Water-cooling quiet vertical multi-stage pump of permanent magnet motor

Abstract

This invention relates to the field of multistage pump technology and discloses a water-cooled, quiet vertical multistage pump with a permanent magnet motor. The pump includes a base and an inner and outer cylinder fixed to the base. A pump shaft is rotatably connected to the base. A drive assembly for driving the pump shaft is located at the top of the inner cylinder. Multiple conical rings are fixedly installed inside the inner cylinder. Impellers corresponding to the conical rings are coaxially fixed to the outer side of the pump shaft. A mechanical seal assembly is provided between the inner hole of each conical ring and the outer wall of the impeller. A monitoring assembly is provided on each conical ring. During liquid transportation, this invention monitors the interstage pressure difference in real time through the monitoring assembly. When interstage leakage causes the pressure difference to drop to a set threshold, the pump shaft accelerates automatically through circuit switching, maintaining the set flow rate at the pump outlet and ensuring the operating efficiency and stability of the pump transportation system.

Description

Technical Field

[0001] This invention relates to the field of multistage pump technology, specifically to a water-cooled, quiet vertical multistage pump powered by a permanent magnet motor. Background Technology

[0002] The water-cooled, silent vertical multistage pump with a permanent magnet motor is a high-efficiency fluid transport device that combines direct-drive technology of a permanent magnet synchronous motor with the structure of a vertical multistage centrifugal pump. It utilizes the magnetic coupling of the permanent magnet motor to achieve non-contact torque transmission, allowing the power components to be surrounded by water during operation. This enables effective heat dissipation of the motor through a water-cooling system, and the water layer shields noise, achieving quiet operation. This pump type has wide applications in ships, airports, high-rise building water supply, industrial cleaning, chemical processes, boiler feedwater, water treatment, and precision cooling systems, and is particularly suitable for applications with high requirements for space, noise, and operational stability.

[0003] During pump operation, each impeller stage is equipped with a mechanical seal structure between itself and the pump casing. This seal typically consists of a rotating ring fixed to the impeller and a stationary ring fixed to the pump casing. These precisely fitted end faces form a relatively sliding sealing surface during pump operation. Their main function is to effectively isolate adjacent high-pressure and low-pressure areas within the pump, greatly reducing internal leakage between stages. This plays a crucial role in maintaining the pressure gradient between stages and ensuring stable pump operation.

[0004] However, during long-term high-speed relative operation, the dynamic and static rings of a mechanical seal will inevitably wear due to factors such as media characteristics, installation accuracy, and material fatigue. As the wear gradually accumulates, the sealing gap gradually increases, which will lead to a significant increase in interstage leakage. The increased leakage will disrupt the original pressure balance, resulting in a decrease in interstage pressure difference. When this performance degradation is transmitted to the pump outlet, it will ultimately manifest as a reduction in the pump's delivery flow rate and head, thereby seriously affecting the operating efficiency and stability of the entire pump delivery system. Summary of the Invention

[0005] The purpose of this invention is to provide a water-cooled, quiet, vertical multistage pump with a permanent magnet motor to solve the problems mentioned above.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A water-cooled, quiet, vertical multistage pump with a permanent magnet motor includes a base and an inner cylinder and an outer cylinder fixed on the base. A pump shaft is rotatably connected to the base. A drive assembly for driving the pump shaft is provided at the top of the inner cylinder. Multiple conical rings are fixedly installed on the inner side of the inner cylinder. Impellers corresponding to the conical rings are coaxially fixed on the outer side of the pump shaft. A mechanical seal assembly is provided between the inner hole of each set of conical rings and the outer wall of the impeller. A monitoring assembly is provided on each conical ring. The monitoring component includes a mounting base that passes through a conical ring and a slide that is slidably connected to the mounting base. The mounting base has a through hole, and a piston is slidably connected to the through hole. The displacement of the piston drives the slide to slide, and a conductive slide is fixedly mounted on the slide. The monitoring component further includes a first branch, a second branch, and a third branch. The total resistance of the second branch is greater than that of the first branch. The conductive slide block slides so that one end of it is electrically connected to one end of the first branch and one end of the second branch, respectively, and the other end of the conductive slide block is electrically connected to the third branch. The other ends of the first and second branches are electrically connected and then connected in series with the third branch in the circuit of the drive component.

[0007] As a preferred embodiment of the water-cooled, silent vertical multistage pump of the permanent magnet motor described in this invention, the second branch is connected in series with a resistor and an indicator light, and the first and third branches are both composed of wires.

[0008] As a preferred embodiment of the water-cooled, noise-reducing vertical multistage pump of the permanent magnet motor described in this invention, a fixing ring is fixedly installed in the through hole, a spring is fixedly connected between the fixing ring and the piston, and a first push rod and a second push rod with their ends extending into the through hole are fixedly installed at the upper and lower ends of the slide respectively, with the first push rod and the second push rod located on the upper and lower sides of the piston respectively.

[0009] As a preferred embodiment of the water-cooled, silent vertical multistage pump for the permanent magnet motor described in this invention, a flow channel is provided between the inner cylinder and the outer cylinder, a flow port is provided at the top of the inner cylinder, and an inlet pipe and an outlet pipe are fixed on the base. The inlet pipe is connected to the interior of the inner cylinder, and the outlet pipe is connected to the flow channel.

[0010] As a preferred embodiment of the water-cooled, quiet vertical multistage pump for the permanent magnet motor described in this invention, a controller is fixedly installed on the top of the outer cylinder.

[0011] As a preferred embodiment of the water-cooled, quiet vertical multistage pump for the permanent magnet motor described in this invention, wherein: a conical top ring is fixed inside the inner cylinder, and multiple guide vanes are rotatably connected above each impeller on the outside of the pump shaft, with the uppermost guide vane fixedly connected below the conical top ring, and the remaining guide vanes respectively fixedly connected to the conical ring above them.

[0012] As a preferred embodiment of the water-cooled, quiet vertical multistage pump of the permanent magnet motor described in this invention, the drive assembly includes an excitation winding fixed in the outer cylinder and an inner magnetic frame fixedly connected coaxially with the pump shaft. Multiple permanent magnets are fixed in a circumferential array within the inner magnetic frame. An isolation sleeve is provided between the inner magnetic frame and the excitation winding, and the isolation sleeve is fixedly connected between the top of the inner cylinder and the outer cylinder.

[0013] As a preferred embodiment of the water-cooled, quiet vertical multistage pump of the permanent magnet motor described in this invention, a support frame is fixedly installed inside the inner cylinder, and the pump shaft is rotatably connected to the support frame.

[0014] As a preferred embodiment of the water-cooled, quiet vertical multistage pump of the permanent magnet motor described in this invention, the mechanical seal assembly includes a stationary ring fixed on a conical ring and a rotating ring fixed on an impeller, wherein the stationary ring and the rotating ring provide a rotational seal.

[0015] As a preferred embodiment of the water-cooled, silent vertical multistage pump of the permanent magnet motor described in this invention, wherein: a piezoelectric ceramic ring for axial compensation is embedded inside the stationary ring.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. In the process of liquid transportation, this invention monitors the interstage pressure difference in real time through a monitoring component. When interstage leakage causes the pressure difference to drop to a set threshold, the movement of the piston will drive the slide and conductive slide to move, switching the circuit from the high-resistance second branch to the low-resistance first branch, thereby reducing the total resistance of the drive circuit. Under a constant power supply voltage, this increases the drive current, which in turn increases the drive torque of the motor, causing the pump shaft to accelerate. The increase in speed is directly used to compensate for the flow rate reduction caused by interstage leakage, thereby maintaining the set flow rate at the pump outlet and ensuring the operating efficiency and stability of the pump transportation system.

[0017] 2. When the interstage pressure difference is detected to decrease to a set threshold, the controller switches the circuit from the second branch to the first branch. Simultaneously, the controller controls the voltage of the piezoelectric ceramic ring to generate a corresponding axial expansion. This expansion force directly drives the axial compensation of the stationary ring, accurately compensating for the wear gap. Since there is a direct correlation between the decrease in pressure difference and the wear gap, the voltage of the piezoelectric ceramic ring can be precisely adjusted. This effectively restores the sealing performance while preventing abnormal wear or operational jamming caused by overcompensation, fundamentally maintaining the long-term stability of the equipment.

[0018] 3. After the piezoelectric ceramic ring compensates for the sealing gap, the increase in pump shaft speed leads to an increase in interstage pressure difference. This increased interstage pressure difference pushes the piston to move in the opposite direction, thereby moving the slide and conductive slide block, switching the circuit from the first branch back to the second branch. With the power supply voltage unchanged, the circuit current returns to normal levels, allowing the equipment to automatically return to a stable normal operating state after compensation. This avoids the heat dissipation pressure caused by continuous high-speed operation, ensuring the long-term reliability and energy efficiency of the equipment.

[0019] 4. When the interstage pressure difference is detected to decrease to a set threshold and the circuit switches from the second branch to the first branch, the indicator light turns off simultaneously. The operator can then determine that the mechanical seal components between the corresponding stages have undergone significant wear and entered an automatic compensation state. This allows for targeted maintenance or replacement after the operating cycle ends, ensuring the long-term reliability of the equipment.

[0020] 5. After compensating for the sealing gap, due to the limited expansion compensation of the piezoelectric ceramic ring, if the seal wear has reached its maximum compensation limit, the interstage pressure difference cannot be restored after secondary or multiple compensations by the piezoelectric ceramic ring. This prevents the piston from reversing and resetting the slide under the action of the pressure difference. Consequently, the circuit will remain in the low-resistance first branch state and cannot switch back to the second branch, causing the indicator light to remain off for a long time. After the controller continuously monitors the indicator light and detects that it has been off for more than the preset time, it will actively issue a warning signal. This signal clearly indicates to the operator that the moving ring and stationary ring at the corresponding position of the indicator light need to be inspected or replaced immediately, thereby ensuring the long-term reliability of the equipment. Attached Figure Description

[0021] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0022] Figure 2 This is a schematic diagram of the first cross-sectional structure of the present invention.

[0023] Figure 3 This is a schematic diagram of the second cross-sectional structure of the present invention.

[0024] Figure 4 This is a three-dimensional structural diagram of the pump shaft assembly of the present invention.

[0025] Figure 5 This is a schematic diagram of the three-dimensional structure of the impeller assembly of the present invention.

[0026] Figure 6 This is a schematic cross-sectional view of the impeller assembly structure of the present invention.

[0027] Figure 7 for Figure 6 A magnified structural diagram at point A.

[0028] Figure 8 for Figure 6 A magnified structural diagram at point B.

[0029] Figure 9 This is a schematic diagram of the first cross-sectional structure of the monitoring component assembly of the present invention.

[0030] Figure 10 This is a schematic diagram of the second cross-sectional structure of the monitoring component assembly of the present invention.

[0031] Figure 11This is a schematic diagram of the circuit connection between the driving component and the monitoring component of the present invention.

[0032] In the diagram: 1. Base; 11. Inlet pipe; 12. Outlet pipe; 13. Outer cylinder; 14. Inner cylinder; 15. Flow channel; 16. Flow port; 2. Controller; 3. Pump shaft; 31. Conical ring; 311. Stationary ring; 312. Piezoelectric ceramic ring; 32. Impeller; 321. Moving ring; 33. Guide vane; 34. Conical top ring; 35. Support frame; 4. Excitation winding; 41. Inner magnetic frame; 42. Permanent magnet; 43. Isolation sleeve; 5. Mounting seat; 51. Through hole; 52. Piston; 53. Spring; 54. Fixing ring; 55. Slide; 551. First push rod; 552. Second push rod; 56. Conductive slide; 561. First branch; 562. Second branch; 563. Third branch; 57. Resistor; 58. Indicator light. Detailed Implementation

[0033] The features and exemplary embodiments of various aspects of the present invention will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. The invention is by no means limited to any specific configurations and algorithms presented below, but covers any modifications, substitutions, and improvements to elements, components, and algorithms without departing from the spirit of the invention. Well-known structures and techniques are not shown in the drawings and the following description in order to avoid unnecessarily obscuring the invention.

[0034] Example 1, referring to Figure 1-11 The first embodiment of the present invention provides a water-cooled, quiet vertical multistage pump with a permanent magnet motor. This water-cooled, quiet vertical multistage pump with a permanent magnet motor includes a base 1 and an inner cylinder 14 and an outer cylinder 13 fixed on the base 1. A pump shaft 3 is rotatably connected to the base 1. A drive assembly for driving the pump shaft 3 is provided at the top of the inner cylinder 14. Multiple conical rings 31 are fixedly installed on the inner side of the inner cylinder 14. Impellers 32 corresponding to the conical rings 31 are coaxially fixed on the outer side of the pump shaft 3. A mechanical seal assembly is provided between the inner hole of each set of conical rings 31 and the outer wall of the impeller 32. A monitoring assembly is provided on each conical ring 31. The monitoring component includes a mounting base 5 that passes through a conical ring 31 and a slide 55 that is slidably connected in the mounting base 5. The mounting base 5 has a through hole 51, and a piston 52 is slidably connected in the through hole 51. The displacement of the piston 52 drives the slide 55 to slide, and a conductive slide block 56 is fixedly installed on the slide 55. The monitoring component also includes a first branch 561, a second branch 562 and a third branch 563. The total resistance of the second branch 562 is greater than that of the first branch 561. The conductive slide 56 slides so that one end is electrically connected to one end of the first branch 561 and the second branch 562 respectively, and the other end of the conductive slide 56 is electrically connected to the third branch 563. The other ends of the first branch 561 and the second branch 562 are electrically connected and then connected in series with the third branch 563 in the circuit of the drive component.

[0035] The second branch 562 contains a resistor 57 and an indicator light 58 connected in series. The first branch 561 and the third branch 563 are both composed of wires.

[0036] A retaining ring 54 is fixedly installed inside the through hole 51. A spring 53 is fixedly connected between the retaining ring 54 and the piston 52. A first push rod 551 and a second push rod 552 with their ends extending into the through hole 51 are fixedly installed at the upper and lower ends of the slide 55, respectively. The first push rod 551 and the second push rod 552 are located on the upper and lower sides of the piston 52, respectively.

[0037] A flow channel 15 is provided between the inner cylinder 14 and the outer cylinder 13. A flow port 16 is provided at the top of the inner cylinder 14. An inlet pipe 11 and an outlet pipe 12 are fixed on the base 1. The inlet pipe 11 is connected to the inside of the inner cylinder 14, and the outlet pipe 12 is connected to the flow channel 15.

[0038] A controller 2 is fixedly installed on the top of the outer cylinder 13.

[0039] A conical top ring 34 is fixed inside the inner cylinder 14. Multiple guide vanes 33 are rotatably connected to the outside of the pump shaft 3 above each impeller 32. The uppermost guide vane 33 is fixedly connected to the bottom of the conical top ring 34, and the other guide vanes 33 are fixedly connected to the conical ring 31 above it.

[0040] The drive assembly includes an excitation winding 4 fixed inside the outer cylinder 13 and an inner magnetic frame 41 coaxially fixedly connected to the pump shaft 3. Multiple permanent magnets 42 are fixed in a circumferential array inside the inner magnetic frame 41. An isolation sleeve 43 is provided between the inner magnetic frame 41 and the excitation winding 4. The isolation sleeve 43 is fixedly connected between the top of the inner cylinder 14 and the outer cylinder 13.

[0041] A support frame 35 is fixedly installed inside the inner cylinder 14, and the pump shaft 3 is rotatably connected to the support frame 35.

[0042] The mechanical seal assembly includes a stationary ring 311 fixed on a conical ring 31 and a rotating ring 321 fixed on an impeller 32, with a rotational seal between the stationary ring 311 and the rotating ring 321.

[0043] During use, when the circuit power is turned on, the current that flows in is a current with an ordered phase change, which causes the excitation winding 4 to generate a rotating electromagnetic field. This rotating magnetic field penetrates the isolation sleeve 43 and interacts with the magnetic field generated by the multiple permanent magnets 42 on the inner magnetic frame 41, thereby driving the multiple permanent magnets 42 on the inner magnetic frame 41 to rotate. The permanent magnets 42 directly drive the pump shaft 3 to rotate, and the pump shaft 3 drives the multiple impellers 32 that are fixed coaxially with it to rotate around the central axis of the inner magnetic frame 41. The conveying medium enters the inner cylinder 14 through the inlet pipe 11. When multiple impellers 32 rotate, the conveying medium entering the impeller 32 is radially thrown out by the blades of the impeller 32, thereby pressurizing the conveying medium. At the same time, the bottom of the impeller 32 continuously draws the conveying medium from the inner cylinder 14 into the impeller 32. The suction at the bottom of the upper impeller 32 causes the conveying medium to move along the guide vane 33 to the bottom of the impeller 32 and be drawn into the impeller 32. Thus, with the gradual acceleration of multiple impellers 32, the conveying medium is gradually pressurized. After the conveying medium is lifted to the top of the inner cylinder 14, it enters the flow channel 15 between the inner cylinder 14 and the outer cylinder 13 through the flow port 16, and finally flows along the flow channel 15 to the outlet pipe 12 for discharge, thereby realizing multi-stage pumping of the conveying medium.

[0044] Initially, piston 52, under the action of spring 53, pushes the end of the first push rod 551, causing the slide 55 and conductive slide 56 to be positioned near the top. At this time, the end of conductive slide 56 is connected to the first branch 561. The excitation winding 4 of the drive assembly is connected to the first branch 561, the second branch 562, the third branch 563 and the conductive slide 56 of the monitoring assembly according to... Figure 11 The circuit shown is electrically connected. During pump startup, when the power is turned on, the excitation winding 4 is in a high-current state, thereby driving the pump shaft 3 to rotate at high speed, which in turn drives the impeller 32 to rotate at high speed. The rotation of the impeller 32 creates a pressure difference on both sides of the corresponding conical ring 31. Due to the high-speed rotation of the pump shaft 3, the pressure difference on both sides of the conical ring 31 is higher than the pressure difference during operation. At this time, the liquid pressure difference on both sides of the conical ring 31 pushes the piston 52 to move downward and compresses the spring 53 at the same time. The piston 52 moves downward until it pushes the second push rod 552 to move downward, thereby driving the slide 55 and the conductive slide... The seat 56 moves downward, so that the end of the conductive slide 56 is connected to the second branch 562. At this time, the resistor 57 is connected to the circuit, which increases the total resistance and reduces the circuit current, thereby reducing the speed of the pump shaft 3 driven by the drive assembly. At the same time, when the second branch 562 is connected, the indicator light 58 lights up. After all the indicator lights 58 are lit, the drive assembly drives the pump shaft 3 to rotate at a stable speed, realizing the stable delivery of the medium. At this time, the pressure difference on both sides of the conical ring 31 is stable, so that the piston is stably stopped between the first push rod 551 and the second push rod 552.

[0045] During the conveying of the medium, the interstage pressure difference is monitored in real time by the monitoring component. Due to prolonged high-speed relative operation, wear inevitably occurs between the stationary ring 311 and the rotating ring 321 of the mechanical seal assembly. As wear gradually accumulates, the sealing gap gradually increases, leading to increased interstage leakage. This leakage causes the pressure difference to gradually decrease. When the pressure difference decreases to a set threshold, the spring force of the corresponding spring 53 causes the corresponding piston 52 to move upward. The movement of the piston 52 pushes the first push rod 551 upward, thereby driving the slide 55 and the guide... The electric slide 56 moves upward, causing the end of the conductive slide 56 to switch from the high-resistance second branch 562 to the low-resistance first branch 561. The resistor 57 is disconnected from the circuit, thereby reducing the total resistance of the drive circuit. Under a constant power supply voltage, the drive current increases, which in turn increases the current flowing through the excitation winding 4. The increase in current increases the drive torque of the permanent magnet motor, causing the pump shaft 3 to rotate faster. The increase in the speed of the pump shaft 3 is directly used to compensate for the flow attenuation caused by interstage leakage, thereby maintaining the pump outlet at a stable set flow rate and ensuring the operating efficiency and stability of the pump delivery system.

[0046] The pump shaft 3 and the stationary ring 311 and rotating ring 321 of the mechanical seal assembly are always immersed in the conveying medium, so that the low-temperature conveying medium carries away the heat generated by mechanical friction during the conveying process. Then, after the liquid is lifted to the top of the inner cylinder 14 by the multi-stage impeller 32, some liquid enters the interior of the isolation sleeve 43, so that the inner magnetic frame 41 is immersed in the conveying medium, so that the conveying medium absorbs the eddy current heat generated during the electromagnetic coupling transmission torque, thereby achieving cooling. In addition, after the conveying medium enters the flow passage 15, the conveying medium contacts the outside of the isolation sleeve 43, which can absorb and carry away the resistance heat generated by the excitation winding 4, thereby achieving effective water cooling of the pump.

[0047] During the conveying process, the inner cylinder 14 and the flow passage 15 between the inner cylinder 14 and the outer cylinder 13 are filled, so that a liquid layer is formed on the outside of the pump's transmission components. The liquid layer can effectively isolate the noise generated by the transmission components due to friction or vibration, thereby achieving the effect of silent conveying.

[0048] In summary, the liquid carries away the heat from the motor and the transmission components through the internal circulation system. At the same time, the circulating liquid effectively isolates the noise generated by the movement, greatly reducing the noise of the pump. It is a new generation of environmentally friendly product with a more user-friendly design, and is especially suitable for use in places with high requirements for environmental noise.

[0049] Example 2, refer to Figure 4-11 This is the second embodiment of the present invention, which differs from the first embodiment in that: The mechanical seal assembly includes a stationary ring 311 fixed on a conical ring 31 and a rotating ring 321 fixed on an impeller 32, with a rotational seal between the stationary ring 311 and the rotating ring 321.

[0050] The stationary ring 311 has a piezoelectric ceramic ring 312 embedded inside for axial compensation.

[0051] Preferably, indicator light 58 is located on the top of controller 2.

[0052] During operation, when the interstage pressure difference is detected to decrease to a set threshold, the movement of piston 52 switches the circuit from the second branch 562 to the first branch 561. At the same time, controller 2 receives the circuit switching signal and synchronously controls the input voltage of piezoelectric ceramic ring 312, causing piezoelectric ceramic ring 312 to generate corresponding axial expansion when its input voltage increases. This expansion force can directly drive stationary ring 311 to perform axial compensation, which is used to accurately compensate for the wear gap between stationary ring 311 and moving ring 321. Since there is a direct correlation between the decrease in pressure difference and the wear gap, the pressure difference decreases to the set threshold with precision, allowing the voltage of piezoelectric ceramic ring 312 to be precisely adjusted accordingly. Thus, while the expansion of piezoelectric ceramic ring 312 effectively restores the sealing performance, it prevents abnormal wear or operational jamming caused by overcompensation, fundamentally ensuring the long-term stability of the equipment.

[0053] After the interstage pressure difference is detected to decrease to the set threshold and the piezoelectric ceramic ring 312 is triggered to compensate for the sealing gap, the interstage pressure difference increases due to the increase in the speed of the pump shaft 3 driven by the drive assembly. The liquid pressure difference on both sides of the conical ring 31 pushes the piston 52 downward and compresses the spring 53 at the same time. The piston 52 moves downward until it pushes the second push rod 552 downward, which in turn drives the slide 55 and the conductive slide 56 downward, so that the end of the conductive slide 56 is connected to the second branch 562. Under the condition that the power supply voltage remains unchanged, the resistor 57 is connected to the circuit at this time, which increases the total resistance of the circuit, reduces the circuit current and restores it to the normal level. This reduces the speed of the pump shaft 3 driven by the drive assembly, so that the equipment can automatically return to a stable normal operating state after the compensation is completed. This avoids the heat dissipation pressure caused by continuous high-speed operation, and ensures the long-term operational reliability and energy efficiency of the equipment.

[0054] After monitoring that the interstage pressure difference has decreased to the set threshold and triggering compensation, the indicator light 58 turns off when the circuit switches from the second branch 562 to the first branch 561. The operator can then determine that the mechanical seal components between the corresponding stages have undergone significant wear and that the piezoelectric ceramic ring 312 has entered the automatic compensation state. This allows for targeted maintenance or replacement after the operating cycle ends, ensuring the long-term reliability of the equipment.

[0055] After compensating for the sealing gap, based on the limited expansion compensation of the piezoelectric ceramic ring 312, if the seal wear has reached its maximum compensation limit, the interstage pressure difference after secondary or multiple compensations of the piezoelectric ceramic ring 312 will still not be able to recover. This will prevent the piston 52 from moving downward under the pressure difference to push the second push rod 552 downward, thus preventing the slide 55 from reversing and resetting. As a result, the motor circuit will remain in the low-resistance first branch 561 state and will not be able to switch back to the second branch 562, causing the indicator light 58 to remain off for a long time. After the controller 2 continuously monitors that the indicator light 58 has been off for more than a preset time, it will actively issue a warning signal. This signal clearly indicates that the operator needs to immediately inspect or replace the moving ring 321 and stationary ring 311 at the corresponding position of the indicator light 58, thereby ensuring the long-term reliability of the equipment.

[0056] In summary, when a decrease in interstage pressure difference due to seal wear is detected, controller 2 simultaneously triggers a dual response: on the one hand, it increases the pump speed through circuit switching to maintain instantaneous flow; on the other hand, it precisely adjusts the voltage of the piezoelectric ceramic ring 312 to drive the displacement of the stationary ring 311 to compensate for wear gaps in real time. After compensation, the system can automatically reset to normal operating conditions based on the restored pressure difference. Simultaneously, the status of indicator light 58 provides intuitive indication of wear and compensation status. When wear exceeds the compensation limit, the system can proactively issue a replacement warning based on the constantly off state of indicator light 58 and the delay judgment of controller 2. This achieves full-cycle intelligent maintenance from real-time compensation to failure warning, greatly improving the operational reliability of the equipment.

[0057] The remaining structure is the same as that in Example 1.

[0058] Different technical features appearing in different embodiments can be combined to achieve beneficial effects. Those skilled in the art, based on a study of the drawings, specification, and claims, should be able to understand and implement other variations of the disclosed embodiments. In the claims, the term "comprising" does not exclude other means or steps; the indefinite article "a" does not exclude a plurality; the terms "first" and "second" are used to identify names rather than to indicate any particular order. No reference numerals in the claims should be construed as limiting the scope of protection. The functionality of multiple parts appearing in the claims can be implemented by a single hardware or software module. The appearance of certain technical features in different dependent claims does not mean that these technical features cannot be combined to achieve beneficial effects.

Claims

1. A water-cooled, low-noise vertical multistage pump powered by a permanent magnet motor, characterized in that: The device includes a base and an inner cylinder and an outer cylinder fixed on the base. A pump shaft is rotatably connected to the base. A drive assembly for driving the pump shaft is provided on the top of the inner cylinder. Multiple conical rings are fixedly installed on the inner side of the inner cylinder. Impellers corresponding to the conical rings are coaxially fixed on the outer side of the pump shaft. A mechanical seal assembly is provided between the inner hole of each set of conical rings and the outer wall of the impeller. A monitoring assembly is provided on each conical ring. The monitoring component includes a mounting base that passes through a conical ring and a slide that is slidably connected to the mounting base. The mounting base has a through hole, and a piston is slidably connected to the through hole. The displacement of the piston drives the slide to slide, and a conductive slide is fixedly mounted on the slide. The monitoring component further includes a first branch, a second branch, and a third branch. The total resistance of the second branch is greater than that of the first branch. The conductive slide block slides so that one end of it is electrically connected to one end of the first branch and one end of the second branch, respectively, and the other end of the conductive slide block is electrically connected to the third branch. The other ends of the first and second branches are electrically connected and then connected in series with the third branch in the circuit of the drive component.

2. The water-cooled, silent vertical multistage pump for a permanent magnet motor according to claim 1, characterized in that: The second branch contains a resistor and an indicator light connected in series, while the first and third branches are both composed of wires.

3. A water-cooled, quiet vertical multistage pump for a permanent magnet motor according to claim 1, characterized in that: A fixing ring is fixedly installed inside the through hole, and a spring is fixedly connected between the fixing ring and the piston. A first push rod and a second push rod with their ends extending into the through hole are fixedly installed at the upper and lower ends of the slide respectively. The first push rod and the second push rod are located on the upper and lower sides of the piston respectively.

4. A water-cooled, quiet vertical multistage pump for a permanent magnet motor according to claim 1, characterized in that: A flow channel is provided between the inner cylinder and the outer cylinder. A flow port is provided at the top of the inner cylinder. An inlet pipe and an outlet pipe are fixed on the base. The inlet pipe is connected to the inside of the inner cylinder, and the outlet pipe is connected to the flow channel.

5. A water-cooled, quiet vertical multistage pump for a permanent magnet motor according to claim 1, characterized in that: A controller is fixedly installed on the top of the outer cylinder.

6. A water-cooled, quiet vertical multistage pump for a permanent magnet motor according to claim 1, characterized in that: A conical top ring is fixed inside the inner cylinder. Multiple guide vanes are rotatably connected to the outside of the pump shaft above each impeller. The uppermost guide vane is fixedly connected to the bottom of the conical top ring, and the remaining guide vanes are fixedly connected to the conical ring above them.

7. A water-cooled, quiet vertical multistage pump for a permanent magnet motor according to claim 1, characterized in that: The drive assembly includes an excitation winding fixed inside the outer cylinder and an inner magnetic frame fixedly connected coaxially with the pump shaft. Multiple permanent magnets are fixed in a circumferential array inside the inner magnetic frame. An isolation sleeve is provided between the inner magnetic frame and the excitation winding. The isolation sleeve is fixedly connected between the top of the inner cylinder and the outer cylinder.

8. A water-cooled, quiet vertical multistage pump for a permanent magnet motor according to claim 1, characterized in that: A support frame is fixedly installed inside the inner cylinder, and the pump shaft is rotatably connected to the support frame.

9. A water-cooled, quiet vertical multistage pump for a permanent magnet motor according to claim 1, characterized in that: The mechanical seal assembly includes a stationary ring fixed to a conical ring and a rotating ring fixed to an impeller, wherein the stationary ring and the rotating ring provide a rotatable seal.

10. A water-cooled, quiet vertical multistage pump for a permanent magnet motor according to claim 9, characterized in that: The stationary ring contains a piezoelectric ceramic ring for axial compensation.

Images