Method and device for evaluating shafting alignment of ship

An evaluating device for evaluating an alignment of drive shafting of a ship including a crankshaft of an engine, an intermediate shaft, and a propeller shaft, the evaluating device comprising:

• a data input unit for inputting specification data of the drive shafting, data regarding an evaluation condition and an inclination of the crankshaft of the engine and an inclination of the intermediate shaft, and data regarding hull deformation due to variations in draft and hull deformation due to thermal expansion of the engine;
• a bearing position calculating unit for calculating respective bearing positions of the crankshaft, the intermediate shaft and the propeller shaft using the specification data;
• a shafting displacement calculating unit for calculating a displacement at a predetermined portion of the crankshaft using the bearing positions calculated by the bearing position calculating unit and data regarding the crankshaft and the intermediate shaft among the specification data;
• an evaluation index calculating unit for calculating an evaluation index using the displacement calculated by the shafting displacement calculating unit;
• an evaluating unit for performing an evaluation by comparing the evaluation index calculated by the evaluation index calculating unit and the evaluation condition;
• and
• an output unit for outputting an evaluation result obtained by the evaluating unit, wherein
• the bearing position calculating unit includes a bearing height calculating unit for calculating a bearing height with respect to a height reference position and a bearing horizontal position calculating unit for calculating a horizontal position of a bearing with respect to a horizontal reference position,
• the shafting displacement calculating unit outputs a displacement of a portion corresponding to an intersection of a crank arm and a journal as well as displacements of respective bearings,
• the evaluation index calculating unit includes a crank deflection calculating unit for calculating vertical and horizontal crank deflections based on the displacement of the portion corresponding to the intersection and a bearing load calculating unit for calculating a bearing load based on the displacements of the bearings,
• the evaluating unit includes a crank deflection evaluating unit for performing an evaluation by comparing the vertical and horizontal crank deflections calculated by the evaluation index calculating unit with respective evaluation conditions and a bearing load evaluating unit for performing an evaluation by comparing the bearing load calculated by the evaluation index calculating unit with an evaluation condition, and
• the output unit includes an evaluation map creating unit for outputting an evaluation map which displays an evaluation result of an evaluation of the crank deflection by a combination of the inclination of the crank shaft and the inclination of the intermediate shaft integrated with an evaluation of the bearing load on a plane of two-dimensional coordinates.