NSK is redefining the operating parameters for high temperature
bearings with a new patent pending bearing design that provides
outstanding levels of performance in normal atmospheric and vacuum
environments at temperatures up to 400°C
The 'SJ' is the latest addition to NSK's Spacea bearings range. Key
design features include a special cage pocket containing a solid
lubricant spacer joint, positioned between two specially treated balls.
Resembling a peapod, this arrangement is capable of withstanding high
temperatures and contributes to an extended maintenance-free service
period and longer operating life.
Extended life is achieved thanks to the steady supply of lubricant (a
sintered molybdenum disulphide provided by the spacer joint). NSK claims
that it can be as much as six times longer compared with bearings that
use solid lubricant paste.
SJ bearings are constructed using a range of high-specification
materials, including martensitic stainless or bearing steel for the
bearing inner rings, outer rings and balls, and austenitic stainless or
cold-rolled steel for the special pressed cages. Ceramic balls are also
available where extra durability is sought.
The balls are coated with the same molybdenum disulphide material used
for the spacer joints. The balls and spacers thus combine to achieve a
torque stability exceeding that of conventional silver coated bearings,
even under demanding vacuum conditions.