TPT September 2009

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Technology Update
62 September 2009 ›
Specialist bending of copper
allows consistent high voltage
TRACTO-TECHNIK, Germany, has
supplied a manufacturer of on-load tap
changers (OLTC) with a TUBOTRON 20
RL fully automatic right-and-left-hand CNC
bending machine.
The machine is used for bending the
conducting copper rods, which are installed
at the OLTCs. Tap changers are important
components within the field of high-voltage
technology and their main function is to
regulate transformers by compensating
voltage jitters.
Although bending of copper rods can initially
appear to be a straightforward process,
there were some particular difficulties in this
special case – the copper rods with a bigger
outside diameter were insulated with paper.
In order to prevent damage of this insulating
layer the bending machine was equipped
with special pressure dies, consisting of
several counter rolls.
Furthermore, some of the rods were provided
with connecting plates, even before the
bending process.
Therefore, the
c o r r e s p o n d i n g
collet chucks have
special gaps that
hold the plates
and allow for a
defined and precise
rotational alignment
of the plate prior to
the first bend.
The TUBOTRON
20 RL has an exposed and compact
bending head that ensures maximum
bending space when producing even
complicated tube figures with an outside
diameter up to 20mm.
The company claims that intuitive
programming of all axes is performed
via SIMATIC touch panel PC control with
menu-driven user guidance. The bending
machine has a servo-electric bending drive
that allows for precise bending with highest
repeat accuracy. Maximum bending speed
is 450°/s.The Tracto-Technik product range
covers CNC tube bending machines up to
170mm OD, semi-automatic and one-axis-
controlled tube bending machines, tube-
end forming machines and tube measuring
systems as well as piping software
solutions.
Tracto-Technik GmbH & Co KG –
Germany
Fax: +49 27 2595 4033
Email:
Website:
 Bare and insulated
copper rods for
on-load tap chargers