US Patent 11608785 Mechanical reduction gear of an aircraft turbomachine

A mechanical reduction gear of a turbomachine, in particular of an aircraft. The reduction gear includes a sun gear, a ring gear surrounded by a ring gear carrier, and planet gears meshed with the sun gear and the ring gear. The ring gear carrier includes an axial abutment on which the ring gear is configured to bear, and helical external splines which are engaged in complementary internal splines of the ring gear carrier and which are configured to cooperate by sliding with the internal splines so as to force the ring gear to be held against the abutment in operation.