They cover a wide dimensional range, have the radial part with full complement of rollers, but another version does exist , for high speeds, with a reduced dimensional range and guided and spaced cylindrical rollers with radial cage, mounted in an outer ring that also functions as a central washer for the axial group, in order to make it absorb bidirectional axial stresses, assisted in this by two axial roller / needle cages and by lateral washers spaced apart by an inner ring which generally forms a whole with one of the two washers. Outer, inner ring and washers are flanged to allow assembly and eventual adjustment of the rolling unit; they have high precision and rigidity and withstand loads and tilting moments of considerable intensity, they are supplied pre-lubricated with grease and can be relubricated through an adequate drilling of the outer and inner ring.
Large precision bearings can be divided into:
precision angular contact ball bearings
large four-point contact ball bearings
precision thrust roller bearings
ball bearings for screw drives