Bearing cooling arrangement for air cycle machine

摘要

In air cycle machines with hydrodynamic bearings, the mass flow rate of coolant (36) passing through a series of bearings (32, 28, 30) is metered before the coolant passes through the final bearing (30). The final bearing operates at an internal pressure equivalent to that present in the region (72) into which coolant exhausts after exiting the final bearing. Since coolant in the final bearing is at the same pressure as air immediately downstream from the bearing, no rotating seal is required at the outlet of the bearing cooling flowpath.