RU2539572C2 - Inductor machine with axial flux for severe operating conditions - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: invention is related to the sphere of electric engineering, and namely to inductor machines with contactless switching performed by semiconductor devices, and may be used for electric drives of different purpose as well as in electricity generation systems at high demands to reliability. The inductor machine with axial flux comprises a cylindrical body (1), the stator (3) with winding, the rotor without winding with an external shaft (4) having n magnetic teeth (5) and a disc plate of non-magnetic material (6).

EFFECT: improved reliability of functioning in unfavourable operating conditions; the machine design envisages effective cooling of the stator and especially rotor, thus providing in result high specific load capacity of the whole inductor machine.

2 cl, 4 dwg

Description

The invention relates to the field of electrical engineering, namely to induction machines with non-contact switching, carried out using semiconductor devices, and can be used for electric drives for various purposes, as well as in power generation systems with increased reliability requirements. The primary field of application is the electric propulsion systems of underwater, deep-sea inhabited and uninhabited vehicles, ships of the sea and river fleet, as well as electric pumps, compressors operating in harsh operating conditions.

End-face electric machines are known (RF Patent No. 2448404 for the invention of ELECTRICAL ELECTRIC MACHINE dated 02.24.2011, IPC H02K 16/02 (2006.01), H02K 1/06 (2006.01), Patentee: Evgeny Konstantinovich Puchkin and RU Patent No. 2313888 for the invention of ELECTRICAL ELECTRIC MACHINE dated 06/15/2006, IPC H02K 21/24 (2006.01), H02K 21/12 (2006.01), H02K 16/02 (2006.01), Patent holder: State Educational Institution of Higher Professional Education Krasnoyarsk State Technical University (KSTU ) (RU)).

The main common drawback of these machines is - in connection with the use of ferrite cores with short-circuited windings in the design of the rotors - a certain limitation on the load capacity due to the lack of the possibility of efficient cooling of both the rotor and the motor as a whole.

An electric motor is also known (International Patent Application No. WO / 2010/084530, ELECTRIC MOTOR, 05/07/2009, IPC H02K 16/02 (2006.01), H02K 21/24 (2006.01), Applicants: KASAI, Toshiyuki [JP / JP], OKAMOTO , Tetsuo [JP / JP]), comprising a housing with a stator in the middle of the motor, which is composed of two windings located between them with a flat ring with 4 pairs of permanent magnets; the motor shaft with two bearings, with two flat disk rotors fixed on it (from the left and right outer end faces of the motor stator), on the surface of which there are 2 pairs of permanent magnets having the shape of a ring sector (1/4 ring), limited radii, as well as the outer and inner (from the motor shaft side) circumference of the rotor disk, as well as two cam-type electrical contact switches mounted on one of the motor shaft outputs.

The disadvantages of this electric motor are:

- a relatively complex stator design, which occupies a significant part of the engine volume;

- use when switching the stator windings (to create a rotating magnetic field) of an electrical contact switch (relative to an unreliable electric motor assembly), requiring regular maintenance.

The electric drive is known (RF Patent No. 2219642 for the invention of an ELECTRIC DRIVE (OPTIONS) dated 12/12/1999, MPK7 Н02К 21/12, Patentee: EDVENCED ROTARY SYSTEMS, LLS. (US)), containing a rotor and a stator, while the rotor is made in the form of two washers with poles distributed around the circumference and placed between the washers of the cylindrical magnet, magnetized in the axial direction so that the poles of each of the washers are of the same name, and opposite to the poles of the other washer, the stator is made in the form of coils distributed around the circumference, exl sistent in that the rotor poles are formed by teeth made on the inner circumference of both washers facing the axis of the device and disposed in planes perpendicular to the tool axis and the poles of the stator coils are arranged to mechanical interaction with the rotor poles.

Also known is a synchronous jet electric motor (RF Patent No. 2057389 for the invention SYNCHRONOUS REACTIVE ELECTRIC MOTOR from 02.16.1994, IPC6 Н02К 19/06, Patentee: Novosibirsk State Technical University (RU)), containing a stator with an m-phase winding and an explicit pole rotor, whose magnetic circuit is made of ferromagnetic packages located along the active surface of the engine, consisting of individual elements, characterized in that the ferromagnetic packages are made U-shaped from elements, the side surfaces of which x are parallel to the axis of rotation of the rotor, the radially oriented sections of the packages are located within the active volume of the rotor and have a variable height that varies linearly from zero on the outer radius to the maximum value on the inner radius of the core of the machine, the tangentially oriented sections of the packets have a constant height and are located in area bounded by the internal radius of the active engine volume.

When using these technical solutions (Patents of the Russian Federation No. 2219642 and 2057389) in harsh operating conditions, for example, when operating as part of an electric pump for pumping aggressive liquids or as a propeller drive for the electric propulsion system of an underwater inhabited and uninhabited apparatus, it is necessary to ensure reliable sealing of the internal volume of the electric motor from the environment, which is a rather complicated technical problem, including requiring regular maintenance of the seal assembly one shaft during operation.

In addition, since existing seal designs of the output shaft of the electric motor are often (with a high pressure value) unable to provide the necessary sealing, the developers of electric systems for deep-sea vehicles are forced to create special oil-filled electric motors with pressure equalization devices or to supplement the main motor with a special electromagnetic coupling to transmit torque execution (see, for example, Certificate for utility model of the Russian Federation No. 36923 "Seals Rowan magnetic coupling "), etc.

The closest in technical essence to the claimed solution is a valve motor generator (RF Patent No. 117167 for a utility model VENTILY MOTOR-GENERATOR WITH VARIABLE MAGNETIC SYSTEM GEOMETRY of September 13, 2011, IPC F02N 11/04 (2006.01), H02K 29/00 (2006.01 ), H02K 1/06 (2006.01), Patent holders: Milov Vladimir Nikolaevich (RU), Milov Evgeny Vladimirovich (RU), Sipin Ivan Alexandrovich (RU), Karpinsky Alexander Ivanovich (RU), Andreyenko Aleksandr Stepanovich (RU), containing engine block , a stator with an anchor winding located on it and a rotor with an external shaft.

The main disadvantage of the prototype is that the design of this valve motor generator with variable geometry of the magnetic system does not ensure its operation in harsh operating conditions.

In accordance with the classification of electric motor operating conditions developed by the All-Union Scientific Research, Design and Technological Institute of Electric Machine Engineering (VNIPTIEM), Vladimir (see Web page: http://leg.co.ua/info/elektricheskie-mashiny /ekspluataciya-elektrodvigateley-v-selskom-hozyaystve-4.html), the operating conditions are divided into light, normal, hard and especially harsh. Light operating conditions mean that one or more factors affecting the reliability of the electric motor deviate from the nominal modes in the direction of facilitating them. Severe conditions are characterized by the presence of one of the factors (for example, such as: humidity, dampness, special dampness, chemically active medium), the value of which is higher than the nominal level. Particularly severe conditions are characterized by the presence of two or more factors exceeding the nominal values, or one of the factors, due to the extremely high deviation of which from the nominal level, the reliability of the electric motor is significantly reduced.

The aim of the invention is the creation of an induction machine with axial magnetic flux, providing increased requirements for reliability in harsh operating conditions.

This goal is achieved by the fact that in the induction machine with an axial magnetic flux containing a cylindrical body, a stator with a winding located on it and a rotor with an external shaft, a multiphase winding is installed in the cylindrical body of the induction machine and made in the design of the end type forming “m” of magnetic poles uniformly distributed over the end surface of the stator; the rotor is a flat disk, and on the end side of the rotor disk facing the “m” magnetic poles of the stator, there are “n” magnetic teeth evenly distributed over the end surface of the rotor; moreover, in the gap between the stationary magnetic poles of the stator and the movable magnetic teeth of the rotor, a disk plate of non-magnetic material is installed that insulates the internal volume of the cylindrical body of the inductor machine with the stator from environmental conditions, in which the windingless rotor with the external shaft of the inductor machine is directly located.

In addition, the interdental zones “n” of the magnetic teeth of the rotor disk are filled with a non-magnetic composition.

As a non-magnetic composition, a non-magnetic material can be used, for example, a polymer mass, which after solidification forms a monolithic structure of the end side (surface) of the rotor disk facing the “m” magnetic poles of the stator.

The invention is illustrated graphic materials.

In FIG. 1 shows a longitudinal section through an axial magnetic flux induction machine.

According to FIG. 1, an axial magnetic flux induction machine includes a cylindrical housing 1, a multiphase stator winding 2 forming “m” of the magnetic poles of the stator 3, a windingless rotor with an external shaft 4 having “n” magnetic teeth 5, and a disk plate of non-magnetic material 6.

In fig. Figure 1 shows the synthesized (simplified) image of a general view of an induction machine with an axial magnetic flux assembly in the 3/4 view (see the Appendix to this description). Moreover, for clarity, the representation of the interaction of the main components of an electric machine (stator and rotor), in Fig. 1, in a simplified representation of a machine structure, the outer rotor shaft and the disk plate of non-magnetic material are not intentionally shown.

In fig. 2 shows a synthesized image of a general view of the stator of an inductor machine (see the Appendix to this description).

In fig. Figure 3 shows a synthesized image of a general view of the rotor of an induction machine with an external shaft (see the Appendix to this description).

In the performance of the inductor machine shown in Fig. 1-3, “m” is 12, and “n” is 8.

The essence of the invention lies in the fact that in the proposed induction machine with axial magnetic flux due to the fact that the stator windings are isolated from the external environment, high reliability is ensured in adverse operating conditions, and the design of the machine provides for effective cooling of the stator and especially the rotor - as a result provides high specific load capacity of the inductor machine as a whole.

The proposed induction machine operates as follows.

Engine mode

Upon entering the multiphase winding 2, forming the "m" of the magnetic poles of the stator 3 (see Fig. 1) of the AC supply voltages, a rotating electromagnetic field is created, which, interacting with the "n" magnetic teeth of the rotor disk, carries them along, creating a rotating the moment on the external shaft of the engine 4 (to simplify the bearing assembly of the external shaft of the engine 4 in Fig. 1 is not shown).

Depending on the values of the supply voltage and the frequency of the current generated by the voltage converter (not shown in Fig. 1), from which the stator winding receives power, the motor accelerates, enters the rated mode of operation, operates with permissible overload, etc.

Moreover, in the proposed induction machine, to ensure an efficient process for controlling the voltage converter, it is supposed to use either a rotor position sensor, including a non-contact type (not shown in Fig. 1) or a control method using counter-EMF signals in current-free sections of the multiphase stator winding 2 (see, for example, technical solutions described in Russian Patents for invention No. 2207700 "Method for controlling a valve electric motor" and No. 2458435 "Drive rotation of a waveguide-slot antenna").

Generator mode

In the generator mode, the external shaft is driven with a rotor 4, which creates a rotating magnetic field, which generates an EMF in the sections of the multiphase winding of the stator 2.

The internal volume of the induction machine in a cylindrical housing 1, in which a stator is mounted, made in the design of the end type with the installed multiphase winding 2, is reliably isolated from the external environment using a disk plate of non-magnetic material 6 (for example, titanium, aluminum alloy, high strength plastic, etc.). In addition, the plate 6 also provides isolation from the external environment of the remaining compartments of the deep-sea apparatus (if it is uninhabited compartments, then with a voltage converter and control system, if inhabited, then it also with people). "M" of the magnetic poles of the stator 3 and "n" of the magnetic teeth of the rotor 5 are formed (wound) from a strip of sheet steel. The multiphase winding of the stator 2 is formed of coils mounted on the "m" magnetic poles of the stator 3.

To improve the reliability of operation and the efficiency of heat energy removal to the machine body, the coils of the multiphase anchor winding of the stator 2 can be impregnated and filled, for example, with a non-magnetic polymer composition, which after hardening provides electrical insulation, mechanical strength and thermal conductivity. And since the windingless rotor with the external shaft 4 is located directly in the external environment (often quite unfavorable, for example, aggressive fluid from the transfer pump, seawater of the propeller, etc.), it is effectively cooled, which in addition to efficient heat removal energy from the multiphase winding of the stator 2 to the machine body - provides a high specific load capacity of the inductor machine as a whole.

The monolithic construction of the end side (surface) of the rotor disk facing the “m” magnetic poles of the stator, formed by filling the interdental zones “n” of the magnetic teeth of the rotor disk with non-magnetic material, ensures a decrease in the value of dynamic losses (hydro- or aerodynamic losses) during rotation of the rotor (in Fig. 1 and Fig. 1, 3 the filling of the interdental zones of the rotor disk is not shown).

Thus, the proposed induction machine provides high reliability of the operation of the device, unit, etc., driven by this machine in motion (in engine mode), or the generation of electricity (in generator mode), and in fairly harsh (adverse) operating conditions.

The technical results obtained in the invention include the following:

- achieving high operational reliability in harsh (adverse) operating conditions of the inductor machine used both as an engine and as a generator (since the stator windings are reliably isolated from the external environment) and, in particular, the absence of the need for regular maintenance of the seal assembly output shaft during operation;

- manufacturability and ease of assembly, as well as high maintainability and, including, low time consumption when replacing failed individual coils in the stator windings (that is, components of the motor-generator that have the lowest reliability);

- in the proposed embodiment of the induction machine, the design of the rotor with magnetic teeth is much simpler than containing the windings, in addition, the inductor machine belongs to non-contact electric machines, that is, it does not contain a collector or slip rings, which complicate operation and reduce reliability;

- the proposed embodiment of the induction machine implements efficient cooling of the stator and especially the rotor, which ensures its high specific load capacity in general;

- the proposed version of the induction machine used as an electric motor can be powered by either a typical two-link converter (DC-DC boost-boost plus an inverter), or directly from an inverter with a PWM controller;

- an embodiment of an induction machine with filling the interdental areas of the rotor with non-magnetic material significantly reduces dynamic losses during rotation of the rotor, which allows to achieve high efficiency in the proposed embodiment of the machine.

Industrial applicability of the invention is determined by the fact that the proposed induction machine can be manufactured in accordance with the above description and drawings (see Fig. 1 and Fig. 1-3) on the basis of known components and technological equipment.

Thus, the proposed induction machine can be used in various fields (energy, mining and oil refining industries, housing and communal services, agriculture, marine and river shipbuilding, etc.) - wherever in harsh operating conditions to electric drives or generators increased demands are placed on reliability, as well as to reduce the complexity of maintenance.

Based on the foregoing and the results of the patent information search, we believe that the proposed induction machine with axial magnetic flux meets the criteria of "Novelty", "Inventive step" and "Industrial applicability" and can be protected by a RF patent for an invention.

Claims (2)

1. Induction machine with axial magnetic flux, containing a cylindrical body, a stator with a winding on it and a windingless rotor with an external shaft,
characterized in that in the stator, mounted in a cylindrical housing of the induction machine and made in the design of the end type, a multiphase winding is installed, forming "m" of magnetic poles evenly distributed over the end surface of the stator; the rotor is a flat disk, and on the end side of the rotor disk facing the “m” magnetic poles of the stator, there are “n” magnetic teeth evenly distributed over the end surface of the rotor;
moreover, in the gap between the stationary magnetic poles of the stator and the movable magnetic teeth of the rotor, a disk plate of non-magnetic material is installed that isolates the internal volume of the cylindrical body of the inductor machine with the stator from environmental conditions, in which the windingless rotor with the external shaft of the inductor machine is directly located. 2. The inductor machine according to claim 1, characterized in that the interdental zones "n" of the magnetic teeth of the rotor disk are filled with a non-magnetic composition.

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