ENGINEER TO ENGINEER
In brief
A dental laboratory
commissioned special-purpose
machinery manufacturer, Jonas &
Redmann, to design and build an
automated production cell capable
of producing and testing fi ve
million mixing nozzles per year.
The short cycle time of 1.5 seconds
was a problem when it came to
the essential 100% fi nal testing.
The four-piece mixing nozzles are
assembled in the production cell.
Final testing had to be based on
a friction coeffi cient test (< 0.5
Nm) on the mixing mechanism
of the assembled nozzle. Kistler
used a type 4502A torque sensor
and the maXYmos BL evaluation
system to check the torque curve
for each individual product. The
measurement value produced by
the torque sensor generates an OK/
NOK signal transmitted directly
to the control system, so that any
product with an out-of-spec torque
curve is automatically rejected.
Dynamic Load Monitoring (UK)
of Southampton has delivered two
load cells to Catena Inspection &
Engineering Services for use at
a nuclear cleanroom site where
propulsion systems are developed
for the UK’s Ministry of Defence
(MOD). The load cells were of
500kg and 1,500kg capacity.
In Vilagarcía de Arousa, Spain,
problems with the sewage network
comprising 52 pumping stations
were leading to pollution events
and a EUR 200,000 annual
maintenance bill. To resolve these
issues, the city council partnered
with experts from Sulzer. A survey
revealed that some pumps were
old, worn out and in need of
replacement. Others were in
good condition, but were the
wrong size or specifi cation to
cope with the demands placed
upon them. In addition, primary
screens installed before the inlets
of many pumps were becoming
blocked with sanitary wipes. The
proposal involved a systematic
reconfi guration of the equipment
in the network. Some pumps
would be replaced with new
high-effi ciency designs, sized to
NSK self-Lube bearing units save
steel plant €292,136
An international steel plant was struggling with
up to three bearing failures a year on a rotary
coal valve used in its ore preparation process.
In addition to the cost of replacement bearings,
the failures had knock-on e ects in terms of
lost production, downtime and damage to
associated components.
NSK conducted a full application review,
which included a temperature survey and a
bearing condition report. The review revealed
that not only was the current bearing inadequate
for the high process temperatures, but also
the lubrication quantities and frequencies were
incorrect. As a result, NSK recommended a
customised RHP Self-Lube HLT bearing insert
within an RHP Self-Lube cast iron FC housing,
plus a bespoke adaptor plate and a special heatisolating
spacer.
RHP Self-Lube units include two basic
components, the insert and the housing. Each
unit consists of a sealed single row ball bearing
with spherical outside diameter and extended
inner ring mounted in a anged housing made
from a rigid one-piece design. Importantly,
spherical seating accommodates any initial
misalignment when mounting. Self-Lube
inserts feature hardened, high-quality steel for
inner and outer rings, and optimised internal
geometry, a two-piece riveted steel cage, highperformance
grease and durable silicone seals.
For the rotary valve bearings at the steel
plant, the expert
team of NSK
engineers also
recommended
changes to
the lubrication
quantities and
frequencies. To
ensure correct application, NSK oversaw the
tting of the new bearings as part of a trial.
After more than 12 months the bearings
still had not failed, delivering a total annual
cost saving for the customer of €292,136. This
calculation includes cost savings associated
with the elimination of downtime due to bearing
failures; fewer bearing purchase orders; reduced
bearing replacement time; and the removal
of compressed air cooling to help control the
overheating of previous bearings.
Longest-ever crane to be installed for
long-range Airbus jet production
A Demag process crane will literally play a
supporting role in the assembly line of the new
Airbus A321XLR in Hamburg. Travelling on a path
of 82 metres, it will have a span of no less than
106 metres – making it the longest crane that
Demag has ever built. It will cover the entire area
of the factory bay. The double-girder suspension
crane will travel on six crane runways, which will
be installed parallel to each other at distances
of 24 and 10 metres under the
factory roof.
Each of the four hoist units
has a load capacity of 6.25 t,
providing a total load capacity of
25 tons. The crane is operated
by radio control. Depending on
the selected combination, the
hoist units can be operated as single units or in
synchronised mode.
The crane trolley features a slewing
mechanism with four Demag hoist units
installed in a rectangular arrangement. They can
be adjusted relative to each other in the X and
Y axes, enabling the crane to handle the various
fuselage panels and sections of the Airbus
A321XLR. In this way, the crane system o ers
additional freedom: in the rotational axis and for
the position of the four hoist
units relative to each other.
The semi-automated target
positioning function will ensure
gentle, safe and reliable handling.
The crane will be used in twoshift
operation from April 2022.
shift 88 www.operationsengineer.org.uk Winter 2021
/www.operationsengineer.org.uk