Designs and variants
The SKF range of deep groove ball bearings for high temperature applications provides solutions for various combinations of operating temperature and speed. All variants are lubricated for the life of the bearing, except for open VA201 bearings which require relubrication.
lists the lubrication type, maximum operating temperature, limiting speed, maintenance requirements and all other primary characteristics of the variants within the range.
High temperature deep groove ball bearings can be protected from contamination by either integrated shields, external shields or a combination of both.
For high temperature bearings, metallic shields are the primary recommendation when a capping device with low complexity is required. Shields prevent the ingress of solid contaminants into the bearing. They are non-contact, generate almost no friction and do not wear. Due to the material and design, they are particularly well suited for high temperatures.
High temperature deep groove ball bearings with designation suffix 2Z have integrated shields, but the VA201 variant is also available as an open bearing (fig. 1
). The shields on a 2Z/VA201 bearing enable the bearing to be filled with twice the amount of polyalkylene glycol/graphite lubricant that is used in an open VA201 bearing.
In many cases, the integrated shields are sufficient to keep contaminants out of the bearing. However, in some cases, the integrated shields are insufficient, and so additional external shields should be considered - either Nilos rings (fig. 2
), SKF sealing washers (fig. 3
) or custom made seals
For more information on sealing solutions, refer to Sealing solutions
Because of the large radial clearance for high temperature deep groove ball bearings, special attention should be given to the design of the sealing arrangement.
In cases where none of the sealing options above are applicable, SKF can provide custom made seals for operating temperatures up to 250 °C (480 °F). These seals are usually manufactured from PTFE (Polytetrafluoroethylene) thermoplastics.
PTFE coatings exposed to an open flame or temperatures above 300 °C (570 °F)
are a health and environmental hazard! They remain dangerous even after they have cooled.
Read and follow the safety precautions under Seal materials.
To further improve sealing systems that incorporate custom made seals, it is preferable to use a wear sleeve such as the SKF Speedi-Sleeve
. This improves the seal counter surface condition without the need for re-machining. Contact SKF for more information.