Bearing News
16/09/2010
SJ Series Bearings offer greater durability and life in high temperature atmospheric and vacuum conditions up to 400°C.
NSK’s Spacea™ SJ series of high temperature bearings employ a solid MoS2 lubricant to provide outstanding levels of performance in normal atmospheric, high temperature and vacuum environments at temperatures up to 400°C. Manufactured from stainless steel and employing a patented ‘peapod’ structure that provides excellent torque stability and long life, the SJ bearings are designed for use in kilns, kiln cars, steel plants, vacuum vapour deposition equipment and high temperature conveyancing equipment.
The patented design of the SJ series bearings offers more than six times the durability of conventional bearings with solid lubricant paste, and also outperforms other solid lubricants in high temperature vaccum environments up to 10-8Pa: its solid spacer joints exhibiting minimal outgassing, easing pollution concerns.
The SJ design integrates a special cage pocket containing a solid lubricant spacer joint positioned between two specially treated balls. This arrangement, resembling a peapod, overcomes the problems of high temperature environments - as encountered in kilns, vacuum deposition equipment, and heat treatment conveyors, with the added benefits of extended maintenance-free performance and longer operating life.
The longer life performance of the SJ bearings is achieved via the steady supply of lubricant - a sintered molybdenum disulphide material, provided by the spacer joint. This ensures increased durability in high temperature atmospheric conditions. Also key to the SJ bearing’s groundbreaking levels of performance is a materials specification that includes Martensitic stainless steel for bearing inner and outer rings and balls (the latter can also be ceramic for added durability), and Austenitic stainless steel for the special pressed cages used in the bearings. In addition, the bearings can be protected against the ingress of contaminants with shields manufactured from Austenitic steel.
The balls used in the SJ series are one element in a two-part synergy designed to ensure excellent torque stability bearings over extended operating periods. They are coated with the same molybdenum disulphide material used for the spacer joints. This results in a symbiosis, in which both balls and spacer combine to achieve torque stability exceeding that of conventional silver coated bearings, even under demanding vacuum conditions.
NSK’s SPACEA™ RANGE: SPECIALLY DEVELOPED FOR DEMANDING APPLICATIONS
The SJ bearings are part of NSK’s SPACEA™ series, a unique range of bearings and lubricants that provides high performance and reliability under all types of demanding operating conditions: super-clean, vacuum, non- magnetic, corrosive, high/low temperature, nuclear and high speed.
SPACEA™ series bearings meet the widest range of technical requirements, with a programme of high performance materials, surface finishes and specially developed lubricants, including solid types. Depending upon the application, SPACEA™ bearings can be manufactured from Martensitic and Austenitic stainless steels for corrosive environments, ceramics, or a combination of both. Hybrid SPACEA™ types can have any combination of ceramic inner/outer rings or balls, however, the range also includes all ceramic bearings for use in highly corrosive and high temperature environments.