Needle roller bearings are a type of roller bearing with slender cylindrical rollers. The diameter of the rollers is no more than 5mm, and the length is more than 2.5 times the diameter. This type of bearing has a compact structure and is particularly suitable for situations where the radial installation size is limited, capable of withstanding high radial loads. It is widely used in automotive engines, transmissions and industrial machinery, featuring low friction and high rotational speed. When installing, attention should be paid to the correct fit of the cage assembly.