CN211397914U

CN211397914U - Two-end supporting type single-sealing multistage centrifugal pump

Info

Publication number: CN211397914U
Application number: CN201922269779.8U
Authority: CN
Inventors: 于晓滨
Original assignee: Shenyang Huada Fluid Technology Co ltd
Current assignee: Shenyang Huada Fluid Technology Co ltd
Priority date: 2019-12-17
Filing date: 2019-12-17
Publication date: 2020-09-01
Anticipated expiration: 2029-12-17

Abstract

The utility model belongs to the field of centrifugal pumps, and provides a two-end supporting type single-sealing multistage centrifugal pump, which comprises a pump body, wherein a multistage impeller is arranged in the pump body; one end of the pump body is a suction end, and the other end of the pump body is a discharge end; the centrifugal pump also comprises a pump shaft which sequentially penetrates through the ejection end, the multi-stage impeller and the suction end, a driving end shaft extension is arranged at the suction end on one side close to the pump shaft, and the driving end shaft extension is connected with a driving device; the suction end is internally provided with a built-in sliding bearing, and the discharge end is provided with an external sliding bearing; the built-in sliding bearing comprises a bearing sleeve and a bearing bush which are arranged in sequence from inside to outside, and the bearing sleeve is in running fit with the bearing bush; the bearing bush is fixed on the pump shaft through a first anti-rotation pin, the bearing bush is fixed in the suction end through a second anti-rotation pin, and a diversion trench is further axially arranged on the bearing bush.

Description

Two-end supporting type single-sealing multistage centrifugal pump

Technical Field

The utility model belongs to the centrifugal pump field provides a both ends support formula single seal multistage centrifugal pump very much.

Background

The centrifugal pump is a rotating machine, and a corresponding sealing device is needed between a rotating part and a static part in order to prevent leakage of a conveying medium, and various structural forms such as a packing seal, a hydraulic seal, a mechanical seal and the like are commonly used and are selected and applied according to the use condition. With the advancement of the state of technology, mechanical seals have gained the most widespread use in centrifugal pumps, and are the most important form of seal. The multistage centrifugal pump structure is both ends support formula, has decided structurally that respectively need a set of mechanical seal at the suction end and spit out the end, and under the operating mode that carries flammable and explosive, poisonous and harmful etc. and have dangerous medium, each end is sealed still to adopt serial-type second grade mechanical seal, and it is actually 4 sets of seals work simultaneously and protect the medium outwards not to leak. The mechanical seal is a precise mechanical part rotating at high speed, the form and position tolerance and the smoothness of the surfaces of the seal movable ring and the seal static ring are required to be very high in precision, the service life of the mechanical seal is often closely related to a plurality of objective factors such as seal quality, use conditions, medium conditions, operation specifications and the like, once the stable operation conditions are damaged, the seal is easily damaged, so that the centrifugal pump is forced to stop, once the medium in the pump leaks, various accidents can be caused, even major accidents can be caused, and the life and the production safety are seriously threatened. The failure of the mechanical seal accounts for more than 65% of the failure of the centrifugal pump by data statistics, and the safe production is threatened.

The multistage centrifugal pump is an important structural form of the centrifugal pump, and conforms to the international standard API610 centrifugal pump for petroleum, heavy chemistry and natural gas industry, and the structural code is BB 4. Referring to fig. 1, the pump head is increased step by the series operation of a plurality of impellers, and finally the outlet can reach a very high pressure. The total lift of the pump is the product of the single-stage impeller lift and the impeller stage number, and different lift requirements can be realized by different impeller stage numbers. The multistage centrifugal pump has wide application in various industrial departments of national economy such as thermal power generation, petrochemical industry, seawater desalination, oil field water injection, chlor-alkali soda, coal chemical industry and the like.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a both ends support formula single seal multistage centrifugal pump, through the project organization of an innovation, realize brand-new both ends support formula multistage centrifugal pump design method, make the new product only be equipped with one set of mechanical seal of spit-out end, and only one set of external bearing part, the other end adopts the lubricated non-maintaining slide bearing of built-in medium, furthest has reduced the sealed fault point of multistage pump, the reliability of multistage centrifugal pump operation has been improved, reduce the maintenance work load, guarantee safety in production.

The utility model provides a two-end supporting type single-sealing multistage centrifugal pump, which comprises a pump body, wherein a multistage impeller is arranged in the pump body; one end of the pump body is a suction end, and the other end of the pump body is a discharge end; the centrifugal pump also comprises a pump shaft which sequentially penetrates through the ejection end, the multi-stage impeller and the suction end, a driving end shaft extension is arranged at the suction end on one side close to the pump shaft, and the driving end shaft extension is connected with a driving device;

the suction end is internally provided with a built-in sliding bearing, and the discharge end is provided with an external sliding bearing;

the built-in sliding bearing comprises a bearing sleeve and a bearing bush which are arranged in sequence from inside to outside, and the bearing sleeve is in running fit with the bearing bush; the bearing bush is fixed on the pump shaft through a first anti-rotation pin, the bearing bush is fixed in the suction end through a second anti-rotation pin, and a diversion trench is further axially arranged on the bearing bush.

Specifically, the guide groove has the effects that liquid in the guide groove generates lifting supporting force ' Roman ' force ' when the silicon carbide bearing rotates, and a liquid film layer is generated between the bearing sleeve and the bearing bush, so that the bearing sleeve and the bearing bush are not in contact in a working state, a layer of liquid film is arranged in the middle for lubrication, no abrasion is realized, and the built-in sliding bearing can achieve a long service life.

Furthermore, an overflowing hole is formed in one side, far away from the pump shaft, of the inner portion of the suction end, and the overflowing hole is used for exchanging media inside the built-in sliding bearing with media outside the built-in sliding bearing in real time. The combined action of the overflowing hole and the diversion trench enables media inside and outside the bearing to be exchanged in real time, friction heating of the built-in sliding bearing can be effectively taken away, and the liquid film of the built-in sliding bearing is guaranteed to be intact and not vaporized.

Furthermore, one side, far away from the pump shaft, of the built-in sliding bearing is also provided with a shaft check ring, and the shaft check ring is used for axially positioning the bearing sleeve.

Furthermore, one side of the built-in sliding bearing, which is close to the pump shaft, is also provided with a hole check ring, and the hole check ring is used for axially fixing the bearing bush.

Further, the bearing sleeve is rotatably fitted with the bearing bush in a size of H7/e 8.

Further, the bearing sleeve is made of pressureless sintered silicon carbide materials; the bearing bush is made of pressureless sintered silicon carbide materials. The Mohs hardness of the silicon carbide is 9.2, the silicon carbide is second to diamond in nature and is an ultra-strong wear-resistant material, and the ultra-strong hardness of the silicon carbide enables the silicon carbide to be used well even if a medium contains trace particles and cannot be worn; the compressive strength of the pump can reach 800MPa, is far greater than that of metal, and can bear the weight of a heavy-load multistage pump rotor; the silicon carbide is stable in chemical property, does not react with any substance, is suitable for various media, and is the most ideal medium lubrication sliding bearing material.

The utility model discloses a mechanical seal of cancellation multistage pump suction end reduces sealed quantity half for pump mechanical seal's fault rate reduces 50% at least, and the reliability improves by a wide margin, especially when carrying inflammable and explosive, poisonous and harmful, the medium operating mode that does not allow the leakage, has important meaning.

The external thin oil lubrication rolling bearing part at the suction end of the pump is cancelled and changed into the built-in sliding bearing, so that the suction end bearing part completely avoids the interference of the external environment, is lubricated by a medium, realizes the maintenance-free performance of the end bearing, and improves the operation reliability of the multi-stage pump to a certain extent.

Except that the suction section and the pump shaft need to be redesigned and manufactured, other parts can be used in common and exchanged with the original multi-stage pump, and the universal and series design is facilitated.

When the multi-stage pump is used for conveying flammable, explosive, toxic and harmful media without leakage, a series-connection type double-end-face seal and a corresponding sealing system are needed to be adopted to prevent the media from leaking outwards and realize the function of automatic alarm once the media leak, but the sealing and sealing system is very expensive and sometimes even exceeds the price of the multi-stage pump, and the multi-stage pump is poor in economical efficiency. Because the utility model relates to a reduce half mechanical seal, also reduce half sealed rinse-system's configuration simultaneously, will reduce the supporting cost of pump by a wide margin, obtain the price advantage in market competition. The user use unit can greatly reduce one-time purchasing cost, meanwhile, the stock of spare parts can be correspondingly reduced, and the economic benefit is obvious.

Drawings

Fig. 1 is a sectional view of a conventional multistage centrifugal pump.

Fig. 2 is a sectional view of the present invention.

Fig. 3 is an enlarged cross-sectional view of the suction end of the present invention.

Fig. 4 is a sectional view of the present invention.

Reference numerals:

the pump comprises a pump body 1, a multistage impeller 2, a suction end 3, a built-in sliding bearing 30, a bearing sleeve 31, a bearing bush 32, a first anti-rotation pin 33, a second anti-rotation pin 34, an overflowing hole 35, a retainer ring for 36 shafts, a retainer ring for 37 holes, a discharge end 4, an external sliding bearing 40, a pump shaft 5 and a drive end 51.

Detailed Description

Example 1

The embodiment provides a two-end supporting type single-sealing multistage centrifugal pump, which comprises a pump body 1, wherein a multistage impeller 2 is arranged in the pump body 1; one end of the pump body 1 is a suction end 3, and the other end of the pump body 1 is a discharge end 4; the centrifugal pump also comprises a pump shaft 5 which sequentially penetrates through the ejection end 4, the multistage impeller 2 and the suction end 3, a driving end shaft extension 51 is arranged at the suction end 3 at one side, close to the pump shaft 5, of the pump shaft, and the driving end shaft extension 51 is connected with a driving device;

the suction end 3 is provided with a built-in sliding bearing 30, and the discharge end 4 is provided with an external sliding bearing 40;

the built-in sliding bearing 30 comprises a bearing sleeve 31 and a bearing bush 32 which are arranged in sequence from inside to outside, and the bearing sleeve 31 is in running fit with the bearing bush 32; the bearing housing 31 is fixed on the pump shaft 5 by a first anti-rotation pin 33, the bearing bush 32 is fixed inside the suction end 3 by a second anti-rotation pin 34, and the bearing bush 32 is further provided with a diversion trench in the axial direction.

Specifically, the guide grooves have the function that when the silicon carbide bearing rotates, liquid in the guide grooves generates lifting supporting force ' Roman ' force ', and a liquid film layer is generated between the bearing sleeve 31 and the bearing bush 32, so that the bearing sleeve 31 and the bearing bush 32 are not in contact in a working state, a layer of liquid film is arranged in the middle for lubrication, no abrasion is realized, and the built-in sliding bearing 30 can achieve a long service life.

Furthermore, an overflow opening 34 is provided in the intake end 3 on the side remote from the pump shaft 5, and the overflow opening 35 is used for the real-time exchange of the media inside and outside the built-in sliding bearing 30. The combined action of the overflowing hole 35 and the guide groove enables the media inside and outside the bearing to be exchanged in real time, and can effectively take away the friction heating of the built-in sliding bearing 30, and the liquid film of the built-in sliding bearing 30 is ensured to be intact and not vaporized.

Furthermore, a shaft collar 36 is arranged on the side of the built-in sliding bearing 30 remote from the pump shaft 5, and the shaft collar 36 is used for axial positioning of the bearing sleeve 31.

Furthermore, a hole retaining ring 37 is arranged on the side of the built-in sliding bearing 30 close to the pump shaft 5, and the hole retaining ring 37 is used for axially fixing the bearing bush 32.

Further, the bearing sleeve 31 is rotatably fitted to the bearing bush 32 in a size of H7/e 8.

Further, the bearing sleeve 31 is made of pressureless sintered silicon carbide material; the bearing bush 32 is made of pressureless sintered silicon carbide material. The Mohs hardness of the silicon carbide is 9.2, the silicon carbide is second to diamond in nature and is an ultra-strong wear-resistant material, and the ultra-strong hardness of the silicon carbide enables the silicon carbide to be used well even if a medium contains trace particles and cannot be worn; the compressive strength of the pump can reach 800MPa, is far greater than that of metal, and can bear the weight of a heavy-load multistage pump rotor; the silicon carbide is stable in chemical property, does not react with any substance, is suitable for various media, and is the most ideal medium lubrication sliding bearing material.

In the embodiment, the bearing part at the suction end of the multistage centrifugal pump is changed into the built-in sliding bearing 30 from an external thin oil lubrication rolling bearing, the lubrication of the built-in sliding bearing 30 is lubricated by the medium, and the built-in sliding bearing 30 at the suction end is completely contained in the medium, so that the mechanical seal at the suction end is completely not needed, the seal at the suction end 3 is cancelled, and the suction end 3 is completely sealed and has no leakage.

Example 2

The difference with embodiment 1 lies in that the direction of the suction end 3 is changed, referring to fig. 4, by changing the design direction of the suction port flange of the suction end 3, the radial suction arrangement of the pump can be realized, and the suction device has wider application and is suitable for various spatial pipeline layouts of users.

The utility model is not the best known technology.

The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose of the embodiments is to enable people skilled in the art to understand the contents of the present invention and to implement the present invention, which cannot limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered by the protection scope of the present invention.

Claims

1. The utility model provides a two ends support formula single seal multistage centrifugal pump, includes the pump body (1), its characterized in that: a multi-stage impeller (2) is arranged in the pump body (1); one end of the pump body (1) is a suction end (3), and the other end of the pump body (1) is a discharge end (4); the centrifugal pump also comprises a pump shaft (5) which sequentially penetrates through the ejection end (4), the multistage impeller (2) and the suction end (3), a driving end shaft extension (51) is arranged at the suction end (3) on one side, close to the pump shaft (5), and the driving end shaft extension (51) is connected with a driving device;

the suction end (3) is internally provided with a built-in sliding bearing (30), and the discharge end (4) is provided with an external sliding bearing (40);

the built-in sliding bearing (30) comprises a bearing sleeve (31) and a bearing bush (32) which are arranged from inside to outside in sequence, and the bearing sleeve (31) is in running fit with the bearing bush (32); the bearing sleeve (31) is fixed on the pump shaft (5) through a first anti-rotation pin (33), the bearing bush (32) is fixed in the suction end (3) through a second anti-rotation pin (34), and a guide groove is further formed in the bearing bush (32) in the axial direction.

2. The two-end supported single seal multistage centrifugal pump according to claim 1, characterized in that: and an overflowing hole (35) is arranged on one side of the suction end (3) which is far away from the pump shaft (5), and the overflowing hole (35) is used for real-time exchange of media inside and outside the built-in sliding bearing (30).

3. The two-end supported single seal multistage centrifugal pump according to claim 1, characterized in that: and a shaft retainer ring (36) is further arranged on one side, away from the pump shaft (5), of the built-in sliding bearing (30), and the shaft retainer ring (36) is used for axially positioning the bearing sleeve (31).

4. The two-end supported single seal multistage centrifugal pump according to claim 1, characterized in that: one side of the built-in sliding bearing (30) close to the pump shaft (5) is also provided with a hole retainer ring (37), and the hole retainer ring (37) is used for axially fixing the bearing bush (32).

5. The two-end supported single seal multistage centrifugal pump according to claim 1, characterized in that: the size of the rotary fit between the bearing sleeve (31) and the bearing bush (32) is H7/e 8.

6. The two-end supported single seal multistage centrifugal pump according to claim 1, characterized in that: the bearing sleeve (31) is made of pressureless sintered silicon carbide material; the bearing bush (32) is made of pressureless sintered silicon carbide material.