US Patent 7579725 Liquid cooled rotor assembly

A rotor assembly cooling system (100) and method of using same are provided. A portion of the rotor shaft (103) is hollow, the rotor shaft including an open end (107) and a closed end (105). A coolant feed tube (109) is rigidly attached to the rotor shaft (103) using one or more support members (111), thus causing the shaft and the feed tube to rotate at the same rate. Coolant is pumped through the feed tube until it exits the end of the feed tube and flows against the inside surface of the closed end of the rotor shaft causing the coolant to change direction and flow back through the coolant flow region, this region being defined as the space between the outer surface of the feed tube and the inner surface of the hollow rotor shaft.