FNL flanged housings are designed for grease lubrication. The lubricant should be selected based on the operating conditions of the bearing. For additional information, refer to Lubricant selection.
Initial grease fill
If no other requirements exist, the free space in the bearing should be completely filled with grease and the free space in the housing should be filled to 20 to 40% of its volume. A 40% grease fill is required when bearings have to be relubricated from the side, while a 20% grease fill is used when bearings are relubricated via the outer ring.
For highly contaminated environments and slow speeds, fill the housing to 70–80%. For additional information, contact the SKF application engineering service.
In most applications, the initial grease fill will adequately lubricate the bearing until the grease is exchanged during the next planned maintenance interval.
Certain operating conditions such as high speeds, high temperatures or heavy loads may require relubrication. Therefore FNL housings have two holes that have been drilled and tapped for an AH 1/8-27 PTF grease fitting (fig. 1).
Relubrication via the outer ringThe hole closest to the cover should be used to relubricate spherical roller bearings with a relubrication feature (a lubrication groove and holes in the outer ring) (fig. 2). When applying grease via the relubrication feature the shaft should be rotating.
Relubrication from the side
When relubricating from the side, which is typically necessary for self-aligning ball bearings and CARB toroidal roller bearings, the hole closest to the flange should be used (fig. 3).