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 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 transmission with a drive side and an output side conical disk pair. One conical disk pair includes a fixed disk carried by a shaft, a movable disk non-rotatably connected with and axially movable relative to the shaft, and a support ring axially attached to the shaft adjacent a back side of the movable disk. A pressure chamber between the support ring and the back side of the movable disk is supplied with hydraulic pressure medium through a passage in the shaft that opens to the surface of the shaft. An end region of the movable disk when moved along the shaft passes over the opening at a maximum spacing of the movable disk from the fixed disk, and a hydraulic medium connection exists between the passage and the pressure chamber through drainage slots between an inner surface of the movable disk and the peripheral surface of the shaft.
Abstract:
A continuously variable transmission for a motor vehicle. The transmission includes an adjustable width drive pulley and an adjustable width output pulley that are drivingly connected by an endless torque-transmitting member. The drive pulley includes a spring to bias the movable element of the pulley toward a position at which the spacing between the conical disks that define the pulley are at a minimum, to avoid damage to the transmission when the vehicle is being towed.