Litter index

The throw index Γ is a dimensionless quantity for vibratory conveyors , such as B. Vibratory bowl feeders . It indicates how strongly an object is vertically accelerated to the maximum relative to the gravitational acceleration g of the earth. Conveying speed , throwing height and thus the average conveying capacity depend on the throwing index.

The throw code can be in sinus calculate shaped waveform according to the following formula:

${\displaystyle \Gamma ={\frac {4\pi ^{2}f^{2}r\sin(\beta )}{g}}}$

The following quantities must be known for the calculation:

f = frequency of the oscillation of the spring-mass system (is usually determined by the drive and thus by the coil)

r = amplitude , half the stroke of the springs that connect the drive (coil) and conveyor trough

β = angle of attack from the horizontal (direction of oscillation)

g = gravitational acceleration

If Γ ≤ 1, there is pure shaking operation without throwing motion, since the resulting vertical acceleration is smaller than the acceleration due to gravity. For a throwing movement (micro throw) and the associated conveying, Γ> 1 must be. Litter numbers between 1 and 3 are common.

Machine code

The ratio of the maximum total acceleration to the acceleration due to gravity is referred to as the machine code  K and is a measure of the mechanical stress on the vibrating channel. In the case of sinusoidal oscillation, the following applies:

${\displaystyle K={\frac {\Gamma }{\sin(\beta )}}={\frac {4\pi ^{2}f^{2}r}{g}}}$

literature

• Matthias Coppers, Rolf Körber, Paul Schmidt: Sieben und Siebmaschinen - Basics and application, WILEY-VCH Verlag GmbH (2003), ISBN 3-527-30207-7 (Chapter 3.1.2 Throwing sieves)
• Karl-Heinrich Grote, Jörg Feldhusen (Hrsg.): Dubbel - Taschenbuch für den Maschinenbau, 22nd edition, Springer 2007, ISBN 978-3-540-49714-1 (chapter conveyor technology - continuous conveyors)