Turbine comprising a ventilation system between rotor and stator

A turbine comprising:

• two bodies rotating with respect to one another,
• a ventilation chamber defined by the bodies and comprising at least one opening for purge to a jet of the turbine at a first side of the chamber and a second opening, occupied by a first sealing joint having a leak flow rate, disposed between the bodies at a second side of the chamber and leading to an enclosure with respect to which the chamber is at overpressure,
• a ventilation circuit present in a first of the bodies, extending up to a partition separating the ventilation circuit from the chamber, and leading to the chamber via a first injection orifice passing through the partition,
• a second injection orifice passing through the partition, and through which the ventilation circuit leads to an antechamber defined by portions of the bodies and having an antechamber opening occupied by a second sealing joint having a leak flow rate, said antechamber opening leading exclusively to the chamber,
• wherein the first sealing joint and the second sealing joint are labyrinth seals that have elements responsible for the sealing, comprising circular rigid fins and abradable pads extending in front of edges of the fins, that are carried by portions of the bodies all oriented in the same direction.