Patent ID: 7544039
Filing Date: 2009-06-09
Classification: F01D,F02C

Abstract:
1. A concentric shaft and seal assembly, the assembly comprising: An inner shaft; An outer shaft concentric to the inner shaft; An outer shaft seal assembly forming a seal between the outer shaft and the assembly casing, the outer shaft seal assembly comprising a first outer shaft seal, a second outer shaft seal, a third outer shaft seal, and a fourth outer shaft seal; The first outer shaft seal and the second outer shaft seal forming a first outer shaft drain cavity, the second outer shaft seal and the third outer shaft seal forming an outer shaft purge cavity, and third outer shaft seal and the fourth outer shaft seal forming a second outer shaft drain cavity; An inner shaft seal assembly forming a seal between the outer shaft and the inner shaft and comprising a first inner shaft seal, a second inner shaft seal, a third inner shaft seal, and a fourth inner shaft seal; The first inner shaft seal and the second inner shaft seal forming a first inner shaft drain cavity, the second inner shaft seal and the third inner shaft seal forming an inner shaft purge cavity, and the third inner shaft seal and the fourth inner shaft seal forming a second inner shaft drain cavity; The assembly casing comprising a purge fluid passage in fluid communication with the outer shaft purge cavity, a first fluid drain passage in fluid communication with the first outer shaft drain cavity, and a second fluid drain passage in fluid communication with the second outer shaft drain cavity; and, Fluid communication means to fluidly communicate the first outer shaft drain cavity with the first inner shaft drain cavity, the outer shaft purge cavity with the inner shaft purge cavity, and the second outer shaft drain cavity with the second inner shaft drain cavity.