A geared slow speed diesel propulsion plant with a fixed pitch propeller has some advantages in propeller efficiency and cost, compared with that of a controllable pitch propeller. However, it may have the disadvantages in torsional vibration characteristics because of its wide operating rpm range unless properly designed. Authors have made a non-linear torsional vibration model for the geared slow speed diesel propulsion shafting with the fixed pitch propeller, taking account of the existence of gear backlash. By this simulation model, taking account of the existence of gear backlash. By this simulation model, transient conditions, resonant conditions, one cylinder fuel cut-off condition, etc. have been simulated. As a result of the said simulation, it has been confirmed that there is no torsional vibration problems in normal operating condition, but there occurs severe torsional vibrations in resonant condition or one cylinder fuel cut-off condition, which are promoted by the existence of the backlash. However, abnormal alternating torque due to the severe torsional vibrations can be detected by the installation of alternating torque alarm on the flexible coupling and can be brought to the attention of the crew for their action of the main engine speed reduction. Further, it is confirmed by the simulation that the maximum load born on the gear tooth and flexible coupling are within the permissible range of the equipment.
Non-linear torsional vibration analysis for geared slow speed diesel propulsion shafting with fixed pitch propeller
Nichtlineare Drehschwingungsanalyse fuer Getriebeantriebswellen mit Festpropeller und langsamlaufendem Dieselmotor
1983
8 Seiten, 13 Bilder, 2 Tabellen, 2 Quellen
Conference paper
English
Torsional vibration of shafting on ducted propeller ship
Automotive engineering | 1977
|Measurement of torsional vibration stresses in marine propeller shafting
Engineering Index Backfile | 1951
Torsional vibration of shafting
Engineering Index Backfile | 1933
|Torsional vibration of geared turbine propulsion system
Engineering Index Backfile | 1953
|