With a horizontal shaft It must be possible to lift the choked sprung mass of the screen at the end of the eccentric. That is your stalled condition. Sprung mass is subject to the suspension uplift. At the choked state the spring thrust will be greatest and at the empty condition it will be less. That torque value is independent of speed, stroke, weight distribution and all the rest of it.

After you have arrived at the torque requirement you will have to factor it according to speed: which is a more complex matter. But if you can't lift it, you can't shake it.

For a vertical shaft you probably need to consider the weight of the burden and its friction imposed on the screen deck. Again it starts off simple and then gets involved in dynamics which are not as complex as for a horizontal shaft but are there nevertheless. ■

Dear Sir,

I am executing linear screen design project for which i intent to use geared exciter. should i consider the weight of exciter during my calculations of location of exciter mass through CG? ■