An impeller (230) for a planet carrier of a planetary gear speed reducer of a turbomachine, is configured intended to be rotatably secured to the planet carrier and to be rotated about an axis A of the speed reducer. The impeller has an annular shape about the axis and includes lubrication means (43, 45, 238), in particular for lubricating bearings of planet gears of the speed reducer. The lubrication means include an annular cavity (238) situated at the inner periphery of the impeller. The impeller includes an inner peripheral wall (246) closing the cavity (238) in the radial direction, and the impeller includes an annular port (248) that extends around the axis and that opens in the axial direction into the cavity in order to supply it with lubricating oil.