What is typically observed in the radial directions when a machine experiences parallel misalignment?

When a machine experiences parallel misalignment, the vibrations detected in the radial directions typically display moderate to high amplitude peaks primarily at 1x, and may also show peaks at 2x, 3x, and 4x. This occurrence is due to the nature of the misalignment creating additional harmonics in the vibration spectrum. Specifically, the fundamental frequency, identified as 1x, relates to the rotational speed of the rotor. In addition, misaligned machines often lead to higher harmonics due to the interaction of the misaligned components, which can create vibrations at multiples of the fundamental frequency.

This is in contrast to low amplitude peaks occurring at 1x only, which would not sufficiently represent the complexities introduced by parallel misalignment. A balanced spectrum with no significant peaks would indicate a well-aligned machine under normal operating conditions, and low amplitude peaks at 2x alone would not fully capture the potential range of frequencies generated by a misalignment scenario. The presence of 2x, 3x, and even 4x peaks alongside the fundamental frequency is indicative of the misalignment’s impact on machine operation and vibration profile, making the second choice the most accurate.