RU35851U1 - SUBMERSIBLE CENTRIFUGAL PUMP - Google Patents

Description

Submersible Centrifugal Pump

The technical field to which the utility model relates.

The utility model relates to the field of oil production equipment, in particular to submersible centrifugal pumps designed for wells with high mechanical impurities and gas content

State of the art

The prior art submersible centrifugal pump containing a shaft, impellers, guide vanes with a shoulder on which the impeller rests, to reduce the friction force between the impeller and the guide vane collar, due to the axial force acting on the impeller, the impeller is equipped with a support washer from anti-friction material, for example textolite. (A.A. Bogdanov Submersible centrifugal pumps for oil production, Moscow, ed. Nedra, 1968, pp. 38-40, Fig. 31).

The disadvantage of this submersible centrifugal pump is that, as the washers wear, the impellers move along the shaft. Textolite washers undergo intensive wear, which leads to a disruption of contact between the impeller support washer and the guide vane collar, and contact may occur between the impeller itself and the guide vane collar, in case of complete wear of the support washers, which in turn leads to a sharp decrease in reliability pump operation, and ultimately to an accident.

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MPK7 F04D13 / 00 F04D13 / 10

The closest to the claimed utility model in terms of the set of essential features and the technical result achieved is a submersible centrifugal pump containing a shaft, impellers with support washers and forming step groups, guiding devices, each wheel mounted on the shaft with the possibility of axial movement, each group the steps are equipped with an axial support, which is made of material with increased wear resistance (see utility model RU9905U1 class F04D 13/10 publ. May 6, 1999).

The disadvantage of this pump is that the impellers in the group of sequentially arranged stages are located on the shaft directly with their hubs directly in contact with each other, which does not allow the use of support washers in each impeller. The supporting washers are not only axial bearings, but also sealing elements in each stage, which exclude fluid flow through the gap seal.

The slotted seal during wear of the pump is subject to wear, especially in wells with increased mechanical impurities, as a result of which fluid leaks through this slotted seal, which in turn leads to a sharp decrease in the efficiency (efficiency) of the pump, especially at low flow rates.

This design allows you to transfer axial force from the groups of impellers to the reinforced axial support of one stage. However, the initial, direct contact of the hubs of several impellers does not allow reliable gap sealing of the steps from the bottom of the wheel disk at the end of the guide vane collar for technological reasons, since this requires more accurate execution of all contacting surfaces: hubs, thrust washers, etc. .

The problem to which the proposed utility model is directed is to reduce the effort on the supporting washers of the impellers and to reduce their wear, as well as to create a reliable seal in the contact of the supporting washer - guide;

Dry; utility model

The technical result, the achievement of which the claimed solution is directed, is to increase the reliability of the pump and increase its service life.

The technical result achieved is achieved due to the fact that the submersible centrifugal pump, containing the shaft, on which impellers are mounted with hubs with the possibility of axial movement, equipped with a supporting washer and forming step groups, guiding devices made with a shoulder, step groups are equipped axial support, consisting of a supporting washer of the impeller and a shoulder of the guide apparatus, which are made of material of increased wear resistance, and the hubs of the impellers are located on the shaft with the rear axial clearances. The height of the supporting washer of the impeller of the last stage in each group of stages exceeds the sum of the values of all the specified axial clearances between the hubs of the impellers in the group. The shaft is configured to transmit axial force to the first stage in at least one group of wheels.

A distinctive feature of the claimed utility model is that the hubs are located on the shaft with predetermined axial clearances. The presence at the first stage of each group of impellers of an axial support (supporting washer - shoulder of the guide apparatus) made of a material with wear resistance higher than the wear resistance of the remaining washers of the workers, eliminates its intensive wear. Friction pair can be

made, for example, of ceramic or siliconized graphite. During the operation of the pump, there will be a gradual wear of the supporting washers of the impellers of all stages in each group, except for the first stage, and as the supporting washers wear, the wheel hubs will mix along the shaft, due to the available; their specified axial clearances between them and the axial force will be redistributed by loading the first steps through the contact of the wheel hubs. The redistribution of effort will reduce the force on the support washers, which will reduce the wear of the support washers themselves. In addition, during running-in of contacting surfaces, for example, supporting washers of impellers with a collar, it, the hubs of the impellers between each other, provide a reliable seal in contact between a supporting washer and a collar of its guiding device.

The wear of the support washers will occur from the minimum value at the stage following; to it beyond the stage, where there is a friction pair of material with increased wear resistance, to the calculated maximum value at the last stage.

When conducting a search on patent and scientific and technical information, no solutions were found that contained the entire totality of the proposed features, which allows us to conclude that the claimed device meets the criterion of "novelty.

List of drawings

Figure 1 presents the initial position of the impellers of the submersible

centrifugal pump FIG. 2 shows the position of the impellers during operation

submersible centrifugal pump.

The submersible centrifugal pump comprises a shaft (1), onto which impellers (3) are mounted via hubs (2) with the possibility of axial movement and forming impeller groups. To reduce the friction force between the impeller (3) and the shoulder (5) of the guide apparatus (6), due to the axial force acting on the wheel and reduce leakage through the slotted seal, the impellers (3) are equipped with a support washer (4) made of antifriction material, for example, textolite. The impellers (3) through the supporting washers (4) interact with the shoulder (5) of the guide apparatus (6). The supporting washer (7) of the impeller (3) of the first stage in each group of wheels and the insert (8) made in the shoulder of the guide apparatus (6) or the shoulder of the guide apparatus are made of material whose wear resistance is higher than the wear resistance of the material from which the bearings are made washers (4) of the remaining impellers. The hubs (2) of the impellers (3) are located on the shaft with predetermined axial clearances (a). The height (A) of the support washer (4) of the impeller of the last stage in each group of steps exceeds in its value the sum of the values of the axial clearances {a} between the hubs of the impellers in the group, (see figL).

The proposed device operates as follows.

During the operation of the submersible centrifugal pump, axial forces act on the impellers (2). The wheel is supported by the lower disk on the shoulder of the guide vane. When the supporting washers (4) of the impellers (3) interact with the shoulder (5) of the guide vanes (6), the washers (4) wear out. When the impeller (3) of the first stage interacts with the guiding apparatus (6), a friction pair (supporting washer - collar) is formed at the contact point, which will be less intense

wear than the friction pair formed in the remaining steps. This is due to the fact that the insertion of the shoulder of the guide vane (8) or the collar of the guide vane (6) and the thrust washer (7) are made of material whose wear resistance is higher than the wear resistance of the material from which the thrust washers of the other impellers are made (see Fig. 2 )

Therefore, wear of the supporting washers (4) of the impellers will occur from the stage following the stage, the friction pair of which is made of a material whose wear resistance is higher than the wear resistance of the material of the supporting washers of the remaining impellers. The amount of wear of the support washer will be equal to the value of the specified axial clearance between the hub of the first stage and the next stage (see figure 2)

As a result of the wear of the support washer (4), the hub moves along the shaft and comes into contact with the hub of the previous stage. The force from the axial support to move to the adjacent hubs and will be perceived as the first stage. Further, as you move away from the first stage, the wear value of the support washers will increase by the amount of axial clearances between the hubs.

As the washers wear out, the axial force acting on the impellers (3) in each group of stages will be perceived not by the guiding devices (6), but by the adjacent hubs (2) of the impellers (3) and the first stage, which reduces the force on the supporting washers during operation, and reduces wear on the washers.

Since the group of steps consists of several impellers, the axial clearances (a) between the hubs of the impellers are selected in such a way that, if the hubs of all the impellers are in contact in the group, the support washer (4) of the last impeller has a certain value, which ensures that contact is not made the collar of the guide apparatus directly with the impeller and the exclusion of fluid flow in the contact support washer - collar. The height (A) of the support shaft is selected based on the following relationship: A 2, where i is the number of gaps in the group, a is the value of the axial clearance, 4- the final number of axial gaps in the group Thus, the support washer and the collar of the guide vane or an insert made in a collar of the first step in each group of steps of a material whose wear resistance is higher than the wear resistance of the material from which the supporting washers of the other wheels are made and the placement of the hubs on the shaft with predetermined axial clearances allows reducing the force on the supporting washers, since the force from the axial bearings is redistributed as the bearing washers wear, loading the axial support of the first stage by successive contact of the impeller hubs, while eliminating the complete wear of the impeller washers. Reducing the wear of the support washers will improve the reliability of the pump and increase its service life. The location of the impeller hubs on the shaft with the initial defined axial clearances of a certain size, provides during the operation of the pump a gradual running-in of contact surfaces, for example, a supporting washer and a collar of the guide apparatus. Gradual running-in provides a reliable seal in the contact of the support washer - the shoulder of the guide apparatus. The specified axial clearance is ensured by the execution of the hubs of the working wheels in more accurate sizes. It is also advisable to perform the shaft with the possibility of transmitting the shearing force acting on the shaft to the first stage, at least in the bottom group of wheels. Then the axial force acting on the shaft will be sensed by this group of steps and transmitted to the pump casing.

unloading either the hydroprotection shaft, or eliminates the axial support of the pump shaft.

The proposed solution meets the criterion of "industrial applicability, since the manufacture of a pump is possible using sushi, existing; their means of production using well-known technologies.

Claims (3)

1. Submersible centrifugal pump containing a shaft on which impellers are mounted axially movable with hubs, equipped with a support washer and forming groups of steps, guiding apparatus made with a shoulder, the groups of steps are provided with an axial support consisting of a support washer of the impeller and inserts located in the shoulder of the guide vane, which are made of material of increased wear resistance, characterized in that the impeller hubs are located on the shaft with predetermined axial clearances ramie. 2. The submersible centrifugal pump according to claim 1, characterized in that the height of the supporting washer of the impeller of the last stage in each group of stages is greater in magnitude than the sum of all the specified axial clearances between the hubs of the impellers in the group. 3. The submersible pump according to claims 1 and / or 2, characterized in that the shaft is configured to transmit axial forces acting on the shaft to the first stage of at least one group of wheels.