The WSP vibrating screens are very robust pre-screening equipment, usually used in primary crushing units, between the feeding machine and the crushing machine. Particularly suitable for processing alluvial materials, they mainly consist of a deck-holding frame suspended on helical springs, a top deck built with anti-wear steel bars, a central shaft protection guard, a mesh tension system, grease lubricated bearings, adjustable eccentric masses for the variation of the flow rate. WSP screens have an the eccentric shaft which is connected to the main frame by means of two bearings and supports, generating constant and continuous oscillations, driven by electric motor through pulleys and belts.