DE2031608

A sealing structure for a system which rotates a driven coupling member in a contaminated compartment has a sleeve which extends into an opening of a wall of the cell defining the contaminated compartment and has an internal annular shoulder sealingly engaging an external shoulder of the driven coupling member in the compartment. The driven coupling member has an axial bore which is sealed from the contaminated compartment and can receive a torque-transmitting part of a second coupling member which is located without the compartment and is driven by a motor through the intermediary of a clutch. The sleeve is in sealing engagement with the wall, and the likelihood of leakage between the sleeve and the driven coupling member is further reduced by the provision of one or more packings, U-rings and/or liquid seals. The two shoulders bear against each other to prevent leakage of contaminating matter from the compartment when the second coupling is detached. The opening in the wall is evacuated prior to detechment of the second coupling member and remains evacuated until after attachment of a fresh second coupling member.