1978 Volume 13 Issue 12 Pages 903-917
In relation to the whirling of a propeller shafting, many conditions which were neglected in the conventional methods of calculation-more than three bearing supports, elastic support of the bearing section, gyroscopic effect of the propeller, shearing deformation of the shaft, etc.-were employed to evaluate accurately the natural frequency. Then, the following results were obtained:
(1) .The 3-point or more support is good to obtain a fairly accurate natural frequency.
(2) .The spring constant of the stern tube bearing must be measured as accurately as possible.
(3) .The gyroscopic effect of the propeller and the shearing deformation of the shaft have influence on the natural frequency by about 6% and 1%, respectively.
Furthermore, an analytical method in which the vibration response calculation could be conducted was established, and its utility was confirmed. Then, it was enabled to calculate the dynamic load acting on the bearing.
These developments enabled us to predict accurately the whirling of a propeller shafting at the stage of design, and increased reliability in the vibration problems.
