Mathematical model of the safety clutch in the screw conveyor drive for loose raw materials

Abstract

Goal. To increase the operational characteristics of the screw conveyor when its working body is overloaded by substantiating the rational parame­ters of the safety clutch. Methods. Theoretical studies were carried out using the methods of theoretical mechanics and higher mathematics. Theoretical calculations of the obtained analytical dependencies and their graphical interpretation were performed on a PC using the Delphi software environment. Results. To increase the amount of axial movement of the driven half-coupling with a jammed working body, together with the reduction of dynamic loads during the occurrence of an overload, a design of a safety clutch has been deve­loped. To determine the rational parameters of the safety clutch of the screw conveyor, the influence of dynamic loadrived dependencies for determining the moment of interaction of half-couplings Tm. To implement the numerical solution of the mathematical model, a Pascal program was created in the Delphi visual programming environment, which makes it possible to build graphical dependencies and investigate the influence of various system parameters on dynamic loads in the drive links of the screw conveyor. The obtained mathematical model allows you to determine the influence of the main parameters on the dynamics of the operation of the safety clutch of the screw conveyor when the working body is overloaded. Conclusions. Based on the dynamic model of the screw conve­yor with a safety clutch, which is composed of the differential equations of motion of the system elements. According to the results of theoretical stu­dies, graphical dependences of the change in the torque value during rotation of the half-couplings of the safety clutch were constructed to study the influence of various system parameters on dynamic loads in the drive links of the screw conveyor. From the analysis of the graphs, it was established that an increase in the rotation frequency leads to an increase in the torque of the system. Thus, when the rotation frequency changes from 50 rev  min–1 to 200 rev  min–1, the torque Tn increases by 64.8%, Tr increases by 65.2%, and Tm increases by 63.8%. It was also established that an increase in the mass of moving parts leads to an increase in the load on the drive. When the mass increases from 10 kg to 20 kg, the torque Tn increases by 15.8%, Tr by 12.5%, Tm and by 17.3%. On the basis of the conducted dynamic analysis of the process of activation of the safety clutch of the screw conveyor, it was established that an increase in the rotation frequency of the working body leads to an increase in the torque of the system.