Abstract :
In the process of performing a technological operation on the working body of the road mill sharply variable random loads occur. This is due to the periodic nature of the interaction of the cutting elements with the material being processed and the random nature of the change in the milling depth, the physical and mechanical properties of the medium being processed, as well as the operating modes. The article proposes a model of formation of the moment of resistance on the mill during interaction with the processed material. The case when the working body consists of several sections, each of which has several cutting planes, with a different number of knives in the plane, is considered. Factors that determine the nature of the load, such as the frequency of interaction of the cutting elements with the processed material and the randomness of the operating conditions of the unit, lead to their presentation as a sequence of pulses with random parameters. Expressions are obtained in the article that allow calculating the mathematical expectation and spectral density of the moment on the working body at the design stage, taking into account the operating modes, its design, the physico-mechanical properties of the milled material and their probabilistic characteristics. The probabilistic characteristics of the loads on the mill serve as initial information for the dynamic analysis of the drive system and the design of the unit, its strength analysis, and the selection of optimal parameters and operating modes.
Keyword :
road mill, milling drum, model of moment of resistance, mathematical expectation of moment, spectral density of moment.