SU972275A1 - Magnetoelastic torque converter - Google Patents

Description

(54) TORQUE MAGNETIC ELASTIC CONVERTER

one

This invention relates to load measuring technique.

A magnetoelastic torque converter is known, comprising a ferromagnetic shaft, a fixed annular electromagnetic system, and a measuring circuit 1.

However, this transducer does not provide the required measurement accuracy.

The closest in technical essence and the achieved result to the proposed is a magnetoelastic torque converter containing a ferromagnetic shaft, a stationary ring electromagnetic system, the plane of the magnetic conductors of which are at an angle of 45 ° to the axis of the shaft and at an angle of 90 ° to each other, and the windings are laid in the grooves of the magnetic cores concentric with the axis of the shaft, and the bridge measuring circuit 2.

In the known converter, there are significant losses in the shaft to eddy currents, which increase the reactive component of the shaft's magnetic resistance and, accordingly, its total magnetic resistance. This leads to a decrease in inductance and inductance of the windings of the oil pipelines, which reduces the sensitivity and accuracy of measurements.

The purpose of the invention is to increase the sensitivity and accuracy of measurement.

This goal is achieved by the fact that in the converter the ferromagnetic shaft is made of cylindrical rods inscribed in the circumference of the shaft and rigidly fixed at the ends between them.

ten

FIG. 1 shows the transducer, a general view; in fig. 2 is a section A-A in FIG. one.

The magnetoelastic torque converter contains an elastic ferromagnetic shaft 1, which is made of cylindrical rods 2 of circular cross section inscribed in the circumference of the shaft. The rods 2 are rigidly fixed at the ends between themselves with the help of cylindrical sleeves 3. The rods 2 of the shaft 1 cover two annular gauges 4 and 5 of electrical sheet steel, the planes of which are at an angle of 45 ° to the axis of the shaft and at an angle of 90 ° to each other. Both stators are fixed in the housing 6, in bearings of which the bushings 3 of the shaft 1 are located. In the slots of the annular stators 4 and 5, loop windings 7 and 8 are disposed along their inner circumferences at an angle of 45 ° to the stator planes. Winding 7 and 8 are included in the shoulders of the measuring bridge, powered by the voltage U.

Magnetoelastic transducer works as follows.

In the absence of a steep torque (M 0) and complete isotropy of the rods 2 of the shaft 1, the measurement circuit is balanced and the output signal U2 is zero.

When a torque () is applied to the ferromagnetic shaft 1, the rods 2 are twisted and compressive and tension stresses occur in them, directed to their axes and to the axis of the shaft 1 at an angle of 45 ° and at a right angle to each other.

Under the action of tensile stresses, the magnetic permeabilities of the rods 2 of the shaft 1 increase in this direction, and under the action of compressive stresses in the perpendicular direction, they decrease. This leads to an increase in inductive and, therefore, impedance, for example, the winding 7 of one stator 4 and to a decrease in the inductive and impedance winding 8 of the other stator 5.

As a result of the anisotropy of the shaft rods, the resistances of the bridge shoulders change and a voltage proportional to the torque U2 KM appears at the output.

When the sign of the moment is reversed, the sign of the change in the magnetic permeabilities of the rods 2 in the mutually perpendicular planes of the shaft 1, enclosed by ringed stators with windings, changes. The resistance of the winding 7 of the stator 4 decreases, and the resistance of the winding 8 of the stator 5 increases. The signal at the output of the bridge circuit changes its sign.

The use in the proposed magnetoelastic converter of the shaft torque, which is made of cylindrical rods of circular cross section, inscribed in the circumference of the shaft and rigidly fixed at the ends between them, will reduce eddy current losses and thereby reduce the reactive component of the magnetic field.

0 resistance of the shaft and, accordingly, its total magnetic resistance. This leads to an increase in inductances, inductive and impedances of the stator windings, which increases the sensitivity and accuracy of the transducer measurement.

Claims (2)

Invention Formula A magnetoelastic torque converter containing a ferromagnetic shaft, a stationary annular electromagnetic system, the magnetic cores of which are located at an angle of 45 ° to the axis of the shaft and at an angle of 90 ° to each other, and the windings are laid in the grooves of the magnetic cores of a central axis of the shaft , characterized in that, in order to increase the sensitivity and accuracy of measurement, in it the ferromagnetic shaft is made of cylindrical rods inscribed in the circumference of the shaft and rigidly fixed  at the ends between each other. Sources of information taken into account in the examination 1. Ginzburg V. B. Magnetoelastic sensors. M., “Energie, 1970, p. 57. , 2. USSR author's certificate No. 732694, cl. G 01 L 3/10, 10.04.78 (prototype). U ///// 1 ////// 77 /////////////////////// /// 7U V4MVCS sy 44Zv yVxV NNN -isl / yiFl / g .f