Page 15 - Industrial Technology EXTRA 7th June 2021

facilities and training. Those that qualify can
deliver services to operators as well as
manufacturers - as part of their programmes for
continuous improvement.

Incorporating modern designs
For manufacturers, developing
modernization packages is a very
important part of the support they
offer to operators. These programmes
can take advantage of materials and
manufacturing techniques that have
been developed since the locomotives
were launched. For the operators, these
updates ensure continued reliability and
extended service life for their assets.
However, these programmes require
considerable planning and time for product
design, development and testing. As a result, the
relationships between the OEM, the rail operator
and the parts manufacturer are very important; they significant, common challenges are torsional
must be long-standing if a successful outcome is to vibration and the physical space available for the
be achieved. components. During the three-year design process,
In one example, a rail OEM reached out to multiple coupling options were reviewed to
Stromag, Nuttall Gear and Guardian Couplings, all determine which solutions would best address these
of which are leading brands of Altra Industrial challenges. The chosen designs would be
Motion Corp., for support in supplying specialist recommended for a potential population of over
flexible and gear couplings. 10,000 locomotives.
Over the last three years, the OEM’s design and Within this fleet, the diesel engines produce up
engineering team has been working on new to 3,300 hp (2,500 kW) at 900 rpm and are
coupling solutions for both the main drive side and mounted on isolation mounts, while the gearbox
the power-take-off (PTO) of the diesel engine. One and alternator are hard-mounted to the chassis.
coupling is to be positioned between the diesel This can mean lateral movement of ±3 mm
engine and the gearbox, another between the laterally and ±4 mm vertically.
gearbox and the exciter and blower assembly and a As part of the design process, the OEM provided
third connecting the engine PTO to the air the input parameters for the design team to work
compressor. with. Stromag did the torsional vibrational analysis
(TVA) recreating the complete drivetrain and
Design challenges establishing that the values surrounding the engine
Each application has several design challenges – to gearbox coupling would present a considerable
some unique and some shared. The most challenge.

June 2021 • INDUSTRIAL TECHNOLOGY EXTRA • p15