SU1388705A1 - Magneto-modulation angular displacement transducer - Google Patents

Abstract

. The invention relates to a measurement technique and is aimed at improving the accuracy of converting angular displacements by reducing the effect of technological manufacturing errors and temperature instability of the slope of the conversion characteristic of an inductive sensor, which contains a stator 1 made of a nonmagnetic material and having 2 s evenly spaced around the circumference pressed into them ferromagnetic sleeves 3-8. The bushings are covered by coils of sections of 9-14 T-phase windings, the inductive resistance of which, depending on the degree of magnetization of the bushings, is determined by the angular position of the rotor 15, having adjacently located hard magnetic 16, 17 and magnetically soft 18, 19 poles. The winding sections of the inductive sensor can be located in two rows of primary and secondary openings with bushings inserted into them, thereby providing a more gradual change in their inductance over the time the rotor magnetically hard pole passes past them 15. B result, the shape of the phase voltages formed at the output of the sensor, it is more close to sinusoidal, which improves the accuracy of the conversion of angular displacements. 3 il. i SL

Description

f3

//

fQ

DO 00

00

about

SL

ft

The invention relates to a measurement technique and can be used to convert a rotation angle into an electrical signal.

The purpose of the invention is to increase the accuracy of a modulating-numbered angular displacement sensor by reducing the effect of technological manufacturing errors and the temperature instability of the steepness of the output characteristic of the sensor on the modulation depth of the output signal.

FIG. 1 shows a constructive embodiment of a magnetically modulated angular displacement sensor with a number of phases in FIG. 2 - the same, with double the number of holes in the stator; in fig. 3 is a diagram of the connection of the sections of the t-phase winding at.

The magnetically modulated sensor, the angular displacement contains a cylindrical stator 1, made of non-magnetic material and having evenly spaced around a circle corresponding to its average diameter, holes 2, into which ferromagnetic sleeves 3-8 are pressed, covered by coils of sections 9-14 of three-phase winding, respectively. In the center of the stator. 1 (coaxially with it) there is a four-pole rotor 15 with two adjacent magnetic-hard poles 16 and 17 and two adjacent magnetic poles 18 and 19 located by a magnet.

In a sensor with additional holes, 20 ferromagnetic sleeves 21-26 are pressed into additional ones. the holes 20, which are located along the same circumference as the main holes 2, and adjacent thereto, so that sections 9-14 of the three-phase winding cover the adjacent walls of the adjacent sleeves 3 and 21, 4 and 22, 5 and 23, 6 and 24, 7 and 25, 8 and 26, respectively. The pairs are diametrically located: sections 9 and 12, 11 and 14, 13 and 10 form the corresponding phase of the three-phase winding and are connected to the AC power supply 27.

The magnetically-modulated angular displacement sensor operates as follows.

When the sensor windings are connected to the AC power supply 27, the voltage of the source 27 is distributed between sections 9 and 12,

13 three-phase winding from their inductive co5

0

five

0

five

resistance x j. The output signal is removed from the points A, B and C of the joint of diametrically located sections connected in pairs. The inductive resistance of each section is determined by the magnetic state of the ferromagnetic bushings on which the corresponding section is placed.

For example, with the rotor 15 position indicated in Fig. 1, corresponding to the angular position c1.-0, the sleeve encompassed by section 14 is in an unsaturated state, with the result that inductive resistance X of section 14 is maximal. When turning the rotor 15 counterclockwise

0 arrows sleeve 8, covered by section 14, saturates, reducing inductive resistance X., section 14. When the rotor 15 rotates through an angle di -9G °, the sleeve 8 defining the inductance of section 14,

reaching, t maximum, since the entire magnetic field of the rotor 15 is closed through it. In this case, the inductive resistance X of section 14 is minimal and

0 remains so with the further rotation of the rotor 15 to the angle oLy120 °. When the rotor rotates from 0 to 120 ° C (i, 210 ° C, the magnetisation of the hub 8 decreases and, as a result, the inductive resistance increases

14

to the maximum. In the range of angles from

° to 360 inductive resistance

X,

remains maximized and

f4 value.

Section 11 is diametrically opposed to section 14; therefore, changes in its inductive resistance X .. occur with a phase shift of 180 ° with respect to X ,. Periodic change of X., And X, shift

eleven

180 ° in phase, causes a redistribution of the voltage of the power supply source 27 between these sections, as a result of which the high-frequency supply voltage at point B is modulated with the rotation frequency of the rotor 15.

Similarly, but with a phase shift of 120 ° and 240 °, the inductive resistances of the other sections of the three-phase winding, and consequently, the voltages at the points A and C of the connection of the sensor winding sections, change. As a result, the output sensor / j

18.19

srig.1

GT

{

i

i A 0c

srig.Z

heГ7

i

Claims (2)

Claim 5 1. A magnetomodulating angular displacement sensor containing a cylindrical stator with uniformly spaced around a circle corresponding to its average diameter, 10 holes, an m-phase winding, sections of which are located in the corresponding holes, and a four-pole rotor with two adjacent magnetically solid poles and two adjacent 15 located soft magnetic poles, characterized in that, in order to improve accuracy by reducing the influence of technological manufacturing errors and 2Q temperature instability lnosti, it is provided with ferromagnetic bushes pressed into the openings of the stator so that the section of m-phase windings comprise respective sleeve and sta25 torus formed of a nonmagnetic material. 2. The sensor according to claim 1, characterized in that it is equipped with additional ferromagnet bushings 3Q pressed into additional holes that are made in the stator along the same circle next to the corresponding main holes, each section of the m-phase winding covers adjacent walls adjacent bushings. figs!