Four-Row Cylindrical Roller Bearings
Four-row and multi-row cylindrical roller bearings are used almost exclusively for the roll necks of rolling mill stands, calenders and roller presses. Their friction is low compared with other roller bearings. As they are normally mounted with an interference fit on the roll neck, they are particularly suitable for rolling mill applications where the rolling speed is high.
Multi-row cylindrical roller bearings are only able to accommodate radial loads. They are therefore mounted together with deep groove or angular contact ball bearings, or with tapered roller bearings, either radial or thrust designs, which take up the axial loads.
The four-row and multi-row cylindrical roller bearings are separable, the rings with integral flanges and rollers and cage assemblies could be separated with inner rings. Therefore it is convenient to wash, check, mount and dismount. A certain limited axial displacement of the shaft with respect to the housing can be accommodated within the bearing.
Bearings of type FC consist of two outer rings with rollers and cage assemblies and a flangeless inner ring.
Bearings of type FCD consist of two bearing of type NN. Type FC and FCD can not limit axial displacement between shaft and housing, therefore they are suitable to be used as non-locating bearings. Normally, their cages are made from solid machinery.