Plain bearing for a planet gear of a mechanical reduction gear with silent operation

A plain bearing for a planet gear of a turbomachine mechanical reduction gear, the plain bearing having an annular barrel with an axis which delimits at least one central bore centred on the axis, and the barrel having annular grooves which extend around the axis and which open axially in opposite orientations at the axial ends of the barrel, each annular groove being delimited by two internal and external walls of the barrel connected by a transverse bottom wall which has at least one opening which opens into a cavity which is formed in the barrel between said at least one central bore and a periphery of the barrel,

• wherein each cavity is closed by a plug forming a sealing means which is received in the corresponding opening and at least partly in said cavity, and
• wherein each cavity is a cylindrical duct, in particular a drilling, which opens out via its opening into the bottom wall, and in that each plug comprises a cylindrical body which has a diameter corresponding to a diameter of said cylindrical duct and which is received in said duct.