Misaligned couplings primarily cause which of the following issues?

• A. Increased fuel consumption
• B. Excessive vibration and bearing wear
• C. Lower insulation resistance
• D. Faster temperature rise in cooling water

Answer: (B)

Misalignment between coupled shafts sets up angular and offset errors that the coupling has to accommodate as the system rotates. Those errors translate into bending moments and lateral forces that are transmitted to the bearings and surrounding supports. The result is increased vibration, which becomes audible and measurable, and the bearings and seals experience uneven, higher loading. Over time this accelerates wear, fatigue, and potential failure of bearing surfaces and related components. While other issues like efficiency losses or cooling problems can occur for different reasons, the most direct and characteristic consequence of misaligned couplings is excessive vibration and bearing wear.