Epicyclic reduction gear, notably for turbomachine

An epicyclic reduction gear, or an epicyclic reduction gear for a turbomachine, comprising:

• an internal sun gear and an external sun gear, which are coaxial, with the internal sun gear being movable in rotation about its axis, with the external sun gear being stationary;
• at least one planet gear mounted to be movable in rotation on a planet carrier and meshing with both the internal sun gear and with the external sun gear, the planet carrier configured to pivot about the axis of the internal sun gear and the external sun gear, the planet gear including a cylindrical inner surface mounted to be movable in rotation around a cylindrical surface of the planet carrier;
• means for supplying oil to an interface between the cylindrical surfaces;
• wherein the oil supplying means comprises a chamber provided in the planet carrier, configured to form a buffer volume of oil, and including a lower zone spaced from the axis of rotation of the planet carrier, an upper zone closer to the axis of rotation of the planet carrier, at least one main passage opening at the interface and at the upper zone, and at least one secondary passage opening at the interface and at the lower zone,
• the secondary passage comprising a device configured to generate a pressure drop, obtained by stacking at least two elements, with each element comprising a fluid circulation passage configured to generate a pressure drop and comprising an inlet and an outlet, with the outlet, respectively the inlet of the passage of one of the elements being connected to the inlet, respectively to the outlet of the passage of the other element.