SBD plummer (pillow) block housings and THD take-up housings are intended 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 fillIf 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 70 to 80% of its volume.
At speeds above 1/3 of the bearing limiting speed, the values in table 1 for SBD housings and in table 2 for THD housings should be reduced by 20 to 30% to avoid high operating temperatures. For bearing limiting speeds, refer to the relevant product information.
For highly contaminated environments, use the SKF Three-Barrier Solution. In this case, check that the housing can accommodate SKF sealed self-aligning bearings. For additional information, contact the SKF application engineering service.
Grease quantities for an 80% fill are listed in table 1 for SBD housings and in table 2 for THD housings. The values are valid for a typical lithium grease (about 0,95 g/cm3) and include the grease for the bearing.
In most applications, the initial grease fill will adequately lubricate the bearing until the grease is exchanged during the next planned maintenance interval.
RelubricationSome high speed, high temperature or heavy load applications may require the bearing to be relubricated. SBD plummer block housings and THD take-up housings have a button head grease fitting to lubricate the bearing in accordance with DIN 3404. SBD housings have the grease fitting centred at the top of the housing body (fig. 1), while THD housings have the grease fitting centered on the side of the housing body (fig. 2).
The grease fitting can only be used to relubricate spherical roller bearings with a relubrication feature (a lubrication groove and holes in the outer ring). When applying grease via the relubrication feature, the shaft should be rotating.
CARB toroidal roller bearings should be relubricated from the side and not via the grease fitting. Therefore, CARB toroidal roller bearings need customized SBD and THD housings. For more information, contact the SKF application engineering service.