Vibratory conveyors

• Main Author: Redford, Alan Harry
• Published: University of Salford 1966
• Subjects: 691; Construction equipment
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.484030

A review of the previous work on the mechanics of vibratory conveying is given., It is found that several theoretical studies have been made in the past but the predictions of the theories and the comparisons of these' with experimental results have only been applicable to a very limited range of the relevant variables. In the present work, a theoretical analysis is described which enables the mean conveying velocity of a component on a conventional vibratory conveyor to be determined for'a wide range of the relevant variables. Since an alternative method of vibration is discussed, "conventional" refers' to vibratory conveyors which are commercially available. The results of this theory are compared with the results of experimental work conducted on apparatus specially designed for the purpose. Within practical limits, good agreement is obtained. From this work it is concluded that fundamental limitations eXist in conventional vibratory conveying, the most important of which are that the conveying velocity is very sensitive to changes in the coefficient of friction between the component and the track and for low coefficients of friction, the conveying velocity for steady conveying is inadequate. • A further analysis is then described which considers the mechanics of Vibratory conveying where a phase difference exists between the normal and parallel motions of the track, (known as "out of phase" conveying). Again, within certain limits, the new theory is in good agreement with experimental results. It is apparent from this work that with the correct phase relationship between the two components of vibration, definite practical advantages exist over conventional conveying. With "out of phase" conveying, the component velocity is virtually independent of the nature of the component and track materials and conveying velocities significantly higher than those obtainable on a conventional vibratory conveyor axe possible. Further, with this vibration system, components can be conveyed separately and without erratic motion up an inclined track. A practical method of obtaining an "out of phase" vibration on the track of a vibratory bowl feeder is suggested. The results of performance tests on two commercially available vibratory bowl feeders with conventional drives are presented and it is shown that in both cases their performance is very sensitive to changes in the bowl load. A method for reducing this effect by re-tuning the bowl spring support system is demonstrated. Some suggestions for improving the performance of conventional bowl feeders are discussed which include details of how the track angle, vibration. angle, track material and suspension spring stiffness should be determined.