Patent ID: 6962341

Claim:
A coupling for supplying a heat-exchange fluid to a load rotatable about an axis, the coupling comprising: a shaft fixed to and extending from the load, having an end opening, and centered on the axis; a nonrotating housing surrounding the shaft at the end opening; means connected to the housing for pumping the heat-exchange fluid through the housing, opening, and shaft into the load; a roller bearing engaged between the housing and the shaft axially between the opening and the load, whereby the shaft can rotate freely in the housing about the axis; respective seal rings rotationally fixed on and sealed to the housing and the shaft between the bearing and the opening and bearing axially on one another, the seal rings sliding on one another on rotation of the load and forming an inner chamber with the shaft and an outer chamber outside the inner chamber and separated by the seal rings from the inner chamber; a cooling sleeve on the housing surrounding and extending axially past the seal rings; means for cooling the cooling sleeve; and an insulator having a part closely radially surrounding the shaft between the seal rings and the opening and forming with the shaft a small gap through which the heat-exchange fluid can flow into the outer chamber, the seal rings being exposed in the outer chamber to the fluid flowing through the gap and substantially blocking this fluid from getting to the inner chamber and bearings.