SU104427A1 - Shake table - Google Patents

Description

As you know, during the operation of machines, for example in transport, vibration occurs.

A variety of devices, including electrovacuum, designed to work on machines where there is vibration, or near them, must have vibration resistance. Therefore, in the process of manufacturing devices, they often require their vibrating testing. For this purpose, vibrosteids are used, i.e. devices whose function is to create vibrations with different frequency and amplitude, which, in turn, determine the vibrational acceleration.

Vibrators are also used for calibrating instruments that measure vibration parameters (frequency, amplitude, acceleration). For this purpose, suitable stand-on shrouds that create almost pure sinusoidal oscillations, i.e., those whose distortion coefficient is of the order of 1% or less.

There are various designs of vibrostands: electrodynamic, based on the interaction of a magnetic field and a conductor, through

which is an electric current; electromagnetic, based on the interaction of ferromagnetic bodies, through which alternating magnetic flux generated by a solenoid flows; mechanical, based on the kinematic transformation of the rotational motion into reciprocating, and others.

Existing shakers create accelerations within 100 "d

.one/

19.81

In modern machines, vibratory accelerations, measured by hundreds of cells, take place, and the well-known stands do not create such large ycKopenHii and thus provide the possibilities of direct and direct measurement of the corresponding vibration meters or testing of some devices.

The present invention of pacmiipHet the range of vibration accelerations created in laboratory conditions, from 100 ”to a few thousand”, opens up new possibilities in the technique of vibration testing. In this case, the distortion coefficient of the shape of the curve oscillations: and -; ; It is at the level of the best of modern shakers.

The subject of the invention is a resonant shaker.

A distinctive feature of it is the use of the principle of self-excitation of the mechanical-electrical system using the mechanical oscillatory system of the fork.

The invention is illustrated in the drawing, which is a schematic diagram of a resonant shaker.

The oscillations are excited by an elec tromagnet 1, powered by alternating current from an electronic amplifier 2.

The principle of self-excitation is implemented as follows: the amplifier supplying the electromagnet receives a driver signal from the sensor 3, which is an inductive converter of mechanical oscillations into electrical ones.

The sensor 3 converts the vibrations of the mechanical system 4, which is a permanent magnet of the type of kwerts (core, into electrical oscillations).

The mechanical oscillatory system 4 has its own mechanical resonant frequency.

Self-excitation of the mechanoelectric system occurs at a frequency equal to the natural resonant frequency of the mechanical system 4.

Obtaining a large amplitude of mechanical oscillations and thus a large vibration acceleration is explained by

a) an exact coincidence in frequency and phase of the oscillatory force developed by the electromagnet 1 with the natural oscillations of the mechanical system 4;

b) fixing the mechanical oscillatory system 4 in the form of a tuning fork in its neutral point, lying on the axis of symmetry aa.

At the neutral point, there are no vibrations, which prevents the transmission of vibrations to elements lying outside the oscillatory system. The latter means preventing the suction of vibrational energy from an oscillating system 4.

The existence of a neutral point is explained by the symmetry of oscillations (in antiphase) of the shoulders of the Mexaiiji system 4.

Prev Invention Vibrostable, working on the principle of electromechanical; self-exciting system, which is also distinguished by the fact that, in order to increase the amplitude of vibration, its oscillatory system is made in the form of a karaton excited at a frequency close to the resonant one.