Reduction gear for ring gear retention

A reduction gear for a turbomachine (6) extending around an axis (X-X) of rotation, comprising a ring gear (9) connected to a ring gear carrier (12), the ring gear carrier (12) extending between an internal shaft (122) which extends around the axis (X-X) of the ring gear (9),

• wherein
• the ring gear carrier (12) has, according to a section view along a plane including the axis (X-X), an internal segment (124), an external segment (126) and a ring gear support (128), extending successively from the internal shaft (122) until the ring gear support (128),
• the internal segment (124) extends until a radius R1 with respect to the axis (X-X),
• the external segment (126) forms an angle β with the internal segment (124),
• the ring gear support (128) forms an angle α with the external segment (126) and is secured to the ring gear (9) via a bolted connection accomplished at a nominal radius R2 with respect to the axis (X-X), characterized in that the ratio R1/R2 is comprised between 0.3 and 0.7, and in that the angle α is comprised between 60° and 85°, and the angle β is comprised between 150° and 175°.