CN213016922U

CN213016922U - Multistage centrifugal pump with double balance drums

Info

Publication number: CN213016922U
Application number: CN202021881501.2U
Authority: CN
Inventors: 陆显明; 廖榴; 王立
Original assignee: Hunan Lishengde Energy Saving Technology Co ltd
Current assignee: Hunan Lishengde Energy Saving Technology Co ltd
Priority date: 2020-09-02
Filing date: 2020-09-02
Publication date: 2021-04-20
Anticipated expiration: 2030-09-02

Abstract

The utility model discloses a multistage centrifugal pump with double balance drum, its characterized in that: the balance drum comprises a balance drum seat, a left balance drum, a right balance drum and a balance pipe, wherein the suction section is provided with a low-pressure cavity, the outlet section is provided with a high-pressure cavity, the right side of the outlet section is provided with a balance cavity, and the right side of the left balance drum and the left side of the right balance drum enclose a buffer cavity; the balance drum seat is embedded in the right inner hole of the outlet section; the balance drum seat is provided with two sections of step inner holes, the left balance drum is arranged in the left end inner hole of the balance drum seat, and the right balance drum is arranged in the right end inner hole of the balance drum seat. The utility model adopts the structure of the double balance drums, which plays the dual roles of balancing the axial force and the guide bearing, increases the flow resistance, reduces the volume loss and the disc friction loss, and improves the efficiency of the pump; meanwhile, the guide bearing function of the left balance drum increases the rigidity of the pump, reduces the bearing load and prolongs the service life of the bearing.

Description

Multistage centrifugal pump with double balance drums

Technical Field

The utility model relates to a water pump field especially relates to a multistage centrifugal pump with double balance drum.

Background

The multistage pump is a centrifugal pump which is particularly widely applied, the multistage pump generates a large axial force due to the working principle of the multistage pump, the axial force needs to be balanced, otherwise, a bearing is damaged, and at present, a balancing drum is mostly used for balancing the axial force. The balance axial force of the balance drum in the prior art adopts a single balance drum to balance the axial force, the flow resistance of the single balance drum is smaller, so the differential pressure at two ends of the balance drum is smaller, the diameter of the balance drum has to be increased in order to generate the same balance force, the friction loss of a disc is increased, meanwhile, the gap between the balance drum and a balance seat is increased, the volume loss is increased, and finally, the efficiency of a pump is reduced; on the other hand, the multi-stage pump has larger shaft length and larger deflection, which easily causes bearing damage and eccentric wear of the balance drum, and meanwhile, when the multi-stage pump works in an abrasive medium, the abrasion problem of the balance drum also seriously affects the service life of the balance drum.

Therefore, the balancing of the axial forces of the balancing drums of the prior art has numerous drawbacks: the efficiency of the pump is reduced and the life of the balance drum and bearings is shorter.

Disclosure of Invention

In order to solve the problem, the utility model provides a multistage centrifugal pump with two balance drums has balanced the axial force betterly, has improved the efficiency and the bearing life-span of pump, can effectively solve the problem that exists among the background art.

The utility model adopts the technical proposal that:

a multistage centrifugal pump with double balance drums comprises a suction section, an impeller, a guide vane, a middle section, a shaft, an outlet section, a balance drum seat, a left balance drum, a right balance drum and a balance pipe, wherein the suction section is provided with a low-pressure cavity, the outlet section is provided with a high-pressure cavity, the right side of the outlet section is provided with a balance cavity, and the right side of the left balance drum and the left side of the right balance drum enclose a buffer cavity; the balance drum seat is embedded in the right inner hole of the outlet section; the balance drum seat is provided with two sections of step inner holes, and the diameter of the inner hole at the left end is smaller than that of the inner hole at the right end; the suction section, the guide vanes, the middle sections and the outlet section are sequentially connected from left to right; the impellers, the left balance drum and the right balance drum are sequentially sleeved on the shaft from left to right; the left balance drum is arranged in an inner hole at the left end of the balance drum seat, and the right balance drum is arranged in an inner hole at the right end of the balance drum seat; the left balance drum and the right balance drum are connected with the shaft through keys.

As a further improvement, the left balance drum and the balance drum seat form a first-level balance drum, and the right balance drum and the balance drum seat form a second-level balance drum.

As a further improvement, the hole spraying carbide of balanced drum seat, the material of the balanced drum in a left side is graphite impregnated epoxy, the material of the balanced drum in the right side is silicon nitride.

As a further improvement of the utility model, the roughness values of the excircle of the left balance drum, the excircle of the right balance drum and the inner hole of the balance drum seat are not more than Ra0.1; the clearance between the excircle of the left balance drum and the inner hole at the left end of the balance drum seat is 0.05-0.1 mm, and the left balance drum and the balance drum seat play a role of a guide bearing; the gap between the outer circle of the right balance drum and the inner hole at the right end of the balance drum seat is 0.15-0.2 mm; the excircle of left side balance drum is equipped with 6 width and is 5mm degree of depth for the straight flute of 0.3 mm.

As a further improvement of the utility model, the outlet section and the lower part of the balance drum seat are provided with vertical sand discharge holes which communicate the buffer cavity with the outside; the sand discharge hole is provided with a plug screw for plugging.

As a further improvement of the present invention, the low pressure chamber is communicated with the balance chamber through a balance pipe.

Compared with the prior art, the beneficial effects of the utility model are that:

1. the efficiency of multistage pump has been improved: the friction loss and the volume loss of the disc are reduced, and the efficiency of the pump is improved.

2. The life-span of balancing drum and bearing has been improved: on the one hand, the rigidity of the shaft is increased, and on the other hand, the wear resistance of the balance drum and the effect of balancing the axial force are improved, so that the service life of the balance drum and the service life of the bearing are prolonged.

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the description, do not constitute a limitation of the invention, in which:

fig. 1 is a schematic structural diagram of the present invention.

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

In the figure: 1. the device comprises a suction section, 2, an impeller, 3, guide vanes, 4, a middle section, 5, an outlet section, 6, a balance drum seat, 7, a left balance drum, 8, a right balance drum, 9, a key, 10, a screw plug, 11, a balance pipe, 12 shafts, 100, a low-pressure cavity, 101, a high-pressure cavity, 102, a balance cavity, 103, a buffer cavity, 104 and a sand discharge hole.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "left", "right", "inside", "outside", "both ends", "one end", "the other end", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "disposed," "connected," and the like are to be construed broadly, and for example, "connected" may be a fixed connection, a detachable connection, or an integral connection; either mechanically or electrically. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

As shown in fig. 1-2, the utility model provides a multistage centrifugal pump with two balanced drums, including inhaling section, impeller, stator, middle section, axle, export section, balanced drum seat, left balanced drum, right balanced drum and balanced pipe, inhale the section and set up the low pressure chamber, the export section sets up the high pressure chamber, and the export section right side sets up balanced chamber, and the right side of left side balanced drum encloses into the cushion chamber with the left side of right balanced drum, and the low pressure chamber communicates through balanced pipe with balanced chamber, and the pressure in balanced chamber just so nearly equals the pressure in low pressure chamber. The balance drum seat is embedded in the right inner hole of the outlet section. The balance drum seat is provided with two sections of step inner holes, and the diameter of the inner hole at the left end is smaller than that of the inner hole at the right end. The suction section, the guide vanes, the middle sections and the outlet section are sequentially connected from left to right. The plurality of impellers, the left balance drum and the right balance drum are sequentially sleeved on the shaft from left to right. The left balance drum is arranged in the inner hole at the left end of the balance drum seat, and the right balance drum is arranged in the inner hole at the right end of the balance drum seat. The left balance drum and the right balance drum are connected with the shaft through keys. When the multistage pump works, because the pressure at the suction side of each stage of impeller is lower than the pressure at the other side, the impeller can be subjected to a water thrust opposite to the liquid suction direction, and the resultant force of the water thrust applied to all the impellers is the axial force of the multistage pump.

The utility model discloses a balanced axial force of two-stage balance drum, left balance drum and balanced drum seat constitute the balanced drum of first order, and the balanced drum of right side and balanced drum seat constitute the balanced drum of second order. The left side of the left balance drum is a high-pressure cavity and is acted by high pressure, the right side of the right balance drum is a balance cavity and is acted by low pressure, so that a pressure difference is applied to the left side and the right side of the two-stage balance drum, the acting force direction of the pressure difference is opposite to the axial force, the balance force of the axial force is formed, and if the balance drum is properly designed, the balance force is equal to the axial force, and finally the balance of the axial force is realized. Because the two-stage balance drum is adopted, when a medium passes through the radial gaps between the left balance drum and the balance seat, the medium enters the balance cavity from the high-pressure cavity, the flow resistance is larger than that in the prior art, so that the pressure difference is larger, the medium flow passing through the gaps is smaller, the volume loss is reduced, and the volume efficiency is improved; meanwhile, as the flow resistance and the pressure difference are increased, the diameter of the balance drum which is smaller than that of the prior art can be used for generating the same balance force, according to hydraulics, the friction loss of the rotor disc is in direct proportion to the quintic power of the disc diameter, and the disc friction loss of the two-stage balance drum is lower than that of the prior art, so that the hydraulic efficiency is improved. Therefore, the utility model discloses a multistage centrifugal pump with two balance drums has higher complete machine efficiency than prior art's multistage centrifugal pump.

The left balance drum is used for balancing the axial force and the guide bearing, and the right balance drum is used for balancing the axial force. The inner hole of the balance drum seat is sprayed with hard alloy, the left balance drum is made of graphite impregnated epoxy resin, the right balance drum is made of silicon nitride, and the configuration of the materials ensures that the left balance drum has self-lubricating property as a friction pair and also ensures the wear resistance of the right balance drum.

The roughness value of the excircle of left balance drum, the excircle of right balance drum and the hole of balanced drum seat all is not greater than Ra0.1, the clearance between the excircle of left balance drum and the left end hole of balanced drum seat is 0.05 ~ 0.1mm, because left balance drum plays the effect of guide bearing with balanced drum seat, the precision of guide bearing has been guaranteed to small running clearance, because the supporting role of guide bearing, the rigidity of axle has been improved, the radial load of both ends bearing has been reduced, thereby the bearing life-span has been improved. The clearance between the excircle of right side balance drum and the right-hand member hole of balance drum seat is 0.15 ~ 0.2mm, and this clearance has both guaranteed right side balance drum and balance drum seat contactless when the operation, has guaranteed certain flow resistance again, reaches the purpose of pressure release, makes to have the balance drum both sides to have certain pressure differential.

The excircle of the left balance drum is provided with 6 straight grooves with the width of 5mm and the depth of 0.3mm, which is used for preventing abrasive particles in a medium from damaging the surface of a friction pair, so that the particles can be accumulated in the grooves and washed away by the medium, and finally impurities such as the particles and the like can be accumulated in a buffer cavity. The lower parts of the outlet section and the balance drum seat are provided with vertical sand discharge holes which communicate the buffer cavity with the outside. The sand discharge hole is provided with a plug screw for plugging, and the plug screw can be opened when necessary to discharge impurities such as particles in the buffer cavity from the sand discharge hole.

In summary, the utility model adopts the structure of the double balance drums, which plays the dual role of balancing the axial force and the guide bearing, increases the flow resistance, reduces the volume loss and the disc friction loss, and improves the efficiency of the pump; meanwhile, the guide bearing function of the left balance drum increases the rigidity of the pump, reduces the bearing load and prolongs the service life of the bearing.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.

Claims

1. The utility model provides a multistage centrifugal pump with two balance drums, includes suction section, impeller, stator, middle section, axle and export section, its characterized in that: the balance type vacuum pump further comprises a balance drum seat, a left balance drum, a right balance drum and a balance pipe, wherein the suction section is provided with a low-pressure cavity, the outlet section is provided with a high-pressure cavity, the right side of the outlet section is provided with a balance cavity, and the right side of the left balance drum and the left side of the right balance drum enclose a buffer cavity; the balance drum seat is embedded in the right inner hole of the outlet section; the balance drum seat is provided with two sections of step inner holes, and the diameter of the inner hole at the left end is smaller than that of the inner hole at the right end; the suction section, the guide vanes, the middle sections and the outlet section are sequentially connected from left to right; the impellers, the left balance drum and the right balance drum are sequentially sleeved on the shaft from left to right; the left balance drum is arranged in an inner hole at the left end of the balance drum seat, and the right balance drum is arranged in an inner hole at the right end of the balance drum seat; the left balance drum and the right balance drum are connected with the shaft through keys.

2. The multistage centrifugal pump with dual balancing drums of claim 1, wherein: the left balance drum and the balance drum seat form a first-stage balance drum, and the right balance drum and the balance drum seat form a second-stage balance drum.

3. The multistage centrifugal pump with double balancing drums according to claim 1 or 2, characterized in that: the inner hole of the balance drum seat is sprayed with hard alloy, the left balance drum is made of graphite impregnated epoxy resin, and the right balance drum is made of silicon nitride.

4. The multistage centrifugal pump with dual balancing drums of claim 1, wherein: the roughness values of the outer circle of the left balance drum, the outer circle of the right balance drum and the inner hole of the balance drum seat are not more than Ra0.1; the clearance between the excircle of the left balance drum and the inner hole at the left end of the balance drum seat is 0.05-0.1 mm, and the left balance drum and the balance drum seat play a role of a guide bearing; the gap between the outer circle of the right balance drum and the inner hole at the right end of the balance drum seat is 0.15-0.2 mm; the excircle of left side balance drum is equipped with 6 width and is 5mm degree of depth for the straight flute of 0.3 mm.

5. The multistage centrifugal pump with dual balancing drums of claim 1, wherein: the lower parts of the outlet section and the balance drum seat are provided with vertical sand discharge holes which communicate the buffer cavity with the outside; the sand discharge hole is provided with a plug screw for plugging.

6. The multistage centrifugal pump with dual balancing drums of claim 1, wherein: the low pressure cavity is communicated with the balance cavity through a balance pipe.