RU2845975C2 - Hydraulic electric machine of underwater design - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: invention relates to the field of hydraulic electric machines operating under water. Hydraulic electric machine of underwater design contains stator with winding placed on fixed hollow bearing shaft 1, outer rotor 5 including a sealed shell rotating around the stator, working element 3 fixed outside the sealed shell and located under water, a protective sealing medium. Machine is equipped with tight protective cover with neck 8 forming together with external rotor 5 common tight external rotor cover 2 rotating around stator, elongated along axis of shaft 1 and filled with protective sealing medium. Shaft 1 is inclined in vertical plane along water flow. Machine is made with possibility of operation in generator or motor modes. Neck 8 is located above or below water surface.

EFFECT: invention is aimed at providing reliable waterproofing, providing reliable cooling, increasing structural strength, improving weight and energy indicators, increasing the duration of fault-free operation and overhaul life.

5 cl, 7 dwg

Description

Field of technology

The invention relates to the field of hydraulic electric machines (hereinafter referred to as hydraulic EM) located underwater and operating in generator or motor modes, with a working element in the form of a propeller turbine or a propeller.

State of the art

There are various technical solutions aimed at ensuring the operation of electrical machines under water. One of the most important aspects is ensuring reliable waterproofing of moving units, primarily sealing of rotating shafts.

The prior art discloses sealing devices for the propeller drive shaft of a vessel that ensure hull sealing. They include sealing rings, packing, and other elements. "Sterntube Seal Line for Propeller Vessels", Admiral S.O. Makarov State University of Maritime and River Fleet, 2021 - describes in detail the designs of stern tube seals, including lip, gland, and end types. Makarov G.V. "Sealing Devices", 2nd ed., 1973 - discusses various seal designs to prevent liquid and gas leaks, including marine solutions. The use of sealing devices allows you to protect the bilge space of a vessel from water, but their use increases friction, which reduces the torque on the engine shaft and increases wear. This leads to an increase in the cost of maintenance and repair. At the same time, the efficiency of such seals does not completely eliminate water seepage, so special pumps are used to pump water out of the sealed volumes.

Known is the patent for invention KR 1020090008757 A (29.10.2009) "Generator with a vertical impeller axis", in which one of the tasks to be solved is to protect the bearings and generator of a vertically located shaft of a hydraulic turbine from water. To do this, the hollow chamber is first filled with compressed air or an inert gas. The rotating shaft of the impeller blade with a vertical axis comes out of the lower entrance of the compressed air seal chamber, and the bearing and generator, connected to the rotating shaft, are located inside this chamber. The design of the turbine is complex, since in order to prevent water from entering the bearing assembly and generator during installation, a detachable shaft is used, which is successively assembled during underwater work, and the turbine axis can only have a vertical position.

Known is the patent for invention RU 2557836 C1 (26.08.2015) "Run-of-river hydroelectric power station of the Russian engineer Sergei Timofeevich Zheleznyakov", installed on a foundation in an artificial channel. It can contain several rigid elliptical casings with turbine modules. To increase the torque, it is proposed to increase the diameter of the propeller turbine, and to use rivers with a relatively shallow flow, the plane of rotation of the turbine blades is deflected at an angle to the flow axis. This allows the hydroelectric power station casing to be made with an elliptical cross-section, which reduces the overall height and allows the use of shallow river flows. This solution is focused on stationary energy generation in certain conditions of the channel flow and does not affect universal solutions for sealing and operation in the motor mode, which are relevant for mobile underwater vehicles.

From the patent for invention RU 2297358 C2 (20.04.2007) "Ice-class vessel... propulsion unit and main propulsion system of an ice-class vessel". The vessel contains a rotating main propulsion system with a propulsor, which can be made in the form of a propeller. The main propulsion system can be equipped with an electric drive in the form of an electric motor. When moving the vessel, the stern end is predominantly forward, and the thrust vector of the propulsor can be directed at an angle to the plane of the waterline by tilting the propeller axis in the vertical plane.

From the invention patent RU 2097266 C1 (27.11.1996) "Main propulsion plant of a ship" a plant is known that can be installed obliquely, so that the angle between the axis of rotation and the propeller shaft is approximately 80°. The propeller is located close to the inclined aft part of the bottom of the ship's hull, which is flown around by water. The inclined position of the propulsion plant ensures the operation of the propeller in the main direction of the water flowing past it. Inside the propulsion plant, the pressure is maintained above the maximum water pressure, since water does not leak in and cannot cause damage to the equipment. The pressure is maintained using a compressor device and is controlled automatically. This solution uses the principle of creating excess pressure for sealing, but requires additional compressor systems.

The design of the electric motor CN 111152907 A (04/15/2020) operating underwater with an external rotor is known, which can be considered an analogue. The main disadvantage of such designs using traditional sealing methods is the presence of contact sealing rings to protect the internal cavity from water, subject to wear.

Also known is patent FR 638393 A (23.05.1928, B63H 23/34), which describes a propulsion system with an inclined shaft extending from an internal combustion engine located on a boat to an underwater propeller. The shaft is partially flexible and has a bend. The design does not contain an electric motor, is not intended to operate in generator mode and does not provide for means of sealing the underwater drive.

The closest analogue (prototype) in terms of the set of essential features is the hydraulic electric machine disclosed in patent GB 2 050 525 A.

The specified prototype contains:

a stator with a winding placed on a fixed hollow supporting shaft;

an outer rotor comprising a sealed shell rotating around the stator;

a working element fixed outside the sealed shell and located in water;

as well as a protective sealing medium filling the hermetic shell.

The disadvantages of this prototype are:

Sealing of the rotating rotor shell relative to the stationary shaft is carried out using mechanical contact seals, which are subject to wear, require maintenance, create friction losses and do not guarantee the complete absence of leaks over a long service life, reducing reliability.

The prototype sealing principle, based on contact seals, does not allow for the flexible and simple implementation of a contactless waterproofing method based on the use of a special structural element such as a neck and a specific inclined position of the machine relative to the water surface.

The device in the prototype is described primarily as a generator, which limits its versatility, while efficient operation in motor mode is not disclosed.

Disclosure of the essence of the invention

The task, which the claimed invention is aimed at solving, is the creation of a design for a hydraulic electric machine of underwater design, capable of operating in both generator and motor modes.

The technical result of using this invention consists in ensuring reliable waterproofing of hydraulic EM, ensuring reliable cooling, increasing the strength of the structure, improving weight and energy indicators, reducing the cost of production and increasing the terms of trouble-free operation of hydraulic EM and inter-repair maintenance.

The stated problem is solved and the specified technical results are achieved due to the fact that a hydraulic electric machine of underwater design, containing a stator with a winding, placed on a fixed hollow supporting shaft, an external rotor, including a hermetic shell rotating around the stator, a working element, fixed outside the hermetic shell and located in the water, as well as a protective sealing medium filling the hermetic shell, according to the invention, is provided with a hermetic protective shell with a neck, forming with the external rotor a single hermetic external rotor shell, rotating around the stator, extended along the axis of the fixed hollow supporting shaft, wherein the fixed hollow shaft is located with an inclination in a vertical plane along the water flow, the machine is designed with the possibility of operating in generator or motor modes, and the neck is located above or below the surface of the water.

In addition, when the neck is located above the water surface, the shaft is fixed above the water surface to a fixed base when operating in the generation mode or to a movable base when operating in the engine mode.

In addition, when the neck is located under the surface of the water, the shaft is secured under the surface of the water to a fixed base when operating in the generation mode or to a movable base when operating in the motor mode.

In addition, the single sealed outer rotor shell is made detachable.

In addition, it is equipped with an additional fixed stationary shaft, located coaxially with the fixed hollow supporting shaft, and an additional protective shell, combined with the sealed shell.

Brief description of the drawings

Fig. 1 - general view of a hydraulic electric machine with an external rotor.

Fig. 2 is a longitudinal section of the hydraulic electric machine shown in Fig. 1.

Fig. 3 - design diagram of the basic version of a hydraulic electric machine with an external rotor.

Fig. 4 - design diagram of a reinforced version of a hydraulic electric machine with an external rotor.

Fig. 5 - installation option of the basic version of a hydraulic electric machine with a neck (pos. 8) of a rotor shell located above the water surface.

Fig. 6 - installation option of the basic version of a hydraulic electric machine with a neck (pos. 8) of a rotor shell located under the surface of the water.

Fig. 7 - a variant of installation of a reinforced hydraulic electric machine with a neck (pos. 8) located above the water surface.

Implementation of the invention

The hydraulic EM consists of a stator 4 consisting of a stator winding and a magnetic circuit, an external rotor 5 consisting of a sealed shell containing a ferromagnetic circuit on the internal surface of which permanent magnets or a magnetic circuit with an excitation winding are located, a fixed hollow supporting shaft 1, a sealed protective shell 2, a working element 3. The stator 4 is located on the fixed shaft 1. The external rotor 5 is located around the stator 4. The protective shell 2 has a neck 8 and forms with the rotor 5 a single sealed external rotor shell, which can be detachable or non-detachable (Figs. 1-3). The working element 3 is located on the external surface of the rotor shell. The rotor shell and the working element 3 can rotate relative to the stator 4 and the fixed shaft 1 using bearings (not shown). The internal volume of the rotor shell can be filled with a gaseous or oil sealing medium. The hydraulic EM is fixed above the water surface relative to a fixed or moving base using a mount.

The working element 3 is located under water. In the working position, the hydraulic EM is inclined relative to the horizontal to hold the sealing medium inside the rotor shell.

To increase the strength of the hydraulic EM structure and the reliability of its fixation in the working position, the number of supports can be increased. In this case, the hydraulic EM includes an additional fixed shaft 7, a small hermetic shell 6 with a neck 8. The additional stationary shaft 7 is coaxial with the fixed hollow shaft 1. The small hermetic shell 6 is structurally connected to the main rotor shell and rotates together with it. (Fig. 4) The small hermetic shell is filled with a sealing medium, and a bearing assembly is located inside it. The working element 3 is located under water. In the working position, the hydraulic EM is fixed using the fasteners of the additional fixed shaft 7 and the fixed hollow shaft 1 and is tilted relative to the horizontal.

To increase heat transfer from the hydraulic EM units to the washing water environment and the possibility of using synchronous machines of traditional design with an internal shaft arrangement, the rotor can be located inside the stator 4. In this case, the external stator 4 is fixed on a fixed hollow supporting shaft 1. The rotor 5 is located inside the stator and is connected to the end inner surface of the hermetic protective rotor shell. The rotor 5, shell 2 and working element 3 can rotate relative to the stator 4.

During operation, the hydraulic EM is immersed in water. The supporting hollow shaft 1 is fixed above the water surface using a fastener in such a way that the neck 8 of the rotor shell remains above the surface at a height that prevents water from entering the hollow shell 2. In this case, the axis of the hydraulic EM is inclined relative to the horizontal (Fig. 5).

When operating in the generator mode, the hydraulic EM is attached to a fixed base. The working element 3 in the form of a propeller turbine converts the energy of the water flow into the torque of the rotor shell rotating around the stator 4. Electric current is generated, which is transmitted via a cable (not shown) laid in the hollow supporting shaft 1. When operating in the engine mode, the hydraulic EM is attached to a movable base, for example, to a vessel. Voltage is supplied to the hydraulic EM via the cable, the rotor 5 begins to rotate together with the rotor shell. The working element 3 in the form of a propeller converts the torque of the hydraulic EM into a force applied to the shaft mount.

The water flow can be smoothly flowing along a channel with a slight slope. In this case, the hydraulic EM can operate both in the generation mode and in the engine mode. The water flow can also be falling from above, for example, from a dam. In this case, the hydraulic EM can operate, as a rule, in the generation mode.

In another application variant, the supporting shaft 1 is fixed under the water surface using a fastening so that the neck 8 of the shell 2 is at the bottom point of the rotor shell. (Fig. 6) Water can rise inside the hollow rotor shell to the level where the pressure of the sealing medium inside the hollow shell 2 is greater than or equal to the pressure of the outer water column. In this case, the electrical components and bearing assemblies are in the sealing medium above the water level. The axis of the hydraulic EM is inclined relative to the horizontal. The hydraulic EM can operate in the generator mode or in the engine mode.

The flow of water can be smoothly flowing along a channel with a slight slope or falling from above, for example, from a dam.

The machine can be made in a reinforced design. In this case, in addition to the main shaft 1, it is equipped with an additional fixed stationary shaft 7, located coaxially with the main one, and an additional protective shell 6, combined with the main rotor shell (Fig. 4, 7).

Claims (5)

1. A hydraulic electric machine of underwater design, comprising a stator with a winding, placed on a fixed hollow supporting shaft, an outer rotor, including a sealed shell rotating around the stator, a working element, secured outside the sealed shell and located under water, a protective sealing medium, characterized in that it is equipped with a sealed protective shell with a neck, forming with the outer rotor a single sealed outer rotor shell, rotating around the stator, extended along the axis of the fixed hollow supporting shaft and filled with a protective sealing medium, and the fixed hollow shaft is located with an inclination in a vertical plane along the water flow, wherein the machine is designed with the possibility of operating in generator or motor modes, and the neck is located above or below the surface of the water. 2. The machine according to item 1, characterized in that when the neck is located above the surface of the water, the shaft is secured above the surface of the water to a fixed base when operating in generation mode or to a movable base when operating in engine mode. 3. The machine according to item 1, characterized in that when the neck is located under the surface of the water, the shaft is secured under the surface of the water to a fixed base when operating in generation mode or to a movable base when operating in engine mode. 4. A machine according to any of paragraphs 1-3, characterized in that the single sealed outer rotor shell is made detachable. 5. A machine according to any one of paragraphs 1-4, characterized in that it is equipped with an additional fixed stationary shaft located coaxially with the fixed hollow supporting shaft and an additional protective shell combined with the hermetic shell.