Deep groove ball bearings are the most common type of rolling bearings. The basic type of deep groove ball bearing consists of an outer ring, an inner ring, a set of steel balls, and a set of retaining structures. 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 types. Open type refers to bearings without a sealed structure, while sealed deep groove balls are divided into dust-proof and oil proof seals. The dustproof sealing cover material is stamped steel plate, which only plays a simple role in preventing dust from entering the bearing raceway. The oil proof type is a contact type oil seal, which can effectively prevent the lubricating grease inside the bearing from overflowing.