SU655038A1 - Linear electric motor - Google Patents

Description

one

The invention relates to electric motors with linear movement, for example, for transport devices.

Linear electric motors are known which contain as a secondary element a strip of metal in which currents are induced by a running magnetic field created by the primary winding 1.

In such electric motors, the transfer of energy to the secondary element is ostaned with the slip frequency, which is energetically unfavorable if there is a large non-magnetic gap in the magnetic circuit of the linear electric motor.

Another linear electric motor is also known, which contains a C-shaped magneto-drive with a coil placed on it and connected to the power supply through a valve switch, and the secondary element in the form of a metal strip 2.

This device is closest to the described invention.

In this electric motor, the primary winding is connected: g: to the source of single-phase alternating current; ; cut anti-parallel controlled valves. The secondary element is a sequence of metal plates separated by non-conducting gaps, the width of which is equal to the width of the plates themselves. With the passage of these plates between the poles of an electromagnet, a repulsion force arises, varying in magnitude and

direction. In order to use the repulsion force as a driving force, it has been proposed to cyclically turn off the primary winding for a certain time and thus ensure that the force is only

one direction. In order to avoid dropping to zero the magnitude of the driving force, it is possible to use, for example, two electromagnets, in which the intervals for switching off windings do not coincide in time.

The design of the linear motor is characterized by significant drawbacks, namely: the need to cyclically turn off the working windings is the reason for poor use

active materials of the electric motor; in the time interval when the winding is turned on, the maximum value of the repulsive effort cannot be used for a long time, since in the process of movement it

varies in size over very wide limits, decreasing as the plates are pushed out from under the poles of an electromagnet, which inevitably leads to a decrease in the energy performance of the electric motor.

The purpose of the invention is to improve the energy performance of a linear repulsion type electric motor.

This goal is achieved by the fact that the electric motor is equipped with additional carrier coils of C-shaped magnetic conductors, while the coils placed on the magnetic conductors arranged through the pole separation are interconnected in series, and the secondary element is made with rectangular openings whose width and the distance between which is equal to half the pole division.

In addition, the electric motor has additional coils located on the magnetic cores coaxially with the first coils and interconnected similarly to them.

The magnetic cores of the electric motor in the vertical direction cover the part of the secondary element located above the bottom edge of the holes.

FIG. 1 shows an electric motor, a view; in fig. 2 is a cross section A-A in FIG. one; in fig. 3 is a diagram of the connection of coils located on the C-shaped magnetic cores of the primary element, and also shows the pattern of distribution of the magnetic field lines created by these coils and the direction of the currents of the secondary element; in fig. 4 shows a constructive version of an electric motor with additional coils, placed on the magnetic cores of the primary element; in fig. 5 is a diagram of a motor switch with a single-phase AC power supply; in fig. 6- graphs of electromagnetic processes of an electric motor as a function of time, in the case of using the switch of FIG. five; in fig. 7 is a variant of a switch with DC power supply; in fig. 8 shows plots of electromagnetic processes of an electric motor as a function of time, in the case of using a switch, but FIG. 7

The linear motor is composed of a primary element, made in the form of a series of C-shaped magnetic cores 1, on which the dimensions 1 are located on coils 2, and a secondary element (guiding blade 3 located in the gaps of C-shaped magnetic cores. Secondary element 3 is a flat a metal strip with rectangular openings (windows) 4, one space apart from another by a distance equal to the half pole division — the electric motor, and the width

t

also - Thus, the total width of the window and. the metal bridge is pole division t. The secondary element can be assembled, for example, from individual parts. Their docking lines are shown in FIG. 1 point, iricheic provision of electrical contact between adjacent parts is optional. The coils placed on the cores arranged through the pole division and the magnetic conductors interconnect with each other sequentially and constitute the primary winding sections. FIG. 3 shows as an example the four-pole design of an electric motor with four sections 5, 6, 7 and 8 of the primary winding. Obi, its number of coils in the section is equal to the number of poles of the electric motor. Neighboring coils of this section, directly connected to each other, are included in opposite. When flowed around by current, they create magnetic fields of different directions, the lines of force of which are closed in planes perpendicular to

to iloskosy secondary element.

Thus, the number of C-shaped magnetowires within the pole division is equal to the selected number of sections of the primary winding. The total number of magnetic circuits is equal to the product of the number of sections and the number of poles, in this sixteen magnetic circuits.

FIG. 4 shows a constructive version of an electric motor, in which

C-shaped magnetic cores placed additional coils, coaxially with the first, interconnected similarly to them, made of wire of the same cross section and with the same number of turns and forming additional sections, for example 9. The sections of the same name are marked with dots.

FIG. 5 shows one of the possible switch circuits of an electric motor powered by a single-phase alternating current network, designed to work together with an electric motor with two coils on each magnetic core. Section 8 is included in the diagonal of the bridge circuit formed by controlled gates (thyristors) 10–13. Additional section 9 is included in the diagonal of a similar bridge circuit formed by thyristors 12-15, and thyristors 12, 13 are common for two bridge circuits. Similarly, the remaining sections and additional sections of the primary winding are included.

FIG. 6 shows the graphs of electromagnetic processes of an electric motor.

as a function of time. Here, 16 is the voltage source of the food; 17, 18 are sequences of switch thyristor control pulses that are synchronized with the power supply and time shifted by half a period. The pulse sequence 17 goes, for example, to the control electrodes of the thyristors 10, 11 (Fig. 5), the sequence 18 goes to the control electrodes of the thyristors 14, 15. The control electrodes of the thyristor 12, 13 are fed to the impulses1) CE of both sequences) i.e. in each half period of the supply voltage). Similarly, the valves of the remaining sections are controlled.

The control voltage 19 generated from the signals of the linear displacement sensor is controlled by a logic circuit that switches switching pulses 17, 18 pulses from one pair of thyristors of the winding section to another. Position 20 in FIG. 6 denotes the continuity of current pulses, for example, in section 8, position 21 - the sequence and current pulses in the additional section 9.

FIG. Figure 7 shows a variant of a circuit with a DC power supply. Gates (thyristors) 22 - 25 form an inverter bridge circuit, the diagonal of which includes a switching capacitance 26.

Section 8 and additional section 9 are included in the two arms of this bridge circuit and are combined at a common point with their opposite clips. The electromagnetic processes of the electric motor are illustrated in this case by the graphs depicted in FIG. 8, where 27 is a sequence of pulses of a master oscillator, adjustable in frequency; 28, 29 are sequences of switch thyristor control pulses similar to sequences 17, 18 of FIG. 5, but, unlike them, obtained by dividing the frequency of the master oscillator by two. At a fixed point in time, a sequence of 28 pulses is supplied, for example, to the control electrodes of thyristors 22, 25, and a sequence of 29 - to control electrodes of thyristors 23, 24, due to which the magnetic flux formed by the total action of two sections 8, 9 will change with a frequency twice as low as the pulse frequency of the master oscillator.

Control voltage 30 is generated from the signals of the linear displacement sensor; it is similar to voltage 19 in FIG. 6. The position 31 in FIG. 8 denotes a sequence of current pulses, for example, in section 8, and position 32 indicates a sequence of current pulses in section 9.

The motor works as follows.

The switch (Fig. 5) provides, by the signals of the linear displacement sensor, switching of currents in the sections of the primary winding, which is performed as follows. When a sequence of control pulses 17 is applied (Fig. 6) to thyristors 10-13 in one of the half-periods of the supply voltage, the current is closed, for example, along a circuit: thyristor 10, section 8, thyristor 13. In the next half-period, the polarity of the supply voltage on the glue , mma.s changes and when a sequence of 18 control pulses is applied to the thyristors 12-15, the current flows through the circuit: thyristor 15, doG1 section 9, thyristor 12. Therefore, the current 20, 21 current pulses in sections 8, 9 have a different direction ( if we assume relatively similar clips hank). The magnetic flux created by the cumulative effect of the currents in sections 8, 9 is variable, pulsing with the frequency of the supply. If you switch the sequence of 17 control pulses from thyristors 10, and to thyristors 14, 15, and sequences 18 from thyristors 14, 15 to thyristors 10, 11, the total magnetic flux of sections 8 and 9 will revert to 180 el. hail, (moment t in fig. 6).

A similar effect of phase reversal of the magnetic flux sections 8 and 9 is also provided in the switch shown in FIG. 7, if the sequence 28 of control pulses is switched at the moment

t from thyristors 22, 25 to thyristors 23,24, and the sequence 29 from thyristors 23, 24 to thyristors 22, 25.

Similar to switching currents in sections of the primary winding during movement

the primary element with respect to the guide web is as follows.

Every time when the magnetic cores with coils placed on them

the sections are located on the lateral border of the rectangular opening (window) of the guide web when the magnetic conductors run from the window side onto a metal jumper between two adjacent

by windows, the control circuit based on the signals of the linear displacement sensor (whose functions are similar to the functions of the angular position sensor in electric masses with a rotating rotor) changes the polarity of the control voltage 19 or 30. This leads to the indicated switching of the sequences 17, 18 (or 28, 29) pulses from one pair of thyristors of this section to another. In this case, the sensor

Linear movement, such as a transformer, must have a number of output windings equal to the number of sections of the primary winding of the electric motor, and ensure that the control system forms the corresponding number of control voltages.

This method of connecting the coils in sections and cyclically switching the currents in them is provided during the movement

the formation at each instant of time within any neighboring pole divisions of magnetic fields of different directions, whose lines of force are closed in planes perpendicular to the guide web. Mutual spatial.

7

The orientation of the magnetic currents created by the joint action of all sections of the nervous winding and the currents generated by the currents induced in the short-circuited contours of the magnetic field remains in the process of movement practically unchanged (as shown in Fig. 3). The primary winding creates a linearly moving magnetic field that simultaneously pulsates with the switching frequency of the thyristors (when powered from a non-direct current source, it is the frequency of the network).

The operation of an electric motor is characterized by the following feature. If the C-shaped magnetic conductors move relative to the secondary EuTemeit, the guide track, for example, right to the right, then the magnetic field created by the currents of the primary winding moves relative to the primary element at the same speed from the right pale and therefore motionless relative to short-circuited circuits with currents induced by in the guideway. (The exception is extreme contours, in connection with which the preferred design of an electric motor in a multi-pole version). Thus, in the first approximation, it can be assumed that only transformer EMF is induced in the circuits of the guiding bar, while the emf of the movement is induced mainly only in the primary winding, in what it can be called the winding of the core. In the process of moving from the B-speed to the secondary element, a relatively small part of the consumed power is transmitted by the electromagnetic churn. For a linear electric motor, this is a significant advantage if we take into account the inevitably large non-magnetic gap in its magnetic value.

The interaction of magnetic fluxes created by the primary winding (core winding) with the currents in the short-circuited contours of the guide sheet leads to the emergence of a moving force, which by its nature is close to repulsion. The presence of a large non-magnetic gap substantially reduces the inductance of the winding sections of the core, which makes it possible to use a relatively high frequency of power. This, in turn, allows you to create a high-speed electric motor, improve the transfer of electromagnetic energy to the secondary element and weight and dimensions.

The magnetic guides cover along the verticals a guide sheet from its upper edge to the lower edge of rectangular holes. Thus, the upper (horizontal) bridges above the windows are also in the zone of action of the magnetic fluxes of the C-shaped magnetic cores, and the interaction of the indicated magnetic fluxes with the currents in these sections leads to

Diet to 1; the impact of the structure .Uijonieii effort, acting on the nerve element from the bottom up. This component is provided both in the process of movement, and at speed, a rabbi of zero, and can be used both for unloading guide rails and, in principle, for creating an electrodynamic suspension system. In this case, such a switchboard essentially turns out to be structurally aligned with the linear motor itself, and its operation does not require the consumption of additional energy from the power source.

Reverse and speed control can occur due to the primary element of the linear variable sensor relative to the primary element of the electric motor. Speed control with a power supply of the switch from the AC network can also be carried out by varying the phase shift of the thyristor control pulses relative to the supply voltage (pulse-width control), and

when powered from a DC source, by changing the frequency of the following pulses (frequency controlled). The air / button is also a combined speed control.

Presented in FIG. The 5, 7 circuitry of the commutators ensures good utilization of the power valves and excludes the possibility of the occurrence of a short circuit of the source of the titanium.

This design provides for both the movement of the primary element relative to the fixed guide web and the reverse non-displacement. In the latter case, it is possible to create an electric motor with a wrench, for example, a disk rotor with openings, half a pole wide, enclosed outside by C-shaped magnetic cores placed on

they are wound core, as well as the possibility of creating an electroplating conveyor or an electric tracked drive.

The technical and economic feasibility of applying the proposed design consists in increasing the energy and weight-related indicators of the linear electric motor of the repulsion ion, and also in improving the use of its active materials.

Ph o rm lla invented and

1. A linear electric motor containing a C-shaped magnetic circuit with a coil spaced on it, connected to

the power source through the valve switch, and the secondary element in the form of a metal band, characterized in that, in order to improve the energy performance, it is equipped with an additional c.

The magnetoconductors, in this case, the coils placed on the magnetic circuits located across the zero pole are interconnected sequentially, and the secondary one;) the element is made with rectangular openings, the width of which and the distance between them are equal to half pole polar.

2. Electric motor According to claim 1, it is distinguished by the fact that it is equipped with additional coils located on the magnet tubes and coils of the first coils and

with each other similarly to them.

3. Electric motor on PP. -2, in contrast to the fact that the magnetic pipelines in the vertical nanowelleni cover the secondary element located above the bottom edge of the holes.

PicT04HHKH information,

taken into account in the examination

1. Author's certificate of the USSR AO 195540, cl. H 02 K 41/02, 1963.

2. The patent of Germany No. 2029462, cl. 21 d 23, oyublpk. 1973.

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