SU1425498A1 - Vacuum gauge - Google Patents

Abstract

The invention relates to vacuum technology and allows for improved accuracy in the registration of fast processes. The housing 1 contains a rotor 2 in the form of a hollow cylinder with blades 3 “. At the bottom of the rotor 2 there is a radially symmetric cavity 9 filled with an electrically conductive liquid and closed with a dielectric cover installed west-face with the rotor end 2. Coaxially to the rotor 2 with a gap relative to An annular permanent magnet 8 is installed at its bottom. The radial oscillations of the rotor 2 induce the movement of an electrically conductive fluid in cavity 9 due to magnetohydrodynamic effects causing damping of extrinsic oscillations. 2. The rotor 1 yl.

Description

AI

WITH

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 The invention relates to vacuum

technology and is intended to be accurate; measuring pressure in the range of Hg.

The purpose of the invention is to improve the accuracy of the pressure measurement during the registration of fast processes. The drawing shows a vacuum gauge. The vacuum gauge contains a housing 1,. One: three of which is a rotor 2, made in the form of a hollow cylinder with blades 3, mounted on an axis 4, suspended in magnetic angular contact bearings 5 and 6 on permanent magnets, and an inductor 7 electromagnetic promotion . The hollow cylinder is made of an electrically conductive non-magnetic material, such as copper. An annular permanent magnet 8 is mounted motionless inside the housing 1 coaxially with the rotor 2 with a gap of 5 mm relative to its end part, which is I level with the blades I 3. At the bottom of the cylindrical rotor I -symmetric- I on cavity 9, filled with electrically-I conductive liquid, for example, with mercury I The vacuum meter works as follows I,

: The cylindrical rotor 2 is unwound-: by the electromagnetic field of the inductor 7 through the dielectric part of the core; 1. When a certain rotational speed, which is measured with a sensor (not shown), is reached, the spinning is stopped and the rotor 2 is braked blades 3 on the residual gas. By reducing the speed of rotation of the rotor 2 by an amount determined by the resolution of the sensor and the required measurement accuracy, the deceleration time is fixed. The duration of the measurement cycle determines the pressure in the vacuum system.

When a disturbing force is applied to the rotor 2 in the radial direction, impulse radial oscillations of the rotor 2 appear. The cilin, drike rotor 2 is provided with a radially symmetric cavity 9 filled with an electrically conducting fluid, such as mercury. Therefore, the radial oscillations of the rotor 2 cause the electrically conducting

due to the magnetohydrodynamic effects, which leads to the flow of liquid within the radially, symmetrically symmetric cavity 9. The oscillation energy of the rotor 2 transforms into the kinetic energy of the flow of electrically conductive liquid and B thermal energy due to eddy current effects. The kinetic energy of the flow of an electrically conductive fluid is also converted into heat due to both the internal friction of the layers of the liquid itself and friction against the walls of the cavity 9.

Thus, damping of the induced oscillations of the rotor 2 occurs due to energy dissipation not only due to eddy-current effects, but also due to magnetohydrodynamic effects. Moreover, the damping of forced oscillations of the rotor 2 due to magnetohydrodynamic effects is 3-5 times higher than the damping of oscillations due to eddy current effects.

The application of the invention allows to increase the accuracy of pressure measurement by 30-35% and increase the speed of the vacuum gauge by 4-6 times by reducing the readiness time of the vacuum gauge due to a significant decrease in the amplitude of the forced radial oscillations of the rotor.

Claims (1)

Invention Formula A vacuum gauge, comprising a housing and a rotor, which is made in the form of a hollow cylinder with blades and mounted on an axis suspended in magnetic radial-thrust bearings, an inductor of electromagnetic unwinding, an angular velocity sensor and a fixed ring magnet fixed inside the housing coaxially to the rotor a gap with respect to its end part, characterized in that, in order to increase accuracy when registering fast processes, a radially symmetric radial-like pattern is made in it in the cylindrical rotor from the side of the ring magnet. a metric cavity filled with an electrically conductive fluid, with the cavity closed by a dielectric fastener flush with the end of the rotor. VNIIPI Order 4759/38 Random polygons pr-tivg G. Uzhgorod, st. Project, 4 Circulation 847 Subscription