SU1659863A1 - Apparatus for rotation speed monitoring - Google Patents

Abstract

The invention relates to a measurement technique and can be used to control the speed of rotation of shafts or other working parts of mechanisms and machines. The purpose of the invention is to increase the sensitivity and expand the range of controlled speeds. During rotation of the monitored shaft 3, and with it the conductive cylinder 2, in the latter, eddy currents induce a magnetic flux that reduces the fraction of the flux of the magnetizing core 4. At the same time, as the shaft rotates, the shorting along the cores 4 is redistributed. and 6 of the magnetic flux, the magnetic bias of the core 4 decreases, and the magnetic bias of the core 6 increases. At the output of the measurement circuit, an output signal is recorded, the amplitude of which depends on the rotation speed. In this case, a high sensitivity of the device is ensured with a change in the shaft rotation speed, the range of controlled speeds is expanded. 3 il. ё about с о 00 Os с Fig f

Description

The invention relates to a measurement technique and can be used to control the speed of rotation of shafts or other working parts of mechanisms and machines. The purpose of the invention is to simplify the adjustment of the device, increase the sensitivity of its operation and expand the range of controlled speeds,

Figure 1 shows the device, a general view; Figures 2 and 3 show possible winding connections in the measuring unit.

The device includes a stationary, radially magnetized source of a constant magnetic field 1, a conductive cylinder 2 connected to a controlled working body 3, a first toroidal core 4 with a winding 5, a second toroidal core 6 with a winding 7, a measuring unit 8, a recording device 9, a power supply transformer 10. The device is also equipped with an additional third winding 11, the turns of which cover both toroidal cores 4 and 6. The first toroidal core 4 with winding 5 is located inside that core of the cylinder 2, i.e. on the other side of cylinder 2 relative to the location of the source of a constant magnetic field 1. The toroidal cores 4 and 6 are placed symmetrically in the field of the constant magnet 1. The conductive cylinder 2 is arranged so that it intersects the part of the magnetic flux that closes along the first toroidal core 4 i.e., its end face is located in a plane passing between cores 4 and 6. As in the prototype, the source of a constant magnetic field 1 can be connected to a controlled shaft 3, then cores 4 and 6 with windings 5 and 7 will be located ozheny outside the cylinder 2. As a source of constant magnetic field 1 may be used permanent magnets or electromagnets. Cylinder 2 is made of any conductive, but non-magnetic, material. It is advisable to use windings 5 and 7 with the same number of turns from a wire of the same section, and cores 4 and 6 with the same basic magnetic characteristics. In order for the cores 4 and 6 not to be displaced one against the other during operation, it is constructive and desirable to carry them out into a single unit, fastening the cores 4 and 6 with the windings 5 and 7 in FIG. 1-3, not shown. The inclusion of the windings 5.7 made according to the scheme in figure 2 or 3, i.e. according to the differential transformer connection circuit.

The device works as follows.

With a non-rotating shaft 3, the device is adjusted, the cores 4 and 6 are installed with windings 5 and 7 relative to the source of a constant magnetic field.

1 so that the recording device 10 to fix the zero signal level. If there is no zero signal, then this is achieved by shifting the cores 4 and 6. When the zero signal is reached through both cores

0, magnetic fluxes of equal magnitude are closed, they are equally magnetized, and equal voltages are obtained on windings 5 and 7. When rotating the controlled shaft 3, and with it

5 and the conductive cylinder 2 in the latter induce eddy currents, which create their own magnetic flux directed oppositely to the magnetic flux of the source of a constant magnetic field 1 and reducing

0 the fraction of the magnetic flux, the magnetizing toroidal core 4. This increases the fraction of the magnetic flux, closing through the core 6. Thus, as the rotation speed increases

5, the conductive cylinder 2 redistributes the magnetic flux of the source of a constant magnetic field 1 that closes over the toroidal cores 4 and 6 — the fraction decreases, closes from core 4, and the fraction closes with core 6. This redistribution of magnetic flux leads to a decrease in the magnetic bias of the core 4 and an increase in the magnetic bias of the core 6, as a result of this, a change in the inductance of these windings and an increase in the steepness of the signal recorded at the output of the measuring unit 8 when changing the controlled speed of rotation that

0 provides increased sensitivity and range of controlled device speeds.

Claims (1)

The invention The device for controlling the speed of rotation, containing concentrically located source of a constant radial magnetic field and conductive cylinder associated with a controlled working body, the first 0 a toroidal core with the first winding placed on it, located in the gap of the magnetic circuit on the other side of the conductive cylinder relative to the source of a constant magnetic field, 5 a power transformer, a measuring unit, a registering device connected to the output of the measuring unit, so as to increase the sensitivity and the range of controlled speeds, A second toroidal core with a second winding placed on it and a third winding, the coils of which are placed on both toroidal cores, are additionally inserted into the magnetic core above the first toroidal core, the coils of which are placed on both toroidal cores along the height of the magnetic core gap. the first and second toroidal cores, and the first, second and third windings are connected in the measuring unit by a differential transformer connection circuit. ten Fig 3 7 6