Exam Question

(a) Effect of wear down in main bearings on the condition of the crankshaft and propeller shaft system:
Wear down of main bearings causes misalignment, leading to the bending of the crankshaft. This bending increases operational stresses, particularly during rotation.
The centerline of the crankshaft and propeller shaft may form an arc due to uneven wear, leading to improper alignment with other engine components.
Worn bearings cause the intermediate crank throws to deflect, resulting in the crank opening at the bottom position and closing at the top. This can compromise the smooth rotation and operation of the crankshaft.