🔍 Key Concepts

• Flexible coupling alignment and what figure 4 is showing about the relative positions of the motor and compressor shafts • Difference between radial bearing load from misalignment and axial thrust along a crankshaft • Which machine in figure 4 is actually tilted/misaligned, and which one remains level on its base

💭 Think About

• Look closely at figure 3, then at figure 4. Which unit’s shaft centerline has moved relative to the reference straightedge, the motor or the compressor? What does that do to the forces transmitted through the coupling? • Ask yourself whether an angular vertical misalignment between two coupled shafts is more likely to increase side (radial) loading on bearings or true end‑to‑end (axial) thrust along the crankshaft. • Between the motor and the compressor, which set of bearings is generally more sensitive to extra bending and side loads from misalignment of the coupling?

✅ Before You Answer

• Verify from the illustration which component is out of level in figure 4 compared to figure 3. • Decide whether the main effect of this condition is radial/bending load on bearings or a change in axial thrust along the shaft. • Match that effect to the option that best describes which machine’s bearings would most likely experience premature damage under these conditions.