Which type of bearing utilizes balls to maintain separation between its races?

Ball bearings are designed specifically to use spherical balls to maintain separation between the inner and outer races. This design allows for smooth rotational motion with minimal friction, making them ideal for applications where precision and speed are important. The balls facilitate load distribution and are able to accommodate both radial and axial loads, enhancing the overall performance of the bearing.

In contrast, roller bearings use cylindrical rollers instead of balls, which provides a larger contact area and can support heavier loads but may also introduce more friction compared to ball bearings. Thrust bearings are designed specifically for axial loads, utilizing a different structure that often employs balls or rollers, but their primary function differs from that of standard ball bearings. Plain bearings, on the other hand, operate without rolling elements and rely on a smooth, flat surface, leading to higher friction levels compared to the rolling action provided by ball bearings. Therefore, ball bearings are uniquely defined by their use of balls to separate the races, optimizing their efficiency for various mechanical applications.