Abstract: The invention concerns a hydrodynamic retarder having a rotor which can be brought into rotation via a drive unit and a fixed stator or a stator rotating in opposite direction to the rotor, whereas the rotor and the stator comprise bladed wheels, which form together a working chamber which can be filled with working medium; the drive unit is provided with a separating clutch, by means of which the rotor can be disconnected for its immobilisation, comprising a driven primary side and a secondary side associated with the rotor; having a control device which controls the opening and closing of the separating clutch for switching the retarder (17).

Abstract: A motor vehicle drive train including a hydrodynamic retarder (1) that comprises a revolving bladed impeller (10) and a stationary or counter-rotating bladed turbine (11) which jointly form a working chamber (12) that can be filled with a working medium to switch on the retarder (1) is disclosed. The hydrodynamic retarder (1) can be mechanically disengaged from the drive train by a disconnect clutch (2). A fill level monitoring device (14) can detect the current fill level of the working medium in the working chamber (12), while a disconnect clutch-blocking device (9) is effectively connected in a communicating or mechanical manner to the fill level monitoring device (14) and prevents the disconnect clutch (2) from engaging in accordance with the detected fill level.

Abstract: The invention concerns a motor vehicle drive train, having a drive motor and drive wheels, whereas the drive wheels are driven by the drive motor via a main branch; having a hydrodynamic retarder, comprising a rotating rotor and a stator or a rotating rotor and a counter-rotor rotating in opposite direction to the rotor, which together form a working chamber which is filled or can be filled with a working medium; having a separating clutch, by means of which the rotor of the hydrodynamic retarder can be disengaged from a driving power flow in the drive train.

Abstract: There is provided a method for controlling a hydrodynamic retarder. The method includes determining a presence of a retarder switch-off request, and keeping a separating clutch closed, after the determining, for a preset time span and emptying a working chamber of the hydrodynamic retarder of a working medium by continuous actuation of a rotating bladed rotor and interruption of infeed of the working medium into the working chamber. The method further included varying the preset time span according to at least one of the following parameters or at least one parameter correlated with one of the following parameters: a rotational speed of the rotating bladed rotor, an output pressure, against which the working medium is emptied from the working chamber, a filling level of the working chamber with the working medium, a temperature of the working medium, and a braking torque of the hydrodynamic retarder.

Abstract: The invention relates to a motor vehicle drive train including a hydrodynamic retarder that comprises a revolving bladed impeller and a stationary or counter-rotating bladed turbine which jointly form a working chamber that can be filled with a working medium to switch on the retarder. The hydrodynamic retarder can be mechanically disengaged from the drive train by a disconnect clutch. The invention is characterized in that a fill level monitoring device detects the current fill level of the working medium in the working chamber, while a disconnect clutch-blocking device is effectively connected in a communicating or mechanical manner to the fill level monitoring device and prevents the disconnect clutch from engaging in accordance with the detected fill level.

Abstract: The invention relates to a hydrodynamic retarder comprising a rotor that revolves in a decelerating mode and a counter-rotating twin rotor or a stationary stator which jointly from a working chamber that is or can be filled with a working medium. The rotor can be driven using driving power via a drive train in order to decelerate the drive train. The invention is characterized in that an energy storage device is associated with or integrated into the retarder, said energy storage device comprising a mechanical energy store, pressure accumulator or kinetic energy store as well as an acceleration mechanism that is connected to the rotor, said acceleration mechanism being linked to the energy store and the rotor or being integrated into the rotor in order to convert energy stored in the energy store into an angular acceleration of the rotor.

Abstract: The invention concerns a hydrodynamic retarder having a rotor which can be brought into rotation via a drive unit and a fixed stator or a stator rotating in opposite direction to the rotor, whereas the rotor and the stator comprise bladed wheels, which form together a working chamber which can be filled with working medium; the drive unit is provided with a separating clutch, by means of which the rotor can be disconnected for its immobilisation, comprising a driven primary side and a secondary side associated with the rotor; having a control device which controls the opening and closing of the separating clutch for switching the retarder (17).

Abstract: The invention concerns a method for controlling a hydrodynamic retarder which can be disengaged mechanically via a separating clutch in a motor vehicle, which comprises a rotating bladed rotor and a bladed stator or a rotating bladed rotor and a bladed counter-rotor rotating in opposite direction thereto, which together form a working chamber filled with working medium in braking operation and emptied of working medium in non-braking operation, wherein the rotor is driven in braking operation via a drive train with a closed separating clutch and the working chamber is emptied when passing from the braking operation to the non-braking operation, wherein the transition from the braking operation to the non-braking operation is initiated via a retarder switch-off request of a driver assistance system or via actuation of an input device by the vehicle driver.

Abstract: The invention concerns a drive train having a hydrodynamic retarder, by means of which the drive train can be braked hydrodynamically; wherein the hydrodynamic retarder comprises a driven rotor and a stator or a driven rotor and a counter-rotor driven in reverse direction with respect to the rotor, which together form a working chamber which can be filled with working medium and which can be drained from said medium.

Abstract: The invention concerns a method for controlling a vehicle drive train with a hydrodynamic retarder which can be engaged and disengaged mechanically via a coupling, whereas the retarder comprises a working chamber formed between two bladed wheels, which is filled with a working fluid for generating a braking torque after detecting a retarder switch-on signal and is emptied of the working medium after detecting a retarder switch-off signal to turn off the braking torque, and the retarder is driven in braking mode by means of a drive shaft via the closed coupling to constitute a hydrodynamic circuit of the working fluid in the working chamber. The invention is characterised in that the speed of the vehicle and/or the rotational speed of the drive shaft is detected or calculated and the coupling is closed above a preset limit speed and/or above a preset limit rotation speed independent of the detection of a retarder switch-on signal to drive the retarder.

Abstract: The invention concerns a drive train, in particular of a motor vehicle fitted with a drive motor, including a main output shaft; having a transmission connected downstream of the drive motor in the drive power flow, comprising a transmission input shaft and a transmission housing; the transmission input shaft is connected to and actuated by the main output shaft of the drive motor or can be switched into such connection by means of a coupling; having a hydrodynamic retarder, comprising a driven bladed primary wheel and a stationary bladed secondary wheel or which is driven in reverse direction of the primary wheel, whereas both wheels form together a frusto-conical work space which is filled or can be filled with working medium, for hydrodynamic transmission of torque from the primary wheel to the secondary wheel; the drive motor includes an auxiliary output shaft, via which the primary wheel of the retarder is driven.

Abstract: The invention relates to a drive train, especially a motor vehicle with a drive engine, comprising a main output shaft, by means of which the drive wheels or any other unit can be driven; with a hydrodynamic retarder, comprising a driven bladed primary wheel and a bladed secondary wheel which is stationary or driven in opposite direction to the primary wheel, said wheels jointly forming a toroidal working chamber which is or can be filled with working medium in order to transfer torque hydrodynamically from the primary wheel to the secondary wheel; the drive motor comprises a power take-off shaft via which the primary wheel of the retarder is driven. The invention is characterized in that the hydrodynamic retarder is arranged as a single-step, uncontrolled retarder which can be switched exclusively between an activated state and a deactivated state.

Abstract: The invention relates to a method for operating a hydrodynamic retarder having at least one working chamber that is filled with a working medium in braking mode, and substantially emptied in non-braking mode. According to the invention, a prescribed amount of working medium is pulsingly brought into the working chamber of the retarder in non-braking mode. This can occur either constantly, or as a function of suitable measurement variables.