How Bearings Work

There are many types of bearings, each used for different purposes. These include ball bearings, roller bearings, ball thrust bearings, roller thrust bearings and tapered roller thrust bearings.

Ball Bearings

Ball bearings, are probably the most common type of bearing. They are found in everything from inline skates tohard drives. These bearings can handle both radial and thrust loads, and are usually found in applications where the load is relatively small.

In a ball bearing, the load is transmitted from the outer race to the ball, and from the ball to the inner race. Since the ball is asphere, it only contacts the inner and outer race at a very small point, which helps it spin very smoothly. But it also means that there is not very much contact area holding that load, so if the bearing is overloaded, the balls can deform or squish, ruining the bearing.

Roller Bearings

Roller bearingslike the one illustrated below are used in applications like conveyer belt rollers, where they must hold heavy radial loads. In these bearings, the roller is acylinder, so the contact between the inner and outer race is not a point but a line. This spreads the load out over a larger area, allowing the bearing to handle much greater loads than a ball bearing. However, this type of bearing is not designed to handle much thrust loading.

A variation of this type of bearing, called aneedle bearing, uses cylinders with a very small diameter. This allows the bearing to fit into tight places.

Ball Thrust Bearing

Ball thrust bearingslike the one shown below are mostly used for low-speed applications and cannot handle much radial load. Barstools and Lazy Susan turntables use this type of bearing.

Roller Thrust Bearing

Roller thrust bearingslike the one illustrated below can support large thrust loads. They are often found in gearsets likecar transmissionsbetweengears, and between the housing and the rotating shafts. Thehelical gearsused in most transmissions have angled teeth -- this causes a thrust load that must be supported by a bearing.

Tapered Roller Bearings

Tapered roller bearingscan support large radial and large thrust loads.

圆锥滚子轴承用于汽车的枢纽,在哪儿e they are usually mounted in pairs facing opposite directions so that they can handle thrust in both directions.