POWER TRANSMISSION
specialist, high-strength steels. It has
upgraded its machinery with the
installation of a series of Siemens drives
and Flender gear units on systems for
moving steel between furnaces and
processing units such as rolling mills.
Previously motors without a gearing
mechanism were installed but the units
proved unreliable — and in heavy
industry, downtime is very expensive.
Jim Cossar, Corus manufacturing
manager, said: ‘Speed matching was
becoming an increasing problem
for the roller tables conveying steel
from the furnaces.’
This upgrade has contributed to a
claimed 30 per cent increase in
throughput and ‘significantly’ improved
efficiency. Production improvements
such as these have led to the plant
trebling output over the last two years.
Also for the steel industry, Renold
Gears has produced its heaviest pair of
wormwheel gearboxes at Milnrow near
Rochdale. Weighing in at some 25 tonnes,
they are destined for installation at an
Asian steel mill as part of a mechanism
used to reform recently cast steel billets
into thinner sections.
Screw-down units are designed to
apply sufficient force to squeeze steel into
the required section widths — the units
are manufactured as pairs and transmit
loads from massive 220kW motors with a
reduction ratio of 21.5:1, meaning they
have to withstand enormous static
torques of up to 53,000Nm.
Materials handling also uses power
transmission technology at a materials
recovery facility operated by Nordic
Recycling in Tilbury, Essex. Ken Mills
Engineering (KME) built an advanced
materials handling system for the plant,
which uses more than 50 gearboxes
supplied by Oxfordshire-based Nord
Drivesystems, to enable the extraction of
different recyclable materials.
The facility incorporates a number of
screening stages and automatic balers
linked by a sophisticated conveyor
system over several hundred metres. The
system is driven by the 50-plus Nord
SK9000 gearboxes, which employ helical
bevel gears to offer a claimed efficiency of
over 95 per cent — which leads to
significant savings as the plant typically
runs for about 16 hours a day.
These gears were chosen as they can
provide a right-angle connection
necessary for the conveyor system. They
were also deemed to be extremely
The gearing
system for
Wembley
Stadium’s sliding
roof panels is a
low-speed,
high-torque
design and can
move the roof into
place within
15 minutes
reliable, which is essential as the plant
has a nominal capacity of recycling 25
tonnes of material an hour.
It is not only heavy industry that
needs power transmission devices.
Watching a football match at Wembley
Stadium no longer means getting wet if
it rains, thanks to a system of sliding
roof panels driven by Brevini Power
Transmission gear units.
The gearing system needed to be a
low-speed, high-torque design, and able
Because of their efficiency, small size and high
reduction ratio 34 Brevini planetary gear units
were chosen to move Wembley’s roof panels
to move panels weighing up to 330
tonnes at about 30mm/sec. Thirty-four
Brevini planetary gear units were
chosen for the job due to their
efficiency, small size and high
reduction ratio. They move the panels
in place to keep the spectators
completely covered within 15 minutes
and it is a major addition to comfort at
the new stadium.
40 the EnGIneeR 14–27 JULY 2008
The importance of power
transmission was also the focus of a
recent BBC TV Top Gear programme.
In one of the team’s recent stunts they
arranged a race between a G-Wiz
automatic electrical vehicle and the
Ford Shelby Mustang GT.
Of course the G-Wiz had to have a
touch of upgrading to make a race of it,
and with the help of refinements such
as four huge electric motors driving the
rear wheels via a custom transmission
system consisting of drive belts and
pulleys developed by Brammer UK, the
Lynch Motor Company and Exeter
University, the team upped the car’s
top speed considerably from the
production version’s 40mph (65kph).
In the end it did beat the Mustang,
showing what can be done with a bit of
attention to the power transmission
mechanism.
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