Modernization of the system for ensuring the stability of the railroad crane KZh-971 and evaluation of its effectiveness

The weight of the load hanging on the boom of a railroad hydraulic crane KZH-971 creates a load moment that bends the crane slewing ring. To partially balance the load moment, a stationary counterweight is installed on the crane, rigidly fixed on a slewing platform. With an increase in the boom departure, the unbalanced part of the load moment and tensions in the slewing ring increases. In this article, to ensure a constant value of the unbalanced part of the load moment and reduce bending tensions, it is proposed to install a counterweight on the railroad crane with a telescoping system and the ability to rotate about the vertical axis for a work in cramped conditions. A strength analysis of the slewing ring for the change in maximum tensions from the use of a movable counterweight was carried out. An adaptive control system for the position of a movable counterweight has been modeled, with the help of which it will be possible to develop a device for convenient control from the crane operator's cabin in the future. The advantages of using a movable counter-weight with the possibility of rotation relative the vertical axis are shown when performing loading and repair work in cramped conditions. The results of the strength analysis of the slewing ring with the location of loads in the main working positions are summarized.