Red Seal Industrial Mechanic (Millwright) Practice Exam

What does 'shaft runout' measure in a mechanical system?

1. The amount of vibration in the shaft

2. The degree to which a shaft deviates from its true rotational axis

3. The length of the shaft itself

4. The temperature of the shaft during operation

The correct answer is: The degree to which a shaft deviates from its true rotational axis

Shaft runout measures the degree to which a shaft deviates from its true rotational axis. This deviation can result in uneven wear, increased vibration, and potential damage to bearings and other components within a mechanical system. Runout is often assessed using dial indicators, which highlight any misalignment or wobbling of the shaft as it rotates. Maintaining an acceptable level of runout is crucial for ensuring efficient operation and longevity of machinery, as excessive runout can lead to operational issues and failures. Thus, understanding and measuring shaft runout is essential for maintaining the integrity of rotating equipment.