RETARDER FOR A MOTOR VEHICLE DRIVE TRAIN, AND MOTOR VEHICLE DRIVE TRAIN

The invention relates to a retarding brake device (16) for a motor vehicle drive train, comprising a retarder (17) whose drive shaft (20) is coupled to a first switching element (28), by means of which a connection of the drive shaft (20) to an output side of a motor vehicle transmission (2) can be established within the motor vehicle drive train. In order to be able to adapt operation of the retarder (17) to different driving conditions of a motor vehicle and at the same time to realize a high overall efficiency, the drive shaft (20) of the retarder (17) is moreover coupled to at least one further switching element (23), by means of which a connection of the drive shaft (20) to an output side (3) of a prime mover (1) upstream of the motor vehicle transmission (2) can be accomplished within the motor vehicle drive train.