There are several different types of ball bearing suitable for many different applications. The most common types are single row deep groove ball bearings, double row deep groove ball bearings and angular contact ball bearings.
Single row deep groove ball bearings are probably the most common type of bearing in use, which is down to their versatility. They are simple in design, non-separable, suitable for high speeds, and are very robust in operation, requiring very little maintenance. Deep raceway grooves and the close conformity between the grooves and the balls enable deep groove ball bearings to accommodate axial loads in both directions, even at high speeds.
The most popular sizes of deep groove ball bearings are available either rubber sealed known as 2RS or metal shielded known as ZZ. This offers protection from the bearing being contaminated with dirt, but usually at the cost of a slower limiting speed.
Double-row deep groove ball bearings correspond in design to the single row variety, with common inside and outside diameters. However, having twin grooves to accommodate two rows of balls means that they are slightly wider. But they have a much greater load carrying capacity, and are therefore a preferred alternative to where a single row bearing would not be strong enough.
Angular contact ball bearings have raceways in the inner and outer rings that are displaced with respect to each other in the direction of the bearing axis. This means that they are designed to accommodate simultaneously acting radial and axial loads. The axial load carrying capacity increases with increasing contact angle. Like deep groove ball bearings, the angular contact bearing is available as a single or double row type.