Cryogen transfer coupling with adjustable throttle valve for rotating machinery

In a dynamoelectric machine having a rotor member disposed upon a shaft for rotation within an annular stator member, said shaft having a passage for permitting the flow of a cooling fluid therethrough to said rotor member, coupling means secured to said shaft for transferring said cooling fluid from a reservoir to said shaft passage, said coupling means having a first conduit portion connected to the reservoir defining an inlet flow path and a second conduit portion connected to said shaft defining a discharge flow path for said cooling fluid, the inlet flow path being in fluid communication with the reservoir and the discharge flow path being in fluid communication with said shaft passage, said first and second conduit portions being interconnected in an overlapping, radially spaced apart relation by rotatable interconnecting means to define a relative motion gap between the overlapping conduit portions and to permit rotational movement of said second conduit portion relative to said first conduit portion, the combination with said coupling means of an adjustable throttle valve for regulating the flow of cooling fluid passing therethrough, said throttle valve comprising a valve seat disposed within the discharge flow path of said second conduit portion and providing a fluid passageway therethrough, a valve plug disposed within said discharge flow path of said second conduit portion having seating surfaces which cooperate with said valve seat to throttle the flow of cooling fluid therethrough, said valve plug having a stem portion disposed within and extending axially through said first conduit portion for supporting said valve plug, means connected to said stem for axially displacing said stem and valve plug relative to said valve seat, and means for fluidly sealing said relative motion gap from the atmosphere.