NNF type bearings are double row full complement cylindrical roller bearings. Full complement cylindrical roller bearings (without a cage) incorporate a maximum number of rollers and are therefore suitable for very heavy radial loads at moderate speeds. They are used to locate the shaft axially in one direction and eventually to accommodate axial displacement of the shaft relative to the housing in the opposite direction.

NNF design bearings have a two-piece inner ring, held together by a retaining ring. The inner ring has three integral flanges and the outer ring has one integral central flange. The bearings are used to locate a shaft axially in both directions. The distance between the two rows of rollers enables these bearings to accommodate tilting moments. The outer ring of an NNF design bearing is little narrower than the inner ring. In applications with a rotating outer ring, it is no need for spacer rings between the inner ring and adjacent components. The outer ring has two snap ring grooves to simplify installation and save space axially, when the bearing is mounted in/on an adjacent component, e.g. in rope sheaves. The bearings have a contact PUR seal on both sides. Each seal is fitted in a recess on the inner ring shoulder. The seal lip exerts slight pressure against the outer ring raceway. The bearings are filled with a high-quality grease with good rust inhibiting properties. 

Application

The double row cylindrical roller bearings are usually used in industrial gearboxes, mechanical presses, electrical motors, pumps, compressors, steel mills, traction motors and axle boxes for railway vehicles and etc.