Abstract:
A hydraulic supply system for a hydraulically-operated automatic transmission includes a primary pump that is driven by an internal combustion engine of a vehicle. An electrically-driven auxiliary pump is provided to supply the system with hydraulic pressure when the primary pump is off or to supplement the primary pump when the primary pump does not deliver sufficient pressure. A discharge line from the auxiliary pump is connected to a control line of the hydraulic supply system and to the hydraulic system supply line under system pressure. Check valves are provided in the respective lines from the auxiliary pump. An additional check valve is provided in a line that extends from the control line to a torque sensing chamber of the automatic transmission.
Abstract:
A hydraulic system including a multi-flow hydraulic pressure supply unit, especially a dual-flow hydraulic pressure supply unit, such as a pump, by which a volumetric flow of pressurized fluid is supplied to a hydraulic-fluid-operated device. A valve arrangement is provided either for switching between the individual pump flows or for interconnecting the individual pump flows.
Abstract:
A hydraulic arrangement for controlling a transmission connected downstream of an internal combustion engine having a start-stop device. A hydraulic energy source provides hydraulic energy, an energy accumulator is connected downstream of the hydraulic energy source for storing and dispensing hydraulic energy provided by the hydraulic energy source, and a hydraulic controller is associated with the hydraulic energy source and the energy accumulator for controlling the transmission. The energy accumulator is associated with the hydraulic controller by a branch line to a pilot control circuit.
Abstract:
A hydraulic system having at least one hydraulic valve for controlling a transmission, in particular a continuously variable transmission. The hydraulic valve is controlled by a pilot circuit including at least one control element having a variable flow resistance and one control element having a constant flow resistance. The control element having a variable flow resistance is connected upstream of the control element having a constant flow resistance.
Abstract:
A hydraulic supply system for a hydraulically actuated automatic transmission, in particular for a belt-driven conical-pulley transmission. The system includes a primary pump driven by a primary drive system to provide pressure in a supply line connected to a regulating valve. The supply line is connected through a pilot valve to a control line in which a control valve is situated, with which the pressure that determines the setting of a transmission ratio adjusting valve is set. An auxiliary pump driven by an auxiliary drive system that is separate from the primary drive system includes an outlet line connected to the control line through a first valve that opens in the direction of the control line, and is connected to the supply line through a second valve that opens in the direction of the supply line.
Abstract:
A hydraulic system for actuating a belt-driven conical-pulley transmission having a variably adjustable transmission ratio, of a vehicle, including at least one hydraulic energy source and having a torque sensor that is supplied with working medium by a pump flow of the hydraulic energy source. A disconnection valve is connected between the hydraulic energy source and the torque sensor, which makes it possible to connect or disconnect an additional pump flow of the hydraulic energy source, depending on need.
Abstract:
A hydraulic system for controlling a belt-driven conical-pulley transmission. A pump draws a working medium from a working medium tank or through a cooler return valve from a cooler return line. The cooler return valve is a minimum pressure valve that holds closed a connection between the cooler return line and a pump inlet line through the cooler return valve, as long as the pressure in the cooler return line remains below a specified minimum pressure. The cooler return valve also opens the connection between the cooler return line and the pump inlet line through the cooler return valve as soon as the specified minimum pressure in the cooler return line is exceeded.
Abstract:
A hydraulic system for actuating a clutch and/or a variable speed drive unit of a belt-driven conical-pulley transmission of a vehicle, such as a commercial vehicle, and having a variable transmission ratio and a torque sensor. The hydraulic system includes at least one hydraulic energy source. A selector and check valve is provided for supplying additional components besides the torque sensor and is connected between the hydraulic energy source, the additional components, and the torque sensor in such a way that the torque sensor includes priority in being supplied with hydraulic medium.
Abstract:
A hydraulic system having at least one hydraulic valve for actuating a component, wherein a control pressure acting on the hydraulic valve can be activated through a supply pressure of a pilot circuit having at least one actuator. At least one pressure reduction apparatus is connected in series with the actuator.
Abstract:
A method for operating a continuously variable conical pulley transmission having two conical pulley sets that are operatively coupled by a endless torque-transmitting means, so that the transmission ratio between the conical pulley sets is continuously variable. A hydraulic medium is supplied to the continuously variable conical pulley transmission in a stop phase of a start/stop operation by means of a pump unit that includes a pump that is driven by an electric motor. The electric motor is controlled as a function of the temperature of the hydraulic medium.