Zf Friedrichshafen Ag

Armin Haugg

Thilo Schmidt

Markus Herrmann

Alexander Haberstock

Christian Popp

Florian Weinl

Thomas Schwegler

Julia Klein

Michael Jud

Christian Schupp

A hydraulic control unit () for an automatic transmission of a motor vehicle includes a volumetric flow rate control valve (). The hydraulic control unit () is configured for delivering hydraulic fluid to an inlet () of the volumetric flow rate control valve (). An outlet () of the volumetric flow rate control valve () is connected to a torque converter torus of the automatic transmission. In addition, the volumetric flow rate control valve () is configured for directing the hydraulic fluid across an orifice (), so that the pressure of the hydraulic fluid is reduced and a constant flow of hydraulic fluid is feedable to a torque converter torus.

Hydraulic control unit for an automatic transmission of a motor vehicle

A cooling prioritization valve () for a hydraulic system () of a motor vehicle transmission () includes a valve housing (), a valve slide (), an inlet (), an outlet (), and a further outlet (). A secondary system pressure circuit () of the hydraulic system () can be connected to the inlet (), a cooler () can be connected to the outlet () or to the further outlet (), and a suction loading () can be connected to the outlet () or to the further outlet (). In a starting position, the inlet () is not connected either to the outlet () or to the further outlet (). In a first control position, the inlet () is connected to the outlet (). In a second control position, the inlet () is connected to the outlet () and the further outlet ().

Cooling-prioritization valve for a hydraulic system of a motor vehicle transmission

A parking lock for a transmission of a motor vehicle having an interlocking element of a connecting rod that is biased against a parking lock disengagement direction to bring and keep a ratchet tooth of a locking pawl in engagement with a tooth space of a parking interlock gear during an engagement of the parking lock. The connecting rod is provided a spring force acting in a parking lock engagement direction from an inserting spring and a compressive force acting in the parking lock disengagement direction from a hydraulically actuatable actuator having first piston pressurizable to disengage the parking lock. A detent device actuatable by an electromagnet mechanically fixes the first piston in either a latched or unlatched piston position associated with an engaged or disengaged position of the parking lock, respectively. A system determines a current engagement position of the detent device by assessing an inductance at the electromagnet.

Parking interlock in a vehicular transmission

A hydraulic system for a transmission of a motor vehicle, the system having first and second pumps for conveying hydraulic fluid into primary and/or system-pressure circuits so that an intended pressure prevails in the circuits. The system further including liquid retention means preventing a flow of hydraulic fluid conveyed by the second pump from being conducted through the first pump when the first pump is not conveying and the second pump is conveying, and preventing a flow of hydraulic fluid conveyed by the first pump from being conducted through the second pump when the second pump is not conveying and the first pump is conveying. The system additionally including a sailing-mode lubricating valve for controlling, by an open-loop system, a flow rate of hydraulic fluid conveyed by the second pump into the primary and/or secondary system-pressure circuits such that the intended pressure is set in the system-pressure circuits.

Hydraulic system for a transmission of a motor vehicle

An actuation arrangement () including an actuating device for actuating a transmission parking lock (). The actuating device having a piston () movable into an engaged position (E), which engages the transmission parking lock (), and into a disengaged position (A), which disengages the transmission parking lock (). The actuating device further has a cylinder () including a cavity (), in which the piston () is arranged and into which transmission oil is supplied to move the piston (), and a locking unit () configured for selectively fixing the piston (). The actuation arrangement further includes a valve (). When the valve () is in a first valve position, transmission oil is supplied to the transmission shift element () through a first line (), to actuate the transmission shift element (), and into the cavity () through the second line (), to actuate the transmission parking lock ().

Growing community of inventors

Friedrichshafen, Germany

Armin Haugg