EKG-12
EKG-12 crawler
excavator and its modification with elongated working equipment EKG-9US are
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-12 excavator effectively suites haul
trucks with capacity 75 and 110 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. Loosely falling dipper door with widely positioned hinges excluding
dynamic contact with stick. The excavators are equipped with boom-raising
mechanism. The excavators have filter ventilating plants 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
excavators - 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 excavators
have separate control G-M system d.c. drive. 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).
Parameters
Capacity of main
dipper, m3
12
Capacity of changeable
dippers, m3
14; 16
Maximum digging radius,
m
21
Digging radius at floor
level, m
14.3
Maximum digging height,
m
15
Maximum dumping radius,
m
18.5
Maximum dumping height,
m
10
Radius of rear stick
part, m
9.3
Clearance under
revolving frame, m
3.1
Crawler track length, m
10.3
Width of crawler belt,
mm
1400/1800
Average ground unit
pressure during moving, kgf/cm2
2.85/2.25
Average ground unit
pressure during moving, kPa
280/220
Maximum load on dipper
hanger, kN
1225
Design cycle duration
at 900, s
26
Maximum climbing angle,
deg
0.26
(15)
Traveling speed on
horizontal track, km/h
1.1
Supply mains voltage,
kV
6
Working mass, t
655/668
Generator-motor system
with thyristor excitation