Page 42: of Offshore Engineer Magazine (Jul/Aug 2025)

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POWER COUPLING TECHNOLOGIES shafting of either thin wall steel or flament-wound carbon In many cases today, fexible couplings are part of a fber shafts are used to reduce weight and noise, while sim- larger and more refned engineering solution that in- plifying structural design complexity and cost. cludes motors and engines, couplings and shafts, and

With such a wide variety of fexible coupling styles avail- clutches and brakes. When considering these factors into able, selecting the right coupling is essential to ensure opti- the design of a cohesive vessel propulsion system, these mal system performance while ensuring long operating life components can reduce the number of interfaces, mini- and safe operation of the entire drivetrain. mize space requirements, and improve the overall eff- ciency of the drivetrain system.

TORSIONAL VIBRATION AND THE GROWING

CONCERN IN MODERN VESSELS MAINTENANCE BEST PRACTICES

Torsional vibration is the angular acceleration and de- Despite their clear importance within the drivetrain, celeration of a rotating shaft, superimposed to the steady- fexible couplings are frequently overlooked during rou- state rotation. This is heavily infuenced by the interac- tine planned maintenance. Improved system reliabil- tion of the properties of the rotating connected masses; ity, vessel uptime, and optimal life expectancy can be material stiffness, and the dynamic behavior of the entire achieved by: powertrain. In marine settings, however, this phenom- • Performing periodic alignment checks on enon has become more pronounced with the shift from y our drivetrain traditional low-speed internal combustion engines to me- • Verifying that hardware is properly torqued dium and high-speed propulsion systems, hybrid propul- • Scheduling inspections and maintenance in sion systems, and even electric motor-based drivetrains. accor dance with manufacturer’s recommendations

With new regulations being introduced as the world • Documenting as-found conditions during routine trends toward sustainability, the push toward cleaner en- inspections to trend wear and better prevent ergy has introduced new sources of torsional vibration catastr ophic failure through more complex operating conditions of the drive- Regular inspection and alignment checks can signif- train. High-pressure fuel injection methods, variation in cantly extend fexible coupling life expectancy and pre- cylinder combustion pressures from alternative fuel sourc- vent unplanned downtime. In systems where torsional es, and the integration of electric motors and generators vibration is also a concern, onboard measurement tools all work to contribute to the growing complexity of the and smart monitoring systems can provide real-time data torsional dynamics of modern vessels. to validate or refne TVA calculations and help you make

Because of this, performing a detailed torsional vibra- proactive decisions to ensure the optimal operation and tion analysis (TVA) has become a critical step in the de- safety of your propulsion system. sign of marine propulsion systems. A properly selected torsional coupling, confrmed by a careful TVA, can act THE FUTURE OF COUPLINGS as the well-tuned spring to help mitigate the harmful AND MARINE PROPULSION effects of torsional vibration while ensuring long-term With more regulations driving the evolution of the system stability. marine industry and the shift towards stricter emissions standards, digitalization, and the shift to alternative fu-

DESIGNING FOR EFFICIENCY AND RELIABILITY els, fexible couplings will continue to remain a critical

Modern fexible coupling design is about more than component in drivetrain safety and reliability. Their abil- simple torque transmission as engineers now consider a ity to integrate with new technologies and incorporate range of factors, including: new solutions into existing drivetrains positions them to • Torsional stiffness infuence and damping characteristics be a cornerstone of modern marine engineering for years • Thermal growth and alignment under loaded operation to come. Taking the time to ensure the proper fexible • Material selection for weight optimization coupling is being installed and maintained, along with • Integration with other drivetrain components, modern data monitoring solutions can effectively posi- like shaft braking and locking, and condition tion your operation to push towards a more refned and monitoring systems sustainable future. 42 OFFSHORE ENGINEER OEDIGITAL.COM