เกจวัดแรงดันเบนซิน , the European arm of Japanese bearing producer NSK, has developed deep groove ball bearings that don’t require external lubrication for use in submersible pumps handling cryogenic gases corresponding to hydrogen and LNG.
NSK has developed special shaft bearings with a cage produced from self-lubricating fluoroplastic for submersible pumps that deal with cryogenic gases and liquids.
The stainless-steel bearings with a cage made from self-lubricating fluoroplastic are seeing growing adoption in submersible pumps as a growing number of projects promote using hydrogen as an power source. These initiatives often use particular submersible pumps that can reliably pump gaseous and liquid media in continuous or intermittent operation at low temperatures right down to around -200°C.
In such pumps, the double bearing of the pump shaft is a crucial design factor. Corrosion resistance is important, and no lubricant can be utilized apart from the media washing around the bearing. However, this places powerful demands on the material pairing.
So NSK has developed a sequence of deep groove ball bearings particularly for these exceptional working conditions, and a quantity of other key design options provide differentiation from standard pump bearings. For instance, the internal and outer rings are manufactured from a stainless steel adapted to the particular necessities of rolling bearings.
A secure cage that occupies the whole inside quantity of the bearing offers guidance for the rolling elements (also made of stainless steel), while the cage material, a self-lubricating fluoroplastic, ensures low friction operating of the bearing with out exterior lubrication. In addition, the high-performance fluoroplastic is extremely wear-resistant and presents good low-temperature properties at speeds up to 3600 rpm. The cage has a two-piece design, with the two halves joined by stainless steel rivets.
The NSK bearings are available in numerous sizes (shaft diameter 30–100 mm) and are designed to be used in each bigger hydrogen pumping services and decentralised functions, similar to hydrogen filling stations.