NCCER Millwright Practice Exam

What type of bearing is most commonly used in rotational applications?

1. Ball bearing

2. Cylindrical bearing

3. Spherical bearing

4. Linear bearing

The correct answer is: Ball bearing

The most commonly used type of bearing in rotational applications is the ball bearing. Ball bearings are designed to reduce friction between moving parts by providing a smooth surface for rotation. They consist of an inner and outer race with small balls that fit between them, allowing for free movement in multiple directions. In rotational applications, the ability of ball bearings to handle both radial and axial loads makes them especially versatile. They are typically utilized in a wide range of machinery, including electric motors, pumps, and conveyor systems, due to their efficiency in minimizing wear and heat generation during operation. Ball bearings also have the advantage of being relatively easy to manufacture and maintain, contributing to their widespread use across various industries. This effectiveness and practicality in handling rotational forces make ball bearings the preferred choice compared to other types, which may be more specialized or limited in their application. For instance, cylindrical bearings are typically used where axial loads need to be supported, spherical bearings are best suited for applications requiring angular misalignment, and linear bearings are designed for linear motion rather than rotational movement.