US Patent 7416344 Pump carrying supercritical fluid with ceramic bearings

A pump for carrying supercritical CO2 fluid or liquid CO2 capable of securing reliability by optimizing a bearing part. An angular ball bearing (8) comprises an inner ring (8a), an outer ring (8b), balls (8c) held therebetween, and a cage (8d) holding the balls (8c). Both the balls and the inner and outer rings are formed of a ceramic to form a totally ceramic bearing. Also, the cage (8d) is guided by the outer ring or the inner ring. Specifically, for example, when the cage is guided by the inner ring, the inner peripheral surface (8db) of the cage (8d) opposed to the outermost peripheral surface (8ab) of the inner ring (8a) is guided by the outermost peripheral surface (8ab) of the inner ring (8a).