Roller-Element Ball Bearings and Their Applications

Roller-element bearings are the most commonly used and widely known types of bearing. The small ball bearings are used in the popular fidget spinner, cycle wheels, wheelchairs, etc. All types of ball bearings are used for the rolling purpose in which the object with wheels or rolling support is fitted with it in the axle of the wheel. There is a variety of ball bearings such as cylindrical bearings, spherical bearings, needle bearings, ball bearings, angular contact bearings and tapered bearings.

1) Needle Bearing

This is also a type of roller bearing which uses long cylindrical shaped rollers. They look like needles which is the reason that they are often referred to as needle bearings. Usually, the needles which are used as the rolling elements are four times longer than the diameter of the bearing. They are longer compared to the other roller-element bearings. 

This characteristic contributes to a bigger contact surface of the bearing which in turn benefits in a greater load-carrying capacity of both axial loads and radial loads. They are also used to greatly reduce the friction of the rolling object. One of the advantages of this type of bearing is that they are very thin even when having a larger surface area.

Application of Needle Bearing

• The rear-wheel vehicles use a minimum of seven to eight-needle bearings in the drive shaft.

• In automobiles, they are used in the components like compressors, rocker arm pivots, pumps and transmissions.

• They are used in planetary gear sets, power transmissions, gearboxes, and two-stroke and four-stroke engines.

2) Cylindrical Bearing

The cylindrical bearing is very similar to the needle bearing but the rolling elements are much more bulky and short in length which makes the whole bearing shorter than a needle bearing. As the rolling elements are more cylindrical than needle-like, they provide greater radial load support making it a suitable type of bearing to be used for high speed. 

As the common ball bearing has a single and multi-row bearing, cylindrical bearing also has single and double or multi-row bearings, in which the single-row cylindrical bearing is easy to assemble and disassemble whereas double or multi-row bearing provides a larger radial load-carrying capacity.

Application of Cylindrical Bearing-

3) Spherical Bearing

Self-aligning spherical bearings were used first by James Nasmyth during the 1840s for supporting line shaft bearings in mills. This type of bearing makes an angular rotation about a central point possible in two orthogonal directions. The rotation object or the shaft is fitted in the inner ring of the bearing which can be moved rotationally and also at an angle. 

The inner surface of the outer ring and the outer surface of the inner ring is spherical and connected, which allows the rotational and angular movement possible to a certain angle depending on the specification of the bearing.

Application of Spherical Bearing

4) Tapered Bearing

The tapered bearing is moreover in a conical shape where there are cylindrical rollers present as the rolling elements between the tapered inner and outer rings.

Application of Tapered Bearing

5) Angular Contact Bearings

This type of ball bearing has an outer and inner ringway which are displaced from each other that lie along the direction of the bearing axis. This ball bearing has the ability and is designed in a manner that can accommodate combined loads. 

Combined loads mean that axial and radial loads are acting simultaneously. The line joining the two points of contact in a ringway, along the radial plane is known as the contact angle. 

Applications of Angular Contact Ball Bearings

• The ideal usage purpose of angular contact ball bearings is for pumps, gearboxes, clutches and electric motors along with several other applications.

• Ball bearings are very commonly used in machine tools and material handling.

• Widely used in the field of wind energy and steel mill.

• As the angular contact ball bearings are famous for their high performance while supporting the combined loads of both axial and radial loads, they are used in the agricultural field due to the use of heavy machinery.

• This ball bearing type is used in automobiles because of their high reliability, sustainability and durability.

Conclusion

Most heavy machine companies and other manufacturing industries make use of these bearings regularly. Apart from such companies or organisations, bearings are not very commonly used in other industries. Selecting the most suitable bearing is very important and there are several features that should be considered before choosing one.