RU102071U1 - MULTI-STAGE CENTRIFUGAL PUMP - Google Patents

Abstract

 A multistage centrifugal pump, the pump part of which contains a set of stages, including metal cages and working bodies assembled on a shaft, for fixing which radial bearings are used during operation, and seals on the pressure part of each stage, the rotor is included in the electric motor, for fixing which relative to the stator, radial plain bearings are used, characterized in that the outer bushings of the plain bearings and the seal on the pressure part are made of polyurethane and internally The surface of the clips is coated with a layer of polyurethane.

Description

The utility model relates to the field of pump engineering, in particular, to the design of a centrifugal multistage borehole electric pump, which can be used, for example, for pumping industrial and drinking water with a high content of solids.

Known multistage borehole centrifugal electric pump type ETsV4- ... ETsV12 - for pumping water, the pump part of which contains a set of stages, including clips and working bodies assembled on a shaft, for fixing which during operation rubber-metal radial plain bearings and rubber seals on the pressure part are used each stage, and the rotor is included in the electric motor, for fixing which relative to the stator rubber-metal radial plain bearings are also used. (See Electric pump ЭЦВ4- ... ЭЦВ12. Passport АМТ 3.246.001 Substation, Livny, OJSC "Livnynasos", АМТЗ.246.001ТУ).

The disadvantage of this pump is that the working life of parts exposed to intense exposure to a stream of water containing solid solids (sand) is relatively small. In practice, even under good operating conditions, they retain their performance, usually 1.5-2 years, since the rubber from which the radial bearings and seals are made, and the metal of the cages on the inner surface quickly wear out.

The task that the claimed technical solution solves is to eliminate this drawback, increase the resource and increase the reliability of the pump.

The problem is solved in that the outer sleeve of the bearing, the seal (seal sleeve) on the pressure part of the stage instead of rubber are made of polyurethane. The inner surface of the clips is also coated with a layer of polyurethane. The resource of these parts increases due to the increased wear resistance of polyurethane compared with rubber or metal.

Despite the higher prices of the proposed material compared to rubber, the use of polyurethane is economically advantageous, because it increases the overall resource of the unit.

In the drawings, in section, for example, a multistage centrifugal pump (FIG. 1) and a water-filled electric motor (FIG. 2) are shown.

Figure 1 - multistage centrifugal pump, for example, a vertical design with "floating" impellers.

A multistage centrifugal pump is a design consisting of fixed and moving (rotating) parts and assemblies during pump operation. Fixed parts and assemblies include: base 1, cages 2, coated on the inner surface with a layer of polyurethane, guiding devices 3, sealing sleeves 4 made of polyurethane, interstage disks 5 with locking pins 6, bearing housing 7, outer sleeve of a radial plain bearing 8 made of metal-reinforced polyurethane, couplers 9, valve 10 and valve body 11. The movable (rotating) part of the pump consists of a shaft 12, on which an internal bearing bushing is fixed to the key 14 on the key 14 Slides 15 and heel 16, on the keys 17 fixed impellers 18 and thrust bushings 19. The lower end of the shaft is connected to the rotor of the electric motor by a rigid coupling 20 fixed to the shaft by a key 21.

Figure 2 - asynchronous water-filled electric motor vertical design.

The electric motor also consists of fixed and movable (rotating) units and parts during operation. Fixed parts and assemblies include: a bottom 1 with a spherical support and pins pressed into it, a thrust bearing 2 made of polyurethane reinforced with metal, lower studs 3 with spring nuts and washers, a lower ring 4, a lower shield 5, an external sleeve fixed in it lower plain bearing 6, made of metal-reinforced polyurethane, stator housing 7, placed in it stator 8, consisting of a set of dynamical steel plates, pressure rings 9, stator winding 10, shield top 11, external bushings fixed therein their sliding bearing 12 made of polyurethane, reinforced with a metal top ring 13, the upper pins 14 with bolts and spring washers. Movable (rotating) nodes and parts include: shaft 15, a rotor 16 mounted on it, made of a set of dynamo steel plates, balancing rings 17, internal bushings of sliding bearings 18, heel 19, mounted on the shaft with a key 20 and a retaining ring 21.

The pump unit presented for example works as follows.

The electric pump is lowered into the well and put into operation. The electric motor is located at the bottom of the unit. The torque from the electric motor through the coupling 20 (Fig. 1) is transmitted to the pump shaft 12 (Fig. 1) with a set of stages containing the impellers 18 (Fig. 1). The pumped liquid enters the space between the disks of the rotating impellers 18 (Fig. 1) and, under the action of centrifugal forces, moves from their center to the periphery. At the exit of each impeller 18 (FIG. 1), the fluid flow enters the channels between the arcuate protrusions of the guide apparatus 3 (FIG. 1), the interstage disk 5 (FIG. 1) and the cage 2 (FIG. 1), changes the direction of movement from the pressure part of the previous impeller 18 (figure 1) to the suction part of the next impeller 18 (figure 1).

An asynchronous electric motor works when AC enters the stator winding due to the interaction of the magnetic fields of the stator 8 (figure 2) and the rotor 16 (figure 2).

When connecting the pump and the electric motor to the unit, the lower part of the pump shaft 12 (Fig. 1) is connected to the rotor shaft of the electric motor 15 (Fig. 2) using a rigid coupling 20 (Fig. 1). During operation of the electric pump, both shafts with parts and assemblies attached to them turn into a system with a single axis of rotation.

Tests have shown that the claimed multistage centrifugal pump has improved technical and operational characteristics. It can work on pumping water with a high content of mechanical impurities.

Claims (1)

A multistage centrifugal pump, the pump part of which contains a set of stages, including metal cages and working bodies assembled on a shaft, for fixing which radial bearings are used during operation, and seals on the pressure part of each stage, the rotor is included in the electric motor, for fixing which relative to the stator, radial plain bearings are used, characterized in that the outer bushings of the plain bearings and the seal on the pressure part are made of polyurethane and internally The surface of the clips is coated with a layer of polyurethane.