NSK Europe, the European arm of Japanese bearing manufacturer NSK, has developed deep groove ball bearings that don’t require exterior lubrication for use in submersible pumps dealing with cryogenic gases corresponding to hydrogen and LNG.
NSK has developed particular shaft bearings with a cage created from self-lubricating fluoroplastic for submersible pumps that handle cryogenic gases and liquids.
The stainless-steel bearings with a cage made from self-lubricating fluoroplastic are seeing increasing adoption in submersible pumps as a growing number of initiatives promote the usage of hydrogen as an energy source. These initiatives often use particular submersible pumps that can reliably pump gaseous and liquid media in steady or intermittent operation at low temperatures right down to round -200°C.
In such pumps, the double bearing of the pump shaft is a critical design element. ไดอะแฟรม ซีล is important, and no lubricant can be utilized apart from the media washing across the bearing. However, this places robust demands on the fabric pairing.
So NSK has developed a series of deep groove ball bearings particularly for these distinctive operating situations, and several key design options present differentiation from typical pump bearings. For instance, the inner and outer rings are manufactured from a stainless-steel adapted to the special necessities of rolling bearings.
A stable cage that occupies the whole internal quantity of the bearing supplies steering for the rolling parts (also made from stainless steel), whereas the cage materials, a self-lubricating fluoroplastic, ensures low friction running of the bearing with out exterior lubrication. In addition, the high-performance fluoroplastic is extremely wear-resistant and offers good low-temperature properties at speeds as much as 3600 rpm. The cage has a two-piece design, with the two halves joined by stainless steel rivets.
The NSK bearings are available in varied sizes (shaft diameter 30–100 mm) and are designed for use in each bigger hydrogen pumping facilities and decentralised applications, such as hydrogen filling stations.