Abstract: Objective. The results of a theoretical study of the load change in the developed chain drive with uneven rise and fall of dried raw cotton by longitudinal shelves inside the 2SB-10 drum during the drying process. Methods. In the process of research, the principles of higher mathematics and theoretical mechanics, special and modern methods of measurement, evaluation, comparison, methods of mathematical statistics and computational mathematics, computer software were used to assess the differential equations. Results. Differential equations are derived for determining the torque, the required power of the electric motor and for choosing the brand of the chain. Conclusion. Based on a theoretical study, it can be concluded that the calculated design scheme of a drum dryer with a chain drive made it possible to derive differential equations for determining the torque, the required power of the electric motor and for choosing the chain brand.