# US 2014/0151176 A1 · Method for Controlling a Hydrodynamic Retarder which can be Disengaged Mechanically Via a Separating Clutch > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0151176 A1 - Document ID: US20140151176A1 - Status: Published application - Kind: A1 - Application number: 13/883,983 - Filed: 2012-11-28 - Published: 2014-06-05 - Earliest claimed: 2011-12-09 - Assignees: Voith Patent GmbH - Applicants: Voith Patent GmbH - Inventors: Achim Menne; Tilman Huth; Dieter Laukemann; Werner Koch; Werner Klement; Martin Becke - Web page: https://patentgrep.com/patent/US20140151176A1 ## CPC - F16H 41/24: Details - B60T 10/02: with hydrodynamic brake - F16D 57/04: with blades causing a directed flow, e.g. Föttinger type - F16D 67/02: Clutch-brake combinations - F16H: GEARING - B60T: VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL (electrodynamic brake systems for vehicle, in general B60L; brakes per se, i.e. devices where braking effect occurs, including ultimate brake actuators, F16D); ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES ## 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. The invention is characterised in that after determining the presence of a retarder switch-off request the separating clutch is kept closed for a preset time span and the working chamber of the retarder is emptied of the working medium by continuous actuation of the rotor and interruption of infeed of working medium into the working chamber, wherein the preset time span is varied according to at least one of the following parameters or at least one parameter correlated with one of the parameters and/or after determining the retarder switch-off request: the rotational speed of the rotor; an output pressure, against which the working medium is emptied from the working chamber; the filling level of the working chamber with working medium; the temperature of the working medium; the braking torque of the hydrodynamic retarder. ## Claims ### Claim at position 1 1-8. (canceled) ### Claim 9 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 and the separating clutch opens, 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; wherein: after determining the presence of a retarder switch-off request the separating clutch is kept closed for a preset time span and the working chamber of the retarder is emptied of the working medium by continuous actuation of the rotor and interruption of infeed of working medium into the working chamber, wherein the preset time span is varied according to at least one of the following parameters or at least one parameter correlated with one of the parameters and/or after determining the retarder switch-off request: the rotational speed of the rotor; an output pressure, against which the working medium is emptied from the working chamber; the filling level of the working chamber with working medium; the temperature of the working medium; the braking torque of the hydrodynamic retarder. ### Claim 10 (depends on 9) The method according to claim 9, wherein the preset time span is increased as the rotational speed decreases. ### Claim 11 (depends on 9) The method according to claim 9, wherein the preset time span is increased as the outlet pressure increases. ### Claim 12 (depends on 10) The method according to claim 10, wherein the preset time span is increased as the outlet pressure increases. ### Claim 13 (depends on 9) The method according to claim 9, wherein the preset time span is increased as the filling level increases. ### Claim 14 (depends on 10) The method according to claim 10, wherein the preset time span is increased as the filling level increases. ### Claim 15 (depends on 11) The method according to claim 11, wherein the preset time span is increased as the filling level increases. ### Claim 16 (depends on 9) The method according to claim 9, wherein the preset time span is decreased as the temperature increases. ### Claim 17 (depends on 9) The method according to claim 9, wherein at the preset time span is increased as the braking torque increases. ### Claim 18 (depends on 9) A hydrodynamic retarder having a rotating bladed rotor and a bladed stator or a rotating bladed rotor and a counter-rotor rotating in opposite direction thereto, which together form a working chamber which can be filled with working medium in a braking operation and which can be emptied of working medium in a non-braking operation, having a drive train, by which the rotor is driven and in which a separating clutch is provided, whereas a retarder control device is associated with the hydrodynamic retarder, wherein the retarder control device is arranged to carry out the method according to claim 9. ### Claim 19 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 counter-rotor is driven in braking operation via a drive train with a closed separating clutch or the stator is supported stationary against a fixed component in braking operation with a closed separating clutch and the working chamber is emptied when passing from braking operation to non-braking operation and the separating clutch opens, 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; wherein: after determining the presence of a retarder switch-off request the separating clutch is kept closed for a preset time span and the working chamber of the retarder is emptied of the working medium by continuous actuation of the rotor and interruption of infeed of working medium into the working chamber, wherein the preset time span is varied according to at least one of the following parameters or at least one parameter correlated with one of the parameters and/or after determining the retarder switch-off request: the rotational speed of the rotor; an output pressure, against which the working medium is emptied from the working chamber; the filling level of the working chamber with working medium; the temperature of the working medium; the braking torque of the hydrodynamic retarder. ### Claim 20 (depends on 19) The method according to claim 19, wherein the preset time span is increased as the rotational speed decreases. ### Claim 21 (depends on 19) The method according to claim 19, wherein the preset time span is increased as the outlet pressure increases. ### Claim 22 (depends on 20) The method according to claim 20, wherein the preset time span is increased as the outlet pressure increases. ### Claim 23 (depends on 19) The method according to claim 19, wherein the preset time span is increased as the filling level increases. ### Claim 24 (depends on 20) The method according to claim 20, wherein the preset time span is increased as the filling level increases. ### Claim 25 (depends on 21) The method according to claim 21, wherein the preset time span is increased as the filling level increases. ### Claim 26 (depends on 19) The method according to claim 19, wherein the preset time span is decreased as the temperature increases. ### Claim 27 (depends on 19) The method according to claim 19, wherein at the preset time span is increased as the braking torque increases. ### Claim 28 (depends on 19) A hydrodynamic retarder having a rotating bladed rotor and a bladed stator or a rotating bladed rotor and a counter-rotor rotating in opposite direction thereto, which together form a working chamber which can be filled with working medium in a braking operation and which can be emptied of working medium in a non-braking operation, having a drive train, by which the rotor is driven and in which a separating clutch is provided, whereas a retarder control device is associated with the hydrodynamic retarder, wherein the retarder control device is arranged to carry out the method according to claim 19.