Turbomachine with counter-rotating fan

The turbomachine has a front fan shaft (34) which is connected to an upstream end (24a) of a low-pressure shaft (24) by utilizing a dismountable torque transmission sleeve (48). The sleeve and the shaft form an oil supply cavity (62) for lubricating and cooling antifriction bearings (44, 46) that are mounted between the shaft (34) and a rear fan shaft (38) connected to an upstream end of a low-pressure shaft (26).