Podolyak O. Increasing technical and operational parameters of boom mobile cranes using hydraulic dampers

In this paper the scientific and technical problem of increasing the technical and operational parameters of boom mobile cranes installing hydraulic dampers in the skyhook system of load, in which the resistance varies according to the given law, is solved. The condition of boom mobile cranes park is considered and is found that some of the cranes, which have worked out their term of service an average are 75% of the total, and the main reason of they amortization are damages of elements, that appear in the issue of dynamic loads. Also is found that takes and spread the major part of dynamic loads by lift - down movement the load. The boom system consists of the drive mechanism for lifting, load skyhook and boom with boom block and tackle system. The research tool that includes dynamic, mathematical and physical models subject to the hydraulic dampers in the boom and load skyhooks, as well as their characteristics is developed. The regularities of functioning of dampers with elements of the lifting mechanism and crane metalware are obtained. A new engineering solution of damper and method of its basic parameters are suggested. The experimental setup is developed and the effectiveness of the proposed damper, as well as the goodness of fit of theoretical research are tested. The technical and economic assessment for the application of the developed damper is done and is found that the introduction of the proposed device makes it possible to reduce the mass of boom metalware at 27,5%, and increase the life of the crane in 1,4 times.