Prospects of Use of Vibratory Devices with Electromagnetic Drives for Massive Piece Goods Conveying

Vibratory conveying devices with electromagnetic drive are widely used in the different branches of industry. As a rule, they deal with relatively small piece goods and are not suitable for conveying of the large massive goods with high productivity. The conveying of massive piece goods needs the using of non-hopping modes of moving in which the high velocity can be reached only in the case of non-linear vibration trajectories of the conveying track, for example elliptical trajectories. Such trajectories are obtained by using of the independent drives of horizontal and vertical oscillations. Even greater velocity can be reached by using biharmonic vertical oscillation with particular optimal relations between amplitudes and phase differences of the component oscillations. These types of devices can be designed on a basis of three-mass oscillating system. Theoretical and experimental investigations show that the goods' mass change significantly affects the vertical oscillations and weakly affects the horizontal oscillations. And at the certain relations between masses ratio and resonant tuning (ratio of frequencies of forced and natural oscillations) the vertical oscillations of active mass of two-mass vibratory device are insensitive to the change of goods' mass. The sensitivity of vibratory conveying stability to the goods' mass change was investigated for two-mass vibratory devices with elliptical oscillations. Three-mass oscillating systems with biharmonic oscillations in the point of view of the sensitivity to the goods' mass changing were not considered. Analysis of different three-mass oscillating systems with electromagnetic drives of harmonic horizontal and biharmonic vertical oscillations allows determining two most preferable versions. The equations for amplitudes of components and frequencies of natural oscillations determining are derived. From the condition of insensitivity to conveying mass change the optimal relations between masses ratio and resonant tuning are obtained.