Part dynamics in the intermediate regime of a linear vibratory feeder

Linear vibratory feeder is one of the most extensively used part feeding systems in a production line. The part motion on the feeder can be sliding or hopping or a combination of these two. Based on the dynamics of part motion this paper identifies three distinct regimes. A mathematical model was developed that can predict the trend in conveying velocity in these regimes. This model can provide the parts position as a function of time and has considered relative displacement between the part and the conveying surface. The simulation was validated by performing experiments for a range of vibration frequencies and amplitudes.

Dynamics of part motion on a linear vibratory feeder

The motion of a part on a curved surface mounted upon a linear vibratory feeder is of great importance in mass production. In this article, the conveying surface or track is modelled by a bilinear surface inclined to all axes with the curvature varying throughout the surface. An experimental test rig is fabricated to study the part motion on the feeder surface. Dynamics of the part on the surface is derived and the path traced by the part is obtained numerically. The numeric model closely correlates with experimental results. Based on the control parameters two distinct regimes—slide and hop—are presented, highlighting their relation to frequency and amplitude of vibration of the feeder.

DYNAMICS OF HEAVY VIBRATING MACHINES TAKING INTO ACCOUNT INSTABILITY IN TIME OF THEIR PARAMETERS

Underground mining of uranium ores consists of several technological processes, one of the most important of which is the release of broken rock from the working excavation zone and loading it into transportation vehicles. The issue of increasing the intensity of production requires a simultaneous increase in the productivity of all production processes, including the production of mineral raw materials. At the same time, it is necessary to create both a high-performance and a safe process. This problem is successfully solved by the use of vibration machines with elastic links made of elastomeric materials, which, along with an increase in productivity, can reduce energy consumption and the number of freezes. An integrated approach was used, which includes analytical studies and results of industrial tests of vibratory feeders for underground mining and delivery of uranium ores and building materials. On the basis of the developed algorithm and synergistic model of fatigue microfracture of rubber links in vibratory feeder, mathematical equations were obtained, which made it possible to describe dynamics of feeders with time-depending parameters; when solving the integro-differential equation of the oscillatory system, the dependence of the amplitude characteristics of the feeder on the time of its operation is obtained. An original algorithm and synergistic model were developed, and on their basis, a mathematical apparatus was created, which allowed determining change of amplitude of vibratory feeder oscillations during its operation. On the basis of analytical calculations, a method was developed and introduced for predicting changes of parameters change of oscillation amplitudes of vibratory feeder used for underground mining and feeding of uranium ores.

Improving the performance of vibration feeders with an electromagnetic vibration drive and a combined vibration system

Vibration loading devices are widely used in various branches of mechanical engineering to load piece blanks of automatic machines and automatic lines as well as robotic systems, automated systems and flexible automated production. Vibration devices for transportation and loading of miniature, small and medium-sized products are the most widely used. Modern designs of vibratory feeders, made according to the classical dynamic scheme and having a two-mass oscillating system, do not fully use the energy of the vibratory exciter to perform useful work. In addition, due to the presence of a heavy reactive mass, they have a fairly large weight. When the vibrating feeder is operating, the energy of the vibration exciter is spent on pumping both the hopper, which performs useful work, and the reactive plate, which performs idle vibrations. Thus, part of the energy of the vibration exciter is not used for performing useful work, but is spent idly. To increase the efficiency of the device, increase its performance and reduce its weight and metal consumption, it is necessary to change the design of the vibratory feeder and some of its elements, which affect the redistribution of the oscillation amplitudes of the working (hopper) and reactive mass of the vibratory feeder. Modern production involves the creation of new models of machines with high technical and economic indicators, therefore, improving the efficiency of existing equipment and the development of new schemes of machines is an important task for designers and manufacturers of technological equipment, as the minimum improvement of its technological and operational performance can lead to a tangible economic effect. To solve this problem we developed a new design vibrating hopper feeder, in which the increase of the horizontal component of the oscillation amplitude of the working element (hopper) is not at the expense of increased power of the vibratory exciter, but due to internal redistribution of energy between the elements of the oscillating system that makes better use of the energy of the vibratory exciter to perform useful work, i.e. to increase the coefficient of useful action. In addition, the weight and metal content of the vibrating feeder structure are simultaneously reduced.

Performance and noise analysis of vibratory feeder using dynamic rubber spring model

In vibratory feeder, material feeding occurs due to the vibration of a trough mounted on helical springs. High vibration amplitude of trough causes the springs to jump and usually results in higher noise level generation and increase in force transmissibility in the support structure of the feeder. Reducing this noise without having significant changes in the dynamics of the feeder unit is a major challenge in the present industries. This paper presents a dynamic rubber spring model for vibratory feeders to reduce the noise level and the force transferred to the support structure of the feeder. Measurement of dynamic parameters such as vibration amplitude and magnitude of force transmitted to support structure, noise level, and conveying speed of particle analyses have been conducted experimentally on vibratory feeder with and without rubber gasket installed at spring support structure. The use of rubber gaskets at spring supports and their implication on force transmissibility and noise level of feeder is established experimentally. The performance analysis of feeder was also conducted using particle conveying speed on trough for different setups of feeder unit. It was found that the introduction of rubber gaskets at spring supports of the feeder increases the system damping, which helps in noise reduction as well as reduced amplitude of vibration and higher acceleration of trough. The increased acceleration leads to higher particle conveying velocity on the feeder trough.