RU2478836C1 - Flexible coupling - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: invention is designed for flexible tight connection of component parts of motor-driven centrifugal pump units (MCPU). Two housings of the coupling are connected via a hollow spherical ring with pins. A gap between the spherical ring and housings of the coupling are sealed with sealing elements. Shafts connected to each other with two articulated couplings (AC) equally spaced from the centre of the spherical ring are arranged inside the housings. AC include splined forks, cross pieces (C) with spherical surfaces and pins of C, by means of which C are connected to forks. Spherical surface of each C has a centre on intersection of the shaft rotation axis with axis of C pin. Splines of shafts relative to splines of forks have the possibility of restricted axial movement. Edges of shafts are borne against spherical surface of C.

EFFECT: providing the possibility of using a flexible hinge connection in MCPU, in which pump sections have no their own axial supports, and axial load on shafts of the pump sections is taken only with an axial bearing located in a seal section of a submerged electric motor, by transferring an axial load and a torque moment through shafts and AC of shafts, as well as reduction of bending stresses in MCPU at their operation in inclined and curved wells.

3 cl, 3 dwg

Description

The invention relates to petroleum engineering and can be used in installations of electric centrifugal pumps for oil production from directional and deviated wells.

It is known to install submersible centrifugal pumps, comprising a pumping unit in the form of modular sections interconnected by a movable device made in the form of a base sleeve, connected at one end to a housing of one modular section of a pumping unit, and to a spherical segment with an elastic sealing element on the other end and with a stopper by means of a threaded connection, a union nut with a thread connecting the base sleeve to another modular section, shafts interconnected by couplings providing them Glowe offset (RF Patent 2218481, MPK7 F04D 13/10, 29/62, publ. 22.08.2001).

The disadvantage of this installation of submersible centrifugal pumps is the inability to transmit the axial load from the shaft of the upstream pump section to the shaft of the downstream pump section or the hydroprotection shaft of the submersible motor, which makes it impossible to use this device in electric drive centrifugal pump installations in which the pump sections do not have axial bearings, and the axial load on the shafts of the pump sections is perceived only by an axial bearing located in the hydraulic protection of the submersible electrode wiggler. In addition, the disadvantages of transmitting torque through the ropes: uneven rotation of the driven end of the shaft at significant loads, relatively small and uneven durability, significant fluctuations in torsional stiffness of the same shafts. The indicated uneven rotation also reduces the efficiency of the centrifugal vane pump.

The closest in technical essence and the achieved result to the claimed object is a flexible swivel coupling containing two housings interconnected by means of a ring with a spherical outer surface, made with a cross of fingers, by means of which the ring is connected to the housings, an intermediate shaft with two articulated couplings, equidistant from the center of symmetry of the cross (RF patent 2230233, IPC7 F04D 29/62, 13/10, publ. 09/11/2002).

The disadvantage of this flexible swivel coupling is the inability to transmit the axial load from the shaft of the upstream pump section to the shaft of the downstream pump section or the hydroprotection shaft of the submersible motor, which makes it impossible to use this device in electric drive centrifugal pumps in which the pump sections do not have axial bearings, but the axial load on the shafts of the pump sections is perceived only by an axial bearing located in the hydraulic protection of the submersible motor , Sealing the internal cavity of the flexible hinge is provided by a sealed coupling corrugated metal hose, which reduces the reliability of the device due to leakage of hose abrasion from interacting with the inner wall of the production tubing when the device is descending the borehole.

The objective of the invention is the ability to use a flexible swivel in the installation of electric centrifugal pumps, in which the pump sections do not have axial bearings, and the axial load on the shafts of the pump sections is perceived only by an axial bearing located in the hydraulic protection of the submersible motor, by transmitting the axial load and torque through the shafts and hinged shaft couplings, as well as reducing bending stresses in electric drive centrifugal pump installations by bending the coupling housings flexibly relative to each other during their operation in directional and deviated wells.

The problem is solved in that in a flexible coupling containing two housings connected to each other by means of a ring with a spherical outer surface made with a cross of fingers, by means of which the ring is connected to the housings, an intermediate shaft with two hinged couplings located inside the cross is equidistant from the center symmetry of the cross and designed for articulating the shafts of the sections of the submersible electric pump, each of the articulated couplings located between the intermediate shaft and the shafts of the sections of the submersible the pump is made with the possibility of transmitting axial load and includes forks connected to the shafts by slots having the possibility of axial movement, a cross made with a spherical surface having a center at the intersection of the axis of rotation of the shaft with the axis of the finger of the cross, and shafts abutting against the spherical surface of the cross . In addition, the ends of the shafts, abutting against the spherical surface of the cross, can have a concave spherical, with a radius of the sphere not more than the radius of the spherical surface of the cross, or a concave conical surface. Also between the ends of the shafts and the spherical surface of the crosspiece can be placed sleeve with a spherical or conical surface on the side of the cross.

Figure 1 shows a General view of the coupling flexible. Figure 2 shows an embodiment of the articulated coupling. Figure 3 shows an embodiment of the articulated coupling.

The flexible coupling consists of housings 1 and 2, connected by a ring 3 with a spherical outer surface by fingers 4 and a sealing element 5, shafts 6 and 7, connected on one side to the shafts of the sections of the submersible electric pump (not shown), and on the other hand to the intermediate shaft 8 articulated couplings consisting of forks 9, crosspieces 10 with spherical surfaces, pins 11 and fingers of crosspieces 12. It is possible to install bushings 13 with a spherical or conical surface.

When the device is operating in a directional or curved well, as part of an electric drive centrifugal pump installation, mounted either between the pump sections or between the hydraulic protection of the electric motor and the pump input module, the axes of the housings 1 and 2 are placed at an angle relative to each other due to their articulated hermetic connection, formed by a ring 3, fingers 4 and a sealing element 5. The axial load from the shaft 6 is transmitted to the spherical surface of the spider 10 located in the upper hinge coupling, from which is transmitted to the intermediate shaft 8 and then through another crosspiece 10. located in the lower hinged coupling, to the shaft 7. To reduce the specific pressure between the spherical surface of the crosses 10 and the ends of the shafts 6, 7 and 8, abutting against the crosses 10, the ends of the shafts 6 , 7 and 8 may have a concave spherical, with a radius of the sphere not greater than the radius of the spherical surface of the cross 10, or a concave conical surface.

The torque from the shaft 7 is transmitted through a spline connection to a swivel coupling, including forks 9, fingers of the spider 12 and crosspiece 10, then to the intermediate shaft 8, from which it is transmitted through another similar swivel coupling to the shaft 6. The spline connection of the forks 9 to the shafts 6, 7 or 8 has the possibility of limited axial movement, because the pins 11, rigidly fixed in the forks 9, can move relative to the shafts 6, 7 or 8 within the grooves 14, which excludes the transmission of axial load through the forks 9 and, accordingly, through the fingers of the crosses 12. An installation option between the ends of the shafts 6, 7 and 8 and the spherical surfaces of the crosses 10 of the bushings 13 having conical (Figure 2) or spherical (Figure 3) surfaces from the side of the crosses 10.

Claims (3)

1. The coupling is flexible, comprising two housings interconnected by means of a ring with a spherical outer surface made with a cross of fingers, by means of which the ring is connected to the housings, an intermediate shaft with two articulated couplings located inside the cross, equidistant from the center of symmetry of the cross and designed to articulation of the shafts of the sections of the submersible electric pump, characterized in that each of the articulated couplings located between the intermediate shaft and the shafts of the sections of the submersible pump and with the possibility of transmitting axial load, it also includes forks connected to the shafts by splines that are capable of axial movement, a cross made with a spherical surface having a center at the intersection of the axis of rotation of the shaft with the axis of the finger of the cross, and shafts abutting against the spherical surface of the cross. 2. The flexible coupling according to claim 1, characterized in that the ends of the shafts abutting against the spherical surface of the cross have a concave spherical with a radius of the sphere not greater than the radius of the spherical surface of the cross or a concave conical surface. 3. The flexible coupling according to claim 1, characterized in that between the ends of the shafts and the spherical surface of the cross is a sleeve with a spherical or conical surface on the side of the cross.

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