ABSTRACT
One of the most important components of a dragline excavator is a boom. The weight of the boom has a significant impact on the weight of the entire machine, despite the fact that its weight is only 4.5-6.5% of the weight of the entire machine. High weight of the boom increases the weights of the mast, A-frame, revolving frame, etc. All this leads to increased specific ground pressure, which in turn leads to the need to increase the supporting surfaces of the excavator. The moment of inertia of the boom is 30-40% in the overall balance of the moment of inertia, and therefore significantly affects the power of the rotary mechanism and the duration of the cycle of the excavator, and the tilting moment from the weight of the boom is close to the tilting moment from the weight of the bucket with the rock.
When the weight of the boom is reduced, it is possible to increase the capacity of the bucket or the length of the boom without increasing the weight of the excavator, and these indicators are known to be the main parameters of the dragline. For example, it happened with an ESH 14.75 excavator. The initial parameters of the machine (serial numbers 1 and 2) are 14.65 (bucket capacity is 14 m³, boom length is 65 meters) then 10.75 (serial numbers 3, 4, 5) and 14.75 (serial numbers from 6 to 28) and ESH 20.65 (serial number 11). Now the factory produces an excavator ESH 15.90. The weight of the excavator has remained unchanged and makes up 1400 tons. Other main components of the excavator (tub, revolving frame, mechanisms) have not undergone significant changes.
