Abstract: A retarder having the following features: a rotor (1) and a stator (2) that, together, form a working space (3); a hollow shaft (4) for connecting, in a rotationally fixed manner, an input shaft (5), which is near a transmission, to an output shaft (6), which is near a cardan shaft, and; the hollow shaft support s the rotor by means of a screw thread (4.1.1).

Abstract: The invention relates to a retarder having the following features: a rotor (1) and a stator (2) that, together, form a working space (3); a hollow shaft (4) for connecting, in a rotationally fixed manner, an input shaft (5), which is near a transmission, to an output shaft (6), which is near a cardan shaft, and; the hollow shaft support s the rotor by means of a screw thread (4.1.1).

Abstract: A hydrodynamic braking system with a retarder including a rotor arranged in a rotor housing and a stator arranged in a stator housing, whereby the rotor and the stator together form a working space. The rotor is axially movable relative to the stator, from a first position (braking operating position) to a second position (non-braking operating position), and vice versa. The axial distance between the rotor and the stator in the non-braking operating position is a multiple of the distance separating them in the braking operating position. According to one aspect of the present invention the rotor housing includes an outlet that is located at a distance from the axis of rotation of the rotor and is open toward the rotor in the non-braking operating position such that the operating medium collected by the rotor is conveyed outside the working space through the outlet.