🔍 Key Concepts

• Identify on the illustration which side is the astern thrust element and how thrust is transmitted when the shaft is turning astern. • Notice which parts (adjusting ring vs filler piece) control the axial position of the thrust elements relative to the thrust collar. • Think about basic machine geometry: when you increase or decrease the thickness of a spacer, what happens to the clearance between the two faces it separates?

💭 Think About

• Trace the load path for astern thrust from the thrust collar, through the thrust element, into the casing. Which component’s thickness change would move the astern thrust element closer to the collar? • Look at whether the adjusting ring or the filler piece is between the astern thrust element and the stationary housing. If that part gets thicker, does the element move toward or away from the collar? • Compare the effect of changing the adjusting ring versus the filler piece: which one actually alters the running clearance, and which one mainly just fills space for bolting/cover fit?

✅ Before You Answer

• Be sure you have clearly identified the astern side versus the ahead side of the thrust bearing on the drawing. • Confirm which component lies directly behind the astern thrust element in the axial direction; that is the one that will change the oil clearance when its thickness is altered. • Mentally ‘slide’ the thrust element as that backing piece gets thicker or thinner and verify whether the clearance to the collar decreases (moves closer) or increases (moves away).