滚珠轴承（Ball bearing）主要包含四个基本组件：滚珠（ball）、内环（inner ring）、外环（outer ring）与保持器（cage or retainer），如图所示。一般工业用的滚珠轴承满足AISI 52100的标准，滚珠与环通常是以高铬钢制成，洛氏硬度（Rockwell C- scale hardness）约在61-65之间。而保持器的硬度相较于滚珠与环低，其材料有金属（如：中碳钢、铝合金）或非金属（如：铁弗龙、PTEF、高分子材料）。由于滚动轴承（如右图）比颈轴承（journal bearing）的转动摩擦阻力小，因此相同的转速下，摩擦产生的温度会比较低。

A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races.

The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. It achieves this by using at least two races to contain the balls and transmit the loads through the balls. In most applications, one race is stationary and the other is attached to the rotating assembly (e.g., a hub or shaft). As one of the bearing races rotates it causes the balls to rotate as well. Because the balls are rolling they have a much lower coefficient of friction than if two flat surfaces were sliding against each other.