The overhaul of a drag line EŠ-25 at the oldest OPM of Kolubara Basin, Field “B”, started on 17 June. According to the original planit shall be repaired simultaneously with the BWE 4. However, the drag line overhaul was postponed because of certain jobs to be done.
– Considering the age of the machine, which has been operating for several decades on the coal system, it can be said that the excavator is in very good condition – said the deputy head of Mechanical Service Mr. DušanŽivanović, who further elaborates:
– The scheduled overhaul time is shortened because the existing excavator base happens to have been damaged and therefore will be replaced with a new one. At the same time, damaged rollers, pins, geared rim and plain bearing of the central axis will be replaced. In addition, gearboxes of the steering, lifting and circular motion mechanisms will be taken off to be inspected in the company “Kolubara Metal”, based on which the damaged components will be replaced.
In an interview with Mr. Siniša Savković, the foreman of the electrical service group for excavators, we learn how much the installation of the new excavator base will be important for continuous and reliable production. On the specifics of this mining machine, he adds:
– When compared to the BWE that moves on tracks driven by a crawler mechanism, and with the turning motion of which is realized by blocking the appropriate track, the “marions” as well as the drag lines of EŠ type during their travel keep their superstructure connected to the substructure (basis). Also, for the moving,the EŠ relies on shoes that are connected with cams and axle shafts that lift the base plate and the back side of entire excavator making basic step just by pulling the plate. The motion direction is the taken position of circular motion of the excavator.
It is important to say that each drag line moves backwards with respect to the mast boom. In terms of the functionality, these excavators are extremely useful because of their abilities to make good maneuver and access as well as possibilities to operate in the bench and deep-cuts modes.
The envisaged electrical works are also related to the excavator basis. The repair works on the electrical equipment of the EŠ-25 include the removal of electric motors and generators, and complete fault diagnosis, replacement of bearings, machining of the rings and rotor collector. Also, an problem concerning the transfer i.e. the slip ring will be re mediated,which emerged in the operation of the excavator this year.
Once the old machine rehabilitation is completed, it will be back in operation with more confidence and security.
Source; MBK
