Slow oscillations in systems with inertial vibration exciters

Abstract

The problem of the occurrence of semi-slow speed oscillations of an unbalanced rotor during its passage through the resonance zone has been solved using the method of direct separation of motions. It has been proved that when a stationary regime is established, semi-slow damping oscillations of the rotor speed arise in the region of the Sommerfeld effect, they are the result of the superimposement of free accompanying oscillations with a relatively low frequency on forced fast oscillations. In this respect, the initial amplitudes of such oscillations are quite large, and oscillations damping is relatively slow.

The dynamics of a resonance single-mass vibratory machine with a vibration exciter of targeted action that operates on the Sommerfeld effect

“…- [5] -for a pendulum rigidly mounted on the shaft of an induction electric motor installed on a platform that fluctuates horizontally.…”

“…The studies reported in [3][4][5] found that unbalanced masses (pendulums, wind wheels, etc.) get stuck at one of the resonant frequencies of platform oscillations.…”

Synthesizing a resonance anti-phase two-mass vibratory machine whose operation is based on the Sommerfeld effect

“…The easiest technique to excite resonant vibrations in vibratory machines is based on the Sommerfeld effect [7]. There are examples of this technique's application for singlemass [8], two-mass [9,10], and three-mass [11] vibratory machines. The effect is manifested in that the unbalanced rotor of a DC electric motor [9], or induction motor [8,10], the unbalanced impeller [11] cannot accelerate to the working frequency and gets stuck at one of the resonant frequencies of platform vibrations.…”

“…Vibratory machines can be single-and multi-mass. It should be noted that multi-mass vibratory machines possess a series of advantages over single-mass ones [3][4][5][6][7][8][9][10][11]. Thus, a multi-mass structure makes it possible to design vibratory machines that almost do not transmit vibrations to the foundation.…”

“…The most effective and simple ways to excite resonant oscillations are based on the use of the Sommerfeld effect [7][8][9][10][11][12]. Among these methods, there is a particular technique based on using passive auto-balancers in the form of vibration exciters [12,[17][18][19][20][21].…”