NCCER Millwright Practice Exam

What does excessive wear in a bearing typically indicate?

1. Low lubrication

2. Improper alignment

3. High temperature

4. All of the above

The correct answer is: All of the above

Excessive wear in a bearing is a critical issue that often signals multiple underlying problems. Each of the factors—low lubrication, improper alignment, and high temperature—can contribute significantly to bearing wear and degradation. Low lubrication is essential for reducing friction between the moving parts of the bearing. Without sufficient lubrication, metal surfaces can come into direct contact, leading to increased wear and damage. Improper alignment is another factor that can cause excessive wear. When rollers or balls within the bearing are misaligned, it can lead to uneven distribution of loads and increased friction, thus accelerating wear. High temperature generally results from either insufficient lubrication or excessive operational speeds, leading to thermal degradation of the bearing materials. Elevated temperatures can weaken the lubricant, further reducing its effectiveness and contributing to wear. Because these factors are interconnected, experiencing one or more can lead to a cumulative effect of wear in the bearing, making "all of the above" the most comprehensive response to the question about excessive wear in a bearing. Understanding these relationships is crucial for diagnosing issues in millwright applications and ensuring the longevity of machinery.