Mathematical Model of the Influence of the Gathering-Stars Loading Organ's Parameters on the Choice of the Tunnelling Machine Conveyor Speed

Modern roadheaders of selective action are mostly equipped with loading organs with gathering stars, which have simpler drive structure and increased reliability. On the one hand, process of traffic flow forming by loading organs with gathering paws is well studied, and on the other hand, the variety of its designs suggest of the manufacturers' attempts to find empirically optimal parameters of loading organs of road headers. As a result, the manufacturers of tunnelling combines determined that, with some combination of structural and kinematic parameters, the probability of falling a lump of material between the side of the receiving conveyor and the gathering-star beam and jamming it is high. Ways to solve this problem are: increasing the interaxial distance of the gathering-stars, reducing the boom of the gathering-star beams over the receiving conveyor, changing the shape of the beams, applied separately or together. As a result of experimental and theoretical studies performed at SRSPU(NPI), Russia a mathematical model of the process of interaction between the gathering-star beams and loading material was developed. The paper considers geometric and forces parameters that affect the possibility of wedging a gathering-star beam with a lump of material, taking into account certain limitations. A condition is established which makes it unlikely that the gathering-star is jammed, and has allowed the development of methodical approaches to the design of loading organs with gathering-stars with specified quality characteristics.