. Screw conveyors are widely used in the movement of various loose and lump materials related to agricultural production, such as: seed granular materials, cereals, bran, chaff, turf, flakes, mixed feed, mineral fertiliser pellets, etc. However, the conventional flexible screw conveyor operating mechanisms do not fully meet the operational requirements for these types of conveyors. Screw operating mechanisms are characterised by the complexity of the design and manufacturing technology, high material consumption, which causes increased energy consumption, damage to the transported material and the inner surface of flexible sleeves. Therefore, the task of developing new designs of flexible sectional screw operating mechanisms with advanced technological capabilities is urgent. To increase the reliability of the flexible screw conveyor, it was proposed to make its operating mechanism from separate screw sections that are pivotally connected to each other. Therefore, the purpose of this study is to determine the rational parameters and operating modes of the developed operating mechanism, which would ensure stable transportation of loose and lump materials on various technological routes. The study was conducted using the methods of differential and integral calculus, the theory of mathematical and computer modelling, mathematical planning of the experiment. This paper shows the results of theoretical and experimental studies of the process of transporting loose or lump material in the inactive zone between the pivotally connected screw sections of a flexible screw conveyor. The results of comparison of the obtained results of theoretical and experimental studies are shown. This allows choosing rational design, kinematic and technological parameters of the developed sectional screw operating mechanism when moving loose or lump agricultural materials along curved routes, both in horizontal and inclined directions, and along curved routes