SKF Combined needle roller bearings consist of a radial needle roller bearing combined with a thrust bearing and are consequently able to accommodate both radial and axial loads. Combined needle roller bearings provide the means to produce locating bearing arrangements where radial space is limited. They are particularly suitable for applications where other types of locating bearings occupy too much space, or where the axial loads are too heavy, the speeds are too high, or the lubricant is inadequate for simple thrust washers. SKF supplies combined needle roller bearings in the following designs:
- needle roller / angular contact ball bearings
- needle roller / thrust ball bearings
- needle roller / cylindrical roller thrust bearings
SKF Needle roller / angular contact ball bearings
Needle roller / angular contact ball bearings combine a radial needle roller bearing with a radial angular contact ball bearing to produce a low cross section bearing that can operate at high speeds and accommodate heavy radial and light axial loads. The radial loads are accommodated exclusively by the needle roller bearing. SKF supplies these bearings in the following two series:
NKIA series, accommodates axial loads in one direction
SKF needle roller / angular contact ball bearings in the NKIA 59 series can accommodate axial loads acting in one direction and can therefore locate the shaft in one direction.
For short shafts, where changes in length as a result of thermal expansion are relatively minor, two bearings in the NKIA 59 series can be used in a back-to-back (mirrored) arrangement
NKIB series, accommodates axial loads in both directions
SKF Needle roller / angular contact ball bearings in the NKIB 59 series are able to locate a shaft in both directions with an axial play between 0,08 and 0,25 mm. To facilitate mounting, the bearing has a two-piece inner ring. When mounting the inner ring, it is important that the two pieces are mounted immediately adjacent to each other without any gap between them.