LOADING TOOLS
Caterpillar has recently updated the AC electric
drive system for Cat ® 7495 and 7495 HF electric
rope shovels
+50°C and altitudes of 5,250 m without derating.
“The reliable system also eliminates airborne
contaminants in the cabinet and lengthens service
intervals – for reduced costs and greater uptime.
Additionally, a new, faster propel transfer switch
cuts lag time by 75% for improved productivity.”
New technologies enable consolidating two
cabinets in the machinery house to create space
for easier maintenance access, while the updated
maintenance station is designed for integration of
current and future technology solutions, including
Cat MineStar™.
The drive system design uses common motors
in multiple applications, according to Cat. “That
means fewer parts to stock, improved parts
availability and simplified maintenance.” The new
motors also have higher power densities, smaller
frame sizes and optimised footprint, which aids
access, it added.
The Cat rope shovel electric drive system still
features elements such as fuseless insulated-gate
bipolar transistor modules. And, the on-board
maintenance station continues to aid technicians
in identifying faults and resolving issues. The new
electric drive system will be on all new production
7495 and 7495 HF shovels beginning in late 2020.
The system is not intended for retrofit, though
some elements, such as the fast propel transfer
switch, are available as upgrades to machines
already in service, according to Cat. Caterpillar
earlier in 2019 developed the propel drive system
upgrade for Cat ® 7495 and 7495 HF Electric Rope
Shovels. The upgrade reconfigures the crawler
undercarriage to allow drive shaft and tumbler
replacement from the outboard side, which
improves access and decreases downtime by
days. Improved component design extends
durability and increases component life to reduce
costs even further.
40 International Mining | MARCH 2020
The new propel design “slashes maintenance
time and enhances safety by enabling access to
drive components without removing the propel
transmission.” Additionally, Caterpillar engineered
the upgrade to be a direct replacement. No
machining of the crawler frame is required for
installation.
The new design also is robust. Thrust loads are
evenly distributed on large tapered roller bearings
as opposed to bronze thrust plates, and the
bearings are sealed and continuously purged with
fresh grease to keep them free of contaminants.
The result is increased durability in harsh
environments and alignment with 25,000-hour
planned rebuilds. The propel drive system
upgrade has already operated successfully for
thousands of hours in field validation.
Uralmash starts production of new
EKG-18
Russia’s Uralmashplant JSC (UZTM) recently
commenced the production of a modernised
version of its flagship power shovel model EKG-18
developed together with
specialists from coal miner
UK Kuzbassrazrezugol.
Qualitative changes aimed
to increase its reliability,
service life, and safety
have been introduced in
the design of most of the
main units of the machine.
The EKG-18 is a serial
rope mining shovel model
that has been supplied by
Uralmashplant since 2011.
The new, modified version
of this model, the EKG-
18M, was developed taking
into account the eight
years of experience of
operating these machines at customers' mines.
According to the Chief Designer of rope shovels,
Dmitriy Melnikov, the new model has an improved
bucket door mechanism that allows reducing the
truck loading cycle. The modernisation also
included the improvement of the yoke
manufacturing process, and design improvements
of the boom and the carriage. The housing of the
modernised model has improved sealing and
safety, and the cabin provides for the better
comfort of the operator.
There are also some new options in the
information system of the machine, namely a help
function which displays manuals and drawings of
the machine assemblies for the machine operator.
A boom jacking protection system is also provided
for protecting metal structures and ropes from
premature wear.
At the same time Uralmashplant has
implemented new procedures aimed at improving
the quality of products including the development
of stricter requirements for suppliers and
additional quality control of the machine parts at
all stages of the production process.
The modernisation of the EKG-18 was
conducted with the direct participation of experts
at UK Kuzbassrazrezugol (UMMC holding), which
is the largest customer for these machines; it
operates ten power shovels of this type.
“Any machine, as reliable as it may be and
despite its high performance values, needs to be
continuously improved. Our aim is to create
reliable, user friendly, and easy in operation power
shovel fully fulfilling the client's needs,” says
Melnikov.
Mae Moh gets seven Hitachi EX3600
electrics
On January 14, 2020, Hitachi Construction
Machinery Thailand completed the handover of
seven units of mining excavator Hitachi EX3600E-
6LD to major contractor Italian-Thai Development
Public Ltd, for use in Project 9 at the huge Mae
Russia’s Uralmashplant has begun production of
the modernised version of its flagship power
shovel model the EKG-18