Rollers are classified into four types; tapered, cylindrical, spherical, and needle bearings. The needle bearings are the smallest and lightest in the bearing family. These needle bearings use long, thin, and cylindrical rollers that look like needles. In common roller bearing designs, the rollers are only slightly longer than their diameters. However, the needle bearings
have their rollers designed at least four times longer than their diameter. Because of the elongated roller design, needle bearings offer a wider contact surface area with races to help reduce friction. Besides, the large surface area also helps to support a greater load. Today, they have become very common because they need less clearance between the surrounding structure and the axle. They are also affordable. The needle bearings are largely used in vehicle parts such as compressors, transmissions, pumps
, pivots, and rocker arms. In the drive shaft of every vehicle's real-wheel, you will get at least one needle bearing.