on the shaft pin 12, and the guide post 193 is inserted into the pin groove 194 of the shaft pin 12. A compression spring 195 supports the mounting block 192 and the shaft pin 12. A drive pin block 196 is welded to the shaft pin 12, and a drive inclined surface 197 is formed on the drive pin block 196.

[0041] Reference Figure 2 and Figure 3 The drive ramp 197 is inclined away from the mounting block 192 along the direction from the torque ring plate 1421 to the main shaft 6. The length of the projection line of the drive ramp 197 in the direction of the shaft pin 12 axis is longer than the length of the linkage groove 13. A stop bar 198 is welded in the split groove 191 of the drive rod 145. The stop bar 198 is located on the side of the drive pin block 196 away from the mounting block 192. The stop bar 198 is used to prevent the drive pin block 196 from disengaging from the split groove 191.

[0042] Reference Figure 2 and Figure 3 A grading rod 199 is welded on the stop bar 198 along the axial direction of the main shaft 6. The length of multiple grading rods 199 along the direction from the torque ring plate 1421 to the main shaft 6 gradually decreases. The length difference between two adjacent grading rods 199 is the same. The end of the grading rod 199 near the drive pin block 196 is used to abut against and slide with the drive inclined surface 197. The width of the grading rod 199 along the axial direction of the shaft pin 12 is less than the distance between the drive pin block 196 and the mounting block 192.

[0043] When it is necessary to reduce the pressure of the conveyed liquid, the control system activates the electric cylinder 1422. The piston rod of the electric cylinder 1422 retracts, and the piston rod of the electric cylinder 1422 drives the locking block 1423 to descend a certain distance. The locking block 1423 drives the torque shaft 141 to descend synchronously through the torque ring plate 1421. The top of the torque shaft 141 will drive the sliding column 143 to slide relative to the torque tube 144. At the same time, the main shaft 6 can still rotate synchronously with the output shaft of the motor 1. The bottom of the torque shaft 141 will push the drive rod 145 to descend synchronously a certain distance.

[0044] During this process, the grading rod 199 located in the uppermost split groove 191 on the drive rod 145 will first approach and abut against the drive pin block 196 corresponding to the grading rod 199. As the drive rod 145 continues to slide, the bottom end of the grading rod 199 will abut against the drive ramp 197 on the drive pin block 196 until the bottom end of the grading rod 199 and the drive ramp 197 slide relative to each other. Under the action of the drive ramp 197, the drive pin block 196 will gradually move away from the stop bar 198.

[0045] Until the drive pin block 196 abuts against the side of the grader rod 199 near the mounting block 192, the shaft pin 12 separates from the linkage groove 13 on the impeller 10. At the same time, during this process, the compression spring 195 at the top will be continuously compressed. As the drive rod 145 continues to slide, the shaft pin 12 corresponding to the impeller 10 at the top will not continue to slide.

[0046] Until the bottom end of the first classifying rod 199 located below the uppermost impeller 10 abuts against the driving inclined surface 197 on the drive pin block 196 corresponding to the classifying rod 199 again, as the drive rod 145 continues to slide, the shaft pin 12 on the second impeller 10 will also gradually separate from the linkage groove 13 on the impeller 10. This process is repeated until the drive rod 145 stops sliding.

[0047] During this process, some impellers 10 will lose their linkage with the main shaft 6. That is, the main shaft 6 cannot drive the impellers 10 that have lost their linkage to rotate synchronously, and these impellers 10 cannot pressurize the liquid; they can only achieve the effect of liquid flow.

[0048] Therefore, the pressure of the liquid being transported will decrease, but the rotational speed of the motor 1 driving the spindle 6 will not change, thus solving the problem caused by the excessively high or low output shaft speed of the motor 1 caused by traditional frequency converters.

[0049] The implementation principle of a pressure-adjustable centrifugal pump according to an embodiment of this application is as follows: When the output shaft of the motor 1 drives the main shaft 6 to rotate, the main shaft 6 drives multiple impellers 10 to rotate synchronously. The external liquid flows into the bottom water inlet of the impeller 10 through the filter hole 5. The impeller 10 rotating below squeezes the liquid into the pressurization chamber 9 through centrifugal force. The liquid flows along the liquid flow formed by the flow ring plate 16, the partition ring 8 and the middle plate ring 18 in the pressurization chamber 9 to the bottom water inlet of the impeller 10 located at the top. This process is repeated, and the liquid is continuously pressurized and finally discharged quickly from the outlet pipe 3 at the top of the pump base 2.

[0050] When it is necessary to reduce the pressure of the conveyed liquid, the control system activates the electric cylinder 1422. The piston rod of the electric cylinder 1422 retracts, and the piston rod of the electric cylinder 1422 drives the locking block 1423 to descend a certain distance. The locking block 1423 drives the torque shaft 141 to descend synchronously through the torque ring plate 1421. The top of the torque shaft 141 will drive the sliding column 143 to slide relative to the torque tube 144. At the same time, the main shaft 6 can still rotate synchronously with the output shaft of the motor 1. The bottom of the torque shaft 141 will push the drive rod 145 to descend synchronously a certain distance.

[0051] During this process, the grading rod 199 located in the uppermost split groove 191 on the drive rod 145 will first approach and abut against the drive pin block 196 corresponding to the grading rod 199. As the drive rod 145 continues to slide, the bottom end of the grading rod 199 will abut against the drive ramp 197 on the drive pin block 196 until the bottom end of the grading rod 199 and the drive ramp 197 slide relative to each other. Under the action of the drive ramp 197, the drive pin block 196 will gradually move away from the stop bar 198.

[0052] Until the drive pin block 196 abuts against the side of the grader rod 199 near the mounting block 192, the shaft pin 12 separates from the linkage groove 13 on the impeller 10. At the same time, during this process, the compression spring 195 at the top will be continuously compressed. As the drive rod 145 continues to slide, the shaft pin 12 corresponding to the impeller 10 at the top will not continue to slide.

[0053] Until the bottom end of the first classifying rod 199 located below the uppermost impeller 10 abuts against the driving inclined surface 197 on the drive pin block 196 corresponding to the classifying rod 199 again, as the drive rod 145 continues to slide, the shaft pin 12 on the second impeller 10 will also gradually separate from the linkage groove 13 on the impeller 10. This process is repeated until the drive rod 145 stops sliding.

[0054] During this process, some impellers 10 will lose their linkage with the main shaft 6. That is, the main shaft 6 cannot drive the impellers 10 that have lost their linkage to rotate synchronously, and these impellers 10 cannot pressurize the liquid; they can only achieve the effect of liquid flow.

[0055] Therefore, the pressure of the liquid being transported will decrease, but the rotational speed of the motor 1 driving the spindle 6 will not change, thus solving the problem caused by the excessively high or low output shaft speed of the motor 1 caused by traditional frequency converters.

[0056] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A pressure-adjustable centrifugal pump, characterized in that: The system includes a motor (1) and a pump base (2). The pump base (2) is hollow inside and open at the bottom. A water outlet pipe (3) is connected to the top of the pump base (2). A bottom shell (4) is provided at the open bottom end of the pump base (2). Several filter holes (5) are provided between the inner and outer walls of the bottom shell (4). A main shaft (6) is coaxially arranged on the output shaft of the motor (1). The main shaft (6) rotates through the pump base (2). The end of the main shaft (6) facing away from the motor (1) is rotatably arranged on the bottom shell (4). Multiple booster pipes (7) are coaxially sleeved on the main shaft (6) between the pump base (2) and the bottom shell (4). The multiple booster pipes (7) are evenly arranged along the axial direction of the main shaft (6). A spacer ring (8) is coaxially provided inside the booster pipe (7). There is a gap between the inner diameter sidewall of the partition ring (8) and the outer diameter sidewall of the main shaft (6). A pressurization chamber (9) is formed between two adjacent partition rings (8). An impeller (10) is rotatably arranged in the pressurization chamber (9). The impeller (10) rotates coaxially and is sleeved on the main shaft (6). A spacing ring (11) is coaxially sleeved on the main shaft (6) between two adjacent impellers (10). A plurality of shaft pins (12) are slidably arranged on the main shaft (6). The shaft pins (12) correspond one-to-one with the impellers (10). A linkage groove (13) is opened on the impeller (10) for the shaft pins (12) to be inserted. A linkage assembly (14) is provided on the pump base (2) for driving the plurality of shaft pins (12) to slide out of the linkage groove (13) in sequence.

2. The pressure-adjustable centrifugal pump according to claim 1, characterized in that: A support bar (15) is provided on the partition ring (8), and a flow ring plate (16) coaxial with the partition ring (8) is provided on the support bar (15). The flow ring plate (16) is coaxially sleeved on the main shaft (6). The flow ring plate (16) is located between the spacing ring (11) and the impeller (10). There is a gap between the outer circumferential wall of the flow ring plate (16) and the inner circumferential wall of the booster pipe (7). A section pipe (17) is provided between two adjacent booster pipes (7). A middle plate ring (18) is coaxially provided on the inner wall of the section pipe (17). The middle plate ring (18) is located between the flow ring plate (16) and the impeller (10). The middle plate ring (18) is attached to the side of the impeller (10) facing away from the motor (1).

3. The pressure-adjustable centrifugal pump according to claim 2, characterized in that: The linkage assembly (14) includes a torque shaft (141) slidably arranged between the output shaft of the motor (1) and the main shaft (6). A sliding member (142) for driving the torque shaft (141) to slide is provided on the pump base (2). A polygonal sliding column (143) is provided at the top of the torque shaft (141). A torque tube (144) is coaxially arranged on the output shaft of the motor (1). The torque tube (144) is slidably sleeved on the sliding column (143). The outer circumferential wall of the sliding column (143) is attached to the inner circumferential wall of the torque tube (144). A drive rod (145) is slidably arranged on the axis of the main shaft (6). A drive groove (146) is provided on the main shaft (6) for the drive rod (145) to slide. The cross-section of the drive rod (145) and the drive groove (146) are both polygonal. The drive rod (145) is arranged at the bottom of the torque shaft (141). An end sealing plate (147) is coaxially arranged on the top of the main shaft (6). The torque shaft (141) slides through the end sealing plate (147). The drive rod (145) is provided with drive pins (19) for driving multiple shaft pins (12) to slide sequentially.

4. The pressure-adjustable centrifugal pump according to claim 3, characterized in that: The sliding member (142) includes a torque ring plate (1421) coaxially disposed on the torque shaft (141), and an electric cylinder (1422) electrically connected to the control system is disposed on the pump base (2). A C-shaped locking block (1423) is disposed on the piston rod of the electric cylinder (1422), and the edge of the torque ring plate (1421) is located on the C-shaped concave side of the locking block (1423).

5. A pressure-adjustable centrifugal pump according to claim 4, characterized in that: The drive pin component (19) includes a plurality of engagement and disengagement grooves (191) formed on the drive rod (145), each engagement and disengagement groove (191) corresponding to a shaft pin (12). A mounting block (192) is detachably mounted on the main shaft (6). A guide post (193) is provided on the mounting block (192). A pin groove (194) is formed on the shaft pin (12), and the guide post (193) is inserted into the pin groove (194) of the shaft pin (12). A compression spring (195) supports the mounting block (192) and the shaft pin (12). A drive pin block (196) is provided on the shaft pin (12), and a drive inclined surface (197) is formed on the drive pin block (196). The drive inclined surface (197) is inclined away from the mounting block (192) along the direction from the torque ring plate (1421) to the main shaft (6). A stop bar (198) is provided in the engagement groove (191) of the drive rod (145). The stop bar (198) is located on the side of the drive pin block (196) facing away from the mounting block (192). The stop bar (198) is used to prevent the drive pin block (196) from disengaging from the engagement groove (191). A grader bar (199) is provided on the stop bar (198) along the axial direction of the main shaft (6). The length of the multiple grader bars (199) along the direction from the torque ring plate (1421) to the main shaft (6) gradually decreases. The end of the grader bar (199) near the drive pin block (196) is used to abut against and slide against the drive inclined surface (197). The width of the grader bar (199) along the axial direction of the shaft pin (12) is less than the distance between the drive pin block (196) and the mounting block (192).

6. A pressure-adjustable centrifugal pump according to claim 1, characterized in that: A sealing ring (20) is provided between each of the two adjacent booster pipes (7).

7. A pressure-adjustable centrifugal pump according to claim 1, characterized in that: A fixing strip (21) is detachably provided on the pump base (2). A hook (22) is provided at one end of the fixing strip (21) near the bottom shell (4). A hook groove (23) is provided on the bottom shell (4) for the hook (22) to be hooked into.

8. A pressure-adjustable centrifugal pump according to claim 3, characterized in that: A sealing ring (24) is provided between the end sealing plate (147) and the torque shaft (141).

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