🔍 Key Concepts

• Thermal expansion of metal components in rotating machinery as temperature increases • How tapered roller bearings locate a shaft axially (they can carry both radial and axial loads) • Meaning of a designed-in end clearance at assembly versus what happens at operating temperature

💭 Think About

• When the compressor starts cold and then reaches normal operating temperature, what happens to the length of the crankshaft and the bearing housings? • If tapered roller bearings can carry axial (thrust) load, why might an engineer deliberately leave some axial clearance at the start? • Which option best matches a change that will occur specifically as the unit warms up, rather than a dynamic running condition like vibration or web deflection?

✅ Before You Answer

• Identify which choices describe a temperature‑related, gradual change versus a dynamic running condition (like vibration or deflection). • Recall that tapered roller bearings, when preloaded too tightly, can overheat and fail as parts expand—how does end clearance help avoid this? • Eliminate any options that do not logically involve change in length or position along the crankshaft’s axis as temperature rises.