BUCKET WHEEL EXCAVATOR KWK-910 - SKW

BIURO PROJEKTOWO-TECHNICZNE
BUCKET WHEEL EXCAVATOR
KWK-910

Mechanizmy
SAFETY AND COMFORT
The main operator's cabin is the control center of the machine. Comfortable
operator's work conditions facilitate taking advantages of a whole range of
the excavator's options and faultless interpretations of hundreds of
displayed data.
A comprehensive communication system ensures an access to all crucial
points of the machine and enables its safe operation.

GENESIS
Deposit exploitation conditions
- the basis for the project assumptions
for KWK-910 excavator.
After many years of exploitation, Turoszów deposits are
still evaluated to possess almost 500 mln tons of industrial
resources of lignite but their further exploitation will be largely
hindered by deteriorating geological and mining conditions.
The deposits of the first lignite deck and overlay to be exploited
are characterized by a highly complicated and irregular
geological struc ture (irregular depositing, faults,
multidirectional sloping, fractures and discontinuities) as well as
highly differentiated digging characteristics (from considerably
easily diggable to hard diggable layers, stone insertions and
interlayers of cohesive rocks). The excavators currently operated
in Turów opencast mine are not adapted to the efficient
exploitation in such differentiated deposits, which results in
their high mortality and, as a consequence, low actual capacity
as compared to their theoretical parameters. The mentioned
exploitation conditions of hard diggable formations in the
overlay of the first lignite deck made it necessary to design an
excavator:
�with resistance suitable for the required digging
parameters at the required capacity and with machine elements
and the bearing structure durable enough,
�with technological parameters such as the range of
lowering and slewing of the extension arms, manoeuvrability,
traction parameters, foundation pressure, etc. which ensure its
proper functionality on highly complicated, short and sloppy
exploitation frontlines.
The above mentioned requirements were specified in
details in the project assumptions for the “Contract of the main
contractor of a single-unit wheel excavator of KWK-910 type for
the exploitation of hard diggable formations” signed on
21.11.2003 by and between the Management Board of BOT
KWB Turów S.A. and SKW Biuro Projektowo-Techniczne
Sapkowski, Kanczewski, Wocka sp.j. in Zgorzelec.
That was the decision to construct the first in Poland
excavator for the exploitation of hard diggable formations; an
excavator designed especially for deposit conditions of BOT
KWB Turów S.A.

GENERAL CHARACTERISTIC
While designing an excavator meant especially for limited to 1.1.
deposit conditions of Turów opencast mine the configuration An exceptional advantage of the excavator is the
of the machine, working ranges, manoeuvrability and other solution of the right choice of the bucket wheel drive gearbox
technological parameters were assumed as well as the and durable joints for the gearbox and the bucket wheel shaft.
digging forces and the resistance of elements, systems and the The excavator of max. digging force 47 T with specific cutting
bearing structure of the machine to the expected dynamic forces of k L up to 200 kN/m is adapted to digging hard
loads. The vast experience of the mining exploitation and diggable fractions (interlayers) or selecting non-diggable
maintenance services, acquired during the exploitation of the layers. The excavator is equipped with a gearbox designed
existing machines was also taken into account. especially for the exploitation requirements of the lowest
Considering the requirements as for the technical parameters operational levels of “Turow” mine.
and the need to ensure a high exploitation reliability of the The most important mechanisms of the excavator
excavator the main machine systems were designed as a (gearboxes, bearing nodes) are equipped with built-in
special construction, i.e.: temperature and vibro-acoustic sensors in order to be able to
A detailed analysis and the selection of digging apply online diagnostics. This enables the exploitation of the
parameters was carried out, which resulted in obtaining their machine according to the technical conditions strategy, which
high values as well as considerable digging process largely facilitates early emergency threat detection and
smoothness (owing to the 1000 kW drive, with 16 buckets at proper planning of maintenance and its scope, at the same
the wheel of 10 m diameter). time eliminating the early preventive exchange of costly
In order to improve the durability of the machine elements.
elements, mainly in the digging system, the traditional The bearing structure of the excavator is
methods of their dimensioning in relation to nominal values characterized with high rigidity of all systems with flexible
and then allowing high overloads with coefficients of values of suspension of the digging extension arm (in order to rapidly
1.3 – 1.6 were abandoned. In the offered excavator high cut out dynamic and impact loads), which ensures high
nominal values are assumed and the overload coefficient is reliability and longevity as for the fatigue durability.

GENERAL CHARACTERISTIC
All the relative movements of the machine systems are at the tower ensures the insulation from vibrations generated
measured; the excavator is adapted to the application of the during the digging process. The casing of the bucket wheel in
manoeuvring movements' automatics, full monitoring and the lower part of the digging extension arm, apart from
remote control. It is also entirely secured against collisions, technological advantages – ensures good visibility of the
overloads, range excess, etc, with movement and force digging area for each position of the bucket wheel.
measures, terminal joints, sensors and probes. The inner transportation system ensures the collection
As the machine is designed for the operation in hard
3
of the output with max. capacity of 4400 m /h for each work
diggable deposits, which is connected with the existence of conditions.
impact loads of high values, the excavator is equipped with a
Summarizing, we are convinced that the domestic
system of tensometric sensors for the measurement of production of opencast mining basic machines is enriched
tensions in the crucial points of the structure. Such a system, with an important model of a new generation excavator for
constantly gathering data connected with the loads history the exploitation of hard diggable formations. With this
enables up to date evaluation of the bearing structure excavator we offer a modern, highly automated machine with
durability and in future will help to identify threats within the a visualization of the digging processes, control and
fatigue durability.
diagnostics, equipped with an industrial TV and diagnostic,
An optimal selection of the superstructure and warning, fire safety and other installations. The modern
undercarriage systems rigidness ensures advantageous work design, a method of digging, rotation, crawler drive system
conditions of the ball bearing. A special ball bearing of and transportation system are obvious advantages of our
9000 mm diameter is designed, with two-rows of 150 mm machine as compared to similar and much more expensive
diameter balls, of low pressure and high resistance to imported machines of this type. Solutions ensuring the
horizontal loads. The described advantages ensure high comfort of work are worth mentioning as well as work safety
exploitation durability of the turntable with increased loads and work conditions (air-conditioning, controllers, low level
during the operation at the slopes of 1:20 + 1:25 and at the
nominal lateral digging force 24 T.
The localization of the operator's cabin extension arm
of noise, vibrations, etc.), which makes this machine user and
environment friendly.

SPECIFIC FEATURES OF THE MACHINE
A crawler drive mechanism is equipped with the wellproven
fixture of the movement wheels of long life type,
facilitating the lubricating system. The control with an
inverter ensures a smooth regulation of the drive speed and
enables driving at various speeds of particular crawlers,
which facilitates turning.
Three-point support for the carriage is based on ball-andsocket
joints with modern bronze lining of high durability.
The steering with a hydraulic cylinder provides a turning
radius R= 25 m, unique for 6-crawler machines, and secures
the support system and undercarriage structure against the
loads resulting from the interaction of passive forces from
the foundation.
The slewing mechanism consists of four drive systems with
hydraulic drives cooperating with a toothed ring of the
module m=27. Flexible support for the moment levers and
securing devices in the hydraulic system buffer the effects of
side impact loads from the digging organ.
The system of the bucket wheel boom lowering is equipped
with a modern hoisting winch with a double drive
controlled with an inverter. Such a solution ensures a fluent
speed and boom lowering regulation with an option of
changing the direction of lowering without pawling of the
hoisting winch brakes.

The lowering of the discharge boom is implemented with a
hydraulic cylinder. This is a simple and easy solution which
ensures a wide range of lowering and which is suitable for
the implementation in a relatively light suspended pipe
structure for the discharge boom.
The digging system with 2 x 500 kW drives is an effect of
planning to reach the unitary cutting force of 200 kN/m. A
modern planetary gear of 1000 kW drives the bucket wheel
through an easily disassembled tooth coupling and a shield
fixed to the wheel with spring screws. A single layer wheel
with a self-cleaning chute is equipped with characteristic
spokes ensuring the transfer of the large side digging loads.
The digging system is suspended with joints to the
extension structure through a moment lever with a joint.
The overload device of an extremely short operational time
and high precision of the overload settings is a proof of the
highest technical level in the field of excavator security
against the effects of impact loads.
16 buckets are placed at the perimeter of the bucket wheel
of 10m diameter, which favourably decreases the dynamics
of the digging process and ensures the size reduction of the
output. The intentionally shaped geometry of the bucket
corners made of special alloy is a result of many years of
experience and tests carried in the conditions of hard
diggable deposits.
SPECIFIC FEATURES OF THE MACHINE

SPECIFIC FEATURES OF THE MACHINE
The double-belt system results in only one central hopper in
the slewing axis of the superstructure. It is easily accessible
both from the top and from the region of the belt chute of
the loading conveyor, which considerably facilitates the
exploitation as compared to single system machines with an
intermediate conveyor.
The excavator is equipped with belt conveyors with the belt
of B=1800 mm, exceeding the requirements of the
theoretical capacity of the digging system. This facilitates
the transfer of local pile-ups of the output and keeping the
machine clean. The removal of stones from the belt is
provided by the stone remover - a device already tested in
“Turow” opencast mine. The removal of stones can be
controlled from the main operator's cabin basing on the
industrial television display or from a special cabin of the
belt I operator.
The connection of the pylon with the slewing platform,
which is a crucial point of the machine structure in C system,
is designed and performed with due diligence.
The articulated joints of the structure are shaped so as to
ensure maximum resistance to side dynamic loads. It is
applicable to the counterbalance extension arm, the mast
and the connecting strands.

The elaboration of the technologically sophisticated
production of the support joints with a layer bronze lining
for basic machines is an innovation in the production of
such construction nodes.
The assembly of the heaviest elements of the structure
required the usage of special cranes of 100 t capacity at 40 m
range. The operation of the assembly of main elements of
the carriage – the tower, the counterbalance extension arm,
the mast with strands and the bucket wheel boom – entirely
assembled at the construction site – was performed with
the use of cranes of nominal capacity of 500t and 350t in the
shortest possible time of two weeks.
MANUFACTURING AND ASSEMBLY

EXPLOITATION
Capacity testing in a semi-hard overburden proved high
efficiency of the digging unit. No resonance effects in steel
structure were observed during exploitation and transport
of the excavator. Relative low dynamic stresses in steel
structure were registered during digging semi-hard
material.
Buckets of new design proved its efficiency in semi-hard
material. Self-sharpening bucket corners worked four times
longer then bucket teeth used so far reaching nominal
capacity of the excavator with relative low power
consumption.

Theoretical capacity - maximal
Bucket capacity - nominal
4400
910
3
m /h
3
dm
Bucket wheel diameter 10 m
Number of buckets 16 pcs
Cutting speed 2,176 m/s
Number of discharges 66,5 1/min
Bucket wheel drive power 1000 kW
Nominal cutting force 419 kN
Maximal cutting force 461 kN
Specific cutting force - maximal 200 kN/m
Digging heighth 15,0 m
Digging depth -2,0 m
Digging radius 30,0 m
Discharge radius 34,0 m
Slewing drive power 160 kW
Slew angle of superstructure ±180 °
Slewing speed (in bucket wheel axle) 8 - 30 m/min
Hoisting speed of bucket wheel boom
Feeding conveyor
5,6 m/min
- belt width 1800 mm
- belt speed 3,35 m/s
- drive power
Discharge conveyor
320 kW
- belt width 1800 mm
- belt speed 3,35 m/s
- drive power 200 kW
Discharge boom slew angle ±105 °
Travel speed 0 - 8,8 m/min
Minimal turning radius 25 m
Number of crawlers 3 x 2 szt.
Crawler plate width 2800 mm
Caterpillar chain pitch 520 mm
Crawler drive power 6 x 55 kW
Permissible ground inclination: longitudinal transverse
- exploitation 1:20 1:25
- transport 1:15 1:33
Average ground pressure 116 kPa
Total weight 1605 t
TECHNOLOGICAL DATA

SKW Biuro Projektowo-Techniczne
Sapkowski, Kanczewski, Wocka Sp.j.
Armii Krajowej 51A
59-900 Zgorzelec
skw@skw.pl www.skw.pl
Tekst: Wacław Sapkowski
Projekt graficzny: Jarosław Kowalczyk
Opracowanie: Marek Kowalczyk
KOPARKA KWK-910