RU2321744C1 - Birotatory generator - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: birotatory electric generator comprises at least one fastening unit, outer rotor with a birotatory hydraulic turbine and exciting magnets, and stator provided with the exciting winding and electric plug. The inner space of the stator is sealed with the bottom permeable baffle. The bottom face of the outer rotor is provided with the top permeable baffle. The driven magnets of two face clutches are arranged from both sides of the baffles. The top intermediate rotor with driven magnets is mounted concentrically to the outer rotor in the bearing mounted in the space of the inner rotor. The top inner shaft and driving magnets of the face magnetic clutches are opposite to the permeable baffles in the second space of the outer rotor. The driven magnets of the face magnetic clutches are opposite to the permeable baffles within the inner space of the stator. The driven magnets of the inner face magnetic clutch are mounted on the bottom inner shaft. The driven magnets of the outer magnetic clutch are mounted on the bottom intermediate shaft. The exciting magnets are mounted on the bottom inner shaft.

EFFECT: enhanced power.

6 cl, 2 dwg

Description

The invention relates to electric machines. Specifically, the invention is intended for a power generator for supplying downhole equipment and a transmission device for a downhole telemetry system. An electric generator converts the energy of the flushing fluid into electrical energy, which is necessary for supplying downhole navigation and geophysical instruments during drilling and the transmitter of the electromagnetic communication channel. For the telemetry system to work at great depths, an increase in the power of the transmitting device to 1 kW or more is required. To get more power with the small dimensions of the generator is very problematic.

A known alternator for powering the telemetric system in the process of drilling small diameter wells, including a fixed internal stator with a collector and an external rotor mounted on the drive shaft, equipped with electromagnets (RF patent No. 2060383, MKP ЕВВ 47/022, 47/00, priority from 21.02 .92 g). The lubrication system is a cavity between the rotor and the stator, filled with lubricating fluid.

A self-contained turbine unit (electric generator) is also intended for supplying electric energy to the telemetry system, containing a hydroturbine driven by a washing fluid stream, an oil-filled stator filled with an epoxy compound, and a rotor of an alternating current generator with permanent magnets located on the same shaft with a hydraulic turbine ( Molchanov A.A., Siraev A.X., “Borehole autonomous systems with magnetic recording”, M., Nedra, 1979, pp. 102-103).

This generator consists of a stator located inside the unit and a six-pole annular magnetic rotor made from the outside. The rotor is also a casing for the working blades of a three-stage hydraulic turbine. In front of each stage of the working blades of the hydraulic turbine, in turn, there are three stages of guide vanes assembled on the outer casing, which increases the diameter of the device. To prevent the flushing fluid from entering the generator and the bearing units, sealing devices are installed, the internal cavity of the generator is filled with transformer oil.

Due to the fact that the generator operates in the temperature range from -40 to + 130 ° С, at drilling depths up to 3500 m and more, and the oil volume changes with temperature, a compensator for pressure and thermal expansion of the lubricating fluid (oil) is introduced. The compensator for pressure and thermal expansion of the lubricating fluid is made inside the inlet fairing of the generator. It consists of two thin profile plates, one of which is convex and the other is concave. The compensator for pressure and thermal expansion of the lubricating fluid is designed to compensate for changes in the volume of oil in the oil-filled cavity of the generator under operating conditions with increasing temperature, as well as equalizing the pressure inside and outside the generator.

The disadvantages of this generator are:

- low reliability

- small resource

- large dimensions and mass of the device,

- the complexity of the design.

These shortcomings are caused, first of all, by the fact that a multistage turbine with guide vanes is used as a drive. The use of a hydraulic turbine with guide vanes as a drive places high demands on the quality of cleaning the washing liquid from fractions of drill cuttings and foreign objects, the ingress of which into the gap between the working and guide vanes of the hydraulic turbine can cause it to stop (jamming). The presence of guiding devices of a hydraulic turbine increases the diametrical dimension of the electric generator, which is undesirable when drilling wells of relatively small diameter.

The second design flaw is the complexity and unreliability of the pressure compensator and thermal expansion of the lubricating fluid. Due to the elasticity of the walls of the compensator, the pressure of the lubricating fluid is always less than the pressure of the environment. This can result in flushing fluid entering the generator’s lubrication system and in the wear of bearings, seals and other parts.

Also known generator according to US Pat. RF №2173925, the main feature of which can be considered a lubrication system. The lubrication system of this generator contains a filling device at its front end, a cavity between the external rotor and the stator, filled with lubricating fluid, and a pressure compensator and thermal expansion of the lubricating fluid located on the side of the generator mounting device, made in the form of a piston mounted with axial movement and seals mounted inside the piston with the possibility of axial movement with it. The disadvantage of this device is the difficulty of filling the system with lubricating fluid and a low seal life.

Known power generator telemetry systems according to St. RF №34638.

This electric generator contains a filling device in its front part, a cavity between the external rotor and the stator filled with a lubricating fluid, and a compensator for pressure and thermal expansion of the lubricating fluid located on the side of the generator mounting device, made in the form of a piston mounted inside the rotor with axial movement , and the seal installed in turn inside the piston with the possibility of axial movement with it, the piston is made with the possibility of drainage lubricating fluid in a fully charged position in the gap between the rotor and the generator mount.

The disadvantage of this lubrication system is that due to the combination of the functions of the compensator and the seal, their life is reduced.

Known generator for St. RF №13123, which contains a rotor with a turbine, a stator, a mounting unit and a reservoir for the reserve supply of lubricating fluid, made in the form of a cup made in the front of the generator with a spring-loaded piston installed inside and a refueling device. The generator and turbine are significantly distant from each other in the axial direction and are separated by a magnetic coupling, which increases the dimensions of the generator and reduces the reliability of the lubricant.

A known generator according to the patent of the Russian Federation for invention No. 2264537, a prototype comprising a housing with field windings, a mount, a rotor with a shaft, magnets and a turbine mounted through bearings in the housing, and a reservoir for a reserve supply of lubricating fluid in the form of a cup made in front generator with a spring-loaded piston installed inside and a refueling device, characterized in that at least one front bearing is mounted in a sleeve that is centered in the protruding part of the housing, closed on the other Torons axis fixed against rotation and having an annular groove for winding and a cylindrical protrusion in the inner bore of which is mounted on at least one rear bearing and the inside shaft provided with a through axial aperture. An adjustment washer is installed between the front bearing and the rotor. Field windings are installed in the housing and are fixed with pins against bias. The spring is partially placed inside the piston. The filling device is made in the form of a valve installed in the stem channel, closed by a plug. The filling device is made in the form of a valve installed in the stem channel, closed by a plug.

Disadvantages - insufficient power of the generator with limited diametrical dimensions.

The tasks of its creation are to increase power while reducing the diametrical dimensions and weight of the generator.

The solution to this problem was achieved due to the fact that the rotational generator, containing at least one attachment point, an external rotor with a rotational hydroturbine and field magnets, a stator with a field winding and an electrical connector, is characterized in that the internal stator cavities and the outer rotor is sealed with magnetically permeable partitions, on both sides of which are driven magnets of two end couplings, while concentrically to the outer rotor, on bearings made inside him, installed the upper intermediate rotor with driven magnets, the upper inner shaft, the driving magnets of the end magnetic couplings are installed against the magnetically permeable partitions in the inner cavity of the outer rotor, the driven magnets of the end magnetic couplings are installed against the magnetically permeable partitions in the inner cavity of the stator, while the driven magnets of the inner end magnetic the couplings are mounted on the lower inner shaft, and the driven magnets of the external magnetic coupling are mounted on the lower intermediate shaft, the magnets in Excitations are mounted on the lower inner shaft. Hydroturbines are installed side by side in front of the generator. The wires from the winding to the electrical connector pass through the holes made in the stator. The inner cavity of the magnetic coupling is filled with a lubricating fluid, and the inner cavity of the field coil and field magnets is filled with a compensating fluid. The hole for filling the lubricant is made from above, and the electrical connector is from below. The electrical connector is coaxial.

The proposed technical solution has novelty, inventive step and industrial applicability, i.e. all the criteria of the invention. The novelty is confirmed by patent research, the inventive step - a new layout of the generator. For the manufacture of all nodes of the electric generator, scarce materials and newly developed technologies are not required, which guarantees industrial applicability.

The invention is illustrated in figure 1 ... 2, where:

figure 1 shows the assembly drawing of a biotational generator,

figure 2 shows the arrangement of hydraulic turbines.

A biotic generator designed to power the downhole equipment is installed in the drill pipe string or in the casing and contains at least one device for attaching the generator 1 to the stator 2. In the device for attaching the generator 1, holes “B” are made for drilling fluid passage.

The biirotational electric generator contains an external rotor 3 with a rear hydraulic turbine 4 and an internal rotor 5 with a front hydraulic turbine 6, i.e., the hydraulic turbine is made of a two-stage biotic. The front hydraulic turbine 6 has obliquely mounted flat blades mounted at an angle of 20 ... 45 °, and the blades of the hydraulic turbine 4 are made profiled in order to more effectively operate the pressure drop on the hydraulic turbines, because the execution of both turbines the same would not allow the difference in the second flow to work, i.e. rear turbine 4.

The stator 2 has an electrical connector 7 at the bottom, and an excitation winding 8 is installed inside the stator 2.

The generator has two magnetically permeable partitions - the upper 9 and lower 10, which separate the external rotor 3 from the stator 2 and create an leaky cavity of the external rotor "B" and the internal cavity of the stator "G". On both sides of the non-magnetic partitions - the upper 9 and lower 10 are the magnets of two end magnetic couplings, namely: internal and external, specifically driven magnets of the internal and external couplings, respectively 11 and 12. Magnets 11 are installed on the upper shaft 13, and magnets 12 are mounted on the rotor 5, which is mounted on the bearing 14 in the glass 15. The sealed cavity of the rotor "D" is filled with lubricating fluid. The lubricating fluid of the cavity "D" is filled through the channel "E", closed during operation with screw 16. The cavity "B" communicates with the external environment through the hole "G". Inside the stator 2 at its upper end near the non-magnetic partition 9, the driven magnets of the inner and outer end couplings 16 and 17, respectively, are installed. Excitation magnets 19 are installed on the lower shaft 18, and an excitation winding is installed on the lower intermediate shaft 20. The lower shaft 18 is installed in the bearings 21 and 22, and the intermediate shaft 20 on the bearings 21 and 23. The lower shaft 19 has a thrust collar 24, under which current collector rings 25 are installed, with which the current collectors 26 are in contact. The wires 27 are connected through the holes “D” to the electrical connector 7 and sealed with compound 28. To fill the cavity “G” with compensating liquid, the hole in the stator of the generator 2 is closed by a plug 29.

Hydroturbines 4 and 6 are installed side by side, at a distance of 2 ... 5 mm from each other in the front of the generator, for a more complete operation of the pressure drop due to the profiling of the turbine blades 4 and 6 with different angles of installation of the blades. Hydroturbine 6 is simultaneously a nozzle apparatus for hydroturbine 4 (figure 3). This allows you to abandon the use of nozzle devices, which will simplify the assembly of the generator and reduce its diametrical dimensions and weight of the generator.

The internal stator cavity "G" and the sealed cavity "D" are filled with lubricating fluid. The hole "E" for filling the sealed cavity "D" with lubricating fluid is made in the upper part of the inner rotor 5 and is closed by a screw 16.

The cavity "G" in which the excitation winding 8 and the exciting magnets 8 are located is filled with a compensating liquid. The compensating liquid has a specific volume expansion coefficient equal to the specific volume expansion coefficient of the metal from which the stator 2 is made, while the compensating liquid does not have to have lubricating properties.

On the stator 2 in the lower part there is a filling hole for the compensating liquid, closed by a screw 29.

When the generator is operating, the drilling fluid passes through the hydraulic turbines 6 and 4, which begin to rotate with the rotor 3 and the upper inner shaft 13 in different directions.

The first flow turbine 6 will act as a nozzle apparatus for the second flow turbine 4. This will simplify the assembly of the generator, abandon the use of guide vanes and increase the efficiency and power of the turbine. It also became possible to significantly reduce the diametrical dimensions of the generator or increase its power by about 2 times with the same dimensions and weight. This will allow the design of downhole tools for small diameter drill and casing. The use of wires for the transmission of electrical energy located in the “I” holes of stator 2 will allow significant power to be output using sliding current collectors 26. A generator with a downhole telemetry system downhole device can be installed in a drill or casing assembled from pipes up to 10-12 m long , i.e. the length limit is not critical, unlike the diameter limit. Layout diameter: generator-downhole tool is strictly limited by the diameter of the string. Electricity is transmitted through wires 27 from the field winding 8 to the electrical connector 7. It is preferable to make the electrical connector 7 coaxial, this will make it possible to abandon the angular orientation of the electric generator inside the drill string or casing when it is docked with the downhole tool (Figs. 1-3 are not shown )

The application of the invention allowed:

1. Significantly reduce the diametric dimensions and weight of the birobotative electric generator through the use of the birobative turbine and increase its length by the length of the magnetic coupling.

2. To increase the power and voltage at the electrical terminals of the generator through the use of a biotic turbine.

3. Significantly increase the service life of the supports due to the use of multi-bearing schemes, reducing the diameter of two seals to the minimum possible, ie to the shaft diameter and to minimize the sliding speed of the upper seal on the shaft relative to the shaft to almost zero.

4. To reduce the imbalance of the rotor of the birotative electric generator by reducing their diameter by 1.5-2.0 times.

5. To increase the reliability of sealing the cavity of the birobotative electric generator by separating the oil cavity “D” from the cavity with the compensating liquid “G” with a volume coefficient of thermal expansion equal to the volume coefficient of thermal expansion of the metal from which the stator is made, and failure of the expansion valve, without which electric generators in the face are usually not used.

6. To simplify the design of the birobotative electric generator, due to the rejection of the use of turbine guides and the maximum simplification of the seal design.

7. To simplify the assembly and disassembly of the birobotative electric generator through the implementation of a modular design and the use of a coaxial electrical connector.

8. Improve the maintainability of the birotative electric generator due to the extremely simple design, the minimum number of parts and the simple configuration of all parts.

Claims (6)

1. A rotational electric generator for powering the downhole tool, comprising at least one attachment point, an external rotor with a biotational hydraulic turbine and field magnets, a stator on which a field coil and an electrical connector are installed, characterized in that the internal cavity of the stator is sealed with a lower magnetically permeable partition, and on the lower end of the outer rotor there is an upper magnetically permeable partition, on both sides of which there are driven magnets of two end couplings, while like the outer rotor, the upper intermediate rotor with driven magnets is mounted on the bearing in the first cavity of the inner rotor inside it, the upper inner shaft, the driving magnets of the end magnetic couplings are installed against the magnetically permeable partitions in the second cavity of the outer rotor, the driven magnets of the end magnetic couplings are installed against magnetically permeable partitions in the inner cavity of the stator, while the driven magnets of the internal mechanical coupling are mounted on the lower inner shaft, and e outer magnets of the magnetic clutch are mounted on the lower intermediate shaft, the driving magnet mounted on the lower inner shaft. 2. Biirotational electric generator according to claim 1, characterized in that the turbines are installed side by side in front of the generator. 3. The biirotational electric generator according to claim 1 or 2, characterized in that the wires from the winding to the electrical connector pass through holes made in the stator. 4. The biotic generator according to claim 1 or 2, characterized in that the internal cavity of the magnetic coupling is filled with a lubricating fluid, and the internal cavity of the field coil and field magnets is filled with a compensating liquid. 5. The biotic power generator according to claim 1 or 2, characterized in that the opening for filling the lubricating fluid is made from above, and the electrical connector is from below. 6. Biirotational electric generator according to claim 5, characterized in that the electrical connector is made coaxial.

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