There are various types of aircraft bearings. In response to customers' requirements for bearings to reduce weight, minimize environmental pollution, and achieve high performance, the bearing systems have become more complex, demanding higher reliability and quality control. This also involves the design theory of the main shaft bearings of jet engines and the development trends of the industry. With the rapid development of emerging markets and the global expansion of low-cost airlines, the demand for and sales of commercial aircraft have been steadily increasing.