Audi Ag

Volkswagen Ag

Dietmar Schuller

Hans-Peter Fleischmann

Stefan Ammler

Roland Meyer

Andreas Deimel

Martin Bauer

Oliver Rang

Christian Corell

Mathias Jakob-Bodenhagen

Michael Schöffmann

Stephan Herold

Josef Aggstaller

An electromagnetic valve for a hydraulic system for an automatic transmission of a vehicle. An armature chamber is filled with hydraulic medium and fluidically connected to hydraulic lines of the hydraulic system. An armature is mounted in the armature chamber such that its stroke is adjustable. The armature includes a shut-off body and divides the armature chamber into an opening-side chamber facing the flow opening and into an inner chamber facing away from the flow opening. During a stroke of the armature, an oil exchange occurs, and a displacement volume of the hydraulic medium overflows from the opening-side chamber into the inner chamber. A hydraulic line leading to the opening-side chamber or to the inner chamber of the armature chamber includes a dirt collecting element that is designed as a permanent magnet and that retains contaminations in the hydraulic medium that flows through the hydraulic line during an oil exchange.

Electromagnet for a hydraulic system

An electromagnet for a hydraulic system, such as an automatic transmission of a motor vehicle. The electromagnet may include an armature chamber filled with hydraulic medium, which may be fluidically connected to hydraulic lines of the hydraulic system, and may have an armature mounted therein. The armature may have an adjustable stroke and may include a shut-off body. The armature may divide the armature chamber into an opening-side chamber facing the flow opening, and an inner chamber facing away from it. During a stroke movement of the armature, an oil exchange may occur, during which a displacement volume of the hydraulic medium overflows from the opening-side chamber into the inner chamber. The electromagnet may further include a hydraulic medium reservoir, which may store a hydraulic medium having a higher degree of purity than the hydraulic medium in the hydraulic lines and which may be fluidically connected to the opening-side chamber.

A method for operating a fluid circuit of a motor vehicle, used for operating via a main circuit, and with a secondary circuit that is connected through a mechanical thermostatic valve to the main circuit, and an electric fluid conveying device for conveying a fluid. In a test mode, during a test period, the fluid conveying device is adjusted to a test operational speed and the actual amperage of the current required for the fluid conveying device is determined, wherein with an actual temperature of the fluid, which is lower than a switching temperature of the thermostatic value, the actual current amperage is stored as the first amperage value, and with an actual temperature, which is higher than the switching temperature, a second amperage value is stored, so that a proper function of the thermostatic valve is recognized when the second amperage is higher than the first amperage value.

Method for operating a fluid circuit of a motor vehicle, and corresponding fluid circuit

According to a method for operating a clutch transmission, especially a dual clutch transmission, which includes a hydraulic circuit having at least one pump for delivering hydraulic medium and at least one pressure accumulator for accommodating and making available a hydraulic medium under pressure, the pump associated with an electric motor is operated depending on a charge requirement of the pressure accumulator. To determine the charge requirement, the pump is driven by the electric motor, and the current consumed by the electric motor in the process is detected to determine the charge requirement.

Method for operating a clutch transmission, clutch transmission

An actuator for activating a parking lock, in particular for automatic transmissions in motor vehicles, includes a hydraulic piston which is guided in a cylinder and which activates a locking pawl for a parking lock wheel in the transmission by way of an actuating rod. The piston disengages the parking lock against the force of a preload spring which engages the parking lock in the pressureless state. An electromagnetically activated locking device can positively secure the piston in the disengaged position, with the locking device securing the piston relative to a guide sleeve attached to the cylinder with radially extendable locking elements. To improve system protection, the piston can also be secured in a positively locking fashion by the locking device in the position corresponding to the engaged state of the parking lock.

Actuator for actuating a parking lock

A clutch transmission, in particular a dual clutch transmission, includes a hydraulic circuit for actuating and/or cooling the clutch transmission. The hydraulic circuit includes at least one cooler for cooling a hydraulic medium conveyed by at least one pump, wherein a bypass with a thermostatic bypass valve is associated with the cooler. The thermostatic bypass valve has hereby three switching positions, wherein it can be moved to a first switching position by a spring force, from the first switching position to the second switching position by a thermal element against the spring force and from the second switching position to a third switching position against the spring force by a pressure difference exceeding a predeterminable limit value.

Clutch transmission

A ventilation device for a hydraulic cylinder providing a housing having a fluid passageway with an inlet and an outlet, and a closure member disposed in said passageway displaceable in obstructing relation with such inlet upon application of a first fluid force in such inlet, obstructing relation with such outlet upon application of a second fluid force on such inlet and in nonobstructing relation with either of such inlet and outlet upon application of a third fluid force between such first and second fluid forces.

Ventilation device for a hydraulic cylinder

A device for operating a parking brake of a motor vehicle, wherein the parking lock includes an actuatable actuator element for disengaging the parking lock counter to a restoring pressure, and an actuatable holding device for holding the parking lock when the latter is disengaged. The device includes a selector control lever and a transmission control device communicating therewith, the selector control device actuating the holding device and the transmission control device actuating the actuator element.

Device for operating a parking lock of a motor vehicle and corresponding method

A dual clutch transmission, in particular of a motor vehicle, includes a hydraulic circuit for cooling the dual clutch transmission, wherein the hydraulic circuit includes at least one pump for conveying a hydraulic medium flow, at least one cooler for cooling the hydraulic medium flow, and a volume control valve for adjusting the hydraulic medium flow for at least one cooling system associated with clutches of the dual clutch transmission. The volume control valve is designed to convey the hydraulic medium flow in a first switching state to a first cooling system associated with a first of the clutches, and in at least one second switching state to a second cooling system associated with a second of the clutches.

Hydraulic circuit, method for operating the same

A clutch transmission, in particular a dual-clutch transmission for a vehicle, such as a motor vehicle, includes at least one automatic transmission with a hydraulically actuatable clutch and at least one hydraulically actuatable gear actuator, and a hydraulic circuit having a tank supplying an unpressurized hydraulic medium and a pressure source supplying a pressurized hydraulic medium. For operating the respective clutch, a first pressure control valve and at least one second pressure control valve are arranged upstream of the respective coupling. At least one of the pressure control valves is connected with an upstream switching device which connects the at least one pressure control valve and a hydraulically actuatable parking lock either with the pressure source or with the tank.

Growing community of inventors

Altmannstein, Germany

Dietmar Schuller