Double balanced hub structure low speed mining multistage centrifugal pump

Abstract

The present invention provides a low-speed multi-stage centrifugal pump for mining with a double-balancing hub structure. An inner balancing hub and an outer balancing hub are designed at the balancing hub position. A plurality of balancing cavities are designed corresponding to the inner balancing hub, the outer balancing hub and the balancing bushing. At the same time, a plurality of balancing gaps are designed corresponding to the assembly position. While balancing the axial force, the throttling loss and leakage are effectively reduced. The centrifugal pump power can be greater than 300 cubic meters per hour and the lift is higher than 1000 meters.

Description

Technical Field

[0001] The invention relates to the technical field of centrifugal pumps, and in particular to a low-speed multi-stage centrifugal pump for mining with a double-balanced hub structure. Background Art

[0002] A high-flow centrifugal pump is a centrifugal pump with a very high water output per hour or minute. When a high-flow centrifugal pump is working, due to the high water output and high head, the centrifugal pump can balance the axial force through the design of the balancing hub. The balancing hub is a cylindrical structure, installed after the last-stage impeller, and rotates with the shaft, forming a gap between the outer surface of the balancing hub and the casing. The front end of the balancing hub is connected to the last-stage impeller, and the rear end of the balancing hub is connected to the suction port. In this way, the pressure difference acting at the position of the balancing hub forms a force opposite to the hydraulic axial force to balance the axial force. Currently existing centrifugal pumps designed with a balancing hub usually only involve a single balancing hub, which has the defects of large throttling losses and large leakage. Summary of the invention

[0003] The technical problem to be solved by the present invention is: in order to overcome the shortcomings of the prior art, the present invention provides a low-speed mining multi-stage centrifugal pump with a double-balance hub structure that has multiple throttling channels designed reasonably to effectively reduce throttling losses, reduce leakage, and effectively balance axial forces.

[0004] The technical solution adopted by the present invention to solve its technical problems is: a double-balanced hub structure low-speed mining multi-stage centrifugal pump, comprising a pump body and a rotor assembly rotatably connected in the pump body, the rotor assembly comprising a rotating shaft and a plurality of impellers fixed on the rotating shaft, a guide vane is also crimped between the pump body and the top of the guide vane, the pump body is respectively provided with a water inlet section and a water outlet section, the water inlet section is located at the front end, the water outlet section is located at the rear end, the impeller at the rear end is a final-stage impeller, the guide vane at the rear end is a final-stage guide vane, an inner balancing hub is provided at the rear end of the final-stage impeller, the inner balancing hub is outer-circulated on the rotating shaft, and a pressure cover is crimped at the rear end of the inner balancing hub, an outer balancing hub is also matched and connected on the outer circumferential surface of the inner balancing hub, the front end of the outer balancing hub is opposite to the front end of the inner balancing hub, the outer circumferential surface of the outer balancing hub is crimped and fixed by the water outlet section, the axial length of the inner balancing hub is greater than the axial length of the outer balancing hub, and the rear end of the inner balancing hub corresponds to the outer balancing hub extending out The rear end face, the inner balancing hub corresponds to the outer circumferential surface of the rear end extending out of the outer balancing hub, and a balancing bushing is crimped and fixed thereon; the rear pump cavity is formed between the inner side surface of the last-stage guide vane and the rear end face of the last-stage impeller, and the connecting end face of the inner balancing hub and the outer balancing hub is hollow and has an intermediate balancing cavity, and the intermediate balancing hub and the rear pump cavity are connected by an intermediate balancing gap; the outer circumferential surface of the outer balancing hub is concave and has an outer balancing cavity at the crimping position corresponding to the water outlet section, and a connecting balancing cavity is also provided between the balancing bushing and the outer balancing hub, and the outer balancing cavity and the connecting balancing cavity are connected through a balancing hole; the rear end face of the inner balancing hub is also concave and has a rear balancing cavity, and there are gaps between the pressure cover, the inner balancing hub, the outer balancing hub and the balancing bushing, and the gap connects the rear balancing cavity, the intermediate balancing cavity and the connecting balancing cavity, and the gap is also connected to a balancing return pipe, and the other end of the balancing return pipe is connected to the water inlet section of the pump body.

[0005] In the above scheme, two inner and outer balancing hubs are cleverly designed and correspond to each connecting end face respectively. The gap between each connecting face of the balancing hub is used as a throttling channel, and three interconnected balancing chambers are designed accordingly. During operation, the pressure difference between the front and rear end faces of the inner and outer balancing hubs can be effectively balanced through the flow of the medium. The original throttling amount and leakage amount are used as the balancing medium, which effectively reduces the throttling loss and leakage amount, and facilitates to increase the flow and head of the centrifugal pump.

[0006] Furthermore, the intermediate balancing cavity is arranged at the end surface connection position of the inner balancing hub and the outer balancing hub, and the inner balancing hub and the outer balancing hub are relatively concave to form a groove at the connecting end surfaces, and the two grooves are relatively closed to form the intermediate balancing cavity. There is a gap between the connecting circumferential surfaces of the inner balancing hub and the outer balancing hub along the axial direction of the rotating shaft, and the gap is the intermediate balancing gap.

[0007] Furthermore, in order to facilitate the installation between the inner balancing hub, the rotating shaft and the last-stage impeller, the front end of the inner balancing hub is provided with a countersunk hole, and the rear end of the last-stage guide vane is correspondingly inserted in the countersunk hole and is crimped between the circumferential inner wall of the inner balancing hub corresponding to the countersunk hole and the outer circumferential surface of the rotating shaft. A top sleeve is also crimped between the groove bottom of the countersunk hole and the last-stage impeller, and the groove bottom and the top sleeve are sealed by an O-ring. There is a tight balancing gap between the outer side surface of the O-ring corresponding to the groove bottom of the contact surface between the top sleeve and the groove body and the rear pump chamber.

[0008] Furthermore, an O-ring is used to seal the outer circumferential surface of the outer balancing hub corresponding to the front end of the upper balancing chamber and the water outlet section. The outer circumferential surface of the outer balancing hub at the front end of the O-ring is connected to the rear pump chamber to form an external balancing gap. The external balancing gap is formed by the inner circumferential surface of the water outlet section, the inner circumferential surface of the last-stage guide vane and the outer circumferential surface of the outer balancing hub.

[0009] Furthermore, the balancing hole is arranged in the outer balancing hub, and correspondingly connects the balancing cavity and the outer balancing cavity.

[0010] Preferably, the balancing bushing is fixed to the gland and the water outlet section by bolts, and the outer balancing hub is also fixed to the water outlet section by bolts.

[0011] The beneficial effect of the present invention is that the double-balance hub structure low-speed mining multi-stage centrifugal pump of the present invention has a reasonable structural design, an inner balance hub and an outer balance hub are designed, and a plurality of balance cavities and balance gaps are correspondingly designed as throttling channels. While balancing the axial force, the throttling loss is effectively reduced and the leakage is reduced. The centrifugal pump power can be greater than 300 cubic meters / hour and the head is higher than 1000 meters. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0013] Figure 1 It is a structural schematic diagram of the best embodiment of the present invention.

[0014] Figure 2 yes Figure 1 A magnified schematic diagram of center A.

[0015] In the figure, 1, gland 2, inner balancing hub 3, outer balancing hub 4, balancing return pipe 5, balancing bushing 6, last-stage guide vane 7, water outlet section 8, last-stage impeller 9, rear pump chamber 10, rear balancing chamber 11, middle balancing chamber 12, connecting balancing chamber 13, balancing hole 14, outer balancing chamber 15, outer balancing gap 16, middle balancing gap 17, top tightening balancing gap 18, and top sleeve. DETAILED DESCRIPTION

[0016] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0017] like Figure 1 and Figure 2 The double-balanced hub structure low-speed mining multistage centrifugal pump shown is the best embodiment of the present invention, comprising a pump body and a rotor assembly rotatably connected in the pump body. The rotor assembly comprises a rotating shaft and a plurality of impellers fixed on the rotating shaft, and a guide vane is crimped between the pump body and the top of the guide vane. The pump body is provided with a water inlet section and a water outlet section 7, respectively, the water inlet section is located at the front end, and the water outlet section 7 is located at the rear end. The impeller at the rear end is a final-stage impeller 8, and the guide vane at the rear end is a final-stage guide vane 6.

[0018] The inner balancing hub 2 is sleeved on the rotating shaft and arranged at the rear end of the last-stage impeller 8, and a gland 1 is crimped on the rear end of the inner balancing hub 2. The outer balancing hub 3 is fitted on the outer circumference of the inner balancing hub 2. The outer circumference of the outer balancing hub 3 is crimped and fixed by the water outlet section 7 and the last-stage guide vane 6, and the front end of the outer balancing hub 3 and the front end of the inner balancing hub 2 are flush with the inner side surface of the last-stage guide vane 6. The axial length of the inner balancing hub 2 is greater than the axial length of the outer balancing hub 3, and the rear end of the inner balancing hub 2 corresponds to the rear end surface extending out of the outer balancing hub 3, and a balancing bushing 5 is crimped and fixed on the outer circumference of the inner balancing hub 2 corresponding to the rear end extending out of the outer balancing hub 3. The balancing bushing 5 is fixed to the gland 1 and the water outlet section 7 by bolts, and the outer balancing hub 3 is also fixed to the water outlet section 7 by bolts.

[0019] The rear pump cavity 9 is formed between the inner side surface of the last-stage guide vane 6 and the rear end surface of the last-stage impeller 8. The connecting end surface of the inner balancing hub 2 and the outer balancing hub 3 is hollow with an intermediate balancing cavity 11. The intermediate balancing hub and the rear pump cavity 9 are connected with an intermediate balancing gap 16. The intermediate balancing cavity 11 is arranged at the connecting position of the end surfaces of the inner balancing hub 2 and the outer balancing hub 3, and the inner balancing hub 2 and the outer balancing hub 3 are relatively concave at the connecting end surfaces to form a groove, and the two grooves are relatively closed to form the intermediate balancing cavity 11. There is a gap between the connecting circumferential surfaces of the inner balancing hub 2 and the outer balancing hub 3 along the axial direction of the rotating shaft, and the gap is the intermediate balancing gap 16.

[0020] The outer circumferential surface of the outer balancing hub 3 is concave at the crimping position corresponding to the water outlet section 7 to have an outer balancing cavity 14, and a connecting balancing cavity 12 is also provided between the balancing bushing 5 and the outer balancing hub 3. A balancing hole 13 is provided inside the outer balancing hub 3, and the balancing hole 13 communicates and connects the balancing cavity 12 and the outer balancing cavity 14. In actual processing, the shape of the outer balancing cavity 14 can be designed as an inner concave structure with an isosceles trapezoidal cross section along the axial direction, and the shorter bottom side of the isosceles trapezoid is the bottom of the inner concave structure.

[0021] The rear end surface of the inner balancing hub 2 is concave with a rear balancing cavity 10. There are gaps between the gland 1, the inner balancing hub 2, the outer balancing hub 3, and the balancing bushing 5. The gap connects the rear balancing cavity 10, the middle balancing cavity 11, and the connecting balancing cavity 12. The gap is also connected to a balancing return pipe 4. The other end of the balancing return pipe 4 is connected to the water inlet section of the pump body. The rear balancing cavity 10 is designed as a right-angled trapezoidal structure along the axial section, and the shorter bottom side of the right-angled trapezoid is the concave groove bottom position. The shorter bottom side can concentrate the pressure toward the front end to provide axial force for the balance of the balancing hub.

[0022] In actual design, in order to facilitate the installation between the inner balance hub 2 and the rotating shaft and the last-stage impeller 8, the front end of the inner balance hub 2 has a countersunk hole, and the rear end of the last-stage guide vane 6 is correspondingly inserted in the countersunk hole and is pressed between the circumferential inner wall of the corresponding countersunk hole of the inner balance hub 2 and the outer peripheral surface of the rotating shaft. A top sleeve 18 is also pressed between the groove bottom of the countersunk hole and the last-stage impeller 8. At the same time, in order to reduce the excessive flow of the medium in the high-pressure area of ​​the front end of the balance hub to the balance cavity, the groove bottom and the top sleeve 18 are sealed by an O-ring, and there is a top-tightening balance gap 17 between the outer side of the O-ring corresponding to the groove bottom of the top sleeve 18 and the rear pump cavity 9 at the contact surface of the groove body. In order to seal the gap between the outer balancing hub 3 and the front end of the outer balancing cavity 14 corresponding to the water outlet section 7, an O-ring is used to seal the outer circumferential surface of the front end of the upper balancing cavity of the outer balancing hub 3 and the water outlet section 7. The outer circumferential surface of the outer balancing hub 3 at the front end of the O-ring is connected to the rear pump cavity 9 to form an outer balancing gap 15. The outer balancing gap 15 is formed by the inner circumferential surface of the water outlet section 7, the inner circumferential surface of the last-stage guide vane 6 and the outer circumferential surface of the outer balancing hub 3.

[0023] In the above scheme, the outer balancing gap 15, the top balancing gap 17 and the middle balancing gap 16 are connected with the rear pump chamber 9, but the outer balancing gap 15 and the top balancing gap 17 are sealed with O-rings, and the high-pressure medium in the rear pump chamber 9 will not leak from these two gaps, which effectively improves the throttling effect and reduces the throttling loss. The rear pump chamber 9 is connected with the balancing return pipe 4 mainly through the middle balancing gap 16, and the middle balancing gap 16 penetrates the middle balancing chamber 11, and the middle balancing chamber 11 is connected with the rear balancing chamber 10 and the connecting balancing chamber 12 through the gap formed during the assembly process, and the connecting balancing chamber 12 is connected with the outer balancing chamber 14 through the balancing hole 13, so that the connection between the middle balancing chamber 11, the rear balancing chamber 10, the connecting balancing chamber 12 and the outer balancing chamber 14 is realized. In the balancing process, the high-pressure medium in the rear pump chamber 9 can enter the middle balancing chamber 11 through the throttling channel formed by the middle balancing gap 16, and disperse into the rear balancing chamber 10, the connecting balancing chamber 12 and the outer balancing chamber 14 under the action of each gap. Excessive medium entering the rear balancing chamber 10 is transported back to the water inlet section through the balancing return pipe 4 with pressure, providing a certain amount of pressurization for the water inlet. The medium entering the connecting balancing chamber 12, on the one hand, enters the outer balancing chamber 14 through the balancing hole 13, and on the other hand, the medium stored in the connecting balancing chamber 12 is filled in the chamber, and at the same time, a forward pressure is applied to the outer balancing hub 3, so that the outer balancing hub 3 can achieve balance. Similarly, the medium entering the rear balancing chamber 10 provides a forward pressure for the inner balancing hub 2, and at the same time, the excess part is recovered through the balancing return pipe 4 and passed into the water inlet section, providing pressurization for the water inlet section.

[0024] The double-balanced hub structure of the low-speed mining multistage centrifugal pump is designed in this way. The structure is reasonable, and the inner and outer balance hubs are cleverly designed, corresponding to each connection end face respectively, and the gaps between the connection faces of the balance hubs and multiple balance cavities are used as throttling channels. During operation, the pressure difference between the front and rear end faces of the inner and outer balance hubs can be effectively balanced through the flow of the medium, and the original throttling amount and leakage amount are used as the balancing medium. While balancing the axial force, the throttling loss and leakage amount are effectively reduced. The centrifugal pump force can be greater than 300 cubic meters / hour, and the head is higher than 1000 meters.

[0025] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A low-speed multistage centrifugal pump for mining with a double balanced hub structure, comprising a pump body and a rotor assembly rotatably connected in the pump body, the rotor assembly comprising a rotating shaft and a plurality of impellers fixed on the rotating shaft, a guide vane is crimped between the pump body and the top of the guide vane, the pump body is provided with a water inlet section and a water outlet section (7), the water inlet section is located at the front end, the water outlet section (7) is located at the rear end, the impeller at the rear end is a final stage impeller (8), and the guide vane at the rear end is a final stage guide vane (6), characterized in that: The rear end of the last-stage impeller (8) is provided with an inner balancing hub (2), the inner balancing hub (2) is outer-circumferentially mounted on the rotating shaft, and a gland (1) is crimped onto the rear end of the inner balancing hub (2); an outer balancing hub (3) is also matched and connected to the outer circumferential surface of the inner balancing hub (2); the front end of the outer balancing hub (3) is opposite to the front end of the inner balancing hub (2); the outer circumferential surface of the outer balancing hub (3) is crimped and fixed by a water outlet section (7); the axial length of the inner balancing hub (2) is greater than the axial length of the outer balancing hub (3); the rear end of the inner balancing hub (2) corresponds to the rear end surface of the outer balancing hub (3); a balancing bushing (5) is crimped and fixed onto the outer circumferential surface of the inner balancing hub (2) corresponding to the rear end surface of the outer balancing hub (3); a rear pump cavity (9) is formed between the inner side surface of the last-stage guide vane (6) and the rear end surface of the last-stage impeller (8); the inner The connecting end surfaces of the balancing hub (2) and the outer balancing hub (3) are hollow and have an intermediate balancing cavity (11), and the intermediate balancing cavity (11) and the rear pump cavity (9) are connected to each other and have an intermediate balancing gap (16); the outer circumferential surface of the outer balancing hub (3) is concave at a position corresponding to the crimping position of the water outlet section (7) and has an outer balancing cavity (14); a connecting balancing cavity (12) is further provided between the balancing bushing (5) and the outer balancing hub (3), and the outer balancing cavity (14) and the connecting balancing cavity (12) are connected to each other via a balancing hole (13); the balancing hole (13) is provided in the outer balancing hub (3) and correspondingly connects the connecting balancing cavity (12) and the outer balancing cavity (14); the three balancing cavities, namely the outer balancing cavity (14), the intermediate balancing cavity (11) and the connecting balancing cavity (12), are connected to each other; The rear end surface of the inner balancing hub (2) is also concave and has a rear balancing cavity (10). There are gaps between the gland (1), the inner balancing hub (2), the outer balancing hub (3) and the balancing bushing (5). The gaps connect the rear balancing cavity (10), the middle balancing cavity (11) and the connecting balancing cavity (12). The gaps are also externally connected to a balancing return pipe (4). The other end of the balancing return pipe (4) is connected to the water inlet section of the pump body.

2. The low-speed multistage centrifugal pump for mining with a double balanced hub structure as claimed in claim 1, characterized in that: The intermediate balancing cavity (11) is arranged at the end surface connection position of the inner balancing hub (2) and the outer balancing hub (3), and the inner balancing hub (2) and the outer balancing hub (3) are both relatively concave at the connection end surfaces to form a groove, and the two grooves are relatively closed to form the intermediate balancing cavity (11), and there is a gap between the connection circumferential surfaces of the inner balancing hub (2) and the outer balancing hub (3) along the axial direction of the rotating shaft, and the gap is the intermediate balancing gap (16).

3. The low-speed mining multistage centrifugal pump with a double balanced hub structure as claimed in claim 1, characterized in that: The front end of the inner balancing hub (2) has a countersunk hole, the rear end of the last-stage guide vane (6) is correspondingly inserted into the countersunk hole and is pressed between the circumferential inner wall of the inner balancing hub (2) corresponding to the countersunk hole and the outer circumferential surface of the rotating shaft, a top sleeve (18) is also pressed between the groove bottom of the countersunk hole and the last-stage impeller (8), the groove bottom and the top sleeve (18) are sealed by an O-ring, and a top-tightening balancing gap (17) is provided between the outer side surface of the O-ring corresponding to the groove bottom of the top sleeve (18) and the rear pump chamber (9) at the contact surface between the top sleeve (18) and the groove body.

4. The low-speed mining multistage centrifugal pump with a double balanced hub structure as claimed in claim 1, characterized in that: An O-ring is used to seal the outer circumferential surface of the outer balancing hub (3) at the front end of the upper balancing chamber and the water outlet section (7). The outer circumferential surface of the outer balancing hub (3) at the front end of the O-ring is connected to the rear pump chamber (9) to form an outer balancing gap (15). The outer balancing gap (15) is formed by the inner circumferential surface of the water outlet section (7), the inner circumferential surface of the last-stage guide vane (6) and the outer circumferential surface of the outer balancing hub (3).

5. The low-speed mining multistage centrifugal pump with a double balanced hub structure as claimed in claim 1, characterized in that: The balancing bushing (5) is fixed to the gland (1) and the water outlet section (7) by bolt locking, and the outer balancing hub (3) is also fixed to the water outlet section (7) by bolt locking.

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