Abstract: A hydraulic circuit for a toroidal transmission comprises: a) a single pump, b) a main pressure controller connected to the pump to generate a main line pressure in a main line, c) a roller controller connected to the main line to generate two roller control pressures from the main line pressure, d) at least one hydraulic roller actuator for adjusting a roller in a toroidal space set up by two disks, the roller actuator being connected to the roller controller, e) a disk controller connected to the main line, a disk control pressure being generated in the disk controller from the main line pressure, and f) at least one hydraulic disk actuator for axially adjusting at least one of the disks, the disk actuator being connected to the disk controller.

Abstract: A method for controlling a hydraulic circuit for a twin-clutch transmission, wherein the hydraulic circuit comprises a first and a second clutch that can be hydraulically actuated, the pressures of said clutches being controlled with respective pressure control valves, and wherein a safety circuit substantially guarantees a safe state for the hydraulic circuit if a malfunction occurs. The safety circuit is configured such that if a partial malfunction affecting only one of the two clutches occurs, the affected clutch is disengaged and if a total malfunction affecting both clutches occurs, the clutch with the lower clutch pressure at the time of the total malfunction is disengaged and the other clutch with the higher clutch pressure at the time of the total malfunction remains engaged to maintain the transfer of torque via said clutch.

Abstract: A hydraulic circuit for the control of a double clutch transmission which has two transmission groups, each with an isolating clutch and with a plurality of shift clutches for the engagement and disengagement of gear steps, the hydraulic circuit having for each transmission group a specific hydraulic branch connected to a pump in each case via a safety valve, and each hydraulic branch having in each case a clutch control valve for controlling the assigned isolating clutch and at least one shift control valve for controlling the assigned shift clutches. Here, the safety valves are designed in each case as proportional pressure regulating valves.

Abstract: A hydraulic circuit for a toroidal transmission comprises: a) a single pump, b) a main pressure controller connected to the pump to generate a main line pressure in a main line, c) a roller controller connected to the main line to generate two roller control pressures from the main line pressure, d) at least one hydraulic roller actuator for adjusting a roller in a toroidal space set up by two disks, the roller actuator being connected to the roller controller, e) a disk controller connected to the main line, a disk control pressure being generated in the disk controller from the main line pressure, and f) at least one hydraulic disk actuator for axially adjusting at least one of the disks, the disk actuator being connected to the disk controller.

Abstract: A method for controlling a hydraulic circuit for a twin-clutch transmission, wherein the hydraulic circuit comprises a first and a second clutch that can be hydraulically actuated, the pressures of said clutches being controlled with respective pressure control valves, and wherein a safety circuit substantially guarantees a safe state for the hydraulic circuit if a malfunction occurs. The safety circuit is configured such that if a partial malfunction affecting only one of the two clutches occurs, the affected clutch is disengaged and if a total malfunction affecting both clutches occurs, the clutch with the lower clutch pressure at the time of the total malfunction is disengaged and the other clutch with the higher clutch pressure at the time of the total malfunction remains engaged to maintain the transfer of torque via said clutch.

Abstract: A hydraulic circuit for the control of a double clutch transmission which has two transmission groups, each with an isolating clutch and with a plurality of shift clutches for the engagement and disengagement of gear steps, the hydraulic circuit having for each transmission group a specific hydraulic branch connected to a pump in each case via a safety valve, and each hydraulic branch having in each case a clutch control valve for controlling the assigned isolating clutch and at least one shift control valve for controlling the assigned shift clutches. Here, the safety valves are designed in each case as proportional pressure regulating valves.

Abstract: A hydraulic circuit, particularly any for an automated twin clutch transmission for motor vehicles, including a countershaft with two parallel power transmission branches, two clutches, a high pressure circuit having at least one actuator for the countershaft transmission and/or the clutches, a low pressure circuit for lubrication and/or cooling of elements of the twin clutch transmission, and a first adjustment pump for the high pressure circuit. The low pressure circuit includes a plurality of secondary pumps which are connected in parallel to the first adjustment pump.

Abstract: A hydraulic circuit, particularly for an automated twin clutch transmission for motor vehicles, comprises a countershaft transmission with two parallel power transmission branches, and two clutches, comprising:

Abstract: A hydraulic actuator and a method for degassing hydraulic actuators having t least two chambers are disclosed. For actuating a hydraulic element, for example a piston in a piston-and-cylinder unit the hydraulic actuator may be supplied with pressurized hydraulic fluid from a hydraulic source via gate valves. The chambers may be interconnected via another gate valve such that when the other gate valve is open, a closed flushing circuit may be configured, starting from a hydraulic fluid container via a hydraulic pump, a first gate valve, a first chamber, the additional valve, a second chamber, a second gate valve and back to the hydraulic fluid container.