A gear apparatus (1) for a screw centrifuge, in particular a solid bowl screw centrifuge with a driven drum (23) and a screw (22) preferably driven at a speed difference relative to the drum (23), wherein the gear apparatus (1) is installed between at least one or more drive motors (24, 25) and the screw (22) and the drum (23) and wherein the gear apparatus (1) is continuously filled with an oil-type flowing lubricant, characterized in that a lubricant compensation system is provided for the gear apparatus, in particular a lubricant compensation circuit (5), comprising a lubricant compensation container (7) connected by way of a line (6) to at least one hollow channel of a drive shaft (9, 18) of the gear apparatus, said drive shaft designed as a hollow shaft.