SKF support rollers without axial guidance are designed for applications where the associated components can be designed to provide axial guidance. The support rollers without inner ring are intended for arrangements where the pin or shaft can be hardened and ground.
The inner rings of SKF support rollers with inner ring are slightly extended to ensure the necessary axial play.
SKF support rollers of the (R)STO design
SKF support rollers of the (R)STO design are particularly simple in design. The support rollers with inner ring have the series designation STO, while those without inner ring are identified by the prefix R; the series designation being RSTO. All components of these SKF support rollers can be mounted separately.
SKF support rollers of the STO design can be used for applications where grease lubrication is employed as well as for oil-lubricated applications. Where oil is to be used, it is recommended that the grease contained in the roller on delivery is washed out first.
SKF support rollers without axial guidance, RSTO design
SKF support rollers of the (R)NA22.2RS design
SKF support rollers of the (R)NA22.2RS design are fitted with rubbing seals of oil and wearresistant nitrile rubber (NBR) which are suitable for operating temperatures between -30 and +120°C. They are designed for applications where particulate contamination is light to moderate and there is a possibility of moisture penetrating.
The SKF needle roller and cage assembly of the rollers is axially guided between two integral flanges in the outer ring and forms a non-separable unit with the outer ring. The inner ring of the NA22.2RS bearings can mounted separately. When the outer ring assembly and inner ring are joined, care must be taken not to damage the lips of the seals. Support rollers of series RNA22.2RS are without inner ring.