Deep groove ball bearing is most widely used. The race of both the inner and outer rings is shaped in circular-arc deep groove which can bear the diameter-oriented load, certain amount of double-way axis-oriented load, synthesized load and are good for speedy circumrotating. Deep groove ball bearing can be categorized into open bearings, bearings with single-sided seal, bearings with single-sided shield, bearings with double-sided seals, bearings with double-sided shields and bearings with stopping ring.