A mechanical reduction gear for a turbomachine, in particular for an aircraft, this reduction gear including a sun gear having an axis of rotation, a ring gear that extends around the sun gear, planet gears which are meshed with the sun gear and the ring gear, and a lubricating oil distributor which is configured to supply oil to the internal cavities of tubular supports of the planet gears, wherein each of the tubular supports includes a first angular sector including oil conveying pipes and a first outer peripheral surface for forming an oil film, and a second angular sector including a second outer peripheral surface in which a breaking tub of the oil film and recovering of the oil is formed.