Patent ID: 7487848

Claim:
A top drive system for wellbore operations, the top drive system comprising motor apparatus, a main shaft having a top end and a bottom end, a seal ring around the main shaft, the seal ring having a primary seal surface and a secondary seal surface, a gear system driven by the motor apparatus and interconnected with the main shaft for driving the main shaft, bearing apparatus around the main shaft, the bearing apparatus containing bearing lubricant, a support member around the main shaft below the bearing apparatus, a sealing assembly below the support member and adjacent the main shaft for sealing against the main shaft to prevent the bearing lubricant from flowing down out of the bearing apparatus, the sealing assembly comprising a seal carrier adjacent the main shaft, a primary seal member on the seal carrier, the primary seal member sealingly contacting the primary seal surface of the seal ring, at least one secondary seal on the seal carrier, the seal carrier selectively movable to move the at least one secondary seal into sealing contact with the secondary seal surface of the seal ring, and the seal carrier releasably secured to the support member with at least one rotatable bolt threadedly mated with the support member so that rotating the at least one bolt moves the at least one secondary seal into sealing contact with the secondary surface to seal the ring.