Shaft seal

The shaft seal (30) comprises an impeller side seal, which is provided between a bearing housing (31) and a shaft (20), and a bearing side seal, which is provided between the bearing housing and the shaft. An oil outlet chamber (53) is provided between the impeller side seal and the bearing side seal. The oil discharge chamber is limited by a third seal between the bearing housing and the shaft. A gas discharge chamber (55) is arranged between the third seal and the impeller side seal.