SU1690089A1 - Motor-bearing electric machine - Google Patents

Abstract

The invention relates to electrical engineering. The purpose of the invention is to increase reliability and provide autonomy. The electric machine comprises a stator 1 with a three-phase winding 3, in which a rotor 4 is mounted on a gas-magnetic support. The rotor is equipped with at least two pressure wheels 6 located on both sides of the stator in its bores to form a guide vane 8 for air connected by channels 9 s working gap gas magnetic support. In doing so, to the channels through a controllable valve 17 connected with the electric machine start system; an air receiver is connected. 1 or 3 "(L S o y o o so o

Description

The invention relates to electrical engineering, in particular, to the design of electric motors, which can be used as the electric drive part of high-speed operating elements of various machines, which operate mainly in the absence of a transistor source of compressed gas.

The desire to increase functionality, in particular, speed characteristics, has led to the creation of a new type of electric motor undercarriage, which combines the positive qualities of electric motors and gas-static rotation bearings. There are designs of radial, thrust and angular contact motor bearings.

The closest among the known ones is a radial-type motor-bearing, comprising a stator with a laminated magnet duct, in which grooves a distributed winding is laid. Radial channels are made in the magnetic core, providing a supply of compressed gas into the working gap between the stator and the rotor. The latter is made massive, and on the working surfaces of the rotor and stator there are annular teeth filled with nonmagnetic antifriction material with the formation of a nonmagnetic layer on the stator. Stator: installed in the case, closed with end caps. Compressed gas under pressure is fed through feeders in the magnetic core into the working gap between the rotor and the stator. The rotor floats on the gas lubrication layer. After applying voltage to the winding, the rotor begins to rotate. A stable radial suspension of the rotor is provided by the interaction of the lifting forces of the gas lubrication layer and the electromagnetic forces of attraction of the rotor to the stator. The axial suspension is provided by the electromagnetic non-contact interaction between the rotor and the stator.

The disadvantages of the design are the need to supply compressed gas from an external power source during the entire time of operation of the electric machine, which is often associated with technical difficulties, and sometimes is impossible. In other words, the device cannot work offline. In addition, any failure in the air supply threatens to failure or even damage the gas-magnetic support.

The purpose of the invention is to provide autonomy and increase the reliability of the device.

This goal is achieved by the fact that in an electric machine a motor-bearing containing a stator in the form of a laminated magnetic circuit with a three-phase distributed winding and a rotor mounted in the stator by means of a gas-magnetic support, the working gap of which is connected to a source of compressed air, the source of compressed air is made in the form of two air diffusers installed on both sides of the stator, each of which contains at least one pressure wheel fixed on the shaft and located in the bore of the stator face, and guiding th unit disposed on the end bore, wherein the working air gap on both sides of the support gasmagnetic communicates with pressure

There are 5 cavities of air-blowers, and an air receiver is connected to the supply channels of the support through a controllable valve, which is connected to the starting system of the electric machine.

0 Unlike the well-known, in the proposed electric machine, the source of compressed air is made in the form of two air-blowers located on both sides of the stator, each air heater consists of a pressure wheel and a guide vehicle, the pressure wheels are fixed on the shaft and are located in the stator grooves, air-guiding the devices are located on the ends of the stator,

0, the working gap of the gas-magnetic support on both sides communicates with the pressure cavities of the air-blowers, and an air receiver is connected to the supply channels through. control valve; The valve is connected to the motor starting system.

Injection wheels, in combination with guide vanes, form a dual air-blower that delivers compressed air to the gas-magnetic support. With

In this way, the air blower is an integral part of the entire device (the wheels are mounted on the rotor, and the guides are located on the ends of the stator). Thus, the electric machine itself

5 is driven by an air blower. In other words, the power of the gas-magnetic support is provided by the electric machine itself and does not depend on external conditions. A receiver connected to the power supply channels of the support through a controlled channel provides the support with air at the time of the start of the electric machine. Replenishment of air in the receiver occurs in the established mode of operation,

5 The drawing shows an electric machine, axial section.

The electric machine contains a laminated magnetic circuit of the stator 1 in the housing 2. The three-phase distributed winding 3 is laid into the slots of the magnetic core.

The cylindrical bore of the stator is fitted with a cylindrical rotor 4, which is made integral with the shaft 5. Next, pressure wheels 6 are fixed on both sides of the rotor, at least one on each side. To ensure sufficient pressure, the air blowers are supplied with two wheels (as shown in the drawing). The frontal parts of the winding are filled with compound 7, which forms the housing of the superchargers, since the wheels are mounted in the end hole of the stator, i.e. in the compound. In the aforementioned bores, guide vanes of air-blowers are installed, made in the form of grids 8. At the same time, one of the grids (closest to the stator) is fixed at the end of the bore. Radial channels 9 are made in the body of the magnetic core, which provide gas lubricant supply during the device start-up and its withdrawal during rotation at operating speeds. These channels are interconnected by an annular bore 10 in the housing. On the working surfaces of the rotor and the stator, annular teeth 11 are made, which are filled in with a non-magnetic antifriction material 12 to form a non-magnetic layer 13 on the stator. The working gap between the surfaces of the rotor and stator, i.e. The working gap of the gas-magnetic opera is connected on both sides with the pressure zone 14 of the air intakes. An annular sweep 15 and chevron grooves 16 that are not communicating with it and between themselves are made on the working surface of the rotor.

Electric machine works as follows.

Scheme gas through a controllable valve 17, an air vent and an annular bore 10 in the housing 2, radial channels 9 and an annular groove 15 on the rotor 4 are fed into the working gap between the rotor and the stator. At the same time, the rotor 4 floats on the gas lubricant layer. After the lithane is fed into the winding 3, the rotor 4 begins to rotate in the field of gas and electromagnetic forces, ensuring the movement of the shaft 5 with the wheels of the 6 superchargers mounted on it, which supply air to the working gap of the electric machine. At the same time, air with pressure PI falls on the blades of the first wheel 6. At the exit of the blades, the air pressure becomes P2 and it is fed to the blade and the fixed guide grate 8, where a new flow is formed, which is directed to the second wheel. At the exit from the second wheel, the air pressure becomes RH, and it feeds a gas clearance of the gas-magnetic support through the cavity 14. The number of stages of the injection system is determined by the pressure that must be created at the entrance to the working clearance of the support, and is determined by the dependences given. When the rotor reaches 4 rotational speeds, ensuring (it has sufficient flow and pressure of air to build up the magnetogasdynamic support, valve 17 turns off the external source of the receiver and ensures that compressed air is freely released through the radial channels 9 and the outlet in the housing 2 to the atmosphere 5. Threshold value values are determined by the dependencies below.

The radial magnetogasdynamic suspension of the rotor is provided by the interaction of the lifting forces of the gas lubricant layer, i.e. compressed air injected into the gap between the rotor and the stator, and the electromagnetic forces of attraction of the rotor to the stator, created by the working electromagnetic field of the stator.

The stability of the radial suspension of the rotor is caused by the presence of a nonmagnetic layer 13 on the surface of the stator facing the rotor. This layer provides for the separation of the gap on the magnetic and gas, and the magnetic consists of the magnitude of the gas gap and the thickness of the nonmagnetic layer 13. In the axial direction, the electromagnetic suspension of the rotor is provided by the non-contact interaction of the ring teeth 11. performed on the rotor and stator faces facing one another. .

Shearon grooves 16

0 on the outer surface of the rotor, providing additional throttling of the gas lubricant flow, cause an increase in the rigidity of the magnetogasdynamic suspension at a constant pressure

5 boost. Thus, the presence of grooves makes it possible to provide the necessary rigidity of the suspension with a reduced boost pressure. The groove on the rotor provides a free flow of compressed gas from the gap and

0 reduces the stagnant exit zone.

When changing the direction of rotation of the rotor, the electric machine remains operable. In this case, the gas lubricant is sucked through the hole in the box.

5, the radial channels 9 into the working gap and ejected through the bores 7 in the shells.

Estimated calculation of gas lubrication flow rate, provided by one stage, can be carried out by the expression

Q YG2 Kv2 D2t) 2 U2. mi / s

where 3.14; r 0,8-0,9;

Kva compressibility factor, equal to the ratio of the density at the output and the input, T.e.Kv2 g.

Q2 "1,4pri -1.5

, 77 when 2;

Da - outlet wheel diameter, m; 02 - the width of the blades at the exit of the wheel, m

B2

Sh

0.02-0.07;

rp is the coefficient of flow, taken p 0,2 0.28 when installing blades at the exit fk - 90 °;

7TD2 P

U2 -60

m / s, circumferential speed on

diameter;

n - wheel rotation frequency, rpm.

The ratio of pressure in the stage is determined by the expression

 1+ (1 + / ZPR + Ap) ctgfo (K - 1) C%. D2 U2 I G2 KV2 BL2 K R T „JJ

where P2, PH - the pressure at the outlet and inlet f wheel

 +

 (0.12 + 0,) / (YuOO p, it is possible to accept 0.86 with Dg 90 °; K2 1-f81p #;

G2 - the number of blades (8 - 20);

k is the adiabatic index (for air 1.4);

Tn is the temperature at the entrance to the stage;

R is a gas constant, for air 287 J / kg K;

J / gender - polytropic efficiency is 0.7 - 0.85.

The cost of gas compression can be roughly determined by the expression

i RT (k i (± - D - zrj (gk-1 ..

where CD is the specific work of adiabatic compression in the step.

As can be seen from the above expressions, the gas lubricant consumption and the boost pressure increase with increasing rotor speed, and therefore, in the proposed machine, the rigidity and, consequently, the stability of the magnetogasdynamic suspension increase with increasing rotor speed. This distinguishes the proposed machine from the known one, since in it, with an increase in the rate of waxing, the stability decreases and to increase it, an increase is necessary

boost pressure provided by an external power source.

The proposed electrical machine motor-bearing retains all the positive qualities of the known device, since

in one structural unit, it combines the functions of an electric machine and a magnetogasdynamic support, and the construction contains one working gap, the gap of an electrical machine and magnetogasdynamic support.

However, the proposed electric machine is superior to that known in that it is an autonomous system with a uniform power source, and a known machine requires the supply of electricity and compressed gas. Moreover, the cost of supplying compressed gas from an external power source, taking into account the efficiency of a pneumopump and losses in the pipeline, exceeds

the cost of boost gas lubricant in the proposed technical solution. In addition, the autonomy of the proposed design extends the scope of application of an electric machine.

Thus, the proposed design of the motor-bearing electric machine ensures the autonomy and reliability of its operation while simultaneously increasing the rigidity of the gas-magnetic rotor suspension.

Claims (1)

Invention Formula An electric motor bearing motor comprising a stator in the form of a laminated magnetic circuit with a three phase distributed winding and a rotor mounted in a stator on a gas-magnetic support associated with a source of compressed air, characterized in that, in order to increase reliability and provide autonomy, the source of compressed air is made in the form of two air-blowers installed on both sides of the stator, each of which contain at least one injection / ops. which is located on the shaft and located on the bore of the end face of the stator, and the guide apparatus located on the end of the bore, while the working gap of the gas-magnetic support on both sides communicates with pressure air cavities and gels, and an air receiver is connected to the supply channels of the support through a controllable valve connected to the electric machine start system,