US Patent 10138942 Passive fault-tolerant shaft seal configuration

Disclosed herein is a shaft seal system comprising a first ball bearing, a second ball bearing, a primary shaft seal, and a secondary shaft seal. The secondary shaft seal may be inboard with respect to said primary shaft seal. The shaft seal system can define a leak chamber of a first diameter between said primary shaft seal and a secondary shaft seal. A plurality of O-rings may be further provided between an outer surface of said shaft seal system and said shaft system.