Exhaust mechanism for centrifugal pump and centrifugal pump

Abstract

The utility model discloses an exhaust mechanism for a centrifugal pump and the centrifugal pump. The centrifugal pump comprises a pump body, a pump shaft, an impeller and a driving mechanism. The pump shaft is rotatably mounted on the pump body, and a sealed cavity is formed in the pump body; the impeller is installed on the pump shaft and located in the sealing cavity, at least one end of the pump shaft is provided with a driving mechanism, the driving mechanism drives the impeller to rotate through the pump shaft, fluid conveying is achieved, the exhaust mechanism comprises an automatic exhaust valve, and the automatic exhaust valve is communicated with a high-pressure area and two low-pressure areas of the sealing cavity of the pump body. Compared with the prior art, according to the exhaust mechanism for the centrifugal pump and the centrifugal pump, the high-pressure area and the two low-pressure areas of the sealed cavity of the pump body are communicated through the automatic exhaust valve, gas in the low-pressure areas can be conveniently exhausted, and accumulated gas in the pump can be completely exhausted.

Description

Technical Field

[0001] This application relates to the field of fluid equipment technology, and in particular to an exhaust mechanism for a centrifugal pump and a centrifugal pump. Background Technology

[0002] like Figure 1 As shown, in the traditional structure of a centrifugal pump, the motor 12 and the pump shaft are connected by a flexible coupling 14 (the coupling 14 is covered by a coupling guard 13). The pump 15 adopts a double-end bearing support structure and requires a shaft seal to isolate the bearing housing from the pump body. Then, the pump shaft is used to connect the impeller, shaft seal, and bearing housing in series. To facilitate on-site installation, the pump and motor are usually mounted as a whole on a common base 11, and the alignment of the pump and motor is adjusted before leaving the factory.

[0003] Centrifugal pumps are typically equipped with an automatic air vent valve on top. The water level in the tank must be higher than the top of the pump so that air can be released from inside the pump when it is not running. Existing venting methods can only discharge gas from the high-pressure area; gas from the low-pressure area cannot be directly discharged. During startup, this may cause vibration and abnormal noise due to gas being drawn into the impeller. Utility Model Content

[0004] To solve the above-mentioned technical problems, the purpose of this utility model is to provide an exhaust mechanism for a centrifugal pump and a centrifugal pump that can conveniently discharge gas from low-pressure areas.

[0005] The technical solution provided by this utility model is as follows:

[0006] An exhaust mechanism for a centrifugal pump, the centrifugal pump including a pump body, a pump shaft, an impeller, and a drive mechanism; the pump shaft is rotatably mounted on the pump body, forming a sealed cavity inside the pump body; the impeller is mounted on the pump shaft and located in the sealed cavity; the drive mechanism is mounted on at least one end of the pump shaft, and the impeller is driven to rotate via the pump shaft through the drive mechanism to realize fluid transportation; the exhaust mechanism includes an automatic exhaust valve, the automatic exhaust valve connecting the high-pressure zone of the sealed cavity of the pump body to two low-pressure zones.

[0007] Preferably, the exhaust mechanism includes a first four-way pipe, which is connected to an automatic exhaust valve, a high-pressure exhaust port of the sealed cavity, and a first pipeline that is connected to two low-pressure exhaust ports of the sealed cavity.

[0008] Preferably, a check valve is provided on the first pipeline that connects the exhaust ports of the two low-pressure zones of the sealed cavity.

[0009] A centrifugal pump comprises a pump body, a pump shaft, an impeller, and a driving mechanism; the pump shaft is rotatably mounted on the pump body to form a sealed cavity inside the pump body; the impeller is mounted on the pump shaft and located in the sealed cavity; the pump shaft is provided with the driving mechanism at least at one end, and the impeller is driven to rotate by the driving mechanism through the pump shaft to realize fluid delivery; the centrifugal pump is provided with the exhaust mechanism as described above.

[0010] Preferably, the centrifugal pump is a double-suction pump, and the driving mechanism comprises axial flux motors mounted at both ends of the pump shaft to form a double-drive double-suction pump.

[0011] Preferably, the axial flux motor comprises a bearing seat, a bearing gland, and a driving rotor; the driving rotor is mounted on the pump shaft and uniformly arranged with a plurality of permanent magnets; the bearing gland is mounted outside the bearing seat to form a cavity surrounding the driving rotor; the bearing gland and the bearing seat are uniformly provided with the same number of first winding blocks and second winding blocks as the permanent magnets.

[0012] Preferably, the bearing seat is provided with a first cooling water cavity, and the first cooling water cavity is sealed by a first water seal plate; the bearing gland is provided with a second cooling water cavity, and the second cooling water cavity is sealed by a second water seal plate; the bearing seat and the driving rotor are further provided with a cooling water coil.

[0013] Preferably, the first cooling water cavity realizes water inlet and outlet through a first cooling water cavity interface, the second cooling water cavity realizes water inlet and outlet through a second cooling water cavity interface, and the cooling water coil realizes water inlet and outlet through a cooling water coil interface; the first cooling water cavity interface, the second cooling water cavity interface, and the cooling water coil interface are all connected to the inside of the pump body through a third pipeline.

[0014] Preferably, a sealing mechanism is arranged between the pump body and the pump shaft; the sealing mechanism comprises a mechanical seal dynamic ring, a mechanical seal static ring, a packing ring, and a packing gland; the mechanical seal dynamic ring is fixed on the pump shaft, the mechanical seal static ring is fixed on the pump body, and the mechanical seal dynamic ring and the mechanical seal static ring seal the sealed cavity; the mechanical seal static ring is provided with a receiving groove for accommodating the packing ring at the outer end, and the packing gland can be installed at the end of the receiving groove and compress the packing ring, so that when the mechanical seal between the mechanical seal dynamic ring and the mechanical seal static ring fails, the packing ring and the packing gland can be installed on the mechanical seal static ring to realize packing seal.

[0015] Preferably, a second four-way pipe is further arranged between the first four-way pipe and the high-pressure area exhaust hole of the sealed cavity; the second four-way pipe is connected to the mechanical seal through two second pipelines to spray water between the mechanical seal dynamic ring and the mechanical seal static ring.

[0016] The utility model is used for the exhaust mechanism and centrifugal pump of centrifugal pump, and the high pressure area and two low pressure areas of pump body sealing cavity are communicated through automatic exhaust valve, can conveniently exhaust the gas of low pressure area, realizes the exhaust of gas accumulation in pump. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical scheme in the embodiments of the present application or prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows, obviously, the drawings in the following description are only some embodiments described in the present application, and other drawings can also be obtained according to these drawings without creative labor for the ordinary skilled in the art.

[0018] Figure 1 It is the structural schematic diagram of prior centrifugal pump;

[0019] Figure 2 It is the structural schematic diagram of centrifugal pump of the utility model embodiment;

[0020] Figure 3 It is Figure 2 The schematic diagram of axial magnetic flux motor in centrifugal pump shown in figure 1;

[0021] Figure 4 It is Figure 3 The sectional view along line C-C;

[0022] Figure 5 It is Figure 3 The schematic diagram of driving rotor and permanent magnet in axial magnetic flux motor shown in figure 2;

[0023] Figure 6 It is Figure 3 The perspective view of bearing end cover in axial magnetic flux motor shown in figure 3;

[0024] Figure 7 It is Figure 6 The perspective view of bearing end cover from another angle shown in figure 4;

[0025] Figure 8 It is Figure 2 The schematic diagram of sealing mechanism in centrifugal pump shown in figure 5;

[0026] Figure 9 It is Figure 2 The schematic diagram of exhaust mechanism in centrifugal pump shown in figure 6;

[0027] Figure 10 It is Figure 2 The partial enlarged view of anti-leakage mechanism, pump body and impeller in centrifugal pump shown in figure 7;

[0028] Figure 11 It is Figure 10 The side view of anti-leakage mechanism shown in figure 8. DETAILED DESCRIPTION

[0029] In order for those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0030] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or indirectly on the other element; when an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0031] It should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0032] In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second", etc. can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" or "several" is two or more, unless otherwise explicitly and specifically limited.

[0033] It should be understood that the structures, proportions, sizes, etc. shown in the drawings of the present application are only used to cooperate with the content disclosed in the description, to enable those skilled in the art to understand and read, and are not used to limit the conditions that can be implemented by the present application, and therefore do not have technical significance. Any modification of structure, change of proportion relationship or adjustment of size, which does not affect the effects and purposes that can be achieved by the present application, should still fall within the scope of the technical content disclosed by the present application.

[0034] As shown in Figures 2 to 11 The embodiments of the present application provide a centrifugal pump, specifically a double-suction pump, more specifically a double-drive double-suction pump. In other embodiments, other centrifugal pumps other than double-suction pumps can also be used.

[0035] The centrifugal pump comprises a pump body 2, a pump shaft 3, a sealing mechanism 4, an impeller 5, an axial flux motor 6 (as a driving mechanism), and an exhaust mechanism 7. The pump shaft 3 is rotatably installed on the pump body 2 through the sealing mechanism 4, and a sealed cavity is formed in the pump body 2. The impeller 5 is installed on the pump shaft 3 and located in the sealed cavity, and the axial flux motor 6 is installed at both ends of the pump shaft 3 to form a double driving mechanism (in other embodiments, the axial flux motor 6 can also be installed at only one end of the pump shaft 3). The axial flux motor 6 drives the impeller 5 to rotate through the pump shaft 3, so that the fluid is transported. The axial flux motor is used as the driving mechanism, so that a common base is not needed, the centering needs to be maintained, the bearing box of the pump itself is not needed, the overall structure can be greatly simplified, and the floor area is reduced.

[0036] Compared with the traditional structure, the double-drive double-suction pump adopting the axial flux motor 6 has the following advantages:

[0037] The axial flux motor 6 directly replaces the bearing box of the double-suction pump and is installed at both ends of the double-suction pump, so that a common base is not needed, the centering needs to be maintained, the bearing box of the pump itself is not needed, and the product life cycle cost is greatly reduced;

[0038] The axial flux motor 6 has no cooling fan, and the unit noise is smaller. The double-suction pump structure of the utility model is a coaxial form, the concentricity is better, and the product vibration is smaller;

[0039] The magnetic field generated by the coil of the axial flux motor 6 from inside to outside can all participate in the work process, so that the power density of the axial flux motor is much larger than that of the radial flux motor, and the efficiency is also higher. After the common base, the coupling, the motor coil, the motor heat dissipation and other components are reduced in the embodiment, the weight and the floor area are reduced by more than 50% compared with the traditional structure double-suction pump unit, and the pump house construction cost is also reduced;

[0040] The double-drive axial flux motor is adopted at both ends, and the same structure is adopted for clockwise and counterclockwise, so that the adaptability is better, and the part inventory of the manufacturer is also less;

[0041] The double-drive axial flux motor is adopted at both ends, and the torque is input on both sides at the same time, so that the shaft diameter of the pump shaft 3 can be designed according to half of the maximum torque of the pump, the shaft material can be reduced, the inlet area of the pump impeller 5 is correspondingly increased after the shaft is reduced, and the cavitation performance of the pump is improved;

[0042] The double-drive axial flux motor is adopted, and when the rotating speed of the pump is reduced to below 75%, only one motor can be operated to meet the power requirement of the unit operation, and the unit energy consumption is lower.

[0043] In summary, the centrifugal pump has the characteristics of high operation efficiency, small floor area and convenient installation, and is more suitable for prefabricated pump houses, residential water supply and other fields compared with the traditional structure double-suction pump.

[0044] As Figure 3 , Figure 4 shown, in this embodiment, the two axial flux motors 6 are structurally identical, arranged in mirror image at both ends of the pump shaft 3. Each axial flux motor 6 includes a bearing seat 61, a bearing gland 62, and a drive rotor 63. The drive rotor 63 is mounted on the pump shaft 3 and uniformly arranged with a plurality of permanent magnets 64 (as Figure 5 shown, in this embodiment, there are 12 permanent magnets, embedded in the uniformly arranged through holes of the drive rotor). The bearing gland 62 is installed outside the bearing seat 61 to form a cavity surrounding the drive rotor 63, and the bearing gland 62 and the bearing seat 61 are both uniformly provided with the same number of first winding blocks (not shown) and second winding blocks 69 (the winding of the first winding block and the second winding block extends out of the axial flux motor 6 to connect to the power supply) as the permanent magnets 64. The axial flux motor 6 is formed by the cooperation of the permanent magnets 64 and the first winding blocks and the second winding blocks. The inside of the bearing seat 61 is also provided with a bearing 66 and a bearing end cover 67, and the end of the pump shaft is also provided with a locking nut 68.

[0045] The use of this bearing body component with driving function can reduce the coupling component and reduce the running vibration; it can be used without additional motor, reducing the floor area of the unit, suitable for occasions such as ships and offshore platforms that require equipment size; more suitable for power battery powered environment, convenient for various emergency, mobile facilities and other non-power grid power supply areas.

[0046] In combination with Figure 6 , Figure 7As shown, in this embodiment, the bearing gland 62 is provided with a second cooling water cavity 621, which is sealed by a second water seal plate 622. The second cooling water cavity 621 is connected to a water inlet and a water outlet through a second cooling water cavity interface 623. The inner surface of the bearing gland 62 is provided with a plurality of second protrusions 624, the outer surface of each second protrusion 624 is matched with a corresponding second winding block, and the inner surface is provided with a second inner recess 625 as a part of the second cooling water cavity 621. The bearing seat 61 is provided with a first cooling water cavity 611, which is sealed by a first water seal plate 612. The first cooling water cavity 611 is connected to a water inlet and a water outlet through a first cooling water cavity interface 613. The outer surface of the inner end wall of the bearing seat 61 is provided with a plurality of first protrusions 614, the outer surface of each first protrusion 614 is matched with a corresponding first winding block, and the inner surface is provided with a first inner recess as a part of the first cooling water cavity 611 (the shape and structure of the first protrusion 614 and the first inner recess are similar to those of the second protrusion 624 and the second inner recess 625). The bearing seat 61 and the drive rotor 63 are further provided with a cooling water coil 65, which is adhered to the inner wall of the bearing seat 61 by a heat-conducting adhesive, and is connected to a water inlet and a water outlet through a cooling water coil interface 651. The first cooling water cavity interface 613, the second cooling water cavity interface 623, and the cooling water coil interface 651 are all connected to the inside of the pump body 2 through a third pipeline, and the cooling water is provided by the pump itself. Through the above structure, the bearing body part adopts a multi-region water cooling arrangement, which can effectively reduce the influence of winding heating.

[0047] As shown in the figure, Figure 8 In this embodiment, the sealing mechanism 4 includes a mechanical seal moving ring 41, a mechanical seal stationary ring 42, a packing ring 43, and a packing gland 44 (a half packing gland is used in this embodiment). The mechanical seal moving ring 41 is fixed to the pump shaft 3, the mechanical seal stationary ring 42 is fixed to the pump body 2, and the mechanical seal moving ring 41 and the mechanical seal stationary ring 42 seal the sealing cavity. The outer end of the mechanical seal stationary ring 42 is provided with a receiving groove for accommodating the packing ring 43, and the packing gland 44 can be installed at the end of the receiving groove and press the packing ring 43, so that when the mechanical seal between the mechanical seal moving ring 41 and the mechanical seal stationary ring 42 fails, the packing ring 43 and the packing gland 44 can be installed on the mechanical seal stationary ring 42 to realize packing sealing.

[0048] This scheme can solve the problem that the original mechanical seal structure must be repaired immediately when it is damaged. It does not need to be repaired immediately, can meet the emergency use requirements, and can notify the professional personnel of the equipment manufacturer to replace the mechanical seal while in use. The capital occupation ratio of the packing ring and the half packing gland is less than that of the spare mechanical seal, and the operation difficulty of the packing and the half packing gland is smaller. This scheme can also be used for emergency water supply, ship pumps and other special occasions.

[0049] As shown in the figure, Figure 9As shown, in the embodiment, the exhaust mechanism 7 includes an automatic exhaust valve 71, which communicates the high-pressure area (high-pressure water outlet area) A of the sealed cavity of the pump body 2 with the two low-pressure areas (low-pressure water inlet areas) B. Specifically, the exhaust mechanism further includes a first four-way pipe 72, a first pipe 73 connected to the automatic exhaust valve 71, the high-pressure area exhaust hole of the sealed cavity, and the two low-pressure area exhaust holes of the sealed cavity, respectively, and a check valve 74 provided on the first pipe 73. This scheme can solve the problem that the original automatic exhaust valve only exhausts the accumulated gas in the high-pressure area, and the exhaust holes in the low-pressure area are blocked by a grommet. During installation and debugging, the exhaust needs to be unscrewed with a wrench, which is inconvenient, and the liquid in the pump will be discharged and pollute the surface of the equipment. The purpose of conveniently exhausting the accumulated gas in the pump is achieved, and the check valve effectively prevents the liquid in the high-pressure area from flowing back to the low-pressure area. The first four-way pipe 72 and the high-pressure area exhaust hole of the sealed cavity are further provided with a second four-way pipe 75, which is connected to the mechanical seal through two second pipes 76 for spraying water between the dynamic ring 41 and the static ring 42 of the mechanical seal, thereby playing a role in lubricating, flushing, and cooling the mechanical seal.

[0050] As shown in Figure 10 , Figure 11 As shown in the embodiment, a leakage prevention mechanism is provided between the pump body 2 and the impeller 5 to reduce leakage from the high-pressure water outlet area to the low-pressure water inlet area during pump operation. The leakage prevention mechanism includes a sealing ring 8, which is provided with two threaded holes below the center line, and two screws 9 (hexagonal head screws in the embodiment, with a Teflon coating on the surface) are installed in the threaded holes from the outside to the inside. The pump body 2 is provided with a positioning groove 21 at a position corresponding to the head of the screw 9, which cooperates with the head of the screw 9 to limit the rotation of the sealing ring 8 with the impeller 5 and prevent the screw 21 from coming out of the threaded hole. At the same time, during pump operation, the rotation of the impeller 5 will cause the formation of high-pressure and low-pressure areas in the sealed cavity, and the pressure difference between the high-pressure and low-pressure areas will tightly adhere the sealing ring 8 to the pump body, thereby limiting the axial movement of the sealing ring 8. Compared with the existing elastic cylindrical pin which relies on elastic deformation to form friction, the screw thread is less likely to come out; the existing elastic cylindrical pin is a hollow structure, and the positioning hole drilled through the sealing ring is easy to cause additional leakage. For thin-walled sealing rings, the threaded hole has better sealing performance; the existing elastic cylindrical pin needs to have elastic material to be used, which is limited in corrosive media, while most materials can be processed into hexagonal head screws (normal use, using 316L base material, which can be used in most media); the hexagonal head screw increases the corrosion resistance and insulation by adding a Teflon coating, which can effectively reduce the influence of electrochemical corrosion on the screw and reduce the risk of screw breakage.

[0051] The above description of disclosed embodiments enables one of ordinary skill in the art to make or use the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An exhaust mechanism for a centrifugal pump, the centrifugal pump comprising a pump body, a pump shaft, an impeller, and a drive mechanism; the pump shaft is rotatably mounted on the pump body, forming a sealed cavity inside the pump body; the impeller is mounted on the pump shaft and located within the sealed cavity, and the drive mechanism is mounted at at least one end of the pump shaft, the drive mechanism driving the impeller to rotate via the pump shaft to achieve fluid transport, characterized in that, The exhaust mechanism comprises an automatic exhaust valve, which communicates the high-pressure area of the pump body sealing cavity with the two low-pressure areas.

2. The venting mechanism for a centrifugal pump of claim 1, wherein, The exhaust mechanism comprises a first four-way pipe, which is connected with the automatic exhaust valve, the high-pressure area exhaust hole of the sealing cavity, and a first pipeline connected with the two low-pressure area exhaust holes of the sealing cavity, respectively.

3. The venting mechanism for a centrifugal pump of claim 2, wherein, A check valve is arranged on the first pipeline connected with the two low-pressure area exhaust holes of the sealing cavity.

4. A centrifugal pump characterized by The centrifugal pump comprises a pump body, a pump shaft, an impeller, and a driving mechanism. The pump shaft is rotatably installed on the pump body to form a sealing cavity inside the pump body. The impeller is installed on the pump shaft and located in the sealing cavity. The pump shaft is provided with the driving mechanism at least at one end. The driving mechanism drives the impeller to rotate through the pump shaft to realize the delivery of fluid. The centrifugal pump is provided with the exhaust mechanism as claimed in any one of claims 1 to 3.

5. The centrifugal pump of claim 4, wherein, The centrifugal pump is a double-suction pump. The driving mechanism comprises axial flux motors installed at both ends of the pump shaft to form a double-drive double-suction pump.

6. The centrifugal pump of claim 5, wherein, The axial flux motor comprises a bearing seat, a bearing gland, and a driving rotor. The driving rotor is installed on the pump shaft and uniformly arranged with a plurality of permanent magnets. The bearing gland is installed outside the bearing seat to form a cavity surrounding the driving rotor. The bearing gland and the bearing seat are uniformly provided with the same number of first winding blocks and second winding blocks as the permanent magnets.

7. The centrifugal pump of claim 6, wherein, The bearing seat is provided with a first cooling water cavity, which is sealed by a first water seal plate. The bearing gland is provided with a second cooling water cavity, which is sealed by a second water seal plate. The bearing seat and the driving rotor are further provided with a cooling water coil.

8. The centrifugal pump of claim 7, wherein, The first cooling water cavity realizes water inlet and outlet through a first cooling water cavity interface. The second cooling water cavity realizes water inlet and outlet through a second cooling water cavity interface. The cooling water coil realizes water inlet and outlet through a cooling water coil interface. The first cooling water cavity interface, the second cooling water cavity interface, and the cooling water coil interface are connected with the inside of the pump body through a third pipeline.

9. The centrifugal pump of claim 4, wherein, A sealing mechanism is arranged between the pump body and the pump shaft. The sealing mechanism comprises a mechanical seal dynamic ring, a mechanical seal static ring, a packing ring, and a packing gland. The mechanical seal dynamic ring is fixed on the pump shaft. The mechanical seal static ring is fixed on the pump body. The mechanical seal dynamic ring and the mechanical seal static ring seal the sealing cavity. The mechanical seal static ring is provided with a receiving groove for accommodating the packing ring. The packing gland can be installed at the end of the receiving groove and compress the packing ring, so that when the mechanical seal between the mechanical seal dynamic ring and the mechanical seal static ring fails, the packing ring and the packing gland can be installed on the mechanical seal static ring to realize packing sealing.

10. The centrifugal pump of claim 9, wherein, A second four-way pipe is further arranged between the first four-way pipe and the high-pressure area exhaust hole of the sealing cavity. The second four-way pipe is connected with the mechanical seal through two second pipelines to spray water between the mechanical seal dynamic ring and the mechanical seal static ring.

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