Skewing of crane during acceleration

Abstract

During the work of crane and during its driving on the crane track, the so-called skewing of the crane arises. The physical phenomenon of crane skewing has been interpreted in various ways in the past. This corresponded to various physical models of skewing, which were created by various authors and which were presented in the standards for the design of crane structures and tracks. Current standards define the skewing as the so-called oblique running of the crane along the track with uniform movement. This is a situation where the force on the front guide means returns the obliqued crane when driving to the straight position. Theoretical formulas for the calculation of forces caused by skewing during oblique running crane were determined by Hannover. These relationships apply to movement of the crane with constant velocity along the crane track. The author of the article derived a model of a crane, which allows to investigate the movement of the crane along the crane track in general, it means both during uniform movement and during its acceleration or deceleration. It is a dynamic model that allows the solution of equations of motion to solve the coordinates corresponding to the degree of freedom and, among other things, to determine the forces between the crane and the crane track. This article presents the results obtained from this model for a specific selected crane during its acceleration. The contact of the front guide wheel is assumed, which is in accordance with the model derived by Hannover and which is also stated in the currently valid standards.