By using these bearings, housings can be easily designed for mounting. Pressed steel cages are generally used in deep groove ball bearings. However, machined cages are also manufactured for the larger sized bearings used for high speed operation. Shielded ball bearings S hielded ball bearings have the same boundary dimensions as those of open type bearings. The shields protect against the penetration of foreign material and the prevention of grease leakage.
T here are two types.
One is type ZZ fitted with shield plates on both sides and the other is type Z fitted with a plate on one side. Since the shields are non-contact type, friction torque is very low. L ike shielded bearings, sealed ball bearings have the same boundary dimensions as those of the open type. Sealed ball bearings also keep foreign matter out and grease in. S eals consist of synthetic rubber molded to a steel plate.