20 / 108
substantially less expensive than replacement or
reversal.
During the last 20 years, NOVEXA has
developed a unique reprofiling method which
allows, in a few days only and without dismantling
the gear, the original gear’s involute profile to be
restored, with a machining accuracy of 0.07 mm.
This on-site machining technique is specially
recommended in cases of pinion replacement
on a worn gear. Many clients do not take into
account the girth gear’s wear when replacing
their pinion. In such situations, at restarting,
meshing conditions are totally disturbed, and
the contact pattern is very poor due to the
incompatibility between the profiles of the
new pinion and worn gear. This situation often
generates very high vibrations coupled with
shocks during rotation (mainly on mills which
have an elevated rotation speed). As long as the
profiles of the pinions and gears are not matched,
vibrations will remain. The pinion’s wear speed
will drastically increase until the pinion’s wear
level reaches that of the gear so that their profiles
will finally match. By this time, the pinion’s
wear will be almost as high as it was before its
replacement and the customer will face the same
issues as before. In some cases, when the gear’s
maximum wear level does not exceed 0.5% of
the module (i.e. 0.15 mm for a module of 30),
a chemical running in process by a running-in
lubricant can be carried out. Otherwise, only a
mechanical reprofiling intervention on the girth
gear will allow the perfect involute profiles to be
restored and bring about a sustainable solution
(Figure 6).
After a reprofiling intervention including setting
and alignment, all meshing conditions will have
to be maintained in their optimal state by means
of perfect lubrication conditions and permanent
remote monitoring in order to have optimised
running conditions for many years.
Summary
‘Circular Maintenance Management’ is a holistic
approach to get the best out of rotary tubes in a
more lasting and transparent way without the risk
of unexpected shutdown. Beside the long-term
gain of performance, this solution offers a large
saving potential, making the payoff extremely
attractive.
f
Cost of production: A reduction of energy
consumption exceeding 3% through
proper lubrication can be achieved and
demonstrated using big data algorithms. A
long-term reduction of lubricant consumption
exceeding 50% against a commodity
lubricant can be achieved without the risk of
damage for the gear.
f
Cost of maintenance: Remote monitoring
and field inspection make the status of the
large gear transparent and predictive. The
system triggers ahead of time the need for
inspection, repair, reprofiling or replacement
to avoid costly emergency solutions. It also
offers large possibilities for automation like
condition-based lubrication systems to make
Industry 4.0 a reality.
f
Cost of unexpected shutdown: This is likely
to exceed
€
0.5 to 1 million combining the
cost of replacement of the gear (purchasing
cost and installation), the loss of production
(lead time until installation of the new gear)
and various additional costs (labour, third
parties and others).
With the combined competencies of
Klüber Lubrication, NOVEXA and DALOG,
cement manufacturers are offered an innovative
approach to maintenance management. The
combination of machine monitoring, onsite
inspection, repair lubrication and reprofiling
helps to reduce costs, makes maintenance more
efficient and thus supports the attainment of
sustainability goals.
About the authors
Nicolas Costa is Development Manager at
NOVEXA. He holds a Master’s Degree of
Strategy and Economic Intelligence from
Toulouse Business School and a Degree in
Management from Cergy-Pontoise University.
Nicolas Costa was Project Manager for XCase
application deployment, the remote monitoring
application for gear wear developed by NOVEXA.
Christoph Muschaweck has six years of
experience as Operations Manager at DALOG
and earned his Bachelor of Science in Industrial
Engineering at the Universidad de los Andes,
Bogotá.
Nicolas David is Global Head of Heavy
Industry at Klüber Lubrication. He holds an
MBA from ESSEC Paris and a Master’s
Degree of Mathematics from Paris Dauphine
University. Nicolas David has been working
for Klüber Lubrication in various management
functions for eight years. Prior to that, he was
Senior Consultant at Capgemini Consulting for
Paris and Germany.
Dr. Eva-Maria Mautner is Manager of
Gear Lubrication at Klüber Lubrication. She
holds a Ph.D. in Mechanical Engineering from
the Technical University of Munich and is a
technical specialist for open gear lubricants at
Klüber Lubrication. Prior to this, she worked as
research assistant at the Institute of Machine
Elements (FZG) of the Technical University of
Munich.
18
World Cement
July 2020