Needle roller bearings

A needle roller bearing is a bearing which uses small cylindrical rollers . They are used to reduce friction  of a rotating surface.The typical structure consists of an inner race (or sometimes merely a shaft), a needle cage which orients and contains the needle rollers, the needle rollers themselves, and an outer race.Needle bearings are heavily used in engine components such as rocker arm pivots , pumps , compressors , and transmissions . The drive shaft  of a rear-wheel drive vehicle typically has at least 8 needle bearings and often more if it is particularly long, or operates on steep slopes .