EKG-20A
EKG-20A crawler
excavator and its modification is intended for excavation of I and II category
ground without preliminary blasting, III, IV and V categories - with
preliminary blasting, with stacking or loading to transport facilities
including boxcars. EKG-20A excavator effectively suites haul trucks with
capacity from 180 to 250 t.
Working equipment involves rack crowd mechanism with two-beam stick and all-welded boom of box-type section providing better excavation of heavy faces of lumpy and malexploded rocks. Dipper raising by cable, non-pulley type with automatic balancing of hoisting cable strands. The dipper is welded-casted with double walled back and self-tightening teeth with cottering.
The excavator has filter ventilating plant providing cleaning of air forced to machinery house and creating exhaust air pressure in the machinery house at closed doors.
The brakes of the main mechanisms are of block type driven pneumatically for unbraking.
Carrier - two-crawler. Crawler mounting is of open low-support type with separate drive of each crawler belt providing availability for inspection and repair. Driving wheels (sprockets) are raised and free of support reactions. The carrier is equipped with cable reel with capacity of supply cable not less 250 m. The stretch of crawler belts is performed by hydro cylinders located on balance shafts. Forced ventilation is used in propelling motors. The cams of driving wheels are changeable.
The main bearing structures of excavator - lower, revolving, crawler frames, gantry made of low-alloyed steel. The boom and stick - of high-strength steel.
Operator’s cab - two-storied. The lower storey is intended for arrangement of bench tools and spare parts storage. The upper storey includes two sections - welfare and operation, they are hermetic and heat and vibroinsulated.
The revolving frame is equipped with fire-prevention system actuating automatic alarm system and carbon dioxide fire extinguishers. The support-revolving mechanism engages the center journal, rigidly fixed on the lower frame, integral ring gear and roller disk, the holder of which is centered on the center journal. The roller disk has conic single-shoulder rollers rotating on cantilever axes.
The main mechanisms of excavator has separate control d.c. drive of thyristor convertor-motor (TC-M) system with semiconductor electrical machine excitation. The drives of the main mechanisms are controlled with two manual non-contact one-axis and two-axis brackets (one-axis - for crawler-transfer, two-axis - for rotation, hoisting-transfer).
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Parameters |
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Capacity of main dipper, m3 |
20 |
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Capacity of changeable dippers, m3 |
16; 25 |
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Maximum digging radius, m |
23,4 |
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Digging radius at floor level, m |
15,2 |
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Maximum digging height, m |
17 |
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Maximum dumping radius, m |
20,9 |
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Maximum dumping height, m |
11,5 |
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Radius of rear stick part, m |
10 |
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Clearance under revolving frame, m |
3 |
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Crawler track length, m |
12,55 |
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Width of crawler belt, mm |
1800 |
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Average ground unit pressure during moving, kgf/cm2 |
3,16/2,8 |
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Average ground unit pressure during moving, kPa |
320/286 |
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Maximum load on dipper hanger, kN |
2000 |
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Design cycle duration at 900, s |
28 |
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Maximum climbing angle, deg |
0,20(12) |
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Traveling speed on horizontal track, km/h |
0,88 |
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Supply mains voltage, kV |
6 |
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Electric drive type |
TC-M |
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Power of mains motor, kW (transformer, kW) |
2250 |
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Working mass, t |
1075 |