An adaptive axial force balance auxiliary device for a leak-free centrifugal pump

Abstract

The present invention relates to the technical field of centrifugal pumps, and discloses an adaptive axial force balance auxiliary device for a leak-free centrifugal pump, which is arranged between the impeller and the pump cover of the leak-free centrifugal pump. The device comprises a wear-resistant ring and a balance throttle ring. The center of the wear-resistant ring is sleeved on the pump shaft of the centrifugal pump. The wear-resistant ring is connected to the impeller through a first countersunk head bolt. The balance throttle ring is located on the right side of the wear-resistant ring. The center of the balance throttle ring is sleeved on the pump shaft of the centrifugal pump. The pump cover is provided with an annular groove, and both the wear-resistant ring and the balance throttle ring are embedded in the annular groove. The balance throttle ring is fixed on the pump cover through a second countersunk head bolt. The structure of the present invention is simple, the manufacturing cost is low, and the balance effect is good. It can enable the circulating liquid in the leak-free centrifugal pump to work under the minimum allowable internal reflux flow rate, reducing the internal reflux in the pump. Therefore, the occurrence of potential failures of the leak-free centrifugal pump is reduced, and the working efficiency of the centrifugal pump is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of centrifugal pumps, and particularly relates to an adaptive axial force balance auxiliary device for a leak-free centrifugal pump. Background Art

[0002] For current leak-free centrifugal pumps, such as canned pumps, magnetic pumps, etc., the axial force balance systems generally adopt schemes such as opening balance holes in the impeller, adding balance wheels, using balance bearings, symmetrically arranging the impellers, or combining the above schemes. Although the above axial force balance schemes for centrifugal pumps are relatively mature, there have always been disadvantages such as poor cavitation resistance (pumping out) ability, large internal reflux in the pump, affecting the working efficiency, and the equipment state being greatly affected by the flow rate. Once encountering a flow instability condition, in a very short time under the action of huge axial force and vibration, the sliding bearings and thrust bearings of the equipment will be shattered, causing serious damage to the equipment and greatly increasing the maintenance cost. Summary of the Invention

[0003] The purpose of the present invention is to overcome the disadvantages existing in the prior art and provide an adaptive axial force balance auxiliary device for a leak-free centrifugal pump.

[0004] To achieve the above purpose, the technical solution of the present invention is: an adaptive axial force balance auxiliary device for a leak-free centrifugal pump, which is arranged between the impeller and the pump cover of the leak-free centrifugal pump, and is characterized in that: it includes a wear-resistant ring and a balance throttle ring. The center of the wear-resistant ring is sleeved on the pump shaft of the centrifugal pump. The wear-resistant ring is connected to the impeller through a first countersunk bolt. A clamping groove is provided on the left side of the wear-resistant ring, and the bottom surface of the impeller is clamped in the clamping groove. A diversion hole is provided on the wear-resistant ring, and the diversion hole communicates with the balance hole of the impeller. The balance throttle ring is located on the right side of the wear-resistant ring. The center of the balance throttle ring is sleeved on the pump shaft of the centrifugal pump. The pump cover is provided with an annular groove, and both the wear-resistant ring and the balance throttle ring are embedded in the annular groove. The balance throttle ring is fixed on the pump cover through a second countersunk bolt. The gap between the wear-resistant ring and the balance throttle ring is less than 0.05 mm.

[0005] Further; a plurality of annular throttle grooves are provided on the side of the balance throttle ring close to the wear-resistant ring.

[0006] Further; a first sealing gasket is provided between the wear-resistant ring and the bottom surface of the impeller, and a through hole communicating with the balance hole is provided on the first sealing gasket.

[0007] Further; a second sealing gasket is provided between the balance throttle ring and the bottom of the annular groove.

[0008] Advantages of the Present Invention

[0009] The present invention has a simple structure, low manufacturing cost, good balancing effect, and can make the circulating fluid in the leak-free centrifugal pump work at the minimum allowable internal reflux flow, thereby reducing the internal reflux of the pump, thereby reducing the occurrence of potential failures of the leak-free centrifugal pump and improving the working efficiency of the centrifugal pump.

[0010] During the axial force balancing process, the present invention can make the axial movement of the impeller less than 0.2 mm, while the axial movement of the existing leakage-free centrifugal pump can reach about 2 mm. Therefore, the present invention can greatly reduce the axial movement of the leakage-free centrifugal pump during cavitation or vacuuming, improve the cavitation resistance or vacuuming ability of the leakage-free centrifugal pump, and effectively protect the operation of the leakage-free centrifugal pump.

[0011] The invention is easy to install and use, and can be installed when the centrifugal pump is manufactured, or installed after the centrifugal pump is finished. It can even be used as a maintenance component for compensatory repair after the centrifugal pump is slightly damaged, so as to achieve a longer equipment operation cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a split diagram of the present invention;

[0013] Figure 2 It is a schematic diagram of the structure after assembly of the present invention;

[0014] Figure 3 It is a schematic diagram of the balanced throttling ring structure.

[0015] In the figure: 1, balancing hole; 2, impeller front cover plate; 3, impeller rear cover plate; 4, impeller balancing throttle ring; 5, first sealing gasket; 6, wear-resistant ring; 7, first countersunk bolt; 8, balancing throttle ring; 9, balancing sealing ring groove; 10, pump cover; 11, impeller; 12, impeller balancing chamber cover plate; 13, balancing chamber; 14, second sealing gasket; 15, second countersunk bolt; 16, guide hole; 17, slot; 18, annular groove; 19, pump shaft; 20, annular throttle groove. DETAILED DESCRIPTION

[0016] Example:

[0017] like Figure 1 and Figure 3As shown in the figure, an adaptive axial force balance auxiliary device for a leak-free centrifugal pump is provided between the impeller 11 and the pump cover 10 of the leak-free centrifugal pump, and includes a wear-resistant ring 6 and a balance throttle ring 8. The center of the wear-resistant ring 6 is sleeved on the pump shaft 19 of the centrifugal pump. The wear-resistant ring 6 is fixedly connected to the impeller 11 through a first countersunk bolt 7 and rotates with the pump shaft 19. A clamping groove 17 is provided on the left side of the wear-resistant ring 6, and the bottom surface of the impeller 11 is clamped in the clamping groove 17. A diversion hole 16 is provided on the wear-resistant ring 6, and the diversion hole 16 communicates with the balance hole 1 of the impeller 11. The balance throttle ring 8 is located on the right side of the wear-resistant ring 6. The center of the balance throttle ring 8 is sleeved on the pump shaft 19. The pump cover 10 is provided with an annular groove 18. The wear-resistant ring 6 and the balance throttle ring 8 are both embedded in the annular groove 18. The balance throttle ring 8 is fixed on the pump cover 10 through a second countersunk bolt 15. The balance throttle ring 8 does not rotate with the pump shaft 19. The gap between the wear-resistant ring 6 and the balance throttle ring 8 is less than 0.05 mm.

[0018] Preferably in this embodiment, a first sealing gasket 5 is provided between the bottom surface of the wear-resistant ring 6 and the impeller 11. A through hole communicating with the balance hole 1 is provided on the first sealing gasket 5. The first countersunk bolt 7 passes through the wear-resistant ring 6 and the first sealing gasket 5 to connect the impeller 11.

[0019] Preferably in this embodiment, a second sealing gasket 14 is provided between the balance throttle ring 8 and the bottom of the annular groove 18. The second countersunk bolt 15 passes through the pump cover 10 and the second sealing gasket 14 to connect the balance throttle ring 8.

[0020] Preferably in this embodiment, a plurality of annular throttle grooves 20 are provided on the side of the balance throttle ring 8 close to the wear-resistant ring 6.

[0021] Preferably in this embodiment, the wear-resistant ring 6 is made of a hard material, and the balance throttle ring 8 is made of a soft material.

[0022] Working principle: Install the present invention between the impeller 11 and the pump cover 10. The impeller balance seal ring 4 is embedded in the balance seal ring groove 9 on the pump cover 10 to form a throttling structure and form a balance chamber 13. Due to the certain gap between the wear-resistant ring 6 and the balance throttle ring 8, the different hardness of the processing materials of the two, and the setting of the annular throttle grooves 20 on the ring surface of the balance throttle ring 8, the rubbing between the wear-resistant ring 6 and the balance throttle ring 8 can be minimized.

[0023] Start the centrifugal pump and rule out other axial force loading conditions on the pump. The impeller 11 is respectively subjected to the action of three forces, namely, the force pointing to the right acting on the front cover plate 2 of the impeller, and the resultant force of the rear cover plate 3 of the impeller plus the balance chamber cover plate 12 pointing to the left. Since the pressure per unit area on the front cover plate 2 and the rear cover plate 3 of the impeller is the same, but because the force-bearing area of the front cover plate 2 of the impeller is larger than that of the rear cover plate 3 of the impeller, the axial force on the impeller 11 will be unbalanced, and the impeller 11 will tend to move to the right. At this moment, there will be high-pressure liquid flowing into the balance chamber 13 from near the impeller balance throttle ring 4 and the balance seal ring groove 9, and medium-pressure liquid flowing in from the pump shaft 19 cooling system. After the inflowing liquids converge, they can only flow into the impeller balance hole 1 through the gap between the balance throttle ring 8 and the wear-resistant ring 6, and finally return to the inlet of the impeller 11. When the impeller 11 moves to the right, the pump cover 10 is fixed. As the gap between the balance throttle ring 8 and the wear-resistant ring 6 decreases, the liquid outflow decreases, the pressure in the balance chamber 13 increases, and the pressure on the impeller balance chamber cover plate 12 increases until it increases to the point where the sum of its pressure and the pressure of the rear cover plate 3 of the impeller is balanced with the pressure of the front cover plate 2 of the impeller, making the axial force on the impeller 11 reach a stable state. When the pump outlet pressure decreases, through force analysis, the impeller 11 will tend to move to the left. At this time, the gap between the balance throttle ring 8 and the wear-resistant ring 6 will gradually increase, the liquid outflow will increase, the pressure in the balance chamber 13 will gradually decrease, and the pressure on the impeller balance chamber cover plate 12 will decrease accordingly until it decreases to the point where the sum of its pressure and the pressure of the rear cover plate 3 of the impeller is balanced with the pressure of the front cover plate 2 of the impeller, making the axial force on the impeller 11 reach a stable state, and the pump shaft 19 stops axial movement.

[0024] During the operation of the centrifugal pump, when the axial force is unbalanced (pressure change occurs), the axial force balance system repeats the above actions until a stable state is reached. During the balancing process, the axial movement of the impeller 11 is less than 0.2 mm.

[0025] The above-described embodiments are only preferred solutions of the present invention, and do not impose any form of limitation on the present invention. There are other variations and modifications without exceeding the technical solutions described in the claims.

[0026] In the description of the present invention, it should be understood that the terms indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

Claims

1. An adaptive axial force balance auxiliary device for a leak-free centrifugal pump, which is arranged between the impeller and the pump cover of the leak-free centrifugal pump. Characterized in that: It includes a wear-resistant ring and a balance throttle ring. The center of the wear-resistant ring is sleeved on the pump shaft of the centrifugal pump. The wear-resistant ring is connected to the impeller through a first countersunk bolt. There is a clamping groove on the left side of the wear-resistant ring, and the bottom surface of the impeller is clamped in the clamping groove. There are diversion holes on the wear-resistant ring, and the diversion holes are communicated with the balance holes of the impeller. The balance throttle ring is located on the right side of the wear-resistant ring. The center of the balance throttle ring is sleeved on the pump shaft of the centrifugal pump. The pump cover is provided with an annular groove, and both the wear-resistant ring and the balance throttle ring are embedded in the annular groove. The balance throttle ring is fixed on the pump cover through a second countersunk bolt. The gap between the wear-resistant ring and the balance throttle ring is less than 0.05 mm.

2. The adaptive axial force balance auxiliary device for a leak-free centrifugal pump according to claim 1. Characterized in that: There are several annular throttle grooves on the side of the balance throttle ring close to the wear-resistant ring.

3. The adaptive axial force balance auxiliary device for a leak-free centrifugal pump according to claim 1. Characterized in that: There is a first sealing gasket between the wear-resistant ring and the bottom surface of the impeller, and the first sealing gasket is provided with through holes communicated with the balance holes.

4. The adaptive axial force balance auxiliary device for a leak-free centrifugal pump according to claim 1. Characterized in that: There is a second sealing gasket between the balance throttle ring and the bottom of the annular groove.

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