Determining operation parameters of the leverage mechanism in a mining excavator

. The paper analyzes the process of rock excavation using a front-shovel operational equipment of an open-pit excavator in the context of determining rational modes of operation for its main mechanisms (lifting and thrusting mechanisms) during the excavation. The main purpose of the study is to establish the kinematic and dynamic characteristics of the excavation process by identifying patterns of changes in the operating parameters of the main mechanisms. Research methodology includes mathematical modelling and computational experiment with the use of machines and mechanisms theory methods. Results. Dependencies were obtained to determine rational values of lifting and thrusting velocities which ensure that the bucket (top of its cutting edge) moves along a specified trajectory while excavating. A simulation model was built for the process of rock excavation carried out by front-shovel excavators, which represents a set of calculated values for the operational parameters of the main mechanisms to realize the bucket movement along a specified path and provide specified energy-force parameters on the bucket. An optimizing algorithm was developed to control the working process of an open-pit excavator and achieve required values of the operation parameters to get the bucket moving at a specified excavating velocity within the work area of the excavator. It is shown that their joint action forms a kinematic chain which connects the main mechanisms and the bucket and includes driven links of those mechanisms and elements of the operational equipment. Operation parameters of the main mechanisms were found to be formed in accordance with kinematic properties of the transmission mechanism (with the kinematic chain as its part). Scope of results. The results of the research could be used to develop a control system for the drives of the main mechanisms.