A hydrodynamic machine comprising a housing, arranged within said housing: at least one shaft; a toroidal working chamber that can be filled with a working medium, the toroidal working chamber including a first housing with a first bladed wheel and a second housing with a second bladed wheel; a step-up gear arranged with the first bladed wheel about a common rotational axis and mounted such that they can rotate independently of one another; and a coupling device operable to transfer torque between the step-up gear and the first bladed wheel.