Single source for specialist bearings
Original article date: June 2000
Need a specialist bearing, but don’t know where to turn? Tommy Miller looks at a new range that seems to fulfil most unusual needs
Specialist bearings have traditionally come from a variety of sources, depending on whether the need is for resistance to high temperatures, corrosive fluids, vacuum, super-clean conditions, nuclear, non-magnetic components or high speeds. But there is now a range, known as Spacea, that fulfils all of these needs. Indeed, this range covers not only ball bearings, but also linear guides and ballscrews.
Developed by NSK-RHP, the Spacea range includes products that utilise high performance materials and coatings, and specialist lubricants have also been introduced. For example, as well as hybrid bearings with steel races and ceramic balls, there are also all-ceramic bearings that can be used in corrosive environments, air or vacuum, at temperatures up to 200degC. For other applications under vacuum, it may be appropriate to use the products that have gold, silver, lead or molybdenum disulphide solid lubricants. If the need is for a bearing to operate under vacuum and at high temperatures (up to 500degC), silver is the preferred solid lubricant.
One of the new lubricants that has been developed by NSK is the LG2 grease that is suitable for clean-room use. Compared with fluorine greases, LG2 is claimed to provide 10 times the life as well as superior corrosion protection. Depending on the other conditions, it may be better to use fluororesin-coated bearings and ballscrews, perhaps if there is also a vacuum and high temperature – as might be found in production lines for liquid crystal displays.
Other coating and plating options available for the steel Spacea bearings include cold fluoride chrome plating for improved corrosion protection, hard chrome plating or nickel alloy coating. This latter coating is said to provide the highest level of resistance to corrosion and attack from most acids, but at a very reasonable cost.
Applications for the Spacea bearings, linear guides and ballscrews will, inevitably, be extremely wide-ranging due to the vast array of materials, finishes and lubricants that are included. Nevertheless, it is fair to say that they are likely to be used in aerospace, semiconductor processing, the nuclear industry, medical equipment and many more.
- NSK-RHP
June 2000