LDW News 3 - Lloyd Dynamowerke GmbH

LDW
News
Information and news
from Lloyd Dynamowerke
Just like new:
LDW puts AEG machines back into action
The two largest-ever supplied AEG direct-current motors are shaped up
for additional decades of intensive use.
Steelwork has a very
long tradition in Ilsenburg
(Sachsen-Anhalt): It
already started back in
1595 with the foundation
of the „Ilsenburger
Kupferhammer“ company.
Another special feature
of the location are the
two largest direct-current
motors ever built by
AEG. The machines, at
about 4.5 metres height,
5.5 meters width and 7
meters length, weigh a
total of nearly 200 tons
each. Both of the milling
rollers produce powers of
14,300 kilowatts at 82.1
revolutions per minute.
In the former GDR,
both giants were installed
by VEB Sachsenwerk
under AEG‘s leadership
back in 1978. After nearly
30 years of constant use,
it was recently time to
put the machines through a well-deserved
rejuvenation.
Last year, Salzgitter Grobblech GmbH
tasked Lloyd Dynamowerke with this
job. LDW, being in possession of all the
construction and calculation documents for the
old AEG heavy equipment, was predestined
for the order. On top of that, LDW’s extensive
logistics competency meant shipping the
mighty machine parts did not present an
unsolvable challenge.
The order included constructing a new
stator and overhauling a second stator. To
The new stator frame for the roller motor in production in the
Bremen LDW factory. Our employees Markus Brandt, Branko
Delic, Kai Dombrowitzki and Bernd Oetting (from left) put the AEG
machines in shape for the coming decades.
keep the downtimes as short as possible,
LDW initially produced the new stators for
the top-roll motor. The old stators were then
replaced and reworked. In August this year,
it was exchanged for the old stators in the
bottom-roll motor. That one could then also be
overhauled and stored in Ilsenburg as a spare.
Now, nothing stands in the way of
continuing the tradition of steel construction
engineering at Ilsenburg.
• Drilling ships powered by
LDW machines
• Two-digit turnover growth
in 2007
• Compact generator:
75 percent weight
reduction
• Max-Planck-Institute
reaches for the stars with
LDW
Editorial
Dear readers,
No. 3
October 2008
in 2007, we put LDW back on the
growth track. A 15-percent increase in
productivity as well as the supporting
investments made by our investor CMP
have made that possible. Based on
the positive new course set in the past
years, with Kirloskar Electric we now
have a majority owner that will allow us
to continue advancing. At the same time,
the promise to our customers to provide
high quality at competitive prices remains
undeterred.
For the future, we can offer additional
exciting new developments: In
collaboration with institutes in the Bremen
University and Polytechnic, we are
successfully working on projects which
will massively reduce the weights and
volumes of powerful electric machines.
We will introduce some of these projects
to you in this issue of LDW News.
Enjoy the read and please contact
us if you would like to receive further
information on any of the topics.
Berthold Groeneveld
Managing Partner
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P. 2
P. 3
P. 4

Kirloskar acquires majority interest in LDW Double-digit growth in 2007
Management expects substantial growth opportunities for both companies
Kirloskar Electric Company Limited (KEC), one
of India‘s leading manufacturers of electrical
and power equipment, has acquired a majority
interest in LDW, Bremen. Both companies
are expected to benefit significantly from the
acquisition.
KEC and LDW both provide customengineered
design solutions to their
customers, and the product lines complement
each other well. „By combining these products,
we will be able to offer a wider range of
products at very competitive prices“, the
companies announced.
LDW is expected to provide the impetus
for Kirloskar Electric‘s accelerated growth
in Europe, while KEC will open up the
Indian market for LDW products. Also, both
companies can rationalise procurement
2
Drilling ships powered by
LDW machines
Lloyd Dynamowerke have secured
an order to build six motors and the same
number of generators for a drilling ship
being constructed for the offshore oil
company Transocean Inc., Houston. Four
almost identical sets of machines have
already been delivered or are currently
being manufactured for Transocean ships.
The drilling ships are being built by
Daewoo Shipbuilding & Marine Engineering
Co. Ltd. (DSME) in Korea, the world‘s
third-largest shipyard. LDW‘s client in this
project is Siemens Oil & Gas, Norway,
which provides the completed drive
systems for the ships.
The AC asynchronous generators
from LDW feed the on-board electrical
system and provide an output of 8.125
MVA at 11 kV and 720 RPM. The AC
asynchronous motors power the thrusters
and allow the ships to maintain their
positions. They also serve as propulsion
motors, providing an output of 5.5 MW at
2x2 kV and 750 RPM.
LDW was able to secure this order
due to the high quality of its machines,
which is extremely important in the oil and
gas industries. The drilling ships‘ motors
will be equipped with special 6-phase
coils, guaranteeing very high redundancy
and providing the highest-possible protection
against production downtimes.
activities to achieve economies of scale and
therefore reduce costs.
Kirloskar acquired the shares from
German investment company CMP Fonds I
GmbH. CMP had owned the majority for two
years, providing capital to facilitate LDW‘s
growth and paving the way for a successful
business year 2007. KEC now expects to
continue this development. While LDW will be
integrated in its existing business structure,
the German company will be „managed,
operated and reported as a measurable
separate organisation“, KEC announced.
Berthold Groeneveld will keep his shares in
the company.
The number of employees in Bremen –
currently about 250 – is expected to remain
the same or increase.
LDW has increased its turnover and profit
substantially in 2007. Following two years
of stable turnovers at €35 million in 2005
and 2006, this figure rose to €49 million
in the past year. The result of operations
improved by several million euros and returned
to the profit zone. LDW‘s business
situation has stabilised and the foundation
for additional growth has been built.
One important reason for the positive
development is the growing number of
orders from the shipbuilding industry, especially
for the operation of drilling ships.
An increase in productivity and closer ties
to regional suppliers have also reinforced
the upward trend.
LDW management expects a lasting
positive trend and further significant
growth of turnovers in the next years.

Compact generator: 75 percent weight reduction
Written off at one point, but now successfully developed and tested – the transverse flux technology spells big opportunities
When designing the powerful offshore wind
power plants, the weight and volume of
the generator systems play a decisive role.
The highest possible force densities and
torques, ideal efficiencies and controlled grid
feeding are additional desirable performance
characteristics in modern plants.
The transverse flux technology provides a
very promising solution here: Very high powers
can be produced with small construction
volumes. When the shaft rotates slowly at the
same time, it can even be used as a gearless
direct solution.
However, before it can be used in wind
power generation, the disadvantages of the
concept, for instance the torque ripples and
normal force fluctuations which lead to noise
and vibrations, need to be minimised.
These problems have now been solved by
the IALB Institute in cooperation with LDW.
The fluctuations can be nearly completely
prevented by using intelligent phase currentcontrol.
When compared with conventional
generators, the transverse flux generators
have up to 75 percent lower weight at the
same force density.
The 50-kilowatt transverse flux generator
prototype has already been successfully
tested in the LDW test area and concrete
inquiries have already been received from
the wind-power sector. The development
cooperation was sponsored by the Bremer
Investitions-Gesellschaft.
New, angular-shaped series without housing shell
Space-requirements for air-water heat exchanger eliminated with innovative design boasting air ducts in the corners
LDW is currently developing a series of
asynchronous machines with integrated water
cooling. The special feature in this series is
the angular contour in the so-called “shell-less
housing” design.
Based on the similarly angular-shaped
A5L series (high-performance compact
asynchronous machines), air ducts are
located in the corners of the square stator
plates, which act as heat exchangers
(however, here as the cooler for the interior air
circuit).
All the dissipated heat accruing in the
machine is drained off via the crown-shaped
cooling tubes. The optimised layout of the
cooling tubes on two pitch circles achieves
significantly higher utilization as compared
with a conventional design with cylindrical
water chambers. For the interior air, twice the
values result for the contact surfaces between
the stator core and the water conduction/heat
exchange surface at the same shaft height!
Of course the new series cannot compete
with our double-inlet standard series with
attached air-water heat exchanger regarding
the output coefficient, which is related to the
hole volume. But the advantage of the new
series is that – due to the large borehole in
the so-called „shell-less housing” design –
about the same power levels are achieved.
Therefore the space requirements for the airwater
heat exchanger are eliminated, which
has nearly the same volume as the machine
needing to be cooled.
The frame size range with shaft heights
from 450 to 630 mm and with power allocation
(at 6kV and 2p = 4) of 1600 kW to 4600 kW
are in planning.
This stator part in the 8.7 kNm generator
weighs 200 kilos. Dr. Norbert Götschmann
(r.), head of development at LDW, and design
engineer Wilhelm Hüneberg were decisively
involved in the development. Photo: Caspari
The stator frame for the new, compact asynchronous
motor series with integrated water
cooling. In these machines, the space requirements
for the air-water heat exchanger are
eliminated, which has nearly the same volume
as the machine needing to be cooled.
3

Max-Planck Institute reaches for the stars with LDW
Since as far back as the 60’s, LDW motors have been controlling a radio telescope the size of a football field
The Max-Planck Institute radio telescope receives waves from the
depths of the universe. Photo: N. Tacken, MPIfR
Ingenious employees ensure the success of the suggestion program
About 100 suggestions were submitted by
colleagues for the LDW company suggestion
program during the past year. The efforts paid
off: Exploitation of the first 60 suggestions has
already generated savings of 85,000 euros –
and that only involves the effects of improvements
that can be expressed in numbers.
In 2007, 43 individual employees and two
groups already participated in the company
suggestion programme. The system has
proven itself viable, and not only for the corporation
but also for the employees. As of April
2008, from the 60 assessed suggestions 38
improvements have been awarded with a total
of 13,300 euros; the highest single amount
was 4700 euros. Furthermore, a special
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Imprint
Publisher:
Lloyd Dynamowerke GmbH & Co. KG
Postfach 11 01 60
D-28081 Bremen
Telephone +49 (0) 421 4589-0
Telefax +49 (0) 421 4589-260
E-mail: vertrieb@LDW.de
Internet: www.LDW.de
Responsible: Marco Anlauf
The radio telescope in Effelsberg
near Bonn with a diameter of
100 metres is one of the largest
swivelling telescopes in the world.
The telescope area
is as large as a
football field. It is
operated by the
Max-Planck Institute
for radio astronomy,
which is dedicated
to researching
astronomical objects using radio
waves and infrared waves.
Especially remarkable is the
precision with which the telescope
can be controlled. It can be turned
90 degrees within five minutes and
be swivelled or tilted with a precision
of one-half millimetre.
The 60-metre long circular rail
around which the telescope revolves
also meets the highest demands:
The rails are adjusted horizontally
with a precision of 0.3 millimetres.
prize was raffled off during each quarter from
among the positively evaluated suggestions.
For instance in the 1st quarter 2008, it was
possible to win a travel voucher from Go-
Reisen valued at 800 Euros. This prize went
to Susanne Oehmicke in bookkeeping. She
made a suggestion for optimising office materials
requisitions to prevent waiting times.
Eugen Geis, who submitted a total of
four suggestions in 2007, has already been
drawn from the raffle pot twice. He won an
Asus Notebook in the 4th quarter. He made an
improvement suggestion in which aligning socalled
buckle fins can be omitted after cutting
to size. Previously he had already won the
special prize raffle in the 2nd quarter.
The telescope with a diameter
of 100 meters can be
positioned with the precision
of one-half a millimetre
The powerful and simultaneously
gentle drive for the ultra-sensitive
system is implemented with the
aid of LDW motors. The machines
from LDW were
supplied already
during construction
in the late 60’s. In
the early 80’s they
were replaced by
newer models,
and recently LDW
delivered the third generation motors
to the Eifel.
In total, 20 motors are needed
to achieve the high precision of the
telescope. Sixteen of them are used
to position the telescope itself; the
other four control the gradient of a
mirror to bundle the waves.
Due to the special requirements,
the motors were equipped with a
special filter design and a protective
hood to protect the machine from the
weather.
Savings already amounting to about 85,000 euros per year / Attractive prizes for implementable suggestions
Prize presentation for the first quarter 2008:
The improvement suggestion representative
Jens- Erik Borngräber, Managing Director
Berthold Groeneveld and Employees’ Council
Member Holger Warninghoff (from left) present
a travel voucher to Susanne Oehmicke from
bookkeeping.
Editing:
Kölling Medien-Service
Prager Str. 37
D-28211 Bremen
www.k-ms.de