RU1791924C - Thyratron motor - Google Patents

Abstract

Usage: magnetic and optical disk drives, 1 tape drive other devices. SUMMARY OF THE INVENTION: An electric motor comprises a stator with a winding connected to a semiconductor switch, a rotor with an inductor, a rotor position sensor and a tachomeric winding. rotor position. 2 ill.

Description

The invention relates to the field of electrical engineering, in particular to the section of brushless DC electric machines, and can be used in the drive of disk storage devices, tape recorders, players.

A valve motor is known, comprising a stator with a core winding and a rotating inductor consisting of a steel frame, to which four permanent magnets are glued, and pole tips are glued to the latter. A magnetization system of the rotor position sensor, consisting of two sector magnetic shunts and two concentric arcs, is attached to one end surface of the inductor. The rotor position sensor is mounted on a special plastic cover and consists of a closed magnetic circuit on which the primary and secondary windings are located. The latter, through the control unit, depending on the position of the rotor, opens the keys of the switch to which the core winding is connected.

Engine i is distinguished by structural and technological complexity. In addition, it does not have a tachometric winding, and if it is used on an automated electric drive, an additional tachogenerator is required, which leads to even more complication and an increase in the axial length.

A valve motor is also known, consisting of a stator with an m-phase root winding connected to the network via a semiconductor switch, and a rotating inductor. On the stator there is a rotor position sensor made in the form of a ferromagnetic screen to which m open ferromagnetic cores with two windings each are attached against the end surface of the inductor. These windings are connected in pairs by a differential circuit with half-wave rectification and connected to a high-frequency voltage source through a resistor, from which the rotor position signal is taken, and an electronic key.

ate

WITH

The motor contains m inverters, m electronic zero-organs through which the signal about the rotor position is supplied to the control circuits of the switch, as well as a differentiator, integrator and comparator.

The engine has a number of significant drawbacks associated with the fact that at the output of the rotor position sensor there are two signals of the same frequency, but shifted 180 ° relative to each other: a signal about the rotor position; varying values depending on asthma in the area; , a rotational emf signal, the magnitude of which varies with the rotational speed. . : ..-. ,

At a low speed, when the emf of rotation is negligible, each of the m null organs (comparators) produces a rectangular pulse with a duration of a 180 °. Since at m -3. These pulses are shifted relative to each other by 120 °, then. every 60 ° the switch keys are switched,. the inter-commutation period к k, during which the rotor rotates from a certain minimum angle between the axes of the MDF р F and the magnetic flux Φ to the maximum 02 without commutation in sections (phases) of the core winding, is also equal to C °. This inter-switching period is ideal for a three-phase bridge circuit of a switch;; switch;; :: -. ;; . ;;: .. ..;. . /; .

 . As the speed increases, the EMF of rotation increases, therefore, the resulting signal at the output of the rotor position sensor decreases. Since the threshold voltage of the null organ is constant, in this case its momentum appears later and disappears earlier than at. lack of emf rotation, i.e. The n-pulse momentum of a null organ decreases as the speed increases. This leads to an increase in 6 and a decrease, as a result of which the average moment decreases and the pulsation of the moment increases. Therefore, the unevenness of rotation also increases.

. Owing to a decrease in the m-moment, the power given by the engine decreases with almost constant losses, i.e. Engine efficiency is reduced. Thus, due to the harmful effect of the emf of rotation. On the operation of the null-body, and therefore of the commutator, the technical and economic performance of the engine is deteriorated: efficiency is reduced; engine volume increases per unit of torque (power at a given speed).

At a certain speed, and the average moment is 0, i.e. the engine becomes generally inoperative. To ensure operability

in this case, in the prototype, it is possible to switch to control of the switch by a rotation emf signal, for which m inverters, an electronic switch, a differentiator, an integrator and a comparator are provided, which leads to a significant complication and a decrease in reliability. ..

In addition to these drawbacks, the engine cannot be used in an automated electric drive due to the absence of a signal proportional to the rotational speed.

An object of the invention is to increase reliability.

0 The goal is achieved in that in an electric motor containing a stator with an m-phase winding connected to the network through a semiconductor switch, a rotor with permanent magnets, m open

5 ferromagnetic cores with lugs located around a circle near its end surface, each of the cores is connected to an annular magneto-conductor, a magneto-sensitive element is installed between them, and a tachometer winding is placed on the annular magnetic circuit. . . Figure 1 shows a valve motor, a longitudinal section; Fig. 2-5 is a section AA in Fig. 1 for a three-phase bipolar motor. ..,. .

The valve motor is worn out of the housing 1, of the bearing shields 2 and 3, of the shaft 4, rotating in bearings 5, s

0 by inductor b, stator 7 with core winding 8 connected to a switch (not shown), ferromagnetic cores 9 located near the end surface of the rotor and shifted relative to each other by

5 120 electric city rods 10 with a magnetically sensitive element 12, for example, a Hall sensor, frame 13c with a tachometric winding 11 mounted on a board 14, which simultaneously serves to perform

0 electrical connections. The tachometric winding 11 can also be placed on the rods 10. Cores 9, rods 10 and pmo 13 form a special magnetic wire for the scattering magnetic flux

5 is a sectional view of which for a three-phase de-pole machine in cross section is shown in FIG. This magnetic circuit can be made of extruded magnetic material with increased specific electrical resistance to reduce losses.

eddy currents. For any number of pole pairs (p 1,2,3,4, ...) the length of the arc of the cores 9 should not exceed 2/3 of the pole division.

The operation of the engine is as follows.

The magnetic flux of the inductor 6 exiting from its cylindrical surface (main flux), interacting with the channel of the Winding core 8, creates a torque. The magnetic flux emanating from the end surface of the inductor 6 (scattering flux) is collected in the core 9 located opposite this pole, and passes through the rod 10, pmo 13 and other cores 9 to the pole of opposite polarity. When the rotor rotates, each of the cores 9 moves in a magnetic field; therefore, the magnetic flux in them, therefore, in the rods, changes. Owing to this, in the windings 11 located on the frame or on the rods, EMFs are proportional to the rotational speed and phase shifted relative to each other, and a signal appears in the magnetically sensitive elements 12, which varies depending on the position of the rotor. The signals of these elements are phase shifted according to the spatial shift of the cores 9 and can be used to control the operation of the switch.

Connection of cores with an annular magnetic core, installation of magnetically sensitive elements between them and size;

The tachometric winding on the ring magnetic core ensures the independence of the signal about the position of the rotor and the tachymetric signal from each other.

Due to this, the emf of rotation does not adversely affect the operation of the switch. In addition, the functional circuit is greatly simplified (there is no need for m inverters, an electronic switch, an integrator, a differentiator, a comparator and a high-frequency power supply), therefore, reliability is increased. At the same time, the design of the motor itself is simplified due to the absence of a magnetic one. The presence of an independent rotation EMF signal allows it to be used to control or control the rotation frequency.

Claims (1)

The claims Fans and electrodes containing a stator with an rn-phase winding connected to the network through a semiconductor switch, a rotor with permanent magnets, m open ferromagnetic cores with tips located around the circle near its end surface, distinguishing both with the fact that, in order to increase reliability, each the core is connected to a ring magnet wire, Between them there is a magnetically sensitive element, and on the ring the magnetic circuit has a tachometric winding. 3 (5 n