Parametric models of resistance to movement of a cargo truck of an overhead crane

The factors of resistance to the movement of the bridge trolley as a system consisting of many elements that are in structural and functional relationships with each other and change little during the operation of the system are considered and their parametric models are compiled. At the same time, the interdependent influence of structural, technological and operational factors in the system is considered taking into account their manifestation in various physical effects. A multi-level hierarchical structural-functional-parametric model of the system has been compiled, formed on the principle of a sequential two-level hierarchy, as well as parametric models of various levels applied to the periods of the most intense change in the states and transformation of the system in the process of functioning: resistance from rolling friction; resistance from friction in the axle boxes; resistance from the current supply; resistance from slope; resistance from inertia. A constructive method of reducing the resistance to the movement of the crane is considered by introducing elements of elastic suspension of the crane bridge into the design, which ensures the formation of a negative slope, characterized as a «kinematic slope», the value of which varies in proportion to the change in the position of the cargo trolley. The concept of parametric reliability is defined, applied to the drag system of the bridge crane trolley, as a time function characterizing the probability of fulfilling the condition of finding its numerical values in the limits set by the technical conditions.