As mineral seams close to the surface get depleted, the need to dig deeper, more
expansive mines has grown. This trend has significantly increased the demands
on mine hoist performance. Mine hoist systems are getting larger with increased
material skip capacities and faster hoist speeds (up to 50%) in recent years.
Mine hoist OEMs and mine operators are continuously challenged to develop
technologies that transport material, crews and equipment to the surface more
quickly and safely. Larger hoist lifting capacities, along with deeper shafts (up to
3150 m) and higher speeds (up to 20 m/sec), significantly increase hoist drive and
braking torque requirements.
There are three basic mine hoist types currently in use today. Blair multi-rope hoists
are installed on the world’s deepest mines. Single- and double-drum hoists are the
most common types used and are typically found in North America, South Africa
and South America. Friction (Koepe) hoists use multiple ropes which give them a
higher payload capacity, and these are typically used on less deep mines.
MEETING THE NEED FOR RELIABLE BRAKING SOLUTIONS
ON ALL TYPES OF MINE HOIST APPLICATIONS
As a recognized global leader in mine hoist braking technologies, Twiflex
offers a full line of mine-ready systems, including their popular VKSD, VSD and
VMS brake ranges. All the brakes are spring-applied and hydraulically released to
provide a fail-safe system for emergency stopping when there is a power failure or
mechanical problem with the drive. The brakes are available as dual-spring (two
spring modules) or mono-spring (floating) versions.
ADVANCED MINE WINDER BRAKING TECHNOLOGIES
Twiflex mine winder disc brakes are designed to statically
hold twice the weight of the cables and fully loaded skip or
crew cage at the bottom of the mine shaft. They provide
enough braking torque to deal with the static out-ofbalance
load, in addition to the dynamic stopping duty
requirements.
For mine hoisting, brakes are typically rated between 62 kN
and 320 kN braking force, at a nominal 0.4 coefficient of
friction with a 2mm gap between brake pad face and
brake disc. At this rating, Twiflex brakes are designed for
more than 2 million braking cycles to meet exacting hoist
requirements.
To assist with maintenance, Twiflex brakes incorporate a
monitoring system to signal brake-pad wear and loss of
braking force. All Twiflex modular brakes are subject to a
cycling test and pressure test before leaving the factory.
For mine hoists, all critical brake components undergo
non-destructive testing.
SUPERIOR BRAKING PERFORMANCE ON LARGE WINDERS
Twiflex Model
VMS3-SPS
caliper brakes
installed on a 20 ft.
diameter doubledrum,
single-clutch
hoist at a Canadian
gold mine.
Installed on many mine hoists worldwide, the VMS3-
SPS is an improved design from the VMS family, offering
an additional 20% braking force. The spring-applied,
hydraulically-released brake offers up to 276 kN braking
force at 3mm air gap between brake pad face and disc
face with a 0.4 coefficient of friction.
Ideal for use on larger mine hoists, the VMS3-SPS is
totally sealed to provide excellent corrosion and dust
protection. The improved design includes tamper-proof
pad wear adjustment, external pad retraction and Twiflex’s
unique “Park Off” feature where the brake can be set to
remove all stored energy, making it completely safe for
pad replacement and maintenance. Like all other Twiflex
modular brakes, the VMS3-SPS can be serviced using
standard equipment without the need for special tooling.
LATEST BRAKING INNOVATIONS FROM TWIFLEX
Twiflex recently introduced the VSD series brakes for
industrial applications including mine hoists. The new
brake incorporates several of Twiflex’s latest technological
improvements.
The compact, cost-effective VSD design includes Twiflex’s
exclusive “Park Off” feature, increased braking forces with
lower operating pressures, a floating version option, and
improved modular flexibility not available on similarly rated
brakes.
VSD spring-applied, hydraulically-released disc brakes
are available in a range of sizes with braking forces from
100 kN to 220 kN. The brakes are designed for fast and
easy installation, adjustment and pad changes.
PROVEN BRAKING SOLUTIONS FOR SMALLER HOISTS
Available in a range of sizes, with braking forces from
26 kN to 119 kN, Twiflex VKSD brakes are ideal for use on
smaller mine hoist applications.
The VKSD caliper is a spring-applied, hydraulically-released
disc brake which is comprised of two spring
modules located on either side of a mounting plate. The
plate can be made in any thickness to accommodate brake
discs of 20 mm thickness or over.
Similar to the other Twiflex brakes in this range, the VKSD
includes the “Park Off” feature, easy brake pad and seal
change, simple adjustment using standard tooling and the
ability to re-rate the brake without changing the
spring pack.