RU2465708C1 - Submersible valve-inductor electric motor of open design - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: electric motor comprises a body (1), where a stator yoke (2) is placed with explicit-pole teeth (3), excitation coils (4) from a winding wire with polyimide-fluoroplastic insulation. On a shaft (6) there is a rotor (7) mounted with similar teeth (8) without a winding by number by two teeth less than on the stator. Between the teeth (3) of the stator and teeth (8) of the rotor there is a non-magnet working gap (10), along which cooling sea water passes. To prevent contact corrosion of electric steels of packages of the stator, rotor, body and shaft, discs (11) from magnesium alloy are pressed onto free ends of the rotor shaft, and between the stator teeth there are tyre treads (5) pressed from the same alloy. Discs (11) and tyre treads (5) have a tight electric contract with packages of the rotor (7) and the stator (2).

EFFECT: higher reliability, operability, durability and energy characteristics of valve-inductor electric motors of open design by higher efficiency of electrochemical protection of inner active parts against contact corrosion with their submersion into sea aggressive water - electrolyte.

3 dwg

Description

The invention relates to the field of marine electrical engineering, in particular to submersible electric machines that are used to drive propellers, active rudders of thrusters, mooring and anchor mechanisms, various pumps, water cannons, etc. deep-sea underwater inhabited and uninhabited vehicles, as well as pump and drilling machine drives in the oil and gas industry.

Scientific and technological progress and prospects for the development of intensive development of the extraction of mineral resources from the bottom of the World Ocean and on the mainland, for example, the development of new oil and gas deposits in the Siberian energy region of Tyumen, Orenburg, as well as the development of large mineral oil and gas resources of the Arctic continental shelf, are required quite a lot of technical means and working mechanisms that should be driven by highly reliable submersible electric motors (PED), having high energy These features and a wide range of speed control. In addition, for deep-sea underwater inhabited and uninhabited vehicles (GPU) of the Navy at great depths and for exploring the depths of the oceans, submersible electric motors with reduced weight and size characteristics are required.

Until now, submersible, sealed, oil-filled PEMs with a rather complex multi-stage hydraulic protection and multi-stage mechanical seals installed on the drive side have been used to drive various GPU outboard mechanisms (propellers, thrusters, pumps, etc.), as well as to drive pumps and oil well drilling mechanisms. shaft. When the seals are opened and outboard water enters the engine cavity, it fails due to electrochemical corrosion of the active parts and a decrease in the insulation resistance of the stator winding, i.e. sealed oil-filled PEDs have reduced reliability and performance. The PED is cooled by outboard ambient water through the housing.

Currently, work is underway to introduce environmentally friendly open-type SEMs, mainly of the asynchronous type, to drive GPU outboard mechanisms for the Navy and oil and gas rigs with cooling of the inside parts with outboard aggressive water. These machines have high reliability, unlimited immersion depth, work with any roll and trim, have a long resource and service life. (see. V. Vetokhin. New AMV-5 submersible electric motor. Shipbuilding. 1997, No. 4).

Over the past 20 years, new designs of valve induction motors (VID) have been used in the air industry. VID is a relatively new type of electromechanical energy converter that combines the properties of both an electric machine and an integrated system of controlled electric drive. VID is an induction machine in which energy is converted by changing the inductances of the windings located on the pronounced teeth of the stator, due to the movement of the rotor magnetic circuit of the rotor relative to them without a winding. The VID is powered by a valve converter (switch), which alternately switches the stator windings of the motor in strict accordance with the signals from the rotor position sensor. A microprocessor is used to control the semiconductor converter. With sequential, periodic switching of the stator phases, the rotor rotates at an angular speed proportional to the switching frequency.

ADVANTAGES OF VIEW:

1) reliability and simplicity of design and manufacturing technology;

2) the ability to receive both ultra-high and ultra-low shaft speeds;

3) lack of sliding electrical contact;

4) electromagnetic reduction of the rotation of the VID and the flexibility of the control system;

5) the VID rotor has a small moment of inertia, which positively affects the dynamics of its work;

6) VID is able to work in heavy overload conditions and in a wide range of loads;

7) VID has high energy characteristics and efficiency.

Valve-inductor electric drives have not yet found mass application. Partially used in some types of electric drives for general industrial use in the air, for example, electric vehicles, machine tools, household appliances, etc. (see DVI 500/3000-UZ produced by RUSELCOM). The issue of using VID as drives operating in seawater and aggressive environments has not been raised to date, the authors first began to work on this problem.

A known open-type electric machine is the Vetokhin Electric Machine EMV, (see patent No. 2072609, BI No. 3, 01/27/97), which contains a stator, a rotor with a shaft mounted in bearings, a housing filled with a liquid cooler, and bearing shields with holes. Sea water was used as a cooler, and the holes in the bearing shields for water inlet and outlet are located in two groups. This machine provides reliable operation as the drive of any underwater mechanism located at an unlimited depth of immersion in sea water and the openings in the shield provide reliable cooling of all active parts of EME. However, this machine does not have electrochemical tread protection, so its active parts inside the machine will undergo contact corrosion in sea water, and its life will be limited.

Of the well-known electric machines, the closest to the claimed one, chosen as a prototype, is the Vetokhin Electric Machine EMV (see patent No. 1813228, Bull. No. 16, 04/30/93), which contains a stator with a three-phase long winding and a rotor with a copper short-circuited winding . Cooling is carried out by the surrounding fluid entering and leaving through openings in the bearing shields. To protect against contact corrosion of the internal active parts of the machine on the rotor shaft and in the stator housing, protector bushings made of aluminum alloy are pressed from both ends, the length of which in the axial direction is from 0.05 to 0.1 of the length of the rotor core package. However, the use of tread bushings and machine rings do not allow their use in valve-induction electric motors, in which the stator and rotor cores have a clearly polar design.

The aim of the invention is to significantly increase the reliability, survivability, durability and energy characteristics of the developed open-type submersible valve-induction electric motor when working in sea water at any depth of immersion by eliminating contact corrosion of the stator and rotor electrical steel using tread tires of the stator located between the teeth of the package stator, and tread disks of the rotor with teeth pressed onto the free ends of the shaft close to the rotor package. In addition, the creation of a smooth cylindrical outer surface of the rotor with pressed monolithic non-magnetic wedges between adjacent teeth of the rotor will significantly improve the vibro-acoustic characteristics of the machine (CVC).

This goal is achieved by the fact that in the well-known submersible valve-induction electric motor of open design, containing a stator with a yoke and explicit pole teeth with excitation coils on them, a rotor with explicit pole teeth without winding, a shaft mounted in bearings, and bearing shields with holes for entry and out of the surrounding sea water, the stator has tread protection in the form of arc tire protectors made of aluminum-magnesium-zinc alloy with a thickness of 8-10 mm and a length equal to the length of the stator packet inserted between adjacent and teeth close to the inner surfaces of the yoke and the side surfaces of the teeth, and the rotor has a tread protection of the same alloy in the form of disks with teeth of the same thickness and beads 8-10 mm thick, pressed onto the free ends of the shaft close to the end surfaces of the rotor package with teeth and completely covering them with a tight electrical contact between the disk, the rotor package and the shaft, while in the space between adjacent teeth along the axial guides under the ends of the teeth high-strength monolithic non-magnetic wedges are placed made of fiberglass or similar material with a length equal to the sum of the length of the rotor package and two thicknesses of the tread discs, and these monolithic wedges together with the teeth represent a single cylindrical design of the rotor package with a smooth outer surface.

The invention is illustrated by drawings, in which:

figure 1 shows a cross section of a 3-phase submersible valve-inductor electric motor open design;

figure 2 shows the rotor VIED (top view);

figure 3 shows the tread disc of the rotor with teeth.

According to the invention, an open-type submersible induction motor (Fig. 1) comprises a housing 1 with a diameter Dcorp, in which a yoke 2 stator with explicit pole teeth 3 with a non-magnetic gap D1 and excitation coils 4 are placed on them from a winding wire with polymide-fluoroplastic insulation, for example, PPI brands. The stator has tread protection against contact corrosion of the yoke 2 with a diameter of Da and the stator teeth 3 in the form of arc tread tires 5, pressed into grooves close to the inner surfaces of the yoke 2 and the side surfaces of the teeth 3 with a length equal to the length of the stator packet 11 and a thickness of at least 8- 10 mm, for example, from a magnesium alloy brand ML4 (Figure 1). On the shaft 6 there is a rotor package 7 having explicitly polarized teeth 8 with a diameter along the non-magnetic gap D2, and high-strength monolithic cylindrical wedges 9 (Figure 1, Figure 2) made of fiberglass or similar material are pressed into the space between adjacent teeth 8 of the rotor the purpose of giving the rotor a smooth cylindrical shape. The length of the wedges should be equal to the sum of the length of the package of the rotor 11 and the doubled thickness of the tread discs h. Between the teeth of the packages 8 of the rotor and the teeth 3 of the packages of the stator there is a non-magnetic working gap 10 (δ), through which there passes cooling outboard aggressive water with the properties of an electrolyte. The rotor has tread protection against contact corrosion of the yoke 7 and teeth 8 of the rotor package in the form of disks 11 with teeth with a thickness h of at least 8-10 mm of the same magnesium alloy as on the stator, covering the completely end surfaces of the rotor package, with tight electrical contact with the package rotor and shaft and having a thickening of 11 with a diameter D in the form of a collar 12 (Figure 3) with a thickness equal to the thickness of the disk h, which will provide mechanical strength of the treads and convenience when pressing the disks onto the free ends of the shaft 6 with a diameter of dval.

The work of a submersible valve-induction electric motor of an open design is as follows. When the rotor rotates in aggressive aggressive seawater (electrolyte), the rotor and stator are in a moving electrolyte environment. With the full contact of all internal active parts of the machine with the electrolyte, electrochemical corrosion occurs on all active metal surfaces in contact with the electrolyte, i.e. on the surfaces of the teeth 8 of the package 7 of the rotor, on the surfaces of the teeth 3 of the package 2 of the stator in the non-magnetic working gap, on the yoke 2 of the stator, on the yoke 7 of the rotor, on the surfaces of the tread disks 7 of the rotor and the tire-tread 5 of the stator. Due to the fact that the electrode potential of the rotor disks 11 and the tire treads 5 of the stator made of magnesium alloy of the ML4 grade is much lower than the electrode potential of the electrical steel of the stator package 2, the rotor package 11 and the shaft 6, electrochemical corrosion of the tread disks occurs 11 rotors and tread tires 5 of the stator with leaching of corrosion products by moving electrolyte. Physically, this means that when the machine is immersed in sea water, the electrolyte, at the ends of the teeth, 3 in the stator bore packages, the galvanic current closes in a circuit: the anode current leaves the tread 5, passes through the electrolyte and enters the teeth 3 of the stator, the teeth of the stator 3 are the cathodes (input of the anode current), and the bus treads 5 are the anodes (output of the anode current); in the rotor, the galvanic current closes in a circuit: the anode current leaves the tread disks with teeth 11, passes through the electrolyte and enters the teeth of the 8 rotor, the teeth of the 8 rotor are cathodes (anode current input), and the tread disks 11 are anodes (anode current output) . It is known that the cathodes will retain their original state, and the anodes will corrode, i.e. dissolve in electrolyte. In this case, the packages of the stator 2, rotor 7, housing 1 and shaft 6 will be in the initial state, and the protectors 5 and 11 will corrode and decrease in size. Therefore, the tread material will be consumed, and the remaining metal parts of the machine will be in their original state for the estimated, planned life without increasing the non-magnetic working gap and the associated drop in the energy characteristics of the machine, which will be constant throughout its life. The thickness of the disks 11 of the rotor and tread tires 5 of the stator made of aluminum-magnesium alloy should be within (5-8) mm at a corrosion rate of treads of 0.5 mm / year based on the life expectancy for 10-15 years.

The claimed technical solution will significantly improve the reliability, survivability, durability while maintaining the energy characteristics of the developed open-type submersible valve-induction electric motor when operating in sea water at any depth of immersion by eliminating contact corrosion of the stator and rotor electrical steel in the non-magnetic gap using the stator tread tires placed between the teeth of the stator package and the tread disks of the rotor with teeth pressed onto loose gical shaft adjacent to the rotor pack. In addition, the creation of a smooth cylindrical outer surface of the rotor with pressed monolithic non-magnetic wedges between adjacent teeth of the rotor will significantly improve the vibroacoustic characteristics (CVC) of the machine.

Claims (1)

An open-type submersible valve-induction electric motor containing a stator with a yoke and explicit pole teeth with excitation coils on them, a rotor with explicit pole teeth without winding, a shaft installed in the bearings, and bearing shields with holes for the input and output of surrounding sea water, characterized in that the stator has tread protection in the form of arc tire protectors made of aluminum-magnesium-zinc alloy with a thickness of 8-10 mm and a length equal to the length of the stator packet inserted between adjacent teeth closely to the inside the lower surfaces of the yoke and the lateral surfaces of the teeth, and the rotor has a tread protection of the same alloy in the form of disks with teeth of the same thickness and shoulders 8-10 mm thick, pressed onto the free ends of the shaft close to the end surfaces of the rotor package with teeth and completely covering them with tight electrical contact between the disk, the rotor package and the shaft, while in the space between adjacent teeth along the axial guides under the ends of the teeth high-strength monolithic non-magnetic wedges made of fiberglass or tax material with a length equal to the sum of the length of the rotor package and two thicknesses of the tread discs, and these monolithic wedges together with the teeth represent a single cylindrical design of the rotor package with a smooth outer surface.

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