Mathematical models of sorting conveyors with belt and chain carriers

Source abstract

Relevance. This article addresses the problem of improving the reliability and accuracy of sorting timber conveyors with a chain load-bearing element equipped with a variable-frequency asynchronous electric drive. An increase in the length of the working section of an extended timber-sorting conveyor leads to a rise in the mass of moving parts, a stronger influence of the viscoelastic properties of the chain, and greater complexity of transient processes during start-up. As a result, dynamic jerks, wave-like tension fluctuations, and misalignment in the displacement of individual chain sections occur, which reduces equipment durability and impairs the precision of timber delivery to storage bins. The relevance of this study is determined by the need to maintain the design service life of the load-bearing chain (belt) as a key structural element. Aim. To investigate the motion dynamics of chain-type and belt-type sorting conveyors in order to establish the boundary conditions for the operation of the load-bearing section. Results and Conclusions. It has been established that the most hazardous operating mode is rapid conveyor start-up without mechanical vibration damping. The use of a fluid coupling reduces the initial tension peak and proves most effective during short start-ups (up to 10 s), as it smooths abrupt changes in the drive torque and diminishes the intensity of the initial tension wave. However, for extended conveyors, the action of a single fluid coupling is insufficient: in the region of the reflected wave at the end of the load-bearing chain, the systematic error in timber positioning may remain at an unacceptable level. The implementation of an S-shaped ramp function reduces the jerk at the initial start-up stage and, at the final stage, limits tension oscillations while maintaining acceptable sorting performance. To achieve the ultimate sorting accuracy on long conveyors, it is advisable to employ a closed-loop electric drive control system with displacement sensors for timber on the load-bearing chain and wireless data transmission; however, the implementation of such a solution would be technically complex and capital-intensive. The optimal outcome of applying a refined model of the mechanical part of an extended sorting conveyor to reduce excessive oscillations under the climatic conditions of Western and Central Siberia is achieved through coordinated control of the traction variable-speed electric drive in conjunction with an adjustable fluid coupling. For citation: Kladiev S.N., Sarbassova N.D., Umurzakova A.D., Odnokopylov G.I. Mathematical models of sorting conveyors with belt and chain carriers. Bulletin of the Tomsk Polytechnic University. Geo Assets Engineering, 2026, vol. 337, no. 8, pp. 153–167. http://doi.org/10.18799/24131830/2026/8/5753