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The paper deals with the study of Powered roof support analysis, taking into account the interaction with surrounding rocks. In this respect, an analytical model of kinematics and load of the shield, a differential model of the shield-rock system equivalent stiffness and a Fuzzy logic based analysis of the parameters variation are presented. In the first two models, the classical approach of shield mechanics, the loading scheme was modified by taking into account the horizontal force acting between the roof and th...

The scientific paper deals with the multi-criterion optimization of the teeth that are used on the buckets of bucket wheel excavators. From past theory and practice, it is known that geometry of the tooth greatly influences the cutting parameters and the endurance and the strength of the tooth itself. The dependencies between the cutting forces, the penetrating forces, the specific energy on the rake angle and the relation between this last one and the robustness of the tooth are somewhat contradictory, so in the ...

The scientific paper proposed deals with the reliability analysis of the average usage time of the brake pads as components of the braking system of the industrial front-end loader and transporter machinery used in mining operations in Romania. The research was conducted at the request of several mining companies in Romania, that are using the front-end loader and transporter machinery in their daily operations. The study is based on the empirical information and the preliminary reliability results that were recor...

The paper deals with the theoretical and practical analysis of the influence that the cutting direction of the bucket wheel excavator has on the digging forces acting on the wheel. Usually, when the terrace cut technology is applied, the bucket wheel of the excavator cuts vertical chips where mainly the perpendicular to stratification digging method is predominant. All the laboratory trials - done on the test rig - were conducted mainly for this type of vertical chip cutting. In cases when the drop cut method is a...

The specific energy consumption is mainly influenced by kinematics and dynamic measures of vertical transport installations as well as by the compatibility of different composing parts and their subcomponents. The optimisation of kinematics and dynamic parameters characterising a transport cycle is decisive considering the energy consumption. Also considering the operation of the vertical transport installations, as well as the character of the variation of kinematics and dynamic parameters during a race, it has b...