Roller Bearing vs Ball Bearing
A bearing is a device that is used in between two moving or rotating surfaces to facilitate smooth movement and to reduce friction. Bearings have a long history and even before the modern types of bearings came into existence, man used different objects that helped in transportation of large, heavy objects reducing friction. Bearings are classified depending upon their shapes and sizes and also according to motions they allow and their load bearing capacities. There are many types of bearings but the most common are roller bearings and ball bearings. There are many differences between these two types of bearings that will be discussed in this article.
Anyone using a bicycle or roller skates must have noticed the presence of ball bearings that make the motion of the wheels in these two devices very smooth. Bearings help moving parts rotate for long reducing friction. Most mechanical devices make use of one or the other type of bearings for their spinning parts. Though both roller and ball bearings serve the same basic purpose; their differences lie in their design and load bearing capacities.
Ball bearings make use of hardened spherical balls that can handle both radial as well as thrust loads. They are made use of where the load is relatively small. In the case of ball bearings, the load is transmitted from the outer race to the balls and then from the balls to the inner race. Because the bearings are spherical, there is very small area of contact with the load. Thus when the load is high, the balls may get deformed ruining the bearing.
Roller bearings are used in applications where large load is to be borne, for example in conveyor belts where rollers must bear heavy radial loads. As the name implies, the roller is not a sphere but cylindrical in shape so that contact between the outer and inner race is not a point but a straight line. Thus there is a greater contact than ball bearings and the load is spread out over a larger area allowing roller bearings to bear a much heavier load than ball bearings. One variation of roller bearings is known as needle bearings where the diameter of the cylinders is very small.
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Roller Bearing vs Ball Bearing • Once we know the function and purpose of bearings, it is easy to make changes in shapes and designs for use in various circumstances. This is why ball bearings and roller bearings are used in different applications. • In the case of ball bearings, the bearings are hardened spherical balls that greatly reduce the friction between moving parts but since the area of contact is a point only, they do not have a great capacity to bear loads. • On the other hand in the case of roller bearings, the area of contact is a line rather than a point thus distributing the load over a larger area. They have a very high capacity to bear loads.
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