SU728003A1 - Device for measuring the temperature of rotating components of machines - Google Patents

Description

I

This invention relates to a measurement technique.

A device for measuring the temperature of rotating machine parts is known, which contains movable inductance cat-shafts placed on a rotating part and thermocouples connected to them, fixed inductors and indicator P1Gbor l.

In the described device, a single measurement and recording of the temperature at all controlled points is performed for the shaft rotation. The current flowing in the thermocouple circuits excites the magnetic field in the moving coil, which, when the rotor rotates, induces an emf pulse in a fixed coil with an amplitude proportional to the measured temperature. At the same time, the ammeter depends on the resistance of the measuring circuit: the thermocouple is a moving coil, the icoTopoe changes during operation and thereby introduces significant errors in the temperature measurement.

The aim of the invention is to improve the accuracy of temperature measurement.

The goal is achieved by the fact that fixed compensation coils connected to an adjustable DC source are inserted into the proposed device, the compensation coils are provided with U-shaped cores, the ends of which face the moving coils and lie in the same plane as the compensating coils.

Such an embodiment of the device makes it possible to increase the accuracy of temperature measurement.

FIG. schematically depicts the proposed device; in fig. 2 - the same, top view; on. FIG. 3 (a, b, c) -form pulses.

The device contains a light textolite disk located on the shaft 2 of the controlled part with movable coils 3, to which thermocouples 4 are connected. The stationary coils 5 and 6 are mounted coaxially with the coils 3. The fixed compensatory catuips 7 and 8 are connected to an adjustable source of 9 direct current . The stationary coils 5 and 6 are connected to the indicator 10. The compensated coils are made in the form of cylindrical coils 11 with a U-shaped core 12, the ends of which 13 are located in the same plane as the forming compensation coils. The device works as follows. Changing the current supplied from the source 9 to the coils 7 and 8 in the corresponding polarity (so that the compensation pulse is opposite to the measured EMF), reduce to zero the amplitude of the pulse induced in the fixed coils by the current of the thermocouple of the channel. And according to the current value of the compensation coils, the temperature of the rotating parts is judged. . The time of current compensation in the thermocouple circuit when using a contactless current collector can be limited to t, which greatly facilitates the technical solution of the problem, since to compensate the thermocouple current during the measurement period, it is enough to build a rectangular impulse of reverse polarity telnosti. When adding a thermocouple direct current and a compensating pulse in the thermocouple circuit over a period of time, there will be no current, therefore, during the compensation period, the magnetic field of the moving coil and the EMF pulse in the stationary will be zero. The condition that must be fulfilled is the simultaneous transfer of energy from the moving coil to the stationary and compensating impulse from the compensation system to this thermocouple circuit. This condition is fulfilled automatically if the KaTSffiKa nepopovykas and her compensation system are combined in space. To transfer a compensating pulse to the thermocouple circuit, the same moving coils are used, which transfer energy from the thermocouple to the fixed coil. As a source of energy for creating a cocyucing impulse in a moving coil (i.e., in a thermocouple circuit), in the proposed device coils of a special shape and dimensions, powered by continuous current, are used. Using such coils, a cosensing pulse of near-rectangular shape is created (Fig. 3c). It is induced by JB moving coil 3 (Fig. 3a) if it crosses When moving in the direction of a fixed magnetic field, the axial component of which ( i.e. the component directed along the axis of the fixed coil has the shape shown in FIG. 3 .6. Such a field is created by a cylindrical coil with a P-shaped heart, rs

Claims (1)

728003 of which lies in a plane parallel to the plane of rotation of the moving coils, and is directed tangentially to the projection onto this plane of the trajectory of movement of the centers of the moving coils (Fig. 3 a). The ends of the core facing the moving coils. In this case, the middle of the compensation coil should coincide with the axis of the fixed coil (Fig. 1 and 2). The length of the rectilinear portion of the pulse B (Fig. 3c), ceteris paribus, is maximized if the ends of the core compensating the coil coincide with its generator. In order to obtain a length E of the compensating impulse of at least three diameters of the moving coil (which is necessary to fully compensate the signal during the measurement period), the length of the compensating coil must be at least six diameters. In order to eliminate the effect of axial displacement of the moving coils relative to the stationary ones, in the proposed device two compensating and stationary coils are installed symmetrically in relation to the moving coils. Thus, the introduction of compensation coils into a device for measuring the temperature of rotating parts made it possible to increase the measurement accuracy by eliminating errors caused by changes in the resistance of the measuring circuit, as well as by eliminating the scaling operation of the output signal. Formula of the invention A device for measuring the temperature of rotating machine parts, containing movable inductors placed on rotating parts and connected to them. thermocouples, fixedly mounted inductors and an indicator device, characterized in that with the aim of increasing the accuracy of temperature measurement, a fixedly mounted compensation coils are inserted into it, which are connected to an adjustable DC current source, and side of the moving coils and lie in the same plane with the forming compensation coils. Sources of information taken into consideration in the examination I. USSR author's certificate No. 180833, cl. G 01 K 13/08, 1965 (prototype). Ll j X2. Th five