Deep groove ball bearings are the most common type of rolling bearings. The basic deep groove ball bearing consists of an outer ring, an inner ring, a set of steel balls, and a retaining structure. There are two types of deep groove ball bearings: single row and double row. The deep groove ball structure is also divided into sealed and open structures. Open refers to the bearing without a sealed structure, while sealed deep groove balls are divided into dustproof seals and oil proof seals.