A roll stub is rotatable relative to a stationary support and has a rotatable support fixed to the roll stub, an annular and radially directed seal surface fixed on one of the supports, and a seal ring on the other of the supports having a lip engageable with the seal surface. A support element that is substantially less stiff than the seal ring is provided between the other support and the seal ring for biasing the lip against the seal surface while permitting of the seal ring relative to the other support. A clamp body rotationally fixed to the other support directly engages the seal ring and presses the seal ring directly against an abutment. Interengaging tooth formations on the clamp body and on the seal ring arrest the seal ring on the other support against angular movement thereon while permitting relative radial movement.