The energy recovery system is designed such that the waste heat of a combustion engine (10) is converted into mechanical energy. A connection assembly (13) is provided, through which the mechanical energy is generated by the energy recovery system is launched into the mechanical energy generated by the combustion engine. The connection assembly has a gear mechanism, through which an output shaft (12) of the energy recovery system is connected with an output shaft (11) of the combustion engine. Independent claims are included for the following: (1) a traveling working machine or vehicle; and (2) a method for operating an energy recovery system.
