Aux 1 Unit 11 Q8

1 / 10

What design feature is commonly used in plain bearings to allow for alignment changes due to vessel conditions?

A) Fixed, non-movable bearing blocks

B) Spherical bearing housings that allow the bearing to tilt slightly

C) Completely rigid and unmovable bearing mounts

D) Enlarged bearing surfaces to allow for play

2 / 10

How do propulsion shaft intermediate plain bearings accommodate changes in alignment due to varying vessel conditions, such as loading or hull flexing?

D) By reducing the size of the bearing

C) By increasing the size of the bearing housing

B) By incorporating a self-aligning feature that allows the bearing to adjust to minor alignment changes

A) By using fixed, rigid bearing mounts

3 / 10

How does the complete bush in the aftmost bearing help to prevent misalignment as the shaft exits the vessel?

A) By allowing the shaft to move freely

C) By restricting the shaft's movement entirely

D) By increasing the shaft's rotational speed

B) By providing continuous support around the entire shaft circumference, ensuring proper alignment and preventing lateral movement

4 / 10

In what scenario would longitudinal movement of the propulsion shaft be most critical?

D) When the shaft is not in use

B) During rapid temperature changes, such as when transitioning from cold to warm waters

A) When the vessel is stationary

C) When the vessel is docked

5 / 10

What could happen if the propulsion shaft is not allowed to move longitudinally within the bearings?

D) The bearing would automatically adjust.

C) The shaft would operate more smoothly.

A) The shaft would become more efficient.

B) Excessive stress could build up, leading to bearing failure or damage to the shaft.

6 / 10

What is the primary reason why intermediate bearings may only have a bush in the lower half?

A) To increase the overall cost of the bearings

D) To improve the shaft's flexibility

B) The weight of the shaft ensures that it maintains contact with the lower half of the bearing, making a full bush unnecessary in intermediate positions

C) To reduce the shaft's load on the bearing

7 / 10

Why does the aftmost bearing in a propulsion shaft system require a complete bush?

D) To decrease the amount of lubrication needed

C) To increase the flexibility of the bearing

B) To reduce the bearing's manufacturing cost

A) To provide full circumferential support and prevent any lateral movement, ensuring the shaft remains aligned as it exits the vessel

8 / 10

Which of the following best explains how a plain bearing system allows for longitudinal movement of the propulsion shaft?

C) By rigidly fixing the shaft to prevent movement

A) By using fixed bearings that do not allow any movement

B) By using axial clearances in the bearings that allow the shaft to slide back and forth slightly

D) By cooling the shaft to prevent expansion

9 / 10

Why is it important for the propulsion shaft to be able to move longitudinally within its plain bearings?

D) To reduce the overall weight of the propulsion system

C) To allow for easier alignment of the shaft

A) To increase the vessel's speed

B) To accommodate thermal expansion and contraction of the shaft, preventing excessive stress on both the shaft and bearings

10 / 10

What would be the consequence of not having a complete bush in the aftmost bearing?

A) Improved performance

C) Reduced friction

B) Increased risk of shaft misalignment and potential damage as the shaft exits the vessel

D) Enhanced shaft flexibility

Your score is