Liquid ammonia pump with self-balancing assembly

Abstract

The application belongs to the field of submerged liquid pumps, and provides a liquid ammonia submerged liquid pump with a self-balancing assembly, which comprises a pump body, a long rod bolt, a pump suction pipe, a motor, a motor shaft, a magnetic coupling, a pump shaft, a multi-stage impeller, an inducer and a self-balancing assembly. The magnetic coupling comprises a driving magnetic rotor, a driven magnetic rotor and a spacer sleeve. One end of the spacer sleeve is directed towards the driving magnetic rotor and seals the space where the driving magnetic rotor is located. The other end of the spacer sleeve is directed towards the multi-stage impeller. The self-balancing assembly comprises a balancing flow channel. An active sleeve is arranged at the output end of the balancing flow channel. An active nozzle in communication with the balancing flow channel is arranged on the active sleeve. A normally closed port is arranged in the interior of the active nozzle. A branch port for connecting the normally closed port is arranged on the pump suction pipe. First and second balancing springs are arranged at the top and bottom of the active sleeve, respectively. The application has the advantages of reasonable design, good self-balancing performance, high space utilization rate and improved comprehensive utilization rate of the pump, and is suitable for large-scale promotion.

Description

Technical Field

[0001] This invention belongs to the field of submersible pumps, and particularly relates to a liquid ammonia submersible pump with a self-balancing component. Background Technology

[0002] A submersible pump is a leak-free pump in which the motor and pump body are integrated and the entire pump is submerged in the medium being transported. It is primarily used for transporting media in deep pools and storage tanks, such as pumping liquid ammonia into a liquid ammonia storage tank. During actual operation, submersible pumps generate unbalanced forces, such as axial forces and inertial forces.

[0003] Regarding the handling of axial force, single-stage impellers often employ a design with air holes on the impeller, while multi-stage impellers use a balancing drum for balancing. For example, Chinese utility model patent CN219888286U discloses a multi-stage submersible pump that can balance axial force. The balancing chamber where the balancing drum is located needs to be connected to an external balancing pipe / return water pipe to guide the water in the balancing chamber back to the pump inlet. This increases the overall size of the pump. Furthermore, the balancing pipe is often a single pipe with a small diameter. Once it becomes blocked, it cannot balance the axial force, directly affecting the pump's self-balancing performance.

[0004] Regarding the issue of handling impeller inertial forces, current methods mainly involve dynamic and static balancing tests before shipment, using coatings and counterweights to achieve balance. However, there is a lack of mechanisms for automatically balancing the inertial forces generated during actual operation, which has a certain impact on the actual service life of the impeller and pump shaft.

[0005] The Chinese invention patent with publication number CN116696792A discloses a magnetically driven liquid ammonia submersible pump that uses a magnetic coupling to drive the pump shaft. It also uses a single balance pipe to connect the balance chamber and the pump inlet to balance the axial force. Moreover, the magnetic coupling adopts a design where the outer magnetic rotor and the inner magnetic rotor are concentric. This directly results in a significant increase in both the radial and axial dimensions of the pump, and also a significant increase in the number of sections that need to be sealed, thereby increasing the probability of equipment failure. Summary of the Invention

[0006] This invention addresses the technical problems of submersible pumps with built-in magnetic couplings by proposing a liquid ammonia submersible pump with a self-balancing component that features a reasonable design, good self-balancing performance, high space utilization, and improves the overall utilization rate of the pump.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The present invention provides a liquid ammonia submersible pump with a self-balancing component, comprising a pump body, a long rod bolt and at least three pump suction pipes externally disposed on the pump body, the pump suction pipes communicating with the interior of the pump body, a motor disposed inside the pump body, a motor shaft disposed at the power output end of the motor, a magnetic coupling disposed on the motor shaft, a pump shaft disposed at the transmission end of the magnetic coupling, a multi-stage impeller and an inducer disposed on the pump shaft, the magnetic coupling including an active magnetic rotor connected to the motor shaft, a driven magnetic rotor disposed on the transmission side of the active magnetic rotor, and a spacer disposed between the active magnetic rotor and the driven magnetic rotor. The sleeve is connected to the inner wall of the pump body by screws. One end of the sleeve faces the active magnetic rotor and seals the space where the active magnetic rotor is located. The other end of the sleeve faces the multi-stage impeller. A self-balancing assembly is provided between the multi-stage impeller and the sleeve. The self-balancing assembly includes at least three balancing channels that extend from the inner wall of the pump body to its outer wall and communicate with each other. A movable sleeve is provided at the output end of the balancing channel. A movable nozzle communicating with the balancing channel is provided on the movable sleeve. A normally closed port is provided inside the movable nozzle. The movable sleeve is movably mounted on the pump suction pipe. A branch port for connecting the normally closed port is provided on the pump suction pipe. A first balancing spring and a second balancing spring are respectively provided at the top and bottom of the movable sleeve.

[0008] Preferably, the outer wall of the pump body is provided with a movable groove, and a guide nozzle communicating with the balance flow channel is provided in the movable groove, wherein the axial length of the guide nozzle is less than the axial length of the movable nozzle.

[0009] Preferably, the pump body is provided with a connecting plate on its exterior for connecting the long rod bolt and the pump suction pipe. The connecting plate is provided with a cylindrical section, and the interior of the cylindrical section is provided with a blind groove that connects to the pump suction pipe. The axial length of the cylindrical section is greater than the thickness of the connecting plate. A guide section is provided between the cylindrical section and the connecting plate. The axial length of the guide section gradually increases from its connection surface with the cylindrical section to the end of the guide section. The interior of the guide section is provided with a guide port that spirally communicates with the blind groove. The guide port is staggered with the balance flow channel.

[0010] Preferably, the inner wall of the pump body is provided with a plurality of evenly distributed semi-cylindrical positioning protrusions, and the positioning protrusions are provided with semi-annular positioning shoulders. The spacer includes a sealing shoulder that mates with the positioning shoulder. The side of the spacer is curved, and the generatrix of the curved surface is S-shaped.

[0011] Preferably, the spacer has a positioning shaft at its center, one end of the driven magnetic rotor has a groove, a bearing bush that mates with the positioning shaft is provided in the groove, the other end of the driven magnetic rotor has an end cap that nests with the spacer, and the spacer has a self-lubricating oil passage inside for supplying oil to the rotating surfaces of the bearing bush and the positioning shaft.

[0012] Preferably, the self-lubricating oil passage includes an oil ring groove disposed near the edge of the spacer, a plurality of spaced-apart breather holes disposed at the top of the oil ring groove, a breather plug disposed in the breather hole, and at least two V-shaped pre-storage grooves disposed inside the spacer, each pre-storage groove having an oil suction hole disposed at its end offset from the oil ring groove and connected in a U-shape to the side of the axial side of the positioning shaft, the lowest end of the pre-storage groove being higher than the end of the oil suction hole.

[0013] Preferably, the multi-stage impeller includes multiple axially distributed impellers, with mounting sleeves provided between adjacent impellers, multiple impeller flow channels provided inside the impellers, and an inertial force balancing device provided on the rear end face of the impellers.

[0014] Preferably, the inertial force balancing device includes a wear-resistant ring that mates with an annular groove on the impeller. The inner wall of the wear-resistant ring is provided with a plurality of arc-shaped grooves arranged in a circular array. A balancing component is provided in the arc-shaped grooves. The balancing component includes an arc-shaped block. Both ends of the arc-shaped block are provided with clips that engage with the ends of the arc-shaped grooves. A balancing cavity is provided on the contact surface between the arc-shaped block and the annular groove. A special-shaped spring is provided inside the balancing cavity. The special-shaped spring includes three arc-shaped segments arranged in a triangular orientation and mate with the arc-shaped trajectory of the arc-shaped block. Two U-shaped segments are provided between the three arc-shaped segments.

[0015] Preferably, the side of the arc segment is provided with a guide arc groove, and a plurality of counterweight balls are provided in the guide arc groove and distributed along the arc trajectory direction of the guide arc groove.

[0016] Preferably, the edge of the wear-resistant ring is provided with a plurality of wear-resistant blocks that correspond one-to-one with the end of the impeller flow channel, and a welded column connected to the impeller is provided through the wear-resistant ring and the wear-resistant blocks.

[0017] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0018] This invention provides a liquid ammonia submersible pump with a self-balancing component. It utilizes an axial end-face drive magnetic coupling and a balance drum design to drive the pump shaft, effectively reducing the axial dimension requirements of the equipment. By employing a balance flow channel integrated with the pump body and branching off from the pump suction pipe, it automatically balances axial forces without significantly increasing the radial dimension of the equipment. Installing an inertial force balancing device on the impeller dynamically adjusts the rotational inertial force, improving the continuous operation performance of the pump shaft and multi-stage impellers. This invention features a reasonable design, good self-balancing performance, high space utilization, and improves the overall utilization rate of the pump, making it suitable for large-scale promotion. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a perspective view of a liquid ammonia submersible pump with a self-balancing component in one embodiment.

[0021] Figure 2 This is a front view of a liquid ammonia submersible pump with a self-balancing component in an embodiment;

[0022] Figure 3 for Figure 2 A cross-sectional view of a liquid ammonia submersible pump with a self-balancing component along the EE direction;

[0023] Figure 4 for Figure 3 Enlarged view of point A in the middle;

[0024] Figure 5 for Figure 3 Enlarged view of point B in the middle;

[0025] Figure 6 A partial schematic diagram of the pump body provided for an embodiment;

[0026] Figure 7 An exploded view of part of the structure of the self-balancing component;

[0027] Figure 8 A perspective view of the spacer, pump shaft, impeller, and inertial force balancing device provided for the embodiment;

[0028] Figure 9 A three-dimensional view of the spacer;

[0029] Figure 10 An exploded view of the inertial force balancing device and impeller provided for the embodiment;

[0030] Figure 11 A front view of the irregularly shaped spring provided for an embodiment;

[0031] In the above figures: 1. Motor; 2. Long bolt; 3. Pump suction pipe; 4. Pump body; 41. Movable groove; 42. Connecting plate; 43. Cylindrical section; 44. Blind groove; 45. Guide section; 46. Guide port; 47. Positioning protrusion; 5. Magnetic coupling; 51. Driving magnetic rotor; 52. Driven magnetic rotor; 53. Spacer; 531. Sealing shoulder; 532. Positioning shaft; 54. Bearing shell; 55. End cover; 56. Self-lubricating oil passage; 561. Oil ring groove; 562. Pre-reservoir; 563. Suction hole; 57. Breather plug; 6. Pump shaft; 7. Impeller 71. Annular groove; 8. Inducer wheel; 9. Self-balancing assembly; 91. Balancing channel; 92. Movable sleeve; 93. Movable nozzle; 94. Normally closed port; 95. Branch port; 96. First balancing spring; 97. Second balancing spring; 98. Guide nozzle; 10. Inertial force balancing device; 101. Wear-resistant ring; 102. Arc groove; 103. Arc block; 104. Clamp; 105. Irregular spring; 1051. Arc segment; 1052. U-shaped segment; 1053. Guide arc groove; 106. Wear-resistant block; 107. Welded column; 108. Counterweight ball. Detailed Implementation

[0032] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other. For ease of description, the terms "upper," "lower," "left," and "right" appearing below only indicate that they correspond to the upper, lower, left, and right directions in the accompanying drawings and do not limit the structure.

[0033] Numerous specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways than those described herein, and therefore the invention is not limited to the specific embodiments disclosed in the following specification.

[0034] Examples, such as Figures 1-11As shown, the present invention provides a liquid ammonia submersible pump with a self-balancing component, comprising a pump body 4, which includes a pump casing, a pump inlet, and a pump outlet. The pump body 4 is externally equipped with long-rod bolts 2 and at least three pump suction pipes 3. The long-rod bolts 2 sequentially connect the pump inlet, pump casing, and pump outlet. The pump suction pipes 3 communicate with the interior of the pump body 4, connecting from the pump casing to the pump inlet, for outputting the pumped flow rate to the liquid ammonia output path. Further, a motor 1 is internally installed in the pump body 4. The power output end of the motor 1 has a motor shaft, and the motor shaft has a magnetic coupling 5. The transmission end of the magnetic coupling 5 has a pump shaft 6, which has multi-stage impellers and inducer wheels 8. The motor 1 is built into the pump body 4, which has a conduit for threading wires. Both ends of the motor 1 have corresponding mechanical seals and bearings. In addition to establishing a transmission relationship with the motor 1 through the magnetic coupling 5, the pump shaft 6 also has bearings to improve its operating performance. Based on this, the present invention proposes an improvement to the magnetic coupling 5, and adopts a design that eliminates the need for a balancing drum. Instead, it provides a self-balancing component 9 to balance the axial force, which reduces the number of necessary and complex sealing components to a certain extent, and improves the actual operating performance and space efficiency of the equipment.

[0035] Specifically, the magnetic coupling 5 provided by the present invention includes an active magnetic rotor 51 connected to a motor shaft (connection to the motor shaft is a prior art method). A driven magnetic rotor 52 is provided on the transmission side of the active magnetic rotor 51. A spacer 53 is provided between the active magnetic rotor 51 and the driven magnetic rotor 52. The spacer 53 is connected to the inner wall of the pump body 4 by screws. One end of the spacer 53 faces the active magnetic rotor 51 and seals the space where the active magnetic rotor 51 is located. The other end of the spacer 53 faces the multi-stage impeller. A self-... The balancing component 9 includes at least three balancing channels 91 extending from the inner wall of the pump body 4 to its outer wall and communicating with it. The output end of the balancing channel 91 is provided with a movable sleeve 92. The movable sleeve 92 is provided with a movable nozzle 93 communicating with the balancing channel 91. The movable nozzle 93 is provided with a normally closed port 94 inside. The movable sleeve 92 is movably mounted on the pump suction pipe 3. The pump suction pipe 3 is provided with a branch port 95 for connecting the normally closed port 94. The top and bottom of the movable sleeve 92 are respectively provided with a first balancing spring 96 and a second balancing spring 97.

[0036] In this device, the magnetic coupling 5, in addition to its inherent advantages such as overload protection, frictionless operation, and good vibration and noise reduction performance, specifically adopts an axial end-face transmission design instead of an inner and outer magnetic rotor design. This allows the spacer 53 to not only replace the mechanical seal for sealing, especially sealing the axial plane of the active magnetic rotor 51, but also to achieve non-contact transmission between the active magnetic rotor 51 and the driven magnetic rotor 52, ensuring effective power input to the pump shaft 6. With the magnetic coupling 5 provided by this invention, the total axial length is less than the total axial length of the inner and outer magnetic rotors. Furthermore, the use of a balance drum-free design for driving the pump shaft 6 effectively reduces the axial dimension requirements of the equipment.

[0037] Furthermore, regarding the automatic axial force balancing, this invention no longer employs an external balancing pipe / return pipe design to redirect leakage from the balancing chamber back to the pump inlet. Instead, it utilizes a balancing flow channel 91 integrated with the pump body 4. A branch outlet 95 is located on the pump suction pipe 3 to discharge the high pressure on the final stage impeller 7 of the multi-stage impeller from the balancing flow channel 91 to the movable sleeve 92. Under the action of the first balancing spring 96 and the second balancing spring 97, the movable sleeve 92 transmits the axial force to the pump body 4, which then transmits it to the location on the liquid ammonia storage tank where the equipment is directly installed. The high-pressure portion of the flow is pumped away from the branch outlet 95 along the liquid ammonia discharge path. This achieves automatic axial force balancing without significantly increasing the radial dimensions of the equipment. Therefore, this invention is rationally designed, has good self-balancing performance, high space utilization, and is beneficial for improving the overall utilization rate of the pump.

[0038] To improve the balancing performance of the self-balancing component 9, the self-balancing component 9 provided by the present invention employs multiple balancing channels 91, and each balancing channel 91 corresponds to a set of movable sleeve 92, movable nozzle 93, normally closed port 94, branch port 95, first balancing spring 96, and second balancing spring 97. The multi-channel self-balancing design reduces the adverse effects of blockage in a single channel on the axial force balance quality of the entire device, thus improving the device's performance under continuous operation conditions. Furthermore, the pump body 4 provided by the present invention has a movable groove 41 on its outer wall. The movable sleeve 92, together with the movable nozzle 93, can always remain on the groove surface of the movable groove 41 due to the installation conditions of the pump suction pipe 3, and they are in surface-to-surface contact, providing a certain degree of automatic sealing and preventing significant leakage. O-rings can be appropriately installed at both axial ends of the movable sleeve 92 to ensure the quality of its active sealing during dynamic self-adjustment. A guide nozzle communicating with the balancing channel 91 is provided in the movable groove 41, and the axial length of the guide nozzle is less than the axial length of the movable nozzle 93. The balanced flow channel 91 has a circular cross-section, and the guide nozzle has an oblong design with its length aligned with the length of the pump body 4. The radial width of the guide nozzle is smaller than that of the movable nozzle 93. The movable groove 41 provides sufficient axial displacement margin for the movable nozzle 93. When flow is generated in the balanced flow channel 91, the liquid ammonia entering the guide nozzle and the movable nozzle 93 can generate axial thrust on the movable sleeve 92. The movable sleeve 92 is also dynamically constrained by the first balance spring 96 and the second balance. During the process of achieving dynamic balance, the axial force can be transmitted to the pump body 4 through the pump suction pipe 3, and then transmitted to the location where the equipment is directly installed on the liquid ammonia storage tank by the pump body 4. After the normally closed port 94 and the branch port 95 are connected, part of the liquid ammonia flow can be pumped out into the pump suction pipe 3 and output to the target path of the liquid ammonia with the large flow. When the normally closed port 94 and the branch port 95 are not connected, the flow on the balance path of the self-balancing component 9 is not pumped away, but the self-balancing component 9 still performs the automatic balancing function.

[0039] To ensure the pumping performance of this equipment, the pump body 4 provided by the present invention is provided with a connecting plate 42 for connecting the long rod bolt 2 and the pump suction pipe 3. A cylindrical section 43 is provided on the connecting plate 42. A blind groove 44 connected to the pump suction pipe 3 is provided inside the cylindrical section 43. The axial length of the cylindrical section 43 is greater than the thickness of the connecting plate 42. A guide section 45 is provided between the cylindrical section 43 and the connecting plate 42. The axial length of the guide section 45 gradually increases from its connection surface with the cylindrical section 43 to the end of the guide section 45. A guide port 46 is provided inside the guide section 45 and spirally connected to the blind groove 44. The guide port 46 and the balance flow channel 91 are staggered. The connecting plate 42 provides a connection base for the long bolt 2 and the pump suction pipe 3, especially enabling the pump suction pipe 3 to connect with the high-pressure part of the multi-stage impeller to adjust the pumping flow. The cylindrical section 43 and the guide section 45 provide a path for the pump body 4 to connect with the pump suction pipe 3 to establish a connection. This path has a certain helicity and cross-sectional diameter, and in particular, it avoids the balance channel 91, making the balancing action of the balance channel 91 an auxiliary mechanism. For the main pumping action, i.e., the liquid ammonia being pumped away from the pump suction pipe 3, it is not affected by the balance channel 91. From the perspective of the self-balancing process, as an auxiliary mechanism, the continuity of the medium entering its interior is better, the probability of cavitation is lower, which is conducive to improving the smoothness of its self-balancing process and can avoid large noise to a certain extent.

[0040] To improve the utilization rate of the spacer 53, effective improvements are proposed in terms of sealing and flow guidance. For example, the inner wall of the pump body 4 is provided with multiple evenly distributed semi-cylindrical positioning protrusions 47, and the positioning protrusions 47 are provided with semi-annular positioning shoulders. The spacer 53 includes a sealing shoulder 531 that cooperates with the positioning shoulder. The side of the spacer 53 is curved, and the generatrix of the curved surface is S-shaped. In addition to the spacer 53, other sealing structures installed from the location of the magnetic coupling 5 to the motor 1 side also adopt the design of sealing shoulder 531 and are fixed by screws. In this way, the spacer 53 seals the parts of the pump body 4 that do not need to contact the liquid ammonia medium and has high connection reliability. The curved surface design of the spacer 53 can promote the flow of high-pressure liquid ammonia in the direction of the guide port 46 and the balance flow channel 91, and can also reduce the radial load on the driven magnetic rotor 52.

[0041] To improve the rotational performance of the magnetic coupling 5, the spacer 53 provided by the present invention has a positioning shaft 532 at its center, a groove at one end of the driven magnetic rotor 52, a bearing 54 that cooperates with the positioning shaft 532 in the groove, and an end cap 55 that nests and engages with the spacer 53 at the other end of the driven magnetic rotor 52. The spacer 53 has a self-lubricating oil passage 56 inside for supplying oil to the rotating surfaces of the bearing 54 and the positioning shaft 532. The radial dimension of the bearing 54 accounts for no more than 1 / 5 of the radial dimension of the driven magnetic rotor 52 end face, which does not affect the magnetic transmission between the driving magnetic rotor 51 and the driven magnetic rotor 52. Moreover, the bearing 54 and the positioning shaft 532 can play a role in centering and support. In addition, the slot structure of the spacer 53 for installing the driven magnetic rotor 52 can effectively improve the continuous operation quality of the driven magnetic rotor 52. The end cover 55 plays a role in preventing oil leakage. The self-lubricating oil channel 56 can supply oil to the mating surface of the bearing 54 and the positioning shaft 532 through self-lubrication, which helps to extend the effective working cycle of this equipment in the liquid ammonia storage tank.

[0042] Furthermore, the self-lubricating oil passage 56 provided by the present invention includes an oil ring groove 561 disposed near the edge of the spacer 53. The top of the oil ring groove 561 is provided with a plurality of spaced-apart breather holes, and a breather plug 57 is disposed in the breather holes. The interior of the spacer 53 is provided with at least two V-shaped pre-storage grooves 562. The pre-storage groove 562 is provided with an oil suction hole 563 in a U-shape connected to the axial side of the positioning shaft 532 at one end of its offset from the oil ring groove 561. The lowest end of the pre-storage groove 562 is higher than the end of the oil suction hole 563. The oil ring groove 561 stores a certain amount of lubricating oil, and the breather plug 57 balances the oil surface pressure. Under the action of pressure and gravity, the lubricating oil in the oil ring groove 561 is distributed into multiple pre-storage tanks 562. The width of the pre-storage tanks 562 is much smaller than the maximum diameter of the spacer 53, so the lubricating oil in the oil ring groove 561 can ensure that the pre-storage tanks 562 have multiple replenishment cycles. The pressure generated by the continuous rotation between the positioning shaft 532 and the bearing 54 can draw oil from the oil suction hole 563, which draws oil from the pre-storage tanks 562. The oil ring groove 561 replenishes the lubricating oil to the pre-storage tanks 562, thereby achieving self-lubrication between the positioning shaft 532 and the bearing 54, and thus extending the working cycle of this equipment in the liquid ammonia storage tank.

[0043] To improve the self-balancing performance of this equipment, the multi-stage impeller provided by this invention includes multiple axially distributed impellers 7. An mounting sleeve is provided between adjacent impellers 7, providing a reasonable axial movement allowance for the impellers 7. The end of the mounting sleeve for mounting the final stage impeller 7 is limited by an annular positioning ring. Multiple impeller 7 flow channels are provided inside the impellers 7, and an inertial force balancing device is provided on the rear end face of the impellers 7. By installing the inertial force balancing device on the impellers 7, the rotational inertial force can be dynamically adjusted, which is beneficial to improving the continuous operation performance of the pump shaft 6 and the multi-stage impeller.

[0044] More specifically, the inertial force balancing device provided by the present invention includes a wear-resistant ring 101, which cooperates with an annular groove 71 on the impeller 7. The inner wall of the wear-resistant ring 101 is provided with a plurality of arc-shaped grooves 102 arranged in a circular array. A balancing component is provided in the arc-shaped grooves 102. The balancing component includes an arc-shaped block 103. Both ends of the arc-shaped block 103 are provided with clips 104 that engage with the ends of the arc-shaped grooves 102. A balancing cavity is provided on the contact surface between the arc-shaped block 103 and the annular groove 71. A special-shaped spring 105 is provided inside the balancing cavity. The special-shaped spring 105 is installed from the bottom surface of the arc-shaped block 103 into the balancing cavity. The special-shaped spring 105 includes three arc-shaped segments 1051 arranged in a triangular orientation and cooperating with the arc-shaped trajectory of the arc-shaped block 103. Two U-shaped segments 1052 are provided between the three arc-shaped segments 1051. Among them, the wear-resistant ring 101 can improve the wear resistance life of the impeller 7 end face, and also provide an installation base for the balancing components. For example, T-shaped slots are provided at both ends of the arc groove 102, and the arc block 103 can be effectively fixed to the inner side of the wear-resistant ring 101 by two clips 104. Multiple balancing components are evenly arranged on the wear-resistant ring 101 to increase the nodes for inertial force balance adjustment and the rationality of distribution. The irregular spring 105 is a spatial three-dimensional structure. In addition to the two U-shaped segments 1052 as fulcrums, there are also two free ends of the arc segments 1051 as fulcrums. Through the multi-node action and the deformation performance of the arc segments 1051 themselves, the irregular spring 105 can generate torsion and circumferential displacement during the continuous rotation of the impeller 7, thereby automatically balancing the unstable inertial force of the impeller 7.

[0045] Furthermore, the side of the arc segment 1051 provided by the present invention is provided with a guide arc groove 1053, and a plurality of counterweight balls 108 are arranged in the guide arc groove 1053 along the arc trajectory direction of the guide arc groove 1053. The counterweight balls 108 can move along the scribed trajectory of the guide arc groove 1053. When the impeller 7 experiences unstable inertial force, the counterweight balls 108 automatically adjust their respective positions with rotational inertia, and the counterweight balls 108 have reasonable friction with the inner wall of the arc block 103, avoiding excessive rolling frequency of the counterweight balls 108. Thus, the counterweight balls 108 can play a counterweight role. In addition, since they are mostly distributed near the position of maximum rotational inertia of the impeller 7, a good self-balancing effect can be achieved through small automatic adjustments, thereby improving the self-balancing performance of the device.

[0046] To improve the reliability of the inertial force balancing device, the wear-resistant ring 101 provided by this invention is provided with multiple wear-resistant blocks 106 on its edge, each corresponding to one end of the impeller 7 flow channel. Welded posts 107, connecting to the impeller 7, are provided through the wear-resistant ring 101 and the wear-resistant blocks 106. The two end faces of the wear-resistant blocks 106 are arc-shaped and smoothly connect with the impeller 7 flow channel. While ensuring the integrity of the impeller 7 pumping flow channel, this provides an effective welding joint for the wear-resistant ring 101, which is beneficial for improving the reliability of the inertial force balancing device and enhancing the wear resistance of the impeller 7's rotating circumference.

[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A liquid ammonia submersible pump with a self-balancing assembly, comprising a pump body, wherein a long rod bolt and at least three pump suction pipes are externally disposed on the pump body, the pump suction pipes communicating with the interior of the pump body, a motor is disposed inside the pump body, a motor shaft is disposed at the power output end of the motor, a magnetic coupling is disposed on the motor shaft, a pump shaft is disposed at the transmission end of the magnetic coupling, and a multi-stage impeller and an inducer are disposed on the pump shaft, characterized in that, The magnetic coupling includes an active magnetic rotor connected to the motor shaft. A driven magnetic rotor is provided on the transmission side of the active magnetic rotor. A spacer is provided between the active magnetic rotor and the driven magnetic rotor. The spacer is connected to the inner wall of the pump body by screws. One end of the spacer faces the active magnetic rotor and seals the space where the active magnetic rotor is located. The other end of the spacer faces the multi-stage impeller. A self-balancing assembly is provided between the multi-stage impeller and the spacer. The self-balancing assembly includes at least three balancing channels that extend from the inner wall of the pump body to its outer wall and communicate with it. A movable sleeve is provided at the output end of the balancing channel. A movable nozzle communicating with the balancing channel is provided on the movable sleeve. A normally closed port is provided inside the movable nozzle. The movable sleeve is movably mounted on the pump suction pipe. A branch port for connecting the normally closed port is provided on the pump suction pipe. A first balancing spring and a second balancing spring are respectively provided at the top and bottom of the movable sleeve. The outer wall of the pump body is provided with a movable groove, and a guide nozzle communicating with the balance flow channel is provided in the movable groove. The axial length of the guide nozzle is less than the axial length of the movable nozzle. The inner wall of the pump body is provided with multiple evenly distributed semi-cylindrical positioning protrusions. A semi-annular positioning shoulder is provided on each positioning protrusion. The spacer includes a sealing shoulder that mates with the positioning shoulder. The side of the spacer is curved, and the generatrix of the curved surface is S-shaped. A positioning shaft is provided at the center of the spacer. A recess is provided at one end of the driven magnetic rotor, and a bearing bush that mates with the positioning shaft is provided in the recess. The other end of the driven magnetic rotor is provided with an end cap nested with the spacer. The spacer is provided with a self-lubricating oil passage for supplying oil to the rotating surfaces of the bearing and the positioning shaft. The self-lubricating oil passage includes an oil ring groove provided near the edge of the spacer. The top of the oil ring groove is provided with a plurality of spaced-apart breather holes. Breathing plugs are provided in the breather holes. The spacer is provided with at least two V-shaped pre-storage grooves. The pre-storage groove is provided with an oil suction hole in a U-shape connected to the side of the positioning shaft at one end away from the oil ring groove. The lowest end of the pre-storage groove is higher than the end of the oil suction hole.

2. A liquid ammonia submersible pump with a self-balancing component according to claim 1, characterized in that, The pump body is externally provided with a connecting plate for connecting long rod bolts and pump suction pipe. The connecting plate is provided with a cylindrical section. The interior of the cylindrical section is provided with a blind groove that connects to the pump suction pipe. The axial length of the cylindrical section is greater than the thickness of the connecting plate. A guide section is provided between the cylindrical section and the connecting plate. The axial length of the guide section gradually increases from its connection surface with the cylindrical section to the end of the guide section. The interior of the guide section is provided with a guide port that spirally communicates with the blind groove. The guide port is staggered with the balance flow channel.

3. A liquid ammonia submersible pump with a self-balancing component according to claim 1, characterized in that, The multi-stage impeller includes multiple axially distributed impellers, with mounting sleeves provided between adjacent impellers. Multiple impeller flow channels are provided inside each impeller, and an inertial force balancing device is provided on the rear end face of each impeller.

4. A liquid ammonia submersible pump with a self-balancing component according to claim 3, characterized in that, The inertial force balancing device includes a wear-resistant ring that mates with an annular groove on the impeller. The inner wall of the wear-resistant ring is provided with multiple arc-shaped grooves arranged in a circular array. A balancing component is provided in each arc-shaped groove. The balancing component includes an arc-shaped block. Both ends of the arc-shaped block are provided with clips that engage with the ends of the arc-shaped grooves. A balancing cavity is provided on the contact surface between the arc-shaped block and the annular groove. A special-shaped spring is provided inside the balancing cavity. The special-shaped spring includes three arc-shaped segments arranged in a triangular orientation and mate with the arc-shaped trajectory of the arc-shaped block. Two U-shaped segments are provided between the three arc-shaped segments.

5. A liquid ammonia submersible pump with a self-balancing component according to claim 4, characterized in that, The side of the arc segment is provided with a guide arc groove, and a plurality of counterweight balls are provided in the guide arc groove and distributed along the arc trajectory direction of the guide arc groove.

6. A liquid ammonia submersible pump with a self-balancing component according to claim 4 or 5, characterized in that, The edge of the wear-resistant ring is provided with multiple wear-resistant blocks that correspond one-to-one with the end of the impeller flow channel, and welded columns that are connected to the impeller are provided through the wear-resistant ring and the wear-resistant blocks.

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