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Magazine "Kar'ernoe equipment"¹14-2004ã.
The EKG-4,6B Excavato is a full circle electrically powered straight shovel mounted on crawler tread and intended for excavating and loading into transport facilities heavy rock preliminarily loosened by blasting.
The excavator is widely used in open-cut mining of ore and coal, as well as in quarries for mining constructional materials utilized in building industrial, hydro-technical and other objects.
One of the essential conditions ensuring trouble-free operation of the excavator is to make the operator of each working shift responsible for servicing the machine. When changing over the shift it is necessary to record in the service log not only the condition of respective mechanisms and units, but to enter all the data pertaining to the repair work performed during the former shift.
The operator taking over the shift shall abide by the following:
1)inspect carefully the machine in general, checking the condition of the dipper body (front wall, jointing plugs), dipper door,dipper stick (end casting and beams), boom (welded joints ofthe feet), dipper trip mechanism, reliable jointing of the stickbeams with the end casting and attachment of the rear stop onthe stick, the degree of the dipper teeth wear;
2)check the availability of cotter pins, the condition of pinsconnecting the dipper with the stick, the bail and door; check thepresence of hoods enclosing the gearing;
3)check the tightness of joints, making sure there are no oilleaks in the crawler truck hydraulic system;
4)lubricate all the mechanisms in compliance with instructions given in section "Lubrication";
5)check the oil level in all the oil baths and top up, if necessary;
6)check the performance of oil pumps of propel mechanismand steering reduction gear units;
7)prepare the pneumatic system for operation, drain the condensate out of the air receiver and the oil trap, opening the drainvalves; engage the compressor having first checked that all valves connecting the system with atmosphere are tightly shut.Check the performance of the pressure relay. When operating in the colder time or the year, warm up the compressor making use of the electric heater pipe arranged under the compressor sump;
8)check the position of boom.
At the same time check and prepare for operation the excavator electrical equipment.
Before engaging the machine in digging:
1)proceed with a trial run at no-load of the main hoist andthe crowd and swing mechanisms (operation of gearing shouldbe smooth without knocks or other abnormal noise);
2)check the performance of brakes which should ensure reliable braking of the excavator mechanisms;
3)check the steering clutches and the propel mechanism performance in a trial run.
At least once a week it shall be necessary to inspect the machine more carefully, for which purpose use any spare time,especially during the unexpected breaks in operation. However, when the machine is operating in continuous duty, then reserve special time for such inspections.
In the course of weekly maintenance work:
1)tighten up the fastening bolts of electric motors, brakes,bearing caps, reduction gear units and main hoist stands, alsolighten up the dowel bolts jointing the crawler frames with themain (bottom) frame, the bolts of thrust clips of the axles of driving wheels, track rollers and track adjuster wheels;
2)check the condition of pins jointing the boom with the revolving frame, also of the axles of main sheaves and of the boomsuspending tackle;
3)check the tension of boom link rods and tighten up, ifnecessary, so as to ensure proper contact of both boom feet withthe seats in the front beam of revolving frame;
4)check the attachment of gearing on the electric motorshafts of the crowd and swing mechanisms;
5)check the condition of gearing; in case of minor scoreson teeth, file them up, without, however, interfering with the profile of teeth;
6)check the fastening of axles of track rollers, also the tightness of wedges in the lock of the main and crawler frames;
7)readjust the brakes of the mechanisms and the shearing,clutch of the crowd mechanism;
8)check, and if necessary, readjust the axial clearance of thecentre pintle;
9)check the condition of all cables.
About once every month it shall be necessary to carry out the monthly maintenance work, involving repairs which, if need be, are performed by a specialized repair crew. The monthly maintenance work includes the jobs listed in weekly maintenance and the following besides: preventive dismantling oi some units, minor repair and replacing of details subject to quick wear, etc.. The time expenditure for the monthly maintenance work is from 24 to 72 hours, depending on the excavator condition and the amount of repair work to be performed.
The monthly inspection of excavator is an integral part of the scheduled maintenance work and shall include the following:
1)inspect the metal structures; in case of detected cracks,,weld up, as instructed in section "Care of the Mechanisms andSystems, Adjustments and Repair Work";
2)tighten up the bolts fastening the crowd mechanism serviceplatform and the boom railing;
3)replace all worn fasteners: bolts, nuts, cotter pins, etc;
4)repair or replace the teeth and lock bar details of thedipper;
5)replace the dipper trip mechanism cable;
6)exchange the wooden bars of the boom bumpers;
7)check the condition of the friction linings of all the brakesand of the shearing clutch and replace the linings, if worn;
8)adjust or replace the saddle bearing sliders;
9)replace, if necessary, the dipper hoist cable;
10)reeve anew the boom cable, if necessary;
11)tighten up all loose connections of the house and cab details.
Besides, it shall be necessary to inspect all the units, mechanisms and systems, removing all covers, caps, hoods, etc. Lubricate the mechanisms in compliance with the instructions in section "Lubrication" and replace all worn details, including those which call for repairs at a specialized repair shop.
So as to ensure highly efficient operation of the excavator, abide by the following
1)operate the machine on level ground, only;
2)select a plotting scheme which makes possible to use themachine with maximum advantage;
3)always have sufficient transport vehicles at hand;
4)minimize the excavator idling time due to poor organization, lack of spare parts or tools, etc;
5)provide adequate lighting of the working site when operating in night time;
6)ensure the loosening of rock material prior to excavating.
7)keep a stock of blasted rock sufficient to ensure uninterrupted operation of the excavator for 36 to 48 hours;
8)maintain an average height of the face not execeding-10 m;
9)when engaged in digging, control the hoisting and crowding forces by means of the acceleration controller handle in sucha way that the dipper does not dig in too deeply into the ground,nor runs too shallow, taking only a thin layer of rock. The operator shall pay attention to the dipper travel, shifting the acceleration controller handles in due time;
10)when excavating heavy rocks, do not tolerate too longan outrigger of the dipper stick, as this is liable to decrease theshearing force of the dipper teeth;
11)unload the charge from the dipper into railway dump carsevenly spreading it along the car surface and avoid spilling therock on the ground or the railway track;
12)start swinging for discharging rock only with the dippercompletely charged; it saves valuable time to fill the dipper tofull capacity even making two runs, then to swing a dipper whichis only partially loaded;
13)start swinging for discharging rock only after the dipperis completely clear off the face;
14)when engaged in swinging, release the swing mechanismbrakes, slow down and stop the excavator top portion by swingelectric motors;
15)unload the dipper from a minimum height, which permitsunobstructed opening of the dipper door;
16)in case of a high-standing face, make sure to remove thecrest of rock formed at the top, since large lumps of rock in falling may not only damage the excavator but lead to serious accidents;
17)keep the dipper clean of clogged on dirt.
When a heavy boulder is encountered, dig it up from all sides, loosen with the help of the dipper and inserting the teeth underneath, lift up and unload carefully. Beware of large falling boulders, since they may be the source of accidents or lead to serious damage of the excavator.
The model ÝÊÃ-4,6Á Excavator is principally designed for excavating heavy rock, therefore when mining light or loose ground, set the machine on wooden flooring boards, which should have slinging means for gripping them by the dipper in order to move over to the next operating site.
If the excavator get stuck, dig up the ground around it and ensure a sloping surface shead of the tracks, laying flooring on the slope and running the machine along it.
Avoid travelling in self-propel over long distances (5 to 10 km), especially along sloping ground, so as to protect the machine from untimely wear of machine propel mechanism.
In the course of travel, guide the boom in the direction of travel, so as not to obstruct the proper view of the road. In this case the dipper should be suspended at a height of 1.5 to 2.0 m from the ground.
During eventual stops of the machine en route, lower the dipper down on the ground. Clean and lubricate the dipper only during stopovers, having received due permission from the operator.
Always sound a warning signal before starting operation.
To facilitate servicing, keep all passages between mechanisms clear of foreign objects.
Do not tolerate:
1)any impacts of the dipper against the tracks;
2)free dropping of the dipper;
3)slackening of the hoist cable when lowering the dipper onthe ground; the impacts of the cable being tensioned in the runmay result in damage of the excavator mechanisms;
4)swinging, once the dipper comes in contact with the ground,since this may result in damage of the stick, boom or the crowdmechanism;
5)any impacts of the dipper door against the side of therailway car;
6)direct impacts of the stick against the boom (replace thewooden bars on the boom, serving as bumpers, once they get wornor damaged);
7)engagement of the crowd or swing mechanisms to caterfor the propel of excavator;
8)impacts of the dipper sheave casing against the main sheaves of the boom;
9)impacts of the dipper stick against the saddle bearing stops;
10)lubrication or adjustments, tightening fasteners, etc, whilstthe mechanisms are running;
11)presence of unauthorized persons in the excavator houseoor the cab;
12)presence of people around the machine, when engaged inoperation.
Do not leave the dipper in suspension, if there is need to leave the cab.
Station the excavator at a safe distance when blasting operations are on the way.
To ensure safety against fire hazard, always keep the following fire-fighting equipment at hand: fire-extinguishers, boxes with sand and other means for combatting fire, in compliance with the regulations of the fire inspection division.
Store all the lubricating materials, including waste ends for wiping, in closed metal cases. If liquid lubricants should get inflamed, do not use water to extinguish the fire, since, as a rule, they are lighter than water, and in floating on the water surface shall continue to burn.
Do not use any tools for striking when opening gasolene cans, since there is danger of a spark igniting the fuel.
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