Calculation Analysis Of Mast Erection Mechanism Of Crawler Crane

As important lifting equipment, crawler crane has played an irreplaceable role in the application of large-tonnage, large-radius lifting field. Mast, as an important component of crawler crane, is significant to self-assembly as well as boom lifting. In the process of erection, the main resistance comes from gravity and the pull of luffing rope. In engneering design, the accuracy of results is affected by simple superimposed calculation because of the coupling of both. The mast cannot be normally erected for underestimation of loads.On the basis of fully consideration of the rope stiff losses and catenary theory, a calculation method is proposed for the critical angle of mast free-fall and the reaction force of mast erection mechanism, which is validated through experiment verification.Based on the engineering project of QUY750carwler crane, this project mainly includes:(1) Based on introduction of composition of the crawler crane and luffing mechanism, the mast lifting device working principle and functions is studied.(2) Catenary theory is used to study the influence of wire rope weight onto the rope tension; meanwhile, given the effect of the rope tension onto stiff losses, a calculation method is proposed to calculate pulley block efficiency and tension of wire rope, which is suitable for the small loads cases.(3) According to analysis of forces of mast erection device in the erecting process, a method is proposed to calculate the mast free-fall critical angle and reaction forces of erection mechanism in the erecting process. An example is applied to verify feasibility of the critical angle calculating method proposed.(4) Effect is studied on reaction force caused by factors such as luffing rope pull, stiff losses, and so on. A rule is presented for winch to loosen rope in the erecting process.(5) According to comparison of calculation results with experimental data, the calculating method is proposed by this paper is valiated.