CN111878411A - Multistage pump axial force bearing structure - Google Patents

Abstract

The invention discloses an axial force bearing structure of a multi-stage pump, comprising: a pump shaft and a multi-stage impeller assembly, the pump shaft is arranged on a bearing seat, the multi-stage impeller assembly is sleeved on the pump shaft, and the impeller assemblies of each stage are provided The impeller and guide vane are floating on the pump shaft; the lower end of the first-stage impeller in the multi-stage impeller assembly is provided with a lower circlip for limiting; the last-stage guide vane in the multi-stage impeller assembly is floating and sleeved on the pump shaft The upper end of the shaft and the upper end of the final stage guide vane are provided with an upper circlip and an adjusting shaft sleeve for limiting. In the present invention, the impeller assembly includes an impeller and a guide vane, and the guide vane is floatingly arranged on the pump shaft, so that the axial force generated by the impeller is borne by the guide vane floating, and the axial force is prevented from being loaded on the motor shaft; the first stage impeller and the last stage guide vane The blades are respectively limited by the upper circlip, the lower circlip and the adjusting sleeve, and the axial force of the first-stage impeller is transmitted to the last-stage guide vane through the pump shaft, and is carried by the last-stage guide vane to achieve the balance of the axial force and satisfy the Different structures of centrifugal pumps need to be used.

Description

Axial force bearing structure of a multistage pump

technical field

The invention relates to the technical field of multistage pumps, in particular to an axial force bearing structure of a multistage pump.

Background technique

The multi-stage centrifugal pump is a collection of two or more centrifugal pumps with the same function. The fluid channel structure shows that the medium pressure relief port of the first stage is connected to the medium inlet of the second pole, and the medium discharge port of the second stage is connected. The pressure port is communicated with the inlet of the third stage to form a multi-stage centrifugal pump in series. Multistage centrifugal pumps can meet different requirements by changing the number of pump stages (number of impellers), so they have a wide range of applications. However, with the increase of the number of stages, the problem of large axial force of the multistage centrifugal pump increases. The methods of balancing the axial force include the use of thrust bearing balance, the use of back vane balance, the use of double suction impeller balance method, the use of symmetrical distribution of impellers, the use of balance drum balance, etc. Among them, the use of thrust bearing balance is the most effective, but the The axial force is large, and the use of thrust bearings to balance the axial force will make the structure of the pump very complicated.

To this end, Chinese utility model patent CN205895628U provides a high-lift multi-stage deep well submersible pump, including a pump body, a motor and a barrel, an oil cup is arranged at the bottom of the barrel, the oil cup is fixed by a circlip, and the motor is arranged on the top of the barrel. , The pump body is arranged on the motor, the pump body includes a pump head, an upper end, a connecting part and a lower end, the pump body is provided with a transmission shaft passing through the upper end, the connecting part and the lower end, and the upper and lower ends are respectively provided with several groups The number of impeller assemblies at the upper end is greater than the number of impeller assemblies at the lower end, and a bracket is arranged in the connecting part. The high-lift multi-stage deep well submersible pump makes the motor energized through the control box and the motor shaft rotates, and the motor shaft is driven by the coupling The rotation of the drive shaft causes the impeller to rotate, and the liquid flows upward with the impeller step by step. At this time, the impeller will push and pull downward. The thrust generated by the impeller at the upper end is offset by the bracket in the connecting part, and the thrust generated by the impeller at the lower end will be offset. By offsetting the bearing seat and setting up multiple groups of impeller components in sections, the stable operation of the deep well submersible pump is realized.

However, the above-mentioned high-lift multi-stage deep well submersible pump has the following disadvantages:

(1) The pump body is set above the motor, and the motor shaft is connected to the pump shaft through a coupling. During the actual operation, the motor shaft carries part of the axial force on the pump shaft. This bearing structure is only suitable for the pump body set in The vertical multi-stage submersible pump above the motor cannot be applied to the inverted submersible pump or horizontal centrifugal pump with the motor set above the pump body;

(2) The impeller assemblies are respectively arranged in the upper end and the lower end, and the number of impeller assemblies at the upper end is greater than the number of impeller assemblies at the lower end. There are certain requirements for the number and distribution of impeller assemblies, which cannot be applied to different numbers. the impeller assembly.

In view of this, it is urgent to improve the axial force bearing structure of the existing multi-stage pump, so as to be suitable for the inverted submersible pump or the horizontal centrifugal pump to meet the needs of different impeller assemblies.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is that the existing multistage pump axial force bearing structure cannot be applied to the inverted or horizontal pump structure.

In order to solve the above-mentioned technical problems, the technical scheme adopted in the present invention is as follows:

An axial force bearing structure of a multistage pump, comprising:

The pump shaft is arranged on the bearing seat, and its upper end is used to connect with the motor shaft through the coupling;

A multi-stage impeller assembly is sleeved on the pump shaft, the impeller assemblies at each stage include an impeller and a guide vane, and the guide vane is floatingly arranged on the pump shaft;

The first-stage impeller in the multi-stage impeller assembly is sleeved on the lower end of the pump shaft, and the lower end of the first-stage impeller is provided with a lower circlip for limiting;

The last-stage guide vanes in the multi-stage impeller assembly are floatingly arranged on the upper end of the pump shaft, and the upper end of the last-stage guide vanes are provided with a circlip and an adjusting shaft sleeve for limiting.

In this solution, the pump shaft is a prism shaft.

In this solution, the upper end and the lower end of the pump shaft are provided with circlip grooves, and the upper circlip and the lower circlip are arranged in the circlip grooves.

In this solution, the adjusting shaft sleeve includes:

The lower shaft sleeve is arranged opposite to the upper end of the last-stage guide vane, and there is a floating space with the outer side of the pump shaft;

The upper shaft sleeve is arranged on the upper end of the lower shaft sleeve and is matched with the outer side surface of the pump shaft.

In this solution, the pump shaft is arranged on the bearing seat through a shaft sleeve assembly, and the shaft sleeve assembly includes:

Two inner shaft sleeves are sleeved on the upper and lower ends of the pump shaft, and are respectively arranged between the lower circlip and the first-stage impeller, and between the upper circlip and the coupling. The inner shaft sleeve is adapted to the outer side of the pump shaft;

Two outer shaft sleeves are respectively sleeved on the two inner shaft sleeves, and are matched with the bearing seat and the inner shaft sleeve at the same time.

In this solution, the inner bushing is an insert made of wear-resistant cemented carbide.

In this solution, the impeller assembly further includes:

The impeller housing includes an impeller upper cover and an impeller seat. The impeller seat is provided with a guide vane installation position, the lower end of the guide vane is inserted into the guide vane installation position, and the impeller is arranged between the guide vane and the guide vane. between the impeller seats.

In this solution, the impeller is a closed impeller, comprising a wheel hub, a wheel disc and a wheel cover arranged on the wheel hub, and blades are arranged between the wheel disc and the wheel cover; the wheel and the wheel cover are provided with blades; The outer side of the pump shaft is adapted.

In this solution, the top surface of the coupling is provided with a spline groove for connecting with the motor shaft; the bottom end of the coupling is provided with a prism groove for connecting with the pump shaft.

In this solution, the adjusting bushing and the impeller assemblies of all stages are connected in series on the pump shaft, and there is an axial serial movement distance between the adjusting bushing and the impeller assemblies of all stages, and the serial movement The spacing is 0.5-2mm.

Compared with the prior art, the multi-stage pump axial force bearing structure provided by the present invention includes a pump shaft and a multi-stage impeller assembly sleeved on the pump shaft. Each stage of the impeller assembly is provided with an impeller and a guide vane, and the guide vane floats. It is set on the pump shaft, so that the axial force generated by the impeller components at all levels is transmitted to the guide vanes, and the guide vanes are floating and carried to avoid the axial force being loaded onto the motor shaft through the pump shaft; the first-stage impeller is limited by the lower circlip , the last-stage guide vane is limited by the upper circlip, so that the axial force of the first-stage impeller is transmitted to the pump shaft through the shaft sleeve and the lower circlip structure, and is transmitted to the final-stage impeller through the upper circlip and the adjusting sleeve. The last stage impeller is floating and load-bearing to achieve the balance of axial force. The number of stages of the impeller assembly in the present invention is not limited by its own structure, and multiple groups can be connected in series, which can meet the use requirements of different stages of vertical, horizontal and inverted centrifugal pump structures.

Description of drawings

1 is a cross-sectional view of a bearing structure in the present invention;

Fig. 2 is the structural disassembly schematic diagram of the bearing structure in the present invention;

Fig. 3 is the structural representation of the impeller assembly in the present invention;

FIG. 4 is a schematic structural diagram of the first-stage impeller and the last-stage guide vane in the present invention.

Wherein, the corresponding relationship between each reference sign and component name in Fig. 1 to Fig. 4 is as follows:

1 pump shaft, 2 impeller assembly, 11 coupling, 12 spline groove, 13 prism groove, 14 spring groove, 21 impeller upper cover, 22 impeller seat, 23 impeller, 24 guide vane, 221 impeller installation position, 231 hub, 232 wheel disc, 233 wheel cover, 234 blade, 25 first stage impeller, 26 last stage guide vane, 27 lower circlip, 28 upper circlip, 29 adjusting bushing, 291 lower bushing, 292 upper bushing, 10 bearing seat , 15 inner sleeve, 16 outer sleeve.

Detailed ways

The invention provides an axial force bearing structure of a multi-stage pump, which includes a pump shaft and multiple groups of impeller assemblies. The impeller assembly includes an impeller and a guide vane floatingly arranged on the pump shaft. The first-stage guide vane is limited by the upper circlip and the adjusting shaft sleeve, so that the first-stage impeller transmits the axial force through the pump shaft to the last-stage guide vane, and is carried by the guide vane floating, realizing the balance of the axial force, which is suitable for different Multistage centrifugal pump structure. The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments of the description.

As shown in FIG. 1 and FIG. 2 , the present invention provides a multi-stage pump axial force bearing structure including a pump shaft 1 and a multi-stage impeller assembly 2 , and the multi-stage impeller assembly 2 is sleeved on the pump shaft 1 .

As shown in FIGS. 3 and 4 , the pump shaft 1 is a prismatic shaft. The upper end of the pump shaft 1 is connected with the motor shaft through a coupling 11. The top surface of the coupling 11 is provided with a spline groove 12 for connecting the motor shaft; the bottom surface of the coupling 11 is provided with a prismatic groove 13, and the pump shaft 1 The upper end of the shaft is inserted into the prism groove 13 and connected with the coupling 11 . The upper and lower ends of the pump shaft 1 are provided with snap grooves 14 .

Each group of impeller assemblies 2 includes an impeller casing composed of an impeller upper cover 21 and an impeller seat 22, and an impeller 23 and guide vanes 24 arranged in the impeller casing. The impeller seat 22 is provided with a guide vane installation position 221 , the lower end of the guide vane 24 is inserted into the guide vane installation position 221 , and the impeller 23 is arranged between the guide vane 24 and the impeller seat 22 .

The impeller 23 is a closed impeller, including a hub 231, a wheel disc 232 and a wheel cover 233 arranged on the hub 231, a blade 234 is arranged between the wheel disc 232 and the wheel cover 233, and a drain hole is arranged on the bottom surface of the wheel disc 232 , the water enters the wheel disc 232 and the wheel cover 233 through the guide vane 24, and flows out from the drain hole after being pressurized with the rotation of the vane 234. The hub 231 is adapted to the outer surface of the pump shaft 1 .

The guide vane 24 is floatingly sleeved on the pump shaft 1 , and there is a floating space with the outer side surface of the pump shaft 1 , so that the guide vane 24 can float and bear the axial force.

The first-stage impeller 25 and the last-stage guide vane 26 in the multi-stage impeller assembly are respectively arranged at the upper and lower ends of the pump shaft 1, the first-stage impeller 25 is limited by the lower circlip 27, and the last-stage guide vane 26 in the multi-stage impeller assembly The final guide vane 26 is floated on the lower end of the pump shaft 1 by the upper circlip 28 and the adjusting shaft sleeve 29 being limited.

The adjusting shaft sleeve 29 is arranged between the top surface of the last stage guide vane 26 and the bottom surface of the upper circlip 28, including a lower shaft sleeve 291 and an upper shaft sleeve 292, and the lower shaft sleeve 290 is arranged opposite to the upper end of the last stage guide vane 26, , there is a floating space with the outer side of the pump shaft 1 . The upper bushing 292 is arranged on the upper end of the lower bushing 291 and is matched with the outer side surface of the pump shaft 1 . The adjusting shaft sleeve 29 and the impeller assemblies 2 of all stages are connected in series on the pump shaft 1 , and there is an axial running distance between the adjusting shaft sleeve 29 and the impeller assemblies 2 of all stages, and the running spacing is 0.5-2 mm.

The pump shaft 1 is set on the bearing seat 10 through the shaft sleeve assembly. The bearing assembly includes two inner shaft sleeves 15 and two outer shaft sleeves 16. The inner shaft sleeves 15 are sleeved on the upper and lower ends of the pump shaft 1, respectively. Between the spring 27 and the first-stage impeller 25 , and between the upper retaining spring 28 and the coupling 11 , the inner sleeve 15 is adapted to the outer side of the pump shaft 1 . The outer bushings 16 are respectively sleeved on the inner bushings 15 and are matched with the bearing seat 10 and the inner bushing 15 at the same time.

The working principle of the present invention is as follows:

The pump shaft 1 drives the impeller assembly 2 to rotate under the drive of the motor. During the rotation process of the impeller 23, axial force is generated due to the asymmetric pressure of the upper wheel cover 233 of the impeller 23. For the first stage impeller 25, the first stage impeller 25 The lower end of the shaft is limited by the lower circlip 27, and the first-stage impeller 25 can transmit the axial force to the pump shaft 1; at the same time, because the upper circlip 28 and the adjusting sleeve 29 are arranged above the final-stage guide vane 26, and pass through the upper The last stage guide vane 26 is limited by the retaining spring 28 and the adjusting shaft sleeve 29, so that the axial force on the pump shaft 1 can be transmitted to the last stage guide vane 29, and the last stage guide vane 29 can be carried by the last stage guide vane 29 in a floating manner. For other impeller assemblies of all stages, the hub 231 on the impeller 23 of each stage is adapted to the outer side of the pump shaft 1, and the axial force on the impeller 23 can be transmitted to the pump shaft 1 through the hub 231. 24 is floating on the pump shaft 1, and the guide vane 24 can float to bear the axial force, so that for the entire multi-stage pump axial force bearing structure, there will be no axial force transmitted to the motor shaft through the pump shaft 1, so as to realize Axial force balance.

Compared with the prior art, the multi-stage pump axial force bearing structure provided by the present invention is provided with multiple groups of impeller assemblies, each group of impeller assemblies includes an impeller and a guide vane, the impeller is sleeved on the pump shaft, and the hub and the pump shaft are separated. The outer side is adapted, there is a floating space between the guide vane and the outer side of the pump shaft. The guide vane is floating on the pump shaft, which can bear the axial force generated by the rotation of the impeller, and avoid the axial force being transmitted to the motor shaft through the pump shaft. , so that the motor shaft wears due to bearing axial force, affecting its service life. Compared with the traditional floating impeller structure, in the present invention, the bearing structure of the axial force is only the hub of the impeller and the guide vane, and the radial dimension of the bearing structure is small, which can be kept low even under high-speed operation conditions. The linear speed of the impeller is too large to avoid the reduction of stage efficiency or the increase of stress caused by the increase of the airflow Mach number due to the excessive linear speed of the impeller, and prolong the service life of the impeller and the guide vane.

In the present invention, multiple groups of impeller assemblies include a first-stage impeller and a last-stage guide vane, the lower end of the first-stage impeller is limited by the lower circlip, and the upper end of the last-stage guide vane is limited by the upper circlip and the adjusting bushing , so that the first-stage impeller transmits the generated axial force to the pump shaft, and then transmits it to the last-stage guide vane through the pump shaft, and is carried by the last-stage guide vane. Or inverted multi-stage centrifugal pump, and the number of stages of the impeller assembly can be set according to actual needs to meet the use requirements of working conditions.

In the present invention, the inner shaft sleeve adopts an insert structure, and the material is wear-resistant hard alloy, which has impact resistance and local high temperature resistance, and can adapt to local friction heating and series running conditions during the start and stop of the multi-stage pump.

In the present invention, there is an axial movement space between the impellers at all levels, which facilitates the automatic adjustment of the position of the impellers by the impellers at all levels according to the pressurized medium, and avoids jamming.

The present invention is not limited to the above-mentioned best embodiment. Anyone should be aware of the structural changes made under the inspiration of the present invention, and any technical solutions that are the same or similar to those of the present invention shall fall within the protection scope of the present invention. Inside.

Claims (10)

1. a multistage pump axial force bearing structure, is characterized in that, comprises: The pump shaft is arranged on the bearing seat, and its upper end is used to connect with the motor shaft through the coupling; A multi-stage impeller assembly is sleeved on the pump shaft, the impeller assemblies at each stage include an impeller and a guide vane, and the guide vane is floating sleeved on the pump shaft; The first-stage impeller in the multi-stage impeller assembly is sleeved on the lower end of the pump shaft, and the lower end of the first-stage impeller is provided with a lower circlip for limiting; The final-stage guide vane in the multi-stage impeller assembly is floatingly arranged on the upper end of the pump shaft, and the upper end of the final-stage guide vane is provided with an upper circlip and an adjusting shaft sleeve for limiting. 2 . The bearing structure of claim 1 , wherein the pump shaft is a prism shaft. 3 . 3 . The bearing structure according to claim 1 , wherein the upper and lower ends of the pump shaft are provided with circlip grooves, and the upper circlip and the lower circlip are arranged in the circlip grooves. 4 . 4. The bearing structure according to claim 2, wherein the adjusting bushing comprises: The lower shaft sleeve is arranged opposite to the upper end of the last-stage guide vane, and there is a floating space with the outer side of the pump shaft; The upper shaft sleeve is arranged on the upper end of the lower shaft sleeve and is matched with the outer side surface of the pump shaft. 5. The bearing structure according to claim 1, wherein the pump shaft is arranged on the bearing seat through a bushing assembly, and the bushing assembly comprises: Two inner shaft sleeves are sleeved on the upper and lower ends of the pump shaft, and are respectively arranged between the lower circlip and the first-stage impeller, and between the upper circlip and the coupling. The inner shaft sleeve is adapted to the outer side surface of the pump shaft; Two outer shaft sleeves are respectively sleeved on the two inner shaft sleeves, and are matched with the bearing seat and the inner shaft sleeve at the same time. 6. The load-bearing structure of claim 1, wherein the inner bushing is an insert made of wear-resistant cemented carbide. 7. The load bearing structure of claim 1, wherein the impeller assembly further comprises: The impeller housing includes an impeller upper cover and an impeller seat. The impeller seat is provided with a guide vane installation position, the lower end of the guide vane is inserted into the guide vane installation position, and the impeller is arranged between the guide vane and the guide vane. between the impeller seats. 8. The bearing structure according to claim 1, wherein the impeller is a closed impeller, comprising a wheel hub, a wheel disc and a wheel cover arranged on the wheel hub, and the wheel disc and the wheel cover are between the wheel disc and the wheel cover. Blades are arranged between them; the hub is matched with the outer side surface of the pump shaft. 9 . The bearing structure according to claim 2 , wherein the top end of the coupling is provided with a spline groove for connecting with the motor shaft, and the bottom end of the coupling is provided with a prism groove for connecting with the motor shaft. 10 . The pump shaft is connected. 10 . The bearing structure according to claim 1 , wherein the adjusting shaft sleeve and the impeller assemblies of each stage are connected in series on the pump shaft, and the adjusting shaft sleeve and the impeller assemblies of each stage are connected in series. 11 . There is an axial run-in spacing, which is 0.5-2mm.

Images