The two major types of misalignment that are corrected by shaft alignment are __________.

• A. angular and parallel
• B. radial and axial
• C. vertical and horizontal
• D. torsional and lateral

Answer: (A)

The main idea is that shaft alignment targets two common misalignment forms: angular misalignment and parallel (offset) misalignment.

Angular misalignment happens when the two shaft axes aren’t in a straight line and meet at an angle. This creates varying loading as the shafts rotate, leading to vibration and uneven wear. Parallel misalignment, also called offset, occurs when the shafts run parallel but their centerlines are offset, so the coupling experiences a side load that stresses bearings and seals.

Shaft alignment aims to bring the shafts into proper alignment so their axes are colinear and parallel, eliminating the loads that cause vibration, wear, and leaks. The other terms listed aren’t the standard categories used in shaft alignment; they don’t describe the common ways shafts can be misaligned in practice.