Shield pump

Abstract

The invention provides a shield pump, and belongs to the technical field of water pumps. A shield pump comprises a motor shell, a pump body, a junction box and an exhaust pipe, a pump cavity communicated with the outside is formed in the pump body, a rotating shaft with an air passing channel is arranged in the motor shell, the rotating shaft is sleeved with a shielding sleeve fixed in the motor shell, a cavity communicated with the pump cavity is formed between the rotating shaft and the shielding sleeve, and the exhaust pipe is communicated with the cavity. The lower end of the exhaust pipe is inserted into the top of the shielding sleeve and is welded and positioned on the shielding sleeve, the junction box is detachably connected to the top of the motor shell, a positioning hole coaxial with the exhaust pipe is formed in the junction box, the upper end of the exhaust pipe is inserted and positioned in the positioning hole and is in sealed connection with the positioning hole through a sealing piece, and a deflation bolt is inserted into the top of the junction box; and the deflation bolt is screwed at the upper end of the exhaust pipe. Through welding of the exhaust pipe and the shielding sleeve and the positioning hole of the junction box, the exhaust pipe and the rotating shaft, the shield pump which is more stable in operation is provided.

Description

Technical Field

[0001] The present invention belongs to the technical field of water pumps and relates to a canned motor pump. Background Art

[0002] A canned motor pump belongs to a type of pump. In a canned motor pump, the pump and the motor are connected together. The rotor of the motor and the impeller of the pump are fixed on the same shaft, and a shielding sleeve is used to separate the rotor and the stator of the motor. Generally, a canned motor pump is used to transport liquids. Before the liquid enters the pump chamber, it needs to overcome the pressure in the pump chamber. If there is gas in the pump chamber, the liquid will not be able to enter the pump chamber normally, resulting in the pump not working properly. Therefore, to ensure the normal operation of the pump.

[0003] For example, a vertically-mounted multi-stage canned motor pump with bearings that are not easily worn, disclosed in the patent application No. 202211482347.5, includes a motor housing, a combined cover, a pressure tank, a pump body, and a pump base that are connected in sequence from top to bottom. A rotating shaft is also provided inside the motor housing. An exhaust pipe is screwed to the top of the rotating shaft. The motor housing has an upper end cover, and an exhaust nut is screwed to the upper end cover. The above solution uses a screwing method to connect the components for exhaust to the rotating shaft, and by opening the exhaust nut, the canned motor pump is fully exhausted to ensure the normal operation of the pump. However, when the canned motor pump is running, the rotating shaft will drive the components screwed to it to rotate together. During the rotation process, it is easy to become loose. The position and angle of the exhaust pipe may change, and the force borne by the rotating shaft may not be evenly distributed, resulting in irregular swinging or vibration of the exhaust pipe during the operation of the pump, thereby affecting the rotational stability of the pump. Unstable rotation will cause the performance of the pump to decline, generate noise and vibration, and may cause wear and damage to other mechanical components. At the same time, it will also impose additional loads on key components such as bearings and seals, reducing their service life and reliability.

[0004] To avoid loosening between the rotating shaft and the exhaust pipe when the rotating shaft rotates, what those skilled in the art can easily think of is to fix the exhaust pipe to the rotating shaft by connection methods such as welding and glue connection, or directly increase the axial length of the rotating shaft. Whether it is fixing the exhaust pipe to the rotating shaft or directly increasing the axial length of the rotating shaft, it makes the rotating shaft longer. A longer rotating shaft has a greater inertia, which means that more force and more time are required to change its rotating state, resulting in a slower response time and a reduced working efficiency of the canned motor pump. Summary of the Invention

[0005] The object of the present invention is to address the above problems existing in the prior art and propose a canned motor pump. The technical problem to be solved by the present invention is: how to provide a canned motor pump with more stable operation.

[0006] To achieve the above object, the present invention is implemented through the following technical solutions: A canned motor pump includes a motor housing, a pump body, a junction box, and an exhaust pipe. The pump body has a pump chamber communicating with the outside. The motor housing is provided with a rotating shaft having an air passage. A shielding sleeve fixed in the motor housing is sleeved outside the rotating shaft. It is characterized in that there is a cavity communicating with the pump chamber between the rotating shaft and the shielding sleeve. The exhaust pipe communicates with the cavity. The lower end of the exhaust pipe is inserted into the top of the shielding sleeve and welded and positioned on the shielding sleeve. The junction box is detachably connected to the top of the motor housing. The junction box has a positioning hole coaxial with the exhaust pipe. The upper end of the exhaust pipe is inserted and positioned in the positioning hole and is hermetically connected to the positioning hole through a sealing member. A bleed bolt is inserted into the top of the junction box, and the bleed bolt is screwed onto the upper end of the exhaust pipe.

[0007] Before running the canned motor pump, loosen the bleed bolt and then start the canned motor pump. The gas sequentially passes through the pump chamber, the air passage, the cavity, and the exhaust pipe and is discharged to the outside of the pump. After water is discharged from the exhaust pipe, tighten the bleed bolt to complete the exhaust. After the exhaust, the canned motor pump runs normally. The gas flow path during exhaust becomes the water flow path, forming an internal circulation of the canned motor pump to cool the rotating shaft. Since the exhaust pipe is inserted into the junction box, water also flows in the exhaust pipe during the internal circulation to cool the junction box.

[0008] Replace the connection between the exhaust pipe and the rotating shaft with the connection between the exhaust pipe and the shielding sleeve, so that the exhaust pipe does not rotate when the rotating shaft rotates. The independent design can reduce the transmission of vibration and noise in the canned motor pump. The connection between the exhaust pipe and the shielding sleeve is welded instead of the most conventional screwed connection. On the one hand, because screwed connection has relatively high requirements for the coaxiality of the shielding sleeve and the exhaust pipe, and thus relatively high requirements for the tapping accuracy of the threads of the shielding sleeve and the exhaust pipe. Insufficient accuracy will cause gaps at the thread connection, resulting in water entering the junction box and reducing the service life of the junction box. By welding, first, the requirements for the coaxiality of the shielding sleeve and the exhaust pipe are relatively low. On the other hand, in daily production activities, the production accuracy of the shielding sleeve is relatively low, which may cause deviations in the cutting, stamping, forming, etc. links during the production and manufacturing of the shielding sleeve, resulting in possible inclination of the central axis of the produced canned motor pump. Welding can appropriately adjust the welding position and angle of the exhaust pipe to eliminate the deviations in the production accuracy of the shielding sleeve, ensure that the axis of the exhaust pipe is collinear with the axis of the rotating shaft after the exhaust pipe is fixed, and finally make the positioning hole of the junction box, the exhaust pipe, and the rotating shaft coaxial. While ensuring the rotation stability of the rotating shaft, it reduces the exhaust resistance, improves the exhaust efficiency, and also makes the center of gravity of the entire canned motor pump more concentrated and stable, forming a high balance degree, avoiding the center of gravity deviation, reducing the vibration conduction and the vibration caused by imbalance, and improving the operation stability.

[0009] The upper end of the exhaust pipe is inserted and positioned in the positioning hole of the junction box, and the lower end is welded to the shielding sleeve, which increases the stability of the exhaust pipe and ensures the connection life between the exhaust pipe and the shielding sleeve. The setting of the seal improves the sealing performance of the junction box, prevents the water or water vapor discharged from the exhaust pipe from penetrating into the junction box, ensures the life of the junction box, and improves the reliability and stability of the operation of the canned motor pump. The circulating water in the internal circulation cools the rotating shaft and the junction box, further ensuring the performance of the canned motor pump and improving the stability of the operation of the canned motor pump.

[0010] In the above-mentioned canned motor pump, the top end of the canned motor pump bends inward to form a welding part. The welding part has an annular inner peripheral wall, and the space enclosed by the annular inner peripheral wall forms an insertion hole. The lower end of the exhaust pipe is inserted into the insertion hole. A welding surface is formed at the bending part of the welding part. An annular fixing ring protrudes outward along the circumference of the exhaust pipe. The fixing ring is close to the lower end of the exhaust pipe and is welded to the welding surface. The insertion hole plays a role in limiting the exhaust pipe. Welding the fixing ring and the welding surface enables welding operations on the outer circumference of the exhaust pipe while the fixing ring can increase the contact area with the welding surface, improve the reliability of welding, and avoid deformation of the exhaust pipe itself caused by the thermal stress generated during welding.

[0011] In the above-mentioned canned motor pump, there is an adjustment gap between the annular inner peripheral wall of the welding part and the inserted part of the exhaust pipe. The existence of the adjustment gap between the annular inner peripheral wall of the welding part and the exhaust pipe can reserve a certain adjustment space for the position and angle adjustment of the exhaust pipe to facilitate adjusting the exhaust pipe to be coaxial with the rotating shaft.

[0012] In the above-mentioned canned motor pump, the upper end of the rotating shaft is positioned in the shielding sleeve through the upper bearing, and there is a ventilation gap between the rotating shaft and the upper bearing that connects the exhaust pipe and the cavity. The ventilation gap can connect the exhaust pipe and the cavity to ensure the smooth discharge of air. The rotating shaft is limited by the upper bearing to improve the stability of the rotating shaft.

[0013] In the above-mentioned canned motor pump, the two sides of the pump body are respectively provided with a water inlet and a water outlet communicating with the pump cavity. The air passage is arranged along the axial direction of the rotating shaft, and ventilation holes are radially formed on the rotating shaft to communicate the cavity with the air passage. During exhaust, water flows in from the water inlet and out from the water outlet. The pressure of water is higher than that of air, thus pushing the air to move upward. Since the air rises faster in the vertical passage, the vertical exhaust path can conform to its characteristics, reduce the exhaust resistance, and achieve efficient natural exhaust, which is beneficial to realizing a more effective exhaust process.

[0014] In the above-mentioned canned motor pump, the seal is a sealing ring. Using the sealing ring as the seal has a simple structure, good sealing effect, and low cost.

[0015] In the above-mentioned canned motor pump, the motor housing has an upper end cover and a lower end cover. The junction box is sealingly connected to the upper end cover. The lower end cover has a mounting hole. The lower end of the rotating shaft passes through the mounting hole and is rotatably connected to the lower end cover through a lower bearing. The connection between the lower end cover and the rotating shaft through the lower bearing improves the rotational stability of the rotating shaft.

[0016] In the above-mentioned canned motor pump, an impeller is provided in the pump chamber of the pump body, and the impeller is fixedly sleeved on the lower end of the rotating shaft. The rotating shaft drives the impeller to rotate, generating a centrifugal force to accelerate the water and push the water to flow.

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

[0018] 1. Replace the connection between the exhaust pipe and the rotating shaft with the connection between the exhaust pipe and the shielding sleeve, so that the exhaust pipe does not rotate when the rotating shaft rotates. The independent design can reduce the transmission of vibration and noise in the canned motor pump. The welding method of connection has relatively low coaxiality requirements for the shielding sleeve and the exhaust pipe on the one hand, and on the other hand, the welding position and angle of the exhaust pipe can be appropriately adjusted to eliminate the deviation in the production accuracy of the shielding sleeve, ensuring that the axis of the exhaust pipe is collinear with the axis of the rotating shaft after being fixed. Finally, the positioning hole of the junction box, the exhaust pipe, and the rotating shaft are coaxial, reducing the exhaust resistance and improving the exhaust efficiency while ensuring the rotational stability of the rotating shaft, making the center of gravity of the entire canned motor pump more concentrated and stable, forming a high balance degree, avoiding the center of gravity deviation, reducing vibration conduction and vibration caused by imbalance, and improving the operation stability.

[0019] 2. The upper end of the exhaust pipe is inserted and positioned in the positioning hole of the junction box, and the lower end is welded to the shielding sleeve, increasing the stability of the exhaust pipe, ensuring the connection life between the exhaust pipe and the shielding sleeve. The setting of the sealing member improves the sealing performance of the junction box, preventing the water or water vapor discharged from the exhaust pipe from penetrating into the junction box, ensuring the life of the junction box, and improving the reliability and stability of the operation of the canned motor pump.

[0020] 3. The circulating water of the internal circulation cools the rotating shaft and the junction box, further ensuring the performance of the canned motor pump and improving the operation stability of the canned motor pump. Description of the Drawings

[0021] Figure 1 is the overall structural schematic diagram of this canned motor pump.

[0022] Figure 2 is the overall structural sectional view of this canned motor pump.

[0023] Figure 3 is Figure 2 the enlarged view of area A in

[0024] In the figure, 1 is the motor housing; 11 is the upper end cover; 12 is the lower end cover; 121 is the mounting hole; 2 is the pump body; 21 is the water inlet; 22 is the water outlet; 23 is the pump chamber; 3 is the junction box; 31 is the positioning hole; 4 is the rotating shaft; 41 is the air passage; 42 is the vent hole; 5 is the shield sleeve; 51 is the welding part; 511 is the annular inner peripheral wall; 512 is the insertion hole; 513 is the welding surface; 52 is the cavity; 53 is the ventilation gap; 6 is the exhaust pipe; 61 is the fixing ring; 7 is the adjustment gap; 8 is the air release bolt; 9 is the seal; 101 is the upper bearing; 102 is the lower bearing; 103 is the impeller. Detailed implementation manners

[0025] The following are specific embodiments of the present invention and in combination with the accompanying drawings, the technical solutions of the present invention will be further described, but the present invention is not limited to the following embodiments.

[0026] As Figure 1 and Figure 2 shown, a canned motor pump includes a junction box 3, a motor housing 1 and a pump body 2 connected in sequence from top to bottom. A rotating shaft 4 with an air passage 41 is arranged in the motor housing 1. A shield sleeve 5 fixed in the motor housing 1 is sleeved outside the rotating shaft 4. The two sides of the pump body 2 are respectively provided with a water inlet 21 and a water outlet 22. A pump chamber 23 communicating with the water inlet 21 and the water outlet 22 is arranged in the pump body 2. A cavity 52 communicating with the pump chamber 23 is arranged between the rotating shaft 4 and the shield sleeve 5. The rotating shaft 4 is axially provided with an air passage 41, and the rotating shaft 4 is radially provided with a vent hole 42 capable of communicating the cavity 52 with the air passage 41. The upper end of the rotating shaft 4 is positioned in the shield sleeve 5 through an upper bearing 101.

[0027] The canned motor pump further includes an exhaust pipe 6. The lower end of the exhaust pipe 6 is inserted into the top of the shield sleeve 5 and welded and positioned on the shield sleeve 5. A seal 9 is arranged between the upper end of the exhaust pipe 6 and the positioning hole 31 of the junction box 3. The seal 9 is an O-ring. An air release bolt 8 is inserted into the top of the junction box 3. The air release bolt 8 is screwed on the upper end of the exhaust pipe 6. A ventilation gap 53 communicating the exhaust pipe 6 with the cavity 52 is arranged between the rotating shaft 4 and the upper bearing 101. The motor housing 1 has an upper end cover 11 and a lower end cover 12. The junction box 3 is hermetically and detachably connected to the upper end cover 11. The lower end cover 12 has a mounting hole 121. The lower end of the rotating shaft 4 passes through the mounting hole 121 and is rotatably connected to the lower end cover 12 through a lower bearing 102. An impeller 103 is arranged in the pump chamber 23 of the pump body 2. The impeller 103 is fixedly sleeved on the lower end of the rotating shaft 4.

[0028] Combined with Figure 3, the top of the above-mentioned shielding sleeve 5 has a welding part 51 for the lower end of the exhaust pipe 6 to be inserted and positioned. The welding part 51 is formed by bending the top end of the canned motor pump inward. The lower end of the annular exhaust pipe 6 is inserted into the welding part 51 and welded to the shielding sleeve 5. The junction box 3 has a positioning hole 31 coaxial with the exhaust pipe 6. The upper end of the exhaust pipe 6 is inserted into the positioning hole 31. The welding part 51 has an annular inner peripheral wall 511, and the space enclosed by the annular inner peripheral wall 511 forms an insertion hole 512. The lower end of the exhaust pipe 6 is inserted into the insertion hole 512. The bending part of the welding part 51 forms a welding surface 513. An annular fixing ring 61 protrudes outward in the circumferential direction on the exhaust pipe 6. The fixing ring 61 is close to the lower end of the exhaust pipe 6 and is welded to the welding surface 513. The insertion hole 512 plays a role in limiting the exhaust pipe 6. Welding the fixing ring 61 and the welding surface 513 enables the fixing ring 61 to increase the contact area with the welding surface 513 while welding the outer circumference of the exhaust pipe 6, improving the welding reliability, and can avoid the deformation of the exhaust pipe 6 itself caused by the thermal stress generated during welding. There is an adjustment gap 7 between the annular inner peripheral wall 511 of the welding part 51 and the inserted part of the exhaust pipe 6, improving the convenience of adjusting the position and angle of the exhaust pipe 6.

[0029] Before running the canned motor pump, loosen the air release bolt 8 and then start the canned motor pump. When exhausting, the water flow enters from the water inlet 21 and flows out from the water outlet 22. The pressure of the water is higher than the pressure of the air, so as to push the air to move upward. The gas passes through the pump chamber 23, the air passage 41, the cavity 52 and the exhaust pipe 6 in sequence and is discharged to the outside of the pump. Tighten the air release bolt 8 after water is discharged from the exhaust pipe 6 to complete the exhaust. After the exhaust, the canned motor pump runs normally. The gas flow path during exhaust becomes the water flow path, forming an internal circulation of the canned motor pump to cool the rotating shaft 4. Since the exhaust pipe 6 is inserted into the junction box 3, there is also water flowing in the exhaust pipe 6 during the internal circulation to cool the junction box 3.

[0030] In the present invention, the connection between the exhaust pipe 6 and the rotating shaft 4 is replaced with the connection between the exhaust pipe 6 and the shielding sleeve 5, so that the exhaust pipe 6 does not rotate when the rotating shaft 4 rotates. The independent design can reduce the transmission of vibration and noise in the canned motor pump. The connection between the exhaust pipe 6 and the shielding sleeve 5 is welded instead of the most conventional screwed connection. On the one hand, screwed connection requires relatively high coaxiality of the shielding sleeve 5 and the exhaust pipe 6, and thus relatively high tapping accuracy for the threads of the shielding sleeve 5 and the exhaust pipe 6. Insufficient accuracy will cause gaps at the threaded connection, resulting in water entering the junction box 3 and reducing the service life of the junction box 3. By welding, the requirement for the coaxiality of the shielding sleeve 5 and the exhaust pipe 6 is relatively low. On the other hand, the production accuracy of the shielding sleeve 5 is relatively low in daily production activities, which may cause deviations in the cutting, stamping, forming and other processes in the production and manufacturing of the shielding sleeve 5, resulting in possible inclination of the central axis of the produced canned motor pump. Welding can appropriately adjust the welding position and angle of the exhaust pipe 6 to eliminate the deviations in the production accuracy of the shielding sleeve 5, ensure that the axis of the exhaust pipe 6 is collinear with the axis of the rotating shaft 4 after being fixed, and finally make the positioning hole 31 of the junction box 3, the exhaust pipe 6 and the rotating shaft 4 coaxial. While ensuring the rotation stability of the rotating shaft 4, it reduces the exhaust resistance, improves the exhaust efficiency, makes the center of gravity of the entire canned motor pump more concentrated and stable, forms a high balance degree, avoids the center of gravity deviation, reduces the vibration conduction and the vibration caused by imbalance, and improves the operation stability.

[0031] The upper end of the exhaust pipe 6 is inserted and positioned in the positioning hole 31 of the junction box 3, and the lower end is welded to the shielding sleeve 5, which increases the stability of the exhaust pipe 6 and ensures the connection service life between the exhaust pipe 6 and the shielding sleeve 5. The setting of the seal 9 improves the sealing performance of the junction box 3, prevents the water or water vapor discharged from the exhaust pipe 6 from penetrating into the junction box 3, ensures the service life of the junction box 3, and improves the reliability and stability of the operation of the canned motor pump. The circulating water in the internal circulation cools the rotating shaft 4 and the junction box 3, further ensuring the performance of the canned motor pump and improving the operation stability of the canned motor pump.

[0032] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Those skilled in the art of the present invention can make various modifications or supplements to the described specific embodiments or use similar ways to replace them, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0033] Although terms such as motor housing 1, upper end cover 11, lower end cover 12, mounting hole 121, pump body 2, water inlet 21, water outlet 22, pump chamber 23, junction box 3, positioning hole 31, rotating shaft 4, air passage 41, ventilation hole 42, shielding sleeve 5, welding part 51, annular inner peripheral wall 511, insertion hole 512, welding surface 513, cavity 52, ventilation gap 53, exhaust pipe 6, fixing ring 61, adjusting gap 7, air release bolt 8, seal 9, upper bearing 101, lower bearing 102, impeller 103 are used more frequently in this text, the possibility of using other terms is not excluded. The use of these terms is only for the convenience of describing and explaining the essence of the present invention; interpreting them as any additional limitation is contrary to the spirit of the present invention.

Claims

1. A canned motor pump, comprising a motor housing (1), a pump body (2), a junction box (3) and an exhaust pipe (6), wherein a pump chamber (23) communicating with the outside is provided in the pump body (2), a rotating shaft (4) having an air passage (41) is provided in the motor housing (1), and a shielding sleeve (5) fixed in the motor housing (1) is sleeved outside the rotating shaft (4), characterized in that, There is a cavity (52) communicating with the pump chamber (23) between the rotating shaft (4) and the shielding sleeve (5). The exhaust pipe (6) communicates with the cavity (52). The lower end of the exhaust pipe (6) is inserted into the top of the shielding sleeve (5) and welded and positioned on the shielding sleeve (5). The junction box (3) is detachably connected to the top of the motor housing (1). The junction box (3) has a positioning hole (31) coaxial with the exhaust pipe (6). The upper end of the exhaust pipe (6) is inserted and positioned in the positioning hole (31) and is sealed and connected to the positioning hole (31) through a seal (9). A vent bolt (8) is inserted into the top of the junction box (3), and the vent bolt (8) is screwed onto the upper end of the exhaust pipe (6).

2. The canned motor pump according to claim 1, wherein, The top end of the canned motor bends inward to form a welding part (51). The welding part (51) has an annular inner peripheral wall (511). The space enclosed by the annular inner peripheral wall (511) forms an insertion hole (512). The lower end of the exhaust pipe (6) is inserted into the insertion hole (512). A welding surface (513) is formed at the bending part of the welding part (51). An annular fixing ring (61) protrudes outward in the circumferential direction on the exhaust pipe (6). The fixing ring (61) is close to the lower end of the exhaust pipe (6) and is welded to the welding surface (513).

3. A canned motor pump according to claim 2, characterized in that, There is an adjustment gap (7) between the annular inner peripheral wall (511) of the welding part (51) and the inserted part of the exhaust pipe (6).

4. A canned motor pump according to claim 3, wherein, The upper end of the rotating shaft (4) is positioned in the shielding sleeve (5) through an upper bearing (101). There is a ventilation gap (53) between the rotating shaft (4) and the upper bearing (101) for communicating the exhaust pipe (6) with the cavity (52).

5. A canned motor pump according to any one of claims 1 to 4, characterized in that The two sides of the pump body (2) are respectively provided with a water inlet (21) and a water outlet (22) communicating with the pump chamber (23). The air passing channel (41) is arranged along the axial direction of the rotating shaft (4). A ventilation hole (42) enabling the cavity (52) to communicate with the air passing channel (41) is radially opened on the rotating shaft (4).

6. The canned motor pump according to claim 5, wherein The seal (9) is an O-ring.

7. A canned motor pump according to claim 5, characterized in that, The motor housing (1) has an upper end cover (11) and a lower end cover (12). The junction box (3) is sealed and connected to the upper end cover (11). The lower end cover (12) has a mounting hole (121). The lower end of the rotating shaft (4) passes through the mounting hole (121) and is rotatably connected to the lower end cover (12) through a lower bearing (102).

8. A canned motor pump according to claim 7, characterized in that, An impeller (103) is arranged in the pump chamber (23) of the pump body (2), and the impeller (103) is fixedly sleeved on the lower end of the rotating shaft (4).

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