TRANSFORMER oil pump bearings in ÖBB’s 332 Class 1016 and 1116 Taurus locomotives are being replaced with non-conducting hybrid bearings from NKE.
Simultaneous operation of the auxiliary converter and transformer cooling oil pumps as the locos started up was causing excessive current flow in the bearings. In consultation with NKE, ÖBB decided to install angular contact and deep groove ball bearings made from ceramic oxide, providing complete electrical isolation.
NKE can also supply bearings which have an oxide layer applied to the outer race through thin-film plasma spraying, giving a dielectric strength of at least 1 kV DC or AC.
NKE Bearings, Austria