The primary processing represents an important link of the process of capitalization of vegetal-origin products and, at the same time, an essential operation of the conditioning chain. Taking into account all considerations, the experts׳ attention has been drawn by the study of phenomena which influence upon the impurities separation process, aiming at a maximum reduction impurities. The paper presents the constructive-functional scheme of an gravitational separator SP-0 0 design, manufactured and testing at INMA Bucharest and the movement Eq. of gravitational separator centrifugally driven by means of non-balanced eccentric masses and also the constructive scheme of electric motovibrator, in view of its utilisation with best results for the drive of vibrating sieves of technical equipments used for impurities separation out of cereal seeds.