SUBSTANTIATION OF RATIONAL DESIGN PARAMETERS OF A CRUSHER WITH TWO MOVABLE JAWS.

Purpose. Design engineering of the mechanism of a two-jaw crusher with a compound motion of the jaws, which ensures a change in the angle of gripping of pieces of material within a very small range. Methodology. In the work, a theoretical study on the fourth-class lever mechanism, as the basis of a two-jaw crusher, was performed using the Mathcad 15 software. The study was performed on a vector representation of the links of the hinged mechanism. The development and analysis of constructive solutions were performed using the Autocad software product, which reduces the risk of errors and increases the quality of the design process. Findings. The paper theoretically determines the rational geometric parameters of the two-jaw crusher with the optimal value of the nip angle, whose crushing chamber is formed by the closed loop circuit of the flat fourth-class lever mechanism and proposes a new constructive solution of the mechanism for adjusting the crusher opening with two movable jaws and the bottom mounting of eccentric nodes. The developed device in the form of separate blocks is made with the possibility of their simple assembly and disassembly, which ensures the rate and quality of replacing lining plates or surfacing restoration of the worn working surface of the jaws. The relative movement of the jaws ensures the crushing of pieces of material with the required crushing coefficient. The geometric parameters were obtained by the method of kinematic synthesis. The geometric parameters of the crushing chamber of the two-jaw crusher were determined theoretically; the dependence was obtained of the change in the nip angle on the height of the movable jaw over a period of movement and the change in the compression stroke, which ensures the force interaction of the working surface of the jaws with the material. Originality. It is proved that the quadrilateral closed circuit of the fourth-class lever mechanism can be used as a crushing chamber of a two-jaw crusher. Two links of a closed circuit operate as jaws which break pieces of material. At the same time, the nip angle can vary within fairly narrow limits, ensuring the optimality of the crushing process. It was established that the considered option of the fourth-class six-link mechanism geometry has only two folds. An algorithm is presented for searching for assemblies with the purpose of identifying those that are closely adjacent. Practical value. The results of the conducted research provide the theoretical background and the algorithm for determining the optimal parameters of a two-jaw crusher which can be used at the stage of designing similar crushers. The developed design solution for adjusting the crusher opening expands the scope of application of double-jaw crushers. The obtained dependences of the change in the angle of inclination and the working surface of the jaw over a period make it possible to develop a rational mode of crushing the material. [ABSTRACT FROM AUTHOR]