Nechytailo O. Assurance of strength of guide pulley resting units of frame sloping shaft headgears

The thesis is devoted to the development of a procedure of designing steels structures of frame sloping shaft headgears, in particular to sub-pulley structures under a complex stressed state. The thesis offers a description of the object of research and an a priori analysis of the sources being related to the design of shaft headgears, with the dynamics of hoisting rope loads being taken into account. A mathematical model of the mode of deformation of sub-pulley structures was developed, with the dynamic interaction of guide pulleys and hoisting ropes being taken as a single mechanical system. The laws of extreme local normal and reduced stresses initiation in guide pulley resting units were determined. There are given the results of full-scale experiments when the character of distribution of local stresses in guide pulley resting units of frame sloping shaft headgears and the characteristics of the cycles of dynamic stresses in the design points of sub-pulley structures. The significant factors affecting the mode of deformation of guide pulley resting units and regression dependences of extreme local normal and reduced stresses on the most significant factors were determined. An engineering procedure of designing guide pulley resting units by the strength criteria in the range of contact stresses under a support bearing was developed and recommen-dations on intelligent design of guide pulley resting units are provided.