RU2334099C1 - Power generator for well equipment - Google Patents

Abstract

FIELD: mining; electrics.

SUBSTANCE: generator includes protection case and at least one mounting unit, electric connector, rotor installed on shaft with turbine, stator, exciter winding, and permanent magnets. Additional rotor and contact-free power transfer device in the form of primary and secondary windings are mounted on supports on the shaft. One of the windings is mounted on the turbine case connected to the main rotor, while the other one is mounted on the additional rotor. Stator and shaft are divided into upper and lower parts. Upper and lower shaft parts are connected. Exciter winding is mounted at the upper shaft part. Permanent magnets are installed inside the main rotor concentrically to the exciter winding. Primary winding of contact-free power transfer device is mounted at the lower shaft part, the secondary winding being mounted inside the lower stator part concentrically to the primary one. Primary exciter and windings are connected electrically to provide contact-free power transfer. Secondary winding is connected to the electric connection by electric wires passing through a hole in the lower stator part and led outside through a sealing plug.

EFFECT: reduced diametric dimensions and weight of generator.

2 cl, 1 dwg

Description

The invention relates to electric machines. Specifically, the invention is intended for a downhole power generator. The generator converts the energy of the flushing fluid into electrical energy, which is necessary to power the downhole navigation and geophysical instruments during drilling and the transmitter of the electromagnetic communication channel.

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), also designed to power the telemetry system, contains a hydraulic turbine driven by a wash 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, prototype.

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 the fluid in the fully tucked position to the gap between the rotor and the alternator mounting assembly.

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.

The disadvantage is the rapid wear of the rolling bearings due to high loads, vibration and the possibility of penetration of the drilling fluid.

The tasks of its creation are to reduce the diametrical dimensions and weight of the generator.

The invention relates to electric machines. Specifically, the invention is intended for a downhole power generator.

The tasks of its creation are to reduce the diametrical dimensions and weight of the generator.

The solution to this problem was achieved in the power generator of the downhole equipment, containing a protective housing and at least one attachment point, an electrical connector mounted on the shaft of the rotor with a turbine, a stator, permanent magnets and an excitation winding, so that additional supports are installed on the shaft on the supports a rotor and a device for contactless transmission of electricity, made in the form of primary and secondary windings, one of which is installed on the turbine housing, which is connected to the main rotor, and the second on the additional mouth In this case, the stator and the shaft are made of two parts - the upper and lower parts, the upper and lower parts of the shaft are interconnected, the field winding is mounted on the shaft in its upper part, permanent magnets are installed concentrically with it inside the main rotor, and the lower part of the shaft is installed primary winding is a device for non-contact transmission of electricity, and a secondary winding is installed concentrically to it inside the lower part of the stator, while the primary and excitation windings are electrically connected for non-contact transmission electricity, and the secondary winding is connected to the electrical connector by electric wires passing inside the hole made in the lower part of the stator and brought out through the sealing insulating plug. The internal cavity of the generator is filled with lubricating fluid through the channel for refueling.

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 the drawing.

The downhole tool power generator is installed in a protective housing 1, for example, a drill pipe string or in a casing string, and contains at least one device for mounting the generator. For example, the drawing shows a generator mounted inside the protective housing 1 on two supports - the upper 2 and lower 3. In the upper support 2 holes are made for the passage of drilling mud "A", in which bushings are made of superhard material 4, in the lower support 3 are made hole "B" for the exit of drilling fluid. The main feature of the generator is that a biotic turbine is used, i.e. turbine with opposite rotating stages of the turbine: the main stage of the turbine 5 and the additional stage of the turbine 6. The main stage of the turbine 5 is mounted on the turbine body 7, which is connected to the main rotor 8. The main rotor 8 is mounted on the bearing 9 on the one hand and on the other hand on the upper part of the stator 10, which, in turn, is installed in the upper support 2.

An additional stage of the turbine 6 is installed on the additional rotor 11, which, in turn, is mounted on two bearings 12 and 13 using the shaft of the additional rotor 14, which is expediently made of two parts - the upper part 15 and the lower part 16 and connected with a spline coupling 17. The additional rotor 11 is connected to the shaft of the additional rotor 14 by means of a key 18. On the shaft of the additional rotor 14, more precisely, on its upper part 15, an excitation winding 19 is installed, permanent magnets 20 are mounted concentrically inside the main rotor 20. B the lower part of the generator on the lower part of the shaft of the additional turbine 14 has a primary winding of the contactless energy transfer device 21, and concentrically inside the lower part of the stator 22, a secondary winding of the contactless energy transfer device 23 is installed, which is not part of the device. The field winding 19 and the primary winding of the contactless energy transfer device are connected by intermediate wires 24, which extend inside the shaft of the additional rotor 14. The cavity “B” inside the generator is filled with lubricating fluid. Refueling is carried out through the channel "G", which is closed by a screw 25. The sealing of the rotating parts of the rotors relative to each other and relative to the stator is carried out by mechanical seals 26, 27 and 28. From the secondary winding of the wireless communication device 23, energy is transmitted through wires 29 through a sealing insulating plug 30 downhole equipment 31.

When the generator is operating, the drilling fluid passes through the steps of the biotative turbine 5 and 6. The steps of the birobative turbine 5 and 6 rotate in different directions with approximately the same speed, for example 3000 rpm. If we take into account that in a classical turbine the rotor rotates relative to the stator with an angular speed of 3000 rpm, then the relative rotation speed of the rotors 8 and 11 will be twice as high, namely 6000 rpm. In this case, the first downstream stage of the birobotational turbine 5 will act as a nozzle apparatus for the second downstream stage of the turbine 6. This will make it possible to abandon the use of guide vanes and increase the efficiency and power of the turbine. Also, it became possible to significantly reduce the diametrical dimensions of the generator or increase its power by 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 a contactless transmission of electrical energy can slightly increase the axial dimensions of the generator, however, this is permissible, since the generator together with the downhole tool can be installed in a drill or casing, assembled from pipes up to 10 ... 12 m long. Layout diameter: the generator-downhole tool is strictly limited by the diameter of the drill string. Electricity is transmitted through the intermediate wires 24 from the excitation winding 19 to the primary winding of the contactless electric power transmission device 21. Since the primary winding 21 of this device rotates in the stationary secondary winding of the contactless electric power transmission device 23 installed outside the generator. Electric energy is transmitted through wires 29 to downhole equipment 31.

The sealing of the rotors relative to each other and relative to the stator is carried out by mechanical seals.

The application of the invention allowed:

1. Significantly reduce the diametrical dimensions and weight of the generator.

2. Increase the power and voltage at the electrical terminals of the generator.

3. Significantly increase the life of the supports due to the use of multi-bearing schemes, reducing the diameter of the rotors and the use of two rotors instead of one.

4. To reduce the imbalance of the generator rotors by reducing their diameter by 1.5 ... 2.0 times.

5. To increase the reliability of sealing the cavity of the generator through the use of mechanical seals.

6. Simplify the design of the generator by eliminating the use of guide vanes of the turbine and the maximum simplification of the design of the seal.

7. To simplify the assembly and disassembly of the generator due to the ego implementation of a modular design.

8. Simplify and facilitate electrical wiring, as intermediate wires connect windings rotating at the same speeds and pass inside the shaft of the additional rotor, which eliminates their damage during operation.

9. Improve the maintainability of the generator.

Claims (2)

1. The power generator of the downhole equipment, comprising a protective housing and at least one attachment point, an electrical connector mounted on the shaft of the rotor with a turbine, a stator, permanent magnets and an excitation winding, characterized in that an additional rotor is installed on the shaft on the supports and a device for contactless transmission of electricity, made in the form of primary and secondary windings, one of which is installed on the turbine housing, which is connected to the main rotor, and the second on the additional rotor, with the stator and VA made of two parts - the upper and lower parts, the upper and lower parts of the shaft are interconnected, the field winding is mounted on the shaft in its upper part, permanent magnets are mounted concentrically with it inside the main rotor, the primary winding of the device for non-contact power transmission is installed on the lower part of the shaft and, concentrically, a secondary winding is installed inside the lower part of the stator, while the primary winding and the field winding are electrically connected for contactless transmission of electricity, and the secondary The winding is connected to the electrical connector by electric wires passing inside the hole made in the lower part of the stator and brought out through the sealing insulating plug. 2. The generator according to claim 1, characterized in that the internal cavity of the generator is filled with lubricating fluid through the channel for refueling.