Patent application number | Description | Published |
20080217134 | Process for pressure actuation of a shifting element - The invention concerns a process for pressure actuation of a rotating shifting element of an automatic transmission or automated manual transmission, in which the shifting element is configured with a piston that interacts with a torque transfer element and a pressure medium supply, by way of which the piston can be actuated with pressure medium in order to be displaced into a positioned defined for an activated state of the shifting element, and in which a pressure pulse can be induced in the pressure medium supply in a de-activated state of the shifting element. It is proposed that the pressure medium pulse be triggered when the pressure medium amount drained from the de-activated shifting element has reached a predefined value. | 09-11-2008 |
20080275613 | METHOD FOR OPERATING A MULTI-STEP AUTOMATIC TRANSMISSION - Described is a method for operating a multi-step automatic transmission, particularly an automatic transmission of a drive train of a vehicle with a combustion engine. In downshifting from the third gear ratio to a second gear ratio, higher inertias must be shifted than when shifting from the third gear ratio to the first gear ratio. According to the invention, when there is a demand for a coasting downshift from the third gear ratio to the second gear ratio or to the first gear ratio with no performance demand on the combustion engine, the coasting downshift to the second gear ratio is not executed, and the first gear ratio is engaged when the requirements for downshifting to the first gear ratio are met. | 11-06-2008 |
20080296124 | Hydraulic System in Motor Vehicles - A hydraulic system in motor vehicles with at least one hydraulically actuated clutch, which entails minimized control complexity for supplying the clutch with hydraulic oil and which takes up less structural space. These characteristics are achieved essentially in that the pressure control of the hydraulically actuated clutch is effected directly and exclusively by an electrically driven and electronically controlled oil pump. | 12-04-2008 |
20090112425 | Method for Operating an Automatic Gearbox - A method of operating an automatic transmission of a motor vehicle, in particular a variable-speed transmission. The automatic transmission includes at least five shift elements, at least three of which are engaged in a forward and a reverse gear to transfer torque or force. When disengaging gears for shifting the automatic transmission from a forward or reverse gear to a neutral position, at least one of the at least three shift elements that are engaged in the respective forward or reverse gear is completely disengaged. | 04-30-2009 |
20090176612 | Method for Operating an Automatic Gearbox - A method for operating an automatic transmission of a motor vehicle, in particular a variable-speed automatic transmission. The automatic transmission has five shift elements and for transferring torque or force in a forward gear and in a reverse gear at least three of the five shift elements are engaged. In a neutral position of the automatic transmission, to prevent torque or force flow at least one of the shift elements that are engaged in the respective forward or reverse gear is fully disengaged. | 07-09-2009 |
20090206292 | METHOD OF OPERATING A TRANSMISSION SYSTEM VALVE CONFIGURATION - The invention describes a method for operating a transmission's valve system of a vehicle's drive train through a valve unit and said valve unit's electro-magnetic activator configuration. In a transmission's hydraulic system and being part of the vehicle's drive train, its hydraulic pressure value (p_EDS) can be employed and adjusted through a valve unit's configuration by applying to the electro-magnetic activator system a pulse-width-modulated current signal (i_EDS). The pulse-width modulated current signal (i_EDS) and its signal's amplitude (A) and/or its pulse duration (pw | 08-20-2009 |
20090249777 | TRANSMISSION DEVICE WITH AT LEAST ONE FORM-FIT SHIFTING ELEMENT BEING HYDRAULICALLY ACTUATED VIA A HYDRAULIC SYSTEM - A transmission device ( | 10-08-2009 |
20090250310 | TRANSMISSION APPARATUS COMPRISING AT LEAST ONE POSITIVE SHIFTING ELEMENT HYDRAULICALLY ACTUATED BY WAY OF A HYDRAULIC SYSTEM - A transmission apparatus ( | 10-08-2009 |
20090280951 | METHOD FOR OPERATING A VEHICLE DRIVETRAIN - A method for operating a vehicle drivetrain ( | 11-12-2009 |
20100042302 | METHOD FOR THE EMERGENCY ACTUATION OF AN AUTOMATED DOUBLE CLUTCH TRANSMISSION OF A MOTOR VEHICLE - A method for emergency actuation of an automated dual-clutch transmission of a vehicle with electrohydraulic control via a transmission control device. The method includes disengaging one clutch of the dual-clutch transmission, in order to realize emergency operation of the transmission and applying pressure on the other clutch after an error signal is transmitted indicating a malfunction of the transmission and/or the transmission control device. In order to keep the complexity of the hardware of the hydraulic system low, both clutches are disengaged, when an error signal occurs, and adjusted to a safe initial state, and an actuating pressure is only re-applied to one of the two clutches after the initial state is reached. In addition to the already existing elements of the hydraulic system, only one device or software is required which detects and selects the clutch that is more advantageous for continued driving operation. | 02-18-2010 |
20100081543 | VALVE ARRANGEMENT IN A HYDRAULIC CONTROL UNIT - A pressure (p | 04-01-2010 |
20100204893 | PROCESS FOR MONITORING THE DIRECTION OF FRICTIONAL DRIVE FROM A VEHICLE TRANSMISSION AT NEAR-ZERO VEHICLE SPEED - A process of monitoring a drive direction of an automatic or automated vehicle transmission at near-zero vehicle speed via an engaged gear. A desired direction of drive of the transmission is determined from an engaged gear at the time the vehicle begins motion. An actual direction of drive is determined from the transmission and, if different from the desired direction of drive, an error signal is produced. The process includes determining the actual drive either from a sensed rotational direction of a transmission input shaft and a sensed rotational direction of a transmission output shaft or a sensed valve setting, a sensed pressure in an transmission electro-hydraulic control system or on a transmission shifting element or from a sensed direction of rotation of a transmission gearset element or from axial movement or force of a transmission constructional element. | 08-12-2010 |
20100216597 | HYDRAULIC SYSTEM OF A GEAR BOX - An automatic vehicle transmission comprises a first oil supply unit ( | 08-26-2010 |
20110027105 | OIL PUMP FOR AN AUTOMATIC TRANSMISSION AND CONTROL METHOD THERETO - A transmission oil pump for an automatic transmission of a motor vehicle. The speed of the oil pump can be shifted by a transmission ( | 02-03-2011 |
20110231074 | METHOD FOR THE OPERATION OF A DRIVETRAIN - A method of operating of a drivetrain, having a drive motor and an automatic transmission with at least five shift elements, to improve a shift speed of at least one of a successive upshift and a successive downshift, such that at least one required shift element is prepared so that, when a synchronization point is reached, the successive upshift or downshift can be immediately carried out. The method comprises the steps of requiring, at most, two of the at least five shift elements be disengaged and a remainder of the shift elements be engaged, in each of the gears; and preparing a shift element, to be engaged before reaching the synchronization point, by a first time interval, that is applied in a time-controlled manner or an event-controlled manner for engagement, while the first upshift or the first downshift is being carried out while giving consideration to the successive upshift or the successive downshift. | 09-22-2011 |
20110237390 | METHOD FOR THE OPERATION OF A DRIVETRAIN - A method of operating of a drivetrain, having at least a drive motor and an automatic transmission with at least five shift elements, to improve a shift speed such that during a first upshift or a first downshift, at least one required shift element is prepared such that, when a synchronization point is reached, the successive upshift or the successive downshift can be immediately carried out. The method comprises the steps of requiring, at most, two of the at least five shift elements be disengaged and a remainder of the shift elements be disengaged for each gear for transferring one of torque and force; and one of increasing and decreasing a torque of the drive motor, relative to a torque of the drive motor derived from a driver's wish, during one of the first upshift or downshift and the successive upshift or downshift to assist with an overlapped implementation of the successive upshifts or the successive downshifts. | 09-29-2011 |
20110263382 | METHOD FOR THE OPERATION OF A TRANSMISSION DEVICE - A method is described for the operation of a transmission device ( | 10-27-2011 |
20110284335 | METHOD FOR THE OPERATION OF A TRANSMISSION DEVICE OF A VEHICLE DRIVE TRAIN - A method of operating a transmission of a vehicle drive train with at least one drive machine. The transmission is formed with at least one interlocking shift element and a plurality of frictional shift elements in order to obtain various gear ratios. During an engaging process of the interlocking shift element, starting from a disengaged operating condition, in which halves of the interlocking shift element are out of engagement, to an engaged operating condition, in which the shift element halves are interlocked in a rotationally fixed manner, when interlock between the shift element halves is obstructed, a rotational speed difference is produced at least temporarily between the shift element halves, at which the interlock in the area of the interlocking shift element can be engaged. To produce the speed difference between the shift element halves, the transmission capacity of at least one frictional shift element is increased. | 11-24-2011 |
20120011842 | HYDRAULIC TRANSMISSION CONTROL - A hydraulic transmission unit comprises at least one pressure regulation valve ( | 01-19-2012 |
20120022752 | METHOD FOR OPERATING A VEHICLE DRIVE TRAIN - A method of operating a vehicle drive-train with an engine and a transmission during a gearshift in which an interlocking shift element is disengaged and a frictional shift element is engaged. Upon a shift command, the shifting time and a transmission input speed are monitored. If the input speed deviates from a synchronous speed equivalent to the gear ratio being disengaged, recognizing disengagement of the interlocking shifting element. If an engaged operating condition of the interlocking shifting element to be disengaged is detected, after the lapse of a time interval beginning with the shift command, a current drive torque of the drive machine is brought by motor actuation to a level that corresponds to a difference between the current transmission input torque and a torque that can be transmitted by the frictional shifting element to be engaged, operating with slip, plus a torque offset value. | 01-26-2012 |
20120272768 | DEVICE FOR OPERATING A TRANSMISSION APPARATUS HAVING A PLURALITY OF ELECTROHYDRAULICALLY ACTUATED FRICTION-FIT AND FORM-FIT SHIFT ELEMENTS - A mechanism for actuating a transmission having shifting elements. A self-holding valve device is movable into a first position, by a pilot pressure, against a force directed to a second position and held by a pressure holding signal in the first position. Transmission of a pressure signal, to a switching valve, is blocked by the self-holding valve device in the first position but, in the second position, is applied to the switching valve. When the driver sets the switching valve to a first shift position, the pressure signal can be applied to valve devices of at least two of the shifting elements that produce an actuating pressure and, in a second shift position of the switching valve, the onward transmission of the pressure signal, to the valve devices of the shifting elements that produce an actuating pressure, is blocked in the area of the switching valve. | 11-01-2012 |
20130047739 | DEVICE FOR DETERMINING AN OPERATING STATE OF AT LEAST ONE BIDIRECTIONALLY ACTUABLE HYDRAULIC ADJUSTING DEVICE OF A SHIFTING ELEMENT OF A TRANSMISSION DEVICE - A device for determining an operating state of a bi-directionally actuated hydraulic adjusting device of a transmission shifting element, which pressurizes active surfaces of a piston. The piston is biased to opposite end positions depending on which of a first active surface or a second active surface is pressurized with high pressure. The areas of the adjusting device, which can be pressurized with the pressure at the active surfaces of the piston, are connected with one another in positions of the piston element, between the end positions, via a throttle device. One of each area can be coupled for adjustment of the piston with the high-pressure area, and the other area with the low pressure area. An additional throttle device is provided upstream of the low pressure area and a pressure measuring device is provided upstream of the additional throttle device. | 02-28-2013 |