Balance pump for balancing axial force of impeller

Abstract

The balance pump used for balancing the axial force of the impeller comprises the impeller, a pump shell and a rotating shaft, the impeller is connected with the rotating shaft, and the impeller is located in the pump shell; the impeller comprises an impeller hub and an impeller body, the impeller body is connected with the impeller hub, an impeller channel is formed in the impeller body, the end, close to the impeller hub, of the impeller channel is called as an impeller inlet, and the end, away from the impeller inlet, of the impeller body is called as an impeller back face. A pressure balance hole is formed in the impeller body, so that the pressure balance hole is communicated with an impeller inlet and a cavity in the back face of the impeller. The balance pump has the effects of improving the production cost of the balance pump and reducing the occupied space of the balance pump.

Description

Technical Field

[0001] The present application relates to the field of pump technology, and in particular, to a balancing pump for balancing the axial force of an impeller. Background Art

[0002] A pump converts kinetic energy into pressure through an impeller, causing a negative pressure to form in the exact middle of the impeller. External fluid enters the balancing pump through the impeller inlet with the negative pressure in the exact middle of the impeller and is radially ejected through the impeller channel. For a multi-stage centrifugal pump, the high-pressure liquid ejected by the impeller is gathered through the pump casing part, guided to the next-stage impeller and decelerated, and the kinetic energy of the liquid is converted into pressure energy.

[0003] In the prior art, since the pressure at the outlet end is greater than the pressure at the inlet end when the impeller is running, an axial force from the rear to the front is generated on the rotor. The axial force of the impeller can be balanced by designing a thrust balancing device from the front to the rear. However, adding a thrust balancing device on the one hand increases the volume of the balancing pump, and on the other hand increases the production cost.

[0004] In summary, the balancing pump in the prior art has a large volume and a high production cost, so there is room for further improvement. Summary of the Utility Model

[0005] In view of this, the present application provides a balancing pump for balancing the axial force of an impeller, which can balance the axial force generated by the rotation of the impeller, so that the balancing pump for balancing the axial force of the impeller occupies a small space and has a low production cost.

[0006] In order to improve the production cost of the balancing pump and reduce the occupied space of the balancing pump, the present application provides a balancing pump for balancing the axial force of an impeller.

[0007] The balancing pump for balancing the axial force of an impeller provided by the present application adopts the following technical solution:

[0008] A balancing pump for balancing the axial force of an impeller includes an impeller, a pump casing and a rotating shaft. The impeller is connected to the rotating shaft and is located inside the pump casing. The impeller includes an impeller hub and an impeller body. The impeller body is connected to the impeller hub. An impeller channel is formed on the impeller body. One end of the impeller channel near the impeller hub is called the impeller inlet, and one end of the impeller body away from the impeller inlet is called the impeller back surface. A pressure balancing hole is formed on the impeller body, so that the pressure balancing hole communicates the impeller inlet with the cavity at the impeller back surface.

[0009] By adopting the above technical solution, since the pump casing converges the high-pressure liquid thrown out by the impeller, guides it to the next-stage impeller and decelerates it, converting the kinetic energy of the liquid into pressure energy, the balance pump converges the fluid at the impeller outlet to the back of the impeller and the inlet of the next impeller. The pressure balance hole enables part of the liquid at the impeller inlet to pass through the pressure balance hole and guide it to the back of the impeller inlet. By opening the pressure balance hole at the impeller inlet, the pressure difference between both ends of the impeller is balanced, thereby reducing the axial load of the pump, further reducing the rotational friction resistance between the impeller inlet and the pump casing, improving the working efficiency of the pump, and prolonging the service life of the pump.

[0010] Preferably, one end of the impeller passage away from the impeller hub is the impeller outlet. A balance gap is formed between the impeller and the pump casing at the impeller outlet, and the balance gap is used to balance the axial load of the impeller.

[0011] By adopting the above technical solution, the impeller rotates driven by the rotating shaft, causing a negative pressure area to be formed in the middle of the impeller, sucking in the external fluid from the impeller inlet and throwing it out from the impeller outlet, generating a pressure difference between one end of the impeller near the impeller inlet and the end of the impeller away from the impeller inlet. As a result, an axial load will be generated during the operation of the impeller. The pump casing converges the high-pressure liquid thrown out by the impeller, guides it to the next-stage impeller and decelerates it, converting the kinetic energy of the liquid into pressure energy (it can also be guided to the pump outlet). By opening the pressure balance hole at the impeller inlet, the pressure difference between both ends of the impeller is balanced, thereby reducing the axial load of the pump, further reducing the rotational friction resistance between the impeller inlet and the pump casing, improving the working efficiency of the pump, and prolonging the service life of the pump. Moreover, the balance gap formed between the impeller and the pump casing enables part of the fluid to impact downward after reaching the impeller outlet, thereby balancing the negative pressure impact of the fluid at the impeller inlet, reversely balancing the axial load of the impeller, reducing the rotational friction resistance between the impeller inlet and the pump casing. And through the settings of the pressure balance hole and the balance gap, the axial load of the balance pump can be optimized, making the balance pump with balanced axial load have a lower production cost and occupy less space.

[0012] Preferably, the flow rate of the balance gap is greater than the flow rate of the pressure balance hole.

[0013] By adopting the above technical solution, the axial impact generated by the pressure balance hole is less than the axial impact generated by the balance gap, so that the balance gap can not only balance the axial impact in the direction of the pressure balance hole, but also balance the axial load generated during the operation of the impeller. As a result, the overall axial load of the balance pump is relatively low, further reducing the rotational friction resistance between the impeller inlet and the pump casing, improving the working efficiency of the balance pump, and prolonging the service life of the balance pump.

[0014] Preferably, an impeller protrusion is provided at one end of the impeller body away from the impeller inlet. A floating ring is provided between the impeller and the pump casing. The floating ring floats radially. The floating ring is connected to the pump casing, and the projection of the impeller protrusion and the floating ring on the vertical plane partially overlaps. A back plate is provided on the floating ring, so that the floating ring floats radially on the back plate, and the back plate has a back plate channel.

[0015] By adopting the above technical solution, the floating ring is radially and floatingly installed between the impeller and the pump casing, so that the floating ring can not only float radially between the impeller and the pump casing, but also be relatively sealed between the impeller protrusion and the impeller hub. This not only forms a negative pressure area on the back of the impeller that communicates with the pressure balance hole at the impeller inlet, but also reduces the fitting clearance between the impeller hub and the impeller protrusion, improves the volumetric efficiency of the balanced pump, reduces the overall concentricity dimension control requirements of the balanced pump, reduces the production cost of the balanced pump, and on the one hand, the back plate tightens the position of the floating ring between the impeller and the pump casing, and on the other hand, further guides the fluid into the next impeller or the pump outlet through the back plate channel.

[0016] Preferably, when the end of the impeller hub is higher than the end of the impeller protrusion, the floating ring includes a first ring body portion for clearance sealing with the impeller hub, a second ring body portion for clearance sealing with the impeller protrusion, and a second protrusion portion for connecting with the pump casing. The first ring body portion is connected to the second ring body portion, and the second protrusion portion is connected to the second ring body portion. When the end of the impeller hub is not higher than the end of the impeller protrusion, the floating ring includes a first ring body portion for connecting with the rotating shaft, a second ring body portion for clearance sealing with the impeller protrusion, and a second protrusion portion for connecting with the pump casing. The first ring body portion is connected to the second ring body portion, and the second protrusion portion is connected to the second ring body portion.

[0017] By adopting the above technical solution, the first ring body portion is connected to the second ring body portion, so that the first ring body portion has a clearance fit with the impeller hub or the rotating shaft, and the second ring body portion has a clearance fit with the impeller protrusion. Furthermore, the floating ring can reduce the fitting clearance between the impeller hub and the impeller protrusion, improve the volumetric efficiency of the balanced pump, reduce the overall concentricity dimension control requirements of the balanced pump, reduce the production cost of the balanced pump, and the floating ring is connected to the pump casing through the second protrusion portion, so that the floating ring is limited in position between the pump casing and the impeller.

[0018] Preferably, the floating ring includes a first ring body portion for connecting with the rotating shaft, a second ring body portion for clearance sealing with the impeller protrusion, and a second protrusion portion for connecting with the pump casing. The first ring body portion is connected to the second ring body portion, and the second protrusion portion is connected to the second ring body portion.

[0019] By adopting the above technical solution, the first ring body is connected to the second ring body. Since the first ring body is connected to the rotating shaft and the second ring body is connected to the impeller protrusion, the floating ring can reduce the fitting clearance between the rotating shaft and the impeller protrusion, thereby improving the volumetric efficiency of the balanced pump, reducing the overall concentricity dimension control requirements of the balanced pump, and reducing the production cost of the balanced pump. The floating ring is connected to the pump casing through the second protrusion, so that the floating ring is limited at a position between the pump casing and the impeller.

[0020] Preferably, the floating ring includes a first ring body portion for connecting to an impeller hub or a rotating shaft, a second ring body portion for connecting to an impeller protrusion, and a second protrusion portion for connecting to a pump casing, wherein the first ring body portion is connected to the second ring body portion, and the second ring body portion is connected to the second protrusion portion.

[0021] By adopting the above technical solution, the floating ring is connected to the impeller hub or the rotating shaft through the first ring body, and is connected to the impeller protrusion through the second ring body, so that the floating ring covers the space between the impeller protrusion and the impeller hub, so that the impeller protrusion and the impeller hub are relatively sealed. The floating ring is connected to the pump casing through the second protrusion, so that the floating ring can float radially between the pump casing and the impeller.

[0022] Preferably, a back plate groove is provided on the back plate, and a second protrusion is provided on the floating ring, and the second protrusion cooperates with the back plate groove.

[0023] By adopting the above technical solution, the back plate and the floating ring are tightly connected, so that the back plate further reduces the fitting clearance between the impeller hub and the impeller protrusion, thereby improving the volumetric efficiency of the balancing pump, reducing the overall concentricity dimension control requirements of the balancing pump, and reducing the production cost of the balancing pump.

[0024] Preferably, the pump casing includes a guide plate cover, an outer shell part and a guide vane part, the guide vane part is connected to the outer shell part, and the guide plate is located at both ends of the outer shell part, so that the guide plate and the outer shell part form a seal for the impeller, and the guide vane part gathers the high-pressure liquid thrown out by the impeller and guides it to the next impeller inlet or the outlet of the balancing pump.

[0025] By adopting the above technical solution, the guide vane part is integrally formed in the outer shell part, the guide plate cover is installed at both ends of the outer shell part, and the impeller is also installed in the outer shell part, so that the external fluid is sucked in from the impeller inlet and thrown out from the impeller outlet. At this time, the fluid is located in the outer shell part. After the fluid is thrown out from the impeller outlet, it flows into the back of the impeller through the guide vane part integrally formed with the outer shell, and then the fluid enters the next impeller inlet or the fluid flows out of the balancing pump outlet.

[0026] Preferably, a first protrusion is provided at the inlet of the impeller. The pump housing includes a guide disk cover, and an impeller port ring is provided on the guide disk cover. The first protrusion is matched with the impeller port ring.

[0027] By adopting the above technical solution, the connection between the guide disk cover and the first protrusion is tightened through the impeller port ring, which is convenient for balancing the stable negative pressure generated by the pump, and then stably sucking the fluid.

[0028] In summary, the present application includes at least one of the following beneficial technical effects:

[0029] 1. Since the pump housing converges the high-pressure liquid thrown out by the impeller, guides it to the next-stage impeller and decelerates it, converting the kinetic energy of the liquid into pressure energy, enabling the balancing pump to converge the fluid at the outlet of the impeller with the back of the impeller and the inlet of the next impeller. The pressure balance hole allows a part of the liquid at the inlet of the impeller to pass through the pressure balance hole and be guided to the back of the impeller inlet. By opening the pressure balance hole at the inlet of the impeller, the pressure difference between the two ends of the impeller is balanced, thereby reducing the axial load of the pump, and further reducing the rotational friction resistance between the impeller inlet and the pump housing, thereby improving the working efficiency of the pump and extending the service life of the pump;

[0030] 2. The impeller rotates under the drive of the rotating shaft, forming a negative pressure area in the middle of the impeller, sucking the external fluid from the impeller inlet and throwing it out from the impeller outlet, generating a pressure difference between one end of the impeller near the impeller inlet and the end of the impeller far from the impeller inlet. As a result, the impeller will generate an axial load during operation. The pump housing converges the high-pressure liquid thrown out by the impeller, guides it to the next-stage impeller and decelerates it, converting the kinetic energy of the liquid into pressure energy (it can also be guided to the pump outlet). By opening the pressure balance hole at the inlet of the impeller, the pressure difference between the two ends of the impeller is balanced, thereby reducing the axial load of the pump, and further reducing the rotational friction resistance between the impeller inlet and the pump housing, thereby improving the working efficiency of the pump and extending the service life of the pump. Moreover, the balance gap formed between the impeller and the pump housing allows part of the fluid to impact downward after reaching the impeller outlet, thereby balancing the negative pressure impact of the fluid at the impeller inlet, thereby reversely balancing the axial load of the impeller, reducing the rotational friction resistance between the impeller inlet and the pump housing, and by setting the pressure balance hole and the balance gap, the axial load of the balancing pump can be optimized, making the balancing pump with balanced axial load have a lower production cost and occupy less space;

[0031] 3. It is radially and floatingly installed on the impeller and the pump casing through a floating ring, enabling the floating ring to not only float radially between the impeller and the pump casing but also be relatively sealed between the impeller protrusion and the impeller hub. This not only forms a negative pressure area on the back of the impeller that communicates with the pressure balance hole at the impeller inlet but also reduces the fitting clearance between the impeller hub and the impeller protrusion, improving the volumetric efficiency of the balanced pump, reducing the requirement for controlling the overall concentricity dimension of the balanced pump, lowering the production cost of the balanced pump, and on the one hand, the back plate tightens the position of the floating ring between the impeller and the pump casing, and on the other hand, further guides the fluid into the next impeller or the pump outlet through the back plate channel. Description of the Drawings

[0032] Figure 1 It is a cross-sectional view of the balanced pump in this embodiment;

[0033] Figure 2 It is a structural schematic diagram of the impeller in this embodiment;

[0034] Figure 3 It is a structural schematic diagram of the housing part and the guide vane part in this embodiment;

[0035] Figure 4 It is a structural schematic diagram of the floating ring in this embodiment;

[0036] Figure 5 It is a structural schematic diagram of the back plate in this embodiment;

[0037] Figure 6 It is a cross-sectional view of the balanced pump in this embodiment;

[0038] Figure 7 It is a cross-sectional view of the balanced pump in this embodiment.

[0039] Reference Numerals: 1. Impeller; 2. Pump Casing; 3. Rotating Shaft; 4. Impeller Inlet; 5. Impeller Outlet; 6. Pressure Balance Hole; 7. Balance Gap; 8. Impeller Hub; 9. Impeller Body; 10. Impeller Channel; 11. Impeller Protrusion; 12. Floating Ring; 13. Back Plate; 14. Back Plate Channel; 15. Flow Guide Disc Cover; 16. Housing Part; 17. Guide Vane Part; 18. First Ring Body Part; 19. Second Ring Body Part; 20. Guide Vane Axial Protrusion; 21. Second Protrusion Part; 22. First Protrusion; 23. Impeller Mouth Ring; 24. Second Notch; 25. Third Notch; 26. First Flow Guide Disc Cover; 27. Second Flow Guide Disc Cover; 28. Back Plate Groove; 29. Floating Ring Protrusion. Detailed Description of the Embodiment

[0040] The following is a further detailed description of this application in combination with the attached Figures 1-7 drawings.

[0041] The embodiment of this application discloses a balanced pump for balancing the axial force of an impeller.

[0042] Reference Figure 1 , including an impeller 1, a pump casing 2 and a rotating shaft 3. The rotating shaft 3 is a hexagonal rotating shaft 3. The impeller 1 is connected to the rotating shaft 3 so that the rotation of the rotating shaft 3 can drive the rotation of the impeller 1. The pump casing 2 is connected to the impeller 1. On the one hand, the pump casing 2 seals the impeller 1 relatively. On the other hand, the pump casing 2 can gather the high-pressure liquid thrown out by the impeller 1 and guide it to the outlet of the balance pump.

[0043] Refer to Figure 1 and Figure 2 , the impeller 1 includes an impeller hub 8 for cooperating with the rotating shaft 3 and an impeller body 9. The impeller hub 8 and the impeller body 9 are integrally formed. An impeller passage 10 is provided on the impeller body 9. One end of the impeller passage 10 near the impeller hub 8 is called the impeller inlet 4. A first protrusion 22 is integrally formed on the lower side of the impeller 1 at the impeller inlet 4. The end of the impeller passage 10 far from the impeller hub 8 is the impeller outlet 5. So that the impeller 1 rotates under the drive of the rotating shaft 3, a negative pressure area is formed at the impeller inlet 4 in the middle of the impeller 1. The external fluid is sucked in from the impeller inlet 4. The external fluid flows radially through the impeller passage 10 and is thrown out from the impeller outlet 5. The upper end of the impeller 1 far from the impeller inlet 4 is called the impeller back surface. An impeller protrusion 11 is integrally formed on the impeller back surface. So that the impeller protrusion 11 is arranged around the impeller hub 8. There is a gap between the impeller 1 at the impeller protrusion 11 and the impeller hub 8. A pressure balance hole 6 is axially provided in the impeller 1 at the gap. So that the pressure balance hole 6 communicates the impeller inlet 4 with the gap. In this way, the pressure difference between the two ends of the impeller 1 at the impeller inlet 4 and the gap is balanced. In this way, the axial load of the balance pump is reduced. Furthermore, the rotational friction resistance between the impeller inlet 4 and the pump casing 2 is reduced. In this way, the working efficiency of the pump is improved and the service life of the balance pump is extended.

[0044] Refer to Figure 1 and Figure 3, the pump housing 2 includes a deflector disc cover 15, a housing part 16 and a diffuser part 17. The deflector disc cover 15 is annular. A first notch is formed at the edge of the proximal part of the deflector disc cover 15. The first notch is also called the impeller mouth ring 23, and the inner wall of the first notch is inclined. A second notch 24 is formed on the upper side of the edge of the deflector disc cover 15 away from the center, and a third notch 25 is formed on the lower side of the edge of the deflector disc cover 15 away from the center. The deflector disc cover 15 can be divided into a first deflector disc cover 26 and a second deflector disc cover 27. The first deflector disc is connected to the cylindrical housing part 16 through the second notch 24, so that the first deflector disc is hermetically connected to the housing part 16. The first deflector disc is connected to the impeller 1 through the first notch, so that the first protrusion 22 of the impeller 1 is located on the first notch. The diffuser part 17 is integrally formed on the upper part of the housing part 16. A connection hole is formed in the center of the diffuser part 17. A diffuser shaft protrusion 20 is integrally formed inside the connection hole of the diffuser part 17. The diffuser part 17 is matched with the impeller hub 8 through the connection hole, so that the impeller 1 is located between the first deflector disc cover 26 and the diffuser part 17, so that the pump housing 2 seals the impeller 1, so that the high-pressure liquid thrown out by the impeller 1 is converged to the center of the upper end of the diffuser part 17 through the housing part 16 and the diffuser part 17, which is convenient for liquid export to balance the pump outlet. The second deflector disc cover 27 is connected to the upper end of the housing part 16 through the third notch 25 on its lower side.

[0045] Reference Figure 1 and Figure 4 , a floating ring 12 is provided between the impeller 1 and the pump housing 2. The floating ring 12 includes a first ring body part 18, a second ring body part 19 and a second protrusion part 21. The first ring body part 18, the second ring body part 19 and the second protrusion part 21 are integrally formed. The end of the impeller hub 8 is higher than the end of the impeller protrusion 11, so that the inner diameter of the first ring body part 18 is in clearance seal with the outer diameter of the impeller hub 8, and the inner diameter of the second ring body part 19 is in clearance seal with the impeller protrusion 11, so that the impeller protrusion 11 and the floating ring 12 partially overlap in the projection on the vertical plane. The projection on the vertical plane is the projection onto the horizontal plane along the plumb line. The second protrusion part 21 is located on the diffuser shaft protrusion 20, so that the second protrusion part 21 is limited by the diffuser part 17, so that the floating ring 12 is radially floatingly arranged between the impeller 1 and the pump housing 2, and the floating ring 12 is relatively hermetically arranged at the position between the impeller protrusion 11 and the impeller hub 8. It not only makes the floating ring 12 form a negative pressure area on the back of the impeller that is communicated with the pressure balance hole 6 at the impeller inlet 4, but also reduces the mating clearance between the impeller hub 8 and the impeller protrusion 11, improves the volumetric efficiency of the balance pump, and reduces the control requirements for the overall concentricity dimension of the balance pump, reducing the production cost of the balance pump.

[0046] Further, in this embodiment, when the end of the impeller hub 8 is not higher than the end of the impeller protrusion 11, the floating ring 12 includes a first ring body portion 18, a second ring body portion 19, and a second protrusion portion 21. The first ring body portion 18, the second ring body portion 19, and the second protrusion portion 21 are integrally formed. The floating ring is in clearance seal with the rotating shaft through the first ring body portion. The inner diameter of the second ring body portion 19 is in clearance seal with the impeller protrusion 11. The second protrusion portion 21 is located on the guide vane shaft protrusion 20, so that the second protrusion portion 21 is limited by the guide vane portion 17.

[0047] Further, in this embodiment, the floating ring 12 can also be in other forms. For example, the floating ring 12 includes a first ring body portion 18 for clearance sealing the impeller hub 8 or the rotating shaft 3, a second ring body portion 19 for clearance sealing the impeller protrusion 11, and a second protrusion portion 21 for connecting with the pump casing 2. The first ring body portion 18, the second ring body portion 19, and the second protrusion portion 21 are integrally formed. The floating ring 12 is sleeved on the impeller hub 8 through the first ring body portion 18, and the second ring body portion 19 is sleeved on the impeller protrusion 11. Thus, the space between the impeller hub 8 and the impeller protrusion 11 is covered by the first ring body portion 18 of the floating ring 12, and the second protrusion portion 21 is located on the guide vane shaft protrusion 20.

[0048] Further, in this embodiment, referring to Figure 1 and Figure 5 , a back plate 13 is provided on the floating ring 12. A back plate channel 14 is provided at the upper end of the back plate 13, and a back plate groove 28 is formed at the lower end of the back plate 13. Floating ring protrusions 29 are uniformly provided on the second protrusion portion 21. The floating ring protrusions 29 cooperate with the back plate groove 28, so that on the one hand, the back plate 13 tightens the position of the floating ring 12 between the impeller 1 and the pump casing 2, and on the other hand, fluid is further guided into the next impeller 1 or the outlet of the pump is balanced through the back plate channel 14.

[0049] Further, in this embodiment, the impeller 1 does not contact the housing portion 16 near the impeller outlet 5, so that a balance gap 7 is formed between the impeller outlet 5 and the first deflector cover 26. Due to the balance gap 7, part of the fluid discharged from the impeller outlet 5 is squeezed downward, so that after the fluid reaches the impeller outlet 5, part of it impacts downward, thereby balancing the negative pressure impact of the fluid at the impeller inlet 4, balancing the axial load of the impeller 1 in the reverse direction, reducing the rotational friction resistance between the impeller inlet 4 and the pump casing 2, and optimizing the balance of the axial load of the pump through the setting of the pressure balance hole 6 and the balance gap 7, so that the production cost of the axially load-balanced pump is relatively low and the occupied space is also low.

[0050] Further, in this embodiment, the flow rate of the balance gap 7 is greater than that of the pressure balance hole 6, so that the axial impact generated by the pressure balance hole 6 is less than the axial impact generated by the balance gap 7. As a result, the balance gap 7 can not only balance the axial impact in the direction of the pressure balance hole 6, but also balance the axial load generated by the impeller 1 during operation. Furthermore, the overall axial load of the pump is relatively low, thereby reducing the rotational friction resistance between the impeller inlet 4 and the pump casing 2, improving the working efficiency of the pump, and extending the service life of the pump.

[0051] Further, in this embodiment, with reference to Figure 6 and Figure 7 , the axial force balanced pumps of the impeller 1 can also be connected in multiple stages to each other, so that the rotation of the rotating shaft 3 in the axial force balanced pump of the impeller 1 can drive the impeller 1 to rotate. The pump casing 2 is connected to the impeller 1. On the one hand, the pump casing 2 seals the impeller 1 relatively, and on the other hand, the pump casing 2 can gather the high-pressure liquid thrown out by the impeller 1, guide it to the next axial force balanced pump of the impeller 1 and decelerate it, so as to convert the liquid kinetic energy of the previous axial force balanced pump of the impeller 1 into the pressure energy of the next axial force balanced pump of the impeller 1, and different requirements for changing the head of the axial force balanced pump of the impeller 1 are achieved through multiple axial force balanced pumps of the impeller 1, making the axial force balanced pump of the impeller 1 have a wide application range.

[0052] Further, in this embodiment, the pump casing 2 can also be connected to the rotating shaft 3, as long as the pump casing 2 can seal the impeller 1 relatively, so that the liquid can enter the impeller 1, and after gathering through the pump casing 2, it can be led out from the other end of the pump casing 2.

[0053] The above are all the preferred embodiments of this application, and the protection scope of this application is not limited accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. A balance pump for balancing the axial force of an impeller, characterized in that: It includes an impeller (1), a pump casing (2) and a rotating shaft (3). The impeller (1) is connected to the rotating shaft (3), and the impeller (1) is located inside the pump casing (2). The impeller (1) includes an impeller hub (8) and an impeller body (9). The impeller body (9) is connected to the impeller hub (8). An impeller passage (10) is formed on the impeller body (9). One end of the impeller passage (10) near the impeller hub (8) is called the impeller inlet (4), and one end of the impeller body (9) away from the impeller inlet (4) is called the impeller back surface. A pressure balance hole (6) is formed on the impeller body (9) so that the pressure balance hole (6) communicates the impeller inlet (4) with the cavity at the impeller back surface.

2. The balance pump according to claim 1, wherein: One end of the impeller passage (10) away from the impeller hub (8) is the impeller outlet (5). A balance gap (7) is formed between the impeller (1) and the pump casing (2) at the impeller outlet (5). The balance gap (7) is used to balance the axial load of the impeller (1).

3. The balanced pump according to claim 2, characterized in that: The flow rate of the balance gap (7) is greater than that of the pressure balance hole (6).

4. The balanced pump according to claim 2, wherein: An impeller protrusion (11) is provided at one end of the impeller body (9) away from the impeller inlet (4). A floating ring (12) is provided between the impeller (1) and the pump casing (2). The floating ring (12) floats radially. The floating ring (12) is connected to the pump casing (2), and a part of the projection of the impeller protrusion (11) and the floating ring (12) on the vertical plane overlaps. A back plate (13) is provided on the floating ring (12) so that the floating ring (12) floats radially on the back plate (13), and the back plate (13) has a back plate passage (14).

5. The balance pump according to claim 4, wherein: When the end of the impeller hub (8) is higher than the end of the impeller protrusion (11), the floating ring (12) includes a first ring body part (18) for clearance sealing with the impeller hub (8), a second ring body part (19) for clearance sealing with the impeller protrusion (11), and a second protrusion part (21) for connection with the pump casing (2). The first ring body part (18) is connected to the second ring body part (19), and the second protrusion part (21) is connected to the second ring body part (19). When the end of the impeller hub (8) is not higher than the end of the impeller protrusion (11), the floating ring (12) includes a first ring body part (18) for connection with the rotating shaft (3), a second ring body part (19) for clearance sealing with the impeller protrusion (11), and a second protrusion part (21) for connection with the pump casing (2). The first ring body part (18) is connected to the second ring body part (19), and the second protrusion part (21) is connected to the second ring body part (19).

6. The balanced pump according to claim 4, characterized in that: The floating ring (12) includes a first ring body part (18) for connecting with the rotating shaft (3), a second ring body part (19) for clearance sealing with the impeller protrusion (11), and a second protrusion part (21) for connecting with the pump casing (2). The first ring body part (18) is connected to the second ring body part (19), and the second protrusion part (21) is connected to the second ring body part (19).

7. The balanced pump according to claim 4, characterized in that: The floating ring (12) includes a first ring body part (18) for connecting with the impeller hub (8) or the rotating shaft (3), a second ring body part (19) for connecting with the impeller protrusion (11), and a second protrusion part (21) for connecting with the pump casing (2). The first ring body part (18) is connected to the second ring body part (19), and the second ring body part (19) is connected to the second protrusion part (21).

8. The balanced pump according to claim 4, wherein: A backplate groove (28) is formed in the backplate (13), and a second protrusion part (21) is provided on the floating ring (12). The second protrusion part (21) is engaged with the backplate groove (28).

9. The balanced pump according to claim 1, wherein: The pump casing (2) includes a flow guide disc cover (15), a housing part (16), and a guide vane part (17). The guide vane part (17) is connected to the housing part (16). The flow guide disc cover (15) is located at both ends of the housing part (16), so that the flow guide disc cover (15) and the housing part (16) form a seal for the impeller (1), and the guide vane part (17) converges the high-pressure liquid discharged by the impeller (1) and guides it to the next impeller inlet (4) or balances the pump outlet.

10. The balanced pump according to claim 1, wherein: A first protrusion (22) is provided at the impeller inlet (4). The pump casing (2) includes a flow guide disc cover (15), and an impeller mouth ring (23) is provided on the flow guide disc cover (15). The first protrusion (22) is engaged with the impeller mouth ring (23).

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