Increasing the resource of a friction pair knife-grid in screw grinders of solid materials

This article discusses one of the urgent problems of optimizing the design parameters of screw grinding and cutting machines, which consists in reducing the wear rate of knife blades due to the transition from the traditional mounting scheme for a pair of knife-grid in the cutting head along the outer annular perimeter, to a progressive mounting scheme along the circumference of the central lattice holes.. In the study, the problem of estimating the wear rate of the blades of a screw grinder knife under various conditions of fastening of the cutting knife-grid pair was posed and solved by analytical methods, and the duration of the running-in period of the friction pair was determined with the traditional fastening scheme, leading to the concentration of contact stresses. Based on the analysis of the features of the physical model of the process of contact interaction between the blades of the knife and the grid, the conditions for fixing are formulated, which exclude the concentration of mutual friction forces in the knife-grid junction and ensure a decrease in the wear rate. At the same time, it is shown that the implementation of the proposed method makes it possible to double the resource of the cutting head and eliminate the phase of intense running-in wear of the knife blades, which causes a decrease in the quality of grinding.