Ukrainian Journal of Mechanical Engineering and Materials Science
Permanent URI for this communityhttps://ena.lpnu.ua/handle/ntb/31565
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Item Two-mass vibratory conveyor-manipulator with three-component electromagnetic drive(Publishing House of Lviv Polytechnic National University, 2016) Vrublevskyi, ІgorVibratory conveyor with three-component oscillations provides the opportunity to move the piece goods and details for any trajectory on a plane. Phase difference between independent horizontal (longitudinal or transverse) and vertical (normal) oscillations releases elliptical vibration of conveyor in plane perpendicular to the conveyor’s track. Elliptical vibrations allow increasing conveying velocity and inclination angle of conveyor’s track in comparison with the simplest linear vibrations. Three-component oscillations of the conveyor’s track are implemented by independent exciters of oscillations in the direction of conveying (longitudinal oscillations), oscillations in the direction perpendicular to conveying in plane (transverse oscillations) and oscillations in the direction perpendicular to conveying plane (normal oscillations) with phase difference between them. Conveying velocity of details moving upon the track varies with the change of phase difference angle and reaches a maximum with a certain angle, depending on several parameters. When electromagnetic exciters of longitudinal and normal oscillations are turned on, conveying details move in longitudinal direction. When electromagnetic exciters of transverse and normal oscillations are turned on, conveying details move in transverse direction. When electromagnetic exciters of longitudinal and transverse oscillations are turned on, conveying details rotate around their axes. When all three exciters are turned on, conveying details move at any trajectory. The change in the ratio of longitudinal and transverse amplitudes and phase difference angles between them allows changing the trajectory of details moving on conveyor’s track, making them not only move forward but rotate as well. That’s why such conveyor can be called a manipulator. The resilient system of two-mass vibratory conveyor-manipulator with three-component oscillations should have elastic pliability in three mutually perpendicular directions. It includes four resilient elements; each of them consists of two latticed leaf springs, fixed at the right angle to each other. The working body with conveying track is joined with reactive frame by resilient elements. Electromagnetic drive includes four electromagnetic exciters of longitudinal oscillations, four electromagnetic exciters of transverse oscillations and one electromagnetic exciter of normal oscillations. The bodies of electromagnets are fixed on the reactive frame and their anchors are fixed on the working body of conveyor-manipulator. A block diagram of the electrical control of conveyor-manipulator is referred. A voltage is supplied from two phases of threephase electricity to the coils of electromagnets through diodes, auto-transformers, switches and phase-shifter. The amplitudes of oscillations are regulated with aid of auto-transformers, phase difference between them and the change of conveying modes are carried by switches and phase-shifter. The oscillating system of vibratory conveyor-manipulator has six degrees of freedom and respectively six frequencies of natural oscillation. The formulas for calculating the vibratory conveyor-manipulator’s frequencies of natural oscillation are derived. Vibratory conveyor-manipulator with three-component electromagnetic drive was designed and manufactured. Its research and testing show the possibility of conveying details and piece goods at any trajectory.Item The phase difference between components of elliptical oscillations of vibratory conveyor providing maximum conveying velocity(Publishing House of Lviv Polytechnic National University, 2015) Vrublevskyi, ІgorThe piece goods conveying by the vibratory conveyor with elliptical oscillations is considered. Elliptical oscillations of the conveyor track are realized when conveyor has independent drives of oscillations in the direction of conveying (longitudinal oscillations) and oscillations in the direction perpendicular to conveying plane (normal oscillations) with phase difference between them. Elliptical oscillations allow increasing conveying velocity and inclination angle of conveyor track in comparison with the simplest linear oscillations. Conveying velocity of parts moving along the track of conveyor varies with the change of phase difference angle and reaches a maximum with a certain angle, depending on several different parameters. This angle is called the optimal phase difference angle, and it depends on the amplitudes and frequency of the component oscillations, the track inclination angle, the frictional properties, impact parameters of conveying parts. As the experimental investigations have shown, the piece goods conveying is quite accurately described by the theory of a massive point particle moving on an inclined plane under the action of vibration. A system of nonlinear differential equations describing the conveying in continuous contact modes and in modes with hopping was composed. This system has been solved by gradual integration method with numerical calculation with any desired accuracy. This allowed us to study the dependence of conveying velocity on different parameters in the form of graphs. And for greater generality the study was conducted in dimensionless parameters. There were studied in detail the influence of dimensionless parameters on dimensionless velocity – the coefficient of velocity that is the ratio of conveying velocity to amplitude of longitudinal oscillations with a constant frequency. To verify the obtained dependences, the experimental investigations of conveying velocity were carried out on vibratory conveyor with removable tracks. The conveyor was fastened on the turntable, the inclination of which was varied by a screw jack. The amplitude of the component oscillations was varied by changing voltage applied to the electromagnetic drives, the phase difference between component oscillations was varied by the phase shifter. Waveforms of oscillations were recorded by vibration measurement equipment. The coefficient of friction was measured directly during conveying. The velocity was measured by the stopwatch. The comparison of experimental results with theoretical data has shown the excellent agreement in continuous contact modes and the acceptable match in modes with hopping. Based on the obtained graphs, the approximate formulas for calculating velocity and optimal phase difference angle were derived. The influence of frictional properties of the conveying parts, namely, the coefficient of friction on optimal in terms of velocity phase difference angle between the longitudinal and normal components of the elliptical oscillations is investigated. It is shown that the optimal phase difference angle decreases with the increase in the coefficient of friction. The approximate formula of optimal phase difference angle dependence on the coefficient of friction and track inclination angle is derived.