🔍 Key Concepts

• Role of a thrust bearing in a turbine (what motion it controls) • Difference between axial movement (endwise) and radial movement (up‑and‑down/sideways) of a rotor • Which turbine measurements directly indicate end thrust and wear on thrust pads or shoes

💭 Think About

• Ask yourself: When a thrust bearing wears, what changes physically about the rotor’s position inside the casing? • Which of these choices is a direct indication of endwise (axial) shift of the rotor rather than thermal growth or overall casing movement? • Which parameter would be routinely recorded in a log to confirm that the thrust bearing is holding the rotor in its correct fore‑and‑aft position?

✅ Before You Answer

• Identify which choice directly tracks axial position of the rotor, not temperature or expansion rate. • Eliminate any answers that mainly reflect thermal expansion of metal parts rather than bearing wear. • Focus on the option that would change if the rotor were slowly creeping forward or aft due to thrust bearing wear.