Abstract: A seal arrangement located between a lubricated chamber and a pressurized chamber pressurized by a gas at a variable pressure. The seal arrangement includes a seal around a shaft extending into the lubricated and pressurized chambers through a wall separating the chambers. The seal slides along the shaft between a first and a second abutment position via a variable pressure exerting a force on an end face, i.e., a casing, of the seal. The casing, the shaft and seal define a clearance allowing air to pass from the pressurized chamber to the lubricated chamber. Springs urge the seal toward the first abutment position against the variable pressure and have a strength so that, when the variable pressure is under a predetermined value, the clearance is sealed. When the variable pressure is over a predetermined value, the seal slides to the second abutment position and the clearance is opened to allow the pressurized gas to flow from the pressurized chamber to the lubricated chamber.