Rotating joint comprising pressurised sealing rings

Rotating joint for transferring a first fluid comprising:

• a male member and a female member mounted movably in relation to each other, the female member being a substantially hollow cylindrical element whose internal wall comprises a first annular cavity and a second cavity opening thereon, the second cavity being coaxial and contained in a substantially parallel plane distinct from that of the first cavity;
• a mechanical bearing to keep the male and female members concentric;
• an annular seal fitting into the first cavity, the seal having an upper contact surface and a lower contact surface with the first cavity, the contact surfaces being substantially normal to an axis of revolution of the rotating joint and cooperating solely with the first cavity, the male and female members being mutually arranged in order to form a toroidal chamber in which a first fluid passes at a pressure P1, the first cavity being located between the toroidal chamber and the second cavity;
• means for conveying a second pressurized fluid at a pressure P2 to the first cavity;
• means for conveying a third pressurized fluid at a pressure P3 to the second cavity;
• and
• a radial conduit located between the first and second cavities opening into the internal wall of the female member to convey a fourth fluid at a pressure Pi, so that the pressure P2 of the second fluid is equal to the pressure P1 of the chamber increased by a strictly positive determined pressure differential and the pressure P3 of the third fluid is equal to the pressure Pi of the fourth fluid increased by the same strictly positive determined pressure differential.