A planetary gear device for a turbomachine includes a planetary carrier and planetary wheel arranged in an axial direction between two planetary carrier areas connected to a support appliance, with the planetary wheel rotatably mounted on the support appliance. On outer sides facing away from the planetary wheel, the planetary carrier areas include cone surfaces that enclose connection areas with the support appliance, with diameters decreasing with increasing axial distance from the planetary wheel. Cone surfaces of a tensioning appliance radially enclose and are respectively adjusted thereto and act together such that a force that respectively results from an axial tensioning force of the tensioning appliance applied on the cone surfaces of the planetary carrier areas is applied at the connection areas between the support appliance and the planetary carrier areas. The tensioning appliance cone surfaces operatively connect via a coupling element.